VideoTexture: reactivate VideoTexture for scons/cmake/makefile compilation systems, fix video streaming, fix camera support in Linux, add multi-thread cache service, fix crash when a VideoFFmpeg object could not be created.

The multi-thread cache service is activated only on multi-core processors.
It consists in loading, decoding and caching the video frames in a 
separate thread. The cache size is 5 decoded frames and 30 raw frames.
Note that the opening of video file/stream/camera is not multi-thread:
you will still experience a delay at the VideoFFmpeg object creation.
Processing of the video frame (resize, loading to texture) is still done
in the main thread.  Caching is automatically enabled for video file, 
video streaming and video camera. 

Video streaming now works correctly: the videos frames are loaded
at the correct rate. Network delays and frequency drifts are automatically
compensated. 
Note: an http video source is always treated as a streaming source,
even though the http protocol allows seeking. For the user it means that
he cannot define start/stop range and cannot restart the video except
by reopening the source. Pause/play is however possible.

Video camera is now correctly handled on Linux: it will not slow down the BGE.
A video camera is treated as a streaming source.

1 files changed, 41 insertions, 5 deletions

diff --git a/source/gameengine/VideoTexture/VideoFFmpeg.h b/source/gameengine/VideoTexture/VideoFFmpeg.h
index e60f1727aab..51ce2c4eebe 100644
--- a/source/gameengine/VideoTexture/VideoFFmpeg.h
+++ b/source/gameengine/VideoTexture/VideoFFmpeg.h
@@ -24,12 +24,17 @@ http://www.gnu.org/copyleft/lesser.txt.
 
 #ifdef WITH_FFMPEG
 extern "C" {
+#include <pthread.h>
 #include <ffmpeg/avformat.h>
 #include <ffmpeg/avcodec.h>
 #include <ffmpeg/rational.h>
 #include <ffmpeg/swscale.h>
+#include "DNA_listBase.h"
+#include "BLI_threads.h"
+#include "BLI_blenlib.h"
 }
 
+
 #if LIBAVFORMAT_VERSION_INT < (49 << 16)
 #define FFMPEG_OLD_FRAME_RATE 1
 #else
@@ -54,6 +59,8 @@ static inline AVCodecContext* get_codec_from_stream(AVStream* stream)
 
 #include "VideoBase.h"
 
+#define CACHE_FRAME_SIZE	5
+#define CACHE_PACKET_SIZE	30
 
 // type VideoFFmpeg declaration
 class VideoFFmpeg : public VideoBase
@@ -91,7 +98,6 @@ public:
 	char *getImageName(void) { return (m_isImage) ? m_imageName.Ptr() : NULL; }
 
 protected:
-
 	// format and codec information
 	AVCodec	*m_codec;
 	AVFormatContext *m_formatCtx;
@@ -138,6 +144,9 @@ protected:
 	/// is file an image?
 	bool m_isImage;
 
+	/// is image loading done in a separate thread?
+	bool m_isThreaded;
+
 	/// keep last image name
 	STR_String m_imageName;
 
@@ -157,10 +166,37 @@ protected:
 	int openStream(const char *filename, AVInputFormat *inputFormat, AVFormatParameters *formatParams);
 
 	/// check if a frame is available and load it in pFrame, return true if a frame could be retrieved
-	bool grabFrame(long frame);
-
-	/// return the frame in RGB24 format, the image data is found in AVFrame.data[0]
-	AVFrame* getFrame(void) { return m_frameRGB; }
+	AVFrame* grabFrame(long frame);
+
+	/// in case of caching, put the frame back in free queue
+	void releaseFrame(AVFrame* frame);
+
+	/// start thread to load the video file/capture/stream 
+	bool startCache();
+	void stopCache();
+
+private:
+	typedef struct {
+		Link link;
+		long framePosition;
+		AVFrame *frame;
+	} CacheFrame;
+	typedef struct {
+		Link link;
+		AVPacket packet;
+	} CachePacket;
+
+	bool m_stopThread;
+	bool m_cacheStarted;
+	ListBase m_thread;
+	ListBase m_frameCacheBase;	// list of frames that are ready
+	ListBase m_frameCacheFree;	// list of frames that are unused
+	ListBase m_packetCacheBase;	// list of packets that are ready for decoding
+	ListBase m_packetCacheFree;	// list of packets that are unused
+	pthread_mutex_t m_cacheMutex;
+
+	AVFrame	*allocFrameRGB();
+	static void *cacheThread(void *);
 };
 
 inline VideoFFmpeg * getFFmpeg (PyImage * self)