Newest 'ffmpeg' Questions - Stack Overflow

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• Filter the video while keeping the bitrate (FFmpeg) [migrated]

  20 décembre 2013, par Timofey

  For experimental purposes, I need to filter my video (using -vf option) and change, say, brightness, but keep the same bitrate as in original video.

  Just for testing purposes, I change RGB values to make video completely black using line like this:

  ffmpeg -i input.mp4 -vf lutrgb='r=0.0*val:g=0.0*val:b=0.0*val' output.mp4

  So far, I tried to specify bitrate manually by adding -b, -minrate/maxrate and -q options to this line, but no matter what I do, FFmpeg keep reducing the br of the output video to just a few kilobytes.

  And my question is - if it's possible to keep bitrate on the same level even if if I change RGB values to be completely black (as an extreme case).

• node js (or other) as streaming server

  20 décembre 2013, par Abdul Ali

  Apologies if a simple question but cannot find anything helpful . Am also new to the streaming concept.

  Goal is to set up a server which keeps on listening for data on a speific port. The user will be sending sequence of images from their iphone (# of images unknown).

  when the data is receieved, ffmpeg should start to get data from that port (as input) and send those images to ffserver to be streamed as a live video.

  did try Nginx-Rtmp module but the iphone developer have informed that in iphone, only ip and port can be given to open a stream (and no other part of the url can be given e.g. streamname and application name in case of nginx-rtmp)

  Any help and guide will be appreciatd that what can be used to set up a free and very simple sever that simply receives the images which ffmpeg can capture and send to ffserver .

• Java Runtime exec() get stuck after a while

  20 décembre 2013, par codareee

  I'm building a simple UI for ffmpeg launching ffmpeg.exe with parameters using exec(). it works on Os X but on Windows 7-8 after few seconds the ffmpeg process suspends itself and resumes only when I kill the father process. (also ddlhost.exe is created) Ffmpeg.exe converts successfully the same video from cmd.

  Searching on the internet I've found this answer but I have the same problem running a simple test program which is not using the Input and Error streams.

  Here is the test program code which has the same problem of the main one:

  public class Main {
  
  static String param_ffmpeg_1 = "./data/ffmpeg.exe";
  static String param_ffmpeg_2 = "-i";
  
  static String in = "./data/source.mov";
  static String out = "./data/out.flv";
  
  static Process p;
  
  public static void main(String[] args) {
  
      /*File f = new File(out);
  
      if (f.exists()){
          f.delete();
      }*/
  
  
      Runtime rt = Runtime.getRuntime() ;
      //String cmd1 =  param_ffmpeg_1 + param_ffmpeg_2 +  in_path +  param_ffmpeg_3 + out_path ;
      System.out.println(in);
      System.out.println(out);
      String[] cmd1 = new String[] { param_ffmpeg_1, param_ffmpeg_2, in, "-ar", "44100", "-vb", "2500k", "-s", "882x496", "-f", "flv", out};
  
      try {
          p = rt.exec(cmd1);
      } catch (IOException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
      }
      int r = 123456;
      try {
          r = p.waitFor();
      } catch (InterruptedException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
      }
  
      System.out.println(r);
  
  
  }
  

  }

• Can ffplay or VLC probe a network stream ?

  20 décembre 2013, par John Qualis

  I am using ffmpeg to stream video to a server intermittently. Once every 10-15 minutes. I am able to play the stream in ffplay and VLC when the stream is on. But when the stream is turned off and then back again after few minutes these players do not play the stream again without manual intervention. Is it possible for either of these players to poll the server periodically to check if a stream is available and play it?

• converted mp4 file using ffmpegvis not playing JW player

  20 décembre 2013, par shiva

  Just i converted mov video file to mp4 file using ffmpeg. But the converted file is not playing JW player. Actual mp4 file videos working fine in all browsers. Thanks for help.