Detect FFmpeg installation and Version

Question

I'm writing a PHP script that converts uploaded video files to FLV on the fly, but I only want it to run that part of the script if the user has FFmpeg installed on the server.

Would there be a way to detect this ahead of time? Could I perhaps run an FFmpeg command and test whether it comes back "command not found?"

Answer 1

Try:

$ffmpeg = trim(shell_exec('which ffmpeg')); // or better yet:
$ffmpeg = trim(shell_exec('type -P ffmpeg'));

If it comes back empty ffmpeg is not available, otherwise it will hold the absolute path to the executable, which you may use in the actual ffmpeg call:

if (empty($ffmpeg))
{
    die('ffmpeg not available');
}

shell_exec($ffmpeg . ' -i ...');

Answer 2

The third parameter to the exec() function is the return value of the executed program. Use it like this:

exec($cmd, $output, $returnvalue);
if ($returnvalue == 127) {
    # not available
}
else {
    #available
}

This works on my Ubuntu box.