Question

Hi I am using the following ffmpeg command to extract a thumbnail from the beginning of a clip with ffmpeg:

/usr/local/bin/ffmpeg -ss 00:00:1 -i $fileName.flv -s 150x100 -vframes 1 $fileName.jpg

Is it posible to extract a thumbnail from the middle of the clips duration with ffmpeg alone?

Each clip is of a different length.

If ffmpeg does not supply this option, I know it is possible to get the clips duration into this type of format 00:00:01.26 and then I suppose I can divide it in half, but I am not sure if this is the best approach, and I am also (embarrassed to say) not entirely sure how to divide that format in half with PHP.

Example code would be appreciated.

Thank you.

Answer 1

You can get the middle like this:

<?php
// get duration
$time =  exec("/local/bin/ffmpeg -i $fileName.flv 2>&1 | grep 'Duration' | cut -d ' ' -f 4 | sed s/,//");   

// duration in seconds; half the duration = middle
$duration = explode(":",$time);   
$durationInSeconds = $duration[0]*3600 + $duration[1]*60+ round($duration[2]);
$durationMiddle = $durationInSeconds/2;

// recalculte to minutes and seconds
$minutes = $durationMiddle/60;
$realMinutes = floor($minutes);
$realSeconds = round(($minutes-$real_minutes)*60);
?>

And then use your command with $realMinutes and $realSeconds :

/usr/local/bin/ffmpeg -ss $realMinutes:$realSeconds:1 -i $fileName.flv -s 150x100 -vframes 1 $fileName.jpg