Pass around shared_ptrs to newly allocated AegiVideoFrames rather than pointers into a buffer of AegiVideoFrames in ThreadedFrameSource

Originally committed to SVN as r4789.

aegisub/src/threaded_frame_source.cpp

@@ -58,12 +58,15 @@ struct invisible_line : public std::unary_function<const AssEntry*, bool> {
 	}
 };
 
-AegiVideoFrame const& ThreadedFrameSource::ProcFrame(int frameNum, double time, bool raw) {
-	AegiVideoFrame *frame;
+static void delete_frame(AegiVideoFrame *frame) {
+	frame->Clear();
+	delete frame;
+}
+
+std::tr1::shared_ptr<AegiVideoFrame> ThreadedFrameSource::ProcFrame(int frameNum, double time, bool raw) {
+	std::tr1::shared_ptr<AegiVideoFrame> frame(new AegiVideoFrame, delete_frame);
 	{
 		wxMutexLocker locker(providerMutex);
-		frame = frameBuffer + frameBufferIdx;
-		frameBufferIdx = !frameBufferIdx;
 		try {
 			frame->CopyFrom(videoProvider->GetFrame(frameNum));
 		}
@@ -110,7 +113,7 @@ AegiVideoFrame const& ThreadedFrameSource::ProcFrame(int frameNum, double time,
 
 		provider->DrawSubtitles(*frame, time);
 	}
-	return *frame;
+	return frame;
 }
 
 void *ThreadedFrameSource::Entry() {
@@ -137,10 +140,7 @@ void *ThreadedFrameSource::Entry() {
 		}
 
 		try {
-			AegiVideoFrame const& frame = ProcFrame(frameNum, time);
-
-			std::tr1::shared_ptr<wxMutexLocker> evtLock(new wxMutexLocker(evtMutex));
-			FrameReadyEvent *evt = new FrameReadyEvent(&frame, time, evtLock);
+			FrameReadyEvent *evt = new FrameReadyEvent(ProcFrame(frameNum, time), time);
 			evt->SetEventType(EVT_FRAME_READY);
 			parent->QueueEvent(evt);
 		}
@@ -160,7 +160,6 @@ ThreadedFrameSource::ThreadedFrameSource(wxString videoFileName, wxEvtHandler *p
 , parent(parent)
 , nextTime(-1.)
 , jobReady(jobMutex)
-, frameBufferIdx(0)
 , run(true)
 {
 	Create();
@@ -170,8 +169,6 @@ ThreadedFrameSource::~ThreadedFrameSource() {
 	run = false;
 	jobReady.Signal();
 	Wait();
-	frameBuffer[0].Clear();
-	frameBuffer[1].Clear();
 }
 
 void ThreadedFrameSource::LoadSubtitles(AssFile *subs) throw() {
@@ -192,7 +189,7 @@ void ThreadedFrameSource::RequestFrame(int frame, double time) throw() {
 	jobReady.Signal();
 }
 
-AegiVideoFrame const& ThreadedFrameSource::GetFrame(int frame, double time, bool raw) {
+std::tr1::shared_ptr<AegiVideoFrame> ThreadedFrameSource::GetFrame(int frame, double time, bool raw) {
 	return ProcFrame(frame, time, raw);
 }
 

aegisub/src/threaded_frame_source.h

@@ -76,17 +76,10 @@ class ThreadedFrameSource : public wxThread {
 
 	wxCondition jobReady;  ///< Signal for indicating that a frame has be requested
 
-	/// Frame buffers to render subtitles into
-	/// Two are needed so that a frame can be decoded/rendered while the GUI is
-	/// doing stuff with the other
-	AegiVideoFrame frameBuffer[2];
-	/// Next frame buffer to use
-	int frameBufferIdx;
-
 	bool run; ///< Should the thread continue to run
 
 	void *Entry();
-	AegiVideoFrame const& ProcFrame(int frameNum, double time, bool raw = false);
+	std::tr1::shared_ptr<AegiVideoFrame> ProcFrame(int frameNum, double time, bool raw = false);
 public:
 	/// @brief Load the passed subtitle file
 	/// @param subs File to load
@@ -107,7 +100,7 @@ public:
 	/// @brief frame Frame number
 	/// @brief time  Exact start time of the frame in seconds
 	/// @brief raw   Get raw frame without subtitles
-	AegiVideoFrame const& GetFrame(int frame, double time, bool raw = false);
+	std::tr1::shared_ptr<AegiVideoFrame> GetFrame(int frame, double time, bool raw = false);
 
 	std::tr1::shared_ptr<VideoProvider> GetVideoProvider() const { return videoProvider; }
 
