Use FFMpeg to get middle frame of a video?

ffmpeg, video

Solution

This could be simplified, but here's some old PHP code I had lying around that should do the trick. (Add the location to ffmpeg if it's not in your path)

$output = shell_exec("ffmpeg -i {$path}");
preg_match('/Duration: ([0-9]{2}):([0-9]{2}):([^ ,])+/', $output, $matches);
$time = str_replace("Duration: ", "", $matches[0]);
$time_breakdown = explode(":", $time);
$total_seconds = round(($time_breakdown[0]*60*60) + ($time_breakdown[1]*60) + $time_breakdown[2]);
shell_exec("ffmpeg -y  -i {$path} -f mjpeg -vframes 1 -ss " . ($total_seconds / 2) . " -s {$w}x{$h} {$output_filename}");

Problem

I'm wondering how to use FFMpeg to grap the middle frame of a video. I've already written the C# to grab a frame at a certain time (ie pull one frame at second 3). But I've yet to figure out how to find the middle of video using the FFMpeg commands.

Original source