Add DecodeNextFrame and DecodeMovie functions to populate the

FrameBuffer.

src/arch/MovieTexture/MovieTexture_FFMpeg.cpp

@@ -10,6 +10,7 @@
 #include <cerrno>
 #include <cstddef>
 #include <cstdint>
+#include <thread>
 
 static void FixLilEndian()
 {
@@ -213,11 +214,71 @@ float MovieDecoder_FFMpeg::GetTimestamp() const
 	return m_fTimestamp - m_fTimestampOffset;
 }
 
+bool MovieDecoder_FFMpeg::IsCurrentFrameReady() {
+	std::lock_guard<std::mutex>(m_FrameBuffer[m_iFrameNumber].lock);
+	if (!m_FrameBuffer[m_iFrameNumber].decoded) {
+		LOG->Info("Frame %i not decoded, total frames: %i", m_iFrameNumber, m_totalFrames);
+	}
+	return m_FrameBuffer[m_iFrameNumber].decoded;
+}
+
 float MovieDecoder_FFMpeg::GetFrameDuration() const
 {
 	return m_fLastFrameDelay;
 }
 
+int MovieDecoder_FFMpeg::DecodeNextFrame()
+{
+	// Add in a new FrameBuffer entry, and lock it immediately.
+	m_FrameBuffer.push_back(FrameHolder());
+	std::lock_guard<std::mutex>(m_FrameBuffer.back().lock);
+	int status = SendPacketToBuffer();
+	if (status < 0) {
+		return status;
+	}
+	status = DecodePacketInBuffer();
+	if (firstFrame) {
+		firstFrame = false;
+	}
+	return status;
+}
+
+int MovieDecoder_FFMpeg::DecodeMovie()
+{
+	using std::chrono::operator""ms;
+
+	// The first frame expected to be decoded and drawn already,
+	// that is handled by MovieTexture_Generic::Init().
+	int frameNum = 0;
+	while (!m_iEOF) {
+		// This wake up time could be tied to the RageTimer, but as it doesn't
+		// need to sync with other parts of ITGm, using chrono is fine.
+		// The 1ms time here is arbitrary, and means that the game will decode
+		// at a maximum speed of 1 frame per ms (or 1000 fps).
+		auto wake_up = std::chrono::steady_clock::now() + 1ms;
+
+		int status = DecodeNextFrame();
+
+		// If cancelled (quitting a song, scrolling the banner), or fatal error,
+		// stop decoding.
+		if (status < 0) {
+			return status;
+		}
+
+		frameNum++;
+
+		// This means when opening the file, less frames were detected than
+		// there actually are. Increment to keep up so we don't end the video
+		// early during display.
+		if (frameNum - 1 > m_totalFrames) {
+			m_totalFrames++;
+		}
+
+		std::this_thread::sleep_until(wake_up);
+	}
+	return 0;
+}
+
 int MovieDecoder_FFMpeg::SendPacketToBuffer()
 {
 	if (cancel) {

src/arch/MovieTexture/MovieTexture_FFMpeg.h

@@ -73,6 +73,23 @@ public:
 	void GetFrame( RageSurface *pOut );
 	int DecodeFrame( float fTargetTime );
 
+	// Decode a single frame.  Return -2 on cancel, -1 on error, 0 on EOF, 1 if we have a frame.
+	int DecodeNextFrame();
+
+	// Decode the entire movie.
+	// If we let this decode as fast as possible, it could come at the expense
+	// of gameplay performance. Since dropping frames is undesirable, an
+	// artificial rate limit is introduced.
+	//
+	// Given that most movies will display at 30fps or 60fps, decoding at a
+	// speed of 1000fps should be more than sufficient to ensure we never
+	// run behind. This rate limiting is only needed in case itgmania is
+	// running on a low performance machine, or the movie is REALLY long.
+	//
+	// Returns 0 on success, -1 on fatal error, -2 on cancel.
+	int DecodeMovie();
+	bool IsCurrentFrameReady();
+
 	int GetWidth() const { return m_pStreamCodec->width; }
 	int GetHeight() const { return m_pStreamCodec->height; }
 

src/arch/MovieTexture/MovieTexture_Generic.h

@@ -28,6 +28,14 @@ public:
 	virtual void Close() = 0;
 	virtual void Rewind() = 0;
 
+	// Decode the next frame.
+	// Return 1 on success, 0 on EOF, -1 on fatal error, -2 on cancel.
+	virtual int DecodeNextFrame() = 0;
+	virtual int DecodeMovie() = 0;
+
+	// Returns true if the frame we want to display has been decoded already.
+	virtual bool IsCurrentFrameReady() = 0;
+
 	/*
 	 * Decode a frame.  Return 1 on success, 0 on EOF, -1 on fatal error.
 	 *
@@ -95,6 +103,10 @@ public:
 	virtual void Reload();
 
 	virtual void SetPosition( float fSeconds );
+
+	// UpdateMovie tells the MovieTexture to update the displayed frame based
+	// on fSeconds passed in. (e.g., 5.9 input means show the frame that should
+	// be displayed 5.9 seconds into the movie).
 	virtual void UpdateMovie( float fSeconds );
 	virtual void SetPlaybackRate( float fRate ) { m_fRate = fRate; }
 	void SetLooping( bool bLooping=true ) { m_bLoop = bLooping; }