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• Playing H.264 video in an application through ffmpeg using DXVA2 acceleration

  28 avril 2012, par cloudraven

  I am trying to output H.264 video in a Windows application. I am moderately familiar with FFMPEG and I have been successful at getting it to play H.264 in a SDL window without a problem. Still, I would really benefit from using Hardware Acceleration (probably through DXVA2)

  I am reading raw H264 video, no container, no audio ... just raw video (and no B-frames, just I and P). Also, I know that all the systems that will use this applications have Nvidia GPUs supporting at least VP3.
  Given that set of assumptions I was hoping to cut some corners, make it simple instead of general, just have it working for my particular scenario.

  So far I know that I need to set the hardware acceleration in the codec context by filling the hwaccel member through a call to ff_find_hwaccel. My plan is to look at Media Player Classic Home Cinema which does a pretty good job at supporting DXVA2 using FFMPEG when decoding H.264. However, the code is quite large and I am not exactly sure where to look. I can find the place where ff_find_hwaccel is called in h264.c, but I was wondering where else should I be looking at.

  More specifically, I would like to know what is the minimum set of steps that I have to code to get DXVA2 through FFMPEG working ?

  EDIT : I am open to look at VLC or anything else if someone knows where I can find the "important" piece of code that does the trick. I just mentioned MPC-HC because I think it is the easiest to get to compile in Windows.

• PHP - Read and write the same file hangs

  2 février 2016, par Adracat

  I’m trying to use FFMPEG to make some works with video on the server, and something I need to do is to get the progress of the process.

  I searched a little and I found this solution which tells to write the log into a file and then reading and parsing it.

  The problem

  What is driving me crazy is that I tell FFMPEG - with exec - (process A) to write the log into a file, but when I try to read it - with file_get_contents() - (process B) it does not show the contents until process A is finished (or interrupted the PHP script).

  So, when process A finishes or it says "PHP script timeout", then I can read the file as times as I want, refreshing the page (process B) and showing the contents at the time.

  What I’ve tried

  I’ve tried to use fopen() to create the file with w, w+ and a parameters, using - and without using - fclose(). I’ve tried to use also flock() just in case it gets faster to read to process B if it knows it’s already locked and does not have to wait, but then FFMPEG is not able to write into the file.

  I’ve searched for multithreading too, but I think there must be an easier and simpler way.

  I’ve used also CURL and HTTP context, as this link suggests, but no luck.

  I’ve tried, too, to use PHP-FFMPEG but it’s not supporting the last FFMPEG version, so I cannot use it.

  When I said before "(or interrupted the PHP script)" is because I tried to wait and, when PHP got a timeout, process B worked alright and the file was still updating.

  The code

  Process A (fileA.php)

  exec('ffmpeg -y -i input_file.mp4 output_file.avi 2> C:\Full\Path\To\File\log.txt 1>&2');

  Process B (fileB.php)

  $content = file_get_contents($file);
  
  
  
  if($content){
  
      //get duration of source
  
      preg_match("/Duration: (.*?), start:/", $content, $matches);
  
  
  
      $rawDuration = $matches[1];
  
  
  
      //rawDuration is in 00:00:00.00 format. This converts it to seconds.
  
      $ar = array_reverse(explode(":", $rawDuration));
  
      $duration = floatval($ar[0]);
  
      if (!empty($ar[1])) $duration += intval($ar[1]) * 60;
  
      if (!empty($ar[2])) $duration += intval($ar[2]) * 60 * 60;
  
  
  
      //get the time in the file that is already encoded
  
      preg_match_all("/time=(.*?) bitrate/", $content, $matches);
  
  
  
      $rawTime = array_pop($matches);
  
  
  
      //this is needed if there is more than one match
  
      if (is_array($rawTime)){$rawTime = array_pop($rawTime);}
  
  
  
      //rawTime is in 00:00:00.00 format. This converts it to seconds.
  
