basic speed control for video_loader

4 files changed, 47 insertions, 12 deletions

diff --git a/rotord/src/libavwrapper.cpp b/rotord/src/libavwrapper.cpp
index 7c00b91..c21d077 100755
--- a/rotord/src/libavwrapper.cpp
+++ b/rotord/src/libavwrapper.cpp
@@ -223,6 +223,10 @@ bool libav::decoder::openUsingInitializedContainer(enum PixelFormat formatParam)
     if( pCtx->time_base.num > 1000 && pCtx->time_base.den == 1 )
         pCtx->time_base.den = 1000;
 
+    framerate=(((float)container->streams[videoStream]->r_frame_rate.num)/((float)container->streams[videoStream]->r_frame_rate.den));
+
+    //cerr<<"codecContext timebase: "<<(((float)pCtx->time_base.num)/((float)pCtx->time_base.den))<<" videostream framerate: "<<(((float)container->streams[videoStream]->r_frame_rate.num)/((float)container->streams[videoStream]->r_frame_rate.den))<<endl;
+
     //cerr<<"stream frame rate:"<<container->streams[videoStream]->r_frame_rate.num<<"/"<<container->streams[videoStream]->r_frame_rate.den<<endl;
 
     //cerr<<"video duration: "<<container->duration<<endl;
@@ -240,8 +244,7 @@ bool libav::decoder::openUsingInitializedContainer(enum PixelFormat formatParam)
 
     if (numFrames<1){
         //some codecs don't keep this info in the header
-         float fr=((float)container->streams[videoStream]->r_frame_rate.num)/container->streams[videoStream]->r_frame_rate.den;
-        numFrames = (int)(( container->duration / (double)AV_TIME_BASE ) * fr );
+        numFrames = (int)(( container->duration / (double)AV_TIME_BASE ) * framerate );
         //this approach still doesn't seem to give quite the right answer- comes out a little too big
         //could alternatively just redefine the length if the reader fails
     }
diff --git a/rotord/src/libavwrapper.h b/rotord/src/libavwrapper.h
index 4c5cb02..ebe47c1 100755
--- a/rotord/src/libavwrapper.h
+++ b/rotord/src/libavwrapper.h
@@ -29,6 +29,10 @@
 //http://blog.tomaka17.com/2012/03/libavcodeclibavformat-tutorial/
 //great to use c++11 features
 
+
+//http://dranger.com/ffmpeg/
+//the mnost up to date tutorial?
+
 #ifndef UINT64_C
 #define UINT64_C(c) (c ## ULL)
 #endif
@@ -103,6 +107,7 @@ namespace libav {
         int getNumberOfFrames() const;
         int getWidth() const;
         int getHeight() const;
+        float getFrameRate() const{return framerate;};
         int getNumberOfChannels() const;
         bool readNextFrame(int targetFrameIndex = 0);
         bool readNextFrameWithPacket(int targetFrameIndex, AVPacket& packet, AVFrame* pYuv);
@@ -116,6 +121,7 @@ namespace libav {
         int videoStream;
         int previousFrameIndex;
         bool isOpen;
+        
 
         bool open(std::string& fileName, enum PixelFormat formatParam = PIX_FMT_RGB24);
         bool open(char* fileName, enum PixelFormat formatParam = PIX_FMT_RGB24);
@@ -138,6 +144,9 @@ namespace libav {
         size_t numBytes;
         int numFrames;
         int sc; // number of color channels
+        float framerate; 
+        //NB representing framerate as a float implies that 
+        //ABOVE ~93 HOURS AT 25FPS the calculations will be inaccurate
 
     };
 
diff --git a/rotord/src/rotor.cpp b/rotord/src/rotor.cpp
index f96fbc3..c7e7bc7 100755
--- a/rotord/src/rotor.cpp
+++ b/rotord/src/rotor.cpp
@@ -282,7 +282,7 @@ bool Video_loader::load(const string &_filename){
 	string uri="file://"+_filename;
     isLoaded=player.open(uri);
 	if (isLoaded){
-		logger.information("Video_loader loaded "+filename+": "+ofToString(player.getNumberOfFrames())+" frames, "+ofToString(player.getWidth())+"x"+ofToString(player.getHeight()));
+		logger.information("Video_loader loaded "+filename+": "+ofToString(player.getNumberOfFrames())+" frames, "+ofToString(player.getFrameRate())+" fps, "+ofToString(player.getWidth())+"x"+ofToString(player.getHeight()));
 		return true;
    	}
    	
