vendor: remove vendor directory from Git, rely on module system

This commit is contained in:
mappu 2020-07-25 13:05:31 +12:00
parent d5f3307f01
commit a041f0ba5c
64 changed files with 0 additions and 19673 deletions

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cmd/gopngquant/gopngquant
cmd/gopngquant/gopngquant.exe

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/*
Copyright (c) 2016, The go-imagequant author(s)
Permission to use, copy, modify, and/or distribute this software for any purpose
with or without fee is hereby granted, provided that the above copyright notice
and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.
*/
package imagequant
import (
"errors"
)
/*
#include "libimagequant.h"
*/
import "C"
type Attributes struct {
p *C.struct_liq_attr
}
// Callers MUST call Release() on the returned object to free memory.
func NewAttributes() (*Attributes, error) {
pAttr := C.liq_attr_create()
if pAttr == nil { // nullptr
return nil, errors.New("Unsupported platform")
}
return &Attributes{p: pAttr}, nil
}
const (
COLORS_MIN = 2
COLORS_MAX = 256
)
func (this *Attributes) SetMaxColors(colors int) error {
return translateError(C.liq_set_max_colors(this.p, C.int(colors)))
}
func (this *Attributes) GetMaxColors() int {
return int(C.liq_get_max_colors(this.p))
}
const (
QUALITY_MIN = 0
QUALITY_MAX = 100
)
func (this *Attributes) SetQuality(minimum, maximum int) error {
return translateError(C.liq_set_quality(this.p, C.int(minimum), C.int(maximum)))
}
func (this *Attributes) GetMinQuality() int {
return int(C.liq_get_min_quality(this.p))
}
func (this *Attributes) GetMaxQuality() int {
return int(C.liq_get_max_quality(this.p))
}
const (
SPEED_SLOWEST = 1
SPEED_DEFAULT = 3
SPEED_FASTEST = 10
)
func (this *Attributes) SetSpeed(speed int) error {
return translateError(C.liq_set_speed(this.p, C.int(speed)))
}
func (this *Attributes) GetSpeed() int {
return int(C.liq_get_speed(this.p))
}
func (this *Attributes) SetMinOpacity(min int) error {
return translateError(C.liq_set_min_opacity(this.p, C.int(min)))
}
func (this *Attributes) GetMinOpacity() int {
return int(C.liq_get_min_opacity(this.p))
}
func (this *Attributes) SetMinPosterization(bits int) error {
return translateError(C.liq_set_min_posterization(this.p, C.int(bits)))
}
func (this *Attributes) GetMinPosterization() int {
return int(C.liq_get_min_posterization(this.p))
}
func (this *Attributes) SetLastIndexTransparent(is_last int) {
C.liq_set_last_index_transparent(this.p, C.int(is_last))
}
func (this *Attributes) CreateHistogram() *Histogram {
ptr := C.liq_histogram_create(this.p)
return &Histogram{p: ptr}
}
// Free memory. Callers must not use this object after Release has been called.
func (this *Attributes) Release() {
C.liq_attr_destroy(this.p)
}

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libimagequant is derived from code by Jef Poskanzer and Greg Roelofs
licensed under pngquant's original license (at the end of this file),
and contains extensive changes and additions by Kornel Lesiński
licensed under GPL v3.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
libimagequant © 2009-2016 by Kornel Lesiński.
GNU GENERAL PUBLIC LICENSE
Version 3, 29 June 2007
Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
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15. Disclaimer of Warranty.
THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
16. Limitation of Liability.
IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.
17. Interpretation of Sections 15 and 16.
If the disclaimer of warranty and limitation of liability provided
above cannot be given local legal effect according to their terms,
reviewing courts shall apply local law that most closely approximates
an absolute waiver of all civil liability in connection with the
Program, unless a warranty or assumption of liability accompanies a
copy of the Program in return for a fee.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
© 1989, 1991 by Jef Poskanzer.
© 1997, 2000, 2002 by Greg Roelofs.
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted, provided
that the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation. This software is provided "as is" without express or
implied warranty.

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@ -1,45 +0,0 @@
/*
Copyright (c) 2016, The go-imagequant author(s)
Permission to use, copy, modify, and/or distribute this software for any purpose
with or without fee is hereby granted, provided that the above copyright notice
and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.
*/
package imagequant
/*
#include "libimagequant.h"
*/
import "C"
type Histogram struct {
p *C.struct_liq_histogram
}
func (this *Histogram) AddImage(attr *Attributes, img *Image) error {
return translateError(C.liq_histogram_add_image(this.p, attr.p, img.p))
}
func (this *Histogram) Quantize(attr *Attributes) (*Result, error) {
res := Result{}
liqerr := C.liq_histogram_quantize(this.p, attr.p, &res.p)
if liqerr != C.LIQ_OK {
return nil, translateError(liqerr)
}
return &res, nil
}
// Free memory. Callers must not use this object after Release has been called.
func (this *Histogram) Release() {
C.liq_histogram_destroy(this.p)
}

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/*
Copyright (c) 2016, The go-imagequant author(s)
Permission to use, copy, modify, and/or distribute this software for any purpose
with or without fee is hereby granted, provided that the above copyright notice
and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.
*/
package imagequant
import (
"errors"
"unsafe"
)
/*
#include "libimagequant.h"
*/
import "C"
type Image struct {
p *C.struct_liq_image
w, h int
released bool
}
// Callers MUST call Release() on the returned object to free memory.
func NewImage(attr *Attributes, rgba32data string, width, height int, gamma float64) (*Image, error) {
pImg := C.liq_image_create_rgba(attr.p, unsafe.Pointer(C.CString(rgba32data)), C.int(width), C.int(height), C.double(gamma))
if pImg == nil {
return nil, errors.New("Failed to create image (invalid argument)")
}
return &Image{
p: pImg,
w: width,
h: height,
released: false,
}, nil
}
// Free memory. Callers must not use this object after Release has been called.
func (this *Image) Release() {
C.liq_image_destroy(this.p)
this.released = true
}
func (this *Image) Quantize(attr *Attributes) (*Result, error) {
res := Result{
im: this,
}
liqerr := C.liq_image_quantize(this.p, attr.p, &res.p)
if liqerr != C.LIQ_OK {
return nil, translateError(liqerr)
}
return &res, nil
}

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@ -1,65 +0,0 @@
# imagequant
Go bindings for libimagequant
`libimagequant` is a library for lossy recompression of PNG images to reduce their filesize. It is used by the `pngquant` tool. This `go-imagequant` project is a set of bindings for libimagequant to enable its use from the Go programming language.
This binding was written by hand. The result is somewhat more idiomatic than an automated conversion, but some `defer foo.Release()` calls are required for memory management.
Written in Golang
## Usage
Usage example is provided by a sample utility `cmd/gopngquant` which mimics some functionality of the upstream `pngquant`.
The sample utility has the following options:
```
Usage of gopngquant:
-In string
Input filename
-Out string
Output filename
-Speed int
Speed (1 slowest, 10 fastest) (default 3)
-Version
```
## Building
This package can be installed via go get: `go get code.ivysaur.me/imagequant`
[go-get]code.ivysaur.me/imagequant git https://git.ivysaur.me/code.ivysaur.me/imagequant.git[/go-get]
The expected package path is `code.ivysaur.me/imagequant`. Build via `go build`.
This is a CGO package and requires a C compiler installed. However, if you use `go install` then future invocations of `go build` do not require the C compiler to be present.
The `imagequant.go` file also declares a number of `CFLAGS` for GCC that allow the included libimagequant (2.8 git-a425e83) to build in an optimal way without using the upstream configure/make scripts.
## License
I am releasing this binding under the ISC license, however, `libimagequant` itself is released under GPLv3-or-later and/or commercial licenses. You must comply with the terms of such a license when using this binding in a Go project.
## Changelog
2018-12-31 v2.12.2-go1.2
- go-imagequant: Update bundled libimagequant from 2.9.0 to 2.12.2
- build: Switch to Go Modules
- build: Update bundled CFLAGS for new CGo whitelist (reduces performance)
- build: Remove nonportable Cygwin makefile
2017-03-03 v2.9.0-go1.1
- *Previously tagged as 2.9go1.1*
- go-imagequant: Update bundled libimagequant from 2.8.0 to 2.9.0
- go-imagequant: Separate `CGO_LDFLAGS` for Linux and Windows targets
- gopngquant: Fix an issue with non-square images
2016-11-24 v2.8.0-go1.0
- *Previously tagged as 2.8go1.0*
- Initial public release
## See also
- Pngquant homepage https://pngquant.org/
- Pngquant source code https://github.com/pornel/pngquant
- Libimagequant source code https://github.com/ImageOptim/libimagequant

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/*
Copyright (c) 2016, The go-imagequant author(s)
Permission to use, copy, modify, and/or distribute this software for any purpose
with or without fee is hereby granted, provided that the above copyright notice
and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.
*/
package imagequant
import (
"image/color"
"unsafe"
)
/*
#include "libimagequant.h"
*/
import "C"
// Callers must not use this object once Release has been called on the parent
// Image struct.
type Result struct {
p *C.struct_liq_result
im *Image
}
func (this *Result) SetDitheringLevel(dither_level float32) error {
return translateError(C.liq_set_dithering_level(this.p, C.float(dither_level)))
}
func (this *Result) GetQuantizationError() float64 {
return float64(C.liq_get_quantization_error(this.p))
}
func (this *Result) GetRemappingError() float64 {
return float64(C.liq_get_remapping_error(this.p))
}
func (this *Result) GetQuantizationQuality() float64 {
return float64(C.liq_get_quantization_quality(this.p))
}
func (this *Result) GetRemappingQuality() float64 {
return float64(C.liq_get_remapping_quality(this.p))
}
func (this *Result) SetOutputGamma(gamma float64) error {
return translateError(C.liq_set_output_gamma(this.p, C.double(gamma)))
}
func (this *Result) GetImageWidth() int {
// C.liq_image_get_width
return this.im.w
}
func (this *Result) GetImageHeight() int {
// C.liq_image_get_height
return this.im.h
}
func (this *Result) GetOutputGamma() float64 {
return float64(C.liq_get_output_gamma(this.p))
}
func (this *Result) WriteRemappedImage() ([]byte, error) {
if this.im.released {
return nil, ErrUseAfterFree
}
buff_size := this.im.w * this.im.h
buff := make([]byte, buff_size)
iqe := C.liq_write_remapped_image(this.p, this.im.p, unsafe.Pointer(&buff[0]), C.size_t(buff_size))
if iqe != C.LIQ_OK {
return nil, translateError(iqe)
}
return buff, nil
}
func (this *Result) GetPalette() color.Palette {
ptr := C.liq_get_palette(this.p) // copy struct content
max := int(ptr.count)
ret := make([]color.Color, max)
for i := 0; i < max; i += 1 {
ret[i] = color.RGBA{
R: uint8(ptr.entries[i].r),
G: uint8(ptr.entries[i].g),
B: uint8(ptr.entries[i].b),
A: uint8(ptr.entries[i].a),
}
}
return ret
}
// Free memory. Callers must not use this object after Release has been called.
func (this *Result) Release() {
C.liq_result_destroy(this.p)
}

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@ -1,132 +0,0 @@
/*
© 2011-2015 by Kornel Lesiński.
This file is part of libimagequant.
libimagequant is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
libimagequant is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with libimagequant. If not, see <http://www.gnu.org/licenses/>.
*/
#include "libimagequant.h"
#include "pam.h"
#include "blur.h"
/*
Blurs image horizontally (width 2*size+1) and writes it transposed to dst (called twice gives 2d blur)
*/
static void transposing_1d_blur(unsigned char *restrict src, unsigned char *restrict dst, unsigned int width, unsigned int height, const unsigned int size)
{
assert(size > 0);
for(unsigned int j=0; j < height; j++) {
unsigned char *restrict row = src + j*width;
// accumulate sum for pixels outside line
unsigned int sum;
sum = row[0]*size;
for(unsigned int i=0; i < size; i++) {
sum += row[i];
}
// blur with left side outside line
for(unsigned int i=0; i < size; i++) {
sum -= row[0];
sum += row[i+size];
dst[i*height + j] = sum / (size*2);
}
for(unsigned int i=size; i < width-size; i++) {
sum -= row[i-size];
sum += row[i+size];
dst[i*height + j] = sum / (size*2);
}
// blur with right side outside line
for(unsigned int i=width-size; i < width; i++) {
sum -= row[i-size];
sum += row[width-1];
dst[i*height + j] = sum / (size*2);
}
}
}
/**
* Picks maximum of neighboring pixels (blur + lighten)
*/
LIQ_PRIVATE void liq_max3(unsigned char *src, unsigned char *dst, unsigned int width, unsigned int height)
{
for(unsigned int j=0; j < height; j++) {
const unsigned char *row = src + j*width,
*prevrow = src + (j > 1 ? j-1 : 0)*width,
*nextrow = src + MIN(height-1,j+1)*width;
unsigned char prev,curr=row[0],next=row[0];
for(unsigned int i=0; i < width-1; i++) {
prev=curr;
curr=next;
next=row[i+1];
unsigned char t1 = MAX(prev,next);
unsigned char t2 = MAX(nextrow[i],prevrow[i]);
*dst++ = MAX(curr,MAX(t1,t2));
}
unsigned char t1 = MAX(curr,next);
unsigned char t2 = MAX(nextrow[width-1],prevrow[width-1]);
*dst++ = MAX(t1,t2);
}
}
/**
* Picks minimum of neighboring pixels (blur + darken)
*/
LIQ_PRIVATE void liq_min3(unsigned char *src, unsigned char *dst, unsigned int width, unsigned int height)
{
for(unsigned int j=0; j < height; j++) {
const unsigned char *row = src + j*width,
*prevrow = src + (j > 1 ? j-1 : 0)*width,
*nextrow = src + MIN(height-1,j+1)*width;
unsigned char prev,curr=row[0],next=row[0];
for(unsigned int i=0; i < width-1; i++) {
prev=curr;
curr=next;
next=row[i+1];
unsigned char t1 = MIN(prev,next);
unsigned char t2 = MIN(nextrow[i],prevrow[i]);
*dst++ = MIN(curr,MIN(t1,t2));
}
unsigned char t1 = MIN(curr,next);
unsigned char t2 = MIN(nextrow[width-1],prevrow[width-1]);
*dst++ = MIN(t1,t2);
}
}
/*
Filters src image and saves it to dst, overwriting tmp in the process.
Image must be width*height pixels high. Size controls radius of box blur.
*/
LIQ_PRIVATE void liq_blur(unsigned char *src, unsigned char *tmp, unsigned char *dst, unsigned int width, unsigned int height, unsigned int size)
{
assert(size > 0);
if (width < 2*size+1 || height < 2*size+1) {
return;
}
transposing_1d_blur(src, tmp, width, height, size);
transposing_1d_blur(tmp, dst, height, width, size);
}

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LIQ_PRIVATE void liq_blur(unsigned char *src, unsigned char *tmp, unsigned char *dst, unsigned int width, unsigned int height, unsigned int size);
LIQ_PRIVATE void liq_max3(unsigned char *src, unsigned char *dst, unsigned int width, unsigned int height);
LIQ_PRIVATE void liq_min3(unsigned char *src, unsigned char *dst, unsigned int width, unsigned int height);

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@ -1,9 +0,0 @@
//+build !windows
package imagequant
/*
#cgo CFLAGS: -O3 -fopenmp -fomit-frame-pointer -Wall -Wno-attributes -std=c99 -DNDEBUG -DUSE_SSE=1 -msse
#cgo LDFLAGS: -lm -fopenmp -ldl
*/
import "C"

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//+build windows
package imagequant
/*
#cgo CFLAGS: -O3 -fno-math-errno -fopenmp -funroll-loops -fomit-frame-pointer -Wall -Wno-attributes -std=c99 -DNDEBUG -DUSE_SSE=1 -msse -fexcess-precision=fast
#cgo LDFLAGS: -fopenmp -static
*/
import "C"

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@ -1 +0,0 @@
module code.ivysaur.me/imagequant

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/*
Copyright (c) 2016, The go-imagequant author(s)
Permission to use, copy, modify, and/or distribute this software for any purpose
with or without fee is hereby granted, provided that the above copyright notice
and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.
*/
package imagequant
import (
"errors"
)
/*
#include "libimagequant.h"
const char* liqVersionString() {
return LIQ_VERSION_STRING;
}
*/
import "C"
var (
ErrQualityTooLow = errors.New("Quality too low")
ErrValueOutOfRange = errors.New("Value out of range")
ErrOutOfMemory = errors.New("Out of memory")
ErrAborted = errors.New("Aborted")
ErrBitmapNotAvailable = errors.New("Bitmap not available")
ErrBufferTooSmall = errors.New("Buffer too small")
ErrInvalidPointer = errors.New("Invalid pointer")
ErrUseAfterFree = errors.New("Use after free")
)
func translateError(iqe C.liq_error) error {
switch iqe {
case C.LIQ_OK:
return nil
case (C.LIQ_QUALITY_TOO_LOW):
return ErrQualityTooLow
case (C.LIQ_VALUE_OUT_OF_RANGE):
return ErrValueOutOfRange
case (C.LIQ_OUT_OF_MEMORY):
return ErrOutOfMemory
case (C.LIQ_ABORTED):
return ErrAborted
case (C.LIQ_BITMAP_NOT_AVAILABLE):
return ErrBitmapNotAvailable
case (C.LIQ_BUFFER_TOO_SMALL):
return ErrBufferTooSmall
case (C.LIQ_INVALID_POINTER):
return ErrInvalidPointer
default:
return errors.New("Unknown error")
}
}
func GetLibraryVersion() int {
return int(C.liq_version())
}
func GetLibraryVersionString() string {
return C.GoString(C.liqVersionString())
}

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@ -1,93 +0,0 @@
/*
** © 2011-2016 by Kornel Lesiński.
** See COPYRIGHT file for license.
*/
#include "libimagequant.h"
#include "pam.h"
#include "kmeans.h"
#include "nearest.h"
#include <stdlib.h>
#include <string.h>
#ifdef _OPENMP
#include <omp.h>
#else
#define omp_get_max_threads() 1
#define omp_get_thread_num() 0
#endif
/*
* K-Means iteration: new palette color is computed from weighted average of colors that map to that palette entry.
*/
LIQ_PRIVATE void kmeans_init(const colormap *map, const unsigned int max_threads, kmeans_state average_color[])
{
memset(average_color, 0, sizeof(average_color[0])*(KMEANS_CACHE_LINE_GAP+map->colors)*max_threads);
}
LIQ_PRIVATE void kmeans_update_color(const f_pixel acolor, const float value, const colormap *map, unsigned int match, const unsigned int thread, kmeans_state average_color[])
{
match += thread * (KMEANS_CACHE_LINE_GAP+map->colors);
average_color[match].a += acolor.a * value;
average_color[match].r += acolor.r * value;
average_color[match].g += acolor.g * value;
average_color[match].b += acolor.b * value;
average_color[match].total += value;
}
LIQ_PRIVATE void kmeans_finalize(colormap *map, const unsigned int max_threads, const kmeans_state average_color[])
{
for (unsigned int i=0; i < map->colors; i++) {
double a=0, r=0, g=0, b=0, total=0;
// Aggregate results from all threads
for(unsigned int t=0; t < max_threads; t++) {
const unsigned int offset = (KMEANS_CACHE_LINE_GAP+map->colors) * t + i;
a += average_color[offset].a;
r += average_color[offset].r;
g += average_color[offset].g;
b += average_color[offset].b;
total += average_color[offset].total;
}
if (total && !map->palette[i].fixed) {
map->palette[i].acolor = (f_pixel){
.a = a / total,
.r = r / total,
.g = g / total,
.b = b / total,
};
map->palette[i].popularity = total;
}
}
}
LIQ_PRIVATE double kmeans_do_iteration(histogram *hist, colormap *const map, kmeans_callback callback)
{
const unsigned int max_threads = omp_get_max_threads();
LIQ_ARRAY(kmeans_state, average_color, (KMEANS_CACHE_LINE_GAP+map->colors) * max_threads);
kmeans_init(map, max_threads, average_color);
struct nearest_map *const n = nearest_init(map);
hist_item *const achv = hist->achv;
const int hist_size = hist->size;
double total_diff=0;
#pragma omp parallel for if (hist_size > 2000) \
schedule(static) default(none) shared(average_color,callback) reduction(+:total_diff)
for(int j=0; j < hist_size; j++) {
float diff;
unsigned int match = nearest_search(n, &achv[j].acolor, achv[j].tmp.likely_colormap_index, &diff);
achv[j].tmp.likely_colormap_index = match;
total_diff += diff * achv[j].perceptual_weight;
kmeans_update_color(achv[j].acolor, achv[j].perceptual_weight, map, match, omp_get_thread_num(), average_color);
if (callback) callback(&achv[j], diff);
}
nearest_free(n);
kmeans_finalize(map, max_threads, average_color);
return total_diff / hist->total_perceptual_weight;
}

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#ifndef KMEANS_H
#define KMEANS_H
// Spread memory touched by different threads at least 64B apart which I assume is the cache line size. This should avoid memory write contention.
#define KMEANS_CACHE_LINE_GAP ((64+sizeof(kmeans_state)-1)/sizeof(kmeans_state))
typedef struct {
double a, r, g, b, total;
} kmeans_state;
typedef void (*kmeans_callback)(hist_item *item, float diff);
LIQ_PRIVATE void kmeans_init(const colormap *map, const unsigned int max_threads, kmeans_state state[]);
LIQ_PRIVATE void kmeans_update_color(const f_pixel acolor, const float value, const colormap *map, unsigned int match, const unsigned int thread, kmeans_state average_color[]);
LIQ_PRIVATE void kmeans_finalize(colormap *map, const unsigned int max_threads, const kmeans_state state[]);
LIQ_PRIVATE double kmeans_do_iteration(histogram *hist, colormap *const map, kmeans_callback callback);
#endif

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/*
* https://pngquant.org
*/
#ifndef LIBIMAGEQUANT_H
#define LIBIMAGEQUANT_H
#ifdef IMAGEQUANT_EXPORTS
#define LIQ_EXPORT __declspec(dllexport)
#endif
#ifndef LIQ_EXPORT
#define LIQ_EXPORT extern
#endif
#define LIQ_VERSION 21200
#define LIQ_VERSION_STRING "2.12.2"
#ifndef LIQ_PRIVATE
#if defined(__GNUC__) || defined (__llvm__)
#define LIQ_PRIVATE __attribute__((visibility("hidden")))
#define LIQ_NONNULL __attribute__((nonnull))
#define LIQ_USERESULT __attribute__((warn_unused_result))
#else
#define LIQ_PRIVATE
#define LIQ_NONNULL
#define LIQ_USERESULT
#endif
#endif
#ifdef __cplusplus
extern "C" {
#endif
#include <stddef.h>
typedef struct liq_attr liq_attr;
typedef struct liq_image liq_image;
typedef struct liq_result liq_result;
typedef struct liq_histogram liq_histogram;
typedef struct liq_color {
unsigned char r, g, b, a;
} liq_color;
typedef struct liq_palette {
unsigned int count;
liq_color entries[256];
} liq_palette;
typedef enum liq_error {
LIQ_OK = 0,
LIQ_QUALITY_TOO_LOW = 99,
LIQ_VALUE_OUT_OF_RANGE = 100,
LIQ_OUT_OF_MEMORY,
LIQ_ABORTED,
LIQ_BITMAP_NOT_AVAILABLE,
LIQ_BUFFER_TOO_SMALL,
LIQ_INVALID_POINTER,
LIQ_UNSUPPORTED,
} liq_error;
enum liq_ownership {
LIQ_OWN_ROWS=4,
LIQ_OWN_PIXELS=8,
LIQ_COPY_PIXELS=16,
};
typedef struct liq_histogram_entry {
liq_color color;
unsigned int count;
} liq_histogram_entry;
LIQ_EXPORT LIQ_USERESULT liq_attr* liq_attr_create(void);
LIQ_EXPORT LIQ_USERESULT liq_attr* liq_attr_create_with_allocator(void* (*malloc)(size_t), void (*free)(void*));
LIQ_EXPORT LIQ_USERESULT liq_attr* liq_attr_copy(const liq_attr *orig) LIQ_NONNULL;
LIQ_EXPORT void liq_attr_destroy(liq_attr *attr) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT liq_histogram* liq_histogram_create(const liq_attr* attr);
LIQ_EXPORT liq_error liq_histogram_add_image(liq_histogram *hist, const liq_attr *attr, liq_image* image) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_histogram_add_colors(liq_histogram *hist, const liq_attr *attr, const liq_histogram_entry entries[], int num_entries, double gamma) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_histogram_add_fixed_color(liq_histogram *hist, liq_color color, double gamma) LIQ_NONNULL;
LIQ_EXPORT void liq_histogram_destroy(liq_histogram *hist) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_max_colors(liq_attr* attr, int colors) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_max_colors(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_speed(liq_attr* attr, int speed) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_speed(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_min_opacity(liq_attr* attr, int min) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_min_opacity(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_min_posterization(liq_attr* attr, int bits) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_min_posterization(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_quality(liq_attr* attr, int minimum, int maximum) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_min_quality(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_get_max_quality(const liq_attr* attr) LIQ_NONNULL;
LIQ_EXPORT void liq_set_last_index_transparent(liq_attr* attr, int is_last) LIQ_NONNULL;
typedef void liq_log_callback_function(const liq_attr*, const char *message, void* user_info);
typedef void liq_log_flush_callback_function(const liq_attr*, void* user_info);
LIQ_EXPORT void liq_set_log_callback(liq_attr*, liq_log_callback_function*, void* user_info);
LIQ_EXPORT void liq_set_log_flush_callback(liq_attr*, liq_log_flush_callback_function*, void* user_info);
typedef int liq_progress_callback_function(float progress_percent, void* user_info);
LIQ_EXPORT void liq_attr_set_progress_callback(liq_attr*, liq_progress_callback_function*, void* user_info);
LIQ_EXPORT void liq_result_set_progress_callback(liq_result*, liq_progress_callback_function*, void* user_info);
// The rows and their data are not modified. The type of `rows` is non-const only due to a bug in C's typesystem design.
LIQ_EXPORT LIQ_USERESULT liq_image *liq_image_create_rgba_rows(const liq_attr *attr, void *const rows[], int width, int height, double gamma) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT liq_image *liq_image_create_rgba(const liq_attr *attr, const void *bitmap, int width, int height, double gamma) LIQ_NONNULL;
typedef void liq_image_get_rgba_row_callback(liq_color row_out[], int row, int width, void* user_info);
LIQ_EXPORT LIQ_USERESULT liq_image *liq_image_create_custom(const liq_attr *attr, liq_image_get_rgba_row_callback *row_callback, void* user_info, int width, int height, double gamma);
LIQ_EXPORT liq_error liq_image_set_memory_ownership(liq_image *image, int ownership_flags) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_image_set_background(liq_image *img, liq_image *background_image) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_image_set_importance_map(liq_image *img, unsigned char buffer[], size_t buffer_size, enum liq_ownership memory_handling) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_image_add_fixed_color(liq_image *img, liq_color color) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_image_get_width(const liq_image *img) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT int liq_image_get_height(const liq_image *img) LIQ_NONNULL;
LIQ_EXPORT void liq_image_destroy(liq_image *img) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT liq_error liq_histogram_quantize(liq_histogram *const input_hist, liq_attr *const options, liq_result **result_output) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT liq_error liq_image_quantize(liq_image *const input_image, liq_attr *const options, liq_result **result_output) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_dithering_level(liq_result *res, float dither_level) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_set_output_gamma(liq_result* res, double gamma) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT double liq_get_output_gamma(const liq_result *result) LIQ_NONNULL;
LIQ_EXPORT LIQ_USERESULT const liq_palette *liq_get_palette(liq_result *result) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_write_remapped_image(liq_result *result, liq_image *input_image, void *buffer, size_t buffer_size) LIQ_NONNULL;
LIQ_EXPORT liq_error liq_write_remapped_image_rows(liq_result *result, liq_image *input_image, unsigned char **row_pointers) LIQ_NONNULL;
LIQ_EXPORT double liq_get_quantization_error(const liq_result *result) LIQ_NONNULL;
LIQ_EXPORT int liq_get_quantization_quality(const liq_result *result) LIQ_NONNULL;
LIQ_EXPORT double liq_get_remapping_error(const liq_result *result) LIQ_NONNULL;
LIQ_EXPORT int liq_get_remapping_quality(const liq_result *result) LIQ_NONNULL;
LIQ_EXPORT void liq_result_destroy(liq_result *) LIQ_NONNULL;
LIQ_EXPORT int liq_version(void);
// Deprecated
LIQ_EXPORT LIQ_USERESULT liq_result *liq_quantize_image(liq_attr *options, liq_image *input_image) LIQ_NONNULL;
#ifdef __cplusplus
}
#endif
#endif

