无法使用exec命令来使用ffmpeg

I am researching over ffmpeg usage for quite a while and seemed little confusing to me. Finally I found that exec command of PHP could help in execution of ffmpeg command if ffmpeg is installed on the system . I created the php script below:

  exec("ffmpeg -i C:\Users\sameeksha\Downloads\v.mp4 -ar 22050 -ab 32 -f flv -s 320x240 C:\FFMPEG\video.flv", $output, $return);

     if($return) {
        echo "created ".$output;     
    }
    else 
        echo "not ".$output;

The same command run from command line is creating the converted video, but when I run it as a PHP script it does not. I even installed dll files for ffmpeg but still did not work for me.

Any help would be appreciated.

You need to escape the backslashes in a double quoted string.

Example: C:\FFMPEG\video.flv needs to be C:\\FFMPEG\\video.flv

Or just use slashes: C:/FFMPEG/video.flv

You can also enclose your command in apostrophes rather than quotes, as the apostrophe inhibits escape sequences providing \ is not the last character in your input.

exec('ffmpeg -i ... ',  $output, $return);