Php 获取音频文件的长度

如何在php中获取音频文件的长度

---

如果用php做起来太难，那么任何其他方法都可以。什么样的音频文件？mp3？wav？ 无论如何，您可能需要一些特定的库。

---

请参阅：

PHP没有标准音频支持，您必须自己重新编译PHP，或者您可以使用工具获取信息：

你可以使用ffmpeg。按如下方式运行ffmpeg：

ffmpeg -i someAudio.mp3

将产生以下输出：

Input #0, mp3, from 'someAudio.mp3':
  Duration: 00:00:34.03, start: 0.000000, bitrate: 127 kb/s
    Stream #0.0: Audio: mp3, 48000 Hz, mono, s16, 128 kb/s

现在只需要一个ReXEP来解析结果。

是一个你可以考虑的第三方应用程序。

LAME是根据LGPL许可的高质量MPEG音频第三层（MP3）编码器

---

如果您正在使用linux/unix并安装了ffmpeg，只需执行以下操作：

$time = exec("ffmpeg -i " . escapeshellarg($path) . " 2>&1 | grep 'Duration' | cut -d ' ' -f 4 | sed s/,//");
list($hms, $milli) = explode('.', $time);
list($hours, $minutes, $seconds) = explode(':', $hms);
$total_seconds = ($hours * 3600) + ($minutes * 60) + $seconds;

---

如果你处理的是wave文件，你只需要将wave采样长度除以采样率，就可以在几秒钟内得到音频的长度。

如果你/某人想测量mp3的持续时间，我找到了一些代码，效果很好，不需要扩展名

ctrl+v

<?php
$mp3file = new MP3File("npr_304314290.mp3");//http://www.npr.org/rss/podcast.php?id=510282
$duration1 = $mp3file->getDurationEstimate();//(faster) for CBR only
$duration2 = $mp3file->getDuration();//(slower) for VBR (or CBR)
echo "duration: $duration1 seconds"."\n";
echo "estimate: $duration2 seconds"."\n";
echo MP3File::formatTime($duration2)."\n";
?>

类别：

<?php
class MP3File
{
protected $filename;
public function __construct($filename)
{
    $this->filename = $filename;
}

public static function formatTime($duration) //as hh:mm:ss
{
    //return sprintf("%d:%02d", $duration/60, $duration%60);
    $hours = floor($duration / 3600);
    $minutes = floor( ($duration - ($hours * 3600)) / 60);
    $seconds = $duration - ($hours * 3600) - ($minutes * 60);
    return sprintf("%02d:%02d:%02d", $hours, $minutes, $seconds);
}

//Read first mp3 frame only...  use for CBR constant bit rate MP3s
public function getDurationEstimate()
{
    return $this->getDuration($use_cbr_estimate=true);
}

//Read entire file, frame by frame... ie: Variable Bit Rate (VBR)
public function getDuration($use_cbr_estimate=false)
{
    $fd = fopen($this->filename, "rb");

    $duration=0;
    $block = fread($fd, 100);
    $offset = $this->skipID3v2Tag($block);
    fseek($fd, $offset, SEEK_SET);
    while (!feof($fd))
    {
        $block = fread($fd, 10);
        if (strlen($block)<10) { break; }
        //looking for 1111 1111 111 (frame synchronization bits)
        else if ($block[0]=="\xff" && (ord($block[1])&0xe0) )
        {
            $info = self::parseFrameHeader(substr($block, 0, 4));
            if (empty($info['Framesize'])) { return $duration; } //some corrupt mp3 files
            fseek($fd, $info['Framesize']-10, SEEK_CUR);
            $duration += ( $info['Samples'] / $info['Sampling Rate'] );
        }
        else if (substr($block, 0, 3)=='TAG')
        {
            fseek($fd, 128-10, SEEK_CUR);//skip over id3v1 tag size
        }
        else
        {
            fseek($fd, -9, SEEK_CUR);
        }
        if ($use_cbr_estimate && !empty($info))
        { 
            return $this->estimateDuration($info['Bitrate'],$offset); 
        }
    }
    return round($duration);
}

private function estimateDuration($bitrate,$offset)
{
    $kbps = ($bitrate*1000)/8;
    $datasize = filesize($this->filename) - $offset;
    return round($datasize / $kbps);
}

private function skipID3v2Tag(&$block)
{
    if (substr($block, 0,3)=="ID3")
    {
        $id3v2_major_version = ord($block[3]);
        $id3v2_minor_version = ord($block[4]);
        $id3v2_flags = ord($block[5]);
        $flag_unsynchronisation  = $id3v2_flags & 0x80 ? 1 : 0;
        $flag_extended_header    = $id3v2_flags & 0x40 ? 1 : 0;
        $flag_experimental_ind   = $id3v2_flags & 0x20 ? 1 : 0;
        $flag_footer_present     = $id3v2_flags & 0x10 ? 1 : 0;
        $z0 = ord($block[6]);
        $z1 = ord($block[7]);
        $z2 = ord($block[8]);
        $z3 = ord($block[9]);
        if ( (($z0&0x80)==0) && (($z1&0x80)==0) && (($z2&0x80)==0) && (($z3&0x80)==0) )
        {
            $header_size = 10;
            $tag_size = (($z0&0x7f) * 2097152) + (($z1&0x7f) * 16384) + (($z2&0x7f) * 128) + ($z3&0x7f);
            $footer_size = $flag_footer_present ? 10 : 0;
            return $header_size + $tag_size + $footer_size;//bytes to skip
        }
    }
    return 0;
}