@@ -121,24 +114,14 @@ public:
 /// @class FrameReadyEvent
 /// @brief Event which signals that a requested frame is ready
 class FrameReadyEvent : public wxEvent {
-	/// Externally passed mutex that is kept locked as long as this or a copy
-	/// of this exists. Used to ensure that the next FrameReadyEvent is not
-	/// announced until this one is fully processed.
-	///
-	/// Although tr1 does not require that shared_ptr be thread safe (due to
-	/// the standard having no concept of threads), all implementations have
-	/// at least a thread safe reference counter, which is all we happen to
-	/// need here.
-	std::tr1::shared_ptr<wxMutexLocker> mutex;
 public:
-	/// Frame which is ready; only guaranteed to be valid as long as this
-	/// event object exists
-	const AegiVideoFrame *frame;
+	/// Frame which is ready
+	std::tr1::shared_ptr<AegiVideoFrame> frame;
 	/// Time which was used for subtitle rendering
 	double time;
 	wxEvent *Clone() const { return new FrameReadyEvent(*this); };
-	FrameReadyEvent(const AegiVideoFrame *frame, double time, std::tr1::shared_ptr<wxMutexLocker> mutex)
-		: mutex(mutex), frame(frame), time(time) {
+	FrameReadyEvent(std::tr1::shared_ptr<AegiVideoFrame> frame, double time)
+		: frame(frame), time(time) {
 	}
 };
 

aegisub/src/video_context.cpp

@@ -295,7 +295,7 @@ void VideoContext::GetFrameAsync(int n) {
 	provider->RequestFrame(n,videoFPS.TimeAtFrame(n)/1000.0);
 }
 
-AegiVideoFrame const& VideoContext::GetFrame(int n, bool raw) {
+std::tr1::shared_ptr<AegiVideoFrame> VideoContext::GetFrame(int n, bool raw) {
 	return provider->GetFrame(n, videoFPS.TimeAtFrame(n)/1000.0, raw);
 }
 
@@ -341,7 +341,7 @@ void VideoContext::SaveSnapshot(bool raw) {
 		if (!tryPath.FileExists()) break;
 	}
 
-	GetFrame(frame_n,raw).GetImage().SaveFile(path,wxBITMAP_TYPE_PNG);
+	GetFrame(frame_n,raw)->GetImage().SaveFile(path,wxBITMAP_TYPE_PNG);
 }
 
 void VideoContext::GetScriptSize(int &sw,int &sh) {

aegisub/src/video_context.h

@@ -172,7 +172,7 @@ public:
 
 	/// @brief Get the video provider used for the currently open video
 	VideoProvider *GetProvider() const { return videoProvider.get(); }
-	AegiVideoFrame const& GetFrame(int n, bool raw = false);
+	std::tr1::shared_ptr<AegiVideoFrame> GetFrame(int n, bool raw = false);
 	void GetFrameAsync(int n);
 
 	/// @brief Save the currently displayed frame as an image

aegisub/src/video_display.cpp

@@ -592,14 +592,14 @@ void VideoDisplay::FromScriptCoords(int *x, int *y) const {
 
 void VideoDisplay::OnCopyToClipboard(wxCommandEvent &) {
 	if (wxTheClipboard->Open()) {
-		wxTheClipboard->SetData(new wxBitmapDataObject(wxBitmap(VideoContext::Get()->GetFrame(currentFrame).GetImage(),24)));
+		wxTheClipboard->SetData(new wxBitmapDataObject(wxBitmap(VideoContext::Get()->GetFrame(currentFrame)->GetImage(),24)));
 		wxTheClipboard->Close();
 	}
 }
 
 void VideoDisplay::OnCopyToClipboardRaw(wxCommandEvent &) {
 	if (wxTheClipboard->Open()) {
-		wxTheClipboard->SetData(new wxBitmapDataObject(wxBitmap(VideoContext::Get()->GetFrame(currentFrame,true).GetImage(),24)));
+		wxTheClipboard->SetData(new wxBitmapDataObject(wxBitmap(VideoContext::Get()->GetFrame(currentFrame,true)->GetImage(),24)));
 		wxTheClipboard->Close();
 	}
 }