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set custom output/aspect/scale formats, add package-level error vars

This commit is contained in:
mappu 2016-12-05 21:48:48 +13:00
parent 95da07dbb9
commit 67c50a0539
3 changed files with 102 additions and 31 deletions
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45
Thumbnailer.go
View File

@ -1,7 +1,7 @@
package thumbnail
import (
"fmt"
"errors"
"image/gif"
"image/jpeg"
"image/png"
@ -12,22 +12,55 @@ import (
lru "github.com/hashicorp/golang-lru"
)
type OutputFormat uint8
type AspectFormat uint8
type ScaleFormat uint8
const (
OUTPUT_PNG_CRUSH OutputFormat = 2
OUTPUT_JPG OutputFormat = 3
OUTPUT__DEFAULT = OUTPUT_PNG_CRUSH
ASPECT_PADDED AspectFormat = 80
ASPECT_SVELTE AspectFormat = 81
ASPECT__DEFAULT = ASPECT_PADDED
SCALEFMT_NN ScaleFormat = 120
SCALEFMT_BILINEAR ScaleFormat = 121
SCALEFMT__DEFAULT = SCALEFMT_BILINEAR
)
var (
ErrInvalidOption error = errors.New("Invalid format parameter")
ErrUnsupportedFiletype error = errors.New("Unsupported filetype")
)
type Thumbnailer struct {
Width int
Height int
width int
height int
ofmt OutputFormat
afmt AspectFormat
sfmt ScaleFormat
thumbCache *lru.Cache // threadsafe
}
func NewThumbnailer(Width, Height, MaxCacheSize int) *Thumbnailer {
return NewThumbnailerEx(Width, Height, MaxCacheSize, OUTPUT__DEFAULT, ASPECT__DEFAULT, SCALEFMT__DEFAULT)
}
func NewThumbnailerEx(Width, Height, MaxCacheSize int, of OutputFormat, af AspectFormat, sf ScaleFormat) *Thumbnailer {
thumbCache, err := lru.New(MaxCacheSize)
if err != nil {
panic(err)
}
return &Thumbnailer{
Width: Width,
Height: Height,
width: Width,
height: Height,
ofmt: of,
afmt: af,
sfmt: sf,
thumbCache: thumbCache,
}
}
@ -98,7 +131,7 @@ func (this *Thumbnailer) RenderFile_NoCache(absPath string) ([]byte, error) {
return this.RenderScaledFfmpeg(absPath)
default:
return nil, fmt.Errorf("No thumbnailer for file type '%s'", extension)
return nil, ErrUnsupportedFiletype
}

70
image.go
View File

@ -1,7 +1,9 @@
package thumbnail
import (
"bytes"
"image"
"image/jpeg"
"code.ivysaur.me/imagequant"
)
@ -13,41 +15,65 @@ func (this *Thumbnailer) RenderScaledImage(src image.Image) ([]byte, error) {
destH := 0
if srcW > srcH {
destW = this.Width
destH = this.Height * srcH / srcW
destW = this.width
destH = this.height * srcH / srcW
} else {
destW = this.Width * srcW / srcH
destH = this.Height
destW = this.width * srcW / srcH
destH = this.height
}
offsetX := (this.Width - destW) / 2
offsetY := (this.Height - destH) / 2
offsetX := (this.width - destW) / 2
offsetY := (this.height - destH) / 2
scaleW := float64(srcW) / float64(destW)
scaleH := float64(srcH) / float64(destH)
dest := image.NewRGBA(image.Rectangle{Max: image.Point{X: this.Width, Y: this.Height}})
dest := image.NewRGBA(image.Rectangle{Max: image.Point{X: this.width, Y: this.height}})
for y := 0; y < destH; y += 1 {
for x := 0; x < destW; x += 1 {
switch this.sfmt {
/*
// NN
case SCALEFMT_BILINEAR:
for y := 0; y < destH; y += 1 {
for x := 0; x < destW; x += 1 {
c00 := src.At(int(float64(x)*scaleW), int(float64(y)*scaleH))
c01 := src.At(int((float64(x)+0.5)*scaleW), int(float64(y)*scaleH))
c10 := src.At(int(float64(x)*scaleW), int((float64(y)+0.5)*scaleH))
c11 := src.At(int((float64(x)+0.5)*scaleW), int((float64(y)+0.5)*scaleH))
cBlend := Blend(Blend(c00, c01), Blend(c10, c11))
dest.Set(x+offsetX, y+offsetY, cBlend)
}
}
case SCALEFMT_NN:
for y := 0; y < destH; y += 1 {
for x := 0; x < destW; x += 1 {
mapx := int(float64(x) * scaleW)
mapy := int(float64(y) * scaleH)
dest.Set(x+offsetX, y+offsetY, src.At(mapx, mapy))
*/
// Bilinear
c00 := src.At(int(float64(x)*scaleW), int(float64(y)*scaleH))
c01 := src.At(int((float64(x)+0.5)*scaleW), int(float64(y)*scaleH))
c10 := src.At(int(float64(x)*scaleW), int((float64(y)+0.5)*scaleH))
c11 := src.At(int((float64(x)+0.5)*scaleW), int((float64(y)+0.5)*scaleH))
cBlend := Blend(Blend(c00, c01), Blend(c10, c11))
dest.Set(x+offsetX, y+offsetY, cBlend)
}
}
}
switch this.ofmt {
case OUTPUT_PNG_CRUSH:
return crush(dest, imagequant.SPEED_FASTEST)
case OUTPUT_JPG:
buff := bytes.Buffer{}
err := jpeg.Encode(&buff, dest, &jpeg.Options{Quality: jpeg.DefaultQuality})
if err != nil {
return nil, err
}
return buff.Bytes(), nil
default:
return nil, ErrInvalidOption
}
return crush(dest, imagequant.SPEED_FASTEST)
}

18
video.go
View File

@ -11,10 +11,22 @@ func (this *Thumbnailer) RenderScaledFfmpeg(absPath string) ([]byte, error) {
scaleCmd := fmt.Sprintf(
`thumbnail,scale='if(gt(a,%d/%d),%d,-1)':'if(gt(a,%d/%d),-1,%d)'`,
this.Height, this.Width, this.Height,
this.Height, this.Width, this.Width,
this.height, this.width, this.height,
this.height, this.width, this.width,
)
// BUG(): always produces ASPECT_SVELTE shape - need to re-pad for ASPECT_PADDED
var vcodec string
switch this.ofmt {
case OUTPUT_JPG:
vcodec = "jpg"
case OUTPUT_PNG_CRUSH:
vcodec = "png"
default:
return nil, ErrInvalidOption
}
cmd := exec.Command(
"ffmpeg",
"-loglevel", "0",
@ -23,7 +35,7 @@ func (this *Thumbnailer) RenderScaledFfmpeg(absPath string) ([]byte, error) {
"-vf", scaleCmd,
"-frames:v", "1",
"-f", "image2pipe",
"-c:v", "png",
"-c:v", vcodec,
"-",
)