      $ar = array_reverse(explode(":", $rawTime));
  
      $time = floatval($ar[0]);
  
      if (!empty($ar[1])) $time += intval($ar[1]) * 60;
  
      if (!empty($ar[2])) $time += intval($ar[2]) * 60 * 60;
  
  
  
      //calculate the progress
  
      $progress = round(($time/$duration) * 100);
  
  
  
      echo "Duration: " . $duration . "<br />";
  
      echo "Current Time: " . $time . "<br />";
  
      echo "Progress: " . $progress . "%";
  
  
  
  }

  The process

  I just open fileA.php on a Chrome tab and, after a few seconds, I open fileB.php on another Chrome tab (and it stays as loading).

  What I need

  I need to be able to load the file and show the information I want to show while the file is being written (by exec and FFMPEG or other PHP scripts), so I can update the progress percentage with some AJAX calls.

  Extra information

  At this point, I’m using PHP 5.4 on a IIS 7.5 with Windows 7 Professional.

  Thank you everyone for your time, help and patience !

  Best regards.

• FFMPEG (2.5.7 ) Progress Bar from PHP

  6 mars 2016, par kunal

  i want to have the Progress bar of FFmpeg encoding.This is the Code which i am using to get the percentage value of encoding Process.

  <?php
  
  $content = @file_get_contents("with-logo/output.txt");
  
  //echo $content;
  
  if($content) {
  
      preg_match("/Duration: (.*?), start:/", $content, $matches);
  
  
  
      $rawDuration = $matches[1];
  
  
  
      $ar = array_reverse(explode(":", $rawDuration));
  
      $duration = floatval($ar[0]);
  
      //echo $duration;
  
      if (!empty($ar[1])) $duration += intval($ar[1]) * 60;
  
      if (!empty($ar[2])) $duration += intval($ar[2]) * 60 * 60;
  
  
  
      //get the time in the file that is already encoded
  
      preg_match_all("/time=(.*?) bitrate/", $content, $matches);
  
  
  
      $rawTime = array_pop($matches);
  
  
  
      //this is needed if there is more than one match
  
      if (is_array($rawTime)){$rawTime = array_pop($rawTime);}
  
  
  
      //rawTime is in 00:00:00.00 format. This converts it to seconds.
  
      $ar = array_reverse(explode(":", $rawTime));
  
      $time = floatval($ar[0]);
  
      if (!empty($ar[1])) $time += intval($ar[1]) * 60;
  
      if (!empty($ar[2])) $time += intval($ar[2]) * 60 * 60;
  
  
  
      //calculate the progress
  
      $progress = round(($time/$duration) * 100);
  
  
  
      echo "Duration: " . $duration . "<br />";
  
      echo "Current Time: " . $time . "<br />";
  
      echo "Progress: " . $progress . "%";
  
  }
  
  ?> 

  here is relevant log line form my FFMPEG Log files for Better Understanding.

  Stream mapping:
  
    Stream #0:0 -> #0:0 (mpeg2video (native) -> h264 (libx264))
  
    Stream #0:1 -> #0:1 (pcm_s24le (native) -> aac (native))
  
  Press [q] to stop, [?] for help
  
  
  
  frame=   11 fps=0.0 q=0.0 size=       0kB time=00:00:00.41 bitrate=   0.9kbits/s    
  
  frame=   22 fps= 21 q=0.0 size=       0kB time=00:00:00.85 bitrate=   0.4kbits/s    
  
  frame=   33 fps= 21 q=0.0 size=       0kB time=00:00:01.30 bitrate=   0.3kbits/s    
  
  frame=   43 fps= 20 q=0.0 size=       0kB time=00:00:01.69 bitrate=   0.2kbits/s   

  and this code is not returning the Value for Duration and as a result of this i am getting PHP warning and code is not calculating the Current percentage.

  here is the PHP warning , which i am getting-

  PHP Warning:  Division by zero in /var/www/html/mm/progressbar.php

  i think we can also calculate the percentage from the timebut i have no idea, how can i make it work ?

  or any help to solve the Problem with Duration.

  thanks for the help !