WaveFileCreator.createALawMulawHeader_ - Code Metrics - Inspection of "Keep file metadata when converting to ADPCM" - rochars/wavefile - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Push — master ( 5a0225...e0b877 )

by Rafael S.

created 2019-09-11 07:49 UTC

WaveFileCreator.createALawMulawHeader_ A

↳ Parent: WaveFileCreator

Complexity

Conditions

Size

Total Lines	13
Code Lines	11

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
eloc	11
dl	0
loc	13
rs	9.85
c	0
b	0
f	0
cc	1

/*
 * Copyright (c) 2017-2019 Rafael da Silva Rocha.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

/**
 * @fileoverview The WaveFileCreator class.
 * @see https://github.com/rochars/wavefile
 */

/** @module wavefile */

import WaveFileParser from './wavefile-parser';
import interleave from './interleave';
import dwChannelMask from './dw-channel-mask';
import validateNumChannels from './validate-num-channels'; 
import validateSampleRate from './validate-sample-rate';
import {packArrayTo, packTo, unpack} from 'byte-data';

/**
 * A class to read, write and create wav files.
 * @extends WaveFileParser
 */
export default class WaveFileCreator extends WaveFileParser {

  constructor() {
    super();
    /**
     * The bit depth code according to the samples.
     * @type {string}
     */
    this.bitDepth = '0';
    /**
     * @type {!Object}
     * @protected
     */
    this.dataType = {};
    /**
     * Audio formats.
     * Formats not listed here should be set to 65534,
     * the code for WAVE_FORMAT_EXTENSIBLE
     * @enum {number}
     * @protected
     */
    this.WAV_AUDIO_FORMATS = {
      '4': 17,
      '8': 1,
      '8a': 6,
      '8m': 7,
      '16': 1,
      '24': 1,
      '32': 1,
      '32f': 3,
      '64': 3
    };
  }

  /**
   * Set up the WaveFileCreator object based on the arguments passed.
   * Existing chunks are reset.
   * @param {number} numChannels The number of channels
   *    (Integer numbers: 1 for mono, 2 stereo and so on).
   * @param {number} sampleRate The sample rate.
   *    Integer numbers like 8000, 44100, 48000, 96000, 192000.
   * @param {string} bitDepthCode The audio bit depth code.
   *    One of '4', '8', '8a', '8m', '16', '24', '32', '32f', '64'
   *    or any value between '8' and '32' (like '12').
   * @param {!Array<number>|!Array<!Array<number>>|!TypedArray} samples
   *    The samples. Must be in the correct range according to the bit depth.
   * @param {?Object} options Optional. Used to force the container
   *    as RIFX with {'container': 'RIFX'}
   * @throws {Error} If any argument does not meet the criteria.
   */
  fromScratch(numChannels, sampleRate, bitDepthCode, samples, options={}) {
    // reset all chunks
    this.clearHeaders();
    this.newWavFile_(numChannels, sampleRate, bitDepthCode, samples, options);
  }

  /**
   * Set up the WaveFileCreator object based on the arguments passed.
   * @param {number} numChannels The number of channels
   *    (Integer numbers: 1 for mono, 2 stereo and so on).
   * @param {number} sampleRate The sample rate.
   *    Integer numbers like 8000, 44100, 48000, 96000, 192000.
   * @param {string} bitDepthCode The audio bit depth code.
   *    One of '4', '8', '8a', '8m', '16', '24', '32', '32f', '64'
   *    or any value between '8' and '32' (like '12').
   * @param {!Array<number>|!Array<!Array<number>>|!TypedArray} samples
   *    The samples. Must be in the correct range according to the bit depth.
   * @param {?Object} options Optional. Used to force the container
   *    as RIFX with {'container': 'RIFX'}
   * @throws {Error} If any argument does not meet the criteria.
   * @private
   */
  newWavFile_(numChannels, sampleRate, bitDepthCode, samples, options={}) {
    if (!options.container) {
      options.container = 'RIFF';
    }
    this.container = options.container;
    this.bitDepth = bitDepthCode;
    samples = interleave(samples);
    this.updateDataType_();
    /** @type {number} */
    let numBytes = this.dataType.bits / 8;
    this.data.samples = new Uint8Array(samples.length * numBytes);
    packArrayTo(samples, this.dataType, this.data.samples);
    this.makeWavHeader_(
      bitDepthCode, numChannels, sampleRate,
      numBytes, this.data.samples.length, options);
    this.data.chunkId = 'data';
    this.data.chunkSize = this.data.samples.length;
    this.validateWavHeader_();
  }

