* File: WavFile.php
*
* Copyright (c) 2012, Drew Phillips
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Any modifications to the library should be indicated clearly in the source code
* to inform users that the changes are not a part of the original software.
*
* @copyright 2012 Drew Phillips
* @author Drew Phillips
* @author Paul Voegler
* @version 1.0 (October 2012)
* @package PHPWavUtils
* @license BSD License
*
* Changelog:
*
* 1.0 (10/2/2012)
* - Fix insertSilence() creating invalid block size
*
* 1.0 RC1 (4/20/2012)
* - Initial release candidate
* - Supports 8, 16, 24, 32 bit PCM, 32-bit IEEE FLOAT, Extensible Format
* - Support for 18 channels of audio
* - Ability to read an offset from a file to reduce memory footprint with large files
* - Single-pass audio filter processing
* - Highly accurate and efficient mix and normalization filters (http://www.voegler.eu/pub/audio/)
* - Utility filters for degrading audio, and inserting silence
*
* 0.6 (4/12/2012)
* - Support 8, 16, 24, 32 bit and PCM float (Paul Voegler)
* - Add normalize filter, misc improvements and fixes (Paul Voegler)
* - Normalize parameters to filter() to use filter constants as array indices
* - Add option to mix filter to loop the target file if the source is longer
*
* 0.5 (4/3/2012)
* - Fix binary pack routine (Paul Voegler)
* - Add improved mixing function (Paul Voegler)
*
*/
class WavFile
{
/*%******************************************************************************************%*/
// Class constants
/** @var int Filter flag for mixing two files */
const FILTER_MIX = 0x01;
/** @var int Filter flag for normalizing audio data */
const FILTER_NORMALIZE = 0x02;
/** @var int Filter flag for degrading audio data */
const FILTER_DEGRADE = 0x04;
/** @var int Maximum number of channels */
const MAX_CHANNEL = 18;
/** @var int Maximum sample rate */
const MAX_SAMPLERATE = 192000;
/** Channel Locations for ChannelMask */
const SPEAKER_DEFAULT = 0x000000;
const SPEAKER_FRONT_LEFT = 0x000001;
const SPEAKER_FRONT_RIGHT = 0x000002;
const SPEAKER_FRONT_CENTER = 0x000004;
const SPEAKER_LOW_FREQUENCY = 0x000008;
const SPEAKER_BACK_LEFT = 0x000010;
const SPEAKER_BACK_RIGHT = 0x000020;
const SPEAKER_FRONT_LEFT_OF_CENTER = 0x000040;
const SPEAKER_FRONT_RIGHT_OF_CENTER = 0x000080;
const SPEAKER_BACK_CENTER = 0x000100;
const SPEAKER_SIDE_LEFT = 0x000200;
const SPEAKER_SIDE_RIGHT = 0x000400;
const SPEAKER_TOP_CENTER = 0x000800;
const SPEAKER_TOP_FRONT_LEFT = 0x001000;
const SPEAKER_TOP_FRONT_CENTER = 0x002000;
const SPEAKER_TOP_FRONT_RIGHT = 0x004000;
const SPEAKER_TOP_BACK_LEFT = 0x008000;
const SPEAKER_TOP_BACK_CENTER = 0x010000;
const SPEAKER_TOP_BACK_RIGHT = 0x020000;
const SPEAKER_ALL = 0x03FFFF;
/** @var int PCM Audio Format */
const WAVE_FORMAT_PCM = 0x0001;
/** @var int IEEE FLOAT Audio Format */
const WAVE_FORMAT_IEEE_FLOAT = 0x0003;
/** @var int EXTENSIBLE Audio Format - actual audio format defined by SubFormat */
const WAVE_FORMAT_EXTENSIBLE = 0xFFFE;
/** @var string PCM Audio Format SubType - LE hex representation of GUID {00000001-0000-0010-8000-00AA00389B71} */
const WAVE_SUBFORMAT_PCM = "0100000000001000800000aa00389b71";
/** @var string IEEE FLOAT Audio Format SubType - LE hex representation of GUID {00000003-0000-0010-8000-00AA00389B71} */
const WAVE_SUBFORMAT_IEEE_FLOAT = "0300000000001000800000aa00389b71";
/*%******************************************************************************************%*/
// Properties
/** @var array Log base modifier lookup table for a given threshold (in 0.05 steps) used by normalizeSample.
* Adjusts the slope (1st derivative) of the log function at the threshold to 1 for a smooth transition
* from linear to logarithmic amplitude output. */
protected static $LOOKUP_LOGBASE = array(
2.513, 2.667, 2.841, 3.038, 3.262,
3.520, 3.819, 4.171, 4.589, 5.093,
5.711, 6.487, 7.483, 8.806, 10.634,
13.302, 17.510, 24.970, 41.155, 96.088
);
/** @var int The actual physical file size */
protected $_actualSize;
/** @var int The size of the file in RIFF header */
protected $_chunkSize;
/** @var int The size of the "fmt " chunk */
protected $_fmtChunkSize;
/** @var int The size of the extended "fmt " data */
protected $_fmtExtendedSize;
/** @var int The size of the "fact" chunk */
protected $_factChunkSize;
/** @var int Size of the data chunk */
protected $_dataSize;
/** @var int Size of the data chunk in the opened wav file */
protected $_dataSize_fp;
/** @var int Does _dataSize really reflect strlen($_samples)? Case when a wav file is read with readData = false */
protected $_dataSize_valid;
/** @var int Starting offset of data chunk */
protected $_dataOffset;
/** @var int The audio format - WavFile::WAVE_FORMAT_* */
protected $_audioFormat;
/** @var int The audio subformat - WavFile::WAVE_SUBFORMAT_* */
protected $_audioSubFormat;
/** @var int Number of channels in the audio file */
protected $_numChannels;
/** @var int The channel mask */
protected $_channelMask;
/** @var int Samples per second */
protected $_sampleRate;
/** @var int Number of bits per sample */
protected $_bitsPerSample;
/** @var int Number of valid bits per sample */
protected $_validBitsPerSample;
/** @var int NumChannels * BitsPerSample/8 */
protected $_blockAlign;
/** @var int Number of sample blocks */
protected $_numBlocks;
/** @var int Bytes per second */
protected $_byteRate;
/** @var string Binary string of samples */
protected $_samples;
/** @var resource The file pointer used for reading wavs from file or memory */
protected $_fp;
/*%******************************************************************************************%*/
// Special methods
/**
* WavFile Constructor.
*
*
* $wav1 = new WavFile(2, 44100, 16); // new wav with 2 channels, at 44100 samples/sec and 16 bits per sample
* $wav2 = new WavFile('./audio/sound.wav'); // open and read wav file
*
*
* @param string|int $numChannelsOrFileName (Optional) If string, the filename of the wav file to open. The number of channels otherwise. Defaults to 1.
* @param int|bool $sampleRateOrReadData (Optional) If opening a file and boolean, decides whether to read the data chunk or not. Defaults to true. The sample rate in samples per second otherwise. 8000 = standard telephone, 16000 = wideband telephone, 32000 = FM radio and 44100 = CD quality. Defaults to 8000.
* @param int $bitsPerSample (Optional) The number of bits per sample. Has to be 8, 16 or 24 for PCM audio or 32 for IEEE FLOAT audio. 8 = telephone, 16 = CD and 24 or 32 = studio quality. Defaults to 8.
