Sur d’autres sites (10384)

• How to Terminate a Process Normally Created using ProcessBuilder

  30 janvier 2015, par Bilal Ahmed Yaseen

  I am creating Processes using ProcessBuilder in my Java Application. The created process executes some FFMPEG commands which actually copy the RTSP streams in specified destination media file.

  ProcessBuilder builder = new ProcessBuilder("ffmpeg", "-i", RTSP_URL, "-f", fileFormat, destFilePath);
  
  Process processToExecute = builder.start();

  I want to close the process before it completes its execution. So, If I run this FFMPEG command directly in windows CMD and then press ’CTRL+C’ after 5 seconds then process get terminates with status ’2’. And I can play the media file created so far.

  So, If I do the same operation in my Java Application using :

   process.destroy(); //I call this method after 5 sec

  I get the status code ’1’ which means abnormal termination. I get the status by the following way :

   processToExecute.destroy();
  
   processToExecute.exitValue(); //This return me status '1'

  And I can’t play the media file and I think this is due to the abnormal termination of the process.

  So how I can terminate the process created using ProcessBuilder in the same way we do in CMD with (CTRL+C) so that I may play the created media file ?

  I want to terminate process (created using ProcessBuilder) in Java Application with status code of ’2’ that I get when I terminate process using CMD.

  EDIT#01 : --- Sharing Findings

  So, when I try to delete that file once app terminates, I get the following error :

  The Action Can't be Performed Because File is Opened in FFMPEG.exe

  Which means that process is not terminating the command it is executing. That command still has occupied this file that’s why I am not getting able to play it. Process gets terminate when I call :

   processToExecute.destroy();

  But, the task it is performing (that is execution of a command) is still active. Strange !!!!

  EDIT#02 : Sharing Ultimate Reason

  Actually If I directly press ’CTRL+C’ or ’q’ in cmd when process is running then it terminates the process successfully and this process is no more visible in the currently executing processes lists.

  And Programatically when I call method :

  cmd> processToExecute.destroy();

  It terminates the process but when I see the list of currently executing processes I can still see them over there.

  And same scenario exists If I try to terminate this process using ’taskkill’ or ’kill’ command in another CMD by specifying their’s name or pid that still process terminates abnormally.

  P.S. I use the following command to see the running processes :

  tasklist

  So from this it proves that destroy() method from Application and ’taskkill or kill’ command from another CMD is not terminating the process normally that pressing ’CTRL+C’ and ’q’ does.

• Is there is another way to know why encoding fails besides got_packet_ptr param ?

  9 décembre 2012, par theateist

  I try to create video from jpeg images(using libavcodec), so I use this function for encoding :

  int avcodec_encode_video2(AVCodecContext* avctx, AVPacket* avpkt, const AVFrame* frame, int* got_packet_ptr);

  The problem is that for first 47 images the got_packet_ptr is 0. As I understood from documentation this means that the packet is empty and therefore I cannot use it. So, basically, I lose first 47 images and I don't know why encoding fails on those 47 images !

  got_packet_ptr = 0 doesn't tell me many about the problem ! So, how I can find the problem why 47 images does not succeed to encode ?

• is there a way to preload low quality in MPEG Dash or HLS so there is always something to play ?

  5 mars 2018, par Daniel Benedykt

  I created HLS manifests and DASH manifests with different resolutions and bitrates.

  The videos almost always starts low quality, then picks up quality/resolution.

  But later, if Internet speed drops, the video stops because its playing the hi resolution video.

  is there a way to preload low quality in MPEG DASH or HLS so there is always something to play ?

  Edit : I have the video preloaded. its not live streaming but once it starts playing, I am looking for a consistent stream, even if that means sacrificing quality.