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• How to terminate an infinite process with an specific time duration

  3 janvier 2014, par poc

  I tried to run hundreds of commands in a batch.

  So I have to let each command can be terminated under an duration, and then executes the next.

  However, the command will be terminated, because the timeout option argument is not working for ffmpeg

  So I wonder is there any workaround that can terminate an command within an time duration.

  I can terminate the command (which is running in foreground) by type 'q'

  def get_video_clip(self, rtsp_link="rtsp://localhost:554", f_name="sample", period=5):
  
          cmd = "ffmpeg -i {0} -acodec copy -vcodec copy {1}.mp4 -t {2}".format(  rtsp_link,
  
                                                                                  f_name,
  
                                                                                  period
  
                                                                                  )
  
          ap(cmd)
  
  
  
          os.popen(cmd)
  
          pass

  I attempted to capture streaming via rtsp and limit the clip duration under 3 sec

  But the option doesn't work. The ffmpeg won't be terminated anymore.

  Is there any workaround to fix the problem.

  Because I have to run hundreds of similar commands in a batch with Python script.

  ffmpeg -loglevel verbose   -i rtsp://172.19.1.42/live.sdp -acodec copy -vcodec copy  c0_s1_h264_640x480_30_vbr_500_99_40000000.mp4 -timeout 3 -y

  $ ffmpeg -h ffmpeg version 1.2.4 Copyright (c) 2000-2013 the FFmpeg
  developers built on Nov 22 2013 11:59:59 with Apple LLVM version 5.0
  (clang-500.2.79) (based on LLVM 3.3svn)

  The detailed log at https://gist.github.com/poc7667/8234701

• FFMpeg kmsgrab record pixels wrong

  21 avril 2020, par Alex Joel

  ffmpeg -f kmsgrab -i - -framerate 60 -vf 'hwdownload,format=bgr0' -preset ultrafast out.mkv

  



  This is how a video frame should look like

This is how it is recorded by ffmpeg
https://drive.google.com/file/d/11jOUTk3ZxOfwnfd7zS4d4qBLApTS3Vmx/view?usp=sharing

  


• issue starting ffmpeg screen capture on OSX (AVFoundation) from Java

  24 juin 2022, par stewori

  I would like to launch from Java on OSX a screen capture command like explained here : https://trac.ffmpeg.org/wiki/Capture/Desktop

  



  It works fine from the terminal. But when I launch exactly the same command using Java's Runtime.exec I get the following output :

  



  [AVFoundation input device @ 0x7f892f500400] Video device not found

'1:': Input/output error


  



  Assume the command I run is stored as String cmd = "ffmpeg -f avfoundation -i '1:' output.mkv". Things I tried :

  



  


  • Using ffmpeg -f avfoundation -list_devices true -i "" I asserted that 1 is the correct index for the screen. I ran that command also via Runtime.exec and it gives the same indexes as when I run it from terminal.

  


  • It does not make a difference whether I use '1:' or "\"1:\"". Well, in the latter case it says "1:": Input/output error. Both variants work in terminal.

  


  • Neither does it make a difference whether I call
Runtime.getRuntime().exec(cmd),
Runtime.getRuntime().exec(cmd.split(" ")) or (new ProcessBuilder(cmd.split(" "))).start(). In principle it starts ffmpeg and that terminates with the output given above.

  


  • It does not seem to make a difference whether I read out ffmpeg's output or not (via process.getErrorStream())

  


  • The only thing that works is to store the command in a file, e.g. in run.sh and then call e.g. Runtime.getRuntime().exec("run.sh"). It should be possible to execute this properly from Java without this kind of workaround, right ? What am I doing wrong ?

  


  • On Linux, using e.g. ffmpeg -video_size 1024x768 -framerate 25 -f x11grab -i :0.0+100,200 output.mp4 it works fine, from command line or from Java, with Runtime.exec and via ProcessBuilder.

  


  



  I did not try it on Windows. On OSX (Mojave 10.14.5) I used Java 12, on Linux (Mint 18, 64bit) Java 8. Would be some hassle to try it with Java 12 on Linux and I suspect the Java version is not the cause, given that avfoundation vs x11grab is the far more dominant difference.