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• How to work with data from streaming services in my Java application ?

  24 novembre 2020, par gabriel garcia

  I'm currently trying to develop an "streaming client" as a way to organize multiple stream services (twitch, yt, mitele...) in a single desktop application written in Java.

  


  It basically relies on streamlink (which relies in ffmpeg) thanks to all it's features so my project could be defined as a frontend for streamlink.

  


  Straight to the point, one of the features I'd like to add it is the option to programatically record streams in the background and showing this video stream to the user when it's requested. Since there's also the possibility that the user wants to watch the stream without recording it, I'm forced to work with all that byte-like data sent from those streaming sources.

  


  So, the problem is basically that I do not know much about video coding/decoding/muxing/demuxing nor video theory like container structure, video formats and such.

  


  But the idea is to work with all the data sent from the stream source (let's say twitch, for example), read this bytes (I'm not sure what kind of information is sent to the client nor format) from the java.lang.Process's stdout and then present it to the client.

  


  Here's another problem : I don't know how to play video streams in JavaFX and I don't think it's even supported right now. So I would have to extract each frame and sound associated from the stdout and show them to the user each time a new frame is received (oups, another problem since I don't know when does each frame starts/ends since I'm reading each stdout's line).

  


  As a summary :

  


  

  • How can I know when does each frame starts/stops ?

  


  • How can I extract the image and sound from each frame ?

  


  


  I hope I'm not asking too much and that you could shed some light upon my darkness.

  


• using ffmpeg.exe and java to get images from video

  28 juin 2013, par user2190639

  I'm trying to make a java function that given in input a video it generates a sets of images by seconds, so far this is what I've got :

  public static void decodeAndCaptureFrames(String inputfilename, String outputfolder, int width, int height, double seconds) throws InputFormatException, EncoderException
  
  double duration = getVideoLenght(inputfilename) ;
  int index = 0 ;

      Runtime runtime = Runtime.getRuntime();
  
      for(double s = 0; s < duration; s+= seconds)
  
      {
  
          String outString = outputfolder + File.separator + index + ".png";
  
          String cmd = "ffmpeg.exe -i "+ inputfilename +" -f image2 -t 0.001 -ss "+ s +" -s "+ width +"x"+ height +" "+outString;
  
  
  
          try {
  
              Process p = runtime.exec(cmd);
  
              p.waitFor()
  
          } catch (IOException e) {
  
              System.out.println("problema nell'esecuzione del runtime.exec");
  
              e.printStackTrace();
  
          } catch (InterruptedException e) {
  
              // TODO Auto-generated catch block
  
              e.printStackTrace();
  
          }
  
  
  
          System.out.println(cmd);
  
          index++;
  
      }   
  
  }

  However the code is really slow and it only converts the first two images even if I get the print of the further images.
  Since I'm using this external exe, can somebody tell me if I'm doing something wrong with the runtime and the process ?
  thanks.

• ffmped encoding with java using pipelines

  12 décembre 2015, par András

  Can I send pictures from my webcam to ffmpeg which give me back the encoded images in real time ? I dont want to use xuggle because it’s not supported in my arm based linux.