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@ -1,469 +0,0 @@
/*
** © 2009-2018 by Kornel Lesiński.
** © 1989, 1991 by Jef Poskanzer.
** © 1997, 2000, 2002 by Greg Roelofs; based on an idea by Stefan Schneider.
**
** See COPYRIGHT file for license.
*/
#include <stdlib.h>
#include <stddef.h>
#include "libimagequant.h"
#include "pam.h"
#include "mediancut.h"
#define index_of_channel(ch) (offsetof(f_pixel,ch)/sizeof(float))
static f_pixel averagepixels(unsigned int clrs, const hist_item achv[]);
struct box {
f_pixel color;
f_pixel variance;
double sum, total_error, max_error;
unsigned int ind;
unsigned int colors;
};
ALWAYS_INLINE static double variance_diff(double val, const double good_enough);
inline static double variance_diff(double val, const double good_enough)
{
val *= val;
if (val < good_enough*good_enough) return val*0.25;
return val;
}
/** Weighted per-channel variance of the box. It's used to decide which channel to split by */
static f_pixel box_variance(const hist_item achv[], const struct box *box)
{
f_pixel mean = box->color;
double variancea=0, variancer=0, varianceg=0, varianceb=0;
for(unsigned int i = 0; i < box->colors; ++i) {
const f_pixel px = achv[box->ind + i].acolor;
double weight = achv[box->ind + i].adjusted_weight;
variancea += variance_diff(mean.a - px.a, 2.0/256.0)*weight;
variancer += variance_diff(mean.r - px.r, 1.0/256.0)*weight;
varianceg += variance_diff(mean.g - px.g, 1.0/256.0)*weight;
varianceb += variance_diff(mean.b - px.b, 1.0/256.0)*weight;
}
return (f_pixel){
.a = variancea*(4.0/16.0),
.r = variancer*(7.0/16.0),
.g = varianceg*(9.0/16.0),
.b = varianceb*(5.0/16.0),
};
}
static double box_max_error(const hist_item achv[], const struct box *box)
{
f_pixel mean = box->color;
double max_error = 0;
for(unsigned int i = 0; i < box->colors; ++i) {
const double diff = colordifference(mean, achv[box->ind + i].acolor);
if (diff > max_error) {
max_error = diff;
}
}
return max_error;
}
ALWAYS_INLINE static double color_weight(f_pixel median, hist_item h);
static inline void hist_item_swap(hist_item *l, hist_item *r)
{
if (l != r) {
hist_item t = *l;
*l = *r;
*r = t;
}
}
ALWAYS_INLINE static unsigned int qsort_pivot(const hist_item *const base, const unsigned int len);
inline static unsigned int qsort_pivot(const hist_item *const base, const unsigned int len)
{
if (len < 32) {
return len/2;
}
const unsigned int aidx=8, bidx=len/2, cidx=len-1;
const unsigned int a=base[aidx].tmp.sort_value, b=base[bidx].tmp.sort_value, c=base[cidx].tmp.sort_value;
return (a < b) ? ((b < c) ? bidx : ((a < c) ? cidx : aidx ))
: ((b > c) ? bidx : ((a < c) ? aidx : cidx ));
}
ALWAYS_INLINE static unsigned int qsort_partition(hist_item *const base, const unsigned int len);
inline static unsigned int qsort_partition(hist_item *const base, const unsigned int len)
{
unsigned int l = 1, r = len;
if (len >= 8) {
hist_item_swap(&base[0], &base[qsort_pivot(base,len)]);
}
const unsigned int pivot_value = base[0].tmp.sort_value;
while (l < r) {
if (base[l].tmp.sort_value >= pivot_value) {
l++;
} else {
while(l < --r && base[r].tmp.sort_value <= pivot_value) {}
hist_item_swap(&base[l], &base[r]);
}
}
l--;
hist_item_swap(&base[0], &base[l]);
return l;
}
/** quick select algorithm */
static void hist_item_sort_range(hist_item base[], unsigned int len, unsigned int sort_start)
{
for(;;) {
const unsigned int l = qsort_partition(base, len), r = l+1;
if (l > 0 && sort_start < l) {
len = l;
}
else if (r < len && sort_start > r) {
base += r; len -= r; sort_start -= r;
}
else break;
}
}
/** sorts array to make sum of weights lower than halfvar one side, returns edge between <halfvar and >halfvar parts of the set */
static hist_item *hist_item_sort_halfvar(hist_item base[], unsigned int len, double *const lowervar, const double halfvar)
{
do {
const unsigned int l = qsort_partition(base, len), r = l+1;
// check if sum of left side is smaller than half,
// if it is, then it doesn't need to be sorted
unsigned int t = 0; double tmpsum = *lowervar;
while (t <= l && tmpsum < halfvar) tmpsum += base[t++].color_weight;
if (tmpsum < halfvar) {
*lowervar = tmpsum;
} else {
if (l > 0) {
hist_item *res = hist_item_sort_halfvar(base, l, lowervar, halfvar);
if (res) return res;
} else {
// End of left recursion. This will be executed in order from the first element.
*lowervar += base[0].color_weight;
if (*lowervar > halfvar) return &base[0];
}
}
if (len > r) {
base += r; len -= r; // tail-recursive "call"
} else {
*lowervar += base[r].color_weight;
return (*lowervar > halfvar) ? &base[r] : NULL;
}
} while(1);
}
static f_pixel get_median(const struct box *b, hist_item achv[]);
typedef struct {
unsigned int chan; float variance;
} channelvariance;
static int comparevariance(const void *ch1, const void *ch2)
{
return ((const channelvariance*)ch1)->variance > ((const channelvariance*)ch2)->variance ? -1 :
(((const channelvariance*)ch1)->variance < ((const channelvariance*)ch2)->variance ? 1 : 0);
}
/** Finds which channels need to be sorted first and preproceses achv for fast sort */
static double prepare_sort(struct box *b, hist_item achv[])
{
/*
** Sort dimensions by their variance, and then sort colors first by dimension with highest variance
*/
channelvariance channels[4] = {
{index_of_channel(a), b->variance.a},
{index_of_channel(r), b->variance.r},
{index_of_channel(g), b->variance.g},
{index_of_channel(b), b->variance.b},
};
qsort(channels, 4, sizeof(channels[0]), comparevariance);
const unsigned int ind1 = b->ind;
const unsigned int colors = b->colors;
#pragma omp parallel for if (colors > 25000) \
schedule(static) default(none) shared(achv, channels)
for(unsigned int i=0; i < colors; i++) {
const float *chans = (const float *)&achv[ind1 + i].acolor;
// Only the first channel really matters. When trying median cut many times
// with different histogram weights, I don't want sort randomness to influence outcome.
achv[ind1 + i].tmp.sort_value = ((unsigned int)(chans[channels[0].chan]*65535.0)<<16) |
(unsigned int)((chans[channels[2].chan] + chans[channels[1].chan]/2.0 + chans[channels[3].chan]/4.0)*65535.0);
}
const f_pixel median = get_median(b, achv);
// box will be split to make color_weight of each side even
const unsigned int ind = b->ind, end = ind+b->colors;
double totalvar = 0;
#pragma omp parallel for if (end - ind > 15000) \
schedule(static) default(shared) reduction(+:totalvar)
for(unsigned int j=ind; j < end; j++) totalvar += (achv[j].color_weight = color_weight(median, achv[j]));
return totalvar / 2.0;
}
/** finds median in unsorted set by sorting only minimum required */
static f_pixel get_median(const struct box *b, hist_item achv[])
{
const unsigned int median_start = (b->colors-1)/2;
hist_item_sort_range(&(achv[b->ind]), b->colors,
median_start);
if (b->colors&1) return achv[b->ind + median_start].acolor;
// technically the second color is not guaranteed to be sorted correctly
// but most of the time it is good enough to be useful
return averagepixels(2, &achv[b->ind + median_start]);
}
/*
** Find the best splittable box. -1 if no boxes are splittable.
*/
static int best_splittable_box(struct box bv[], unsigned int boxes, const double max_mse)
{
int bi=-1; double maxsum=0;
for(unsigned int i=0; i < boxes; i++) {
if (bv[i].colors < 2) {
continue;
}
// looks only at max variance, because it's only going to split by it
const double cv = MAX(bv[i].variance.r, MAX(bv[i].variance.g,bv[i].variance.b));
double thissum = bv[i].sum * MAX(bv[i].variance.a, cv);
if (bv[i].max_error > max_mse) {
thissum = thissum* bv[i].max_error/max_mse;
}
if (thissum > maxsum) {
maxsum = thissum;
bi = i;
}
}
return bi;
}
inline static double color_weight(f_pixel median, hist_item h)
{
float diff = colordifference(median, h.acolor);
return sqrt(diff) * (sqrt(1.0+h.adjusted_weight)-1.0);
}
static void set_colormap_from_boxes(colormap *map, struct box bv[], unsigned int boxes, hist_item *achv);
static void adjust_histogram(hist_item *achv, const struct box bv[], unsigned int boxes);
static double box_error(const struct box *box, const hist_item achv[])
{
f_pixel avg = box->color;
double total_error=0;
for (unsigned int i = 0; i < box->colors; ++i) {
total_error += colordifference(avg, achv[box->ind + i].acolor) * achv[box->ind + i].perceptual_weight;
}
return total_error;
}
static bool total_box_error_below_target(double target_mse, struct box bv[], unsigned int boxes, const histogram *hist)
{
target_mse *= hist->total_perceptual_weight;
double total_error=0;
for(unsigned int i=0; i < boxes; i++) {
// error is (re)calculated lazily
if (bv[i].total_error >= 0) {
total_error += bv[i].total_error;
}
if (total_error > target_mse) return false;
}
for(unsigned int i=0; i < boxes; i++) {
if (bv[i].total_error < 0) {
bv[i].total_error = box_error(&bv[i], hist->achv);
total_error += bv[i].total_error;
}
if (total_error > target_mse) return false;
}
return true;
}
static void box_init(struct box *box, const hist_item *achv, const unsigned int ind, const unsigned int colors, const double sum) {
box->ind = ind;
box->colors = colors;
box->sum = sum;
box->total_error = -1;
box->color = averagepixels(colors, &achv[ind]);
#pragma omp task if (colors > 5000)
box->variance = box_variance(achv, box);
#pragma omp task if (colors > 8000)
box->max_error = box_max_error(achv, box);
}
/*
** Here is the fun part, the median-cut colormap generator. This is based
** on Paul Heckbert's paper, "Color Image Quantization for Frame Buffer
** Display," SIGGRAPH 1982 Proceedings, page 297.
*/
LIQ_PRIVATE colormap *mediancut(histogram *hist, unsigned int newcolors, const double target_mse, const double max_mse, void* (*malloc)(size_t), void (*free)(void*))
{
hist_item *achv = hist->achv;
LIQ_ARRAY(struct box, bv, newcolors);
unsigned int boxes = 1;
/*
** Set up the initial box.
*/
#pragma omp parallel
#pragma omp single
{
double sum = 0;
for(unsigned int i=0; i < hist->size; i++) {
sum += achv[i].adjusted_weight;
}
#pragma omp taskgroup
{
box_init(&bv[0], achv, 0, hist->size, sum);
}
/*
** Main loop: split boxes until we have enough.
*/
while (boxes < newcolors) {
// first splits boxes that exceed quality limit (to have colors for things like odd green pixel),
// later raises the limit to allow large smooth areas/gradients get colors.
const double current_max_mse = max_mse + (boxes/(double)newcolors)*16.0*max_mse;
const int bi = best_splittable_box(bv, boxes, current_max_mse);
if (bi < 0) {
break; /* ran out of colors! */
}
unsigned int indx = bv[bi].ind;
unsigned int clrs = bv[bi].colors;
/*
Classic implementation tries to get even number of colors or pixels in each subdivision.
Here, instead of popularity I use (sqrt(popularity)*variance) metric.
Each subdivision balances number of pixels (popular colors) and low variance -
boxes can be large if they have similar colors. Later boxes with high variance
will be more likely to be split.
Median used as expected value gives much better results than mean.
*/
const double halfvar = prepare_sort(&bv[bi], achv);
double lowervar=0;
// hist_item_sort_halfvar sorts and sums lowervar at the same time
// returns item to break at …minus one, which does smell like an off-by-one error.
hist_item *break_p = hist_item_sort_halfvar(&achv[indx], clrs, &lowervar, halfvar);
unsigned int break_at = MIN(clrs-1, break_p - &achv[indx] + 1);
/*
** Split the box.
*/
double sm = bv[bi].sum;
double lowersum = 0;
for(unsigned int i=0; i < break_at; i++) lowersum += achv[indx + i].adjusted_weight;
#pragma omp taskgroup
{
box_init(&bv[bi], achv, indx, break_at, lowersum);
box_init(&bv[boxes], achv, indx + break_at, clrs - break_at, sm - lowersum);
}
++boxes;
if (total_box_error_below_target(target_mse, bv, boxes, hist)) {
break;
}
}
}
colormap *map = pam_colormap(boxes, malloc, free);
set_colormap_from_boxes(map, bv, boxes, achv);
adjust_histogram(achv, bv, boxes);
return map;
}
static void set_colormap_from_boxes(colormap *map, struct box* bv, unsigned int boxes, hist_item *achv)
{
/*
** Ok, we've got enough boxes. Now choose a representative color for
** each box. There are a number of possible ways to make this choice.
** One would be to choose the center of the box; this ignores any structure
** within the boxes. Another method would be to average all the colors in
** the box - this is the method specified in Heckbert's paper.
*/
for(unsigned int bi = 0; bi < boxes; ++bi) {
map->palette[bi].acolor = bv[bi].color;
/* store total color popularity (perceptual_weight is approximation of it) */
map->palette[bi].popularity = 0;
for(unsigned int i=bv[bi].ind; i < bv[bi].ind+bv[bi].colors; i++) {
map->palette[bi].popularity += achv[i].perceptual_weight;
}
}
}
/* increase histogram popularity by difference from the final color (this is used as part of feedback loop) */
static void adjust_histogram(hist_item *achv, const struct box* bv, unsigned int boxes)
{
for(unsigned int bi = 0; bi < boxes; ++bi) {
for(unsigned int i=bv[bi].ind; i < bv[bi].ind+bv[bi].colors; i++) {
achv[i].tmp.likely_colormap_index = bi;
}
}
}
static f_pixel averagepixels(unsigned int clrs, const hist_item achv[])
{
double r = 0, g = 0, b = 0, a = 0, sum = 0;
#pragma omp parallel for if (clrs > 25000) \
schedule(static) default(shared) reduction(+:a) reduction(+:r) reduction(+:g) reduction(+:b) reduction(+:sum)
for(unsigned int i = 0; i < clrs; i++) {
const f_pixel px = achv[i].acolor;
const double weight = achv[i].adjusted_weight;
sum += weight;
a += px.a * weight;
r += px.r * weight;
g += px.g * weight;
b += px.b * weight;
}
if (sum) {
a /= sum;
r /= sum;
g /= sum;
b /= sum;
}
assert(!isnan(r) && !isnan(g) && !isnan(b) && !isnan(a));
return (f_pixel){.r=r, .g=g, .b=b, .a=a};
}

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LIQ_PRIVATE colormap *mediancut(histogram *hist, unsigned int newcolors, const double target_mse, const double max_mse, void* (*malloc)(size_t), void (*free)(void*));

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/*
** © 2009-2017 by Kornel Lesiński.
** © 1989, 1991 by Jef Poskanzer.
** © 1997, 2000, 2002 by Greg Roelofs; based on an idea by Stefan Schneider.
**
** See COPYRIGHT file for license.
*/
#include "libimagequant.h"
#include "mempool.h"
#include <stdlib.h>
#include <stdint.h>
#include <assert.h>
#define ALIGN_MASK 15UL
#define MEMPOOL_RESERVED ((sizeof(struct mempool)+ALIGN_MASK) & ~ALIGN_MASK)
struct mempool {
unsigned int used, size;
void* (*malloc)(size_t);
void (*free)(void*);
struct mempool *next;
};
LIQ_PRIVATE void* mempool_create(mempoolptr *mptr, const unsigned int size, unsigned int max_size, void* (*malloc)(size_t), void (*free)(void*))
{
if (*mptr && ((*mptr)->used+size) <= (*mptr)->size) {
unsigned int prevused = (*mptr)->used;
(*mptr)->used += (size+15UL) & ~0xFUL;
return ((char*)(*mptr)) + prevused;
}
mempoolptr old = *mptr;
if (!max_size) max_size = (1<<17);
max_size = size+ALIGN_MASK > max_size ? size+ALIGN_MASK : max_size;
*mptr = malloc(MEMPOOL_RESERVED + max_size);
if (!*mptr) return NULL;
**mptr = (struct mempool){
.malloc = malloc,
.free = free,
.size = MEMPOOL_RESERVED + max_size,
.used = sizeof(struct mempool),
.next = old,
};
uintptr_t mptr_used_start = (uintptr_t)(*mptr) + (*mptr)->used;
(*mptr)->used += (ALIGN_MASK + 1 - (mptr_used_start & ALIGN_MASK)) & ALIGN_MASK; // reserve bytes required to make subsequent allocations aligned
assert(!(((uintptr_t)(*mptr) + (*mptr)->used) & ALIGN_MASK));
return mempool_alloc(mptr, size, size);
}
LIQ_PRIVATE void* mempool_alloc(mempoolptr *mptr, const unsigned int size, const unsigned int max_size)
{
if (((*mptr)->used+size) <= (*mptr)->size) {
unsigned int prevused = (*mptr)->used;
(*mptr)->used += (size + ALIGN_MASK) & ~ALIGN_MASK;
return ((char*)(*mptr)) + prevused;
}
return mempool_create(mptr, size, max_size, (*mptr)->malloc, (*mptr)->free);
}
LIQ_PRIVATE void mempool_destroy(mempoolptr m)
{
while (m) {
mempoolptr next = m->next;
m->free(m);
m = next;
}
}

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#ifndef MEMPOOL_H
#define MEMPOOL_H
#include <stddef.h>
struct mempool;
typedef struct mempool *mempoolptr;
LIQ_PRIVATE void* mempool_create(mempoolptr *mptr, const unsigned int size, unsigned int capacity, void* (*malloc)(size_t), void (*free)(void*));
LIQ_PRIVATE void* mempool_alloc(mempoolptr *mptr, const unsigned int size, const unsigned int capacity);
LIQ_PRIVATE void mempool_destroy(mempoolptr m);
#endif

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/*
** © 2009-2015 by Kornel Lesiński.
** © 1989, 1991 by Jef Poskanzer.
** © 1997, 2000, 2002 by Greg Roelofs; based on an idea by Stefan Schneider.
**
** See COPYRIGHT file for license.
*/
#include "libimagequant.h"
#include "pam.h"
#include "nearest.h"
#include "mempool.h"
#include <stdlib.h>
typedef struct vp_sort_tmp {
float distance_squared;
unsigned int idx;
} vp_sort_tmp;
typedef struct vp_search_tmp {
float distance;
unsigned int idx;
int exclude;
} vp_search_tmp;
typedef struct vp_node {
struct vp_node *near, *far;
f_pixel vantage_point;
float radius;
unsigned int idx;
} vp_node;
struct nearest_map {
vp_node *root;
const colormap_item *palette;
float nearest_other_color_dist[256];
mempoolptr mempool;
};
static void vp_search_node(const vp_node *node, const f_pixel *const needle, vp_search_tmp *const best_candidate);
static int vp_compare_distance(const void *ap, const void *bp) {
float a = ((const vp_sort_tmp*)ap)->distance_squared;
float b = ((const vp_sort_tmp*)bp)->distance_squared;
return a > b ? 1 : -1;
}
static void vp_sort_indexes_by_distance(const f_pixel vantage_point, vp_sort_tmp indexes[], int num_indexes, const colormap_item items[]) {
for(int i=0; i < num_indexes; i++) {
indexes[i].distance_squared = colordifference(vantage_point, items[indexes[i].idx].acolor);
}
qsort(indexes, num_indexes, sizeof(indexes[0]), vp_compare_distance);
}
/*
* Usually it should pick farthest point, but picking most popular point seems to make search quicker anyway
*/
static int vp_find_best_vantage_point_index(vp_sort_tmp indexes[], int num_indexes, const colormap_item items[]) {
int best = 0;
float best_popularity = items[indexes[0].idx].popularity;
for(int i = 1; i < num_indexes; i++) {
if (items[indexes[i].idx].popularity > best_popularity) {
best_popularity = items[indexes[i].idx].popularity;
best = i;
}
}
return best;
}
static vp_node *vp_create_node(mempoolptr *m, vp_sort_tmp indexes[], int num_indexes, const colormap_item items[]) {
if (num_indexes <= 0) {
return NULL;
}
vp_node *node = mempool_alloc(m, sizeof(node[0]), 0);
if (num_indexes == 1) {
*node = (vp_node){
.vantage_point = items[indexes[0].idx].acolor,
.idx = indexes[0].idx,
.radius = MAX_DIFF,
};
return node;
}
const int ref = vp_find_best_vantage_point_index(indexes, num_indexes, items);
const int ref_idx = indexes[ref].idx;
// Removes the `ref_idx` item from remaining items, because it's included in the current node
num_indexes -= 1;
indexes[ref] = indexes[num_indexes];
vp_sort_indexes_by_distance(items[ref_idx].acolor, indexes, num_indexes, items);
// Remaining items are split by the median distance
const int half_idx = num_indexes/2;
*node = (vp_node){
.vantage_point = items[ref_idx].acolor,
.idx = ref_idx,
.radius = sqrtf(indexes[half_idx].distance_squared),
};
node->near = vp_create_node(m, indexes, half_idx, items);
node->far = vp_create_node(m, &indexes[half_idx], num_indexes - half_idx, items);
return node;
}
LIQ_PRIVATE struct nearest_map *nearest_init(const colormap *map) {
mempoolptr m = NULL;
struct nearest_map *handle = mempool_create(&m, sizeof(handle[0]), sizeof(handle[0]) + sizeof(vp_node)*map->colors+16, map->malloc, map->free);
LIQ_ARRAY(vp_sort_tmp, indexes, map->colors);
for(unsigned int i=0; i < map->colors; i++) {
indexes[i].idx = i;
}
vp_node *root = vp_create_node(&m, indexes, map->colors, map->palette);
*handle = (struct nearest_map){
.root = root,
.palette = map->palette,
.mempool = m,
};
for(unsigned int i=0; i < map->colors; i++) {
vp_search_tmp best = {
.distance = MAX_DIFF,
.exclude = i,
};
vp_search_node(root, &map->palette[i].acolor, &best);
handle->nearest_other_color_dist[i] = best.distance * best.distance / 4.0; // half of squared distance
}
return handle;
}
static void vp_search_node(const vp_node *node, const f_pixel *const needle, vp_search_tmp *const best_candidate) {
do {
const float distance = sqrtf(colordifference(node->vantage_point, *needle));
if (distance < best_candidate->distance && best_candidate->exclude != node->idx) {
best_candidate->distance = distance;
best_candidate->idx = node->idx;
}
// Recurse towards most likely candidate first to narrow best candidate's distance as soon as possible
if (distance < node->radius) {
if (node->near) {
vp_search_node(node->near, needle, best_candidate);
}
// The best node (final answer) may be just ouside the radius, but not farther than
// the best distance we know so far. The vp_search_node above should have narrowed
// best_candidate->distance, so this path is rarely taken.
if (node->far && distance >= node->radius - best_candidate->distance) {
node = node->far; // Fast tail recursion
} else {
break;
}
} else {
if (node->far) {
vp_search_node(node->far, needle, best_candidate);
}
if (node->near && distance <= node->radius + best_candidate->distance) {
node = node->near; // Fast tail recursion
} else {
break;
}
}
} while(true);
}
LIQ_PRIVATE unsigned int nearest_search(const struct nearest_map *handle, const f_pixel *px, const int likely_colormap_index, float *diff) {
const float guess_diff = colordifference(handle->palette[likely_colormap_index].acolor, *px);
if (guess_diff < handle->nearest_other_color_dist[likely_colormap_index]) {
if (diff) *diff = guess_diff;
return likely_colormap_index;
}
vp_search_tmp best_candidate = {
.distance = sqrtf(guess_diff),
.idx = likely_colormap_index,
.exclude = -1,
};
vp_search_node(handle->root, px, &best_candidate);
if (diff) {
*diff = best_candidate.distance * best_candidate.distance;
}
return best_candidate.idx;
}
LIQ_PRIVATE void nearest_free(struct nearest_map *centroids)
{
mempool_destroy(centroids->mempool);
}

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//
// nearest.h
// pngquant
//
struct nearest_map;
LIQ_PRIVATE struct nearest_map *nearest_init(const colormap *palette);
LIQ_PRIVATE unsigned int nearest_search(const struct nearest_map *map, const f_pixel *px, const int palette_index_guess, float *diff);
LIQ_PRIVATE void nearest_free(struct nearest_map *map);

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/* pam.c - pam (portable alpha map) utility library
**
** © 2009-2017 by Kornel Lesiński.
** © 1989, 1991 by Jef Poskanzer.
** © 1997, 2000, 2002 by Greg Roelofs; based on an idea by Stefan Schneider.
**
** See COPYRIGHT file for license.
*/
#include <stdlib.h>
#include <string.h>
#include "libimagequant.h"
#include "pam.h"
#include "mempool.h"
LIQ_PRIVATE bool pam_computeacolorhash(struct acolorhash_table *acht, const rgba_pixel *const pixels[], unsigned int cols, unsigned int rows, const unsigned char *importance_map)
{
const unsigned int ignorebits = acht->ignorebits;
const unsigned int channel_mask = 255U>>ignorebits<<ignorebits;
const unsigned int channel_hmask = (255U>>ignorebits) ^ 0xFFU;
const unsigned int posterize_mask = channel_mask << 24 | channel_mask << 16 | channel_mask << 8 | channel_mask;
const unsigned int posterize_high_mask = channel_hmask << 24 | channel_hmask << 16 | channel_hmask << 8 | channel_hmask;
const unsigned int hash_size = acht->hash_size;
/* Go through the entire image, building a hash table of colors. */
for(unsigned int row = 0; row < rows; ++row) {
for(unsigned int col = 0; col < cols; ++col) {
unsigned int boost;
// RGBA color is casted to long for easier hasing/comparisons
union rgba_as_int px = {pixels[row][col]};
unsigned int hash;
if (!px.rgba.a) {
// "dirty alpha" has different RGBA values that end up being the same fully transparent color
px.l=0; hash=0;
boost = 2000;
if (importance_map) {
importance_map++;
}
} else {
// mask posterizes all 4 channels in one go
px.l = (px.l & posterize_mask) | ((px.l & posterize_high_mask) >> (8-ignorebits));
// fancier hashing algorithms didn't improve much
hash = px.l % hash_size;
if (importance_map) {
boost = *importance_map++;
} else {
boost = 255;
}
}
if (!pam_add_to_hash(acht, hash, boost, px, row, rows)) {
return false;
}
}
}
acht->cols = cols;
acht->rows += rows;
return true;
}
LIQ_PRIVATE bool pam_add_to_hash(struct acolorhash_table *acht, unsigned int hash, unsigned int boost, union rgba_as_int px, unsigned int row, unsigned int rows)
{
/* head of the hash function stores first 2 colors inline (achl->used = 1..2),
to reduce number of allocations of achl->other_items.
*/
struct acolorhist_arr_head *achl = &acht->buckets[hash];
if (achl->inline1.color.l == px.l && achl->used) {
achl->inline1.perceptual_weight += boost;
return true;
}
if (achl->used) {
if (achl->used > 1) {
if (achl->inline2.color.l == px.l) {
achl->inline2.perceptual_weight += boost;
return true;
}
// other items are stored as an array (which gets reallocated if needed)
struct acolorhist_arr_item *other_items = achl->other_items;
unsigned int i = 0;
for (; i < achl->used-2; i++) {
if (other_items[i].color.l == px.l) {
other_items[i].perceptual_weight += boost;
return true;
}
}
// the array was allocated with spare items
if (i < achl->capacity) {
other_items[i] = (struct acolorhist_arr_item){
.color = px,
.perceptual_weight = boost,
};
achl->used++;
++acht->colors;
return true;
}
if (++acht->colors > acht->maxcolors) {
return false;
}
struct acolorhist_arr_item *new_items;
unsigned int capacity;
if (!other_items) { // there was no array previously, alloc "small" array
capacity = 8;
if (acht->freestackp <= 0) {
// estimate how many colors are going to be + headroom
const size_t mempool_size = ((acht->rows + rows-row) * 2 * acht->colors / (acht->rows + row + 1) + 1024) * sizeof(struct acolorhist_arr_item);
new_items = mempool_alloc(&acht->mempool, sizeof(struct acolorhist_arr_item)*capacity, mempool_size);
} else {
// freestack stores previously freed (reallocated) arrays that can be reused
// (all pesimistically assumed to be capacity = 8)
new_items = acht->freestack[--acht->freestackp];
}
} else {
const unsigned int stacksize = sizeof(acht->freestack)/sizeof(acht->freestack[0]);
// simply reallocs and copies array to larger capacity
capacity = achl->capacity*2 + 16;
if (acht->freestackp < stacksize-1) {
acht->freestack[acht->freestackp++] = other_items;
}
const size_t mempool_size = ((acht->rows + rows-row) * 2 * acht->colors / (acht->rows + row + 1) + 32*capacity) * sizeof(struct acolorhist_arr_item);
new_items = mempool_alloc(&acht->mempool, sizeof(struct acolorhist_arr_item)*capacity, mempool_size);
if (!new_items) return false;
memcpy(new_items, other_items, sizeof(other_items[0])*achl->capacity);
}
achl->other_items = new_items;
achl->capacity = capacity;
new_items[i] = (struct acolorhist_arr_item){
.color = px,
.perceptual_weight = boost,
};
achl->used++;
} else {
// these are elses for first checks whether first and second inline-stored colors are used
achl->inline2.color.l = px.l;
achl->inline2.perceptual_weight = boost;
achl->used = 2;
++acht->colors;
}
} else {
achl->inline1.color.l = px.l;
achl->inline1.perceptual_weight = boost;
achl->used = 1;
++acht->colors;
}
return true;
}
LIQ_PRIVATE struct acolorhash_table *pam_allocacolorhash(unsigned int maxcolors, unsigned int surface, unsigned int ignorebits, void* (*malloc)(size_t), void (*free)(void*))
{
const size_t estimated_colors = MIN(maxcolors, surface/(ignorebits + (surface > 512*512 ? 6 : 5)));
const size_t hash_size = estimated_colors < 66000 ? 6673 : (estimated_colors < 200000 ? 12011 : 24019);
mempoolptr m = NULL;
const size_t buckets_size = hash_size * sizeof(struct acolorhist_arr_head);
const size_t mempool_size = sizeof(struct acolorhash_table) + buckets_size + estimated_colors * sizeof(struct acolorhist_arr_item);
struct acolorhash_table *t = mempool_create(&m, sizeof(*t) + buckets_size, mempool_size, malloc, free);
if (!t) return NULL;
*t = (struct acolorhash_table){
.mempool = m,
.hash_size = hash_size,
.maxcolors = maxcolors,
.ignorebits = ignorebits,
};
memset(t->buckets, 0, buckets_size);
return t;
}
ALWAYS_INLINE static float pam_add_to_hist(const float *gamma_lut, hist_item *achv, unsigned int *j, const struct acolorhist_arr_item *entry, const float max_perceptual_weight)
{
if (entry->perceptual_weight == 0) {
return 0;
}
const float w = MIN(entry->perceptual_weight/128.f, max_perceptual_weight);
achv[*j].adjusted_weight = achv[*j].perceptual_weight = w;
achv[*j].acolor = rgba_to_f(gamma_lut, entry->color.rgba);
*j += 1;
return w;
}
LIQ_PRIVATE histogram *pam_acolorhashtoacolorhist(const struct acolorhash_table *acht, const double gamma, void* (*malloc)(size_t), void (*free)(void*))
{
histogram *hist = malloc(sizeof(hist[0]));
if (!hist || !acht) return NULL;
*hist = (histogram){
.achv = malloc(MAX(1,acht->colors) * sizeof(hist->achv[0])),
.size = acht->colors,
.free = free,
.ignorebits = acht->ignorebits,
};
if (!hist->achv) return NULL;
float gamma_lut[256];
to_f_set_gamma(gamma_lut, gamma);
/* Limit perceptual weight to 1/10th of the image surface area to prevent
a single color from dominating all others. */
float max_perceptual_weight = 0.1f * acht->cols * acht->rows;
double total_weight = 0;
unsigned int j=0;
for(unsigned int i=0; i < acht->hash_size; ++i) {
const struct acolorhist_arr_head *const achl = &acht->buckets[i];
if (achl->used) {
total_weight += pam_add_to_hist(gamma_lut, hist->achv, &j, &achl->inline1, max_perceptual_weight);
if (achl->used > 1) {
total_weight += pam_add_to_hist(gamma_lut, hist->achv, &j, &achl->inline2, max_perceptual_weight);
for(unsigned int k=0; k < achl->used-2; k++) {
total_weight += pam_add_to_hist(gamma_lut, hist->achv, &j, &achl->other_items[k], max_perceptual_weight);
}
}
}
}
hist->size = j;
hist->total_perceptual_weight = total_weight;
if (!j) {
pam_freeacolorhist(hist);
return NULL;
}
return hist;
}
LIQ_PRIVATE void pam_freeacolorhash(struct acolorhash_table *acht)
{
if (acht) {
mempool_destroy(acht->mempool);
}
}
LIQ_PRIVATE void pam_freeacolorhist(histogram *hist)
{
hist->free(hist->achv);
hist->free(hist);
}
LIQ_PRIVATE colormap *pam_colormap(unsigned int colors, void* (*malloc)(size_t), void (*free)(void*))
{
assert(colors > 0 && colors < 65536);
colormap *map;
const size_t colors_size = colors * sizeof(map->palette[0]);
map = malloc(sizeof(colormap) + colors_size);
if (!map) return NULL;
*map = (colormap){
.malloc = malloc,
.free = free,
.colors = colors,
};
memset(map->palette, 0, colors_size);
return map;
}
LIQ_PRIVATE colormap *pam_duplicate_colormap(colormap *map)
{
colormap *dupe = pam_colormap(map->colors, map->malloc, map->free);
for(unsigned int i=0; i < map->colors; i++) {
dupe->palette[i] = map->palette[i];
}
return dupe;
}
LIQ_PRIVATE void pam_freecolormap(colormap *c)
{
c->free(c);
}
LIQ_PRIVATE void to_f_set_gamma(float gamma_lut[], const double gamma)
{
for(int i=0; i < 256; i++) {
gamma_lut[i] = pow((double)i/255.0, internal_gamma/gamma);
}
}

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/* pam.h - pam (portable alpha map) utility library
**
** Colormap routines.
**
** Copyright (C) 1989, 1991 by Jef Poskanzer.
** Copyright (C) 1997 by Greg Roelofs.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation. This software is provided "as is" without express or
** implied warranty.
*/
#ifndef PAM_H
#define PAM_H
#include <math.h>
#include <assert.h>
#include <stdlib.h>
#include <stdbool.h>
#ifndef MAX
# define MAX(a,b) ((a) > (b)? (a) : (b))
# define MIN(a,b) ((a) < (b)? (a) : (b))
#endif
#define MAX_DIFF 1e20
#ifndef USE_SSE
# if defined(__SSE__) && (defined(__amd64__) || defined(__X86_64__) || defined(_WIN64) || defined(WIN32) || defined(__WIN32__))
# define USE_SSE 1
# else
# define USE_SSE 0
# endif
#endif
#if USE_SSE
# include <xmmintrin.h>
# ifdef _MSC_VER
# include <intrin.h>
# define SSE_ALIGN
# else
# define SSE_ALIGN __attribute__ ((aligned (16)))
# if defined(__i386__) && defined(__PIC__)
# define cpuid(func,ax,bx,cx,dx)\
__asm__ __volatile__ ( \
"push %%ebx\n" \
"cpuid\n" \
"mov %%ebx, %1\n" \
"pop %%ebx\n" \
: "=a" (ax), "=r" (bx), "=c" (cx), "=d" (dx) \
: "a" (func));
# else
# define cpuid(func,ax,bx,cx,dx)\
__asm__ __volatile__ ("cpuid":\
"=a" (ax), "=b" (bx), "=c" (cx), "=d" (dx) : "a" (func));
# endif
#endif
#else
# define SSE_ALIGN
#endif
#ifndef _MSC_VER
#define LIQ_ARRAY(type, var, count) type var[count]
#else
#define LIQ_ARRAY(type, var, count) type* var = (type*)_alloca(sizeof(type)*(count))
#endif
#if defined(__GNUC__) || defined (__llvm__)
#define ALWAYS_INLINE __attribute__((always_inline)) inline
#define NEVER_INLINE __attribute__ ((noinline))
#elif defined(_MSC_VER)
#define inline __inline
#define restrict __restrict
#define ALWAYS_INLINE __forceinline
#define NEVER_INLINE __declspec(noinline)
#else
#define ALWAYS_INLINE inline
#define NEVER_INLINE
#endif
/* from pam.h */
typedef struct {
unsigned char r, g, b, a;
} rgba_pixel;
typedef struct {
float a, r, g, b;
} SSE_ALIGN f_pixel;
static const float internal_gamma = 0.5499f;
LIQ_PRIVATE void to_f_set_gamma(float gamma_lut[], const double gamma);
/**
Converts 8-bit color to internal gamma and premultiplied alpha.
(premultiplied color space is much better for blending of semitransparent colors)
*/
ALWAYS_INLINE static f_pixel rgba_to_f(const float gamma_lut[], const rgba_pixel px);
inline static f_pixel rgba_to_f(const float gamma_lut[], const rgba_pixel px)
{
float a = px.a/255.f;
return (f_pixel) {
.a = a,
.r = gamma_lut[px.r]*a,
.g = gamma_lut[px.g]*a,
.b = gamma_lut[px.b]*a,
};
}
inline static rgba_pixel f_to_rgb(const float gamma, const f_pixel px)
{
if (px.a < 1.f/256.f) {
return (rgba_pixel){0,0,0,0};
}
float r = px.r / px.a,
g = px.g / px.a,
b = px.b / px.a,
a = px.a;
r = powf(r, gamma/internal_gamma);
g = powf(g, gamma/internal_gamma);
b = powf(b, gamma/internal_gamma);
// 256, because numbers are in range 1..255.9999… rounded down
r *= 256.f;
g *= 256.f;
b *= 256.f;
a *= 256.f;
return (rgba_pixel){
.r = r>=255.f ? 255 : r,
.g = g>=255.f ? 255 : g,
.b = b>=255.f ? 255 : b,
.a = a>=255.f ? 255 : a,
};
}
ALWAYS_INLINE static double colordifference_ch(const double x, const double y, const double alphas);
inline static double colordifference_ch(const double x, const double y, const double alphas)
{
// maximum of channel blended on white, and blended on black
// premultiplied alpha and backgrounds 0/1 shorten the formula
const double black = x-y, white = black+alphas;
return MAX(black*black, white*white);
}
ALWAYS_INLINE static float colordifference_stdc(const f_pixel px, const f_pixel py);
inline static float colordifference_stdc(const f_pixel px, const f_pixel py)
{
// px_b.rgb = px.rgb + 0*(1-px.a) // blend px on black
// px_b.a = px.a + 1*(1-px.a)
// px_w.rgb = px.rgb + 1*(1-px.a) // blend px on white
// px_w.a = px.a + 1*(1-px.a)
// px_b.rgb = px.rgb // difference same as in opaque RGB
// px_b.a = 1
// px_w.rgb = px.rgb - px.a // difference simplifies to formula below
// px_w.a = 1
// (px.rgb - px.a) - (py.rgb - py.a)
// (px.rgb - py.rgb) + (py.a - px.a)
const double alphas = py.a-px.a;
return colordifference_ch(px.r, py.r, alphas) +
colordifference_ch(px.g, py.g, alphas) +
colordifference_ch(px.b, py.b, alphas);
}
ALWAYS_INLINE static float colordifference(f_pixel px, f_pixel py);
inline static float colordifference(f_pixel px, f_pixel py)
{
#if USE_SSE
const __m128 vpx = _mm_load_ps((const float*)&px);
const __m128 vpy = _mm_load_ps((const float*)&py);
// y.a - x.a
__m128 alphas = _mm_sub_ss(vpy, vpx);
alphas = _mm_shuffle_ps(alphas,alphas,0); // copy first to all four
__m128 onblack = _mm_sub_ps(vpx, vpy); // x - y
__m128 onwhite = _mm_add_ps(onblack, alphas); // x - y + (y.a - x.a)
onblack = _mm_mul_ps(onblack, onblack);
onwhite = _mm_mul_ps(onwhite, onwhite);
const __m128 max = _mm_max_ps(onwhite, onblack);
// add rgb, not a
const __m128 maxhl = _mm_movehl_ps(max, max);
const __m128 tmp = _mm_add_ps(max, maxhl);
const __m128 sum = _mm_add_ss(maxhl, _mm_shuffle_ps(tmp, tmp, 1));
const float res = _mm_cvtss_f32(sum);
assert(fabs(res - colordifference_stdc(px,py)) < 0.001);
return res;
#else
return colordifference_stdc(px,py);
#endif
}
/* from pamcmap.h */
union rgba_as_int {
rgba_pixel rgba;
unsigned int l;
};
typedef struct {
f_pixel acolor;
float adjusted_weight, // perceptual weight changed to tweak how mediancut selects colors
perceptual_weight; // number of pixels weighted by importance of different areas of the picture
float color_weight; // these two change every time histogram subset is sorted
union {
unsigned int sort_value;
unsigned char likely_colormap_index;
} tmp;
} hist_item;
typedef struct {
hist_item *achv;
void (*free)(void*);
double total_perceptual_weight;
unsigned int size;
unsigned int ignorebits;
} histogram;
typedef struct {
f_pixel acolor;
float popularity;
bool fixed; // if true it's user-supplied and must not be changed (e.g in K-Means iteration)
} colormap_item;
typedef struct colormap {
unsigned int colors;
void* (*malloc)(size_t);
void (*free)(void*);
colormap_item palette[];
} colormap;
struct acolorhist_arr_item {
union rgba_as_int color;
unsigned int perceptual_weight;
};
struct acolorhist_arr_head {
struct acolorhist_arr_item inline1, inline2;
unsigned int used, capacity;
struct acolorhist_arr_item *other_items;
};
struct acolorhash_table {
struct mempool *mempool;
unsigned int ignorebits, maxcolors, colors, cols, rows;
unsigned int hash_size;
unsigned int freestackp;
struct acolorhist_arr_item *freestack[512];
struct acolorhist_arr_head buckets[];
};
LIQ_PRIVATE void pam_freeacolorhash(struct acolorhash_table *acht);
LIQ_PRIVATE struct acolorhash_table *pam_allocacolorhash(unsigned int maxcolors, unsigned int surface, unsigned int ignorebits, void* (*malloc)(size_t), void (*free)(void*));
LIQ_PRIVATE histogram *pam_acolorhashtoacolorhist(const struct acolorhash_table *acht, const double gamma, void* (*malloc)(size_t), void (*free)(void*));
LIQ_PRIVATE bool pam_computeacolorhash(struct acolorhash_table *acht, const rgba_pixel *const pixels[], unsigned int cols, unsigned int rows, const unsigned char *importance_map);
LIQ_PRIVATE bool pam_add_to_hash(struct acolorhash_table *acht, unsigned int hash, unsigned int boost, union rgba_as_int px, unsigned int row, unsigned int rows);
LIQ_PRIVATE void pam_freeacolorhist(histogram *h);
LIQ_PRIVATE colormap *pam_colormap(unsigned int colors, void* (*malloc)(size_t), void (*free)(void*));
LIQ_PRIVATE colormap *pam_duplicate_colormap(colormap *map);
LIQ_PRIVATE void pam_freecolormap(colormap *c);
#endif

