basic speed control for video_loader

1 files changed, 20 insertions, 10 deletions

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 ℑ //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 ℑ //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 ℑ
 	}
     return nullptr;