split out RunDecode function

stepmania/src/arch/MovieTexture/MovieTexture_FFMpeg.cpp

@@ -420,6 +420,8 @@ try {
 	m_ImageWaiting = false;
 	m_Rate = 1;
 	m_bWantRewind = false;
+	m_Clock = 0;
+	m_FrameSkipMode = false;
 
 	m_BufferFinished = SDL_CreateSemaphore(0);
 
@@ -711,49 +713,28 @@ void MovieTexture_FFMpeg::CreateTexture()
     m_uTexHandle = DISPLAY->CreateTexture( pixfmt, m_img, false );
 }
 
-
-
-void MovieTexture_FFMpeg::DecoderThread()
-{
-	RageTimer Timer;
-	float Clock = 0;
-	bool FrameSkipMode = false;
-
-#if defined(_WINDOWS)
-	/* Movie decoding is bursty.  We burst decode a frame, then we sleep, then we burst
-	 * to YUV->RGB convert, then we wait for the frame to move, and we repeat.  */
-//	if(!SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_BELOW_NORMAL))
-//		LOG->Warn(werr_ssprintf(GetLastError(), "Failed to set sound thread priority"));
-
-	/* Windows likes to boost priority when processes come out of a wait state.  We don't
-	 * want that, since it'll result in us having a small priority boost after each movie
-	 * frame, resulting in skips in the gameplay thread. */
-	if( !SetThreadPriorityBoost(GetCurrentThread(), TRUE) && GetLastError() != ERROR_NOT_SUPPORTED )
-		LOG->Warn( werr_ssprintf(GetLastError(), "SetThreadPriorityBoost failed") );
-#endif
-
-	CHECKPOINT;
-
-	while( m_State != DECODER_QUIT )
+/* Handle decoding for a frame.  Return true if a frame was decoded and is waiting
+ * to be handled. */
+bool MovieTexture_FFMpeg::RunDecode()
 {
 	if( m_State == PAUSE_DECODER )
 	{
-			SDL_Delay( 10 );
-			
 		/* The video isn't running; skip time. */
-			Timer.GetDeltaTime();
-			continue;
+		m_Timer.GetDeltaTime();
+		return false;
 	}
 
+	if( m_State != PLAYING )
+		return false;
 	CHECKPOINT;
 
 	/* We're playing.  Update the clock. */
-		Clock += Timer.GetDeltaTime() * m_Rate;
+	m_Clock += m_Timer.GetDeltaTime() * m_Rate;
 	
 	/* Read a frame. */
 	int ret = decoder->GetFrame();
 	if( ret == -1 )
-			return;
+		return false;
 
 	if( m_bWantRewind && decoder->GetTimestamp() == 0 )
 		m_bWantRewind = false; /* ignore */
@@ -762,7 +743,7 @@ void MovieTexture_FFMpeg::DecoderThread()
 	{
 		/* EOF. */
 		if( !m_bLoop )
-				return;
+			return false;
 
 		LOG->Trace( "File \"%s\" looping", GetID().filename.c_str() );
 		m_bWantRewind = true;
@@ -777,22 +758,22 @@ void MovieTexture_FFMpeg::DecoderThread()
 		CreateDecoder();
 
 		decoder->Init();
-			Clock = 0;
-			continue;
+		m_Clock = 0;
+		return false;
 	}
 
 	/* We got a frame. */
-		const float Offset = decoder->GetTimestamp() - Clock;
+	const float Offset = decoder->GetTimestamp() - m_Clock;
 
 	/* If we're ahead, we're decoding too fast; delay. */
 	if( Offset > 0 )
 	{
 		SDL_Delay( int(1000*Offset) );
-			if( FrameSkipMode )
+		if( m_FrameSkipMode )
 		{
 			/* We're caught up; stop skipping frames. */
 			LOG->Trace( "stopped skipping frames" );
-				FrameSkipMode = false;
+			m_FrameSkipMode = false;
 		}
 	} else {
 		/* We're behind by -Offset seconds.  
@@ -822,16 +803,16 @@ void MovieTexture_FFMpeg::DecoderThread()
 		 */
 		const float FrameSkipThreshold = 0.5f;
 
-			if( -Offset >= FrameSkipThreshold && !FrameSkipMode )
+		if( -Offset >= FrameSkipThreshold && !m_FrameSkipMode )
 		{
 			LOG->Trace( "(%s) Time is %f, and the movie is at %f.  Entering frame skip mode.",
-					GetID().filename.c_str(), Clock, decoder->GetTimestamp());
-				FrameSkipMode = true;
+				GetID().filename.c_str(), m_Clock, decoder->GetTimestamp());
+			m_FrameSkipMode = true;
 		}
 	}
 
-		if( FrameSkipMode && decoder->m_stream->codec.frame_number % 2 )
-			continue; /* skip */
+	if( m_FrameSkipMode && decoder->m_stream->codec.frame_number % 2 )
+		return false; /* skip */
 	
 	/* Convert it. */
 	ConvertFrame();
@@ -839,7 +820,42 @@ void MovieTexture_FFMpeg::DecoderThread()
 	/* Signal the main thread to update the image on the next Update. */
 	m_ImageWaiting=true;
 
+	return true;
+}
+
+void MovieTexture_FFMpeg::DecoderThread()
+{
+#if defined(_WINDOWS)
+	/* Movie decoding is bursty.  We burst decode a frame, then we sleep, then we burst
+	 * to YUV->RGB convert, then we wait for the frame to move, and we repeat.  */
+//	if(!SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_BELOW_NORMAL))
+//		LOG->Warn(werr_ssprintf(GetLastError(), "Failed to set sound thread priority"));
+
+	/* Windows likes to boost priority when processes come out of a wait state.  We don't
+	 * want that, since it'll result in us having a small priority boost after each movie
+	 * frame, resulting in skips in the gameplay thread. */
+	if( !SetThreadPriorityBoost(GetCurrentThread(), TRUE) && GetLastError() != ERROR_NOT_SUPPORTED )
+		LOG->Warn( werr_ssprintf(GetLastError(), "SetThreadPriorityBoost failed") );
+#endif
+
+	CHECKPOINT;
+
+	while( m_State != DECODER_QUIT )
+	{
+		bool bGotFrame = RunDecode();
+
+		if( m_State == PAUSE_DECODER )
+		{
+			/* We aren't feeding frames, so we aren't waiting; don't chew CPU. */
+			SDL_Delay( 10 );
+			continue;
+		}
+
+		if( !bGotFrame )
+			continue;
+
 		/* SDL_SemWait does not properly retry sem_wait in Linux on EINTR. */
+		int ret;
 		do
 		{
 			CHECKPOINT;

stepmania/src/arch/MovieTexture/MovieTexture_FFMpeg.h

@@ -6,6 +6,7 @@
 #include "RageDisplay.h"
 #include "RageTexture.h"
 #include "RageThreads.h"
+#include "RageTimer.h"
 
 #include "SDL_mutex.h"
 
@@ -64,6 +65,10 @@ private:
 
 	SDL_sem *m_BufferFinished;
 
+	RageTimer m_Timer;
+	float m_Clock;
+	bool m_FrameSkipMode;
+
 	static int DecoderThread_start(void *p) { ((MovieTexture_FFMpeg *)(p))->DecoderThread(); return 0; }
 	void DecoderThread();
 	RageThread m_DecoderThread;
@@ -77,6 +82,7 @@ private:
 	void DestroyTexture();
 	void StartThread();
 	void StopThread();
+	bool RunDecode();
 };
 
 /*