  /**
   * Set up the WaveFileParser object from a byte buffer.
   * @param {!Uint8Array} wavBuffer The buffer.
   * @param {boolean=} samples True if the samples should be loaded.
   * @throws {Error} If container is not RIFF, RIFX or RF64.
   * @throws {Error} If format is not WAVE.
   * @throws {Error} If no 'fmt ' chunk is found.
   * @throws {Error} If no 'data' chunk is found.
   */
  fromBuffer(wavBuffer, samples=true) {
    super.fromBuffer(wavBuffer, samples);
    this.bitDepthFromFmt_();
    this.updateDataType_();
  }

  /**
   * Return a byte buffer representig the WaveFileParser object as a .wav file.
   * The return value of this method can be written straight to disk.
   * @return {!Uint8Array} A wav file.
   * @throws {Error} If bit depth is invalid.
   * @throws {Error} If the number of channels is invalid.
   * @throws {Error} If the sample rate is invalid.
   */
  toBuffer() {
    this.validateWavHeader_();
    return super.toBuffer();
  }

  /**
   * Return the sample at a given index.
   * @param {number} index The sample index.
   * @return {number} The sample.
   * @throws {Error} If the sample index is off range.
   */
  getSample(index) {
    index = index * (this.dataType.bits / 8);
    if (index + this.dataType.bits / 8 > this.data.samples.length) {
      throw new Error('Range error');
    }
    return unpack(
      this.data.samples.slice(index, index + this.dataType.bits / 8),
      this.dataType);
  }

  /**
   * Set the sample at a given index.
   * @param {number} index The sample index.
   * @param {number} sample The sample.
   * @throws {Error} If the sample index is off range.
   */
  setSample(index, sample) {
    index = index * (this.dataType.bits / 8);
    if (index + this.dataType.bits / 8 > this.data.samples.length) {
      throw new Error('Range error');
    }
    packTo(sample, this.dataType, this.data.samples, index);
  }

  /**
   * Define the header of a wav file.
   * @param {string} bitDepthCode The audio bit depth
   * @param {number} numChannels The number of channels
   * @param {number} sampleRate The sample rate.
   * @param {number} numBytes The number of bytes each sample use.
   * @param {number} samplesLength The length of the samples in bytes.
   * @param {!Object} options The extra options, like container defintion.
   * @private
   */
  makeWavHeader_(
    bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
    if (bitDepthCode == '4') {
      this.createADPCMHeader_(
        bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);

    } else if (bitDepthCode == '8a' || bitDepthCode == '8m') {
      this.createALawMulawHeader_(
        bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);

    } else if(Object.keys(this.WAV_AUDIO_FORMATS).indexOf(bitDepthCode) == -1 ||
        numChannels > 2) {
      this.createExtensibleHeader_(
        bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);

    } else {
      this.createPCMHeader_(
        bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);      
    }
  }

  /**
   * Create the header of a linear PCM wave file.
   * @param {string} bitDepthCode The audio bit depth
   * @param {number} numChannels The number of channels
   * @param {number} sampleRate The sample rate.
   * @param {number} numBytes The number of bytes each sample use.
   * @param {number} samplesLength The length of the samples in bytes.
   * @param {!Object} options The extra options, like container defintion.
   * @private
   */
  createPCMHeader_(
    bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
    this.container = options.container;
    this.chunkSize = 36 + samplesLength;
    this.format = 'WAVE';
    this.bitDepth = bitDepthCode;
    this.fmt = {
      chunkId: 'fmt ',
      chunkSize: 16,
      audioFormat: this.WAV_AUDIO_FORMATS[bitDepthCode] || 65534,
      numChannels: numChannels,
      sampleRate: sampleRate,
      byteRate: (numChannels * numBytes) * sampleRate,
      blockAlign: numChannels * numBytes,
      bitsPerSample: parseInt(bitDepthCode, 10),
      cbSize: 0,
      validBitsPerSample: 0,
      dwChannelMask: 0,
      subformat: []
    };
  }

