ffmpeg video thumbnail / screenshot class [ technoslab ]

<?php

# usage : http://technoslab.blogspot.com
#
# tecShot::genThumb('e:\video\b.avi',9,'e:\video\ffmpeg.exe');
#
# Class

final class tecShot{

    private function error($msg){
        exit("<b>tecShot</b>: $msg");
    }

    public function genThumb($video_path,$ss_no,$ffmpeg_path="/usr/local/bin/ffmpeg"){

    if(!is_file($video_path)){
            $this->error("'$video_path' contains no such video.");
        }

        if($ss_no<=0){
            $this->error("'$ss_no' is less that or equal to 0.");
        }

        if($ss_no>50){
            $this->error("You can't generate more than 50 thumbs at a time.");
        }

        if(!is_dir("./thumb")){
            $this->error("Create a folder with proper permissions and rename it to '<b>thumb</b>'.");
        }

        ob_start();
        passthru("{$ffmpeg_path} -i \"$video_path\" 2>&1");
        $duration = ob_get_contents();
        ob_end_clean();
        $search='@Duration: ([^:]*):([^:]*):([^(:|.)]*)(.[^,]*|)@is';
        preg_match($search, $duration, $matches);
        $hr=$matches[1];
        $min=$matches[2];
        $sec=$matches[3];
        $tot = $hr * 3600 + $min * 60 + $sec;
        $r=round($ss_no/$tot,2);
        $name = "thumb/".basename($video_path)."_";
        ob_start();
        $exec="{$ffmpeg_path} -i \"{$video_path}\" -r $r -vframes $ss -an -y \"$name%d.png\" 2>&1";
        passthru($exec);
        $duration = ob_get_contents();
        ob_end_clean();

        for($i=1;$i<=$ss_no;$i++){
            $newName = $name.$i.".png";
            echo "&nbsp;&nbsp;<img src='$newName' style='max-width:300px' />";
            if($i%3==0)echo"<br />";

        }

    }
}

?>