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@ -1,23 +0,0 @@
# Compiled Object files, Static and Dynamic libs (Shared Objects)
*.o
*.a
*.so
# Folders
_obj
_test
# Architecture specific extensions/prefixes
*.[568vq]
[568vq].out
*.cgo1.go
*.cgo2.c
_cgo_defun.c
_cgo_gotypes.go
_cgo_export.*
_testmain.go
*.exe
*.test

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@ -1,223 +0,0 @@
package lru
import (
"fmt"
"sync"
"github.com/hashicorp/golang-lru/simplelru"
)
const (
// Default2QRecentRatio is the ratio of the 2Q cache dedicated
// to recently added entries that have only been accessed once.
Default2QRecentRatio = 0.25
// Default2QGhostEntries is the default ratio of ghost
// entries kept to track entries recently evicted
Default2QGhostEntries = 0.50
)
// TwoQueueCache is a thread-safe fixed size 2Q cache.
// 2Q is an enhancement over the standard LRU cache
// in that it tracks both frequently and recently used
// entries separately. This avoids a burst in access to new
// entries from evicting frequently used entries. It adds some
// additional tracking overhead to the standard LRU cache, and is
// computationally about 2x the cost, and adds some metadata over
// head. The ARCCache is similar, but does not require setting any
// parameters.
type TwoQueueCache struct {
size int
recentSize int
recent simplelru.LRUCache
frequent simplelru.LRUCache
recentEvict simplelru.LRUCache
lock sync.RWMutex
}
// New2Q creates a new TwoQueueCache using the default
// values for the parameters.
func New2Q(size int) (*TwoQueueCache, error) {
return New2QParams(size, Default2QRecentRatio, Default2QGhostEntries)
}
// New2QParams creates a new TwoQueueCache using the provided
// parameter values.
func New2QParams(size int, recentRatio float64, ghostRatio float64) (*TwoQueueCache, error) {
if size <= 0 {
return nil, fmt.Errorf("invalid size")
}
if recentRatio < 0.0 || recentRatio > 1.0 {
return nil, fmt.Errorf("invalid recent ratio")
}
if ghostRatio < 0.0 || ghostRatio > 1.0 {
return nil, fmt.Errorf("invalid ghost ratio")
}
// Determine the sub-sizes
recentSize := int(float64(size) * recentRatio)
evictSize := int(float64(size) * ghostRatio)
// Allocate the LRUs
recent, err := simplelru.NewLRU(size, nil)
if err != nil {
return nil, err
}
frequent, err := simplelru.NewLRU(size, nil)
if err != nil {
return nil, err
}
recentEvict, err := simplelru.NewLRU(evictSize, nil)
if err != nil {
return nil, err
}
// Initialize the cache
c := &TwoQueueCache{
size: size,
recentSize: recentSize,
recent: recent,
frequent: frequent,
recentEvict: recentEvict,
}
return c, nil
}
// Get looks up a key's value from the cache.
func (c *TwoQueueCache) Get(key interface{}) (value interface{}, ok bool) {
c.lock.Lock()
defer c.lock.Unlock()
// Check if this is a frequent value
if val, ok := c.frequent.Get(key); ok {
return val, ok
}
// If the value is contained in recent, then we
// promote it to frequent
if val, ok := c.recent.Peek(key); ok {
c.recent.Remove(key)
c.frequent.Add(key, val)
return val, ok
}
// No hit
return nil, false
}
// Add adds a value to the cache.
func (c *TwoQueueCache) Add(key, value interface{}) {
c.lock.Lock()
defer c.lock.Unlock()
// Check if the value is frequently used already,
// and just update the value
if c.frequent.Contains(key) {
c.frequent.Add(key, value)
return
}
// Check if the value is recently used, and promote
// the value into the frequent list
if c.recent.Contains(key) {
c.recent.Remove(key)
c.frequent.Add(key, value)
return
}
// If the value was recently evicted, add it to the
// frequently used list
if c.recentEvict.Contains(key) {
c.ensureSpace(true)
c.recentEvict.Remove(key)
c.frequent.Add(key, value)
return
}
// Add to the recently seen list
c.ensureSpace(false)
c.recent.Add(key, value)
return
}
// ensureSpace is used to ensure we have space in the cache
func (c *TwoQueueCache) ensureSpace(recentEvict bool) {
// If we have space, nothing to do
recentLen := c.recent.Len()
freqLen := c.frequent.Len()
if recentLen+freqLen < c.size {
return
}
// If the recent buffer is larger than
// the target, evict from there
if recentLen > 0 && (recentLen > c.recentSize || (recentLen == c.recentSize && !recentEvict)) {
k, _, _ := c.recent.RemoveOldest()
c.recentEvict.Add(k, nil)
return
}
// Remove from the frequent list otherwise
c.frequent.RemoveOldest()
}
// Len returns the number of items in the cache.
func (c *TwoQueueCache) Len() int {
c.lock.RLock()
defer c.lock.RUnlock()
return c.recent.Len() + c.frequent.Len()
}
// Keys returns a slice of the keys in the cache.
// The frequently used keys are first in the returned slice.
func (c *TwoQueueCache) Keys() []interface{} {
c.lock.RLock()
defer c.lock.RUnlock()
k1 := c.frequent.Keys()
k2 := c.recent.Keys()
return append(k1, k2...)
}
// Remove removes the provided key from the cache.
func (c *TwoQueueCache) Remove(key interface{}) {
c.lock.Lock()
defer c.lock.Unlock()
if c.frequent.Remove(key) {
return
}
if c.recent.Remove(key) {
return
}
if c.recentEvict.Remove(key) {
return
}
}
// Purge is used to completely clear the cache.
func (c *TwoQueueCache) Purge() {
c.lock.Lock()
defer c.lock.Unlock()
c.recent.Purge()
c.frequent.Purge()
c.recentEvict.Purge()
}
// Contains is used to check if the cache contains a key
// without updating recency or frequency.
func (c *TwoQueueCache) Contains(key interface{}) bool {
c.lock.RLock()
defer c.lock.RUnlock()
return c.frequent.Contains(key) || c.recent.Contains(key)
}
// Peek is used to inspect the cache value of a key
// without updating recency or frequency.
func (c *TwoQueueCache) Peek(key interface{}) (value interface{}, ok bool) {
c.lock.RLock()
defer c.lock.RUnlock()
if val, ok := c.frequent.Peek(key); ok {
return val, ok
}
return c.recent.Peek(key)
}

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@ -1,362 +0,0 @@
Mozilla Public License, version 2.0
1. Definitions
1.1. "Contributor"
means each individual or legal entity that creates, contributes to the
creation of, or owns Covered Software.
1.2. "Contributor Version"
means the combination of the Contributions of others (if any) used by a
Contributor and that particular Contributor's Contribution.
1.3. "Contribution"
means Covered Software of a particular Contributor.
1.4. "Covered Software"
means Source Code Form to which the initial Contributor has attached the
notice in Exhibit A, the Executable Form of such Source Code Form, and
Modifications of such Source Code Form, in each case including portions
thereof.
1.5. "Incompatible With Secondary Licenses"
means
a. that the initial Contributor has attached the notice described in
Exhibit B to the Covered Software; or
b. that the Covered Software was made available under the terms of
version 1.1 or earlier of the License, but not also under the terms of
a Secondary License.
1.6. "Executable Form"
means any form of the work other than Source Code Form.
1.7. "Larger Work"
means a work that combines Covered Software with other material, in a
separate file or files, that is not Covered Software.
1.8. "License"
means this document.
1.9. "Licensable"
means having the right to grant, to the maximum extent possible, whether
at the time of the initial grant or subsequently, any and all of the
rights conveyed by this License.
1.10. "Modifications"
means any of the following:
a. any file in Source Code Form that results from an addition to,
deletion from, or modification of the contents of Covered Software; or
b. any new file in Source Code Form that contains any Covered Software.
1.11. "Patent Claims" of a Contributor
means any patent claim(s), including without limitation, method,
process, and apparatus claims, in any patent Licensable by such
Contributor that would be infringed, but for the grant of the License,
by the making, using, selling, offering for sale, having made, import,
or transfer of either its Contributions or its Contributor Version.
1.12. "Secondary License"
means either the GNU General Public License, Version 2.0, the GNU Lesser
General Public License, Version 2.1, the GNU Affero General Public
License, Version 3.0, or any later versions of those licenses.
1.13. "Source Code Form"
means the form of the work preferred for making modifications.
1.14. "You" (or "Your")
means an individual or a legal entity exercising rights under this
License. For legal entities, "You" includes any entity that controls, is
controlled by, or is under common control with You. For purposes of this
definition, "control" means (a) the power, direct or indirect, to cause
the direction or management of such entity, whether by contract or
otherwise, or (b) ownership of more than fifty percent (50%) of the
outstanding shares or beneficial ownership of such entity.
2. License Grants and Conditions
2.1. Grants
Each Contributor hereby grants You a world-wide, royalty-free,
non-exclusive license:
a. under intellectual property rights (other than patent or trademark)
Licensable by such Contributor to use, reproduce, make available,
modify, display, perform, distribute, and otherwise exploit its
Contributions, either on an unmodified basis, with Modifications, or
as part of a Larger Work; and
b. under Patent Claims of such Contributor to make, use, sell, offer for
sale, have made, import, and otherwise transfer either its
Contributions or its Contributor Version.
2.2. Effective Date
The licenses granted in Section 2.1 with respect to any Contribution
become effective for each Contribution on the date the Contributor first
distributes such Contribution.
2.3. Limitations on Grant Scope
The licenses granted in this Section 2 are the only rights granted under
this License. No additional rights or licenses will be implied from the
distribution or licensing of Covered Software under this License.
Notwithstanding Section 2.1(b) above, no patent license is granted by a
Contributor:
a. for any code that a Contributor has removed from Covered Software; or
b. for infringements caused by: (i) Your and any other third party's
modifications of Covered Software, or (ii) the combination of its
Contributions with other software (except as part of its Contributor
Version); or
c. under Patent Claims infringed by Covered Software in the absence of
its Contributions.
This License does not grant any rights in the trademarks, service marks,
or logos of any Contributor (except as may be necessary to comply with
the notice requirements in Section 3.4).
2.4. Subsequent Licenses
No Contributor makes additional grants as a result of Your choice to
distribute the Covered Software under a subsequent version of this
License (see Section 10.2) or under the terms of a Secondary License (if
permitted under the terms of Section 3.3).
2.5. Representation
Each Contributor represents that the Contributor believes its
Contributions are its original creation(s) or it has sufficient rights to
grant the rights to its Contributions conveyed by this License.
2.6. Fair Use
This License is not intended to limit any rights You have under
applicable copyright doctrines of fair use, fair dealing, or other
equivalents.
2.7. Conditions
Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in
Section 2.1.
3. Responsibilities
3.1. Distribution of Source Form
All distribution of Covered Software in Source Code Form, including any
Modifications that You create or to which You contribute, must be under
the terms of this License. You must inform recipients that the Source
Code Form of the Covered Software is governed by the terms of this
License, and how they can obtain a copy of this License. You may not
attempt to alter or restrict the recipients' rights in the Source Code
Form.
3.2. Distribution of Executable Form
If You distribute Covered Software in Executable Form then:
a. such Covered Software must also be made available in Source Code Form,
as described in Section 3.1, and You must inform recipients of the
Executable Form how they can obtain a copy of such Source Code Form by
reasonable means in a timely manner, at a charge no more than the cost
of distribution to the recipient; and
b. You may distribute such Executable Form under the terms of this
License, or sublicense it under different terms, provided that the
license for the Executable Form does not attempt to limit or alter the
recipients' rights in the Source Code Form under this License.
3.3. Distribution of a Larger Work
You may create and distribute a Larger Work under terms of Your choice,
provided that You also comply with the requirements of this License for
the Covered Software. If the Larger Work is a combination of Covered
Software with a work governed by one or more Secondary Licenses, and the
Covered Software is not Incompatible With Secondary Licenses, this
License permits You to additionally distribute such Covered Software
under the terms of such Secondary License(s), so that the recipient of
the Larger Work may, at their option, further distribute the Covered
Software under the terms of either this License or such Secondary
License(s).
3.4. Notices
You may not remove or alter the substance of any license notices
(including copyright notices, patent notices, disclaimers of warranty, or
limitations of liability) contained within the Source Code Form of the
Covered Software, except that You may alter any license notices to the
extent required to remedy known factual inaccuracies.
3.5. Application of Additional Terms
You may choose to offer, and to charge a fee for, warranty, support,
indemnity or liability obligations to one or more recipients of Covered
Software. However, You may do so only on Your own behalf, and not on
behalf of any Contributor. You must make it absolutely clear that any
such warranty, support, indemnity, or liability obligation is offered by
You alone, and You hereby agree to indemnify every Contributor for any
liability incurred by such Contributor as a result of warranty, support,
indemnity or liability terms You offer. You may include additional
disclaimers of warranty and limitations of liability specific to any
jurisdiction.
4. Inability to Comply Due to Statute or Regulation
If it is impossible for You to comply with any of the terms of this License
with respect to some or all of the Covered Software due to statute,
judicial order, or regulation then You must: (a) comply with the terms of
this License to the maximum extent possible; and (b) describe the
limitations and the code they affect. Such description must be placed in a
text file included with all distributions of the Covered Software under
this License. Except to the extent prohibited by statute or regulation,
such description must be sufficiently detailed for a recipient of ordinary
skill to be able to understand it.
5. Termination
5.1. The rights granted under this License will terminate automatically if You
fail to comply with any of its terms. However, if You become compliant,
then the rights granted under this License from a particular Contributor
are reinstated (a) provisionally, unless and until such Contributor
explicitly and finally terminates Your grants, and (b) on an ongoing
basis, if such Contributor fails to notify You of the non-compliance by
some reasonable means prior to 60 days after You have come back into
compliance. Moreover, Your grants from a particular Contributor are
reinstated on an ongoing basis if such Contributor notifies You of the
non-compliance by some reasonable means, this is the first time You have
received notice of non-compliance with this License from such
Contributor, and You become compliant prior to 30 days after Your receipt
of the notice.
5.2. If You initiate litigation against any entity by asserting a patent
infringement claim (excluding declaratory judgment actions,
counter-claims, and cross-claims) alleging that a Contributor Version
directly or indirectly infringes any patent, then the rights granted to
You by any and all Contributors for the Covered Software under Section
2.1 of this License shall terminate.
5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user
license agreements (excluding distributors and resellers) which have been
validly granted by You or Your distributors under this License prior to
termination shall survive termination.
6. Disclaimer of Warranty
Covered Software is provided under this License on an "as is" basis,
without warranty of any kind, either expressed, implied, or statutory,
including, without limitation, warranties that the Covered Software is free
of defects, merchantable, fit for a particular purpose or non-infringing.
The entire risk as to the quality and performance of the Covered Software
is with You. Should any Covered Software prove defective in any respect,
You (not any Contributor) assume the cost of any necessary servicing,
repair, or correction. This disclaimer of warranty constitutes an essential
part of this License. No use of any Covered Software is authorized under
this License except under this disclaimer.
7. Limitation of Liability
Under no circumstances and under no legal theory, whether tort (including
negligence), contract, or otherwise, shall any Contributor, or anyone who
distributes Covered Software as permitted above, be liable to You for any
direct, indirect, special, incidental, or consequential damages of any
character including, without limitation, damages for lost profits, loss of
goodwill, work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses, even if such party shall have been
informed of the possibility of such damages. This limitation of liability
shall not apply to liability for death or personal injury resulting from
such party's negligence to the extent applicable law prohibits such
limitation. Some jurisdictions do not allow the exclusion or limitation of
incidental or consequential damages, so this exclusion and limitation may
not apply to You.
8. Litigation
Any litigation relating to this License may be brought only in the courts
of a jurisdiction where the defendant maintains its principal place of
business and such litigation shall be governed by laws of that
jurisdiction, without reference to its conflict-of-law provisions. Nothing
in this Section shall prevent a party's ability to bring cross-claims or
counter-claims.
9. Miscellaneous
This License represents the complete agreement concerning the subject
matter hereof. If any provision of this License is held to be
unenforceable, such provision shall be reformed only to the extent
necessary to make it enforceable. Any law or regulation which provides that
the language of a contract shall be construed against the drafter shall not
be used to construe this License against a Contributor.
10. Versions of the License
10.1. New Versions
Mozilla Foundation is the license steward. Except as provided in Section
10.3, no one other than the license steward has the right to modify or
publish new versions of this License. Each version will be given a
distinguishing version number.
10.2. Effect of New Versions
You may distribute the Covered Software under the terms of the version
of the License under which You originally received the Covered Software,
or under the terms of any subsequent version published by the license
steward.
10.3. Modified Versions
If you create software not governed by this License, and you want to
create a new license for such software, you may create and use a
modified version of this License if you rename the license and remove
any references to the name of the license steward (except to note that
such modified license differs from this License).
10.4. Distributing Source Code Form that is Incompatible With Secondary
Licenses If You choose to distribute Source Code Form that is
Incompatible With Secondary Licenses under the terms of this version of
the License, the notice described in Exhibit B of this License must be
attached.
Exhibit A - Source Code Form License Notice
This Source Code Form is subject to the
terms of the Mozilla Public License, v.
2.0. If a copy of the MPL was not
distributed with this file, You can
obtain one at
http://mozilla.org/MPL/2.0/.
If it is not possible or desirable to put the notice in a particular file,
then You may include the notice in a location (such as a LICENSE file in a
relevant directory) where a recipient would be likely to look for such a
notice.
You may add additional accurate notices of copyright ownership.
Exhibit B - "Incompatible With Secondary Licenses" Notice
This Source Code Form is "Incompatible
With Secondary Licenses", as defined by
the Mozilla Public License, v. 2.0.

View File

@ -1,25 +0,0 @@
golang-lru
==========
This provides the `lru` package which implements a fixed-size
thread safe LRU cache. It is based on the cache in Groupcache.
Documentation
=============
Full docs are available on [Godoc](http://godoc.org/github.com/hashicorp/golang-lru)
Example
=======
Using the LRU is very simple:
```go
l, _ := New(128)
for i := 0; i < 256; i++ {
l.Add(i, nil)
}
if l.Len() != 128 {
panic(fmt.Sprintf("bad len: %v", l.Len()))
}
```

View File

@ -1,257 +0,0 @@
package lru
import (
"sync"
"github.com/hashicorp/golang-lru/simplelru"
)
// ARCCache is a thread-safe fixed size Adaptive Replacement Cache (ARC).
// ARC is an enhancement over the standard LRU cache in that tracks both
// frequency and recency of use. This avoids a burst in access to new
// entries from evicting the frequently used older entries. It adds some
// additional tracking overhead to a standard LRU cache, computationally
// it is roughly 2x the cost, and the extra memory overhead is linear
// with the size of the cache. ARC has been patented by IBM, but is
// similar to the TwoQueueCache (2Q) which requires setting parameters.
type ARCCache struct {
size int // Size is the total capacity of the cache
p int // P is the dynamic preference towards T1 or T2
t1 simplelru.LRUCache // T1 is the LRU for recently accessed items
b1 simplelru.LRUCache // B1 is the LRU for evictions from t1
t2 simplelru.LRUCache // T2 is the LRU for frequently accessed items
b2 simplelru.LRUCache // B2 is the LRU for evictions from t2
lock sync.RWMutex
}
// NewARC creates an ARC of the given size
func NewARC(size int) (*ARCCache, error) {
// Create the sub LRUs
b1, err := simplelru.NewLRU(size, nil)
if err != nil {
return nil, err
}
b2, err := simplelru.NewLRU(size, nil)
if err != nil {
return nil, err
}
t1, err := simplelru.NewLRU(size, nil)
if err != nil {
return nil, err
}
t2, err := simplelru.NewLRU(size, nil)
if err != nil {
return nil, err
}
// Initialize the ARC
c := &ARCCache{
size: size,
p: 0,
t1: t1,
b1: b1,
t2: t2,
b2: b2,
}
return c, nil
}
// Get looks up a key's value from the cache.
func (c *ARCCache) Get(key interface{}) (value interface{}, ok bool) {
c.lock.Lock()
defer c.lock.Unlock()
// If the value is contained in T1 (recent), then
// promote it to T2 (frequent)
if val, ok := c.t1.Peek(key); ok {
c.t1.Remove(key)
c.t2.Add(key, val)
return val, ok
}
// Check if the value is contained in T2 (frequent)
if val, ok := c.t2.Get(key); ok {
return val, ok
}
// No hit
return nil, false
}
// Add adds a value to the cache.
func (c *ARCCache) Add(key, value interface{}) {
c.lock.Lock()
defer c.lock.Unlock()
// Check if the value is contained in T1 (recent), and potentially
// promote it to frequent T2
if c.t1.Contains(key) {
c.t1.Remove(key)
c.t2.Add(key, value)
return
}
// Check if the value is already in T2 (frequent) and update it
if c.t2.Contains(key) {
c.t2.Add(key, value)
return
}
// Check if this value was recently evicted as part of the
// recently used list
if c.b1.Contains(key) {
// T1 set is too small, increase P appropriately
delta := 1
b1Len := c.b1.Len()
b2Len := c.b2.Len()
if b2Len > b1Len {
delta = b2Len / b1Len
}
if c.p+delta >= c.size {
c.p = c.size
} else {
c.p += delta
}
// Potentially need to make room in the cache
if c.t1.Len()+c.t2.Len() >= c.size {
c.replace(false)
}
// Remove from B1
c.b1.Remove(key)
// Add the key to the frequently used list
c.t2.Add(key, value)
return
}
// Check if this value was recently evicted as part of the
// frequently used list
if c.b2.Contains(key) {
// T2 set is too small, decrease P appropriately
delta := 1
b1Len := c.b1.Len()
b2Len := c.b2.Len()
if b1Len > b2Len {
delta = b1Len / b2Len
}
if delta >= c.p {
c.p = 0
} else {
c.p -= delta
}
// Potentially need to make room in the cache
if c.t1.Len()+c.t2.Len() >= c.size {
c.replace(true)
}
// Remove from B2
c.b2.Remove(key)
// Add the key to the frequently used list
c.t2.Add(key, value)
return
}
// Potentially need to make room in the cache
if c.t1.Len()+c.t2.Len() >= c.size {
c.replace(false)
}
// Keep the size of the ghost buffers trim
if c.b1.Len() > c.size-c.p {
c.b1.RemoveOldest()
}
if c.b2.Len() > c.p {
c.b2.RemoveOldest()
}
// Add to the recently seen list
c.t1.Add(key, value)
return
}
// replace is used to adaptively evict from either T1 or T2
// based on the current learned value of P
func (c *ARCCache) replace(b2ContainsKey bool) {
t1Len := c.t1.Len()
if t1Len > 0 && (t1Len > c.p || (t1Len == c.p && b2ContainsKey)) {
k, _, ok := c.t1.RemoveOldest()
if ok {
c.b1.Add(k, nil)
}
} else {
k, _, ok := c.t2.RemoveOldest()
if ok {
c.b2.Add(k, nil)
}
}
}
// Len returns the number of cached entries
func (c *ARCCache) Len() int {
c.lock.RLock()
defer c.lock.RUnlock()
return c.t1.Len() + c.t2.Len()
}
// Keys returns all the cached keys
func (c *ARCCache) Keys() []interface{} {
c.lock.RLock()
defer c.lock.RUnlock()
k1 := c.t1.Keys()
k2 := c.t2.Keys()
return append(k1, k2...)
}
// Remove is used to purge a key from the cache
func (c *ARCCache) Remove(key interface{}) {
c.lock.Lock()
defer c.lock.Unlock()
if c.t1.Remove(key) {
return
}
if c.t2.Remove(key) {
return
}
if c.b1.Remove(key) {
return
}
if c.b2.Remove(key) {
return
}
}
// Purge is used to clear the cache
func (c *ARCCache) Purge() {
c.lock.Lock()
defer c.lock.Unlock()
c.t1.Purge()
c.t2.Purge()
c.b1.Purge()
c.b2.Purge()
}
// Contains is used to check if the cache contains a key
// without updating recency or frequency.
func (c *ARCCache) Contains(key interface{}) bool {
c.lock.RLock()
defer c.lock.RUnlock()
return c.t1.Contains(key) || c.t2.Contains(key)
}
// Peek is used to inspect the cache value of a key
// without updating recency or frequency.
func (c *ARCCache) Peek(key interface{}) (value interface{}, ok bool) {
c.lock.RLock()
defer c.lock.RUnlock()
if val, ok := c.t1.Peek(key); ok {
return val, ok
}
return c.t2.Peek(key)
}

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@ -1,21 +0,0 @@
// Package lru provides three different LRU caches of varying sophistication.
//
// Cache is a simple LRU cache. It is based on the
// LRU implementation in groupcache:
// https://github.com/golang/groupcache/tree/master/lru
//
// TwoQueueCache tracks frequently used and recently used entries separately.
// This avoids a burst of accesses from taking out frequently used entries,
// at the cost of about 2x computational overhead and some extra bookkeeping.
//
// ARCCache is an adaptive replacement cache. It tracks recent evictions as
// well as recent usage in both the frequent and recent caches. Its
// computational overhead is comparable to TwoQueueCache, but the memory
// overhead is linear with the size of the cache.
//
// ARC has been patented by IBM, so do not use it if that is problematic for
// your program.
//
// All caches in this package take locks while operating, and are therefore
// thread-safe for consumers.
package lru

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@ -1 +0,0 @@
module github.com/hashicorp/golang-lru

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@ -1,110 +0,0 @@
package lru
import (
"sync"
"github.com/hashicorp/golang-lru/simplelru"
)
// Cache is a thread-safe fixed size LRU cache.
type Cache struct {
lru simplelru.LRUCache
lock sync.RWMutex
}
// New creates an LRU of the given size.
func New(size int) (*Cache, error) {
return NewWithEvict(size, nil)
}
// NewWithEvict constructs a fixed size cache with the given eviction
// callback.
func NewWithEvict(size int, onEvicted func(key interface{}, value interface{})) (*Cache, error) {
lru, err := simplelru.NewLRU(size, simplelru.EvictCallback(onEvicted))
if err != nil {
return nil, err
}
c := &Cache{
lru: lru,
}
return c, nil
}
// Purge is used to completely clear the cache.
func (c *Cache) Purge() {
c.lock.Lock()
c.lru.Purge()
c.lock.Unlock()
}
// Add adds a value to the cache. Returns true if an eviction occurred.
func (c *Cache) Add(key, value interface{}) (evicted bool) {
c.lock.Lock()
defer c.lock.Unlock()
return c.lru.Add(key, value)
}
// Get looks up a key's value from the cache.
func (c *Cache) Get(key interface{}) (value interface{}, ok bool) {
c.lock.Lock()
defer c.lock.Unlock()
return c.lru.Get(key)
}
// Contains checks if a key is in the cache, without updating the
// recent-ness or deleting it for being stale.
func (c *Cache) Contains(key interface{}) bool {
c.lock.RLock()
defer c.lock.RUnlock()
return c.lru.Contains(key)
}
// Peek returns the key value (or undefined if not found) without updating
// the "recently used"-ness of the key.
func (c *Cache) Peek(key interface{}) (value interface{}, ok bool) {
c.lock.RLock()
defer c.lock.RUnlock()
return c.lru.Peek(key)
}
// ContainsOrAdd checks if a key is in the cache without updating the
// recent-ness or deleting it for being stale, and if not, adds the value.
// Returns whether found and whether an eviction occurred.
func (c *Cache) ContainsOrAdd(key, value interface{}) (ok, evicted bool) {
c.lock.Lock()
defer c.lock.Unlock()
if c.lru.Contains(key) {
return true, false
}
evicted = c.lru.Add(key, value)
return false, evicted
}
// Remove removes the provided key from the cache.
func (c *Cache) Remove(key interface{}) {
c.lock.Lock()
c.lru.Remove(key)
c.lock.Unlock()
}
// RemoveOldest removes the oldest item from the cache.
func (c *Cache) RemoveOldest() {
c.lock.Lock()
c.lru.RemoveOldest()
c.lock.Unlock()
}
// Keys returns a slice of the keys in the cache, from oldest to newest.
func (c *Cache) Keys() []interface{} {
c.lock.RLock()
defer c.lock.RUnlock()
return c.lru.Keys()
}
// Len returns the number of items in the cache.
func (c *Cache) Len() int {
c.lock.RLock()
defer c.lock.RUnlock()
return c.lru.Len()
}

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@ -1,161 +0,0 @@
package simplelru
import (
"container/list"
"errors"
)
// EvictCallback is used to get a callback when a cache entry is evicted
type EvictCallback func(key interface{}, value interface{})
// LRU implements a non-thread safe fixed size LRU cache
type LRU struct {
size int
evictList *list.List
items map[interface{}]*list.Element
onEvict EvictCallback
}
// entry is used to hold a value in the evictList
type entry struct {
key interface{}
value interface{}
}
// NewLRU constructs an LRU of the given size
func NewLRU(size int, onEvict EvictCallback) (*LRU, error) {
if size <= 0 {
return nil, errors.New("Must provide a positive size")
}
c := &LRU{
size: size,
evictList: list.New(),
items: make(map[interface{}]*list.Element),
onEvict: onEvict,
}
return c, nil
}
// Purge is used to completely clear the cache.
func (c *LRU) Purge() {
for k, v := range c.items {
if c.onEvict != nil {
c.onEvict(k, v.Value.(*entry).value)
}
delete(c.items, k)
}
c.evictList.Init()
}
// Add adds a value to the cache. Returns true if an eviction occurred.
func (c *LRU) Add(key, value interface{}) (evicted bool) {
// Check for existing item
if ent, ok := c.items[key]; ok {
c.evictList.MoveToFront(ent)
ent.Value.(*entry).value = value
return false
}
// Add new item
ent := &entry{key, value}
entry := c.evictList.PushFront(ent)
c.items[key] = entry
evict := c.evictList.Len() > c.size
// Verify size not exceeded
if evict {
c.removeOldest()
}
return evict
}
// Get looks up a key's value from the cache.
func (c *LRU) Get(key interface{}) (value interface{}, ok bool) {
if ent, ok := c.items[key]; ok {
c.evictList.MoveToFront(ent)
return ent.Value.(*entry).value, true
}
return
}
// Contains checks if a key is in the cache, without updating the recent-ness
// or deleting it for being stale.
func (c *LRU) Contains(key interface{}) (ok bool) {
_, ok = c.items[key]
return ok
}
// Peek returns the key value (or undefined if not found) without updating
// the "recently used"-ness of the key.
func (c *LRU) Peek(key interface{}) (value interface{}, ok bool) {
var ent *list.Element
if ent, ok = c.items[key]; ok {
return ent.Value.(*entry).value, true
}
return nil, ok
}
// Remove removes the provided key from the cache, returning if the
// key was contained.
func (c *LRU) Remove(key interface{}) (present bool) {
if ent, ok := c.items[key]; ok {
c.removeElement(ent)
return true
}
return false
}
// RemoveOldest removes the oldest item from the cache.
func (c *LRU) RemoveOldest() (key interface{}, value interface{}, ok bool) {
ent := c.evictList.Back()
if ent != nil {
c.removeElement(ent)
kv := ent.Value.(*entry)
return kv.key, kv.value, true
}
return nil, nil, false
}
// GetOldest returns the oldest entry
func (c *LRU) GetOldest() (key interface{}, value interface{}, ok bool) {
ent := c.evictList.Back()
if ent != nil {
kv := ent.Value.(*entry)
return kv.key, kv.value, true
}
return nil, nil, false
}
// Keys returns a slice of the keys in the cache, from oldest to newest.
func (c *LRU) Keys() []interface{} {
keys := make([]interface{}, len(c.items))
i := 0
for ent := c.evictList.Back(); ent != nil; ent = ent.Prev() {
keys[i] = ent.Value.(*entry).key
i++
}
return keys
}
// Len returns the number of items in the cache.
func (c *LRU) Len() int {
return c.evictList.Len()
}
// removeOldest removes the oldest item from the cache.
func (c *LRU) removeOldest() {
ent := c.evictList.Back()
if ent != nil {
c.removeElement(ent)
}
}
// removeElement is used to remove a given list element from the cache
func (c *LRU) removeElement(e *list.Element) {
c.evictList.Remove(e)
kv := e.Value.(*entry)
delete(c.items, kv.key)
if c.onEvict != nil {
c.onEvict(kv.key, kv.value)
}
}

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@ -1,36 +0,0 @@
package simplelru
// LRUCache is the interface for simple LRU cache.
type LRUCache interface {
// Adds a value to the cache, returns true if an eviction occurred and
// updates the "recently used"-ness of the key.
Add(key, value interface{}) bool
// Returns key's value from the cache and
// updates the "recently used"-ness of the key. #value, isFound
Get(key interface{}) (value interface{}, ok bool)
// Check if a key exsists in cache without updating the recent-ness.
Contains(key interface{}) (ok bool)
// Returns key's value without updating the "recently used"-ness of the key.
Peek(key interface{}) (value interface{}, ok bool)
// Removes a key from the cache.
Remove(key interface{}) bool
// Removes the oldest entry from cache.
RemoveOldest() (interface{}, interface{}, bool)
// Returns the oldest entry from the cache. #key, value, isFound
GetOldest() (interface{}, interface{}, bool)
// Returns a slice of the keys in the cache, from oldest to newest.
Keys() []interface{}
// Returns the number of items in the cache.
Len() int
// Clear all cache entries
Purge()
}

3
vendor/golang.org/x/image/AUTHORS generated vendored
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@ -1,3 +0,0 @@
# This source code refers to The Go Authors for copyright purposes.
# The master list of authors is in the main Go distribution,
# visible at http://tip.golang.org/AUTHORS.

