php获取mp3音频信息实例教程

php获取mp3音频信息

很早之前在网上看到一个获取 MP3 音频信息的 php 类。如：播放时长、文件大小、文件编码等等

<?php class mp3file {     protected $block;     protected $blockpos;     protected $blockmax;     protected $blocksize;     protected $fd;     protected $bitpos;     protected $mp3data;     public function __construct($filename)     {         $this->powarr  = array(0=>1,1=>2,2=>4,3=>8,4=>16,5=>32,6=>64,7=>128);         $this->blockmax= 1024;                  $this->mp3data = array();         $this->mp3data['Filesize'] = filesize($filename);         $this->fd = fopen($filename,'rb');         $this->prefetchblock();         $this->readmp3frame();     }     public function __destruct()     {         fclose($this->fd);     }     //-------------------     public function get_metadata()     {         return $this->mp3data;     }     protected function readmp3frame()     {         $iscbrmp3=true;         if ($this->startswithid3())             $this->skipid3tag();         else if ($this->containsvbrxing())         {             $this->mp3data['Encoding'] = 'VBR';             $iscbrmp3=false;         }         else if ($this->startswithpk())         {             $this->mp3data['Encoding'] = 'Unknown';             $iscbrmp3=false;         }              if ($iscbrmp3)         {             $i = 0;             $max=5000;             //look in 5000 bytes...              //the largest framesize is 4609bytes(256kbps@8000Hz  mp3)             for($i=0; $i<$max; $i++)             {                 //looking for 1111 1111 111 (frame synchronization bits)                                 if ($this->getnextbyte()==0xFF)                     if ($this->getnextbit() && $this->getnextbit() && $this->getnextbit())                         break;             }             if ($i==$max)                 $iscbrmp3=false;         }              if ($iscbrmp3)         {             $this->mp3data['Encoding'         ] = 'CBR';             $this->mp3data['MPEG version'     ] = $this->getnextbits(2);             $this->mp3data['Layer Description'] = $this->getnextbits(2);             $this->mp3data['Protection Bit'   ] = $this->getnextbits(1);             $this->mp3data['Bitrate Index'    ] = $this->getnextbits(4);             $this->mp3data['Sampling Freq Idx'] = $this->getnextbits(2);             $this->mp3data['Padding Bit'      ] = $this->getnextbits(1);             $this->mp3data['Private Bit'      ] = $this->getnextbits(1);             $this->mp3data['Channel Mode'     ] = $this->getnextbits(2);             $this->mp3data['Mode Extension'   ] = $this->getnextbits(2);             $this->mp3data['Copyright'        ] = $this->getnextbits(1);             $this->mp3data['Original Media'   ] = $this->getnextbits(1);             $this->mp3data['Emphasis'         ] = $this->getnextbits(1);             $this->mp3data['Bitrate'          ] = mp3file::bitratelookup($this->mp3data);             $this->mp3data['Sampling Rate'    ] = mp3file::samplelookup($this->mp3data);             $this->mp3data['Frame Size'       ] = mp3file::getframesize($this->mp3data);             $this->mp3data['Length'           ] = mp3file::getduration($this->mp3data,$this->tell2());             $this->mp3data['Length mm:ss'     ] = mp3file::seconds_to_mmss($this->mp3data['Length']);                          if ($this->mp3data['Bitrate'      ]=='bad'     ||                 $this->mp3data['Bitrate'      ]=='free'    ||                 $this->mp3data['Sampling Rate']=='unknown' ||                 $this->mp3data['Frame Size'   ]=='unknown' ||                 $this->mp3data['Length'     ]=='unknown')             $this->mp3data = array('Filesize'=>$this->mp3data['Filesize'], 'Encoding'=>'Unknown');         }         else         {             if(!isset($this->mp3data['Encoding']))                 $this->mp3data['Encoding'] = 'Unknown';         }     }     protected function tell()     {         return ftell($this->fd);     }     protected function tell2()     {         return ftell($this->fd)-$this->blockmax +$this->blockpos-1;     }     protected function startswithid3()     {         return ($this->block[1]==73 && //I                 $this->block[2]==68 && //D                 $this->block[3]==51);  //3     }     protected function startswithpk()     {         return ($this->block[1]==80 && //P                 $this->block[2]==75);  //K     }     protected function containsvbrxing()     {         //echo "<!--".$this->block[37]." ".$this->block[38]."-->";         //echo "<!--".$this->block[39]." ".$this->block[40]."