title: php and ffmpeg from command line in windows - not working, nothing returns
body: <p>I'm trying to execute ffmpeg within a website and it never output's a file, nothing return's, I have tried it with parameters -version and that works fine.
  I can copy and paste the main command into dos and it also works fine.</p>
  
  <p>I'm stuck, I have tried many things including shell_exec  but to no avail, nothing comes back other than array(0) { } int(0). help?</p>
  
  <pre><code> //$cmd = 'C:\ffmpeg.exe ffmpeg -version';
   $cmd = "C:\ffmpeg.exe -i C:\1.mp3 -i C:\2.mp3 -filter_complex amerge -c:a libmp3lame -q:a 4 C:\out.mp3";
   echo exec($cmd, $o, $v);
   var_dump($o);
   var_dump($v);
  </code></pre>