mbirth/php-mp3info
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This commit is contained in:
wapmorgan 2018-12-15 00:03:35 +03:00
parent 9d5d136e1b
commit 491bee5706
1 changed files with 33 additions and 9 deletions
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42
src/Mp3Info.php
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@ -27,21 +27,27 @@ class Mp3Info {
const VBR_SYNC = 'Xing';
const CBR_SYNC = 'Info';
/**
* Magic constants
*/
const FRAME_SYNC = 0xffe0;
const LAYER_1_FRAME_SIZE = 384;
const LAYERS_23_FRAME_SIZE = 1152;
const META = 1;
const TAGS = 2;
const MPEG_1 = 1;
const MPEG_2 = 2;
const MPEG_2 = 2;
const LAYER_1 = 1;
const LAYER_2 = 2;
const LAYER_3 = 3;
const LAYER_3 = 3;
const STEREO = 'stereo';
const JOINT_STEREO = 'joint_stereo';
const DUAL_MONO = 'dual_mono';
const MONO = 'mono';
/**
@ -52,22 +58,22 @@ class Mp3Info {
* @var array
*/
static private $_bitRateTable;
/**
* @var array
*/
static private $_sampleRateTable;
/**
* MPEG codec version (1 or 2)
* @var int
*/
public $codecVersion;
/**
* Audio layer version (1 or 2 or 3)
* @var int
*/
public $layerVersion;
/**
* Audio size in bytes. Note that this value is NOT equals file size.
* @var int
@ -147,6 +153,7 @@ class Mp3Info {
* @var array
*/
public $id3v2TagsFlags = array();
/**
* Contains time spent to read&extract audio information.
* @var float
@ -174,7 +181,7 @@ class Mp3Info {
self::$_sampleRateTable = require dirname(__FILE__).'/../data/sampleRateTable.php';
if (!file_exists($filename))
throw new \Exception("File ".$filename." is not present!");
throw new \Exception('File '.$filename.' is not present!');
$mode = $parseTags ? self::META | self::TAGS : self::META;
$this->audioSize = $this->parseAudio($this->_fileName = $filename, $this->_fileSize = filesize($filename), $mode);
}
@ -223,9 +230,15 @@ class Mp3Info {
// audio meta
if ($mode & self::META) {
if (isset($id3v2Size)) fseek($fp, $id3v2Size);
/**
* First frame can lie. Need to fix in future.
* @link https://github.com/wapmorgan/Mp3Info/issues/13#issuecomment-447470813
*/
$framesCount = $this->readFirstFrame($fp);
if (!is_null($framesCount)) $this->framesCount = $framesCount;
else $this->framesCount = ceil($audioSize / $this->__cbrFrameSize);
$this->framesCount = $framesCount !== null
? $framesCount
: ceil($audioSize / $this->__cbrFrameSize);
// recalculate average bit rate in vbr case
if ($this->isVbr && !is_null($framesCount)) {
@ -233,7 +246,11 @@ class Mp3Info {
$this->bitRate = $avgFrameSize * $this->sampleRate / (1000 * $this->layerVersion == 3 ? 12 : 144);
}
$this->duration = ($this->framesCount - 1) * ($this->layerVersion == 1 ? 384 : 1152) / $this->sampleRate;
// The faster way to detect audio duration:
// Calculate total number of audio samples (framesCount * sampleInFrameCount) / samplesInSecondCount
$this->duration = ($this->framesCount - 1)
* ($this->layerVersion == 1 ? self::LAYER_1_FRAME_SIZE : self::LAYERS_23_FRAME_SIZE)
/ $this->sampleRate;
}
fclose($fp);
@ -314,6 +331,13 @@ class Mp3Info {
return isset($framesCount) ? $framesCount : null;
}
/**
* @param $fp
* @param $n
*
* @return array
* @throws \Exception
*/
private function readBytes($fp, $n) {
$raw = fread($fp, $n);
if (strlen($raw) !== $n) throw new \Exception('Unexpected end of file!');