Fix GIFs with alpha display.

Telegram/SourceFiles/media/streaming/media_streaming_utility.cpp

@@ -212,6 +212,7 @@ void PaintFrameInner(
 		QPainter &p,
 		QRect to,
 		const QImage &original,
+		bool alpha,
 		int rotation) {
 	const auto rotated = [](QRect rect, int rotation) {
 		switch (rotation) {
@@ -239,22 +240,32 @@ void PaintFrameInner(
 	if (rotation) {
 		p.rotate(rotation);
 	}
-	p.drawImage(rotated(to, rotation), original);
+	const auto rect = rotated(to, rotation);
+	if (alpha) {
+		p.fillRect(rect, Qt::white);
+	}
+	p.drawImage(rect, original);
 }
 
 void PaintFrameContent(
 		QPainter &p,
 		const QImage &original,
+		bool alpha,
 		int rotation,
 		const FrameRequest &request) {
-	const auto full = request.outer;
+	const auto full = request.outer.isEmpty()
+		? original.size()
+		: request.outer;
+	const auto size = request.resize.isEmpty()
+		? original.size()
+		: request.resize;
 	const auto to = QRect(
-		(full.width() - request.resize.width()) / 2,
-		(full.height() - request.resize.height()) / 2,
-		request.resize.width(),
-		request.resize.height());
+		(full.width() - size.width()) / 2,
+		(full.height() - size.height()) / 2,
+		size.width(),
+		size.height());
 	PaintFrameOuter(p, to, full);
-	PaintFrameInner(p, to, original, rotation);
+	PaintFrameInner(p, to, original, alpha, rotation);
 }
 
 void ApplyFrameRounding(QImage &storage, const FrameRequest &request) {
@@ -267,17 +278,21 @@ void ApplyFrameRounding(QImage &storage, const FrameRequest &request) {
 
 QImage PrepareByRequest(
 		const QImage &original,
+		bool alpha,
 		int rotation,
 		const FrameRequest &request,
 		QImage storage) {
-	Expects(!request.outer.isEmpty());
+	Expects(!request.outer.isEmpty() || alpha);
 
-	if (!FFmpeg::GoodStorageForFrame(storage, request.outer)) {
-		storage = FFmpeg::CreateFrameStorage(request.outer);
+	const auto outer = request.outer.isEmpty()
+		? original.size()
+		: request.outer;
+	if (!FFmpeg::GoodStorageForFrame(storage, outer)) {
+		storage = FFmpeg::CreateFrameStorage(outer);
 	}
 
 	QPainter p(&storage);
-	PaintFrameContent(p, original, rotation, request);
+	PaintFrameContent(p, original, alpha, rotation, request);
 	p.end();
 
 	ApplyFrameRounding(storage, request);

Telegram/SourceFiles/media/streaming/media_streaming_utility.h

@@ -60,6 +60,7 @@ struct Stream {
 	QImage storage);
 [[nodiscard]] QImage PrepareByRequest(
 	const QImage &original,
+	bool alpha,
 	int rotation,
 	const FrameRequest &request,
 	QImage storage);

Telegram/SourceFiles/media/streaming/media_streaming_video_track.cpp

@@ -361,6 +361,7 @@ void VideoTrackObject::presentFrameIfNeeded() {
 		Expects(frame->position != kFinishedPosition);
 
 		fillRequests(frame);
+		frame->alpha = (frame->decoded->format == AV_PIX_FMT_BGRA);
 		frame->original = ConvertFrame(
 			_stream,
 			frame->decoded.get(),
@@ -982,7 +983,8 @@ QImage VideoTrack::frame(
 			unwrapped.updateFrameRequest(instance, useRequest);
 		});
 	}
-	if (GoodForRequest(frame->original, _streamRotation, useRequest)) {
+	if (!frame->alpha
+		&& GoodForRequest(frame->original, _streamRotation, useRequest)) {
 		return frame->original;
 	} else if (changed || none || i->second.image.isNull()) {
 		const auto j = none
@@ -1002,6 +1004,7 @@ QImage VideoTrack::frame(
 		}
 		j->second.image = PrepareByRequest(
 			frame->original,
+			frame->alpha,
 			_streamRotation,
 			useRequest,
 			std::move(j->second.image));
@@ -1025,7 +1028,8 @@ void VideoTrack::PrepareFrameByRequests(
 	const auto end = frame->prepared.end();
 	for (auto i = begin; i != end; ++i) {
 		auto &prepared = i->second;
-		if (!GoodForRequest(frame->original, rotation, prepared.request)) {
+		if (frame->alpha
+			|| !GoodForRequest(frame->original, rotation, prepared.request)) {
 			auto j = begin;
 			for (; j != i; ++j) {
 				if (j->second.request == prepared.request) {
@@ -1036,6 +1040,7 @@ void VideoTrack::PrepareFrameByRequests(
 			if (j == i) {
 				prepared.image = PrepareByRequest(
 					frame->original,
+					frame->alpha,
 					rotation,
 					prepared.request,
 					std::move(prepared.image));

Telegram/SourceFiles/media/streaming/media_streaming_video_track.h

@@ -83,6 +83,8 @@ private:
 		crl::time display = kTimeUnknown;
 
 		base::flat_map<const Instance*, Prepared> prepared;
+
+		bool alpha = false;
 	};
 
 	class Shared {

Telegram/SourceFiles/media/view/media_view_pip.cpp

@@ -1391,6 +1391,7 @@ QImage Pip::videoFrame(const FrameRequest &request) const {
 		if (state == ThumbState::Cover) {
 			_preparedCoverStorage = Streaming::PrepareByRequest(
 				_instance.info().video.cover,
+				false,
 				_instance.info().video.rotation,
 				request,
 				std::move(_preparedCoverStorage));