diff --git a/thumbnail/Thumbnailer.go b/thumbnail/Thumbnailer.go
index 94d6625..6ea2e98 100644
--- a/thumbnail/Thumbnailer.go
+++ b/thumbnail/Thumbnailer.go
@@ -92,18 +92,18 @@ func FiletypeSupported(ext string) bool {
 }
 
 func (this *Thumbnailer) RenderFile_NoCache(absPath string) ([]byte, error) {
+	return this.RenderFile_NoCache_MimeType(absPath, mime.TypeByExtension(filepath.Ext(absPath)))
+}
+
+func (this *Thumbnailer) RenderFile_NoCache_MimeType(absPath, mimeType string) ([]byte, error) {
 
 	fh, err := os.OpenFile(absPath, os.O_RDONLY, 0400)
 	if err != nil {
 		return nil, err
 	}
-
 	defer fh.Close()
 
-	extension := strings.ToLower(filepath.Ext(absPath))
-
-	switch extension {
-	case ".jpg", ".jpeg":
+	if mimeType == `image/jpeg` {
 		src, err := jpeg.Decode(fh)
 		if err != nil {
 			return nil, err
@@ -111,7 +111,7 @@ func (this *Thumbnailer) RenderFile_NoCache(absPath string) ([]byte, error) {
 
 		return this.RenderScaledImage(src)
 
-	case ".png":
+	} else if mimeType == `image/png` {
 		src, err := png.Decode(fh)
 		if err != nil {
 			return nil, err
@@ -119,7 +119,7 @@ func (this *Thumbnailer) RenderFile_NoCache(absPath string) ([]byte, error) {
 
 		return this.RenderScaledImage(src)
 
-	case ".gif":
+	} else if mimeType == `image/gif` {
 		src, err := gif.Decode(fh)
 		if err != nil {
 			return nil, err
@@ -127,10 +127,10 @@ func (this *Thumbnailer) RenderFile_NoCache(absPath string) ([]byte, error) {
 
 		return this.RenderScaledImage(src)
 
-	case ".avi", ".mkv", ".mp4", ".ogm", ".wmv", ".flv", ".rm", ".rmvb":
+	} else if strings.HasPrefix(mimeType, `video/`) {
 		return this.RenderScaledFfmpeg(absPath)
 
-	default:
+	} else {
 		return nil, ErrUnsupportedFiletype
 
 	}