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• avcodec/hw_base_encode : Add missing include

  2 juillet 2024, par Andreas Rheinhardt

  avcodec/hw_base_encode : Add missing include
  Fixes checkheaders.
  Reviewed-by : Sean McGovern <gseanmcg@gmail.com>
  
  Reviewed-by : Tong Wu <wutong1208@outlook.com>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavcodec/hw_base_encode.h

• How to interpret ffmpeg -pix_fmts output ?

  11 août 2015, par RichAmberale

  Running ffmpeg -pix_fmts returns a list of formats. Snip :

  IO... yuv444p16be            3            48
  
  ..H.. vdpau_mpeg4            0             0
  
  ..H.. dxva2_vld              0             0
  
  IO... rgb444le               3            12
  
  IO... rgb444be               3            12
  
  IO... bgr444le               3            12

  What do the I O and H on the right side mean ? What are the numbers in the 2 leftmost columns ?

• How to stop perl buffering ffmpeg output

  4 février 2017, par Sebastian King

  I am trying to have a Perl program process the output of an ffmpeg encode, however my test program only seems to receive the output of ffmpeg in periodic chunks, thus I am assuming there is some sort of buffering going on. How can I make it process it in real-time ?

  My test program (the tr command is there because I thought maybe ffmpeg’s carriage returns were causing perl to see one big long line or something) :

  #!/usr/bin/perl
  
  
  
  $i = "test.mkv"; # big file, long encode time
  
  $o = "test.mp4";
  
  
  
  open(F, "-|", "ffmpeg -y -i '$i' '$o' 2>&1 | tr '\r' '\n'")
  
          or die "oh no";
  
  
  
  while(<f>) {
  
          print "A12345: $_"; # some random text so i know the output was processed in perl
  
  }
  
  </f>

  Everything works fine when I replace the ffmpeg command with this script :

  #!/bin/bash
  
  
  
  echo "hello";
  
  
  
  for i in `seq 1 10`; do
  
          sleep 1;
  
          echo "hello $i";
  
  done
  
  
  
  echo "bye";

  When using the above script I see the output each second as it happens. With ffmpeg it is some 5-10 seconds or so until it outputs and will output sometimes 100 lines each output.

  I have tried using the program unbuffer ahead of ffmpeg in the command call but it seems to have no effect. Is it perhaps the 2>&1 that might be buffering ?
  Any help is much appreciated.

  If you are unfamiliar with ffmpeg’s output, it outputs a bunch of file information and stuff to STDOUT and then during encoding it outputs lines like

  frame=  332 fps= 93 q=28.0 size=     528kB time=00:00:13.33 bitrate= 324.2kbits/s speed=3.75x

  which begin with carriage returns instead of new lines (hence tr) on STDERR (hence 2>&1).