* @throws WavFormatException
* @throws WavFileException
*/
public function __construct($numChannelsOrFileName = null, $sampleRateOrReadData = null, $bitsPerSample = null)
{
$this->_actualSize = 44;
$this->_chunkSize = 36;
$this->_fmtChunkSize = 16;
$this->_fmtExtendedSize = 0;
$this->_factChunkSize = 0;
$this->_dataSize = 0;
$this->_dataSize_fp = 0;
$this->_dataSize_valid = true;
$this->_dataOffset = 44;
$this->_audioFormat = self::WAVE_FORMAT_PCM;
$this->_audioSubFormat = null;
$this->_numChannels = 1;
$this->_channelMask = self::SPEAKER_DEFAULT;
$this->_sampleRate = 8000;
$this->_bitsPerSample = 8;
$this->_validBitsPerSample = 8;
$this->_blockAlign = 1;
$this->_numBlocks = 0;
$this->_byteRate = 8000;
$this->_samples = '';
$this->_fp = null;
if (is_string($numChannelsOrFileName)) {
$this->openWav($numChannelsOrFileName, is_bool($sampleRateOrReadData) ? $sampleRateOrReadData : true);
} else {
$this->setNumChannels(is_null($numChannelsOrFileName) ? 1 : $numChannelsOrFileName)
->setSampleRate(is_null($sampleRateOrReadData) ? 8000 : $sampleRateOrReadData)
->setBitsPerSample(is_null($bitsPerSample) ? 8 : $bitsPerSample);
}
}
public function __destruct() {
if (is_resource($this->_fp)) $this->closeWav();
}
public function __clone() {
$this->_fp = null;
}
/**
* Output the wav file headers and data.
*
* @return string The encoded file.
*/
public function __toString()
{
return $this->makeHeader() .
$this->getDataSubchunk();
}
/*%******************************************************************************************%*/
// Static methods
/**
* Unpacks a single binary sample to numeric value.
*
* @param string $sampleBinary (Required) The sample to decode.
* @param int $bitDepth (Optional) The bits per sample to decode. If omitted, derives it from the length of $sampleBinary.
* @return int|float The numeric sample value. Float for 32-bit samples. Returns null for unsupported bit depths.
*/
public static function unpackSample($sampleBinary, $bitDepth = null)
{
if ($bitDepth === null) {
$bitDepth = strlen($sampleBinary) * 8;
}
switch ($bitDepth) {
case 8:
// unsigned char
return ord($sampleBinary);
case 16:
// signed short, little endian
$data = unpack('v', $sampleBinary);
$sample = $data[1];
if ($sample >= 0x8000) {
$sample -= 0x10000;
}
return $sample;
case 24:
// 3 byte packed signed integer, little endian
$data = unpack('C3', $sampleBinary);
$sample = $data[1] | ($data[2] << 8) | ($data[3] << 16);
if ($sample >= 0x800000) {
$sample -= 0x1000000;
}
return $sample;
case 32:
// 32-bit float
$data = unpack('f', $sampleBinary);
return $data[1];
default:
return null;
}
}
/**
* Packs a single numeric sample to binary.
*
* @param int|float $sample (Required) The sample to encode. Has to be within valid range for $bitDepth. Float values only for 32 bits.
* @param int $bitDepth (Required) The bits per sample to encode with.
* @return string The encoded binary sample. Returns null for unsupported bit depths.
*/
public static function packSample($sample, $bitDepth)
{
switch ($bitDepth) {
case 8:
// unsigned char
return chr($sample);
case 16:
// signed short, little endian
if ($sample < 0) {
$sample += 0x10000;
}
return pack('v', $sample);
case 24:
// 3 byte packed signed integer, little endian
if ($sample < 0) {
$sample += 0x1000000;
}
return pack('C3', $sample & 0xff, ($sample >> 8) & 0xff, ($sample >> 16) & 0xff);
case 32:
// 32-bit float
return pack('f', $sample);
default:
return null;
}
}
/**
* Unpacks a binary sample block to numeric values.
*
* @param string $sampleBlock (Required) The binary sample block (all channels).
* @param int $bitDepth (Required) The bits per sample to decode.
* @param int $numChannels (Optional) The number of channels to decode. If omitted, derives it from the length of $sampleBlock and $bitDepth.
* @return array The sample values as an array of integers of floats for 32 bits. First channel is array index 1.
*/
public static function unpackSampleBlock($sampleBlock, $bitDepth, $numChannels = null) {
$sampleBytes = $bitDepth / 8;
if ($numChannels === null) {
$numChannels = strlen($sampleBlock) / $sampleBytes;
}
$samples = array();
for ($i = 0; $i < $numChannels; $i++) {
$sampleBinary = substr($sampleBlock, $i * $sampleBytes, $sampleBytes);
$samples[$i + 1] = self::unpackSample($sampleBinary, $bitDepth);
}
return $samples;
}
/**
* Packs an array of numeric channel samples to a binary sample block.
*
* @param array $samples (Required) The array of channel sample values. Expects float values for 32 bits and integer otherwise.
* @param int $bitDepth (Required) The bits per sample to encode with.
* @return string The encoded binary sample block.
*/
public static function packSampleBlock($samples, $bitDepth) {
$sampleBlock = '';
foreach($samples as $sample) {
$sampleBlock .= self::packSample($sample, $bitDepth);
}
return $sampleBlock;
}
/**
* Normalizes a float audio sample. Maximum input range assumed for compression is [-2, 2].
* See http://www.voegler.eu/pub/audio/ for more information.
*
* @param float $sampleFloat (Required) The float sample to normalize.
* @param float $threshold (Required) The threshold or gain factor for normalizing the amplitude.
* - >= 1 - Normalize by multiplying by the threshold (boost - positive gain).
* A value of 1 in effect means no normalization (and results in clipping).
* - <= -1 - Normalize by dividing by the the absolute value of threshold (attenuate - negative gain).
* A factor of 2 (-2) is about 6dB reduction in volume.
* - [0, 1) - (open inverval - not including 1) - The threshold
* above which amplitudes are comressed logarithmically.
* e.g. 0.6 to leave amplitudes up to 60% "as is" and compress above.
* - (-1, 0) - (open inverval - not including -1 and 0) - The threshold
* above which amplitudes are comressed linearly.
* e.g. -0.6 to leave amplitudes up to 60% "as is" and compress above.
* @return float The normalized sample.
**/
public static function normalizeSample($sampleFloat, $threshold) {
// apply positive gain
if ($threshold >= 1) {
return $sampleFloat * $threshold;
}
// apply negative gain
if ($threshold <= -1) {
return $sampleFloat / -$threshold;
}
$sign = $sampleFloat < 0 ? -1 : 1;
$sampleAbs = abs($sampleFloat);
// logarithmic compression
if ($threshold >= 0 && $threshold < 1 && $sampleAbs > $threshold) {
$loga = self::$LOOKUP_LOGBASE[(int)($threshold * 20)]; // log base modifier
return $sign * ($threshold + (1 - $threshold) * log(1 + $loga * ($sampleAbs - $threshold) / (2 - $threshold)) / log(1 + $loga));
}
// linear compression
$thresholdAbs = abs($threshold);
if ($threshold > -1 && $threshold < 0 && $sampleAbs > $thresholdAbs) {
return $sign * ($thresholdAbs + (1 - $thresholdAbs) / (2 - $thresholdAbs) * ($sampleAbs - $thresholdAbs));
}
// else ?
