Merge pull request #57 from pixiv/feature/support_encoding_rgb_jpeg

Support encoding rgb.Image.

jpeg/compress.go

@@ -144,6 +144,8 @@ import (
 	"image"
 	"io"
 	"unsafe"
+
+	"github.com/pixiv/go-libjpeg/rgb"
 )
 
 // EncoderOptions specifies which settings to use during Compression.
@@ -235,6 +237,8 @@ func Encode(w io.Writer, src image.Image, opt *EncoderOptions) (err error) {
 		err = encodeGray(cinfo, s, opt)
 	case *image.RGBA:
 		err = encodeRGBA(cinfo, s, opt)
+	case *rgb.Image:
+		err = encodeRGB(cinfo, s, opt)
 	default:
 		return errors.New("unsupported image type")
 	}
@@ -350,6 +354,39 @@ func encodeRGBA(cinfo *C.struct_jpeg_compress_struct, src *image.RGBA, p *Encode
 	return
 }
 
+// encode rgb.Image.
+func encodeRGB(cinfo *C.struct_jpeg_compress_struct, src *rgb.Image, p *EncoderOptions) (err error) {
+	// Set up compression parameters
+	w, h := src.Bounds().Dx(), src.Bounds().Dy()
+	cinfo.image_width = C.JDIMENSION(w)
+	cinfo.image_height = C.JDIMENSION(h)
+	cinfo.input_components = 3
+	cinfo.in_color_space = C.JCS_RGB
+
+	setupEncoderOptions(cinfo, p)
+
+	// Start compression
+	err = startCompress(cinfo)
+	if err != nil {
+		return
+	}
+	defer func() {
+		ferr := finishCompress(cinfo)
+		if ferr != nil && err == nil {
+			err = ferr
+		}
+	}()
+
+	for v := 0; v < h; {
+		line, err := writeScanline(cinfo, C.JSAMPROW(unsafe.Pointer(&src.Pix[v*src.Stride])), C.JDIMENSION(1))
+		if err != nil {
+			return err
+		}
+		v += line
+	}
+	return
+}
+
 // encode image.Gray
 func encodeGray(cinfo *C.struct_jpeg_compress_struct, src *image.Gray, p *EncoderOptions) (err error) {
 	// Set up compression parameters

jpeg/issue51_test.go

@@ -7,13 +7,13 @@ import (
 	"github.com/pixiv/go-libjpeg/jpeg"
 )
 
-var data = []byte("\xff\xd8\xff\xdb\x00C\x000000000000000" +
-	"00000000000000000000" +
-	"00000000000000000000" +
-	"00000000000\xff\xc9\x00\v\b00\x000" +
-	"\x01\x01\x14\x00\xff\xda\x00\b\x01\x010\x00?\x0000")
-
 // https://github.com/pixiv/go-libjpeg/issues/51
 func TestIssue51(t *testing.T) {
+	data := []byte("\xff\xd8\xff\xdb\x00C\x000000000000000" +
+		"00000000000000000000" +
+		"00000000000000000000" +
+		"00000000000\xff\xc9\x00\v\b00\x000" +
+		"\x01\x01\x14\x00\xff\xda\x00\b\x01\x010\x00?\x0000")
+
 	jpeg.Decode(bytes.NewReader(data), &jpeg.DecoderOptions{})
 }

jpeg/issue55_test.go

@@ -0,0 +1,30 @@
+package jpeg_test
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/pixiv/go-libjpeg/jpeg"
+)
+
+// https://github.com/pixiv/go-libjpeg/issues/55
+func TestDecodeAndEncodeRGBJPEG(t *testing.T) {
+	data := []byte("\xff\xd8\xff\xdb\x00C\x000000000000000" +
+		"00000000000000000000" +
+		"00000000000000000000" +
+		"00000000000\xff\xc0\x00\x11\b\x00000" +
+		"\x03R\"\x00G\x11\x00B\x11\x00\xff\xda\x00\f\x03R\x00G\x00B" +
+		"\x00")
+
+	img, err := jpeg.Decode(bytes.NewReader(data), &jpeg.DecoderOptions{})
+	if err != nil {
+		t.Log(err)
+		return
+	}
+
+	var w bytes.Buffer
+	err = jpeg.Encode(&w, img, &jpeg.EncoderOptions{})
+	if err != nil {
+		t.Errorf("encoding after decoding failed: %v", err)
+	}
+}