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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

<?phpclass 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

<?phpinclude_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:5:15Array(    [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》

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文章来源:智云一二三科技

文章标题:php获取mp3音频信息实例教程

文章地址:https://www.zhihuclub.com/7101.shtml

关于作者: 智云科技

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