return $sampleFloat;
}
/*%******************************************************************************************%*/
// Getter and Setter methods for properties
public function getActualSize() {
return $this->_actualSize;
}
protected function setActualSize($actualSize = null) {
if (is_null($actualSize)) {
$this->_actualSize = 8 + $this->_chunkSize; // + "RIFF" header (ID + size)
} else {
$this->_actualSize = $actualSize;
}
return $this;
}
public function getChunkSize() {
return $this->_chunkSize;
}
protected function setChunkSize($chunkSize = null) {
if (is_null($chunkSize)) {
$this->_chunkSize = 4 + // "WAVE" chunk
8 + $this->_fmtChunkSize + // "fmt " subchunk
($this->_factChunkSize > 0 ? 8 + $this->_factChunkSize : 0) + // "fact" subchunk
8 + $this->_dataSize + // "data" subchunk
($this->_dataSize & 1); // padding byte
} else {
$this->_chunkSize = $chunkSize;
}
$this->setActualSize();
return $this;
}
public function getFmtChunkSize() {
return $this->_fmtChunkSize;
}
protected function setFmtChunkSize($fmtChunkSize = null) {
if (is_null($fmtChunkSize)) {
$this->_fmtChunkSize = 16 + $this->_fmtExtendedSize;
} else {
$this->_fmtChunkSize = $fmtChunkSize;
}
$this->setChunkSize() // implicit setActualSize()
->setDataOffset();
return $this;
}
public function getFmtExtendedSize() {
return $this->_fmtExtendedSize;
}
protected function setFmtExtendedSize($fmtExtendedSize = null) {
if (is_null($fmtExtendedSize)) {
if ($this->_audioFormat == self::WAVE_FORMAT_EXTENSIBLE) {
$this->_fmtExtendedSize = 2 + 22; // extension size for WAVE_FORMAT_EXTENSIBLE
} elseif ($this->_audioFormat != self::WAVE_FORMAT_PCM) {
$this->_fmtExtendedSize = 2 + 0; // empty extension
} else {
$this->_fmtExtendedSize = 0; // no extension, only for WAVE_FORMAT_PCM
}
} else {
$this->_fmtExtendedSize = $fmtExtendedSize;
}
$this->setFmtChunkSize(); // implicit setSize(), setActualSize(), setDataOffset()
return $this;
}
public function getFactChunkSize() {
return $this->_factChunkSize;
}
protected function setFactChunkSize($factChunkSize = null) {
if (is_null($factChunkSize)) {
if ($this->_audioFormat != self::WAVE_FORMAT_PCM) {
$this->_factChunkSize = 4;
} else {
$this->_factChunkSize = 0;
}
} else {
$this->_factChunkSize = $factChunkSize;
}
$this->setChunkSize() // implicit setActualSize()
->setDataOffset();
return $this;
}
public function getDataSize() {
return $this->_dataSize;
}
protected function setDataSize($dataSize = null) {
if (is_null($dataSize)) {
$this->_dataSize = strlen($this->_samples);
} else {
$this->_dataSize = $dataSize;
}
$this->setChunkSize() // implicit setActualSize()
->setNumBlocks();
$this->_dataSize_valid = true;
return $this;
}
public function getDataOffset() {
return $this->_dataOffset;
}
protected function setDataOffset($dataOffset = null) {
if (is_null($dataOffset)) {
$this->_dataOffset = 8 + // "RIFF" header (ID + size)
4 + // "WAVE" chunk
8 + $this->_fmtChunkSize + // "fmt " subchunk
($this->_factChunkSize > 0 ? 8 + $this->_factChunkSize : 0) + // "fact" subchunk
8; // "data" subchunk
} else {
$this->_dataOffset = $dataOffset;
}
return $this;
}
public function getAudioFormat() {
return $this->_audioFormat;
}
protected function setAudioFormat($audioFormat = null) {
if (is_null($audioFormat)) {
if (($this->_bitsPerSample <= 16 || $this->_bitsPerSample == 32)
&& $this->_validBitsPerSample == $this->_bitsPerSample
&& $this->_channelMask == self::SPEAKER_DEFAULT
&& $this->_numChannels <= 2) {
if ($this->_bitsPerSample <= 16) {
$this->_audioFormat = self::WAVE_FORMAT_PCM;
} else {
$this->_audioFormat = self::WAVE_FORMAT_IEEE_FLOAT;
}
} else {
$this->_audioFormat = self::WAVE_FORMAT_EXTENSIBLE;
}
} else {
$this->_audioFormat = $audioFormat;
}
$this->setAudioSubFormat()
->setFactChunkSize() // implicit setSize(), setActualSize(), setDataOffset()
->setFmtExtendedSize(); // implicit setFmtChunkSize(), setSize(), setActualSize(), setDataOffset()
return $this;
}
public function getAudioSubFormat() {
return $this->_audioSubFormat;
}
protected function setAudioSubFormat($audioSubFormat = null) {
if (is_null($audioSubFormat)) {
if ($this->_bitsPerSample == 32) {
$this->_audioSubFormat = self::WAVE_SUBFORMAT_IEEE_FLOAT; // 32 bits are IEEE FLOAT in this class
} else {
$this->_audioSubFormat = self::WAVE_SUBFORMAT_PCM; // 8, 16 and 24 bits are PCM in this class
}
} else {
$this->_audioSubFormat = $audioSubFormat;
}
return $this;
}
public function getNumChannels() {
return $this->_numChannels;
}
public function setNumChannels($numChannels) {
if ($numChannels < 1 || $numChannels > self::MAX_CHANNEL) {
throw new WavFileException('Unsupported number of channels. Only up to ' . self::MAX_CHANNEL . ' channels are supported.');
} elseif ($this->_samples !== '') {
trigger_error('Wav already has sample data. Changing the number of channels does not convert and may corrupt the data.', E_USER_NOTICE);
}
$this->_numChannels = (int)$numChannels;
$this->setAudioFormat() // implicit setAudioSubFormat(), setFactChunkSize(), setFmtExtendedSize(), setFmtChunkSize(), setSize(), setActualSize(), setDataOffset()
->setByteRate()
->setBlockAlign(); // implicit setNumBlocks()
return $this;
}
public function getChannelMask() {
return $this->_channelMask;
}
public function setChannelMask($channelMask = self::SPEAKER_DEFAULT) {
if ($channelMask != 0) {
// count number of set bits - Hamming weight
$c = (int)$channelMask;
$n = 0;
while ($c > 0) {
$n += $c & 1;
$c >>= 1;
}
if ($n != $this->_numChannels || (((int)$channelMask | self::SPEAKER_ALL) != self::SPEAKER_ALL)) {
throw new WavFileException('Invalid channel mask. The number of channels does not match the number of locations in the mask.');
}
}
$this->_channelMask = (int)$channelMask;
$this->setAudioFormat(); // implicit setAudioSubFormat(), setFactChunkSize(), setFmtExtendedSize(), setFmtChunkSize(), setSize(), setActualSize(), setDataOffset()
return $this;
}
public function getSampleRate() {
return $this->_sampleRate;
}
public function setSampleRate($sampleRate) {
if ($sampleRate < 1 || $sampleRate > self::MAX_SAMPLERATE) {
throw new WavFileException('Invalid sample rate.');
} elseif ($this->_samples !== '') {
trigger_error('Wav already has sample data. Changing the sample rate does not convert the data and may yield undesired results.', E_USER_NOTICE);
}
$this->_sampleRate = (int)$sampleRate;
$this->setByteRate();
return $this;
}
public function getBitsPerSample() {
return $this->_bitsPerSample;
}
public function setBitsPerSample($bitsPerSample) {
if (!in_array($bitsPerSample, array(8, 16, 24, 32))) {
throw new WavFileException('Unsupported bits per sample. Only 8, 16, 24 and 32 bits are supported.');
} elseif ($this->_samples !== '') {
trigger_error('Wav already has sample data. Changing the bits per sample does not convert and may corrupt the data.', E_USER_NOTICE);
}
$this->_bitsPerSample = (int)$bitsPerSample;
$this->setValidBitsPerSample() // implicit setAudioFormat(), setAudioSubFormat(), setFmtChunkSize(), setFactChunkSize(), setSize(), setActualSize(), setDataOffset()
->setByteRate()
->setBlockAlign(); // implicit setNumBlocks()
return $this;
}
public function getValidBitsPerSample() {
return $this->_validBitsPerSample;
}
protected function setValidBitsPerSample($validBitsPerSample = null) {
if (is_null($validBitsPerSample)) {
$this->_validBitsPerSample = $this->_bitsPerSample;
} else {
if ($validBitsPerSample < 1 || $validBitsPerSample > $this->_bitsPerSample) {
throw new WavFileException('ValidBitsPerSample cannot be greater than BitsPerSample.');
}
$this->_validBitsPerSample = (int)$validBitsPerSample;
}
$this->setAudioFormat(); // implicit setAudioSubFormat(), setFactChunkSize(), setFmtExtendedSize(), setFmtChunkSize(), setSize(), setActualSize(), setDataOffset()
return $this;
}
public function getBlockAlign() {
return $this->_blockAlign;
}
protected function setBlockAlign($blockAlign = null) {
if (is_null($blockAlign)) {
$this->_blockAlign = $this->_numChannels * $this->_bitsPerSample / 8;
} else {
$this->_blockAlign = $blockAlign;
}
$this->setNumBlocks();
return $this;
}
public function getNumBlocks()
{
return $this->_numBlocks;
}
protected function setNumBlocks($numBlocks = null) {
if (is_null($numBlocks)) {
$this->_numBlocks = (int)($this->_dataSize / $this->_blockAlign); // do not count incomplete sample blocks
} else {
$this->_numBlocks = $numBlocks;
}
return $this;
}
public function getByteRate() {
return $this->_byteRate;
}
protected function setByteRate($byteRate = null) {
if (is_null($byteRate)) {
$this->_byteRate = $this->_sampleRate * $this->_numChannels * $this->_bitsPerSample / 8;
} else {
$this->_byteRate = $byteRate;
}
return $this;
}
public function getSamples() {
return $this->_samples;
}
public function setSamples(&$samples = '') {
if (strlen($samples) % $this->_blockAlign != 0) {
throw new WavFileException('Incorrect samples size. Has to be a multiple of BlockAlign.');
}
$this->_samples = $samples;
$this->setDataSize(); // implicit setSize(), setActualSize(), setNumBlocks()
return $this;
}
/*%******************************************************************************************%*/
// Getters
public function getMinAmplitude()
{
if ($this->_bitsPerSample == 8) {
return 0;
} elseif ($this->_bitsPerSample == 32) {
return -1.0;
} else {
return -(1 << ($this->_bitsPerSample - 1));
}
}
public function getZeroAmplitude()
{
if ($this->_bitsPerSample == 8) {
return 0x80;
} elseif ($this->_bitsPerSample == 32) {
return 0.0;
} else {
return 0;
}
}
public function getMaxAmplitude()
{
if($this->_bitsPerSample == 8) {
return 0xFF;
} elseif($this->_bitsPerSample == 32) {
return 1.0;
} else {
return (1 << ($this->_bitsPerSample - 1)) - 1;
}
}
/*%******************************************************************************************%*/
// Wave file methods
/**
* Construct a wav header from this object. Includes "fact" chunk in necessary.