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@ -1,3 +0,0 @@
# This source code was written by the Go contributors.
# The master list of contributors is in the main Go distribution,
# visible at http://tip.golang.org/CONTRIBUTORS.

27
vendor/golang.org/x/image/LICENSE generated vendored
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@ -1,27 +0,0 @@
Copyright (c) 2009 The Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

22
vendor/golang.org/x/image/PATENTS generated vendored
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@ -1,22 +0,0 @@
Additional IP Rights Grant (Patents)
"This implementation" means the copyrightable works distributed by
Google as part of the Go project.
Google hereby grants to You a perpetual, worldwide, non-exclusive,
no-charge, royalty-free, irrevocable (except as stated in this section)
patent license to make, have made, use, offer to sell, sell, import,
transfer and otherwise run, modify and propagate the contents of this
implementation of Go, where such license applies only to those patent
claims, both currently owned or controlled by Google and acquired in
the future, licensable by Google that are necessarily infringed by this
implementation of Go. This grant does not include claims that would be
infringed only as a consequence of further modification of this
implementation. If you or your agent or exclusive licensee institute or
order or agree to the institution of patent litigation against any
entity (including a cross-claim or counterclaim in a lawsuit) alleging
that this implementation of Go or any code incorporated within this
implementation of Go constitutes direct or contributory patent
infringement, or inducement of patent infringement, then any patent
rights granted to you under this License for this implementation of Go
shall terminate as of the date such litigation is filed.

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@ -1,199 +0,0 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package bmp implements a BMP image decoder and encoder.
//
// The BMP specification is at http://www.digicamsoft.com/bmp/bmp.html.
package bmp // import "golang.org/x/image/bmp"
import (
"errors"
"image"
"image/color"
"io"
)
// ErrUnsupported means that the input BMP image uses a valid but unsupported
// feature.
var ErrUnsupported = errors.New("bmp: unsupported BMP image")
func readUint16(b []byte) uint16 {
return uint16(b[0]) | uint16(b[1])<<8
}
func readUint32(b []byte) uint32 {
return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
}
// decodePaletted reads an 8 bit-per-pixel BMP image from r.
// If topDown is false, the image rows will be read bottom-up.
func decodePaletted(r io.Reader, c image.Config, topDown bool) (image.Image, error) {
paletted := image.NewPaletted(image.Rect(0, 0, c.Width, c.Height), c.ColorModel.(color.Palette))
if c.Width == 0 || c.Height == 0 {
return paletted, nil
}
var tmp [4]byte
y0, y1, yDelta := c.Height-1, -1, -1
if topDown {
y0, y1, yDelta = 0, c.Height, +1
}
for y := y0; y != y1; y += yDelta {
p := paletted.Pix[y*paletted.Stride : y*paletted.Stride+c.Width]
if _, err := io.ReadFull(r, p); err != nil {
return nil, err
}
// Each row is 4-byte aligned.
if c.Width%4 != 0 {
_, err := io.ReadFull(r, tmp[:4-c.Width%4])
if err != nil {
return nil, err
}
}
}
return paletted, nil
}
// decodeRGB reads a 24 bit-per-pixel BMP image from r.
// If topDown is false, the image rows will be read bottom-up.
func decodeRGB(r io.Reader, c image.Config, topDown bool) (image.Image, error) {
rgba := image.NewRGBA(image.Rect(0, 0, c.Width, c.Height))
if c.Width == 0 || c.Height == 0 {
return rgba, nil
}
// There are 3 bytes per pixel, and each row is 4-byte aligned.
b := make([]byte, (3*c.Width+3)&^3)
y0, y1, yDelta := c.Height-1, -1, -1
if topDown {
y0, y1, yDelta = 0, c.Height, +1
}
for y := y0; y != y1; y += yDelta {
if _, err := io.ReadFull(r, b); err != nil {
return nil, err
}
p := rgba.Pix[y*rgba.Stride : y*rgba.Stride+c.Width*4]
for i, j := 0, 0; i < len(p); i, j = i+4, j+3 {
// BMP images are stored in BGR order rather than RGB order.
p[i+0] = b[j+2]
p[i+1] = b[j+1]
p[i+2] = b[j+0]
p[i+3] = 0xFF
}
}
return rgba, nil
}
// decodeNRGBA reads a 32 bit-per-pixel BMP image from r.
// If topDown is false, the image rows will be read bottom-up.
func decodeNRGBA(r io.Reader, c image.Config, topDown bool) (image.Image, error) {
rgba := image.NewNRGBA(image.Rect(0, 0, c.Width, c.Height))
if c.Width == 0 || c.Height == 0 {
return rgba, nil
}
y0, y1, yDelta := c.Height-1, -1, -1
if topDown {
y0, y1, yDelta = 0, c.Height, +1
}
for y := y0; y != y1; y += yDelta {
p := rgba.Pix[y*rgba.Stride : y*rgba.Stride+c.Width*4]
if _, err := io.ReadFull(r, p); err != nil {
return nil, err
}
for i := 0; i < len(p); i += 4 {
// BMP images are stored in BGRA order rather than RGBA order.
p[i+0], p[i+2] = p[i+2], p[i+0]
}
}
return rgba, nil
}
// Decode reads a BMP image from r and returns it as an image.Image.
// Limitation: The file must be 8, 24 or 32 bits per pixel.
func Decode(r io.Reader) (image.Image, error) {
c, bpp, topDown, err := decodeConfig(r)
if err != nil {
return nil, err
}
switch bpp {
case 8:
return decodePaletted(r, c, topDown)
case 24:
return decodeRGB(r, c, topDown)
case 32:
return decodeNRGBA(r, c, topDown)
}
panic("unreachable")
}
// DecodeConfig returns the color model and dimensions of a BMP image without
// decoding the entire image.
// Limitation: The file must be 8, 24 or 32 bits per pixel.
func DecodeConfig(r io.Reader) (image.Config, error) {
config, _, _, err := decodeConfig(r)
return config, err
}
func decodeConfig(r io.Reader) (config image.Config, bitsPerPixel int, topDown bool, err error) {
// We only support those BMP images that are a BITMAPFILEHEADER
// immediately followed by a BITMAPINFOHEADER.
const (
fileHeaderLen = 14
infoHeaderLen = 40
)
var b [1024]byte
if _, err := io.ReadFull(r, b[:fileHeaderLen+infoHeaderLen]); err != nil {
return image.Config{}, 0, false, err
}
if string(b[:2]) != "BM" {
return image.Config{}, 0, false, errors.New("bmp: invalid format")
}
offset := readUint32(b[10:14])
if readUint32(b[14:18]) != infoHeaderLen {
return image.Config{}, 0, false, ErrUnsupported
}
width := int(int32(readUint32(b[18:22])))
height := int(int32(readUint32(b[22:26])))
if height < 0 {
height, topDown = -height, true
}
if width < 0 || height < 0 {
return image.Config{}, 0, false, ErrUnsupported
}
// We only support 1 plane, 8 or 24 bits per pixel and no compression.
planes, bpp, compression := readUint16(b[26:28]), readUint16(b[28:30]), readUint32(b[30:34])
if planes != 1 || compression != 0 {
return image.Config{}, 0, false, ErrUnsupported
}
switch bpp {
case 8:
if offset != fileHeaderLen+infoHeaderLen+256*4 {
return image.Config{}, 0, false, ErrUnsupported
}
_, err = io.ReadFull(r, b[:256*4])
if err != nil {
return image.Config{}, 0, false, err
}
pcm := make(color.Palette, 256)
for i := range pcm {
// BMP images are stored in BGR order rather than RGB order.
// Every 4th byte is padding.
pcm[i] = color.RGBA{b[4*i+2], b[4*i+1], b[4*i+0], 0xFF}
}
return image.Config{ColorModel: pcm, Width: width, Height: height}, 8, topDown, nil
case 24:
if offset != fileHeaderLen+infoHeaderLen {
return image.Config{}, 0, false, ErrUnsupported
}
return image.Config{ColorModel: color.RGBAModel, Width: width, Height: height}, 24, topDown, nil
case 32:
if offset != fileHeaderLen+infoHeaderLen {
return image.Config{}, 0, false, ErrUnsupported
}
return image.Config{ColorModel: color.RGBAModel, Width: width, Height: height}, 32, topDown, nil
}
return image.Config{}, 0, false, ErrUnsupported
}
func init() {
image.RegisterFormat("bmp", "BM????\x00\x00\x00\x00", Decode, DecodeConfig)
}

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@ -1,166 +0,0 @@
// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package bmp
import (
"encoding/binary"
"errors"
"image"
"io"
)
type header struct {
sigBM [2]byte
fileSize uint32
resverved [2]uint16
pixOffset uint32
dibHeaderSize uint32
width uint32
height uint32
colorPlane uint16
bpp uint16
compression uint32
imageSize uint32
xPixelsPerMeter uint32
yPixelsPerMeter uint32
colorUse uint32
colorImportant uint32
}
func encodePaletted(w io.Writer, pix []uint8, dx, dy, stride, step int) error {
var padding []byte
if dx < step {
padding = make([]byte, step-dx)
}
for y := dy - 1; y >= 0; y-- {
min := y*stride + 0
max := y*stride + dx
if _, err := w.Write(pix[min:max]); err != nil {
return err
}
if padding != nil {
if _, err := w.Write(padding); err != nil {
return err
}
}
}
return nil
}
func encodeRGBA(w io.Writer, pix []uint8, dx, dy, stride, step int) error {
buf := make([]byte, step)
for y := dy - 1; y >= 0; y-- {
min := y*stride + 0
max := y*stride + dx*4
off := 0
for i := min; i < max; i += 4 {
buf[off+2] = pix[i+0]
buf[off+1] = pix[i+1]
buf[off+0] = pix[i+2]
off += 3
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
func encode(w io.Writer, m image.Image, step int) error {
b := m.Bounds()
buf := make([]byte, step)
for y := b.Max.Y - 1; y >= b.Min.Y; y-- {
off := 0
for x := b.Min.X; x < b.Max.X; x++ {
r, g, b, _ := m.At(x, y).RGBA()
buf[off+2] = byte(r >> 8)
buf[off+1] = byte(g >> 8)
buf[off+0] = byte(b >> 8)
off += 3
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
// Encode writes the image m to w in BMP format.
func Encode(w io.Writer, m image.Image) error {
d := m.Bounds().Size()
if d.X < 0 || d.Y < 0 {
return errors.New("bmp: negative bounds")
}
h := &header{
sigBM: [2]byte{'B', 'M'},
fileSize: 14 + 40,
pixOffset: 14 + 40,
dibHeaderSize: 40,
width: uint32(d.X),
height: uint32(d.Y),
colorPlane: 1,
}
var step int
var palette []byte
switch m := m.(type) {
case *image.Gray:
step = (d.X + 3) &^ 3
palette = make([]byte, 1024)
for i := 0; i < 256; i++ {
palette[i*4+0] = uint8(i)
palette[i*4+1] = uint8(i)
palette[i*4+2] = uint8(i)
palette[i*4+3] = 0xFF
}
h.imageSize = uint32(d.Y * step)
h.fileSize += uint32(len(palette)) + h.imageSize
h.pixOffset += uint32(len(palette))
h.bpp = 8
case *image.Paletted:
step = (d.X + 3) &^ 3
palette = make([]byte, 1024)
for i := 0; i < len(m.Palette) && i < 256; i++ {
r, g, b, _ := m.Palette[i].RGBA()
palette[i*4+0] = uint8(b >> 8)
palette[i*4+1] = uint8(g >> 8)
palette[i*4+2] = uint8(r >> 8)
palette[i*4+3] = 0xFF
}
h.imageSize = uint32(d.Y * step)
h.fileSize += uint32(len(palette)) + h.imageSize
h.pixOffset += uint32(len(palette))
h.bpp = 8
default:
step = (3*d.X + 3) &^ 3
h.imageSize = uint32(d.Y * step)
h.fileSize += h.imageSize
h.bpp = 24
}
if err := binary.Write(w, binary.LittleEndian, h); err != nil {
return err
}
if palette != nil {
if err := binary.Write(w, binary.LittleEndian, palette); err != nil {
return err
}
}
if d.X == 0 || d.Y == 0 {
return nil
}
switch m := m.(type) {
case *image.Gray:
return encodePaletted(w, m.Pix, d.X, d.Y, m.Stride, step)
case *image.Paletted:
return encodePaletted(w, m.Pix, d.X, d.Y, m.Stride, step)
case *image.RGBA:
return encodeRGBA(w, m.Pix, d.X, d.Y, m.Stride, step)
}
return encode(w, m, step)
}

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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package draw provides image composition functions.
//
// See "The Go image/draw package" for an introduction to this package:
// http://golang.org/doc/articles/image_draw.html
//
// This package is a superset of and a drop-in replacement for the image/draw
// package in the standard library.
package draw
// This file, and the go1_*.go files, just contains the API exported by the
// image/draw package in the standard library. Other files in this package
// provide additional features.
import (
"image"
"image/draw"
)
// Draw calls DrawMask with a nil mask.
func Draw(dst Image, r image.Rectangle, src image.Image, sp image.Point, op Op) {
draw.Draw(dst, r, src, sp, draw.Op(op))
}
// DrawMask aligns r.Min in dst with sp in src and mp in mask and then
// replaces the rectangle r in dst with the result of a Porter-Duff
// composition. A nil mask is treated as opaque.
func DrawMask(dst Image, r image.Rectangle, src image.Image, sp image.Point, mask image.Image, mp image.Point, op Op) {
draw.DrawMask(dst, r, src, sp, mask, mp, draw.Op(op))
}
// FloydSteinberg is a Drawer that is the Src Op with Floyd-Steinberg error
// diffusion.
var FloydSteinberg Drawer = floydSteinberg{}
type floydSteinberg struct{}
func (floydSteinberg) Draw(dst Image, r image.Rectangle, src image.Image, sp image.Point) {
draw.FloydSteinberg.Draw(dst, r, src, sp)
}

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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build !go1.9,!go1.8.typealias
package draw
import (
"image"
"image/color"
"image/draw"
)
// Drawer contains the Draw method.
type Drawer interface {
// Draw aligns r.Min in dst with sp in src and then replaces the
// rectangle r in dst with the result of drawing src on dst.
Draw(dst Image, r image.Rectangle, src image.Image, sp image.Point)
}
// Image is an image.Image with a Set method to change a single pixel.
type Image interface {
image.Image
Set(x, y int, c color.Color)
}
// Op is a Porter-Duff compositing operator.
type Op int
const (
// Over specifies ``(src in mask) over dst''.
Over Op = Op(draw.Over)
// Src specifies ``src in mask''.
Src Op = Op(draw.Src)
)
// Draw implements the Drawer interface by calling the Draw function with
// this Op.
func (op Op) Draw(dst Image, r image.Rectangle, src image.Image, sp image.Point) {
(draw.Op(op)).Draw(dst, r, src, sp)
}
// Quantizer produces a palette for an image.
type Quantizer interface {
// Quantize appends up to cap(p) - len(p) colors to p and returns the
// updated palette suitable for converting m to a paletted image.
Quantize(p color.Palette, m image.Image) color.Palette
}

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// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build go1.9 go1.8.typealias
package draw
import (
"image/draw"
)
// We use type aliases (new in Go 1.9) for the exported names from the standard
// library's image/draw package. This is not merely syntactic sugar for
//
// type Drawer draw.Drawer
//
// as aliasing means that the types in this package, such as draw.Image and
// draw.Op, are identical to the corresponding draw.Image and draw.Op types in
// the standard library. In comparison, prior to Go 1.9, the code in go1_8.go
// defines new types that mimic the old but are different types.
//
// The package documentation, in draw.go, explicitly gives the intent of this
// package:
//
// This package is a superset of and a drop-in replacement for the
// image/draw package in the standard library.
//
// Drop-in replacement means that I can replace all of my "image/draw" imports
// with "golang.org/x/image/draw", to access additional features in this
// package, and no further changes are required. That's mostly true, but not
// completely true unless we use type aliases.
//
// Without type aliases, users might need to import both "image/draw" and
// "golang.org/x/image/draw" in order to convert from two conceptually
// equivalent but different (from the compiler's point of view) types, such as
// from one draw.Op type to another draw.Op type, to satisfy some other
// interface or function signature.
// Drawer contains the Draw method.
type Drawer = draw.Drawer
// Image is an image.Image with a Set method to change a single pixel.
type Image = draw.Image
// Op is a Porter-Duff compositing operator.
type Op = draw.Op
const (
// Over specifies ``(src in mask) over dst''.
Over Op = draw.Over
// Src specifies ``src in mask''.
Src Op = draw.Src
)
// Quantizer produces a palette for an image.
type Quantizer = draw.Quantizer

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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:generate go run gen.go
package draw
import (
"image"
"image/color"
"math"
"sync"
"golang.org/x/image/math/f64"
)
// Copy copies the part of the source image defined by src and sr and writes
// the result of a Porter-Duff composition to the part of the destination image
// defined by dst and the translation of sr so that sr.Min translates to dp.
func Copy(dst Image, dp image.Point, src image.Image, sr image.Rectangle, op Op, opts *Options) {
var o Options
if opts != nil {
o = *opts
}
dr := sr.Add(dp.Sub(sr.Min))
if o.DstMask == nil {
DrawMask(dst, dr, src, sr.Min, o.SrcMask, o.SrcMaskP.Add(sr.Min), op)
} else {
NearestNeighbor.Scale(dst, dr, src, sr, op, opts)
}
}
// Scaler scales the part of the source image defined by src and sr and writes
// the result of a Porter-Duff composition to the part of the destination image
// defined by dst and dr.
//
// A Scaler is safe to use concurrently.
type Scaler interface {
Scale(dst Image, dr image.Rectangle, src image.Image, sr image.Rectangle, op Op, opts *Options)
}
// Transformer transforms the part of the source image defined by src and sr
// and writes the result of a Porter-Duff composition to the part of the
// destination image defined by dst and the affine transform m applied to sr.
//
// For example, if m is the matrix
//
// m00 m01 m02
// m10 m11 m12
//
// then the src-space point (sx, sy) maps to the dst-space point
// (m00*sx + m01*sy + m02, m10*sx + m11*sy + m12).
//
// A Transformer is safe to use concurrently.
type Transformer interface {
Transform(dst Image, m f64.Aff3, src image.Image, sr image.Rectangle, op Op, opts *Options)
}
// Options are optional parameters to Copy, Scale and Transform.
//
// A nil *Options means to use the default (zero) values of each field.
type Options struct {
// Masks limit what parts of the dst image are drawn to and what parts of
// the src image are drawn from.
//
// A dst or src mask image having a zero alpha (transparent) pixel value in
// the respective coordinate space means that that dst pixel is entirely
// unaffected or that src pixel is considered transparent black. A full
// alpha (opaque) value means that the dst pixel is maximally affected or
// the src pixel contributes maximally. The default values, nil, are
// equivalent to fully opaque, infinitely large mask images.
//
// The DstMask is otherwise known as a clip mask, and its pixels map 1:1 to
// the dst image's pixels. DstMaskP in DstMask space corresponds to
// image.Point{X:0, Y:0} in dst space. For example, when limiting
// repainting to a 'dirty rectangle', use that image.Rectangle and a zero
// image.Point as the DstMask and DstMaskP.
//
// The SrcMask's pixels map 1:1 to the src image's pixels. SrcMaskP in
// SrcMask space corresponds to image.Point{X:0, Y:0} in src space. For
// example, when drawing font glyphs in a uniform color, use an
// *image.Uniform as the src, and use the glyph atlas image and the
// per-glyph offset as SrcMask and SrcMaskP:
// Copy(dst, dp, image.NewUniform(color), image.Rect(0, 0, glyphWidth, glyphHeight), &Options{
// SrcMask: glyphAtlas,
// SrcMaskP: glyphOffset,
// })
DstMask image.Image
DstMaskP image.Point
SrcMask image.Image
SrcMaskP image.Point
// TODO: a smooth vs sharp edges option, for arbitrary rotations?
}
// Interpolator is an interpolation algorithm, when dst and src pixels don't
// have a 1:1 correspondence.
//
// Of the interpolators provided by this package:
// - NearestNeighbor is fast but usually looks worst.
// - CatmullRom is slow but usually looks best.
// - ApproxBiLinear has reasonable speed and quality.
//
// The time taken depends on the size of dr. For kernel interpolators, the
// speed also depends on the size of sr, and so are often slower than
// non-kernel interpolators, especially when scaling down.
type Interpolator interface {
Scaler
Transformer
}
// Kernel is an interpolator that blends source pixels weighted by a symmetric
// kernel function.
type Kernel struct {
// Support is the kernel support and must be >= 0. At(t) is assumed to be
// zero when t >= Support.
Support float64
// At is the kernel function. It will only be called with t in the
// range [0, Support).
At func(t float64) float64
}
// Scale implements the Scaler interface.
func (q *Kernel) Scale(dst Image, dr image.Rectangle, src image.Image, sr image.Rectangle, op Op, opts *Options) {
q.newScaler(dr.Dx(), dr.Dy(), sr.Dx(), sr.Dy(), false).Scale(dst, dr, src, sr, op, opts)
}
// NewScaler returns a Scaler that is optimized for scaling multiple times with
// the same fixed destination and source width and height.
func (q *Kernel) NewScaler(dw, dh, sw, sh int) Scaler {
return q.newScaler(dw, dh, sw, sh, true)
}
func (q *Kernel) newScaler(dw, dh, sw, sh int, usePool bool) Scaler {
z := &kernelScaler{
kernel: q,
dw: int32(dw),
dh: int32(dh),
sw: int32(sw),
sh: int32(sh),
horizontal: newDistrib(q, int32(dw), int32(sw)),
vertical: newDistrib(q, int32(dh), int32(sh)),
}
if usePool {
z.pool.New = func() interface{} {
tmp := z.makeTmpBuf()
return &tmp
}
}
return z
}
var (
// NearestNeighbor is the nearest neighbor interpolator. It is very fast,
// but usually gives very low quality results. When scaling up, the result
// will look 'blocky'.
NearestNeighbor = Interpolator(nnInterpolator{})
// ApproxBiLinear is a mixture of the nearest neighbor and bi-linear
// interpolators. It is fast, but usually gives medium quality results.
//
// It implements bi-linear interpolation when upscaling and a bi-linear
// blend of the 4 nearest neighbor pixels when downscaling. This yields
// nicer quality than nearest neighbor interpolation when upscaling, but
// the time taken is independent of the number of source pixels, unlike the
// bi-linear interpolator. When downscaling a large image, the performance
// difference can be significant.
ApproxBiLinear = Interpolator(ablInterpolator{})
// BiLinear is the tent kernel. It is slow, but usually gives high quality
// results.
BiLinear = &Kernel{1, func(t float64) float64 {
return 1 - t
}}
// CatmullRom is the Catmull-Rom kernel. It is very slow, but usually gives
// very high quality results.
//
// It is an instance of the more general cubic BC-spline kernel with parameters
// B=0 and C=0.5. See Mitchell and Netravali, "Reconstruction Filters in
// Computer Graphics", Computer Graphics, Vol. 22, No. 4, pp. 221-228.
CatmullRom = &Kernel{2, func(t float64) float64 {
if t < 1 {
return (1.5*t-2.5)*t*t + 1
}
return ((-0.5*t+2.5)*t-4)*t + 2
}}
// TODO: a Kaiser-Bessel kernel?
)
type nnInterpolator struct{}
type ablInterpolator struct{}
type kernelScaler struct {
kernel *Kernel
dw, dh, sw, sh int32
horizontal, vertical distrib
pool sync.Pool
}
func (z *kernelScaler) makeTmpBuf() [][4]float64 {
return make([][4]float64, z.dw*z.sh)
}
// source is a range of contribs, their inverse total weight, and that ITW
// divided by 0xffff.
type source struct {
i, j int32
invTotalWeight float64
invTotalWeightFFFF float64
}
// contrib is the weight of a column or row.
type contrib struct {
coord int32
weight float64
}
// distrib measures how source pixels are distributed over destination pixels.
type distrib struct {
// sources are what contribs each column or row in the source image owns,
// and the total weight of those contribs.
sources []source
// contribs are the contributions indexed by sources[s].i and sources[s].j.
contribs []contrib
}
// newDistrib returns a distrib that distributes sw source columns (or rows)
// over dw destination columns (or rows).
func newDistrib(q *Kernel, dw, sw int32) distrib {
scale := float64(sw) / float64(dw)
halfWidth, kernelArgScale := q.Support, 1.0
// When shrinking, broaden the effective kernel support so that we still
// visit every source pixel.
if scale > 1 {
halfWidth *= scale
kernelArgScale = 1 / scale
}
// Make the sources slice, one source for each column or row, and temporarily
// appropriate its elements' fields so that invTotalWeight is the scaled
// coordinate of the source column or row, and i and j are the lower and
// upper bounds of the range of destination columns or rows affected by the
// source column or row.
n, sources := int32(0), make([]source, dw)
for x := range sources {
center := (float64(x)+0.5)*scale - 0.5
i := int32(math.Floor(center - halfWidth))
if i < 0 {
i = 0
}
j := int32(math.Ceil(center + halfWidth))
if j > sw {
j = sw
if j < i {
j = i
}
}
sources[x] = source{i: i, j: j, invTotalWeight: center}
n += j - i
}
contribs := make([]contrib, 0, n)
for k, b := range sources {
totalWeight := 0.0
l := int32(len(contribs))
for coord := b.i; coord < b.j; coord++ {
t := abs((b.invTotalWeight - float64(coord)) * kernelArgScale)
if t >= q.Support {
continue
}
weight := q.At(t)
if weight == 0 {
continue
}
totalWeight += weight
contribs = append(contribs, contrib{coord, weight})
}
totalWeight = 1 / totalWeight
sources[k] = source{
i: l,
j: int32(len(contribs)),
invTotalWeight: totalWeight,
invTotalWeightFFFF: totalWeight / 0xffff,
}
}
return distrib{sources, contribs}
}
// abs is like math.Abs, but it doesn't care about negative zero, infinities or
// NaNs.
func abs(f float64) float64 {
if f < 0 {
f = -f
}
return f
}
// ftou converts the range [0.0, 1.0] to [0, 0xffff].
func ftou(f float64) uint16 {
i := int32(0xffff*f + 0.5)
if i > 0xffff {
return 0xffff
}
if i > 0 {
return uint16(i)
}
return 0
}
// fffftou converts the range [0.0, 65535.0] to [0, 0xffff].
func fffftou(f float64) uint16 {
i := int32(f + 0.5)
if i > 0xffff {
return 0xffff
}
if i > 0 {
return uint16(i)
}
return 0
}
// invert returns the inverse of m.
//
// TODO: move this into the f64 package, once we work out the convention for
// matrix methods in that package: do they modify the receiver, take a dst
// pointer argument, or return a new value?
func invert(m *f64.Aff3) f64.Aff3 {
m00 := +m[3*1+1]
m01 := -m[3*0+1]
m02 := +m[3*1+2]*m[3*0+1] - m[3*1+1]*m[3*0+2]
m10 := -m[3*1+0]
m11 := +m[3*0+0]
m12 := +m[3*1+0]*m[3*0+2] - m[3*1+2]*m[3*0+0]
det := m00*m11 - m10*m01
return f64.Aff3{
m00 / det,
m01 / det,
m02 / det,
m10 / det,
m11 / det,
m12 / det,
}
}
func matMul(p, q *f64.Aff3) f64.Aff3 {
return f64.Aff3{
p[3*0+0]*q[3*0+0] + p[3*0+1]*q[3*1+0],
p[3*0+0]*q[3*0+1] + p[3*0+1]*q[3*1+1],
p[3*0+0]*q[3*0+2] + p[3*0+1]*q[3*1+2] + p[3*0+2],
p[3*1+0]*q[3*0+0] + p[3*1+1]*q[3*1+0],
p[3*1+0]*q[3*0+1] + p[3*1+1]*q[3*1+1],
p[3*1+0]*q[3*0+2] + p[3*1+1]*q[3*1+2] + p[3*1+2],
}
}
// transformRect returns a rectangle dr that contains sr transformed by s2d.
func transformRect(s2d *f64.Aff3, sr *image.Rectangle) (dr image.Rectangle) {
ps := [...]image.Point{
{sr.Min.X, sr.Min.Y},
{sr.Max.X, sr.Min.Y},
{sr.Min.X, sr.Max.Y},
{sr.Max.X, sr.Max.Y},
}
for i, p := range ps {
sxf := float64(p.X)
syf := float64(p.Y)
dx := int(math.Floor(s2d[0]*sxf + s2d[1]*syf + s2d[2]))
dy := int(math.Floor(s2d[3]*sxf + s2d[4]*syf + s2d[5]))
// The +1 adjustments below are because an image.Rectangle is inclusive
// on the low end but exclusive on the high end.
if i == 0 {
dr = image.Rectangle{
Min: image.Point{dx + 0, dy + 0},
Max: image.Point{dx + 1, dy + 1},
}
continue
}
if dr.Min.X > dx {
dr.Min.X = dx
}
dx++
if dr.Max.X < dx {
dr.Max.X = dx
}
if dr.Min.Y > dy {
dr.Min.Y = dy
}
dy++
if dr.Max.Y < dy {
dr.Max.Y = dy
}
}
return dr
}
func clipAffectedDestRect(adr image.Rectangle, dstMask image.Image, dstMaskP image.Point) (image.Rectangle, image.Image) {
if dstMask == nil {
return adr, nil
}
// TODO: enable this fast path once Go 1.5 is released, where an
// image.Rectangle implements image.Image.
// if r, ok := dstMask.(image.Rectangle); ok {
// return adr.Intersect(r.Sub(dstMaskP)), nil
// }
// TODO: clip to dstMask.Bounds() if the color model implies that out-of-bounds means 0 alpha?
return adr, dstMask
}
func transform_Uniform(dst Image, dr, adr image.Rectangle, d2s *f64.Aff3, src *image.Uniform, sr image.Rectangle, bias image.Point, op Op) {
switch op {
case Over:
switch dst := dst.(type) {
case *image.RGBA:
pr, pg, pb, pa := src.C.RGBA()
pa1 := (0xffff - pa) * 0x101
for dy := int32(adr.Min.Y); dy < int32(adr.Max.Y); dy++ {
dyf := float64(dr.Min.Y+int(dy)) + 0.5
d := dst.PixOffset(dr.Min.X+adr.Min.X, dr.Min.Y+int(dy))
for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx, d = dx+1, d+4 {
dxf := float64(dr.Min.X+int(dx)) + 0.5
sx0 := int(d2s[0]*dxf+d2s[1]*dyf+d2s[2]) + bias.X
sy0 := int(d2s[3]*dxf+d2s[4]*dyf+d2s[5]) + bias.Y
if !(image.Point{sx0, sy0}).In(sr) {
continue
}
dst.Pix[d+0] = uint8((uint32(dst.Pix[d+0])*pa1/0xffff + pr) >> 8)
dst.Pix[d+1] = uint8((uint32(dst.Pix[d+1])*pa1/0xffff + pg) >> 8)
dst.Pix[d+2] = uint8((uint32(dst.Pix[d+2])*pa1/0xffff + pb) >> 8)
dst.Pix[d+3] = uint8((uint32(dst.Pix[d+3])*pa1/0xffff + pa) >> 8)
}
}
default:
pr, pg, pb, pa := src.C.RGBA()
pa1 := 0xffff - pa
dstColorRGBA64 := &color.RGBA64{}
dstColor := color.Color(dstColorRGBA64)
for dy := int32(adr.Min.Y); dy < int32(adr.Max.Y); dy++ {
dyf := float64(dr.Min.Y+int(dy)) + 0.5
for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx++ {
dxf := float64(dr.Min.X+int(dx)) + 0.5
sx0 := int(d2s[0]*dxf+d2s[1]*dyf+d2s[2]) + bias.X
sy0 := int(d2s[3]*dxf+d2s[4]*dyf+d2s[5]) + bias.Y
if !(image.Point{sx0, sy0}).In(sr) {
continue
}
qr, qg, qb, qa := dst.At(dr.Min.X+int(dx), dr.Min.Y+int(dy)).RGBA()
dstColorRGBA64.R = uint16(qr*pa1/0xffff + pr)
dstColorRGBA64.G = uint16(qg*pa1/0xffff + pg)
dstColorRGBA64.B = uint16(qb*pa1/0xffff + pb)
dstColorRGBA64.A = uint16(qa*pa1/0xffff + pa)
dst.Set(dr.Min.X+int(dx), dr.Min.Y+int(dy), dstColor)
}
}
}
case Src:
switch dst := dst.(type) {
case *image.RGBA:
pr, pg, pb, pa := src.C.RGBA()
pr8 := uint8(pr >> 8)
pg8 := uint8(pg >> 8)
pb8 := uint8(pb >> 8)
pa8 := uint8(pa >> 8)
for dy := int32(adr.Min.Y); dy < int32(adr.Max.Y); dy++ {
dyf := float64(dr.Min.Y+int(dy)) + 0.5
d := dst.PixOffset(dr.Min.X+adr.Min.X, dr.Min.Y+int(dy))
for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx, d = dx+1, d+4 {
dxf := float64(dr.Min.X+int(dx)) + 0.5
sx0 := int(d2s[0]*dxf+d2s[1]*dyf+d2s[2]) + bias.X
sy0 := int(d2s[3]*dxf+d2s[4]*dyf+d2s[5]) + bias.Y
if !(image.Point{sx0, sy0}).In(sr) {
continue
}
dst.Pix[d+0] = pr8
dst.Pix[d+1] = pg8
dst.Pix[d+2] = pb8
dst.Pix[d+3] = pa8
}
}
default:
pr, pg, pb, pa := src.C.RGBA()
dstColorRGBA64 := &color.RGBA64{
uint16(pr),
uint16(pg),
uint16(pb),
uint16(pa),
}
dstColor := color.Color(dstColorRGBA64)
for dy := int32(adr.Min.Y); dy < int32(adr.Max.Y); dy++ {
dyf := float64(dr.Min.Y+int(dy)) + 0.5
for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx++ {
dxf := float64(dr.Min.X+int(dx)) + 0.5
sx0 := int(d2s[0]*dxf+d2s[1]*dyf+d2s[2]) + bias.X
sy0 := int(d2s[3]*dxf+d2s[4]*dyf+d2s[5]) + bias.Y
if !(image.Point{sx0, sy0}).In(sr) {
continue
}
dst.Set(dr.Min.X+int(dx), dr.Min.Y+int(dy), dstColor)
}
}
}
}
}
func opaque(m image.Image) bool {
o, ok := m.(interface {
Opaque() bool
})
return ok && o.Opaque()
}

