PHP使用ffmpeg给视频增加字幕显示的方法

<?php
$dir = './'; // set to current folder
if ($handle = opendir($dir)) {
?while(false!== ($file = readdir($handle))) {
?if ( is_file($dir.$file) ){
?if (preg_match("'.(avi)$'",$file) ){
?$sub_file = str_ireplace(".avi",".srt",$dir.$file);
?$idx_file = str_ireplace(".avi",".idx",$dir.$file);
?$thumb_file = str_ireplace(".avi",".jpg",$dir.$file);
?$out_file = str_ireplace(".avi",".mp4",$dir.$file);
?flv_convert_get_thumb($dir.$file,$sub_file,$idx_file,$thumb_file,$out_file);
?}
?else{
?continue;
?}
?}
?}
?closedir($handle);
}
//flv_convert_get_thumb('input.avi','input.srt','output.jpg','output.ogm');
// code provided and updated by steve of phpsnaps ! thanks
// accepts:
// 1: the input video file
// 2: path to thumb jpg
// 3: path to transcoded mpeg?
function flv_convert_get_thumb($in,$in_sub,$in_idx,$out_thumb,$out_vid){
?// get thumbnail
?$cmd = 'ffmpeg -v 0 -y -i '.$in.' -vframes 1 -ss 250 -vcodec mjpeg -f rawvideo -s 286x160 -aspect 16:9 '.$out_thumb;
?$res = shell_exec($cmd);
?// $res is the output of the command
?// transcode video
$cmd = 'mencoder '.$in.' -o '.$out_vid.' -sub '.$in_sub.' -subfont-text-scale 3.0 -subpos 99 -af volume=10 -aspect 16:9 -of avi -noodml -ovc x264 -x264encop$
?$res = shell_exec($cmd);
}
?>