* http://www-mmsp.ece.mcgill.ca/documents/audioformats/wave/wave.html
*
* @return string The RIFF header data.
*/
public function makeHeader()
{
// reset and recalculate
$this->setAudioFormat(); // implicit setAudioSubFormat(), setFactChunkSize(), setFmtExtendedSize(), setFmtChunkSize(), setSize(), setActualSize(), setDataOffset()
$this->setNumBlocks();
// RIFF header
$header = pack('N', 0x52494646); // ChunkID - "RIFF"
$header .= pack('V', $this->getChunkSize()); // ChunkSize
$header .= pack('N', 0x57415645); // Format - "WAVE"
// "fmt " subchunk
$header .= pack('N', 0x666d7420); // SubchunkID - "fmt "
$header .= pack('V', $this->getFmtChunkSize()); // SubchunkSize
$header .= pack('v', $this->getAudioFormat()); // AudioFormat
$header .= pack('v', $this->getNumChannels()); // NumChannels
$header .= pack('V', $this->getSampleRate()); // SampleRate
$header .= pack('V', $this->getByteRate()); // ByteRate
$header .= pack('v', $this->getBlockAlign()); // BlockAlign
$header .= pack('v', $this->getBitsPerSample()); // BitsPerSample
if($this->getFmtExtendedSize() == 24) {
$header .= pack('v', 22); // extension size = 24 bytes, cbSize: 24 - 2 = 22 bytes
$header .= pack('v', $this->getValidBitsPerSample()); // ValidBitsPerSample
$header .= pack('V', $this->getChannelMask()); // ChannelMask
$header .= pack('H32', $this->getAudioSubFormat()); // SubFormat
} elseif ($this->getFmtExtendedSize() == 2) {
$header .= pack('v', 0); // extension size = 2 bytes, cbSize: 2 - 2 = 0 bytes
}
// "fact" subchunk
if ($this->getFactChunkSize() == 4) {
$header .= pack('N', 0x66616374); // SubchunkID - "fact"
$header .= pack('V', 4); // SubchunkSize
$header .= pack('V', $this->getNumBlocks()); // SampleLength (per channel)
}
return $header;
}
/**
* Construct wav DATA chunk.
*
* @return string The DATA header and chunk.
*/
public function getDataSubchunk()
{
// check preconditions
if (!$this->_dataSize_valid) {
$this->setDataSize(); // implicit setSize(), setActualSize(), setNumBlocks()
}
// create subchunk
return pack('N', 0x64617461) . // SubchunkID - "data"
pack('V', $this->getDataSize()) . // SubchunkSize
$this->_samples . // Subchunk data
($this->getDataSize() & 1 ? chr(0) : ''); // padding byte
}
/**
* Save the wav data to a file.
*
* @param string $filename (Required) The file path to save the wav to.
* @throws WavFileException
*/
public function save($filename)
{
$fp = @fopen($filename, 'w+b');
if (!is_resource($fp)) {
throw new WavFileException('Failed to open "' . $filename . '" for writing.');
}
fwrite($fp, $this->makeHeader());
fwrite($fp, $this->getDataSubchunk());
fclose($fp);
return $this;
}
/**
* Reads a wav header and data from a file.
*
* @param string $filename (Required) The path to the wav file to read.
* @param bool $readData (Optional) If true, also read the data chunk.
* @throws WavFormatException
* @throws WavFileException
*/
public function openWav($filename, $readData = true)
{
// check preconditions
if (!file_exists($filename)) {
throw new WavFileException('Failed to open "' . $filename . '". File not found.');
} elseif (!is_readable($filename)) {
throw new WavFileException('Failed to open "' . $filename . '". File is not readable.');
} elseif (is_resource($this->_fp)) {
$this->closeWav();
}
// open the file
$this->_fp = @fopen($filename, 'rb');
if (!is_resource($this->_fp)) {
throw new WavFileException('Failed to open "' . $filename . '".');
}
// read the file
return $this->readWav($readData);
}
/**
* Close a with openWav() previously opened wav file or free the buffer of setWavData().
* Not necessary if the data has been read (readData = true) already.
*/
public function closeWav() {
if (is_resource($this->_fp)) fclose($this->_fp);
return $this;
}
/**
* Set the wav file data and properties from a wav file in a string.
*
* @param string $data (Required) The wav file data. Passed by reference.
* @param bool $free (Optional) True to free the passed $data after copying.
* @throws WavFormatException
* @throws WavFileException
*/
public function setWavData(&$data, $free = true)
{
// check preconditions
if (is_resource($this->_fp)) $this->closeWav();
// open temporary stream in memory
$this->_fp = @fopen('php://memory', 'w+b');
if (!is_resource($this->_fp)) {
throw new WavFileException('Failed to open memory stream to write wav data. Use openWav() instead.');
}
// prepare stream
fwrite($this->_fp, $data);
rewind($this->_fp);
// free the passed data
if ($free) $data = null;
// read the stream like a file
return $this->readWav(true);
}
/**
* Read wav file from a stream.
*
* @param $readData (Optional) If true, also read the data chunk.
* @throws WavFormatException
* @throws WavFileException
*/
protected function readWav($readData = true)
{
if (!is_resource($this->_fp)) {
throw new WavFileException('No wav file open. Use openWav() first.');
}
try {
$this->readWavHeader();
} catch (WavFileException $ex) {
$this->closeWav();
throw $ex;
}
if ($readData) return $this->readWavData();
return $this;
}
/**
* Parse a wav header.
