added JPEG and PNG decoding

webcam.go

@@ -1,8 +1,12 @@
 package webcam
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
+	"image"
+	"image/jpeg"
+	"image/png"
 	"os"
 	"sort"
 	"syscall"
@@ -84,13 +88,6 @@ type buffer struct {
 	reserved  uint32
 }
 
-type format_dummy struct {
-	t   uint32
-	fmt struct {
-		raw_data [201]byte
-	}
-}
-
 type format struct {
 	t        uint32
 	pix      pix
@@ -264,13 +261,13 @@ func (s FrameSize) String() string {
 
 type FrameSizes []FrameSize
 
-func (slice FrameSizes) Len() int { return len(slice) }
-func (slice FrameSizes) Less(i, j int) bool {
-	ls := slice[i].MaxWidth * slice[i].MaxHeight
-	rs := slice[j].MaxWidth * slice[j].MaxHeight
+func (fs FrameSizes) Len() int { return len(fs) }
+func (fs FrameSizes) Less(i, j int) bool {
+	ls := fs[i].MaxWidth * fs[i].MaxHeight
+	rs := fs[j].MaxWidth * fs[j].MaxHeight
 	return ls < rs
 }
-func (slice FrameSizes) Swap(i, j int) { slice[i], slice[j] = slice[j], slice[i] }
+func (fs FrameSizes) Swap(i, j int) { fs[i], fs[j] = fs[j], fs[i] }
 
 func (w *Webcam) GetFrameSizes(code uint32) (fs FrameSizes) {
 	var s FrameSize
@@ -434,6 +431,22 @@ func (w *Webcam) ReadFrame() ([]byte, error) {
 	return buf, nil
 }
 
+func (w *Webcam) ReadJPEG() (image.Image, error) {
+	buf, err := w.ReadFrame()
+	if err != nil {
+		return nil, err
+	}
+	return jpeg.Decode(bytes.NewBuffer(buf))
+}
+
+func (w *Webcam) ReadPNG() (image.Image, error) {
+	buf, err := w.ReadFrame()
+	if err != nil {
+		return nil, err
+	}
+	return png.Decode(bytes.NewBuffer(buf))
+}
+
 func (w *Webcam) Close() error {
 	if err := w.mmapReleaseBuffers(); err != nil {
 		return err