PHP实现获取FLV文件的时间

<?php
functionBigEndian2Int($byte_word,$signed=false)
{
??? $int_value??? =0;
??? $byte_wordlen=strlen($byte_word);
??? for($i=0;$i<$byte_wordlen;$i++){
??????? $int_value+=ord($byte_word{$i})*pow(256,($byte_wordlen-1-$i));
??? }
??? if($signed){
??????? $sign_mask_bit=0x80<<(8*($byte_wordlen-1));
??????? if($int_value&$sign_mask_bit){
??????????? $int_value=0-($int_value&($sign_mask_bit-1));
??????? }
??? }
??? return$int_value;
}
?
functiongetTime($name)
{
??? if(!file_exists($name)){
??????? return;
??? }
??? $flv_data_length=filesize($name);
??? $fp????????????? =@fopen($name,'rb');
??? $flv_header????? =fread($fp,5);
??? fseek($fp,5,SEEK_SET);
??? $frame_size_data_length? =BigEndian2Int(fread($fp,4));
??? $flv_header_frame_length=9;
??? if($frame_size_data_length>$flv_header_frame_length){
??????? fseek($fp,$frame_size_data_length-$flv_header_frame_length,SEEK_CUR);
??? }
??? $duration=0;
??? while((ftell($fp)+1)<$flv_data_length){
??????? $this_tag_header=fread($fp,16);
??????? $data_length???? =BigEndian2Int(substr($this_tag_header,3));
??????? $timestamp?????? =BigEndian2Int(substr($this_tag_header,8,3));
??????? $next_offset???? =ftell($fp)-1+$data_length;
??????? if($timestamp>$duration){
??????????? $duration=$timestamp;
??????? }
??????? fseek($fp,$next_offset,SEEK_SET);
??? }
??? fclose($fp);
??? return$duration;
}
?
functionget_flv_file_time($time)
{
$time=getTime($time);
??? $num=$time;
??? $sec=intval($num/1000);
??? $h?? =intval($sec/3600);
??? $m?? =intval(($sec%3600)/60);
??? $s?? =intval(($sec%60));
??? $tm? =$h.':'.$m.':'.$s;
??? return$tm;
}
?
?>