Add support for YUYV/YUY2 format

camera/camera.go

@@ -1,5 +1,11 @@
 package camera
 
+import (
+	"bytes"
+	"fmt"
+	"image"
+)
+
 // Options .
 type Options struct {
 	Index      int
@@ -10,3 +16,84 @@ type Options struct {
 	Timestamp  bool
 	TimeFormat string
 }
+
+var (
+	yuy2FourCC = fourcc("YUY2")
+	yuyvFourCC = fourcc("YUYV")
+	mjpgFourCC = fourcc("MJPG")
+)
+
+func fourcc(b string) uint32 {
+	return uint32(b[0]) | (uint32(b[1]) << 8) | (uint32(b[2]) << 16) | (uint32(b[3]) << 24)
+}
+
+func bmp24ToRgba(data []byte, dst *image.RGBA) error {
+	r := bytes.NewReader(data)
+
+	width := dst.Bounds().Dx()
+	height := dst.Bounds().Dy()
+
+	// There are 3 bytes per pixel, and each row is 4-byte aligned.
+	b := make([]byte, (3*width+3)&^3)
+
+	// BMP images are stored bottom-up rather than top-down.
+	for y := height - 1; y >= 0; y-- {
+		_, err := r.Read(b)
+		if err != nil {
+			return err
+		}
+
+		p := dst.Pix[y*dst.Stride : y*dst.Stride+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 nil
+}
+
+// yuy2ToYCbCr422 converts a YUY2 (YUYV) byte slice to an image.YCbCr with YCbCrSubsampleRatio422 (I422).
+func yuy2ToYCbCr422(data []byte, dst *image.YCbCr) error {
+	if dst.SubsampleRatio != image.YCbCrSubsampleRatio422 {
+		return fmt.Errorf("subsample ratio must be 422, got %s", dst.SubsampleRatio.String())
+	}
+
+	width := dst.Bounds().Dx()
+	height := dst.Bounds().Dy()
+
+	if width%2 != 0 {
+		return fmt.Errorf("width must be even for YUY2")
+	}
+
+	if len(data) != width*height*2 {
+		return fmt.Errorf("invalid data length for YUY2")
+	}
+
+	stride := width * 2 // 2 bytes per pixel
+
+	for y := 0; y < height; y++ {
+		for x := 0; x < width; x += 2 {
+			idx := y*stride + x*2
+
+			y0 := data[idx+0]
+			cb := data[idx+1]
+			y1 := data[idx+2]
+			cr := data[idx+3]
+
+			// Y plane: every pixel
+			dst.Y[y*dst.YStride+x+0] = y0
+			dst.Y[y*dst.YStride+x+1] = y1
+
+			// Cb/Cr plane: every 2 pixels (422)
+			off := y*dst.CStride + x/2
+			dst.Cb[off] = cb
+			dst.Cr[off] = cr
+		}
+	}
+
+	return nil
+}