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@ -1,37 +0,0 @@
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package f64 implements float64 vector and matrix types.
package f64 // import "golang.org/x/image/math/f64"
// Vec2 is a 2-element vector.
type Vec2 [2]float64
// Vec3 is a 3-element vector.
type Vec3 [3]float64
// Vec4 is a 4-element vector.
type Vec4 [4]float64
// Mat3 is a 3x3 matrix in row major order.
//
// m[3*r + c] is the element in the r'th row and c'th column.
type Mat3 [9]float64
// Mat4 is a 4x4 matrix in row major order.
//
// m[4*r + c] is the element in the r'th row and c'th column.
type Mat4 [16]float64
// Aff3 is a 3x3 affine transformation matrix in row major order, where the
// bottom row is implicitly [0 0 1].
//
// m[3*r + c] is the element in the r'th row and c'th column.
type Aff3 [6]float64
// Aff4 is a 4x4 affine transformation matrix in row major order, where the
// bottom row is implicitly [0 0 0 1].
//
// m[4*r + c] is the element in the r'th row and c'th column.
type Aff4 [12]float64

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@ -1,193 +0,0 @@
// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package riff implements the Resource Interchange File Format, used by media
// formats such as AVI, WAVE and WEBP.
//
// A RIFF stream contains a sequence of chunks. Each chunk consists of an 8-byte
// header (containing a 4-byte chunk type and a 4-byte chunk length), the chunk
// data (presented as an io.Reader), and some padding bytes.
//
// A detailed description of the format is at
// http://www.tactilemedia.com/info/MCI_Control_Info.html
package riff // import "golang.org/x/image/riff"
import (
"errors"
"io"
"io/ioutil"
"math"
)
var (
errMissingPaddingByte = errors.New("riff: missing padding byte")
errMissingRIFFChunkHeader = errors.New("riff: missing RIFF chunk header")
errListSubchunkTooLong = errors.New("riff: list subchunk too long")
errShortChunkData = errors.New("riff: short chunk data")
errShortChunkHeader = errors.New("riff: short chunk header")
errStaleReader = errors.New("riff: stale reader")
)
// u32 decodes the first four bytes of b as a little-endian integer.
func u32(b []byte) uint32 {
return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
}
const chunkHeaderSize = 8
// FourCC is a four character code.
type FourCC [4]byte
// LIST is the "LIST" FourCC.
var LIST = FourCC{'L', 'I', 'S', 'T'}
// NewReader returns the RIFF stream's form type, such as "AVI " or "WAVE", and
// its chunks as a *Reader.
func NewReader(r io.Reader) (formType FourCC, data *Reader, err error) {
var buf [chunkHeaderSize]byte
if _, err := io.ReadFull(r, buf[:]); err != nil {
if err == io.EOF || err == io.ErrUnexpectedEOF {
err = errMissingRIFFChunkHeader
}
return FourCC{}, nil, err
}
if buf[0] != 'R' || buf[1] != 'I' || buf[2] != 'F' || buf[3] != 'F' {
return FourCC{}, nil, errMissingRIFFChunkHeader
}
return NewListReader(u32(buf[4:]), r)
}
// NewListReader returns a LIST chunk's list type, such as "movi" or "wavl",
// and its chunks as a *Reader.
func NewListReader(chunkLen uint32, chunkData io.Reader) (listType FourCC, data *Reader, err error) {
if chunkLen < 4 {
return FourCC{}, nil, errShortChunkData
}
z := &Reader{r: chunkData}
if _, err := io.ReadFull(chunkData, z.buf[:4]); err != nil {
if err == io.EOF || err == io.ErrUnexpectedEOF {
err = errShortChunkData
}
return FourCC{}, nil, err
}
z.totalLen = chunkLen - 4
return FourCC{z.buf[0], z.buf[1], z.buf[2], z.buf[3]}, z, nil
}
// Reader reads chunks from an underlying io.Reader.
type Reader struct {
r io.Reader
err error
totalLen uint32
chunkLen uint32
chunkReader *chunkReader
buf [chunkHeaderSize]byte
padded bool
}
// Next returns the next chunk's ID, length and data. It returns io.EOF if there
// are no more chunks. The io.Reader returned becomes stale after the next Next
// call, and should no longer be used.
//
// It is valid to call Next even if all of the previous chunk's data has not
// been read.
func (z *Reader) Next() (chunkID FourCC, chunkLen uint32, chunkData io.Reader, err error) {
if z.err != nil {
return FourCC{}, 0, nil, z.err
}
// Drain the rest of the previous chunk.
if z.chunkLen != 0 {
want := z.chunkLen
var got int64
got, z.err = io.Copy(ioutil.Discard, z.chunkReader)
if z.err == nil && uint32(got) != want {
z.err = errShortChunkData
}
if z.err != nil {
return FourCC{}, 0, nil, z.err
}
}
z.chunkReader = nil
if z.padded {
if z.totalLen == 0 {
z.err = errListSubchunkTooLong
return FourCC{}, 0, nil, z.err
}
z.totalLen--
_, z.err = io.ReadFull(z.r, z.buf[:1])
if z.err != nil {
if z.err == io.EOF {
z.err = errMissingPaddingByte
}
return FourCC{}, 0, nil, z.err
}
}
// We are done if we have no more data.
if z.totalLen == 0 {
z.err = io.EOF
return FourCC{}, 0, nil, z.err
}
// Read the next chunk header.
if z.totalLen < chunkHeaderSize {
z.err = errShortChunkHeader
return FourCC{}, 0, nil, z.err
}
z.totalLen -= chunkHeaderSize
if _, z.err = io.ReadFull(z.r, z.buf[:chunkHeaderSize]); z.err != nil {
if z.err == io.EOF || z.err == io.ErrUnexpectedEOF {
z.err = errShortChunkHeader
}
return FourCC{}, 0, nil, z.err
}
chunkID = FourCC{z.buf[0], z.buf[1], z.buf[2], z.buf[3]}
z.chunkLen = u32(z.buf[4:])
if z.chunkLen > z.totalLen {
z.err = errListSubchunkTooLong
return FourCC{}, 0, nil, z.err
}
z.padded = z.chunkLen&1 == 1
z.chunkReader = &chunkReader{z}
return chunkID, z.chunkLen, z.chunkReader, nil
}
type chunkReader struct {
z *Reader
}
func (c *chunkReader) Read(p []byte) (int, error) {
if c != c.z.chunkReader {
return 0, errStaleReader
}
z := c.z
if z.err != nil {
if z.err == io.EOF {
return 0, errStaleReader
}
return 0, z.err
}
n := int(z.chunkLen)
if n == 0 {
return 0, io.EOF
}
if n < 0 {
// Converting uint32 to int overflowed.
n = math.MaxInt32
}
if n > len(p) {
n = len(p)
}
n, err := z.r.Read(p[:n])
z.totalLen -= uint32(n)
z.chunkLen -= uint32(n)
if err != io.EOF {
z.err = err
}
return n, err
}

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@ -1,403 +0,0 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package vp8 implements a decoder for the VP8 lossy image format.
//
// The VP8 specification is RFC 6386.
package vp8 // import "golang.org/x/image/vp8"
// This file implements the top-level decoding algorithm.
import (
"errors"
"image"
"io"
)
// limitReader wraps an io.Reader to read at most n bytes from it.
type limitReader struct {
r io.Reader
n int
}
// ReadFull reads exactly len(p) bytes into p.
func (r *limitReader) ReadFull(p []byte) error {
if len(p) > r.n {
return io.ErrUnexpectedEOF
}
n, err := io.ReadFull(r.r, p)
r.n -= n
return err
}
// FrameHeader is a frame header, as specified in section 9.1.
type FrameHeader struct {
KeyFrame bool
VersionNumber uint8
ShowFrame bool
FirstPartitionLen uint32
Width int
Height int
XScale uint8
YScale uint8
}
const (
nSegment = 4
nSegmentProb = 3
)
// segmentHeader holds segment-related header information.
type segmentHeader struct {
useSegment bool
updateMap bool
relativeDelta bool
quantizer [nSegment]int8
filterStrength [nSegment]int8
prob [nSegmentProb]uint8
}
const (
nRefLFDelta = 4
nModeLFDelta = 4
)
// filterHeader holds filter-related header information.
type filterHeader struct {
simple bool
level int8
sharpness uint8
useLFDelta bool
refLFDelta [nRefLFDelta]int8
modeLFDelta [nModeLFDelta]int8
perSegmentLevel [nSegment]int8
}
// mb is the per-macroblock decode state. A decoder maintains mbw+1 of these
// as it is decoding macroblocks left-to-right and top-to-bottom: mbw for the
// macroblocks in the row above, and one for the macroblock to the left.
type mb struct {
// pred is the predictor mode for the 4 bottom or right 4x4 luma regions.
pred [4]uint8
// nzMask is a mask of 8 bits: 4 for the bottom or right 4x4 luma regions,
// and 2 + 2 for the bottom or right 4x4 chroma regions. A 1 bit indicates
// that that region has non-zero coefficients.
nzMask uint8
// nzY16 is a 0/1 value that is 1 if the macroblock used Y16 prediction and
// had non-zero coefficients.
nzY16 uint8
}
// Decoder decodes VP8 bitstreams into frames. Decoding one frame consists of
// calling Init, DecodeFrameHeader and then DecodeFrame in that order.
// A Decoder can be re-used to decode multiple frames.
type Decoder struct {
// r is the input bitsream.
r limitReader
// scratch is a scratch buffer.
scratch [8]byte
// img is the YCbCr image to decode into.
img *image.YCbCr
// mbw and mbh are the number of 16x16 macroblocks wide and high the image is.
mbw, mbh int
// frameHeader is the frame header. When decoding multiple frames,
// frames that aren't key frames will inherit the Width, Height,
// XScale and YScale of the most recent key frame.
frameHeader FrameHeader
// Other headers.
segmentHeader segmentHeader
filterHeader filterHeader
// The image data is divided into a number of independent partitions.
// There is 1 "first partition" and between 1 and 8 "other partitions"
// for coefficient data.
fp partition
op [8]partition
nOP int
// Quantization factors.
quant [nSegment]quant
// DCT/WHT coefficient decoding probabilities.
tokenProb [nPlane][nBand][nContext][nProb]uint8
useSkipProb bool
skipProb uint8
// Loop filter parameters.
filterParams [nSegment][2]filterParam
perMBFilterParams []filterParam
// The eight fields below relate to the current macroblock being decoded.
//
// Segment-based adjustments.
segment int
// Per-macroblock state for the macroblock immediately left of and those
// macroblocks immediately above the current macroblock.
leftMB mb
upMB []mb
// Bitmasks for which 4x4 regions of coeff contain non-zero coefficients.
nzDCMask, nzACMask uint32
// Predictor modes.
usePredY16 bool // The libwebp C code calls this !is_i4x4_.
predY16 uint8
predC8 uint8
predY4 [4][4]uint8
// The two fields below form a workspace for reconstructing a macroblock.
// Their specific sizes are documented in reconstruct.go.
coeff [1*16*16 + 2*8*8 + 1*4*4]int16
ybr [1 + 16 + 1 + 8][32]uint8
}
// NewDecoder returns a new Decoder.
func NewDecoder() *Decoder {
return &Decoder{}
}
// Init initializes the decoder to read at most n bytes from r.
func (d *Decoder) Init(r io.Reader, n int) {
d.r = limitReader{r, n}
}
// DecodeFrameHeader decodes the frame header.
func (d *Decoder) DecodeFrameHeader() (fh FrameHeader, err error) {
// All frame headers are at least 3 bytes long.
b := d.scratch[:3]
if err = d.r.ReadFull(b); err != nil {
return
}
d.frameHeader.KeyFrame = (b[0] & 1) == 0
d.frameHeader.VersionNumber = (b[0] >> 1) & 7
d.frameHeader.ShowFrame = (b[0]>>4)&1 == 1
d.frameHeader.FirstPartitionLen = uint32(b[0])>>5 | uint32(b[1])<<3 | uint32(b[2])<<11
if !d.frameHeader.KeyFrame {
return d.frameHeader, nil
}
// Frame headers for key frames are an additional 7 bytes long.
b = d.scratch[:7]
if err = d.r.ReadFull(b); err != nil {
return
}
// Check the magic sync code.
if b[0] != 0x9d || b[1] != 0x01 || b[2] != 0x2a {
err = errors.New("vp8: invalid format")
return
}
d.frameHeader.Width = int(b[4]&0x3f)<<8 | int(b[3])
d.frameHeader.Height = int(b[6]&0x3f)<<8 | int(b[5])
d.frameHeader.XScale = b[4] >> 6
d.frameHeader.YScale = b[6] >> 6
d.mbw = (d.frameHeader.Width + 0x0f) >> 4
d.mbh = (d.frameHeader.Height + 0x0f) >> 4
d.segmentHeader = segmentHeader{
prob: [3]uint8{0xff, 0xff, 0xff},
}
d.tokenProb = defaultTokenProb
d.segment = 0
return d.frameHeader, nil
}
// ensureImg ensures that d.img is large enough to hold the decoded frame.
func (d *Decoder) ensureImg() {
if d.img != nil {
p0, p1 := d.img.Rect.Min, d.img.Rect.Max
if p0.X == 0 && p0.Y == 0 && p1.X >= 16*d.mbw && p1.Y >= 16*d.mbh {
return
}
}
m := image.NewYCbCr(image.Rect(0, 0, 16*d.mbw, 16*d.mbh), image.YCbCrSubsampleRatio420)
d.img = m.SubImage(image.Rect(0, 0, d.frameHeader.Width, d.frameHeader.Height)).(*image.YCbCr)
d.perMBFilterParams = make([]filterParam, d.mbw*d.mbh)
d.upMB = make([]mb, d.mbw)
}
// parseSegmentHeader parses the segment header, as specified in section 9.3.
func (d *Decoder) parseSegmentHeader() {
d.segmentHeader.useSegment = d.fp.readBit(uniformProb)
if !d.segmentHeader.useSegment {
d.segmentHeader.updateMap = false
return
}
d.segmentHeader.updateMap = d.fp.readBit(uniformProb)
if d.fp.readBit(uniformProb) {
d.segmentHeader.relativeDelta = !d.fp.readBit(uniformProb)
for i := range d.segmentHeader.quantizer {
d.segmentHeader.quantizer[i] = int8(d.fp.readOptionalInt(uniformProb, 7))
}
for i := range d.segmentHeader.filterStrength {
d.segmentHeader.filterStrength[i] = int8(d.fp.readOptionalInt(uniformProb, 6))
}
}
if !d.segmentHeader.updateMap {
return
}
for i := range d.segmentHeader.prob {
if d.fp.readBit(uniformProb) {
d.segmentHeader.prob[i] = uint8(d.fp.readUint(uniformProb, 8))
} else {
d.segmentHeader.prob[i] = 0xff
}
}
}
// parseFilterHeader parses the filter header, as specified in section 9.4.
func (d *Decoder) parseFilterHeader() {
d.filterHeader.simple = d.fp.readBit(uniformProb)
d.filterHeader.level = int8(d.fp.readUint(uniformProb, 6))
d.filterHeader.sharpness = uint8(d.fp.readUint(uniformProb, 3))
d.filterHeader.useLFDelta = d.fp.readBit(uniformProb)
if d.filterHeader.useLFDelta && d.fp.readBit(uniformProb) {
for i := range d.filterHeader.refLFDelta {
d.filterHeader.refLFDelta[i] = int8(d.fp.readOptionalInt(uniformProb, 6))
}
for i := range d.filterHeader.modeLFDelta {
d.filterHeader.modeLFDelta[i] = int8(d.fp.readOptionalInt(uniformProb, 6))
}
}
if d.filterHeader.level == 0 {
return
}
if d.segmentHeader.useSegment {
for i := range d.filterHeader.perSegmentLevel {
strength := d.segmentHeader.filterStrength[i]
if d.segmentHeader.relativeDelta {
strength += d.filterHeader.level
}
d.filterHeader.perSegmentLevel[i] = strength
}
} else {
d.filterHeader.perSegmentLevel[0] = d.filterHeader.level
}
d.computeFilterParams()
}
// parseOtherPartitions parses the other partitions, as specified in section 9.5.
func (d *Decoder) parseOtherPartitions() error {
const maxNOP = 1 << 3
var partLens [maxNOP]int
d.nOP = 1 << d.fp.readUint(uniformProb, 2)
// The final partition length is implied by the the remaining chunk data
// (d.r.n) and the other d.nOP-1 partition lengths. Those d.nOP-1 partition
// lengths are stored as 24-bit uints, i.e. up to 16 MiB per partition.
n := 3 * (d.nOP - 1)
partLens[d.nOP-1] = d.r.n - n
if partLens[d.nOP-1] < 0 {
return io.ErrUnexpectedEOF
}
if n > 0 {
buf := make([]byte, n)
if err := d.r.ReadFull(buf); err != nil {
return err
}
for i := 0; i < d.nOP-1; i++ {
pl := int(buf[3*i+0]) | int(buf[3*i+1])<<8 | int(buf[3*i+2])<<16
if pl > partLens[d.nOP-1] {
return io.ErrUnexpectedEOF
}
partLens[i] = pl
partLens[d.nOP-1] -= pl
}
}
// We check if the final partition length can also fit into a 24-bit uint.
// Strictly speaking, this isn't part of the spec, but it guards against a
// malicious WEBP image that is too large to ReadFull the encoded DCT
// coefficients into memory, whether that's because the actual WEBP file is
// too large, or whether its RIFF metadata lists too large a chunk.
if 1<<24 <= partLens[d.nOP-1] {
return errors.New("vp8: too much data to decode")
}
buf := make([]byte, d.r.n)
if err := d.r.ReadFull(buf); err != nil {
return err
}
for i, pl := range partLens {
if i == d.nOP {
break
}
d.op[i].init(buf[:pl])
buf = buf[pl:]
}
return nil
}
// parseOtherHeaders parses header information other than the frame header.
func (d *Decoder) parseOtherHeaders() error {
// Initialize and parse the first partition.
firstPartition := make([]byte, d.frameHeader.FirstPartitionLen)
if err := d.r.ReadFull(firstPartition); err != nil {
return err
}
d.fp.init(firstPartition)
if d.frameHeader.KeyFrame {
// Read and ignore the color space and pixel clamp values. They are
// specified in section 9.2, but are unimplemented.
d.fp.readBit(uniformProb)
d.fp.readBit(uniformProb)
}
d.parseSegmentHeader()
d.parseFilterHeader()
if err := d.parseOtherPartitions(); err != nil {
return err
}
d.parseQuant()
if !d.frameHeader.KeyFrame {
// Golden and AltRef frames are specified in section 9.7.
// TODO(nigeltao): implement. Note that they are only used for video, not still images.
return errors.New("vp8: Golden / AltRef frames are not implemented")
}
// Read and ignore the refreshLastFrameBuffer bit, specified in section 9.8.
// It applies only to video, and not still images.
d.fp.readBit(uniformProb)
d.parseTokenProb()
d.useSkipProb = d.fp.readBit(uniformProb)
if d.useSkipProb {
d.skipProb = uint8(d.fp.readUint(uniformProb, 8))
}
if d.fp.unexpectedEOF {
return io.ErrUnexpectedEOF
}
return nil
}
// DecodeFrame decodes the frame and returns it as an YCbCr image.
// The image's contents are valid up until the next call to Decoder.Init.
func (d *Decoder) DecodeFrame() (*image.YCbCr, error) {
d.ensureImg()
if err := d.parseOtherHeaders(); err != nil {
return nil, err
}
// Reconstruct the rows.
for mbx := 0; mbx < d.mbw; mbx++ {
d.upMB[mbx] = mb{}
}
for mby := 0; mby < d.mbh; mby++ {
d.leftMB = mb{}
for mbx := 0; mbx < d.mbw; mbx++ {
skip := d.reconstruct(mbx, mby)
fs := d.filterParams[d.segment][btou(!d.usePredY16)]
fs.inner = fs.inner || !skip
d.perMBFilterParams[d.mbw*mby+mbx] = fs
}
}
if d.fp.unexpectedEOF {
return nil, io.ErrUnexpectedEOF
}
for i := 0; i < d.nOP; i++ {
if d.op[i].unexpectedEOF {
return nil, io.ErrUnexpectedEOF
}
}
// Apply the loop filter.
//
// Even if we are using per-segment levels, section 15 says that "loop
// filtering must be skipped entirely if loop_filter_level at either the
// frame header level or macroblock override level is 0".
if d.filterHeader.level != 0 {
if d.filterHeader.simple {
d.simpleFilter()
} else {
d.normalFilter()
}
}
return d.img, nil
}

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// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vp8
// filter2 modifies a 2-pixel wide or 2-pixel high band along an edge.
func filter2(pix []byte, level, index, iStep, jStep int) {
for n := 16; n > 0; n, index = n-1, index+iStep {
p1 := int(pix[index-2*jStep])
p0 := int(pix[index-1*jStep])
q0 := int(pix[index+0*jStep])
q1 := int(pix[index+1*jStep])
if abs(p0-q0)<<1+abs(p1-q1)>>1 > level {
continue
}
a := 3*(q0-p0) + clamp127(p1-q1)
a1 := clamp15((a + 4) >> 3)
a2 := clamp15((a + 3) >> 3)
pix[index-1*jStep] = clamp255(p0 + a2)
pix[index+0*jStep] = clamp255(q0 - a1)
}
}
// filter246 modifies a 2-, 4- or 6-pixel wide or high band along an edge.
func filter246(pix []byte, n, level, ilevel, hlevel, index, iStep, jStep int, fourNotSix bool) {
for ; n > 0; n, index = n-1, index+iStep {
p3 := int(pix[index-4*jStep])
p2 := int(pix[index-3*jStep])
p1 := int(pix[index-2*jStep])
p0 := int(pix[index-1*jStep])
q0 := int(pix[index+0*jStep])
q1 := int(pix[index+1*jStep])
q2 := int(pix[index+2*jStep])
q3 := int(pix[index+3*jStep])
if abs(p0-q0)<<1+abs(p1-q1)>>1 > level {
continue
}
if abs(p3-p2) > ilevel ||
abs(p2-p1) > ilevel ||
abs(p1-p0) > ilevel ||
abs(q1-q0) > ilevel ||
abs(q2-q1) > ilevel ||
abs(q3-q2) > ilevel {
continue
}
if abs(p1-p0) > hlevel || abs(q1-q0) > hlevel {
// Filter 2 pixels.
a := 3*(q0-p0) + clamp127(p1-q1)
a1 := clamp15((a + 4) >> 3)
a2 := clamp15((a + 3) >> 3)
pix[index-1*jStep] = clamp255(p0 + a2)
pix[index+0*jStep] = clamp255(q0 - a1)
} else if fourNotSix {
// Filter 4 pixels.
a := 3 * (q0 - p0)
a1 := clamp15((a + 4) >> 3)
a2 := clamp15((a + 3) >> 3)
a3 := (a1 + 1) >> 1
pix[index-2*jStep] = clamp255(p1 + a3)
pix[index-1*jStep] = clamp255(p0 + a2)
pix[index+0*jStep] = clamp255(q0 - a1)
pix[index+1*jStep] = clamp255(q1 - a3)
} else {
// Filter 6 pixels.
a := clamp127(3*(q0-p0) + clamp127(p1-q1))
a1 := (27*a + 63) >> 7
a2 := (18*a + 63) >> 7
a3 := (9*a + 63) >> 7
pix[index-3*jStep] = clamp255(p2 + a3)
pix[index-2*jStep] = clamp255(p1 + a2)
pix[index-1*jStep] = clamp255(p0 + a1)
pix[index+0*jStep] = clamp255(q0 - a1)
pix[index+1*jStep] = clamp255(q1 - a2)
pix[index+2*jStep] = clamp255(q2 - a3)
}
}
}
// simpleFilter implements the simple filter, as specified in section 15.2.
func (d *Decoder) simpleFilter() {
for mby := 0; mby < d.mbh; mby++ {
for mbx := 0; mbx < d.mbw; mbx++ {
f := d.perMBFilterParams[d.mbw*mby+mbx]
if f.level == 0 {
continue
}
l := int(f.level)
yIndex := (mby*d.img.YStride + mbx) * 16
if mbx > 0 {
filter2(d.img.Y, l+4, yIndex, d.img.YStride, 1)
}
if f.inner {
filter2(d.img.Y, l, yIndex+0x4, d.img.YStride, 1)
filter2(d.img.Y, l, yIndex+0x8, d.img.YStride, 1)
filter2(d.img.Y, l, yIndex+0xc, d.img.YStride, 1)
}
if mby > 0 {
filter2(d.img.Y, l+4, yIndex, 1, d.img.YStride)
}
if f.inner {
filter2(d.img.Y, l, yIndex+d.img.YStride*0x4, 1, d.img.YStride)
filter2(d.img.Y, l, yIndex+d.img.YStride*0x8, 1, d.img.YStride)
filter2(d.img.Y, l, yIndex+d.img.YStride*0xc, 1, d.img.YStride)
}
}
}
}
// normalFilter implements the normal filter, as specified in section 15.3.
func (d *Decoder) normalFilter() {
for mby := 0; mby < d.mbh; mby++ {
for mbx := 0; mbx < d.mbw; mbx++ {
f := d.perMBFilterParams[d.mbw*mby+mbx]
if f.level == 0 {
continue
}
l, il, hl := int(f.level), int(f.ilevel), int(f.hlevel)
yIndex := (mby*d.img.YStride + mbx) * 16
cIndex := (mby*d.img.CStride + mbx) * 8
if mbx > 0 {
filter246(d.img.Y, 16, l+4, il, hl, yIndex, d.img.YStride, 1, false)
filter246(d.img.Cb, 8, l+4, il, hl, cIndex, d.img.CStride, 1, false)
filter246(d.img.Cr, 8, l+4, il, hl, cIndex, d.img.CStride, 1, false)
}
if f.inner {
filter246(d.img.Y, 16, l, il, hl, yIndex+0x4, d.img.YStride, 1, true)
filter246(d.img.Y, 16, l, il, hl, yIndex+0x8, d.img.YStride, 1, true)
filter246(d.img.Y, 16, l, il, hl, yIndex+0xc, d.img.YStride, 1, true)
filter246(d.img.Cb, 8, l, il, hl, cIndex+0x4, d.img.CStride, 1, true)
filter246(d.img.Cr, 8, l, il, hl, cIndex+0x4, d.img.CStride, 1, true)
}
if mby > 0 {
filter246(d.img.Y, 16, l+4, il, hl, yIndex, 1, d.img.YStride, false)
filter246(d.img.Cb, 8, l+4, il, hl, cIndex, 1, d.img.CStride, false)
filter246(d.img.Cr, 8, l+4, il, hl, cIndex, 1, d.img.CStride, false)
}
if f.inner {
filter246(d.img.Y, 16, l, il, hl, yIndex+d.img.YStride*0x4, 1, d.img.YStride, true)
filter246(d.img.Y, 16, l, il, hl, yIndex+d.img.YStride*0x8, 1, d.img.YStride, true)
filter246(d.img.Y, 16, l, il, hl, yIndex+d.img.YStride*0xc, 1, d.img.YStride, true)
filter246(d.img.Cb, 8, l, il, hl, cIndex+d.img.CStride*0x4, 1, d.img.CStride, true)
filter246(d.img.Cr, 8, l, il, hl, cIndex+d.img.CStride*0x4, 1, d.img.CStride, true)
}
}
}
}
// filterParam holds the loop filter parameters for a macroblock.
type filterParam struct {
// The first three fields are thresholds used by the loop filter to smooth
// over the edges and interior of a macroblock. level is used by both the
// simple and normal filters. The inner level and high edge variance level
// are only used by the normal filter.
level, ilevel, hlevel uint8
// inner is whether the inner loop filter cannot be optimized out as a
// no-op for this particular macroblock.
inner bool
}
// computeFilterParams computes the loop filter parameters, as specified in
// section 15.4.
func (d *Decoder) computeFilterParams() {
for i := range d.filterParams {
baseLevel := d.filterHeader.level
if d.segmentHeader.useSegment {
baseLevel = d.segmentHeader.filterStrength[i]
if d.segmentHeader.relativeDelta {
baseLevel += d.filterHeader.level
}
}
for j := range d.filterParams[i] {
p := &d.filterParams[i][j]
p.inner = j != 0
level := baseLevel
if d.filterHeader.useLFDelta {
// The libwebp C code has a "TODO: only CURRENT is handled for now."
level += d.filterHeader.refLFDelta[0]
if j != 0 {
level += d.filterHeader.modeLFDelta[0]
}
}
if level <= 0 {
p.level = 0
continue
}
if level > 63 {
level = 63
}
ilevel := level
if d.filterHeader.sharpness > 0 {
if d.filterHeader.sharpness > 4 {
ilevel >>= 2
} else {
ilevel >>= 1
}
if x := int8(9 - d.filterHeader.sharpness); ilevel > x {
ilevel = x
}
}
if ilevel < 1 {
ilevel = 1
}
p.ilevel = uint8(ilevel)
p.level = uint8(2*level + ilevel)
if d.frameHeader.KeyFrame {
if level < 15 {
p.hlevel = 0
} else if level < 40 {
p.hlevel = 1
} else {
p.hlevel = 2
}
} else {
if level < 15 {
p.hlevel = 0
} else if level < 20 {
p.hlevel = 1
} else if level < 40 {
p.hlevel = 2
} else {
p.hlevel = 3
}
}
}
}
}
// intSize is either 32 or 64.
const intSize = 32 << (^uint(0) >> 63)
func abs(x int) int {
// m := -1 if x < 0. m := 0 otherwise.
m := x >> (intSize - 1)
// In two's complement representation, the negative number
// of any number (except the smallest one) can be computed
// by flipping all the bits and add 1. This is faster than
// code with a branch.
// See Hacker's Delight, section 2-4.
return (x ^ m) - m
}
func clamp15(x int) int {
if x < -16 {
return -16
}
if x > 15 {
return 15
}
return x
}
func clamp127(x int) int {
if x < -128 {
return -128
}
if x > 127 {
return 127
}
return x
}
func clamp255(x int) uint8 {
if x < 0 {
return 0
}
if x > 255 {
return 255
}
return uint8(x)
}

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@ -1,98 +0,0 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vp8
// This file implements the inverse Discrete Cosine Transform and the inverse
// Walsh Hadamard Transform (WHT), as specified in sections 14.3 and 14.4.
func clip8(i int32) uint8 {
if i < 0 {
return 0
}
if i > 255 {
return 255
}
return uint8(i)
}
func (z *Decoder) inverseDCT4(y, x, coeffBase int) {
const (
c1 = 85627 // 65536 * cos(pi/8) * sqrt(2).
c2 = 35468 // 65536 * sin(pi/8) * sqrt(2).
)
var m [4][4]int32
for i := 0; i < 4; i++ {
a := int32(z.coeff[coeffBase+0]) + int32(z.coeff[coeffBase+8])
b := int32(z.coeff[coeffBase+0]) - int32(z.coeff[coeffBase+8])
c := (int32(z.coeff[coeffBase+4])*c2)>>16 - (int32(z.coeff[coeffBase+12])*c1)>>16
d := (int32(z.coeff[coeffBase+4])*c1)>>16 + (int32(z.coeff[coeffBase+12])*c2)>>16
m[i][0] = a + d
m[i][1] = b + c
m[i][2] = b - c
m[i][3] = a - d
coeffBase++
}
for j := 0; j < 4; j++ {
dc := m[0][j] + 4
a := dc + m[2][j]
b := dc - m[2][j]
c := (m[1][j]*c2)>>16 - (m[3][j]*c1)>>16
d := (m[1][j]*c1)>>16 + (m[3][j]*c2)>>16
z.ybr[y+j][x+0] = clip8(int32(z.ybr[y+j][x+0]) + (a+d)>>3)
z.ybr[y+j][x+1] = clip8(int32(z.ybr[y+j][x+1]) + (b+c)>>3)
z.ybr[y+j][x+2] = clip8(int32(z.ybr[y+j][x+2]) + (b-c)>>3)
z.ybr[y+j][x+3] = clip8(int32(z.ybr[y+j][x+3]) + (a-d)>>3)
}
}
func (z *Decoder) inverseDCT4DCOnly(y, x, coeffBase int) {
dc := (int32(z.coeff[coeffBase+0]) + 4) >> 3
for j := 0; j < 4; j++ {
for i := 0; i < 4; i++ {
z.ybr[y+j][x+i] = clip8(int32(z.ybr[y+j][x+i]) + dc)
}
}
}
func (z *Decoder) inverseDCT8(y, x, coeffBase int) {
z.inverseDCT4(y+0, x+0, coeffBase+0*16)
z.inverseDCT4(y+0, x+4, coeffBase+1*16)
z.inverseDCT4(y+4, x+0, coeffBase+2*16)
z.inverseDCT4(y+4, x+4, coeffBase+3*16)
}
func (z *Decoder) inverseDCT8DCOnly(y, x, coeffBase int) {
z.inverseDCT4DCOnly(y+0, x+0, coeffBase+0*16)
z.inverseDCT4DCOnly(y+0, x+4, coeffBase+1*16)
z.inverseDCT4DCOnly(y+4, x+0, coeffBase+2*16)
z.inverseDCT4DCOnly(y+4, x+4, coeffBase+3*16)
}
func (d *Decoder) inverseWHT16() {
var m [16]int32
for i := 0; i < 4; i++ {
a0 := int32(d.coeff[384+0+i]) + int32(d.coeff[384+12+i])
a1 := int32(d.coeff[384+4+i]) + int32(d.coeff[384+8+i])
a2 := int32(d.coeff[384+4+i]) - int32(d.coeff[384+8+i])
a3 := int32(d.coeff[384+0+i]) - int32(d.coeff[384+12+i])
m[0+i] = a0 + a1
m[8+i] = a0 - a1
m[4+i] = a3 + a2
m[12+i] = a3 - a2
}
out := 0
for i := 0; i < 4; i++ {
dc := m[0+i*4] + 3
a0 := dc + m[3+i*4]
a1 := m[1+i*4] + m[2+i*4]
a2 := m[1+i*4] - m[2+i*4]
a3 := dc - m[3+i*4]
d.coeff[out+0] = int16((a0 + a1) >> 3)
d.coeff[out+16] = int16((a3 + a2) >> 3)
d.coeff[out+32] = int16((a0 - a1) >> 3)
d.coeff[out+48] = int16((a3 - a2) >> 3)
out += 64
}
}

