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• ffmpeg - extract exact number of frames from video

  29 mars 2017, par Michael B

  I want to create a maximum of 30 images from a video (and tile them for a sprite sheet).

  I’ve tried using the ’select’ with ’mod’ but if the total number of frames does not fit neatly into the desired number of images (30) then I sometimes end up with more images, sometimes less.

  For example if my video is 72 frames long, my ’mod’ would be 72 / 30, which is 2.4.

  I’m running this from a python script so i’m doing something like the following for the filter :

  select='not(mod(n\," + str(mod) + "))'

  I think the mod has to be an integer (?) so I could either round down and use 2 which gives me 36 images or round up which gives me 24 images

  Whats the best way to get exactly 30 ? - obviously the interval wouldn’t be identical but thats fine.

  Maybe I could use a for loop to generate a list of the frames closest to the desired interval and then pass that in as the select filter ?

  e.g. to get the frames I would do something like this :

  nframes = 72 # number of frames in video
  
  outImages = 30 # number of images I want
  
  mod = float(nframes) / outImages # 2.4
  
  
  
  frames = []
  
  
  
  idx = 1
  
  
  
  while i < nframes:
  
      print str(idx) + ": " + str(math.floor(i+0.5)) 
  
      frames.append(int(math.floor(i+0.5)))
  
      idx += 1
  
      i += mod

  Then am I able to pass that (the frames list) into the ffmpeg command ? Or can I tell ffmpeg to do something similar ?

• ffmpeg Progress Bar - Encoding Percentage in PHP

  11 juillet 2016, par Jimbo

  I’ve written a whole system in PHP and bash on the server to convert and stream videos in HTML5 on my VPS. The conversion is done by ffmpeg in the background and the contents is output to block.txt.

  Having looked at the following posts :

  Can ffmpeg show a progress bar ?

  and

  ffmpeg video encoding progress bar

  amongst others, I can’t find a working example.

  I need to grab the currently encoded progress as a percentage.

  The first post I linked above gives :

  $log = @file_get_contents('block.txt');
  
  
  
  preg_match("/Duration:([^,]+)/", $log, $matches);
  
  list($hours,$minutes,$seconds,$mili) = split(":",$matches[1]);
  
  $seconds = (($hours * 3600) + ($minutes * 60) + $seconds);
  
  $seconds = round($seconds);
  
  
  
  $page = join("",file("$txt"));
  
  $kw = explode("time=", $page);
  
  $last = array_pop($kw);
  
  $values = explode(' ', $last);
  
  $curTime = round($values[0]);
  
  $percent_extracted = round((($curTime * 100)/($seconds)));
  
  
  
  echo $percent_extracted;

  The $percent_extracted variable echoes zero, and as maths is not my strong point, I really don’t know how to progress here.

  Here’s one line from the ffmpeg output from block.txt (if it’s helpful)

  time=00:19:25.16 bitrate= 823.0kbits/s frame=27963 fps= 7 q=0.0 size=
  117085kB time=00:19:25.33 bitrate= 823.1kbits/s frame=27967 fps= 7
  q=0.0 size= 117085kB time=00:19:25.49 bitrate= 823.0kbits/s
  frame=27971 fps= 7 q=0.0 size= 117126kB

  Please help me output this percentage, once done I can create my own progress bar. Thanks.

• ffmpeg Progress Bar - Encoding Percentage in PHP

  24 mars 2019, par Jimbo

  I’ve written a whole system in PHP and bash on the server to convert and stream videos in HTML5 on my VPS. The conversion is done by ffmpeg in the background and the contents is output to block.txt.

  Having looked at the following posts :

  Can ffmpeg show a progress bar ?

  and

  ffmpeg video encoding progress bar

  amongst others, I can’t find a working example.

  I need to grab the currently encoded progress as a percentage.

  The first post I linked above gives :

  $log = @file_get_contents('block.txt');
  
  
  
  preg_match("/Duration:([^,]+)/", $log, $matches);
  
  list($hours,$minutes,$seconds,$mili) = split(":",$matches[1]);
  
  $seconds = (($hours * 3600) + ($minutes * 60) + $seconds);
  
  $seconds = round($seconds);
  
  
  
  $page = join("",file("$txt"));
  
  $kw = explode("time=", $page);
  
  $last = array_pop($kw);
  
  $values = explode(' ', $last);
  
  $curTime = round($values[0]);
  
  $percent_extracted = round((($curTime * 100)/($seconds)));
  
  
  
  echo $percent_extracted;

  The $percent_extracted variable echoes zero, and as maths is not my strong point, I really don’t know how to progress here.

  Here’s one line from the ffmpeg output from block.txt (if it’s helpful)

  time=00:19:25.16 bitrate= 823.0kbits/s frame=27963 fps= 7 q=0.0 size=
  117085kB time=00:19:25.33 bitrate= 823.1kbits/s frame=27967 fps= 7
  q=0.0 size= 117085kB time=00:19:25.49 bitrate= 823.0kbits/s
  frame=27971 fps= 7 q=0.0 size= 117126kB

  Please help me output this percentage, once done I can create my own progress bar. Thanks.