@@ -293,16 +293,26 @@ bool Video_loader::load(const string &_filename){
 Image* Video_loader::output(const Frame_spec &frame){
 
 	if (isLoaded){
-		int wanted=(((int) ((frame.time*frame.framerate)+0.5))%(player.getNumberOfFrames()-1))+1;  //+1 is necessary because 1st frame in a video is number 1?
+		//this approach is running into the inability to seek when requesting playback speed > 1. 
+		//need to cache frames so as to avoid asking for a frame other than the next one.
+		//need an algorithm to find the previous keyframe and seek forward
 
-		if (!player.fetchFrame(frame.w,frame.h,wanted)) { //seek fail
-			Logger& logger = Logger::get("Rotor");
-			logger.error("Video_loader failed to seek frame "+ofToString(wanted)+" of "+filename);
-		
-			if (image.w>0) return &image; //just return the previous frame if possible
-			else return nullptr;
-		 };
-		image.setup_fromRGB(frame.w,frame.h,player.pFrameRGB->data[0],player.pFrameRGB->linesize[0]-(frame.w*3));
+		float clipframerate=(framerate==0.0f?player.getFrameRate():framerate);
+
+		float clipspeed=(clipframerate/frame.framerate)*speed;
+
+		int wanted=(((int) ((frame.time*frame.framerate*clipspeed)+0.5))%(player.getNumberOfFrames()-1))+1;  //+1 is necessary because 1st frame in a video is number 1?
+		if (wanted!=lastframe){
+			if (!player.fetchFrame(frame.w,frame.h,wanted)) { //seek fail
+				Logger& logger = Logger::get("Rotor");
+				logger.error("Video_loader failed to seek frame "+ofToString(wanted)+" of "+filename);
+			
+				if (image.w>0) return &image; //just return the previous frame if possible
+				else return nullptr;
+			}
+			image.setup_fromRGB(frame.w,frame.h,player.pFrameRGB->data[0],player.pFrameRGB->linesize[0]-(frame.w*3));
+			lastframe=wanted;
+		}
 		return &image;
 	}
     return nullptr;
diff --git a/rotord/src/rotor.h b/rotord/src/rotor.h
index 85e7ac4..8e37b51 100755
--- a/rotord/src/rotor.h
+++ b/rotord/src/rotor.h
@@ -1037,6 +1037,8 @@ namespace Rotor {
 		private:
 			Image *image; //is an image generator
 	};
+#define VIDEOFRAMES_still 1
+#define VIDEOFRAMES_blend 2
 	class Video_loader: public Image_node {
 		public:
 			Video_loader(){};
@@ -1044,9 +1046,16 @@ namespace Rotor {
 				base_settings(settings);
 				isLoaded=false;
 				filename=find_setting(settings,"filename","");
+				speed=find_setting(settings,"speed",1.0f);
+				framerate=find_setting(settings,"framerate",0.0f);
+				//0.0f signifies to use the internal framerate
 				if (filename!="") {
 					load(find_setting(settings,"media_path","")+filename);
 				}
+				string frame_op=find_setting(settings,"mode","still");
+				if (frame_op=="still") mode=VIDEOFRAMES_still;
+				if (frame_op=="blend") mode=VIDEOFRAMES_blend;
+				lastframe=0;
 			};
 			~Video_loader(){};
 			bool load(const string &filename);
@@ -1057,6 +1066,10 @@ namespace Rotor {
 			libav::decoder player;
 			Image image;
 			string filename;
+			float speed;
+			float framerate;
+			int mode;
+			int lastframe;
 	};
 	/*
 	class CVideo_loader: public Image_node {