// EncodeRGBA encodes and writes image.Image into the writer as WebP.
// Now supports image.RGBA or image.NRGBA.
func EncodeRGBA(w io.Writer, img image.Image, c Config) (err error) {
webpConfig, err := initConfig(c)
if err != nil {
return
}
var pic C.WebPPicture
if C.WebPPictureInit(&pic) == 0 {
return errors.New("Could not initialize webp picture")
}
pic.use_argb = 1
pic.width = C.int(img.Bounds().Dx())
pic.height = C.int(img.Bounds().Dy())
pic.writer = C.WebPWriterFunction(C.writeWebP)
pic.custom_ptr = unsafe.Pointer(&destinationManager{writer: w})
switch p := img.(type) {
case *image.RGBA:
C.WebPPictureImportRGBA(&pic, (*C.uint8_t)(&p.Pix[0]), C.int(p.Stride))
case *image.NRGBA:
C.WebPPictureImportRGBA(&pic, (*C.uint8_t)(&p.Pix[0]), C.int(p.Stride))
default:
return errors.New("unsupported image type")
}
defer C.WebPPictureFree(&pic)
if C.WebPEncode(webpConfig, &pic) == 0 {
return fmt.Errorf("Encoding error: %d", pic.error_code)
}
return
}
// EncodeYUVA encodes and writes YUVA Image data into the writer as WebP.
func EncodeYUVA(w io.Writer, img *YUVAImage, c Config) (err error) {
webpConfig, err := initConfig(c)
if err != nil {
return
}
var pic C.WebPPicture
if C.WebPPictureInit(&pic) == 0 {
return errors.New("Could not initialize webp picture")
}
pic.use_argb = 0
pic.colorspace = C.WebPEncCSP(img.ColorSpace)
pic.width = C.int(img.Rect.Dx())
pic.height = C.int(img.Rect.Dy())
pic.y = (*C.uint8_t)(&img.Y[0])
pic.u = (*C.uint8_t)(&img.Cb[0])
pic.v = (*C.uint8_t)(&img.Cr[0])
pic.y_stride = C.int(img.YStride)
pic.uv_stride = C.int(img.CStride)
if img.ColorSpace == YUV420A {
pic.a = (*C.uint8_t)(&img.A[0])
pic.a_stride = C.int(img.AStride)
}
pic.writer = C.WebPWriterFunction(C.writeWebP)
pic.custom_ptr = unsafe.Pointer(&destinationManager{writer: w})
if C.WebPEncode(webpConfig, &pic) == 0 {
return fmt.Errorf("Encoding error: %d", pic.error_code)
}
return
}