php exec执行视频图片转换

<?php

set_time_limit(0) ;



$cmd = "ffmpeg -i 'input/3.mp4' -r 1 -q:v 2 -f image2 images/pic-%03d.jpeg";

exec($cmd . " >> /var/log/php/cmd.log 2>&1",$log, $status);
if($status == 0){
    var_dump("执行成功");
} else {
    var_dump("执行失败");
}