* http://www-mmsp.ece.mcgill.ca/documents/audioformats/wave/wave.html
*
* @throws WavFormatException
* @throws WavFileException
*/
protected function readWavHeader()
{
if (!is_resource($this->_fp)) {
throw new WavFileException('No wav file open. Use openWav() first.');
}
// get actual file size
$stat = fstat($this->_fp);
$actualSize = $stat['size'];
$this->_actualSize = $actualSize;
// read the common header
$header = fread($this->_fp, 36); // minimum size of the wav header
if (strlen($header) < 36) {
throw new WavFormatException('Not wav format. Header too short.', 1);
}
// check "RIFF" header
$RIFF = unpack('NChunkID/VChunkSize/NFormat', $header);
if ($RIFF['ChunkID'] != 0x52494646) { // "RIFF"
throw new WavFormatException('Not wav format. "RIFF" signature missing.', 2);
}
if ($actualSize - 8 < $RIFF['ChunkSize']) {
trigger_error('"RIFF" chunk size does not match actual file size. Found ' . $RIFF['ChunkSize'] . ', expected ' . ($actualSize - 8) . '.', E_USER_NOTICE);
$RIFF['ChunkSize'] = $actualSize - 8;
//throw new WavFormatException('"RIFF" chunk size does not match actual file size. Found ' . $RIFF['ChunkSize'] . ', expected ' . ($actualSize - 8) . '.', 3);
}
if ($RIFF['Format'] != 0x57415645) { // "WAVE"
throw new WavFormatException('Not wav format. "RIFF" chunk format is not "WAVE".', 4);
}
$this->_chunkSize = $RIFF['ChunkSize'];
// check common "fmt " subchunk
$fmt = unpack('NSubchunkID/VSubchunkSize/vAudioFormat/vNumChannels/'
.'VSampleRate/VByteRate/vBlockAlign/vBitsPerSample',
substr($header, 12));
if ($fmt['SubchunkID'] != 0x666d7420) { // "fmt "
throw new WavFormatException('Bad wav header. Expected "fmt " subchunk.', 11);
}
if ($fmt['SubchunkSize'] < 16) {
throw new WavFormatException('Bad "fmt " subchunk size.', 12);
}
if ( $fmt['AudioFormat'] != self::WAVE_FORMAT_PCM
&& $fmt['AudioFormat'] != self::WAVE_FORMAT_IEEE_FLOAT
&& $fmt['AudioFormat'] != self::WAVE_FORMAT_EXTENSIBLE)
{
throw new WavFormatException('Unsupported audio format. Only PCM or IEEE FLOAT (EXTENSIBLE) audio is supported.', 13);
}
if ($fmt['NumChannels'] < 1 || $fmt['NumChannels'] > self::MAX_CHANNEL) {
throw new WavFormatException('Invalid number of channels in "fmt " subchunk.', 14);
}
if ($fmt['SampleRate'] < 1 || $fmt['SampleRate'] > self::MAX_SAMPLERATE) {
throw new WavFormatException('Invalid sample rate in "fmt " subchunk.', 15);
}
if ( ($fmt['AudioFormat'] == self::WAVE_FORMAT_PCM && !in_array($fmt['BitsPerSample'], array(8, 16, 24)))
|| ($fmt['AudioFormat'] == self::WAVE_FORMAT_IEEE_FLOAT && $fmt['BitsPerSample'] != 32)
|| ($fmt['AudioFormat'] == self::WAVE_FORMAT_EXTENSIBLE && !in_array($fmt['BitsPerSample'], array(8, 16, 24, 32))))
{
throw new WavFormatException('Only 8, 16 and 24-bit PCM and 32-bit IEEE FLOAT (EXTENSIBLE) audio is supported.', 16);
}
$blockAlign = $fmt['NumChannels'] * $fmt['BitsPerSample'] / 8;
if ($blockAlign != $fmt['BlockAlign']) {
trigger_error('Invalid block align in "fmt " subchunk. Found ' . $fmt['BlockAlign'] . ', expected ' . $blockAlign . '.', E_USER_NOTICE);
$fmt['BlockAlign'] = $blockAlign;
//throw new WavFormatException('Invalid block align in "fmt " subchunk. Found ' . $fmt['BlockAlign'] . ', expected ' . $blockAlign . '.', 17);
}
$byteRate = $fmt['SampleRate'] * $blockAlign;
if ($byteRate != $fmt['ByteRate']) {
trigger_error('Invalid average byte rate in "fmt " subchunk. Found ' . $fmt['ByteRate'] . ', expected ' . $byteRate . '.', E_USER_NOTICE);
$fmt['ByteRate'] = $byteRate;
//throw new WavFormatException('Invalid average byte rate in "fmt " subchunk. Found ' . $fmt['ByteRate'] . ', expected ' . $byteRate . '.', 18);
}
$this->_fmtChunkSize = $fmt['SubchunkSize'];
$this->_audioFormat = $fmt['AudioFormat'];
$this->_numChannels = $fmt['NumChannels'];
$this->_sampleRate = $fmt['SampleRate'];
$this->_byteRate = $fmt['ByteRate'];
$this->_blockAlign = $fmt['BlockAlign'];
$this->_bitsPerSample = $fmt['BitsPerSample'];
// read extended "fmt " subchunk data
$extendedFmt = '';
if ($fmt['SubchunkSize'] > 16) {
// possibly handle malformed subchunk without a padding byte
$extendedFmt = fread($this->_fp, $fmt['SubchunkSize'] - 16 + ($fmt['SubchunkSize'] & 1)); // also read padding byte
if (strlen($extendedFmt) < $fmt['SubchunkSize'] - 16) {
throw new WavFormatException('Not wav format. Header too short.', 1);
}
}
// check extended "fmt " for EXTENSIBLE Audio Format
if ($fmt['AudioFormat'] == self::WAVE_FORMAT_EXTENSIBLE) {
if (strlen($extendedFmt) < 24) {
throw new WavFormatException('Invalid EXTENSIBLE "fmt " subchunk size. Found ' . $fmt['SubchunkSize'] . ', expected at least 40.', 19);
}
$extensibleFmt = unpack('vSize/vValidBitsPerSample/VChannelMask/H32SubFormat', substr($extendedFmt, 0, 24));
if ( $extensibleFmt['SubFormat'] != self::WAVE_SUBFORMAT_PCM
&& $extensibleFmt['SubFormat'] != self::WAVE_SUBFORMAT_IEEE_FLOAT)
{
throw new WavFormatException('Unsupported audio format. Only PCM or IEEE FLOAT (EXTENSIBLE) audio is supported.', 13);
}
if ( ($extensibleFmt['SubFormat'] == self::WAVE_SUBFORMAT_PCM && !in_array($fmt['BitsPerSample'], array(8, 16, 24)))
|| ($extensibleFmt['SubFormat'] == self::WAVE_SUBFORMAT_IEEE_FLOAT && $fmt['BitsPerSample'] != 32))
{
throw new WavFormatException('Only 8, 16 and 24-bit PCM and 32-bit IEEE FLOAT (EXTENSIBLE) audio is supported.', 16);
}
if ($extensibleFmt['Size'] != 22) {
trigger_error('Invaid extension size in EXTENSIBLE "fmt " subchunk.', E_USER_NOTICE);
$extensibleFmt['Size'] = 22;
//throw new WavFormatException('Invaid extension size in EXTENSIBLE "fmt " subchunk.', 20);
}
if ($extensibleFmt['ValidBitsPerSample'] != $fmt['BitsPerSample']) {
trigger_error('Invaid or unsupported valid bits per sample in EXTENSIBLE "fmt " subchunk.', E_USER_NOTICE);
$extensibleFmt['ValidBitsPerSample'] = $fmt['BitsPerSample'];
//throw new WavFormatException('Invaid or unsupported valid bits per sample in EXTENSIBLE "fmt " subchunk.', 21);
}
if ($extensibleFmt['ChannelMask'] != 0) {
// count number of set bits - Hamming weight
$c = (int)$extensibleFmt['ChannelMask'];
$n = 0;
while ($c > 0) {
$n += $c & 1;
$c >>= 1;
}
if ($n != $fmt['NumChannels'] || (((int)$extensibleFmt['ChannelMask'] | self::SPEAKER_ALL) != self::SPEAKER_ALL)) {
trigger_error('Invalid channel mask in EXTENSIBLE "fmt " subchunk. The number of channels does not match the number of locations in the mask.', E_USER_NOTICE);
$extensibleFmt['ChannelMask'] = 0;
//throw new WavFormatException('Invalid channel mask in EXTENSIBLE "fmt " subchunk. The number of channels does not match the number of locations in the mask.', 22);
}
}
$this->_fmtExtendedSize = strlen($extendedFmt);
$this->_validBitsPerSample = $extensibleFmt['ValidBitsPerSample'];
$this->_channelMask = $extensibleFmt['ChannelMask'];