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@ -1,129 +0,0 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vp8
// Each VP8 frame consists of between 2 and 9 bitstream partitions.
// Each partition is byte-aligned and is independently arithmetic-encoded.
//
// This file implements decoding a partition's bitstream, as specified in
// chapter 7. The implementation follows libwebp's approach instead of the
// specification's reference C implementation. For example, we use a look-up
// table instead of a for loop to recalibrate the encoded range.
var (
lutShift = [127]uint8{
7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
}
lutRangeM1 = [127]uint8{
127,
127, 191,
127, 159, 191, 223,
127, 143, 159, 175, 191, 207, 223, 239,
127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, 239, 247,
127, 131, 135, 139, 143, 147, 151, 155, 159, 163, 167, 171, 175, 179, 183, 187,
191, 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239, 243, 247, 251,
127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157,
159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189,
191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221,
223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253,
}
)
// uniformProb represents a 50% probability that the next bit is 0.
const uniformProb = 128
// partition holds arithmetic-coded bits.
type partition struct {
// buf is the input bytes.
buf []byte
// r is how many of buf's bytes have been consumed.
r int
// rangeM1 is range minus 1, where range is in the arithmetic coding sense,
// not the Go language sense.
rangeM1 uint32
// bits and nBits hold those bits shifted out of buf but not yet consumed.
bits uint32
nBits uint8
// unexpectedEOF tells whether we tried to read past buf.
unexpectedEOF bool
}
// init initializes the partition.
func (p *partition) init(buf []byte) {
p.buf = buf
p.r = 0
p.rangeM1 = 254
p.bits = 0
p.nBits = 0
p.unexpectedEOF = false
}
// readBit returns the next bit.
func (p *partition) readBit(prob uint8) bool {
if p.nBits < 8 {
if p.r >= len(p.buf) {
p.unexpectedEOF = true
return false
}
// Expression split for 386 compiler.
x := uint32(p.buf[p.r])
p.bits |= x << (8 - p.nBits)
p.r++
p.nBits += 8
}
split := (p.rangeM1*uint32(prob))>>8 + 1
bit := p.bits >= split<<8
if bit {
p.rangeM1 -= split
p.bits -= split << 8
} else {
p.rangeM1 = split - 1
}
if p.rangeM1 < 127 {
shift := lutShift[p.rangeM1]
p.rangeM1 = uint32(lutRangeM1[p.rangeM1])
p.bits <<= shift
p.nBits -= shift
}
return bit
}
// readUint returns the next n-bit unsigned integer.
func (p *partition) readUint(prob, n uint8) uint32 {
var u uint32
for n > 0 {
n--
if p.readBit(prob) {
u |= 1 << n
}
}
return u
}
// readInt returns the next n-bit signed integer.
func (p *partition) readInt(prob, n uint8) int32 {
u := p.readUint(prob, n)
b := p.readBit(prob)
if b {
return -int32(u)
}
return int32(u)
}
// readOptionalInt returns the next n-bit signed integer in an encoding
// where the likely result is zero.
func (p *partition) readOptionalInt(prob, n uint8) int32 {
if !p.readBit(prob) {
return 0
}
return p.readInt(prob, n)
}

201
vendor/golang.org/x/image/vp8/pred.go generated vendored
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@ -1,201 +0,0 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vp8
// This file implements parsing the predictor modes, as specified in chapter
// 11.
func (d *Decoder) parsePredModeY16(mbx int) {
var p uint8
if !d.fp.readBit(156) {
if !d.fp.readBit(163) {
p = predDC
} else {
p = predVE
}
} else if !d.fp.readBit(128) {
p = predHE
} else {
p = predTM
}
for i := 0; i < 4; i++ {
d.upMB[mbx].pred[i] = p
d.leftMB.pred[i] = p
}
d.predY16 = p
}
func (d *Decoder) parsePredModeC8() {
if !d.fp.readBit(142) {
d.predC8 = predDC
} else if !d.fp.readBit(114) {
d.predC8 = predVE
} else if !d.fp.readBit(183) {
d.predC8 = predHE
} else {
d.predC8 = predTM
}
}
func (d *Decoder) parsePredModeY4(mbx int) {
for j := 0; j < 4; j++ {
p := d.leftMB.pred[j]
for i := 0; i < 4; i++ {
prob := &predProb[d.upMB[mbx].pred[i]][p]
if !d.fp.readBit(prob[0]) {
p = predDC
} else if !d.fp.readBit(prob[1]) {
p = predTM
} else if !d.fp.readBit(prob[2]) {
p = predVE
} else if !d.fp.readBit(prob[3]) {
if !d.fp.readBit(prob[4]) {
p = predHE
} else if !d.fp.readBit(prob[5]) {
p = predRD
} else {
p = predVR
}
} else if !d.fp.readBit(prob[6]) {
p = predLD
} else if !d.fp.readBit(prob[7]) {
p = predVL
} else if !d.fp.readBit(prob[8]) {
p = predHD
} else {
p = predHU
}
d.predY4[j][i] = p
d.upMB[mbx].pred[i] = p
}
d.leftMB.pred[j] = p
}
}
// predProb are the probabilities to decode a 4x4 region's predictor mode given
// the predictor modes of the regions above and left of it.
// These values are specified in section 11.5.
var predProb = [nPred][nPred][9]uint8{
{
{231, 120, 48, 89, 115, 113, 120, 152, 112},
{152, 179, 64, 126, 170, 118, 46, 70, 95},
{175, 69, 143, 80, 85, 82, 72, 155, 103},
{56, 58, 10, 171, 218, 189, 17, 13, 152},
{114, 26, 17, 163, 44, 195, 21, 10, 173},
{121, 24, 80, 195, 26, 62, 44, 64, 85},
{144, 71, 10, 38, 171, 213, 144, 34, 26},
{170, 46, 55, 19, 136, 160, 33, 206, 71},
{63, 20, 8, 114, 114, 208, 12, 9, 226},
{81, 40, 11, 96, 182, 84, 29, 16, 36},
},
{
{134, 183, 89, 137, 98, 101, 106, 165, 148},
{72, 187, 100, 130, 157, 111, 32, 75, 80},
{66, 102, 167, 99, 74, 62, 40, 234, 128},
{41, 53, 9, 178, 241, 141, 26, 8, 107},
{74, 43, 26, 146, 73, 166, 49, 23, 157},
{65, 38, 105, 160, 51, 52, 31, 115, 128},
{104, 79, 12, 27, 217, 255, 87, 17, 7},
{87, 68, 71, 44, 114, 51, 15, 186, 23},
{47, 41, 14, 110, 182, 183, 21, 17, 194},
{66, 45, 25, 102, 197, 189, 23, 18, 22},
},
{
{88, 88, 147, 150, 42, 46, 45, 196, 205},
{43, 97, 183, 117, 85, 38, 35, 179, 61},
{39, 53, 200, 87, 26, 21, 43, 232, 171},
{56, 34, 51, 104, 114, 102, 29, 93, 77},
{39, 28, 85, 171, 58, 165, 90, 98, 64},
{34, 22, 116, 206, 23, 34, 43, 166, 73},
{107, 54, 32, 26, 51, 1, 81, 43, 31},
{68, 25, 106, 22, 64, 171, 36, 225, 114},
{34, 19, 21, 102, 132, 188, 16, 76, 124},
{62, 18, 78, 95, 85, 57, 50, 48, 51},
},
{
{193, 101, 35, 159, 215, 111, 89, 46, 111},
{60, 148, 31, 172, 219, 228, 21, 18, 111},
{112, 113, 77, 85, 179, 255, 38, 120, 114},
{40, 42, 1, 196, 245, 209, 10, 25, 109},
{88, 43, 29, 140, 166, 213, 37, 43, 154},
{61, 63, 30, 155, 67, 45, 68, 1, 209},
{100, 80, 8, 43, 154, 1, 51, 26, 71},
{142, 78, 78, 16, 255, 128, 34, 197, 171},
{41, 40, 5, 102, 211, 183, 4, 1, 221},
{51, 50, 17, 168, 209, 192, 23, 25, 82},
},
{
{138, 31, 36, 171, 27, 166, 38, 44, 229},
{67, 87, 58, 169, 82, 115, 26, 59, 179},
{63, 59, 90, 180, 59, 166, 93, 73, 154},
{40, 40, 21, 116, 143, 209, 34, 39, 175},
{47, 15, 16, 183, 34, 223, 49, 45, 183},
{46, 17, 33, 183, 6, 98, 15, 32, 183},
{57, 46, 22, 24, 128, 1, 54, 17, 37},
{65, 32, 73, 115, 28, 128, 23, 128, 205},
{40, 3, 9, 115, 51, 192, 18, 6, 223},
{87, 37, 9, 115, 59, 77, 64, 21, 47},
},
{
{104, 55, 44, 218, 9, 54, 53, 130, 226},
{64, 90, 70, 205, 40, 41, 23, 26, 57},
{54, 57, 112, 184, 5, 41, 38, 166, 213},
{30, 34, 26, 133, 152, 116, 10, 32, 134},
{39, 19, 53, 221, 26, 114, 32, 73, 255},
{31, 9, 65, 234, 2, 15, 1, 118, 73},
{75, 32, 12, 51, 192, 255, 160, 43, 51},
{88, 31, 35, 67, 102, 85, 55, 186, 85},
{56, 21, 23, 111, 59, 205, 45, 37, 192},
{55, 38, 70, 124, 73, 102, 1, 34, 98},
},
{
{125, 98, 42, 88, 104, 85, 117, 175, 82},
{95, 84, 53, 89, 128, 100, 113, 101, 45},
{75, 79, 123, 47, 51, 128, 81, 171, 1},
{57, 17, 5, 71, 102, 57, 53, 41, 49},
{38, 33, 13, 121, 57, 73, 26, 1, 85},
{41, 10, 67, 138, 77, 110, 90, 47, 114},
{115, 21, 2, 10, 102, 255, 166, 23, 6},
{101, 29, 16, 10, 85, 128, 101, 196, 26},
{57, 18, 10, 102, 102, 213, 34, 20, 43},
{117, 20, 15, 36, 163, 128, 68, 1, 26},
},
{
{102, 61, 71, 37, 34, 53, 31, 243, 192},
{69, 60, 71, 38, 73, 119, 28, 222, 37},
{68, 45, 128, 34, 1, 47, 11, 245, 171},
{62, 17, 19, 70, 146, 85, 55, 62, 70},
{37, 43, 37, 154, 100, 163, 85, 160, 1},
{63, 9, 92, 136, 28, 64, 32, 201, 85},
{75, 15, 9, 9, 64, 255, 184, 119, 16},
{86, 6, 28, 5, 64, 255, 25, 248, 1},
{56, 8, 17, 132, 137, 255, 55, 116, 128},
{58, 15, 20, 82, 135, 57, 26, 121, 40},
},
{
{164, 50, 31, 137, 154, 133, 25, 35, 218},
{51, 103, 44, 131, 131, 123, 31, 6, 158},
{86, 40, 64, 135, 148, 224, 45, 183, 128},
{22, 26, 17, 131, 240, 154, 14, 1, 209},
{45, 16, 21, 91, 64, 222, 7, 1, 197},
{56, 21, 39, 155, 60, 138, 23, 102, 213},
{83, 12, 13, 54, 192, 255, 68, 47, 28},
{85, 26, 85, 85, 128, 128, 32, 146, 171},
{18, 11, 7, 63, 144, 171, 4, 4, 246},
{35, 27, 10, 146, 174, 171, 12, 26, 128},
},
{
{190, 80, 35, 99, 180, 80, 126, 54, 45},
{85, 126, 47, 87, 176, 51, 41, 20, 32},
{101, 75, 128, 139, 118, 146, 116, 128, 85},
{56, 41, 15, 176, 236, 85, 37, 9, 62},
{71, 30, 17, 119, 118, 255, 17, 18, 138},
{101, 38, 60, 138, 55, 70, 43, 26, 142},
{146, 36, 19, 30, 171, 255, 97, 27, 20},
{138, 45, 61, 62, 219, 1, 81, 188, 64},
{32, 41, 20, 117, 151, 142, 20, 21, 163},
{112, 19, 12, 61, 195, 128, 48, 4, 24},
},
}

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@ -1,553 +0,0 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vp8
// This file implements the predicition functions, as specified in chapter 12.
//
// For each macroblock (of 1x16x16 luma and 2x8x8 chroma coefficients), the
// luma values are either predicted as one large 16x16 region or 16 separate
// 4x4 regions. The chroma values are always predicted as one 8x8 region.
//
// For 4x4 regions, the target block's predicted values (Xs) are a function of
// its previously-decoded top and left border values, as well as a number of
// pixels from the top-right:
//
// a b c d e f g h
// p X X X X
// q X X X X
// r X X X X
// s X X X X
//
// The predictor modes are:
// - DC: all Xs = (b + c + d + e + p + q + r + s + 4) / 8.
// - TM: the first X = (b + p - a), the second X = (c + p - a), and so on.
// - VE: each X = the weighted average of its column's top value and that
// value's neighbors, i.e. averages of abc, bcd, cde or def.
// - HE: similar to VE except rows instead of columns, and the final row is
// an average of r, s and s.
// - RD, VR, LD, VL, HD, HU: these diagonal modes ("Right Down", "Vertical
// Right", etc) are more complicated and are described in section 12.3.
// All Xs are clipped to the range [0, 255].
//
// For 8x8 and 16x16 regions, the target block's predicted values are a
// function of the top and left border values without the top-right overhang,
// i.e. without the 8x8 or 16x16 equivalent of f, g and h. Furthermore:
// - There are no diagonal predictor modes, only DC, TM, VE and HE.
// - The DC mode has variants for macroblocks in the top row and/or left
// column, i.e. for macroblocks with mby == 0 || mbx == 0.
// - The VE and HE modes take only the column top or row left values; they do
// not smooth that top/left value with its neighbors.
// nPred is the number of predictor modes, not including the Top/Left versions
// of the DC predictor mode.
const nPred = 10
const (
predDC = iota
predTM
predVE
predHE
predRD
predVR
predLD
predVL
predHD
predHU
predDCTop
predDCLeft
predDCTopLeft
)
func checkTopLeftPred(mbx, mby int, p uint8) uint8 {
if p != predDC {
return p
}
if mbx == 0 {
if mby == 0 {
return predDCTopLeft
}
return predDCLeft
}
if mby == 0 {
return predDCTop
}
return predDC
}
var predFunc4 = [...]func(*Decoder, int, int){
predFunc4DC,
predFunc4TM,
predFunc4VE,
predFunc4HE,
predFunc4RD,
predFunc4VR,
predFunc4LD,
predFunc4VL,
predFunc4HD,
predFunc4HU,
nil,
nil,
nil,
}
var predFunc8 = [...]func(*Decoder, int, int){
predFunc8DC,
predFunc8TM,
predFunc8VE,
predFunc8HE,
nil,
nil,
nil,
nil,
nil,
nil,
predFunc8DCTop,
predFunc8DCLeft,
predFunc8DCTopLeft,
}
var predFunc16 = [...]func(*Decoder, int, int){
predFunc16DC,
predFunc16TM,
predFunc16VE,
predFunc16HE,
nil,
nil,
nil,
nil,
nil,
nil,
predFunc16DCTop,
predFunc16DCLeft,
predFunc16DCTopLeft,
}
func predFunc4DC(z *Decoder, y, x int) {
sum := uint32(4)
for i := 0; i < 4; i++ {
sum += uint32(z.ybr[y-1][x+i])
}
for j := 0; j < 4; j++ {
sum += uint32(z.ybr[y+j][x-1])
}
avg := uint8(sum / 8)
for j := 0; j < 4; j++ {
for i := 0; i < 4; i++ {
z.ybr[y+j][x+i] = avg
}
}
}
func predFunc4TM(z *Decoder, y, x int) {
delta0 := -int32(z.ybr[y-1][x-1])
for j := 0; j < 4; j++ {
delta1 := delta0 + int32(z.ybr[y+j][x-1])
for i := 0; i < 4; i++ {
delta2 := delta1 + int32(z.ybr[y-1][x+i])
z.ybr[y+j][x+i] = uint8(clip(delta2, 0, 255))
}
}
}
func predFunc4VE(z *Decoder, y, x int) {
a := int32(z.ybr[y-1][x-1])
b := int32(z.ybr[y-1][x+0])
c := int32(z.ybr[y-1][x+1])
d := int32(z.ybr[y-1][x+2])
e := int32(z.ybr[y-1][x+3])
f := int32(z.ybr[y-1][x+4])
abc := uint8((a + 2*b + c + 2) / 4)
bcd := uint8((b + 2*c + d + 2) / 4)
cde := uint8((c + 2*d + e + 2) / 4)
def := uint8((d + 2*e + f + 2) / 4)
for j := 0; j < 4; j++ {
z.ybr[y+j][x+0] = abc
z.ybr[y+j][x+1] = bcd
z.ybr[y+j][x+2] = cde
z.ybr[y+j][x+3] = def
}
}
func predFunc4HE(z *Decoder, y, x int) {
s := int32(z.ybr[y+3][x-1])
r := int32(z.ybr[y+2][x-1])
q := int32(z.ybr[y+1][x-1])
p := int32(z.ybr[y+0][x-1])
a := int32(z.ybr[y-1][x-1])
ssr := uint8((s + 2*s + r + 2) / 4)
srq := uint8((s + 2*r + q + 2) / 4)
rqp := uint8((r + 2*q + p + 2) / 4)
apq := uint8((a + 2*p + q + 2) / 4)
for i := 0; i < 4; i++ {
z.ybr[y+0][x+i] = apq
z.ybr[y+1][x+i] = rqp
z.ybr[y+2][x+i] = srq
z.ybr[y+3][x+i] = ssr
}
}
func predFunc4RD(z *Decoder, y, x int) {
s := int32(z.ybr[y+3][x-1])
r := int32(z.ybr[y+2][x-1])
q := int32(z.ybr[y+1][x-1])
p := int32(z.ybr[y+0][x-1])
a := int32(z.ybr[y-1][x-1])
b := int32(z.ybr[y-1][x+0])
c := int32(z.ybr[y-1][x+1])
d := int32(z.ybr[y-1][x+2])
e := int32(z.ybr[y-1][x+3])
srq := uint8((s + 2*r + q + 2) / 4)
rqp := uint8((r + 2*q + p + 2) / 4)
qpa := uint8((q + 2*p + a + 2) / 4)
pab := uint8((p + 2*a + b + 2) / 4)
abc := uint8((a + 2*b + c + 2) / 4)
bcd := uint8((b + 2*c + d + 2) / 4)
cde := uint8((c + 2*d + e + 2) / 4)
z.ybr[y+0][x+0] = pab
z.ybr[y+0][x+1] = abc
z.ybr[y+0][x+2] = bcd
z.ybr[y+0][x+3] = cde
z.ybr[y+1][x+0] = qpa
z.ybr[y+1][x+1] = pab
z.ybr[y+1][x+2] = abc
z.ybr[y+1][x+3] = bcd
z.ybr[y+2][x+0] = rqp
z.ybr[y+2][x+1] = qpa
z.ybr[y+2][x+2] = pab
z.ybr[y+2][x+3] = abc
z.ybr[y+3][x+0] = srq
z.ybr[y+3][x+1] = rqp
z.ybr[y+3][x+2] = qpa
z.ybr[y+3][x+3] = pab
}
func predFunc4VR(z *Decoder, y, x int) {
r := int32(z.ybr[y+2][x-1])
q := int32(z.ybr[y+1][x-1])
p := int32(z.ybr[y+0][x-1])
a := int32(z.ybr[y-1][x-1])
b := int32(z.ybr[y-1][x+0])
c := int32(z.ybr[y-1][x+1])
d := int32(z.ybr[y-1][x+2])
e := int32(z.ybr[y-1][x+3])
ab := uint8((a + b + 1) / 2)
bc := uint8((b + c + 1) / 2)
cd := uint8((c + d + 1) / 2)
de := uint8((d + e + 1) / 2)
rqp := uint8((r + 2*q + p + 2) / 4)
qpa := uint8((q + 2*p + a + 2) / 4)
pab := uint8((p + 2*a + b + 2) / 4)
abc := uint8((a + 2*b + c + 2) / 4)
bcd := uint8((b + 2*c + d + 2) / 4)
cde := uint8((c + 2*d + e + 2) / 4)
z.ybr[y+0][x+0] = ab
z.ybr[y+0][x+1] = bc
z.ybr[y+0][x+2] = cd
z.ybr[y+0][x+3] = de
z.ybr[y+1][x+0] = pab
z.ybr[y+1][x+1] = abc
z.ybr[y+1][x+2] = bcd
z.ybr[y+1][x+3] = cde
z.ybr[y+2][x+0] = qpa
z.ybr[y+2][x+1] = ab
z.ybr[y+2][x+2] = bc
z.ybr[y+2][x+3] = cd
z.ybr[y+3][x+0] = rqp
z.ybr[y+3][x+1] = pab
z.ybr[y+3][x+2] = abc
z.ybr[y+3][x+3] = bcd
}
func predFunc4LD(z *Decoder, y, x int) {
a := int32(z.ybr[y-1][x+0])
b := int32(z.ybr[y-1][x+1])
c := int32(z.ybr[y-1][x+2])
d := int32(z.ybr[y-1][x+3])
e := int32(z.ybr[y-1][x+4])
f := int32(z.ybr[y-1][x+5])
g := int32(z.ybr[y-1][x+6])
h := int32(z.ybr[y-1][x+7])
abc := uint8((a + 2*b + c + 2) / 4)
bcd := uint8((b + 2*c + d + 2) / 4)
cde := uint8((c + 2*d + e + 2) / 4)
def := uint8((d + 2*e + f + 2) / 4)
efg := uint8((e + 2*f + g + 2) / 4)
fgh := uint8((f + 2*g + h + 2) / 4)
ghh := uint8((g + 2*h + h + 2) / 4)
z.ybr[y+0][x+0] = abc
z.ybr[y+0][x+1] = bcd
z.ybr[y+0][x+2] = cde
z.ybr[y+0][x+3] = def
z.ybr[y+1][x+0] = bcd
z.ybr[y+1][x+1] = cde
z.ybr[y+1][x+2] = def
z.ybr[y+1][x+3] = efg
z.ybr[y+2][x+0] = cde
z.ybr[y+2][x+1] = def
z.ybr[y+2][x+2] = efg
z.ybr[y+2][x+3] = fgh
z.ybr[y+3][x+0] = def
z.ybr[y+3][x+1] = efg
z.ybr[y+3][x+2] = fgh
z.ybr[y+3][x+3] = ghh
}
func predFunc4VL(z *Decoder, y, x int) {
a := int32(z.ybr[y-1][x+0])
b := int32(z.ybr[y-1][x+1])
c := int32(z.ybr[y-1][x+2])
d := int32(z.ybr[y-1][x+3])
e := int32(z.ybr[y-1][x+4])
f := int32(z.ybr[y-1][x+5])
g := int32(z.ybr[y-1][x+6])
h := int32(z.ybr[y-1][x+7])
ab := uint8((a + b + 1) / 2)
bc := uint8((b + c + 1) / 2)
cd := uint8((c + d + 1) / 2)
de := uint8((d + e + 1) / 2)
abc := uint8((a + 2*b + c + 2) / 4)
bcd := uint8((b + 2*c + d + 2) / 4)
cde := uint8((c + 2*d + e + 2) / 4)
def := uint8((d + 2*e + f + 2) / 4)
efg := uint8((e + 2*f + g + 2) / 4)
fgh := uint8((f + 2*g + h + 2) / 4)
z.ybr[y+0][x+0] = ab
z.ybr[y+0][x+1] = bc
z.ybr[y+0][x+2] = cd
z.ybr[y+0][x+3] = de
z.ybr[y+1][x+0] = abc
z.ybr[y+1][x+1] = bcd
z.ybr[y+1][x+2] = cde
z.ybr[y+1][x+3] = def
z.ybr[y+2][x+0] = bc
z.ybr[y+2][x+1] = cd
z.ybr[y+2][x+2] = de
z.ybr[y+2][x+3] = efg
z.ybr[y+3][x+0] = bcd
z.ybr[y+3][x+1] = cde
z.ybr[y+3][x+2] = def
z.ybr[y+3][x+3] = fgh
}
func predFunc4HD(z *Decoder, y, x int) {
s := int32(z.ybr[y+3][x-1])
r := int32(z.ybr[y+2][x-1])
q := int32(z.ybr[y+1][x-1])
p := int32(z.ybr[y+0][x-1])
a := int32(z.ybr[y-1][x-1])
b := int32(z.ybr[y-1][x+0])
c := int32(z.ybr[y-1][x+1])
d := int32(z.ybr[y-1][x+2])
sr := uint8((s + r + 1) / 2)
rq := uint8((r + q + 1) / 2)
qp := uint8((q + p + 1) / 2)
pa := uint8((p + a + 1) / 2)
srq := uint8((s + 2*r + q + 2) / 4)
rqp := uint8((r + 2*q + p + 2) / 4)
qpa := uint8((q + 2*p + a + 2) / 4)
pab := uint8((p + 2*a + b + 2) / 4)
abc := uint8((a + 2*b + c + 2) / 4)
bcd := uint8((b + 2*c + d + 2) / 4)
z.ybr[y+0][x+0] = pa
z.ybr[y+0][x+1] = pab
z.ybr[y+0][x+2] = abc
z.ybr[y+0][x+3] = bcd
z.ybr[y+1][x+0] = qp
z.ybr[y+1][x+1] = qpa
z.ybr[y+1][x+2] = pa
z.ybr[y+1][x+3] = pab
z.ybr[y+2][x+0] = rq
z.ybr[y+2][x+1] = rqp
z.ybr[y+2][x+2] = qp
z.ybr[y+2][x+3] = qpa
z.ybr[y+3][x+0] = sr
z.ybr[y+3][x+1] = srq
z.ybr[y+3][x+2] = rq
z.ybr[y+3][x+3] = rqp
}
func predFunc4HU(z *Decoder, y, x int) {
s := int32(z.ybr[y+3][x-1])
r := int32(z.ybr[y+2][x-1])
q := int32(z.ybr[y+1][x-1])
p := int32(z.ybr[y+0][x-1])
pq := uint8((p + q + 1) / 2)
qr := uint8((q + r + 1) / 2)
rs := uint8((r + s + 1) / 2)
pqr := uint8((p + 2*q + r + 2) / 4)
qrs := uint8((q + 2*r + s + 2) / 4)
rss := uint8((r + 2*s + s + 2) / 4)
sss := uint8(s)
z.ybr[y+0][x+0] = pq
z.ybr[y+0][x+1] = pqr
z.ybr[y+0][x+2] = qr
z.ybr[y+0][x+3] = qrs
z.ybr[y+1][x+0] = qr
z.ybr[y+1][x+1] = qrs
z.ybr[y+1][x+2] = rs
z.ybr[y+1][x+3] = rss
z.ybr[y+2][x+0] = rs
z.ybr[y+2][x+1] = rss
z.ybr[y+2][x+2] = sss
z.ybr[y+2][x+3] = sss
z.ybr[y+3][x+0] = sss
z.ybr[y+3][x+1] = sss
z.ybr[y+3][x+2] = sss
z.ybr[y+3][x+3] = sss
}
func predFunc8DC(z *Decoder, y, x int) {
sum := uint32(8)
for i := 0; i < 8; i++ {
sum += uint32(z.ybr[y-1][x+i])
}
for j := 0; j < 8; j++ {
sum += uint32(z.ybr[y+j][x-1])
}
avg := uint8(sum / 16)
for j := 0; j < 8; j++ {
for i := 0; i < 8; i++ {
z.ybr[y+j][x+i] = avg
}
}
}
func predFunc8TM(z *Decoder, y, x int) {
delta0 := -int32(z.ybr[y-1][x-1])
for j := 0; j < 8; j++ {
delta1 := delta0 + int32(z.ybr[y+j][x-1])
for i := 0; i < 8; i++ {
delta2 := delta1 + int32(z.ybr[y-1][x+i])
z.ybr[y+j][x+i] = uint8(clip(delta2, 0, 255))
}
}
}
func predFunc8VE(z *Decoder, y, x int) {
for j := 0; j < 8; j++ {
for i := 0; i < 8; i++ {
z.ybr[y+j][x+i] = z.ybr[y-1][x+i]
}
}
}
func predFunc8HE(z *Decoder, y, x int) {
for j := 0; j < 8; j++ {
for i := 0; i < 8; i++ {
z.ybr[y+j][x+i] = z.ybr[y+j][x-1]
}
}
}
func predFunc8DCTop(z *Decoder, y, x int) {
sum := uint32(4)
for j := 0; j < 8; j++ {
sum += uint32(z.ybr[y+j][x-1])
}
avg := uint8(sum / 8)
for j := 0; j < 8; j++ {
for i := 0; i < 8; i++ {
z.ybr[y+j][x+i] = avg
}
}
}
func predFunc8DCLeft(z *Decoder, y, x int) {
sum := uint32(4)
for i := 0; i < 8; i++ {
sum += uint32(z.ybr[y-1][x+i])
}
avg := uint8(sum / 8)
for j := 0; j < 8; j++ {
for i := 0; i < 8; i++ {
z.ybr[y+j][x+i] = avg
}
}
}
func predFunc8DCTopLeft(z *Decoder, y, x int) {
for j := 0; j < 8; j++ {
for i := 0; i < 8; i++ {
z.ybr[y+j][x+i] = 0x80
}
}
}
func predFunc16DC(z *Decoder, y, x int) {
sum := uint32(16)
for i := 0; i < 16; i++ {
sum += uint32(z.ybr[y-1][x+i])
}
for j := 0; j < 16; j++ {
sum += uint32(z.ybr[y+j][x-1])
}
avg := uint8(sum / 32)
for j := 0; j < 16; j++ {
for i := 0; i < 16; i++ {
z.ybr[y+j][x+i] = avg
}
}
}
func predFunc16TM(z *Decoder, y, x int) {
delta0 := -int32(z.ybr[y-1][x-1])
for j := 0; j < 16; j++ {
delta1 := delta0 + int32(z.ybr[y+j][x-1])
for i := 0; i < 16; i++ {
delta2 := delta1 + int32(z.ybr[y-1][x+i])
z.ybr[y+j][x+i] = uint8(clip(delta2, 0, 255))
}
}
}
func predFunc16VE(z *Decoder, y, x int) {
for j := 0; j < 16; j++ {
for i := 0; i < 16; i++ {
z.ybr[y+j][x+i] = z.ybr[y-1][x+i]
}
}
}
func predFunc16HE(z *Decoder, y, x int) {
for j := 0; j < 16; j++ {
for i := 0; i < 16; i++ {
z.ybr[y+j][x+i] = z.ybr[y+j][x-1]
}
}
}
func predFunc16DCTop(z *Decoder, y, x int) {
sum := uint32(8)
for j := 0; j < 16; j++ {
sum += uint32(z.ybr[y+j][x-1])
}
avg := uint8(sum / 16)
for j := 0; j < 16; j++ {
for i := 0; i < 16; i++ {
z.ybr[y+j][x+i] = avg
}
}
}
func predFunc16DCLeft(z *Decoder, y, x int) {
sum := uint32(8)
for i := 0; i < 16; i++ {
sum += uint32(z.ybr[y-1][x+i])
}
avg := uint8(sum / 16)
for j := 0; j < 16; j++ {
for i := 0; i < 16; i++ {
z.ybr[y+j][x+i] = avg
}
}
}
func predFunc16DCTopLeft(z *Decoder, y, x int) {
for j := 0; j < 16; j++ {
for i := 0; i < 16; i++ {
z.ybr[y+j][x+i] = 0x80
}
}
}

View File

@ -1,98 +0,0 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vp8
// This file implements parsing the quantization factors.
// quant are DC/AC quantization factors.
type quant struct {
y1 [2]uint16
y2 [2]uint16
uv [2]uint16
}
// clip clips x to the range [min, max] inclusive.
func clip(x, min, max int32) int32 {
if x < min {
return min
}
if x > max {
return max
}
return x
}
// parseQuant parses the quantization factors, as specified in section 9.6.
func (d *Decoder) parseQuant() {
baseQ0 := d.fp.readUint(uniformProb, 7)
dqy1DC := d.fp.readOptionalInt(uniformProb, 4)
const dqy1AC = 0
dqy2DC := d.fp.readOptionalInt(uniformProb, 4)
dqy2AC := d.fp.readOptionalInt(uniformProb, 4)
dquvDC := d.fp.readOptionalInt(uniformProb, 4)
dquvAC := d.fp.readOptionalInt(uniformProb, 4)
for i := 0; i < nSegment; i++ {
q := int32(baseQ0)
if d.segmentHeader.useSegment {
if d.segmentHeader.relativeDelta {
q += int32(d.segmentHeader.quantizer[i])
} else {
q = int32(d.segmentHeader.quantizer[i])
}
}
d.quant[i].y1[0] = dequantTableDC[clip(q+dqy1DC, 0, 127)]
d.quant[i].y1[1] = dequantTableAC[clip(q+dqy1AC, 0, 127)]
d.quant[i].y2[0] = dequantTableDC[clip(q+dqy2DC, 0, 127)] * 2
d.quant[i].y2[1] = dequantTableAC[clip(q+dqy2AC, 0, 127)] * 155 / 100
if d.quant[i].y2[1] < 8 {
d.quant[i].y2[1] = 8
}
// The 117 is not a typo. The dequant_init function in the spec's Reference
// Decoder Source Code (http://tools.ietf.org/html/rfc6386#section-9.6 Page 145)
// says to clamp the LHS value at 132, which is equal to dequantTableDC[117].
d.quant[i].uv[0] = dequantTableDC[clip(q+dquvDC, 0, 117)]
d.quant[i].uv[1] = dequantTableAC[clip(q+dquvAC, 0, 127)]
}
}
// The dequantization tables are specified in section 14.1.
var (
dequantTableDC = [128]uint16{
4, 5, 6, 7, 8, 9, 10, 10,
11, 12, 13, 14, 15, 16, 17, 17,
18, 19, 20, 20, 21, 21, 22, 22,
23, 23, 24, 25, 25, 26, 27, 28,
29, 30, 31, 32, 33, 34, 35, 36,
37, 37, 38, 39, 40, 41, 42, 43,
44, 45, 46, 46, 47, 48, 49, 50,
51, 52, 53, 54, 55, 56, 57, 58,
59, 60, 61, 62, 63, 64, 65, 66,
67, 68, 69, 70, 71, 72, 73, 74,
75, 76, 76, 77, 78, 79, 80, 81,
82, 83, 84, 85, 86, 87, 88, 89,
91, 93, 95, 96, 98, 100, 101, 102,
104, 106, 108, 110, 112, 114, 116, 118,
122, 124, 126, 128, 130, 132, 134, 136,
138, 140, 143, 145, 148, 151, 154, 157,
}
dequantTableAC = [128]uint16{
4, 5, 6, 7, 8, 9, 10, 11,
12, 13, 14, 15, 16, 17, 18, 19,
20, 21, 22, 23, 24, 25, 26, 27,
28, 29, 30, 31, 32, 33, 34, 35,
36, 37, 38, 39, 40, 41, 42, 43,
44, 45, 46, 47, 48, 49, 50, 51,
52, 53, 54, 55, 56, 57, 58, 60,
62, 64, 66, 68, 70, 72, 74, 76,
78, 80, 82, 84, 86, 88, 90, 92,
94, 96, 98, 100, 102, 104, 106, 108,
110, 112, 114, 116, 119, 122, 125, 128,
131, 134, 137, 140, 143, 146, 149, 152,
155, 158, 161, 164, 167, 170, 173, 177,
181, 185, 189, 193, 197, 201, 205, 209,
213, 217, 221, 225, 229, 234, 239, 245,
249, 254, 259, 264, 269, 274, 279, 284,
}
)

