X-Git-Url: https://git.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fimage.cc;h=cb03e1a7304a160e5459dbac8602372f6f7d93b6;hb=f59ae2d9793699fd0e18f9e53ff362c26c2ef00c;hp=827ece5fdc97e25fd1aeecbde31547db0827aa99;hpb=1d7a98b5c7537b4874645c56cd83ece9f78625f5;p=dcpomatic.git

diff --git a/src/lib/image.cc b/src/lib/image.cc
index 827ece5fd..cb03e1a73 100644
--- a/src/lib/image.cc
+++ b/src/lib/image.cc
@@ -429,7 +429,7 @@ Image::make_black ()
 void
 Image::make_transparent ()
 {
-	if (_pixel_format != AV_PIX_FMT_RGBA) {
+	if (_pixel_format != AV_PIX_FMT_BGRA) {
 		throw PixelFormatError ("make_transparent()", _pixel_format);
 	}
 
@@ -439,8 +439,8 @@ Image::make_transparent ()
 void
 Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
 {
-	/* We're blending RGBA images; first byte is red, second byte is green, third byte blue, fourth byte alpha */
-	DCPOMATIC_ASSERT (other->pixel_format() == AV_PIX_FMT_RGBA);
+	/* We're blending BGRA images; first byte is blue, second byte is green, third byte red, fourth byte alpha */
+	DCPOMATIC_ASSERT (other->pixel_format() == AV_PIX_FMT_BGRA);
 	int const other_bpp = 4;
 
 	int start_tx = position.x;
@@ -469,9 +469,9 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
 			uint8_t* op = other->data()[0] + oy * other->stride()[0];
 			for (int tx = start_tx, ox = start_ox; tx < size().width && ox < other->size().width; ++tx, ++ox) {
 				float const alpha = float (op[3]) / 255;
-				tp[0] = op[0] * alpha + tp[0] * (1 - alpha);
+				tp[0] = op[2] * alpha + tp[0] * (1 - alpha);
 				tp[1] = op[1] * alpha + tp[1] * (1 - alpha);
-				tp[2] = op[2] * alpha + tp[2] * (1 - alpha);
+				tp[2] = op[0] * alpha + tp[2] * (1 - alpha);
 
 				tp += this_bpp;
 				op += other_bpp;
@@ -487,9 +487,9 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
 			uint8_t* op = other->data()[0] + oy * other->stride()[0];
 			for (int tx = start_tx, ox = start_ox; tx < size().width && ox < other->size().width; ++tx, ++ox) {
 				float const alpha = float (op[3]) / 255;
-				tp[0] = op[2] * alpha + tp[0] * (1 - alpha);
+				tp[0] = op[0] * alpha + tp[0] * (1 - alpha);
 				tp[1] = op[1] * alpha + tp[1] * (1 - alpha);
-				tp[2] = op[0] * alpha + tp[2] * (1 - alpha);
+				tp[2] = op[2] * alpha + tp[2] * (1 - alpha);
 				tp[3] = op[3] * alpha + tp[3] * (1 - alpha);
 
 				tp += this_bpp;
@@ -506,9 +506,9 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
 			uint8_t* op = other->data()[0] + oy * other->stride()[0];
 			for (int tx = start_tx, ox = start_ox; tx < size().width && ox < other->size().width; ++tx, ++ox) {
 				float const alpha = float (op[3]) / 255;
-				tp[0] = op[0] * alpha + tp[0] * (1 - alpha);
+				tp[0] = op[2] * alpha + tp[0] * (1 - alpha);
 				tp[1] = op[1] * alpha + tp[1] * (1 - alpha);
-				tp[2] = op[2] * alpha + tp[2] * (1 - alpha);
+				tp[2] = op[0] * alpha + tp[2] * (1 - alpha);
 				tp[3] = op[3] * alpha + tp[3] * (1 - alpha);
 
 				tp += this_bpp;
@@ -526,9 +526,9 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
 			for (int tx = start_tx, ox = start_ox; tx < size().width && ox < other->size().width; ++tx, ++ox) {
 				float const alpha = float (op[3]) / 255;
 				/* Blend high bytes */
-				tp[1] = op[0] * alpha + tp[1] * (1 - alpha);
+				tp[1] = op[2] * alpha + tp[1] * (1 - alpha);
 				tp[3] = op[1] * alpha + tp[3] * (1 - alpha);
-				tp[5] = op[2] * alpha + tp[5] * (1 - alpha);
+				tp[5] = op[0] * alpha + tp[5] * (1 - alpha);
 
 				tp += this_bpp;
 				op += other_bpp;