  /**
   * Create the header of a ADPCM wave file.
   * @param {string} bitDepthCode The audio bit depth
   * @param {number} numChannels The number of channels
   * @param {number} sampleRate The sample rate.
   * @param {number} numBytes The number of bytes each sample use.
   * @param {number} samplesLength The length of the samples in bytes.
   * @param {!Object} options The extra options, like container defintion.
   * @private
   */
  createADPCMHeader_(
    bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
    this.createPCMHeader_(
      bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
    this.chunkSize = 40 + samplesLength;
    this.fmt.chunkSize = 20;
    this.fmt.byteRate = 4055;
    this.fmt.blockAlign = 256;
    this.fmt.bitsPerSample = 4;
    this.fmt.cbSize = 2;
    this.fmt.validBitsPerSample = 505;
    this.fact = {
      chunkId: 'fact',
      chunkSize: 4,
      dwSampleLength: samplesLength * 2
    };
  }

  /**
   * Create the header of WAVE_FORMAT_EXTENSIBLE file.
   * @param {string} bitDepthCode The audio bit depth
   * @param {number} numChannels The number of channels
   * @param {number} sampleRate The sample rate.
   * @param {number} numBytes The number of bytes each sample use.
   * @param {number} samplesLength The length of the samples in bytes.
   * @param {!Object} options The extra options, like container defintion.
   * @private
   */
  createExtensibleHeader_(
      bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
    this.createPCMHeader_(
      bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
    this.chunkSize = 36 + 24 + samplesLength;
    this.fmt.chunkSize = 40;
    this.fmt.bitsPerSample = ((parseInt(bitDepthCode, 10) - 1) | 7) + 1;
    this.fmt.cbSize = 22;
    this.fmt.validBitsPerSample = parseInt(bitDepthCode, 10);
    this.fmt.dwChannelMask = dwChannelMask(numChannels);
    // subformat 128-bit GUID as 4 32-bit values
    // only supports uncompressed integer PCM samples
    this.fmt.subformat = [1, 1048576, 2852126848, 1905997824];
  }

  /**
   * Create the header of mu-Law and A-Law wave files.
   * @param {string} bitDepthCode The audio bit depth
   * @param {number} numChannels The number of channels
   * @param {number} sampleRate The sample rate.
   * @param {number} numBytes The number of bytes each sample use.
   * @param {number} samplesLength The length of the samples in bytes.
   * @param {!Object} options The extra options, like container defintion.
   * @private
   */
  createALawMulawHeader_(
      bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
    this.createPCMHeader_(
      bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
    this.chunkSize = 40 + samplesLength;
    this.fmt.chunkSize = 20;
    this.fmt.cbSize = 2;
    this.fmt.validBitsPerSample = 8;
    this.fact = {
      chunkId: 'fact',
      chunkSize: 4,
      dwSampleLength: samplesLength
    };
  }

  /**
   * Set the string code of the bit depth based on the 'fmt ' chunk.
   * @private
   */
  bitDepthFromFmt_() {
    if (this.fmt.audioFormat === 3 && this.fmt.bitsPerSample === 32) {
      this.bitDepth = '32f';
    } else if (this.fmt.audioFormat === 6) {
      this.bitDepth = '8a';
    } else if (this.fmt.audioFormat === 7) {
      this.bitDepth = '8m';
    } else {
      this.bitDepth = this.fmt.bitsPerSample.toString();
    }
  }

  /**
   * Validate the bit depth.
   * @return {boolean} True is the bit depth is valid.
   * @throws {Error} If bit depth is invalid.
   * @private
   */
  validateBitDepth_() {
    if (!this.WAV_AUDIO_FORMATS[this.bitDepth]) {
      if (parseInt(this.bitDepth, 10) > 8 &&
          parseInt(this.bitDepth, 10) < 54) {
        return true;
      }
      throw new Error('Invalid bit depth.');
    }
    return true;
  }

  /**
   * Update the type definition used to read and write the samples.
   * @private
   */
  updateDataType_() {
    this.dataType = {
      bits: ((parseInt(this.bitDepth, 10) - 1) | 7) + 1,
      fp: this.bitDepth == '32f' || this.bitDepth == '64',
      signed: this.bitDepth != '8',
      be: this.container == 'RIFX'
    };
    if (['4', '8a', '8m'].indexOf(this.bitDepth) > -1 ) {
      this.dataType.bits = 8;
      this.dataType.signed = false;
    }
  }