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@ -1,442 +0,0 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vp8
// This file implements decoding DCT/WHT residual coefficients and
// reconstructing YCbCr data equal to predicted values plus residuals.
//
// There are 1*16*16 + 2*8*8 + 1*4*4 coefficients per macroblock:
// - 1*16*16 luma DCT coefficients,
// - 2*8*8 chroma DCT coefficients, and
// - 1*4*4 luma WHT coefficients.
// Coefficients are read in lots of 16, and the later coefficients in each lot
// are often zero.
//
// The YCbCr data consists of 1*16*16 luma values and 2*8*8 chroma values,
// plus previously decoded values along the top and left borders. The combined
// values are laid out as a [1+16+1+8][32]uint8 so that vertically adjacent
// samples are 32 bytes apart. In detail, the layout is:
//
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
// . . . . . . . a b b b b b b b b b b b b b b b b c c c c . . . . 0
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 1
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 2
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 3
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y c c c c . . . . 4
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 5
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 6
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 7
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y c c c c . . . . 8
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 9
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 10
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 11
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y c c c c . . . . 12
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 13
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 14
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 15
// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 16
// . . . . . . . e f f f f f f f f . . . . . . . g h h h h h h h h 17
// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 18
// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 19
// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 20
// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 21
// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 22
// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 23
// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 24
// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 25
//
// Y, B and R are the reconstructed luma (Y) and chroma (B, R) values.
// The Y values are predicted (either as one 16x16 region or 16 4x4 regions)
// based on the row above's Y values (some combination of {abc} or {dYC}) and
// the column left's Y values (either {ad} or {bY}). Similarly, B and R values
// are predicted on the row above and column left of their respective 8x8
// region: {efi} for B, {ghj} for R.
//
// For uppermost macroblocks (i.e. those with mby == 0), the {abcefgh} values
// are initialized to 0x81. Otherwise, they are copied from the bottom row of
// the macroblock above. The {c} values are then duplicated from row 0 to rows
// 4, 8 and 12 of the ybr workspace.
// Similarly, for leftmost macroblocks (i.e. those with mbx == 0), the {adeigj}
// values are initialized to 0x7f. Otherwise, they are copied from the right
// column of the macroblock to the left.
// For the top-left macroblock (with mby == 0 && mbx == 0), {aeg} is 0x81.
//
// When moving from one macroblock to the next horizontally, the {adeigj}
// values can simply be copied from the workspace to itself, shifted by 8 or
// 16 columns. When moving from one macroblock to the next vertically,
// filtering can occur and hence the row values have to be copied from the
// post-filtered image instead of the pre-filtered workspace.
const (
bCoeffBase = 1*16*16 + 0*8*8
rCoeffBase = 1*16*16 + 1*8*8
whtCoeffBase = 1*16*16 + 2*8*8
)
const (
ybrYX = 8
ybrYY = 1
ybrBX = 8
ybrBY = 18
ybrRX = 24
ybrRY = 18
)
// prepareYBR prepares the {abcdefghij} elements of ybr.
func (d *Decoder) prepareYBR(mbx, mby int) {
if mbx == 0 {
for y := 0; y < 17; y++ {
d.ybr[y][7] = 0x81
}
for y := 17; y < 26; y++ {
d.ybr[y][7] = 0x81
d.ybr[y][23] = 0x81
}
} else {
for y := 0; y < 17; y++ {
d.ybr[y][7] = d.ybr[y][7+16]
}
for y := 17; y < 26; y++ {
d.ybr[y][7] = d.ybr[y][15]
d.ybr[y][23] = d.ybr[y][31]
}
}
if mby == 0 {
for x := 7; x < 28; x++ {
d.ybr[0][x] = 0x7f
}
for x := 7; x < 16; x++ {
d.ybr[17][x] = 0x7f
}
for x := 23; x < 32; x++ {
d.ybr[17][x] = 0x7f
}
} else {
for i := 0; i < 16; i++ {
d.ybr[0][8+i] = d.img.Y[(16*mby-1)*d.img.YStride+16*mbx+i]
}
for i := 0; i < 8; i++ {
d.ybr[17][8+i] = d.img.Cb[(8*mby-1)*d.img.CStride+8*mbx+i]
}
for i := 0; i < 8; i++ {
d.ybr[17][24+i] = d.img.Cr[(8*mby-1)*d.img.CStride+8*mbx+i]
}
if mbx == d.mbw-1 {
for i := 16; i < 20; i++ {
d.ybr[0][8+i] = d.img.Y[(16*mby-1)*d.img.YStride+16*mbx+15]
}
} else {
for i := 16; i < 20; i++ {
d.ybr[0][8+i] = d.img.Y[(16*mby-1)*d.img.YStride+16*mbx+i]
}
}
}
for y := 4; y < 16; y += 4 {
d.ybr[y][24] = d.ybr[0][24]
d.ybr[y][25] = d.ybr[0][25]
d.ybr[y][26] = d.ybr[0][26]
d.ybr[y][27] = d.ybr[0][27]
}
}
// btou converts a bool to a 0/1 value.
func btou(b bool) uint8 {
if b {
return 1
}
return 0
}
// pack packs four 0/1 values into four bits of a uint32.
func pack(x [4]uint8, shift int) uint32 {
u := uint32(x[0])<<0 | uint32(x[1])<<1 | uint32(x[2])<<2 | uint32(x[3])<<3
return u << uint(shift)
}
// unpack unpacks four 0/1 values from a four-bit value.
var unpack = [16][4]uint8{
{0, 0, 0, 0},
{1, 0, 0, 0},
{0, 1, 0, 0},
{1, 1, 0, 0},
{0, 0, 1, 0},
{1, 0, 1, 0},
{0, 1, 1, 0},
{1, 1, 1, 0},
{0, 0, 0, 1},
{1, 0, 0, 1},
{0, 1, 0, 1},
{1, 1, 0, 1},
{0, 0, 1, 1},
{1, 0, 1, 1},
{0, 1, 1, 1},
{1, 1, 1, 1},
}
var (
// The mapping from 4x4 region position to band is specified in section 13.3.
bands = [17]uint8{0, 1, 2, 3, 6, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 0}
// Category probabilties are specified in section 13.2.
// Decoding categories 1 and 2 are done inline.
cat3456 = [4][12]uint8{
{173, 148, 140, 0, 0, 0, 0, 0, 0, 0, 0, 0},
{176, 155, 140, 135, 0, 0, 0, 0, 0, 0, 0, 0},
{180, 157, 141, 134, 130, 0, 0, 0, 0, 0, 0, 0},
{254, 254, 243, 230, 196, 177, 153, 140, 133, 130, 129, 0},
}
// The zigzag order is:
// 0 1 5 6
// 2 4 7 12
// 3 8 11 13
// 9 10 14 15
zigzag = [16]uint8{0, 1, 4, 8, 5, 2, 3, 6, 9, 12, 13, 10, 7, 11, 14, 15}
)
// parseResiduals4 parses a 4x4 region of residual coefficients, as specified
// in section 13.3, and returns a 0/1 value indicating whether there was at
// least one non-zero coefficient.
// r is the partition to read bits from.
// plane and context describe which token probability table to use. context is
// either 0, 1 or 2, and equals how many of the macroblock left and macroblock
// above have non-zero coefficients.
// quant are the DC/AC quantization factors.
// skipFirstCoeff is whether the DC coefficient has already been parsed.
// coeffBase is the base index of d.coeff to write to.
func (d *Decoder) parseResiduals4(r *partition, plane int, context uint8, quant [2]uint16, skipFirstCoeff bool, coeffBase int) uint8 {
prob, n := &d.tokenProb[plane], 0
if skipFirstCoeff {
n = 1
}
p := prob[bands[n]][context]
if !r.readBit(p[0]) {
return 0
}
for n != 16 {
n++
if !r.readBit(p[1]) {
p = prob[bands[n]][0]
continue
}
var v uint32
if !r.readBit(p[2]) {
v = 1
p = prob[bands[n]][1]
} else {
if !r.readBit(p[3]) {
if !r.readBit(p[4]) {
v = 2
} else {
v = 3 + r.readUint(p[5], 1)
}
} else if !r.readBit(p[6]) {
if !r.readBit(p[7]) {
// Category 1.
v = 5 + r.readUint(159, 1)
} else {
// Category 2.
v = 7 + 2*r.readUint(165, 1) + r.readUint(145, 1)
}
} else {
// Categories 3, 4, 5 or 6.
b1 := r.readUint(p[8], 1)
b0 := r.readUint(p[9+b1], 1)
cat := 2*b1 + b0
tab := &cat3456[cat]
v = 0
for i := 0; tab[i] != 0; i++ {
v *= 2
v += r.readUint(tab[i], 1)
}
v += 3 + (8 << cat)
}
p = prob[bands[n]][2]
}
z := zigzag[n-1]
c := int32(v) * int32(quant[btou(z > 0)])
if r.readBit(uniformProb) {
c = -c
}
d.coeff[coeffBase+int(z)] = int16(c)
if n == 16 || !r.readBit(p[0]) {
return 1
}
}
return 1
}
// parseResiduals parses the residuals and returns whether inner loop filtering
// should be skipped for this macroblock.
func (d *Decoder) parseResiduals(mbx, mby int) (skip bool) {
partition := &d.op[mby&(d.nOP-1)]
plane := planeY1SansY2
quant := &d.quant[d.segment]
// Parse the DC coefficient of each 4x4 luma region.
if d.usePredY16 {
nz := d.parseResiduals4(partition, planeY2, d.leftMB.nzY16+d.upMB[mbx].nzY16, quant.y2, false, whtCoeffBase)
d.leftMB.nzY16 = nz
d.upMB[mbx].nzY16 = nz
d.inverseWHT16()
plane = planeY1WithY2
}
var (
nzDC, nzAC [4]uint8
nzDCMask, nzACMask uint32
coeffBase int
)
// Parse the luma coefficients.
lnz := unpack[d.leftMB.nzMask&0x0f]
unz := unpack[d.upMB[mbx].nzMask&0x0f]
for y := 0; y < 4; y++ {
nz := lnz[y]
for x := 0; x < 4; x++ {
nz = d.parseResiduals4(partition, plane, nz+unz[x], quant.y1, d.usePredY16, coeffBase)
unz[x] = nz
nzAC[x] = nz
nzDC[x] = btou(d.coeff[coeffBase] != 0)
coeffBase += 16
}
lnz[y] = nz
nzDCMask |= pack(nzDC, y*4)
nzACMask |= pack(nzAC, y*4)
}
lnzMask := pack(lnz, 0)
unzMask := pack(unz, 0)
// Parse the chroma coefficients.
lnz = unpack[d.leftMB.nzMask>>4]
unz = unpack[d.upMB[mbx].nzMask>>4]
for c := 0; c < 4; c += 2 {
for y := 0; y < 2; y++ {
nz := lnz[y+c]
for x := 0; x < 2; x++ {
nz = d.parseResiduals4(partition, planeUV, nz+unz[x+c], quant.uv, false, coeffBase)
unz[x+c] = nz
nzAC[y*2+x] = nz
nzDC[y*2+x] = btou(d.coeff[coeffBase] != 0)
coeffBase += 16
}
lnz[y+c] = nz
}
nzDCMask |= pack(nzDC, 16+c*2)
nzACMask |= pack(nzAC, 16+c*2)
}
lnzMask |= pack(lnz, 4)
unzMask |= pack(unz, 4)
// Save decoder state.
d.leftMB.nzMask = uint8(lnzMask)
d.upMB[mbx].nzMask = uint8(unzMask)
d.nzDCMask = nzDCMask
d.nzACMask = nzACMask
// Section 15.1 of the spec says that "Steps 2 and 4 [of the loop filter]
// are skipped... [if] there is no DCT coefficient coded for the whole
// macroblock."
return nzDCMask == 0 && nzACMask == 0
}
// reconstructMacroblock applies the predictor functions and adds the inverse-
// DCT transformed residuals to recover the YCbCr data.
func (d *Decoder) reconstructMacroblock(mbx, mby int) {
if d.usePredY16 {
p := checkTopLeftPred(mbx, mby, d.predY16)
predFunc16[p](d, 1, 8)
for j := 0; j < 4; j++ {
for i := 0; i < 4; i++ {
n := 4*j + i
y := 4*j + 1
x := 4*i + 8
mask := uint32(1) << uint(n)
if d.nzACMask&mask != 0 {
d.inverseDCT4(y, x, 16*n)
} else if d.nzDCMask&mask != 0 {
d.inverseDCT4DCOnly(y, x, 16*n)
}
}
}
} else {
for j := 0; j < 4; j++ {
for i := 0; i < 4; i++ {
n := 4*j + i
y := 4*j + 1
x := 4*i + 8
predFunc4[d.predY4[j][i]](d, y, x)
mask := uint32(1) << uint(n)
if d.nzACMask&mask != 0 {
d.inverseDCT4(y, x, 16*n)
} else if d.nzDCMask&mask != 0 {
d.inverseDCT4DCOnly(y, x, 16*n)
}
}
}
}
p := checkTopLeftPred(mbx, mby, d.predC8)
predFunc8[p](d, ybrBY, ybrBX)
if d.nzACMask&0x0f0000 != 0 {
d.inverseDCT8(ybrBY, ybrBX, bCoeffBase)
} else if d.nzDCMask&0x0f0000 != 0 {
d.inverseDCT8DCOnly(ybrBY, ybrBX, bCoeffBase)
}
predFunc8[p](d, ybrRY, ybrRX)
if d.nzACMask&0xf00000 != 0 {
d.inverseDCT8(ybrRY, ybrRX, rCoeffBase)
} else if d.nzDCMask&0xf00000 != 0 {
d.inverseDCT8DCOnly(ybrRY, ybrRX, rCoeffBase)
}
}
// reconstruct reconstructs one macroblock and returns whether inner loop
// filtering should be skipped for it.
func (d *Decoder) reconstruct(mbx, mby int) (skip bool) {
if d.segmentHeader.updateMap {
if !d.fp.readBit(d.segmentHeader.prob[0]) {
d.segment = int(d.fp.readUint(d.segmentHeader.prob[1], 1))
} else {
d.segment = int(d.fp.readUint(d.segmentHeader.prob[2], 1)) + 2
}
}
if d.useSkipProb {
skip = d.fp.readBit(d.skipProb)
}
// Prepare the workspace.
for i := range d.coeff {
d.coeff[i] = 0
}
d.prepareYBR(mbx, mby)
// Parse the predictor modes.
d.usePredY16 = d.fp.readBit(145)
if d.usePredY16 {
d.parsePredModeY16(mbx)
} else {
d.parsePredModeY4(mbx)
}
d.parsePredModeC8()
// Parse the residuals.
if !skip {
skip = d.parseResiduals(mbx, mby)
} else {
if d.usePredY16 {
d.leftMB.nzY16 = 0
d.upMB[mbx].nzY16 = 0
}
d.leftMB.nzMask = 0
d.upMB[mbx].nzMask = 0
d.nzDCMask = 0
d.nzACMask = 0
}
// Reconstruct the YCbCr data and copy it to the image.
d.reconstructMacroblock(mbx, mby)
for i, y := (mby*d.img.YStride+mbx)*16, 0; y < 16; i, y = i+d.img.YStride, y+1 {
copy(d.img.Y[i:i+16], d.ybr[ybrYY+y][ybrYX:ybrYX+16])
}
for i, y := (mby*d.img.CStride+mbx)*8, 0; y < 8; i, y = i+d.img.CStride, y+1 {
copy(d.img.Cb[i:i+8], d.ybr[ybrBY+y][ybrBX:ybrBX+8])
copy(d.img.Cr[i:i+8], d.ybr[ybrRY+y][ybrRX:ybrRX+8])
}
return skip
}

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@ -1,381 +0,0 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vp8
// This file contains token probabilities for decoding DCT/WHT coefficients, as
// specified in chapter 13.
func (d *Decoder) parseTokenProb() {
for i := range d.tokenProb {
for j := range d.tokenProb[i] {
for k := range d.tokenProb[i][j] {
for l := range d.tokenProb[i][j][k] {
if d.fp.readBit(tokenProbUpdateProb[i][j][k][l]) {
d.tokenProb[i][j][k][l] = uint8(d.fp.readUint(uniformProb, 8))
}
}
}
}
}
}
// The plane enumeration is specified in section 13.3.
const (
planeY1WithY2 = iota
planeY2
planeUV
planeY1SansY2
nPlane
)
const (
nBand = 8
nContext = 3
nProb = 11
)
// Token probability update probabilities are specified in section 13.4.
var tokenProbUpdateProb = [nPlane][nBand][nContext][nProb]uint8{
{
{
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{176, 246, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{223, 241, 252, 255, 255, 255, 255, 255, 255, 255, 255},
{249, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 244, 252, 255, 255, 255, 255, 255, 255, 255, 255},
{234, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 246, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{239, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{251, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{251, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 254, 253, 255, 254, 255, 255, 255, 255, 255, 255},
{250, 255, 254, 255, 254, 255, 255, 255, 255, 255, 255},
{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
},
{
{
{217, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{225, 252, 241, 253, 255, 255, 254, 255, 255, 255, 255},
{234, 250, 241, 250, 253, 255, 253, 254, 255, 255, 255},
},
{
{255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{223, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{238, 253, 254, 254, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{249, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 253, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{247, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{252, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255},
{250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
},
{
{
{186, 251, 250, 255, 255, 255, 255, 255, 255, 255, 255},
{234, 251, 244, 254, 255, 255, 255, 255, 255, 255, 255},
{251, 251, 243, 253, 254, 255, 254, 255, 255, 255, 255},
},
{
{255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{236, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{251, 253, 253, 254, 254, 255, 255, 255, 255, 255, 255},
},
{
{255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{254, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{254, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
},
{
{
{248, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{250, 254, 252, 254, 255, 255, 255, 255, 255, 255, 255},
{248, 254, 249, 253, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255},
{246, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255},
{252, 254, 251, 254, 254, 255, 255, 255, 255, 255, 255},
},
{
{255, 254, 252, 255, 255, 255, 255, 255, 255, 255, 255},
{248, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255},
{253, 255, 254, 254, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{245, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{253, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 251, 253, 255, 255, 255, 255, 255, 255, 255, 255},
{252, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 252, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{249, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 255, 253, 255, 255, 255, 255, 255, 255, 255, 255},
{250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
{
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255},
},
},
}
// Default token probabilities are specified in section 13.5.
var defaultTokenProb = [nPlane][nBand][nContext][nProb]uint8{
{
{
{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
},
{
{253, 136, 254, 255, 228, 219, 128, 128, 128, 128, 128},
{189, 129, 242, 255, 227, 213, 255, 219, 128, 128, 128},
{106, 126, 227, 252, 214, 209, 255, 255, 128, 128, 128},
},
{
{1, 98, 248, 255, 236, 226, 255, 255, 128, 128, 128},
{181, 133, 238, 254, 221, 234, 255, 154, 128, 128, 128},
{78, 134, 202, 247, 198, 180, 255, 219, 128, 128, 128},
},
{
{1, 185, 249, 255, 243, 255, 128, 128, 128, 128, 128},
{184, 150, 247, 255, 236, 224, 128, 128, 128, 128, 128},
{77, 110, 216, 255, 236, 230, 128, 128, 128, 128, 128},
},
{
{1, 101, 251, 255, 241, 255, 128, 128, 128, 128, 128},
{170, 139, 241, 252, 236, 209, 255, 255, 128, 128, 128},
{37, 116, 196, 243, 228, 255, 255, 255, 128, 128, 128},
},
{
{1, 204, 254, 255, 245, 255, 128, 128, 128, 128, 128},
{207, 160, 250, 255, 238, 128, 128, 128, 128, 128, 128},
{102, 103, 231, 255, 211, 171, 128, 128, 128, 128, 128},
},
{
{1, 152, 252, 255, 240, 255, 128, 128, 128, 128, 128},
{177, 135, 243, 255, 234, 225, 128, 128, 128, 128, 128},
{80, 129, 211, 255, 194, 224, 128, 128, 128, 128, 128},
},
{
{1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
{246, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
{255, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
},
},
{
{
{198, 35, 237, 223, 193, 187, 162, 160, 145, 155, 62},
{131, 45, 198, 221, 172, 176, 220, 157, 252, 221, 1},
{68, 47, 146, 208, 149, 167, 221, 162, 255, 223, 128},
},
{
{1, 149, 241, 255, 221, 224, 255, 255, 128, 128, 128},
{184, 141, 234, 253, 222, 220, 255, 199, 128, 128, 128},
{81, 99, 181, 242, 176, 190, 249, 202, 255, 255, 128},
},
{
{1, 129, 232, 253, 214, 197, 242, 196, 255, 255, 128},
{99, 121, 210, 250, 201, 198, 255, 202, 128, 128, 128},
{23, 91, 163, 242, 170, 187, 247, 210, 255, 255, 128},
},
{
{1, 200, 246, 255, 234, 255, 128, 128, 128, 128, 128},
{109, 178, 241, 255, 231, 245, 255, 255, 128, 128, 128},
{44, 130, 201, 253, 205, 192, 255, 255, 128, 128, 128},
},
{
{1, 132, 239, 251, 219, 209, 255, 165, 128, 128, 128},
{94, 136, 225, 251, 218, 190, 255, 255, 128, 128, 128},
{22, 100, 174, 245, 186, 161, 255, 199, 128, 128, 128},
},
{
{1, 182, 249, 255, 232, 235, 128, 128, 128, 128, 128},
{124, 143, 241, 255, 227, 234, 128, 128, 128, 128, 128},
{35, 77, 181, 251, 193, 211, 255, 205, 128, 128, 128},
},
{
{1, 157, 247, 255, 236, 231, 255, 255, 128, 128, 128},
{121, 141, 235, 255, 225, 227, 255, 255, 128, 128, 128},
{45, 99, 188, 251, 195, 217, 255, 224, 128, 128, 128},
},
{
{1, 1, 251, 255, 213, 255, 128, 128, 128, 128, 128},
{203, 1, 248, 255, 255, 128, 128, 128, 128, 128, 128},
{137, 1, 177, 255, 224, 255, 128, 128, 128, 128, 128},
},
},
{
{
{253, 9, 248, 251, 207, 208, 255, 192, 128, 128, 128},
{175, 13, 224, 243, 193, 185, 249, 198, 255, 255, 128},
{73, 17, 171, 221, 161, 179, 236, 167, 255, 234, 128},
},
{
{1, 95, 247, 253, 212, 183, 255, 255, 128, 128, 128},
{239, 90, 244, 250, 211, 209, 255, 255, 128, 128, 128},
{155, 77, 195, 248, 188, 195, 255, 255, 128, 128, 128},
},
{
{1, 24, 239, 251, 218, 219, 255, 205, 128, 128, 128},
{201, 51, 219, 255, 196, 186, 128, 128, 128, 128, 128},
{69, 46, 190, 239, 201, 218, 255, 228, 128, 128, 128},
},
{
{1, 191, 251, 255, 255, 128, 128, 128, 128, 128, 128},
{223, 165, 249, 255, 213, 255, 128, 128, 128, 128, 128},
{141, 124, 248, 255, 255, 128, 128, 128, 128, 128, 128},
},
{
{1, 16, 248, 255, 255, 128, 128, 128, 128, 128, 128},
{190, 36, 230, 255, 236, 255, 128, 128, 128, 128, 128},
{149, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
},
{
{1, 226, 255, 128, 128, 128, 128, 128, 128, 128, 128},
{247, 192, 255, 128, 128, 128, 128, 128, 128, 128, 128},
{240, 128, 255, 128, 128, 128, 128, 128, 128, 128, 128},
},
{
{1, 134, 252, 255, 255, 128, 128, 128, 128, 128, 128},
{213, 62, 250, 255, 255, 128, 128, 128, 128, 128, 128},
{55, 93, 255, 128, 128, 128, 128, 128, 128, 128, 128},
},
{
{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128},
},
},
{
{
{202, 24, 213, 235, 186, 191, 220, 160, 240, 175, 255},
{126, 38, 182, 232, 169, 184, 228, 174, 255, 187, 128},
{61, 46, 138, 219, 151, 178, 240, 170, 255, 216, 128},
},
{
{1, 112, 230, 250, 199, 191, 247, 159, 255, 255, 128},
{166, 109, 228, 252, 211, 215, 255, 174, 128, 128, 128},
{39, 77, 162, 232, 172, 180, 245, 178, 255, 255, 128},
},
{
{1, 52, 220, 246, 198, 199, 249, 220, 255, 255, 128},
{124, 74, 191, 243, 183, 193, 250, 221, 255, 255, 128},
{24, 71, 130, 219, 154, 170, 243, 182, 255, 255, 128},
},
{
{1, 182, 225, 249, 219, 240, 255, 224, 128, 128, 128},
{149, 150, 226, 252, 216, 205, 255, 171, 128, 128, 128},
{28, 108, 170, 242, 183, 194, 254, 223, 255, 255, 128},
},
{
{1, 81, 230, 252, 204, 203, 255, 192, 128, 128, 128},
{123, 102, 209, 247, 188, 196, 255, 233, 128, 128, 128},
{20, 95, 153, 243, 164, 173, 255, 203, 128, 128, 128},
},
{
{1, 222, 248, 255, 216, 213, 128, 128, 128, 128, 128},
{168, 175, 246, 252, 235, 205, 255, 255, 128, 128, 128},
{47, 116, 215, 255, 211, 212, 255, 255, 128, 128, 128},
},
{
{1, 121, 236, 253, 212, 214, 255, 255, 128, 128, 128},
{141, 84, 213, 252, 201, 202, 255, 219, 128, 128, 128},
{42, 80, 160, 240, 162, 185, 255, 205, 128, 128, 128},
},
{
{1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
{244, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
{238, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128},
},
},
}

View File

@ -1,603 +0,0 @@
// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package vp8l implements a decoder for the VP8L lossless image format.
//
// The VP8L specification is at:
// https://developers.google.com/speed/webp/docs/riff_container
package vp8l // import "golang.org/x/image/vp8l"
import (
"bufio"
"errors"
"image"
"image/color"
"io"
)
var (
errInvalidCodeLengths = errors.New("vp8l: invalid code lengths")
errInvalidHuffmanTree = errors.New("vp8l: invalid Huffman tree")
)
// colorCacheMultiplier is the multiplier used for the color cache hash
// function, specified in section 4.2.3.
const colorCacheMultiplier = 0x1e35a7bd
// distanceMapTable is the look-up table for distanceMap.
var distanceMapTable = [120]uint8{
0x18, 0x07, 0x17, 0x19, 0x28, 0x06, 0x27, 0x29, 0x16, 0x1a,
0x26, 0x2a, 0x38, 0x05, 0x37, 0x39, 0x15, 0x1b, 0x36, 0x3a,
0x25, 0x2b, 0x48, 0x04, 0x47, 0x49, 0x14, 0x1c, 0x35, 0x3b,
0x46, 0x4a, 0x24, 0x2c, 0x58, 0x45, 0x4b, 0x34, 0x3c, 0x03,
0x57, 0x59, 0x13, 0x1d, 0x56, 0x5a, 0x23, 0x2d, 0x44, 0x4c,
0x55, 0x5b, 0x33, 0x3d, 0x68, 0x02, 0x67, 0x69, 0x12, 0x1e,
0x66, 0x6a, 0x22, 0x2e, 0x54, 0x5c, 0x43, 0x4d, 0x65, 0x6b,
0x32, 0x3e, 0x78, 0x01, 0x77, 0x79, 0x53, 0x5d, 0x11, 0x1f,
0x64, 0x6c, 0x42, 0x4e, 0x76, 0x7a, 0x21, 0x2f, 0x75, 0x7b,
0x31, 0x3f, 0x63, 0x6d, 0x52, 0x5e, 0x00, 0x74, 0x7c, 0x41,
0x4f, 0x10, 0x20, 0x62, 0x6e, 0x30, 0x73, 0x7d, 0x51, 0x5f,
0x40, 0x72, 0x7e, 0x61, 0x6f, 0x50, 0x71, 0x7f, 0x60, 0x70,
}
// distanceMap maps a LZ77 backwards reference distance to a two-dimensional
// pixel offset, specified in section 4.2.2.
func distanceMap(w int32, code uint32) int32 {
if int32(code) > int32(len(distanceMapTable)) {
return int32(code) - int32(len(distanceMapTable))
}
distCode := int32(distanceMapTable[code-1])
yOffset := distCode >> 4
xOffset := 8 - distCode&0xf
if d := yOffset*w + xOffset; d >= 1 {
return d
}
return 1
}
// decoder holds the bit-stream for a VP8L image.
type decoder struct {
r io.ByteReader
bits uint32
nBits uint32
}
// read reads the next n bits from the decoder's bit-stream.
func (d *decoder) read(n uint32) (uint32, error) {
for d.nBits < n {
c, err := d.r.ReadByte()
if err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return 0, err
}
d.bits |= uint32(c) << d.nBits
d.nBits += 8
}
u := d.bits & (1<<n - 1)
d.bits >>= n
d.nBits -= n
return u, nil
}
// decodeTransform decodes the next transform and the width of the image after
// transformation (or equivalently, before inverse transformation), specified
// in section 3.
func (d *decoder) decodeTransform(w int32, h int32) (t transform, newWidth int32, err error) {
t.oldWidth = w
t.transformType, err = d.read(2)
if err != nil {
return transform{}, 0, err
}
switch t.transformType {
case transformTypePredictor, transformTypeCrossColor:
t.bits, err = d.read(3)
if err != nil {
return transform{}, 0, err
}
t.bits += 2
t.pix, err = d.decodePix(nTiles(w, t.bits), nTiles(h, t.bits), 0, false)
if err != nil {
return transform{}, 0, err
}
case transformTypeSubtractGreen:
// No-op.
case transformTypeColorIndexing:
nColors, err := d.read(8)
if err != nil {
return transform{}, 0, err
}
nColors++
t.bits = 0
switch {
case nColors <= 2:
t.bits = 3
case nColors <= 4:
t.bits = 2
case nColors <= 16:
t.bits = 1
}
w = nTiles(w, t.bits)
pix, err := d.decodePix(int32(nColors), 1, 4*256, false)
if err != nil {
return transform{}, 0, err
}
for p := 4; p < len(pix); p += 4 {
pix[p+0] += pix[p-4]
pix[p+1] += pix[p-3]
pix[p+2] += pix[p-2]
pix[p+3] += pix[p-1]
}
// The spec says that "if the index is equal or larger than color_table_size,
// the argb color value should be set to 0x00000000 (transparent black)."
// We re-slice up to 256 4-byte pixels.
t.pix = pix[:4*256]
}
return t, w, nil
}
// repeatsCodeLength is the minimum code length for repeated codes.
const repeatsCodeLength = 16
// These magic numbers are specified at the end of section 5.2.2.
// The 3-length arrays apply to code lengths >= repeatsCodeLength.
var (
codeLengthCodeOrder = [19]uint8{
17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
}
repeatBits = [3]uint8{2, 3, 7}
repeatOffsets = [3]uint8{3, 3, 11}
)
// decodeCodeLengths decodes a Huffman tree's code lengths which are themselves
// encoded via a Huffman tree, specified in section 5.2.2.
func (d *decoder) decodeCodeLengths(dst []uint32, codeLengthCodeLengths []uint32) error {
h := hTree{}
if err := h.build(codeLengthCodeLengths); err != nil {
return err
}
maxSymbol := len(dst)
useLength, err := d.read(1)
if err != nil {
return err
}
if useLength != 0 {
n, err := d.read(3)
if err != nil {
return err
}
n = 2 + 2*n
ms, err := d.read(n)
if err != nil {
return err
}
maxSymbol = int(ms) + 2
if maxSymbol > len(dst) {
return errInvalidCodeLengths
}
}
// The spec says that "if code 16 [meaning repeat] is used before
// a non-zero value has been emitted, a value of 8 is repeated."
prevCodeLength := uint32(8)
for symbol := 0; symbol < len(dst); {
if maxSymbol == 0 {
break
}
maxSymbol--
codeLength, err := h.next(d)
if err != nil {
return err
}
if codeLength < repeatsCodeLength {
dst[symbol] = codeLength
symbol++
if codeLength != 0 {
prevCodeLength = codeLength
}
continue
}
repeat, err := d.read(uint32(repeatBits[codeLength-repeatsCodeLength]))
if err != nil {
return err
}
repeat += uint32(repeatOffsets[codeLength-repeatsCodeLength])
if symbol+int(repeat) > len(dst) {
return errInvalidCodeLengths
}
// A code length of 16 repeats the previous non-zero code.
// A code length of 17 or 18 repeats zeroes.
cl := uint32(0)
if codeLength == 16 {
cl = prevCodeLength
}
for ; repeat > 0; repeat-- {
dst[symbol] = cl
symbol++
}
}
return nil
}
// decodeHuffmanTree decodes a Huffman tree into h.
func (d *decoder) decodeHuffmanTree(h *hTree, alphabetSize uint32) error {
useSimple, err := d.read(1)
if err != nil {
return err
}
if useSimple != 0 {
nSymbols, err := d.read(1)
if err != nil {
return err
}
nSymbols++
firstSymbolLengthCode, err := d.read(1)
if err != nil {
return err
}
firstSymbolLengthCode = 7*firstSymbolLengthCode + 1
var symbols [2]uint32
symbols[0], err = d.read(firstSymbolLengthCode)
if err != nil {
return err
}
if nSymbols == 2 {
symbols[1], err = d.read(8)
if err != nil {
return err
}
}
return h.buildSimple(nSymbols, symbols, alphabetSize)
}
nCodes, err := d.read(4)
if err != nil {
return err
}
nCodes += 4
if int(nCodes) > len(codeLengthCodeOrder) {
return errInvalidHuffmanTree
}
codeLengthCodeLengths := [len(codeLengthCodeOrder)]uint32{}
for i := uint32(0); i < nCodes; i++ {
codeLengthCodeLengths[codeLengthCodeOrder[i]], err = d.read(3)
if err != nil {
return err
}
}
codeLengths := make([]uint32, alphabetSize)
if err = d.decodeCodeLengths(codeLengths, codeLengthCodeLengths[:]); err != nil {
return err
}
return h.build(codeLengths)
}
const (
huffGreen = 0
huffRed = 1
huffBlue = 2
huffAlpha = 3
huffDistance = 4
nHuff = 5
)
// hGroup is an array of 5 Huffman trees.
type hGroup [nHuff]hTree
// decodeHuffmanGroups decodes the one or more hGroups used to decode the pixel
// data. If one hGroup is used for the entire image, then hPix and hBits will
// be zero. If more than one hGroup is used, then hPix contains the meta-image
// that maps tiles to hGroup index, and hBits contains the log-2 tile size.
func (d *decoder) decodeHuffmanGroups(w int32, h int32, topLevel bool, ccBits uint32) (
hGroups []hGroup, hPix []byte, hBits uint32, err error) {
maxHGroupIndex := 0
if topLevel {
useMeta, err := d.read(1)
if err != nil {
return nil, nil, 0, err
}
if useMeta != 0 {
hBits, err = d.read(3)
if err != nil {
return nil, nil, 0, err
}
hBits += 2
hPix, err = d.decodePix(nTiles(w, hBits), nTiles(h, hBits), 0, false)
if err != nil {
return nil, nil, 0, err
}
for p := 0; p < len(hPix); p += 4 {
i := int(hPix[p])<<8 | int(hPix[p+1])
if maxHGroupIndex < i {
maxHGroupIndex = i
}
}
}
}
hGroups = make([]hGroup, maxHGroupIndex+1)
for i := range hGroups {
for j, alphabetSize := range alphabetSizes {
if j == 0 && ccBits > 0 {
alphabetSize += 1 << ccBits
}
if err := d.decodeHuffmanTree(&hGroups[i][j], alphabetSize); err != nil {
return nil, nil, 0, err
}
}
}
return hGroups, hPix, hBits, nil
}
const (
nLiteralCodes = 256
nLengthCodes = 24
nDistanceCodes = 40
)
var alphabetSizes = [nHuff]uint32{
nLiteralCodes + nLengthCodes,
nLiteralCodes,
nLiteralCodes,
nLiteralCodes,
nDistanceCodes,
}
// decodePix decodes pixel data, specified in section 5.2.2.
func (d *decoder) decodePix(w int32, h int32, minCap int32, topLevel bool) ([]byte, error) {
// Decode the color cache parameters.
ccBits, ccShift, ccEntries := uint32(0), uint32(0), ([]uint32)(nil)
useColorCache, err := d.read(1)
if err != nil {
return nil, err
}
if useColorCache != 0 {
ccBits, err = d.read(4)
if err != nil {
return nil, err
}
if ccBits < 1 || 11 < ccBits {
return nil, errors.New("vp8l: invalid color cache parameters")
}
ccShift = 32 - ccBits
ccEntries = make([]uint32, 1<<ccBits)
}
// Decode the Huffman groups.
hGroups, hPix, hBits, err := d.decodeHuffmanGroups(w, h, topLevel, ccBits)
if err != nil {
return nil, err
}
hMask, tilesPerRow := int32(0), int32(0)
if hBits != 0 {
hMask, tilesPerRow = 1<<hBits-1, nTiles(w, hBits)
}
// Decode the pixels.
if minCap < 4*w*h {
minCap = 4 * w * h
}
pix := make([]byte, 4*w*h, minCap)
p, cachedP := 0, 0
x, y := int32(0), int32(0)
hg, lookupHG := &hGroups[0], hMask != 0
for p < len(pix) {
if lookupHG {
i := 4 * (tilesPerRow*(y>>hBits) + (x >> hBits))
hg = &hGroups[uint32(hPix[i])<<8|uint32(hPix[i+1])]
}
green, err := hg[huffGreen].next(d)
if err != nil {
return nil, err
}
switch {
case green < nLiteralCodes:
// We have a literal pixel.
red, err := hg[huffRed].next(d)
if err != nil {
return nil, err
}
blue, err := hg[huffBlue].next(d)
if err != nil {
return nil, err
}
alpha, err := hg[huffAlpha].next(d)
if err != nil {
return nil, err
}
pix[p+0] = uint8(red)
pix[p+1] = uint8(green)
pix[p+2] = uint8(blue)
pix[p+3] = uint8(alpha)
p += 4
x++
if x == w {
x, y = 0, y+1
}
lookupHG = hMask != 0 && x&hMask == 0
case green < nLiteralCodes+nLengthCodes:
// We have a LZ77 backwards reference.
length, err := d.lz77Param(green - nLiteralCodes)
if err != nil {
return nil, err
}
distSym, err := hg[huffDistance].next(d)
if err != nil {
return nil, err
}
distCode, err := d.lz77Param(distSym)
if err != nil {
return nil, err
}
dist := distanceMap(w, distCode)
pEnd := p + 4*int(length)
q := p - 4*int(dist)
qEnd := pEnd - 4*int(dist)
if p < 0 || len(pix) < pEnd || q < 0 || len(pix) < qEnd {
return nil, errors.New("vp8l: invalid LZ77 parameters")
}
for ; p < pEnd; p, q = p+1, q+1 {
pix[p] = pix[q]
}
x += int32(length)
for x >= w {
x, y = x-w, y+1
}
lookupHG = hMask != 0
default:
// We have a color cache lookup. First, insert previous pixels
// into the cache. Note that VP8L assumes ARGB order, but the
// Go image.RGBA type is in RGBA order.
for ; cachedP < p; cachedP += 4 {
argb := uint32(pix[cachedP+0])<<16 |
uint32(pix[cachedP+1])<<8 |
uint32(pix[cachedP+2])<<0 |
uint32(pix[cachedP+3])<<24
ccEntries[(argb*colorCacheMultiplier)>>ccShift] = argb
}
green -= nLiteralCodes + nLengthCodes
if int(green) >= len(ccEntries) {
return nil, errors.New("vp8l: invalid color cache index")
}
argb := ccEntries[green]
pix[p+0] = uint8(argb >> 16)
pix[p+1] = uint8(argb >> 8)
pix[p+2] = uint8(argb >> 0)
pix[p+3] = uint8(argb >> 24)
p += 4
x++
if x == w {
x, y = 0, y+1
}
lookupHG = hMask != 0 && x&hMask == 0
}
}
return pix, nil
}
// lz77Param returns the next LZ77 parameter: a length or a distance, specified
// in section 4.2.2.
func (d *decoder) lz77Param(symbol uint32) (uint32, error) {
if symbol < 4 {
return symbol + 1, nil
}
extraBits := (symbol - 2) >> 1
offset := (2 + symbol&1) << extraBits
n, err := d.read(extraBits)
if err != nil {
return 0, err
}
return offset + n + 1, nil
}
// decodeHeader decodes the VP8L header from r.
func decodeHeader(r io.Reader) (d *decoder, w int32, h int32, err error) {
rr, ok := r.(io.ByteReader)
if !ok {
rr = bufio.NewReader(r)
}
d = &decoder{r: rr}
magic, err := d.read(8)
if err != nil {
return nil, 0, 0, err
}
if magic != 0x2f {
return nil, 0, 0, errors.New("vp8l: invalid header")
}
width, err := d.read(14)
if err != nil {
return nil, 0, 0, err
}
width++
height, err := d.read(14)
if err != nil {
return nil, 0, 0, err
}
height++
_, err = d.read(1) // Read and ignore the hasAlpha hint.
if err != nil {
return nil, 0, 0, err
}
version, err := d.read(3)
if err != nil {
return nil, 0, 0, err
}
if version != 0 {
return nil, 0, 0, errors.New("vp8l: invalid version")
}
return d, int32(width), int32(height), nil
}
// DecodeConfig decodes the color model and dimensions of a VP8L image from r.
func DecodeConfig(r io.Reader) (image.Config, error) {
_, w, h, err := decodeHeader(r)
if err != nil {
return image.Config{}, err
}
return image.Config{
ColorModel: color.NRGBAModel,
Width: int(w),
Height: int(h),
}, nil
}
// Decode decodes a VP8L image from r.
func Decode(r io.Reader) (image.Image, error) {
d, w, h, err := decodeHeader(r)
if err != nil {
return nil, err
}
// Decode the transforms.
var (
nTransforms int
transforms [nTransformTypes]transform
transformsSeen [nTransformTypes]bool
originalW = w
)
for {
more, err := d.read(1)
if err != nil {
return nil, err
}
if more == 0 {
break
}
var t transform
t, w, err = d.decodeTransform(w, h)
if err != nil {
return nil, err
}
if transformsSeen[t.transformType] {
return nil, errors.New("vp8l: repeated transform")
}
transformsSeen[t.transformType] = true
transforms[nTransforms] = t
nTransforms++
}
// Decode the transformed pixels.
pix, err := d.decodePix(w, h, 0, true)
if err != nil {
return nil, err
}
// Apply the inverse transformations.
for i := nTransforms - 1; i >= 0; i-- {
t := &transforms[i]
pix = inverseTransforms[t.transformType](t, pix, h)
}
return &image.NRGBA{
Pix: pix,
Stride: 4 * int(originalW),
Rect: image.Rect(0, 0, int(originalW), int(h)),
}, nil
}

