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• avcodec/amfenc_h264 : improve B-frame usability and simplify options

  16 mai, par Dmitrii Ovchinnikov

  avcodec/amfenc_h264 : improve B-frame usability and simplify options
   Query GPU caps for B-frame support and warn if unsupported.
  
   Make `-max_b_frames` optional
  
   Drop explicit `-pa_lookahead_buffer_depth` requirement in
  
  adaptive mode.
  

  • [DH] libavcodec/amfenc_h264.c

• What are VP9 Codec settings comparable to x264 encoder with preset=ultrafast setting regarding CPU ?

  11 juin 2021, par xKubo

  I'd like to replace the x264 codec [codec settings : preset=ultrafast] with the vp9 codec.
My primary requirement is that the encoding has less or approximately equal CPU,
while keeping the quality of the video roughly the same.
I tried the following settings, however my CPU is still roughly 30% higher.

  


  VP9 codec settings : crf=30;quality=realtime;speed=15;lag-in-frames=7

  


  x264 codec settings : preset=ultrafast;

  


  Is there any codec setting that can lower my CPU during encoding even more ?

  


  I am constrained to only a single thread.
Screenshot of my simple testing app

  


• Why a batch processing of ffmpeg is freezing the system ?

  3 septembre 2019, par Krishna Chebrolu

  I have a requirement of splitting smaller chunks of videos from 50+ mp4 source files for 5000+ records. Each record may result in 2 or 3 smaller chunks from as many source files out of those 50+.

  The logic to determine which source file to be picked up is written in Java and then fed to ffmpeg on Runtime.getRuntime().exec() using ExecutorService with newFixedThreadPool as below :

  private static boolean processqueue(ArrayList<string> cmds) {
  
      final ExecutorService pool;
  
      int threadsnum = Runtime.getRuntime().availableProcessors()-2;
  
      pool = Executors.newFixedThreadPool(threadsnum);
  
  
  
      for(final String cmd: cmds){ 
  
          pool.execute(new Runnable() {
  
              public void run() {
  
                  System.out.println(cmd);
  
                  try {
  
                      Runtime.getRuntime().exec(cmd);
  
                  } catch (IOException e) {
  
                      e.printStackTrace();
  
                      pool.shutdown();
  
                  }
  
              }
  
          });
  
      }                   
  
      pool.shutdown();
  
  
  
      // wait for them to finish for up to one minute.
  
      try {
  
          if(!pool.awaitTermination(1, TimeUnit.MINUTES)) {
  
              pool.shutdownNow();
  
          }
  
  
  
          //Wait a while for tasks to respond to being cancelled
  
          if(!pool.awaitTermination(1, TimeUnit.MINUTES))
  
              System.err.println("Pool did not shutdown properly");
  
  
  
      } catch (InterruptedException e) {
  
          e.printStackTrace();
  
          pool.shutdownNow();
  
          //Preserve interrupt status
  
          Thread.currentThread().interrupt();
  
          return false;
  
      }                   
  
  
  
      return true;
  
  }
  
  </string>

  the String cmd value is one of these based on split or merge requirement :

  for split :

  ffmpeg -y -ss 00:00:00 -t 00:08 -i E:/tmp/fin12.mp4 -acodec copy -vcodec copy E:/tmp/Intermed/0136f.mp4

  or

  for merge :

  ffmpeg -y -i E:/tmp/Inter/0136c0.mp4 -i E:/tmp/Inter/0136c1.mp4 -i E:/tmp/Inter/0136f.mp4 -i E:/tmp/Jingle.mp4 -i E:/tmp/wm1280.png -filter_complex "[0:v][0:a][1:v][1:a][2:v][2:a][3:v][3:a]concat=n=4:v=1:a=1[vv][a];[vv][4:v]overlay=x=0:y=H-overlay_h[v]" -map "[v]" -map "[a]" E:/tmp/final/0136.mp4

  On first attempt, only 250 records were processed. And, on subsequent attempt of balance records processing, it threw below exception ; but, processed another 300 records :

  java.io.IOException: Cannot run program "ffmpeg": CreateProcess error=1455, The paging file is too small for this operation to complete
  
  at java.lang.ProcessBuilder.start(Unknown Source)

  And, this code freezes often. Why is ExecutorService not holding up the queue to process all the records and exit gracefully ? What am I doing wrong ?

  Note : I’m calling Java class from windows batch script by passing relevant arguments which is executed from command line.