用PHP读取flv文件的播放时间长度

复制代码 代码如下:

  <?php

  // +----------------------------------------------------------------------+

  // | PHP version 4&5 |

  // +----------------------------------------------------------------------+

  // | Copyright (c) 2007 [email protected] |

  // +----------------------------------------------------------------------+

  // | This source file's function is to get the time length of flv |

  // | main function getTime param:$name The flv file you want to get |

  // +----------------------------------------------------------------------+

  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;

  }

  function getTime($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, 5, 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;

  }

  ?>