$this->_audioSubFormat = $extensibleFmt['SubFormat'];
} else {
$this->_fmtExtendedSize = strlen($extendedFmt);
$this->_validBitsPerSample = $fmt['BitsPerSample'];
$this->_channelMask = 0;
$this->_audioSubFormat = null;
}
// read additional subchunks until "data" subchunk is found
$factSubchunk = array();
$dataSubchunk = array();
while (!feof($this->_fp)) {
$subchunkHeader = fread($this->_fp, 8);
if (strlen($subchunkHeader) < 8) {
throw new WavFormatException('Missing "data" subchunk.', 101);
}
$subchunk = unpack('NSubchunkID/VSubchunkSize', $subchunkHeader);
if ($subchunk['SubchunkID'] == 0x66616374) { // "fact"
// possibly handle malformed subchunk without a padding byte
$subchunkData = fread($this->_fp, $subchunk['SubchunkSize'] + ($subchunk['SubchunkSize'] & 1)); // also read padding byte
if (strlen($subchunkData) < 4) {
throw new WavFormatException('Invalid "fact" subchunk.', 102);
}
$factParams = unpack('VSampleLength', substr($subchunkData, 0, 4));
$factSubchunk = array_merge($subchunk, $factParams);
} elseif ($subchunk['SubchunkID'] == 0x64617461) { // "data"
$dataSubchunk = $subchunk;
break;
} elseif ($subchunk['SubchunkID'] == 0x7761766C) { // "wavl"
throw new WavFormatException('Wave List Chunk ("wavl" subchunk) is not supported.', 106);
} else {
// skip all other (unknown) subchunks
// possibly handle malformed subchunk without a padding byte
if ( $subchunk['SubchunkSize'] < 0
|| fseek($this->_fp, $subchunk['SubchunkSize'] + ($subchunk['SubchunkSize'] & 1), SEEK_CUR) !== 0) { // also skip padding byte
throw new WavFormatException('Invalid subchunk (0x' . dechex($subchunk['SubchunkID']) . ') encountered.', 103);
}
}
}
if (empty($dataSubchunk)) {
throw new WavFormatException('Missing "data" subchunk.', 101);
}
// check "data" subchunk
$dataOffset = ftell($this->_fp);
if ($dataSubchunk['SubchunkSize'] < 0 || $actualSize - $dataOffset < $dataSubchunk['SubchunkSize']) {
trigger_error('Invalid "data" subchunk size.', E_USER_NOTICE);
$dataSubchunk['SubchunkSize'] = $actualSize - $dataOffset;
//throw new WavFormatException('Invalid "data" subchunk size.', 104);
}
$this->_dataOffset = $dataOffset;
$this->_dataSize = $dataSubchunk['SubchunkSize'];
$this->_dataSize_fp = $dataSubchunk['SubchunkSize'];
$this->_dataSize_valid = false;
$this->_samples = '';
// check "fact" subchunk
$numBlocks = (int)($dataSubchunk['SubchunkSize'] / $fmt['BlockAlign']);
if (empty($factSubchunk)) { // construct fake "fact" subchunk
$factSubchunk = array('SubchunkSize' => 0, 'SampleLength' => $numBlocks);
}
if ($factSubchunk['SampleLength'] != $numBlocks) {
trigger_error('Invalid sample length in "fact" subchunk.', E_USER_NOTICE);
$factSubchunk['SampleLength'] = $numBlocks;
//throw new WavFormatException('Invalid sample length in "fact" subchunk.', 105);
}
$this->_factChunkSize = $factSubchunk['SubchunkSize'];
$this->_numBlocks = $factSubchunk['SampleLength'];
return $this;
}
/**
* Read the wav data from the file into the buffer.
*
* @param $dataOffset (Optional) The byte offset to skip before starting to read. Must be a multiple of BlockAlign.
* @param $dataSize (Optional) The size of the data to read in bytes. Must be a multiple of BlockAlign. Defaults to all data.
* @throws WavFileException
*/
public function readWavData($dataOffset = 0, $dataSize = null)
{
// check preconditions
if (!is_resource($this->_fp)) {
throw new WavFileException('No wav file open. Use openWav() first.');
}
if ($dataOffset < 0 || $dataOffset % $this->getBlockAlign() > 0) {
throw new WavFileException('Invalid data offset. Has to be a multiple of BlockAlign.');
}
if (is_null($dataSize)) {
$dataSize = $this->_dataSize_fp - ($this->_dataSize_fp % $this->getBlockAlign()); // only read complete blocks
} elseif ($dataSize < 0 || $dataSize % $this->getBlockAlign() > 0) {
throw new WavFileException('Invalid data size to read. Has to be a multiple of BlockAlign.');
}
// skip offset
if ($dataOffset > 0 && fseek($this->_fp, $dataOffset, SEEK_CUR) !== 0) {
throw new WavFileException('Seeking to data offset failed.');
}
// read data
$this->_samples .= fread($this->_fp, $dataSize); // allow appending
$this->setDataSize(); // implicit setSize(), setActualSize(), setNumBlocks()
// close file or memory stream
return $this->closeWav();
}
/*%******************************************************************************************%*/
// Sample manipulation methods
/**
* Return a single sample block from the file.
*
* @param int $blockNum (Required) The sample block number. Zero based.
* @return string The binary sample block (all channels). Returns null if the sample block number was out of range.
*/
public function getSampleBlock($blockNum)
{
// check preconditions
if (!$this->_dataSize_valid) {
$this->setDataSize(); // implicit setSize(), setActualSize(), setNumBlocks()
}
$offset = $blockNum * $this->_blockAlign;
if ($offset + $this->_blockAlign > $this->_dataSize || $offset < 0) {
return null;
}
// read data
return substr($this->_samples, $offset, $this->_blockAlign);
}
/**
* Set a single sample block.
* Allows to append a sample block.
*
* @param string $sampleBlock (Required) The binary sample block (all channels).
* @param int $blockNum (Required) The sample block number. Zero based.
* @throws WavFileException
*/
public function setSampleBlock($sampleBlock, $blockNum)
{
// check preconditions
$blockAlign = $this->_blockAlign;
if (!isset($sampleBlock[$blockAlign - 1]) || isset($sampleBlock[$blockAlign])) { // faster than: if (strlen($sampleBlock) != $blockAlign)
throw new WavFileException('Incorrect sample block size. Got ' . strlen($sampleBlock) . ', expected ' . $blockAlign . '.');
}
if (!$this->_dataSize_valid) {
$this->setDataSize(); // implicit setSize(), setActualSize(), setNumBlocks()
}
$numBlocks = (int)($this->_dataSize / $blockAlign);
$offset = $blockNum * $blockAlign;
if ($blockNum > $numBlocks || $blockNum < 0) { // allow appending
throw new WavFileException('Sample block number is out of range.');
}
// replace or append data
if ($blockNum == $numBlocks) {
// append
$this->_samples .= $sampleBlock;
$this->_dataSize += $blockAlign;
$this->_chunkSize += $blockAlign;
$this->_actualSize += $blockAlign;
$this->_numBlocks++;
} else {
// replace
for ($i = 0; $i < $blockAlign; ++$i) {
$this->_samples[$offset + $i] = $sampleBlock[$i];
}
}
return $this;
}
/**
* Get a float sample value for a specific sample block and channel number.
*
* @param int $blockNum (Required) The sample block number to fetch. Zero based.
* @param int $channelNum (Required) The channel number within the sample block to fetch. First channel is 1.
* @return float The float sample value. Returns null if the sample block number was out of range.