-->";         return(                ($this->block[37]==88  && //X 0x58                 $this->block[38]==105 && //i 0x69                 $this->block[39]==110 && //n 0x6E                 $this->block[40]==103)   //g 0x67 /*               ||                 ($this->block[21]==88  && //X 0x58                 $this->block[22]==105 && //i 0x69                 $this->block[23]==110 && //n 0x6E                 $this->block[24]==103)   //g 0x67*/               );        }      protected function debugbytes()     {         for($j=0; $j<10; $j++)         {             for($i=0; $i<8; $i++)             {                 if ($i==4) echo " ";                 echo $this->getnextbit();             }             echo "<BR>";         }     }     protected function prefetchblock()     {         $block = fread($this->fd, $this->blockmax);         $this->blocksize = strlen($block);         $this->block = unpack("C*", $block);         $this->blockpos=0;     }     protected function skipid3tag()     {         $bits=$this->getnextbits(24);//ID3         $bits.=$this->getnextbits(24);//v.v flags         //3 bytes 1 version byte 2 byte flags         $arr = array();         $arr['ID3v2 Major version'] = bindec(substr($bits,24,8));         $arr['ID3v2 Minor version'] = bindec(substr($bits,32,8));         $arr['ID3v2 flags'        ] = bindec(substr($bits,40,8));         if (substr($bits,40,1)) $arr['Unsynchronisation']=true;         if (substr($bits,41,1)) $arr['Extended header']=true;         if (substr($bits,42,1)) $arr['Experimental indicator']=true;         if (substr($bits,43,1)) $arr['Footer present']=true;         $size = "";         for($i=0; $i<4; $i++)         {             $this->getnextbit();//skip this bit, should be 0             $size.= $this->getnextbits(7);         }         $arr['ID3v2 Tags Size']=bindec($size);//now the size is in bytes;         if ($arr['ID3v2 Tags Size'] - $this->blockmax>0)         {             fseek($this->fd, $arr['ID3v2 Tags Size']+10 );             $this->prefetchblock();             if (isset($arr['Footer present']) && $arr['Footer present'])             {                 for($i=0; $i<10; $i++)                     $this->getnextbyte();//10 footer bytes             }         }         else         {             for($i=0; $i<$arr['ID3v2 Tags Size']; $i++)                 $this->getnextbyte();         }     }     protected function getnextbit()     {         if ($this->bitpos==8)             return false;         $b=0;         $whichbit = 7-$this->bitpos;         $mult = $this->powarr[$whichbit]; //$mult = pow(2,7-$this->pos);         $b = $this->block[$this->blockpos+1] & $mult;         $b = $b >> $whichbit;         $this->bitpos++;         if ($this->bitpos==8)         {             $this->blockpos++;                              if ($this->blockpos==$this->blockmax) //end of block reached             {                 $this->prefetchblock();             }             else if ($this->blockpos==$this->blocksize)              {//end of short block reached (shorter than blockmax)                 return;//eof              }                          $this->bitpos=0;         }         return $b;     }     protected function getnextbits($n=1)     {         $b="";         for($i=0; $i<$n; $i++)             $b.=$this->getnextbit();         return $b;     }     protected function getnextbyte()     {         if ($this->blockpos>=$this->blocksize)             return;         $this->bitpos=0;         $b=$this->block[$this->blockpos+1];         $this->blockpos++;         return $b;     }     //-----------------------------------------------------------------------------     public static function is_layer1(&$mp3) { return ($mp3['Layer Description']=='11'); }     public static function is_layer2(&$mp3) { return ($mp3['Layer Description']=='10'); }     public static function is_layer3(&$mp3) { return ($mp3['Layer Description']=='01'); }     public static function is_mpeg10(&$mp3)  { return ($mp3['MPEG version']=='11'); }     public static function is_mpeg20(&$mp3)  { return ($mp3['MPEG version']=='10'); }     public static function is_mpeg25(&$mp3)  { return ($mp3['MPEG version']=='00'); }     public static function is_mpeg20or25(&$mp3)  { return ($mp3['MPEG version']{1}=='0'); }     //-----------------------------------------------------------------------------     public static function bitratelookup(&$mp3)     {         //bits               V1,L1  V1,L2  V1,L3  V2,L1  V2,L2&L3         $array = array();         $array['0000']=array('free','free','free','free','free');         $array['0001']=array(  '32',  '32',  '32',  '32',   '8');         $array['0010']=array(  '64',  '48',  '40',  '48',  '16');         $array['0011']=array(  '96',  '56',  '48',  '56',  '24');         $array['0100']=array( '128',  '64',  '56',  '64',  '32');         $array['0101']=array( '160',  '80',  '64',  '80',  '40');         $array['0110']=array( '192',  '96',  '80',  '96',  '48');         $array['0111']=array( '224', '112',  '96', '112',  '56');         $array['1000']=array( '256', '128', '112', '128',  '64');         $array['1001']=array( '288', '160', '128', '144',  '80');         $array['1010']=array( '320', '192', '160', '160',  '96');         $array['1011']=array( '352', '224', '192', '176', '112');         $array['1100']=array( '384', '256', '224', '192', '128');         $array['1101']=array( '416', '320', '256', '224', '144');         $array['1110']=array( '448', '384', '320', '256', '160');         $array['1111']=array( 'bad', 'bad', 'bad', 'bad', 'bad');                  $whichcolumn=-1;         if      (mp3file::is_mpeg10($mp3) && mp3file::is_layer1($mp3) )//V1,L1             $whichcolumn=0;         else if (mp3file::is_mpeg10($mp3) && mp3file::is_layer2($mp3) )//V1,L2             $whichcolumn=1;         else if (mp3file::is_mpeg10($mp3) && mp3file::is_layer3($mp3) )//V1,L3             $whichcolumn=2;         else if (mp3file::is_mpeg20or25($mp3) && mp3file::is_layer1($mp3) )//V2,L1             $whichcolumn=3;         else if (mp3file::is_mpeg20or25($mp3) && (mp3file::is_layer2($mp3) || mp3file::is_layer3($mp3)) )             $whichcolumn=4;//V2,   L2||L3                   if (isset($array[$mp3['Bitrate Index']][$whichcolumn]))             return $array[$mp3['Bitrate Index']][$whichcolumn];         else              return "bad";     }     //-----------------------------------------------------------------------------     public static function samplelookup(&$mp3)     {         //bits               MPEG1   MPEG2   MPEG2.5         $array = array();         $array['00'] =array('44100','22050','11025');         $array['01'] =array('48000','24000','12000');         $array['10'] =array('32000','16000','8000');         $array['11'] =array('res','res','res');                  $whichcolumn=-1;         if      (mp3file::is_mpeg10($mp3))             $whichcolumn=0;         else if (mp3file::is_mpeg20($mp3))             $whichcolumn=1;         else if (mp3file::is_mpeg25($mp3))             $whichcolumn=2;                  if (isset($array[$mp3['Sampling Freq Idx']][$whichcolumn]))             return $array[$mp3['Sampling Freq Idx']][$whichcolumn];         else              return 'unknown';     }     //-----------------------------------------------------------------------------     public static function getframesize(&$mp3)     {         if ($mp3['Sampling Rate']>0)         {             return  ceil((144 * $mp3['Bitrate']*1000)/$mp3['Sampling Rate']) + $mp3['Padding Bit'];         }         return 'unknown';     }     //-----------------------------------------------------------------------------     public static function getduration(&$mp3,$startat)     {         if ($mp3['Bitrate']>0)         {             $KBps = ($mp3['Bitrate']*1000)/8;             $datasize = ($mp3['Filesize'] - ($startat/8));             $length = $datasize / $KBps;             return sprintf("%d", $length);         }         return "unknown";     }     //-----------------------------------------------------------------------------     public static function seconds_to_mmss($duration)     {         return sprintf("%d:%02d", ($duration /60), $duration %60 );     } }

调用

<?php include_once 'mp3file.class.php'; function mp3Time($file) {    $m = new mp3file($file);    $a = $m->get_metadata();    return $a['Length mm:ss'] ? $a['Length mm:ss'] : 0; } function mp3Info($file) {    $m = new mp3file($file);    return $m->get_metadata(); } $_time = mp3Time('Beyond-情人.mp3'); echo "歌曲时间长：{$_time}\n"; $_info = mp3Info('Beyond-情人.mp3'); print_r($_info);

输出信息

→ php mp3.php 歌曲时间长：5:15 Array (     [Filesize] => 7576152     [Encoding] => CBR     [MPEG version] => 11     [Layer Description] => 01     [Protection Bit] => 1     [Bitrate Index] => 1011     [Sampling Freq Idx] => 00     [Padding Bit] => 0     [Private Bit] => 0     [Channel Mode] => 00     [Mode Extension] => 00     [Copyright] => 0     [Original Media] => 1     [Emphasis] => 0     [Bitrate] => 192     [Sampling Rate] => 44100     [Frame Size] => 627     [Length] => 315     [Length mm:ss] => 5:15 )

推荐教程：《php视频教程》

以上就是php获取mp3音频信息实例教程的详细内容，更多内容请关注技术你好其它相关文章！