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@ -1,245 +0,0 @@
// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vp8l
import (
"io"
)
// reverseBits reverses the bits in a byte.
var reverseBits = [256]uint8{
0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff,
}
// hNode is a node in a Huffman tree.
type hNode struct {
// symbol is the symbol held by this node.
symbol uint32
// children, if positive, is the hTree.nodes index of the first of
// this node's two children. Zero means an uninitialized node,
// and -1 means a leaf node.
children int32
}
const leafNode = -1
// lutSize is the log-2 size of an hTree's look-up table.
const lutSize, lutMask = 7, 1<<7 - 1
// hTree is a Huffman tree.
type hTree struct {
// nodes are the nodes of the Huffman tree. During construction,
// len(nodes) grows from 1 up to cap(nodes) by steps of two.
// After construction, len(nodes) == cap(nodes), and both equal
// 2*theNumberOfSymbols - 1.
nodes []hNode
// lut is a look-up table for walking the nodes. The x in lut[x] is
// the next lutSize bits in the bit-stream. The low 8 bits of lut[x]
// equals 1 plus the number of bits in the next code, or 0 if the
// next code requires more than lutSize bits. The high 24 bits are:
// - the symbol, if the code requires lutSize or fewer bits, or
// - the hTree.nodes index to start the tree traversal from, if
// the next code requires more than lutSize bits.
lut [1 << lutSize]uint32
}
// insert inserts into the hTree a symbol whose encoding is the least
// significant codeLength bits of code.
func (h *hTree) insert(symbol uint32, code uint32, codeLength uint32) error {
if symbol > 0xffff || codeLength > 0xfe {
return errInvalidHuffmanTree
}
baseCode := uint32(0)
if codeLength > lutSize {
baseCode = uint32(reverseBits[(code>>(codeLength-lutSize))&0xff]) >> (8 - lutSize)
} else {
baseCode = uint32(reverseBits[code&0xff]) >> (8 - codeLength)
for i := 0; i < 1<<(lutSize-codeLength); i++ {
h.lut[baseCode|uint32(i)<<codeLength] = symbol<<8 | (codeLength + 1)
}
}
n := uint32(0)
for jump := lutSize; codeLength > 0; {
codeLength--
if int(n) > len(h.nodes) {
return errInvalidHuffmanTree
}
switch h.nodes[n].children {
case leafNode:
return errInvalidHuffmanTree
case 0:
if len(h.nodes) == cap(h.nodes) {
return errInvalidHuffmanTree
}
// Create two empty child nodes.
h.nodes[n].children = int32(len(h.nodes))
h.nodes = h.nodes[:len(h.nodes)+2]
}
n = uint32(h.nodes[n].children) + 1&(code>>codeLength)
jump--
if jump == 0 && h.lut[baseCode] == 0 {
h.lut[baseCode] = n << 8
}
}
switch h.nodes[n].children {
case leafNode:
// No-op.
case 0:
// Turn the uninitialized node into a leaf.
h.nodes[n].children = leafNode
default:
return errInvalidHuffmanTree
}
h.nodes[n].symbol = symbol
return nil
}
// codeLengthsToCodes returns the canonical Huffman codes implied by the
// sequence of code lengths.
func codeLengthsToCodes(codeLengths []uint32) ([]uint32, error) {
maxCodeLength := uint32(0)
for _, cl := range codeLengths {
if maxCodeLength < cl {
maxCodeLength = cl
}
}
const maxAllowedCodeLength = 15
if len(codeLengths) == 0 || maxCodeLength > maxAllowedCodeLength {
return nil, errInvalidHuffmanTree
}
histogram := [maxAllowedCodeLength + 1]uint32{}
for _, cl := range codeLengths {
histogram[cl]++
}
currCode, nextCodes := uint32(0), [maxAllowedCodeLength + 1]uint32{}
for cl := 1; cl < len(nextCodes); cl++ {
currCode = (currCode + histogram[cl-1]) << 1
nextCodes[cl] = currCode
}
codes := make([]uint32, len(codeLengths))
for symbol, cl := range codeLengths {
if cl > 0 {
codes[symbol] = nextCodes[cl]
nextCodes[cl]++
}
}
return codes, nil
}
// build builds a canonical Huffman tree from the given code lengths.
func (h *hTree) build(codeLengths []uint32) error {
// Calculate the number of symbols.
var nSymbols, lastSymbol uint32
for symbol, cl := range codeLengths {
if cl != 0 {
nSymbols++
lastSymbol = uint32(symbol)
}
}
if nSymbols == 0 {
return errInvalidHuffmanTree
}
h.nodes = make([]hNode, 1, 2*nSymbols-1)
// Handle the trivial case.
if nSymbols == 1 {
if len(codeLengths) <= int(lastSymbol) {
return errInvalidHuffmanTree
}
return h.insert(lastSymbol, 0, 0)
}
// Handle the non-trivial case.
codes, err := codeLengthsToCodes(codeLengths)
if err != nil {
return err
}
for symbol, cl := range codeLengths {
if cl > 0 {
if err := h.insert(uint32(symbol), codes[symbol], cl); err != nil {
return err
}
}
}
return nil
}
// buildSimple builds a Huffman tree with 1 or 2 symbols.
func (h *hTree) buildSimple(nSymbols uint32, symbols [2]uint32, alphabetSize uint32) error {
h.nodes = make([]hNode, 1, 2*nSymbols-1)
for i := uint32(0); i < nSymbols; i++ {
if symbols[i] >= alphabetSize {
return errInvalidHuffmanTree
}
if err := h.insert(symbols[i], i, nSymbols-1); err != nil {
return err
}
}
return nil
}
// next returns the next Huffman-encoded symbol from the bit-stream d.
func (h *hTree) next(d *decoder) (uint32, error) {
var n uint32
// Read enough bits so that we can use the look-up table.
if d.nBits < lutSize {
c, err := d.r.ReadByte()
if err != nil {
if err == io.EOF {
// There are no more bytes of data, but we may still be able
// to read the next symbol out of the previously read bits.
goto slowPath
}
return 0, err
}
d.bits |= uint32(c) << d.nBits
d.nBits += 8
}
// Use the look-up table.
n = h.lut[d.bits&lutMask]
if b := n & 0xff; b != 0 {
b--
d.bits >>= b
d.nBits -= b
return n >> 8, nil
}
n >>= 8
d.bits >>= lutSize
d.nBits -= lutSize
slowPath:
for h.nodes[n].children != leafNode {
if d.nBits == 0 {
c, err := d.r.ReadByte()
if err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return 0, err
}
d.bits = uint32(c)
d.nBits = 8
}
n = uint32(h.nodes[n].children) + 1&d.bits
d.bits >>= 1
d.nBits--
}
return h.nodes[n].symbol, nil
}

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@ -1,299 +0,0 @@
// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vp8l
// This file deals with image transforms, specified in section 3.
// nTiles returns the number of tiles needed to cover size pixels, where each
// tile's side is 1<<bits pixels long.
func nTiles(size int32, bits uint32) int32 {
return (size + 1<<bits - 1) >> bits
}
const (
transformTypePredictor = 0
transformTypeCrossColor = 1
transformTypeSubtractGreen = 2
transformTypeColorIndexing = 3
nTransformTypes = 4
)
// transform holds the parameters for an invertible transform.
type transform struct {
// transformType is the type of the transform.
transformType uint32
// oldWidth is the width of the image before transformation (or
// equivalently, after inverse transformation). The color-indexing
// transform can reduce the width. For example, a 50-pixel-wide
// image that only needs 4 bits (half a byte) per color index can
// be transformed into a 25-pixel-wide image.
oldWidth int32
// bits is the log-2 size of the transform's tiles, for the predictor
// and cross-color transforms. 8>>bits is the number of bits per
// color index, for the color-index transform.
bits uint32
// pix is the tile values, for the predictor and cross-color
// transforms, and the color palette, for the color-index transform.
pix []byte
}
var inverseTransforms = [nTransformTypes]func(*transform, []byte, int32) []byte{
transformTypePredictor: inversePredictor,
transformTypeCrossColor: inverseCrossColor,
transformTypeSubtractGreen: inverseSubtractGreen,
transformTypeColorIndexing: inverseColorIndexing,
}
func inversePredictor(t *transform, pix []byte, h int32) []byte {
if t.oldWidth == 0 || h == 0 {
return pix
}
// The first pixel's predictor is mode 0 (opaque black).
pix[3] += 0xff
p, mask := int32(4), int32(1)<<t.bits-1
for x := int32(1); x < t.oldWidth; x++ {
// The rest of the first row's predictor is mode 1 (L).
pix[p+0] += pix[p-4]
pix[p+1] += pix[p-3]
pix[p+2] += pix[p-2]
pix[p+3] += pix[p-1]
p += 4
}
top, tilesPerRow := 0, nTiles(t.oldWidth, t.bits)
for y := int32(1); y < h; y++ {
// The first column's predictor is mode 2 (T).
pix[p+0] += pix[top+0]
pix[p+1] += pix[top+1]
pix[p+2] += pix[top+2]
pix[p+3] += pix[top+3]
p, top = p+4, top+4
q := 4 * (y >> t.bits) * tilesPerRow
predictorMode := t.pix[q+1] & 0x0f
q += 4
for x := int32(1); x < t.oldWidth; x++ {
if x&mask == 0 {
predictorMode = t.pix[q+1] & 0x0f
q += 4
}
switch predictorMode {
case 0: // Opaque black.
pix[p+3] += 0xff
case 1: // L.
pix[p+0] += pix[p-4]
pix[p+1] += pix[p-3]
pix[p+2] += pix[p-2]
pix[p+3] += pix[p-1]
case 2: // T.
pix[p+0] += pix[top+0]
pix[p+1] += pix[top+1]
pix[p+2] += pix[top+2]
pix[p+3] += pix[top+3]
case 3: // TR.
pix[p+0] += pix[top+4]
pix[p+1] += pix[top+5]
pix[p+2] += pix[top+6]
pix[p+3] += pix[top+7]
case 4: // TL.
pix[p+0] += pix[top-4]
pix[p+1] += pix[top-3]
pix[p+2] += pix[top-2]
pix[p+3] += pix[top-1]
case 5: // Average2(Average2(L, TR), T).
pix[p+0] += avg2(avg2(pix[p-4], pix[top+4]), pix[top+0])
pix[p+1] += avg2(avg2(pix[p-3], pix[top+5]), pix[top+1])
pix[p+2] += avg2(avg2(pix[p-2], pix[top+6]), pix[top+2])
pix[p+3] += avg2(avg2(pix[p-1], pix[top+7]), pix[top+3])
case 6: // Average2(L, TL).
pix[p+0] += avg2(pix[p-4], pix[top-4])
pix[p+1] += avg2(pix[p-3], pix[top-3])
pix[p+2] += avg2(pix[p-2], pix[top-2])
pix[p+3] += avg2(pix[p-1], pix[top-1])
case 7: // Average2(L, T).
pix[p+0] += avg2(pix[p-4], pix[top+0])
pix[p+1] += avg2(pix[p-3], pix[top+1])
pix[p+2] += avg2(pix[p-2], pix[top+2])
pix[p+3] += avg2(pix[p-1], pix[top+3])
case 8: // Average2(TL, T).
pix[p+0] += avg2(pix[top-4], pix[top+0])
pix[p+1] += avg2(pix[top-3], pix[top+1])
pix[p+2] += avg2(pix[top-2], pix[top+2])
pix[p+3] += avg2(pix[top-1], pix[top+3])
case 9: // Average2(T, TR).
pix[p+0] += avg2(pix[top+0], pix[top+4])
pix[p+1] += avg2(pix[top+1], pix[top+5])
pix[p+2] += avg2(pix[top+2], pix[top+6])
pix[p+3] += avg2(pix[top+3], pix[top+7])
case 10: // Average2(Average2(L, TL), Average2(T, TR)).
pix[p+0] += avg2(avg2(pix[p-4], pix[top-4]), avg2(pix[top+0], pix[top+4]))
pix[p+1] += avg2(avg2(pix[p-3], pix[top-3]), avg2(pix[top+1], pix[top+5]))
pix[p+2] += avg2(avg2(pix[p-2], pix[top-2]), avg2(pix[top+2], pix[top+6]))
pix[p+3] += avg2(avg2(pix[p-1], pix[top-1]), avg2(pix[top+3], pix[top+7]))
case 11: // Select(L, T, TL).
l0 := int32(pix[p-4])
l1 := int32(pix[p-3])
l2 := int32(pix[p-2])
l3 := int32(pix[p-1])
c0 := int32(pix[top-4])
c1 := int32(pix[top-3])
c2 := int32(pix[top-2])
c3 := int32(pix[top-1])
t0 := int32(pix[top+0])
t1 := int32(pix[top+1])
t2 := int32(pix[top+2])
t3 := int32(pix[top+3])
l := abs(c0-t0) + abs(c1-t1) + abs(c2-t2) + abs(c3-t3)
t := abs(c0-l0) + abs(c1-l1) + abs(c2-l2) + abs(c3-l3)
if l < t {
pix[p+0] += uint8(l0)
pix[p+1] += uint8(l1)
pix[p+2] += uint8(l2)
pix[p+3] += uint8(l3)
} else {
pix[p+0] += uint8(t0)
pix[p+1] += uint8(t1)
pix[p+2] += uint8(t2)
pix[p+3] += uint8(t3)
}
case 12: // ClampAddSubtractFull(L, T, TL).
pix[p+0] += clampAddSubtractFull(pix[p-4], pix[top+0], pix[top-4])
pix[p+1] += clampAddSubtractFull(pix[p-3], pix[top+1], pix[top-3])
pix[p+2] += clampAddSubtractFull(pix[p-2], pix[top+2], pix[top-2])
pix[p+3] += clampAddSubtractFull(pix[p-1], pix[top+3], pix[top-1])
case 13: // ClampAddSubtractHalf(Average2(L, T), TL).
pix[p+0] += clampAddSubtractHalf(avg2(pix[p-4], pix[top+0]), pix[top-4])
pix[p+1] += clampAddSubtractHalf(avg2(pix[p-3], pix[top+1]), pix[top-3])
pix[p+2] += clampAddSubtractHalf(avg2(pix[p-2], pix[top+2]), pix[top-2])
pix[p+3] += clampAddSubtractHalf(avg2(pix[p-1], pix[top+3]), pix[top-1])
}
p, top = p+4, top+4
}
}
return pix
}
func inverseCrossColor(t *transform, pix []byte, h int32) []byte {
var greenToRed, greenToBlue, redToBlue int32
p, mask, tilesPerRow := int32(0), int32(1)<<t.bits-1, nTiles(t.oldWidth, t.bits)
for y := int32(0); y < h; y++ {
q := 4 * (y >> t.bits) * tilesPerRow
for x := int32(0); x < t.oldWidth; x++ {
if x&mask == 0 {
redToBlue = int32(int8(t.pix[q+0]))
greenToBlue = int32(int8(t.pix[q+1]))
greenToRed = int32(int8(t.pix[q+2]))
q += 4
}
red := pix[p+0]
green := pix[p+1]
blue := pix[p+2]
red += uint8(uint32(greenToRed*int32(int8(green))) >> 5)
blue += uint8(uint32(greenToBlue*int32(int8(green))) >> 5)
blue += uint8(uint32(redToBlue*int32(int8(red))) >> 5)
pix[p+0] = red
pix[p+2] = blue
p += 4
}
}
return pix
}
func inverseSubtractGreen(t *transform, pix []byte, h int32) []byte {
for p := 0; p < len(pix); p += 4 {
green := pix[p+1]
pix[p+0] += green
pix[p+2] += green
}
return pix
}
func inverseColorIndexing(t *transform, pix []byte, h int32) []byte {
if t.bits == 0 {
for p := 0; p < len(pix); p += 4 {
i := 4 * uint32(pix[p+1])
pix[p+0] = t.pix[i+0]
pix[p+1] = t.pix[i+1]
pix[p+2] = t.pix[i+2]
pix[p+3] = t.pix[i+3]
}
return pix
}
vMask, xMask, bitsPerPixel := uint32(0), int32(0), uint32(8>>t.bits)
switch t.bits {
case 1:
vMask, xMask = 0x0f, 0x01
case 2:
vMask, xMask = 0x03, 0x03
case 3:
vMask, xMask = 0x01, 0x07
}
d, p, v, dst := 0, 0, uint32(0), make([]byte, 4*t.oldWidth*h)
for y := int32(0); y < h; y++ {
for x := int32(0); x < t.oldWidth; x++ {
if x&xMask == 0 {
v = uint32(pix[p+1])
p += 4
}
i := 4 * (v & vMask)
dst[d+0] = t.pix[i+0]
dst[d+1] = t.pix[i+1]
dst[d+2] = t.pix[i+2]
dst[d+3] = t.pix[i+3]
d += 4
v >>= bitsPerPixel
}
}
return dst
}
func abs(x int32) int32 {
if x < 0 {
return -x
}
return x
}
func avg2(a, b uint8) uint8 {
return uint8((int32(a) + int32(b)) / 2)
}
func clampAddSubtractFull(a, b, c uint8) uint8 {
x := int32(a) + int32(b) - int32(c)
if x < 0 {
return 0
}
if x > 255 {
return 255
}
return uint8(x)
}
func clampAddSubtractHalf(a, b uint8) uint8 {
x := int32(a) + (int32(a)-int32(b))/2
if x < 0 {
return 0
}
if x > 255 {
return 255
}
return uint8(x)
}

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@ -1,272 +0,0 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build go1.6
package webp
import (
"bytes"
"errors"
"image"
"image/color"
"io"
"golang.org/x/image/riff"
"golang.org/x/image/vp8"
"golang.org/x/image/vp8l"
)
var errInvalidFormat = errors.New("webp: invalid format")
var (
fccALPH = riff.FourCC{'A', 'L', 'P', 'H'}
fccVP8 = riff.FourCC{'V', 'P', '8', ' '}
fccVP8L = riff.FourCC{'V', 'P', '8', 'L'}
fccVP8X = riff.FourCC{'V', 'P', '8', 'X'}
fccWEBP = riff.FourCC{'W', 'E', 'B', 'P'}
)
func decode(r io.Reader, configOnly bool) (image.Image, image.Config, error) {
formType, riffReader, err := riff.NewReader(r)
if err != nil {
return nil, image.Config{}, err
}
if formType != fccWEBP {
return nil, image.Config{}, errInvalidFormat
}
var (
alpha []byte
alphaStride int
wantAlpha bool
widthMinusOne uint32
heightMinusOne uint32
buf [10]byte
)
for {
chunkID, chunkLen, chunkData, err := riffReader.Next()
if err == io.EOF {
err = errInvalidFormat
}
if err != nil {
return nil, image.Config{}, err
}
switch chunkID {
case fccALPH:
if !wantAlpha {
return nil, image.Config{}, errInvalidFormat
}
wantAlpha = false
// Read the Pre-processing | Filter | Compression byte.
if _, err := io.ReadFull(chunkData, buf[:1]); err != nil {
if err == io.EOF {
err = errInvalidFormat
}
return nil, image.Config{}, err
}
alpha, alphaStride, err = readAlpha(chunkData, widthMinusOne, heightMinusOne, buf[0]&0x03)
if err != nil {
return nil, image.Config{}, err
}
unfilterAlpha(alpha, alphaStride, (buf[0]>>2)&0x03)
case fccVP8:
if wantAlpha || int32(chunkLen) < 0 {
return nil, image.Config{}, errInvalidFormat
}
d := vp8.NewDecoder()
d.Init(chunkData, int(chunkLen))
fh, err := d.DecodeFrameHeader()
if err != nil {
return nil, image.Config{}, err
}
if configOnly {
return nil, image.Config{
ColorModel: color.YCbCrModel,
Width: fh.Width,
Height: fh.Height,
}, nil
}
m, err := d.DecodeFrame()
if err != nil {
return nil, image.Config{}, err
}
if alpha != nil {
return &image.NYCbCrA{
YCbCr: *m,
A: alpha,
AStride: alphaStride,
}, image.Config{}, nil
}
return m, image.Config{}, nil
case fccVP8L:
if wantAlpha || alpha != nil {
return nil, image.Config{}, errInvalidFormat
}
if configOnly {
c, err := vp8l.DecodeConfig(chunkData)
return nil, c, err
}
m, err := vp8l.Decode(chunkData)
return m, image.Config{}, err
case fccVP8X:
if chunkLen != 10 {
return nil, image.Config{}, errInvalidFormat
}
if _, err := io.ReadFull(chunkData, buf[:10]); err != nil {
return nil, image.Config{}, err
}
const (
animationBit = 1 << 1
xmpMetadataBit = 1 << 2
exifMetadataBit = 1 << 3
alphaBit = 1 << 4
iccProfileBit = 1 << 5
)
if buf[0] != alphaBit {
return nil, image.Config{}, errors.New("webp: non-Alpha VP8X is not implemented")
}
widthMinusOne = uint32(buf[4]) | uint32(buf[5])<<8 | uint32(buf[6])<<16
heightMinusOne = uint32(buf[7]) | uint32(buf[8])<<8 | uint32(buf[9])<<16
if configOnly {
return nil, image.Config{
ColorModel: color.NYCbCrAModel,
Width: int(widthMinusOne) + 1,
Height: int(heightMinusOne) + 1,
}, nil
}
wantAlpha = true
default:
return nil, image.Config{}, errInvalidFormat
}
}
}
func readAlpha(chunkData io.Reader, widthMinusOne, heightMinusOne uint32, compression byte) (
alpha []byte, alphaStride int, err error) {
switch compression {
case 0:
w := int(widthMinusOne) + 1
h := int(heightMinusOne) + 1
alpha = make([]byte, w*h)
if _, err := io.ReadFull(chunkData, alpha); err != nil {
return nil, 0, err
}
return alpha, w, nil
case 1:
// Read the VP8L-compressed alpha values. First, synthesize a 5-byte VP8L header:
// a 1-byte magic number, a 14-bit widthMinusOne, a 14-bit heightMinusOne,
// a 1-bit (ignored, zero) alphaIsUsed and a 3-bit (zero) version.
// TODO(nigeltao): be more efficient than decoding an *image.NRGBA just to
// extract the green values to a separately allocated []byte. Fixing this
// will require changes to the vp8l package's API.
if widthMinusOne > 0x3fff || heightMinusOne > 0x3fff {
return nil, 0, errors.New("webp: invalid format")
}
alphaImage, err := vp8l.Decode(io.MultiReader(
bytes.NewReader([]byte{
0x2f, // VP8L magic number.
uint8(widthMinusOne),
uint8(widthMinusOne>>8) | uint8(heightMinusOne<<6),
uint8(heightMinusOne >> 2),
uint8(heightMinusOne >> 10),
}),
chunkData,
))
if err != nil {
return nil, 0, err
}
// The green values of the inner NRGBA image are the alpha values of the
// outer NYCbCrA image.
pix := alphaImage.(*image.NRGBA).Pix
alpha = make([]byte, len(pix)/4)
for i := range alpha {
alpha[i] = pix[4*i+1]
}
return alpha, int(widthMinusOne) + 1, nil
}
return nil, 0, errInvalidFormat
}
func unfilterAlpha(alpha []byte, alphaStride int, filter byte) {
if len(alpha) == 0 || alphaStride == 0 {
return
}
switch filter {
case 1: // Horizontal filter.
for i := 1; i < alphaStride; i++ {
alpha[i] += alpha[i-1]
}
for i := alphaStride; i < len(alpha); i += alphaStride {
// The first column is equivalent to the vertical filter.
alpha[i] += alpha[i-alphaStride]
for j := 1; j < alphaStride; j++ {
alpha[i+j] += alpha[i+j-1]
}
}
case 2: // Vertical filter.
// The first row is equivalent to the horizontal filter.
for i := 1; i < alphaStride; i++ {
alpha[i] += alpha[i-1]
}
for i := alphaStride; i < len(alpha); i++ {
alpha[i] += alpha[i-alphaStride]
}
case 3: // Gradient filter.
// The first row is equivalent to the horizontal filter.
for i := 1; i < alphaStride; i++ {
alpha[i] += alpha[i-1]
}
for i := alphaStride; i < len(alpha); i += alphaStride {
// The first column is equivalent to the vertical filter.
alpha[i] += alpha[i-alphaStride]
// The interior is predicted on the three top/left pixels.
for j := 1; j < alphaStride; j++ {
c := int(alpha[i+j-alphaStride-1])
b := int(alpha[i+j-alphaStride])
a := int(alpha[i+j-1])
x := a + b - c
if x < 0 {
x = 0
} else if x > 255 {
x = 255
}
alpha[i+j] += uint8(x)
}
}
}
}
// Decode reads a WEBP image from r and returns it as an image.Image.
func Decode(r io.Reader) (image.Image, error) {
m, _, err := decode(r, false)
if err != nil {
return nil, err
}
return m, err
}
// DecodeConfig returns the color model and dimensions of a WEBP image without
// decoding the entire image.
func DecodeConfig(r io.Reader) (image.Config, error) {
_, c, err := decode(r, true)
return c, err
}
func init() {
image.RegisterFormat("webp", "RIFF????WEBPVP8", Decode, DecodeConfig)
}

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@ -1,30 +0,0 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package webp implements a decoder for WEBP images.
//
// WEBP is defined at:
// https://developers.google.com/speed/webp/docs/riff_container
//
// It requires Go 1.6 or later.
package webp // import "golang.org/x/image/webp"
// This blank Go file, other than the package clause, exists so that this
// package can be built for Go 1.5 and earlier. (The other files in this
// package are all marked "+build go1.6" for the NYCbCrA types introduced in Go
// 1.6). There is no functionality in a blank package, but some image
// manipulation programs might still underscore import this package for the
// side effect of registering the WEBP format with the standard library's
// image.RegisterFormat and image.Decode functions. For example, that program
// might contain:
//
// // Underscore imports to register some formats for image.Decode.
// import _ "image/gif"
// import _ "image/jpeg"
// import _ "image/png"
// import _ "golang.org/x/image/webp"
//
// Such a program will still compile for Go 1.5 (due to this placeholder Go
// file). It will simply not be able to recognize and decode WEBP (but still
// handle GIF, JPEG and PNG).

13
vendor/modules.txt vendored
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@ -1,13 +0,0 @@
# code.ivysaur.me/imagequant v2.12.2-go1.2+incompatible
code.ivysaur.me/imagequant
# github.com/hashicorp/golang-lru v0.5.0
github.com/hashicorp/golang-lru
github.com/hashicorp/golang-lru/simplelru
# golang.org/x/image v0.0.0-20180601115456-af66defab954
golang.org/x/image/bmp
golang.org/x/image/draw
golang.org/x/image/webp
golang.org/x/image/math/f64
golang.org/x/image/riff
golang.org/x/image/vp8
golang.org/x/image/vp8l