利用php获得flv视频长度的实例代码

 function BigEndian2Int($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 $int_value; } //获得视频的数字时间 function getFlvDuration($name){   if(!file_exists($name)){     return;   }   $flv_data_length=filesize($name);   $fp = @fopen($name, 'r');   $flv_header = fread($fp, 5);   fseek($fp, 5, SEEK_SET);   $frame_size_data_length = $this->BigEndian2Int(fread($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     = $this->BigEndian2Int(substr($this_tag_header, 5, 3));      $timestamp      = $this->BigEndian2Int(substr($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 $duration; } //转化为0：03：56的时间格式 function getFlvTime($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; }