Recherche avancée

Sur d’autres sites (8023)

• View UDP stream with lower FPS using JavaCV FFmpegFrameGrabber

  19 décembre 2016, par clic

  I’m using FFmpeg (Windows binary, via command line) with a tee muxer, streaming to UDP with 720p50. No I want my JavaCV application to view the UDP stream with only 30 fps, but it always shows the 50 fps for some reason. For different reasons I’m not using the CanvasFrame, but an ImagePane inside a Swing GUI instead. Relevant code :

      // set up the FFmpegFrameGrabber 
  
      FFmpegFrameGrabber grabber = new FFmpegFrameGrabber("udp://"+ip+":"+port);
  
      grabber.setOption("video_size", "1280x720");
  
      grabber.setFrameRate(30); 
  
      // grabber.setOption("r","30");         // also doesn't work
  
      // grabber.setVideoOption("r","30");    // also doesn't work 
  
      grabber.setVideoCodec(28);              // h264
  
  
  
      // needed to get a BufferedImage out of the Frame
  
      Java2DFrameConverter conv = new Java2DFrameConverter();
  
  
  
      while (!stopplay) {
  
          // grab video frame to IplImage img
  
          img = grabber.grab();    
  
  
  
          // get a BufferedImage from the Frame object
  
          BufferedImage bufImg = conv.getBufferedImage(img);
  
          if(bufImg != null){
  
  
  
              //
  
              // .. some area calculations and scaling here ..
  
              //
  
  
  
              // the BufferedImage is then shown in an ImagePane and repainted
  
  
  
                  imagePane.setImage(bufImg); 
  
  
  
              // ...
  
          }            
  
      }
  
      grabber.stop();

  When I do this with the FFmpeg.exe via command line, I have no problem (streaming the 50fps UDP into a mp4 file with only 30fps using the -r parameter)

  Any ideas ? Thanks !

• Android FFmpeg grab frames in parallel from a video

  7 mai 2016, par Akhil Chandran

  Is there any way to read frames from an mp4 video using JavaCV in parallel ?
  I know that we could grab frames using FFmpegFrameGrabber but is there any other efficient method like using FrameGrabber.Array ?, I tried the below code but its not working.

  frames = new Frame[grabber.getLengthInFrames()];
  
                  frameGrabbers = new FFmpegFrameGrabber[grabber.getLengthInFrames()];
  
                  *//*for (FFmpegFrameGrabber grabber : frameGrabbers) {
  
                      grabber = new FFmpegFrameGrabber(path);
  
                  }*//*
  
                  for (int i = 0; i < grabber.getLengthInFrames(); i++) {
  
                      frameGrabbers[i] = new FFmpegFrameGrabber(path);
  
                  }
  
                  grabberArray = grabber.createArray(frameGrabbers);
  
  
  
                  grabberArray.start();
  
  
  
                  frames = grabberArray.grab();
  
                  grabberArray.release(); 

  The app crashes when I call grabberArray.start().
  Thanks.

• How to stop and save recorded video in ffmpeg using java netbeans ?

  15 juillet 2014, par user3451310

  I found some codes in recording video using webcam but im having a problem in stopping and saving the video output. when i stop it from netbeans, the output video doesn’t show anything(it is like a corrupted video). can anyone tell me what is wrong in this code ? tnx so much for the help

  try {  
  
         OpenCVFrameGrabber grabber = new OpenCVFrameGrabber(0);  
  
         grabber.start();  
  
     opencv_core.IplImage grabbedImage = grabber.grab();  
  
     CanvasFrame canvasFrame = new CanvasFrame("Video recorder");  
  
     canvasFrame.setCanvasSize(grabbedImage.width(), grabbedImage.height());  
  
     grabber.setFrameRate(grabber.getFrameRate());  
  
  
  
     FFmpegFrameRecorder recorder = new FFmpegFrameRecorder("D:/Vid/testvideo.mp4", grabber.getImageWidth(), grabber.getImageHeight());
  
     recorder.setFormat("mp4");  
  
     recorder.setFrameRate(30);  
  
     recorder.setVideoBitrate(10 * 1024 * 1024); 
  
     recorder.setVideoCodec(13);
  
  
  
  
  
     recorder.start();  
  
     while (canvasFrame.isVisible() && (grabbedImage = grabber.grab()) != null) {  
  
       canvasFrame.showImage(grabbedImage);  
  
       recorder.record(grabbedImage);  
  
     }  
  
     recorder.stop();  
  
     grabber.stop();  
  
     canvasFrame.dispose();  
  
  
  
   } catch (FrameGrabber.Exception ex) {  
  
     Logger.getLogger(web.class.getName()).log(Level.SEVERE, null, ex);  
  
   } catch (FrameRecorder.Exception ex) {  
  
     Logger.getLogger(web.class.getName()).log(Level.SEVERE, null, ex);  
  
   }  
  
  
  
  
  
  }