public static function parseFrameHeader($fourbytes)
{
    static $versions = array(
        0x0=>'2.5',0x1=>'x',0x2=>'2',0x3=>'1', // x=>'reserved'
    );
    static $layers = array(
        0x0=>'x',0x1=>'3',0x2=>'2',0x3=>'1', // x=>'reserved'
    );
    static $bitrates = array(
        'V1L1'=>array(0,32,64,96,128,160,192,224,256,288,320,352,384,416,448),
        'V1L2'=>array(0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384),
        'V1L3'=>array(0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320),
        'V2L1'=>array(0,32,48,56, 64, 80, 96,112,128,144,160,176,192,224,256),
        'V2L2'=>array(0, 8,16,24, 32, 40, 48, 56, 64, 80, 96,112,128,144,160),
        'V2L3'=>array(0, 8,16,24, 32, 40, 48, 56, 64, 80, 96,112,128,144,160),
    );
    static $sample_rates = array(
        '1'   => array(44100,48000,32000),
        '2'   => array(22050,24000,16000),
        '2.5' => array(11025,12000, 8000),
    );
    static $samples = array(
        1 => array( 1 => 384, 2 =>1152, 3 =>1152, ), //MPEGv1,     Layers 1,2,3
        2 => array( 1 => 384, 2 =>1152, 3 => 576, ), //MPEGv2/2.5, Layers 1,2,3
    );
    //$b0=ord($fourbytes[0]);//will always be 0xff
    $b1=ord($fourbytes[1]);
    $b2=ord($fourbytes[2]);
    $b3=ord($fourbytes[3]);

    $version_bits = ($b1 & 0x18) >> 3;
    $version = $versions[$version_bits];
    $simple_version =  ($version=='2.5' ? 2 : $version);

    $layer_bits = ($b1 & 0x06) >> 1;
    $layer = $layers[$layer_bits];

    $protection_bit = ($b1 & 0x01);
    $bitrate_key = sprintf('V%dL%d', $simple_version , $layer);
    $bitrate_idx = ($b2 & 0xf0) >> 4;
    $bitrate = isset($bitrates[$bitrate_key][$bitrate_idx]) ? $bitrates[$bitrate_key][$bitrate_idx] : 0;

    $sample_rate_idx = ($b2 & 0x0c) >> 2;//0xc => b1100
    $sample_rate = isset($sample_rates[$version][$sample_rate_idx]) ? $sample_rates[$version][$sample_rate_idx] : 0;
    $padding_bit = ($b2 & 0x02) >> 1;
    $private_bit = ($b2 & 0x01);
    $channel_mode_bits = ($b3 & 0xc0) >> 6;
    $mode_extension_bits = ($b3 & 0x30) >> 4;
    $copyright_bit = ($b3 & 0x08) >> 3;
    $original_bit = ($b3 & 0x04) >> 2;
    $emphasis = ($b3 & 0x03);

    $info = array();
    $info['Version'] = $version;//MPEGVersion
    $info['Layer'] = $layer;
    //$info['Protection Bit'] = $protection_bit; //0=> protected by 2 byte CRC, 1=>not protected
    $info['Bitrate'] = $bitrate;
    $info['Sampling Rate'] = $sample_rate;
    //$info['Padding Bit'] = $padding_bit;
    //$info['Private Bit'] = $private_bit;
    //$info['Channel Mode'] = $channel_mode_bits;
    //$info['Mode Extension'] = $mode_extension_bits;
    //$info['Copyright'] = $copyright_bit;
    //$info['Original'] = $original_bit;
    //$info['Emphasis'] = $emphasis;
    $info['Framesize'] = self::framesize($layer, $bitrate, $sample_rate, $padding_bit);
    $info['Samples'] = $samples[$simple_version][$layer];
    return $info;
}

private static function framesize($layer, $bitrate,$sample_rate,$padding_bit)
{
    if ($layer==1)
        return intval(((12 * $bitrate*1000 /$sample_rate) + $padding_bit) * 4);
    else //layer 2, 3
        return intval(((144 * $bitrate*1000)/$sample_rate) + $padding_bit);
}
}

对Stephen Fuhry答案的改进：
谢谢你，斯蒂芬！这对我来说效果很好（尽管对于数百个文件来说速度很慢）.
2020年更新：有许多PHP软件包可以处理音频/视频文件并检测它们的持续时间：大多数都要求在开发/生产环境中安装ffmpeg。
任何音频格式或精确格式？ffmpeg都将被取消，因此应改为exec（“avconv-i”。escapeshellarg（$path）。“2>&1 | grep'Duration'| cut-d'-f 4 | sed s/，/”
ffmpeg-i someAudio.mp3
不会生成您描述的输出，因为应该在ffmpeg命令中指定一个输出文件。它正在生成错误
必须至少指定一个输出文件
/**
 * https://stackoverflow.com/a/7135484/470749
 * @param string $path
 * @return int
 */
function getDurationOfWavInMs($path) {
    $time = getDurationOfWav($path);
    list($hms, $milli) = explode('.', $time);
    list($hours, $minutes, $seconds) = explode(':', $hms);
    $totalSeconds = ($hours * 3600) + ($minutes * 60) + $seconds;
    return ($totalSeconds * 1000) + $milli;
}

/**
 * 
 * @param string $path
 * @return string
 */
function getDurationOfWav($path) {
    $cmd = "ffmpeg -i " . escapeshellarg($path) . " 2>&1 | grep 'Duration' | cut -d ' ' -f 4 | sed s/,//";
    return exec($cmd);
}