อยากถามคนเคยใช้ ffmpeg-php อ่ะครับ คือผมรันไม่ผ่าน

extension_loaded('ffmpeg') or die('Error in loading ffmpeg');
    $mov = new ffmpeg_movie("output.flv");
    printf("file name = %s\n", $mov->getFileName());
    printf("duration = %s seconds\n", $mov->getDuration());
    printf("frame count = %s\n", $mov->getFrameCount());
    printf("frame rate = %0.3f fps\n", $mov->getFrameRate());
    printf("comment = %s\n", $mov->getComment());
    printf("title = %s\n", $mov->getTitle());
    printf("author = %s\n", $mov->getAuthor());
    printf("copyright = %s\n", $mov->getCopyright());
    printf("get bit rate = %d\n", $mov->getBitRate());
    printf("has audio = %s\n", $mov->hasAudio() == 0 ? 'No' : 'Yes');