* @throws WavFileException
*/
public function getSampleValue($blockNum, $channelNum)
{
// check preconditions
if ($channelNum < 1 || $channelNum > $this->_numChannels) {
throw new WavFileException('Channel number is out of range.');
}
if (!$this->_dataSize_valid) {
$this->setDataSize(); // implicit setSize(), setActualSize(), setNumBlocks()
}
$sampleBytes = $this->_bitsPerSample / 8;
$offset = $blockNum * $this->_blockAlign + ($channelNum - 1) * $sampleBytes;
if ($offset + $sampleBytes > $this->_dataSize || $offset < 0) {
return null;
}
// read binary value
$sampleBinary = substr($this->_samples, $offset, $sampleBytes);
// convert binary to value
switch ($this->_bitsPerSample) {
case 8:
// unsigned char
return (float)((ord($sampleBinary) - 0x80) / 0x80);
case 16:
// signed short, little endian
$data = unpack('v', $sampleBinary);
$sample = $data[1];
if ($sample >= 0x8000) {
$sample -= 0x10000;
}
return (float)($sample / 0x8000);
case 24:
// 3 byte packed signed integer, little endian
$data = unpack('C3', $sampleBinary);
$sample = $data[1] | ($data[2] << 8) | ($data[3] << 16);
if ($sample >= 0x800000) {
$sample -= 0x1000000;
}
return (float)($sample / 0x800000);
case 32:
// 32-bit float
$data = unpack('f', $sampleBinary);
return (float)$data[1];
default:
return null;
}
}
/**
* Sets a float sample value for a specific sample block number and channel.
* Converts float values to appropriate integer values and clips properly.
* Allows to append samples (in order).
*
* @param float $sampleFloat (Required) The float sample value to set. Converts float values and clips if necessary.
* @param int $blockNum (Required) The sample block number to set or append. Zero based.
* @param int $channelNum (Required) The channel number within the sample block to set or append. First channel is 1.
* @throws WavFileException
*/
public function setSampleValue($sampleFloat, $blockNum, $channelNum)
{
// check preconditions
if ($channelNum < 1 || $channelNum > $this->_numChannels) {
throw new WavFileException('Channel number is out of range.');
}
if (!$this->_dataSize_valid) {
$this->setDataSize(); // implicit setSize(), setActualSize(), setNumBlocks()
}
$dataSize = $this->_dataSize;
$bitsPerSample = $this->_bitsPerSample;
$sampleBytes = $bitsPerSample / 8;
$offset = $blockNum * $this->_blockAlign + ($channelNum - 1) * $sampleBytes;
if (($offset + $sampleBytes > $dataSize && $offset != $dataSize) || $offset < 0) { // allow appending
throw new WavFileException('Sample block or channel number is out of range.');
}
// convert to value, quantize and clip
if ($bitsPerSample == 32) {
$sample = $sampleFloat < -1.0 ? -1.0 : ($sampleFloat > 1.0 ? 1.0 : $sampleFloat);
} else {
$p = 1 << ($bitsPerSample - 1); // 2 to the power of _bitsPerSample divided by 2
// project and quantize (round) float to integer values
$sample = $sampleFloat < 0 ? (int)($sampleFloat * $p - 0.5) : (int)($sampleFloat * $p + 0.5);
// clip if necessary to [-$p, $p - 1]
if ($sample < -$p) {
$sample = -$p;
} elseif ($sample > $p - 1) {
$sample = $p - 1;
}
}
// convert to binary
switch ($bitsPerSample) {
case 8:
// unsigned char
$sampleBinary = chr($sample + 0x80);
break;
case 16:
// signed short, little endian
if ($sample < 0) {
$sample += 0x10000;
}
$sampleBinary = pack('v', $sample);
break;
case 24:
// 3 byte packed signed integer, little endian
if ($sample < 0) {
$sample += 0x1000000;
}
$sampleBinary = pack('C3', $sample & 0xff, ($sample >> 8) & 0xff, ($sample >> 16) & 0xff);
break;
case 32:
// 32-bit float
$sampleBinary = pack('f', $sample);
break;
default:
$sampleBinary = null;
$sampleBytes = 0;
break;
}
// replace or append data
if ($offset == $dataSize) {
// append
$this->_samples .= $sampleBinary;
$this->_dataSize += $sampleBytes;
$this->_chunkSize += $sampleBytes;
$this->_actualSize += $sampleBytes;
$this->_numBlocks = (int)($this->_dataSize / $this->_blockAlign);
} else {
// replace
for ($i = 0; $i < $sampleBytes; ++$i) {
$this->_samples{$offset + $i} = $sampleBinary{$i};
}
}
return $this;
}
/*%******************************************************************************************%*/
// Audio processing methods
/**
* Run samples through audio processing filters.
*
*
* $wav->filter(
* array(
* WavFile::FILTER_MIX => array( // Filter for mixing 2 WavFile instances.
* 'wav' => $wav2, // (Required) The WavFile to mix into this WhavFile. If no optional arguments are given, can be passed without the array.
* 'loop' => true, // (Optional) Loop the selected portion (with warping to the beginning at the end).
* 'blockOffset' => 0, // (Optional) Block number to start mixing from.
* 'numBlocks' => null // (Optional) Number of blocks to mix in or to select for looping. Defaults to the end or all data for looping.
* ),
* WavFile::FILTER_NORMALIZE => 0.6, // (Required) Normalization of (mixed) audio samples - see threshold parameter for normalizeSample().
* WavFile::FILTER_DEGRADE => 0.9 // (Required) Introduce random noise. The quality relative to the amplitude. 1 = no noise, 0 = max. noise.
* ),
* 0, // (Optional) The block number of this WavFile to start with.
* null // (Optional) The number of blocks to process.
* );
*
*
* @param array $filters (Required) An array of 1 or more audio processing filters.
* @param int $blockOffset (Optional) The block number to start precessing from.
* @param int $numBlocks (Optional) The maximum number of blocks to process.
* @throws WavFileException
*/
public function filter($filters, $blockOffset = 0, $numBlocks = null)
{
// check preconditions
$totalBlocks = $this->getNumBlocks();
$numChannels = $this->getNumChannels();
if (is_null($numBlocks)) $numBlocks = $totalBlocks - $blockOffset;
if (!is_array($filters) || empty($filters) || $blockOffset < 0 || $blockOffset > $totalBlocks || $numBlocks <= 0) {
// nothing to do
return $this;
}
// check filtes
$filter_mix = false;
if (array_key_exists(self::FILTER_MIX, $filters)) {
if (!is_array($filters[self::FILTER_MIX])) {
// assume the 'wav' parameter
$filters[self::FILTER_MIX] = array('wav' => $filters[self::FILTER_MIX]);
}
$mix_wav = @$filters[self::FILTER_MIX]['wav'];
if (!($mix_wav instanceof WavFile)) {
throw new WavFileException("WavFile to mix is missing or invalid.");
} elseif ($mix_wav->getSampleRate() != $this->getSampleRate()) {
throw new WavFileException("Sample rate of WavFile to mix does not match.");
} else if ($mix_wav->getNumChannels() != $this->getNumChannels()) {
throw new WavFileException("Number of channels of WavFile to mix does not match.");
}
$mix_loop = @$filters[self::FILTER_MIX]['loop'];
if (is_null($mix_loop)) $mix_loop = false;
$mix_blockOffset = @$filters[self::FILTER_MIX]['blockOffset'];
if (is_null($mix_blockOffset)) $mix_blockOffset = 0;
$mix_totalBlocks = $mix_wav->getNumBlocks();
$mix_numBlocks = @$filters[self::FILTER_MIX]['numBlocks'];
if (is_null($mix_numBlocks)) $mix_numBlocks = $mix_loop ? $mix_totalBlocks : $mix_totalBlocks - $mix_blockOffset;
$mix_maxBlock = min($mix_blockOffset + $mix_numBlocks, $mix_totalBlocks);
$filter_mix = true;
}
$filter_normalize = false;
if (array_key_exists(self::FILTER_NORMALIZE, $filters)) {
$normalize_threshold = @$filters[self::FILTER_NORMALIZE];
if (!is_null($normalize_threshold) && abs($normalize_threshold) != 1) $filter_normalize = true;
}
$filter_degrade = false;
if (array_key_exists(self::FILTER_DEGRADE, $filters)) {
$degrade_quality = @$filters[self::FILTER_DEGRADE];
if (is_null($degrade_quality)) $degrade_quality = 1;
if ($degrade_quality >= 0 && $degrade_quality < 1) $filter_degrade = true;
}
// loop through all sample blocks
for ($block = 0; $block < $numBlocks; ++$block) {
// loop through all channels
for ($channel = 1; $channel <= $numChannels; ++$channel) {
// read current sample
$currentBlock = $blockOffset + $block;
$sampleFloat = $this->getSampleValue($currentBlock, $channel);
/************* MIX FILTER ***********************/
if ($filter_mix) {
if ($mix_loop) {
$mixBlock = ($mix_blockOffset + ($block % $mix_numBlocks)) % $mix_totalBlocks;
} else {
$mixBlock = $mix_blockOffset + $block;
}
if ($mixBlock < $mix_maxBlock) {
$sampleFloat += $mix_wav->getSampleValue($mixBlock, $channel);
}
}
/************* NORMALIZE FILTER *******************/
if ($filter_normalize) {
$sampleFloat = $this->normalizeSample($sampleFloat, $normalize_threshold);
}
/************* DEGRADE FILTER *******************/
if ($filter_degrade) {
$sampleFloat += rand(1000000 * ($degrade_quality - 1), 1000000 * (1 - $degrade_quality)) / 1000000;
}
// write current sample
$this->setSampleValue($sampleFloat, $currentBlock, $channel);
}
}
return $this;
}
/**
* Append a wav file to the current wav.
* The wav files must have the same sample rate, number of bits per sample, and number of channels.
*
* @param WavFile $wav (Required) The wav file to append.
* @throws WavFileException
*/
public function appendWav(WavFile $wav) {
// basic checks
if ($wav->getSampleRate() != $this->getSampleRate()) {
throw new WavFileException("Sample rate for wav files do not match.");
} else if ($wav->getBitsPerSample() != $this->getBitsPerSample()) {
throw new WavFileException("Bits per sample for wav files do not match.");
} else if ($wav->getNumChannels() != $this->getNumChannels()) {
throw new WavFileException("Number of channels for wav files do not match.");
}
$this->_samples .= $wav->_samples;
$this->setDataSize(); // implicit setSize(), setActualSize(), setNumBlocks()
return $this;
}
/**
* Mix 2 wav files together.
* Both wavs must have the same sample rate and same number of channels.
*
* @param WavFile $wav (Required) The WavFile to mix.
* @param float $normalizeThreshold (Optional) See normalizeSample for an explanation.
* @throws WavFileException
*/
public function mergeWav(WavFile $wav, $normalizeThreshold = null) {
return $this->filter(array(
WavFile::FILTER_MIX => $wav,
WavFile::FILTER_NORMALIZE => $normalizeThreshold
));
}
/**
* Add silence to the wav file.
*
* @param float $duration (Optional) How many seconds of silence. If negative, add to the beginning of the file. Defaults to 1s.
*/
public function insertSilence($duration = 1.0)
{
$numSamples = (int)($this->getSampleRate() * abs($duration));
$numChannels = $this->getNumChannels();
$data = str_repeat(self::packSample($this->getZeroAmplitude(), $this->getBitsPerSample()), $numSamples * $numChannels);
if ($duration >= 0) {
$this->_samples .= $data;
} else {
$this->_samples = $data . $this->_samples;
}
$this->setDataSize(); // implicit setSize(), setActualSize(), setNumBlocks()
return $this;
}
/**
* Degrade the quality of the wav file by introducing random noise.
*
* @param float quality (Optional) The quality relative to the amplitude. 1 = no noise, 0 = max. noise.
*/
public function degrade($quality = 1.0)
{
return $this->filter(self::FILTER_DEGRADE, array(
WavFile::FILTER_DEGRADE => $quality
));
}
/**
* Generate noise at the end of the wav for the specified duration and volume.
*
* @param float $duration (Optional) Number of seconds of noise to generate.
* @param float $percent (Optional) The percentage of the maximum amplitude to use. 100 = full amplitude.
*/
public function generateNoise($duration = 1.0, $percent = 100)
{
$numChannels = $this->getNumChannels();
$numSamples = $this->getSampleRate() * $duration;
$minAmp = $this->getMinAmplitude();
$maxAmp = $this->getMaxAmplitude();
$bitDepth = $this->getBitsPerSample();
for ($s = 0; $s < $numSamples; ++$s) {
if ($bitDepth == 32) {
$val = rand(-$percent * 10000, $percent * 10000) / 1000000;
} else {
$val = rand($minAmp, $maxAmp);
$val = (int)($val * $percent / 100);
}
$this->_samples .= str_repeat(self::packSample($val, $bitDepth), $numChannels);
}
$this->setDataSize(); // implicit setSize(), setActualSize(), setNumBlocks()
return $this;
}
/**
* Convert sample data to different bits per sample.
*
* @param int $bitsPerSample (Required) The new number of bits per sample;
* @throws WavFileException
*/
public function convertBitsPerSample($bitsPerSample) {
if ($this->getBitsPerSample() == $bitsPerSample) {
return $this;
}
$tempWav = new WavFile($this->getNumChannels(), $this->getSampleRate(), $bitsPerSample);
$tempWav->filter(
array(self::FILTER_MIX => $this),
0,
$this->getNumBlocks()
);
$this->setSamples() // implicit setDataSize(), setSize(), setActualSize(), setNumBlocks()
->setBitsPerSample($bitsPerSample); // implicit setValidBitsPerSample(), setAudioFormat(), setAudioSubFormat(), setFmtChunkSize(), setFactChunkSize(), setSize(), setActualSize(), setDataOffset(), setByteRate(), setBlockAlign(), setNumBlocks()
$this->_samples = $tempWav->_samples;
$this->setDataSize(); // implicit setSize(), setActualSize(), setNumBlocks()
return $this;
}
/*%******************************************************************************************%*/
// Miscellaneous methods
/**
* Output information about the wav object.
*/
public function displayInfo()
{
$s = "File Size: %u\n"
."Chunk Size: %u\n"
."fmt Subchunk Size: %u\n"
."Extended fmt Size: %u\n"
."fact Subchunk Size: %u\n"
."Data Offset: %u\n"
."Data Size: %u\n"
."Audio Format: %s\n"
."Audio SubFormat: %s\n"
."Channels: %u\n"
."Channel Mask: 0x%s\n"
."Sample Rate: %u\n"
."Bits Per Sample: %u\n"
."Valid Bits Per Sample: %u\n"
."Sample Block Size: %u\n"
."Number of Sample Blocks: %u\n"
."Byte Rate: %uBps\n";
$s = sprintf($s, $this->getActualSize(),
$this->getChunkSize(),
$this->getFmtChunkSize(),
$this->getFmtExtendedSize(),
$this->getFactChunkSize(),
$this->getDataOffset(),
$this->getDataSize(),
$this->getAudioFormat() == self::WAVE_FORMAT_PCM ? 'PCM' : ($this->getAudioFormat() == self::WAVE_FORMAT_IEEE_FLOAT ? 'IEEE FLOAT' : 'EXTENSIBLE'),
$this->getAudioSubFormat() == self::WAVE_SUBFORMAT_PCM ? 'PCM' : 'IEEE FLOAT',
$this->getNumChannels(),
dechex($this->getChannelMask()),
$this->getSampleRate(),
$this->getBitsPerSample(),
$this->getValidBitsPerSample(),
$this->getBlockAlign(),
$this->getNumBlocks(),
$this->getByteRate());
if (php_sapi_name() == 'cli') {
return $s;
} else {
return nl2br($s);
}
}
}
/*%******************************************************************************************%*/
// Exceptions
/**
* WavFileException indicates an illegal state or argument in this class.
*/
class WavFileException extends Exception {}
/**
* WavFormatException indicates a malformed or unsupported wav file header.
*/
class WavFormatException extends WavFileException {}