  /**
   * Validate the header of the file.
   * @throws {Error} If bit depth is invalid.
   * @throws {Error} If the number of channels is invalid.
   * @throws {Error} If the sample rate is invalid.
   * @ignore
   * @private
   */
  validateWavHeader_() {
    this.validateBitDepth_();
    if (!validateNumChannels(this.fmt.numChannels, this.fmt.bitsPerSample)) {
      throw new Error('Invalid number of channels.');
    }
    if (!validateSampleRate(
        this.fmt.numChannels, this.fmt.bitsPerSample, this.fmt.sampleRate)) {
      throw new Error('Invalid sample rate.');
    }
  }
}


1			/*
2			* Copyright (c) 2017-2019 Rafael da Silva Rocha.
3			*
4			* Permission is hereby granted, free of charge, to any person obtaining
5			* a copy of this software and associated documentation files (the
6			* "Software"), to deal in the Software without restriction, including
7			* without limitation the rights to use, copy, modify, merge, publish,
8			* distribute, sublicense, and/or sell copies of the Software, and to
9			* permit persons to whom the Software is furnished to do so, subject to
10			* the following conditions:
11			*
12			* The above copyright notice and this permission notice shall be
13			* included in all copies or substantial portions of the Software.
14			*
15			* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16			* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17			* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18			* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
19			* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
20			* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
21			* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22			*
23			*/
24
25			/**
26			* @fileoverview The WaveFileCreator class.
27			* @see https://github.com/rochars/wavefile
28			*/
29
30			/** @module wavefile */
31
32			import WaveFileParser from './wavefile-parser';
33			import interleave from './interleave';
34			import dwChannelMask from './dw-channel-mask';
35			import validateNumChannels from './validate-num-channels';
36			import validateSampleRate from './validate-sample-rate';
37			import {packArrayTo, packTo, unpack} from 'byte-data';
38
39			/**
40			* A class to read, write and create wav files.
41			* @extends WaveFileParser
42			*/
43			export default class WaveFileCreator extends WaveFileParser {
44
45			constructor() {
46			super();
47			/**
48			* The bit depth code according to the samples.
49			* @type {string}
50			*/
51			this.bitDepth = '0';
52			/**
53			* @type {!Object}
54			* @protected
55			*/
56			this.dataType = {};
57			/**
58			* Audio formats.
59			* Formats not listed here should be set to 65534,
60			* the code for WAVE_FORMAT_EXTENSIBLE
61			* @enum {number}
62			* @protected
63			*/
64			this.WAV_AUDIO_FORMATS = {
65			'4': 17,
66			'8': 1,
67			'8a': 6,
68			'8m': 7,
69			'16': 1,
70			'24': 1,
71			'32': 1,
72			'32f': 3,
73			'64': 3
74			};
75			}
76
77			/**
78			* Set up the WaveFileCreator object based on the arguments passed.
79			* Existing chunks are reset.
80			* @param {number} numChannels The number of channels
81			* (Integer numbers: 1 for mono, 2 stereo and so on).
82			* @param {number} sampleRate The sample rate.
83			* Integer numbers like 8000, 44100, 48000, 96000, 192000.
84			* @param {string} bitDepthCode The audio bit depth code.
85			* One of '4', '8', '8a', '8m', '16', '24', '32', '32f', '64'
86			* or any value between '8' and '32' (like '12').
87			* @param {!Array<number>\|!Array<!Array<number>>\|!TypedArray} samples
88			* The samples. Must be in the correct range according to the bit depth.
89			* @param {?Object} options Optional. Used to force the container
90			* as RIFX with {'container': 'RIFX'}
91			* @throws {Error} If any argument does not meet the criteria.
92			*/
93			fromScratch(numChannels, sampleRate, bitDepthCode, samples, options={}) {
94			// reset all chunks
95			this.clearHeaders();
96			this.newWavFile_(numChannels, sampleRate, bitDepthCode, samples, options);
97			}
98
99			/**
100			* Set up the WaveFileCreator object based on the arguments passed.
101			* @param {number} numChannels The number of channels
102			* (Integer numbers: 1 for mono, 2 stereo and so on).
103			* @param {number} sampleRate The sample rate.
104			* Integer numbers like 8000, 44100, 48000, 96000, 192000.
105			* @param {string} bitDepthCode The audio bit depth code.
106			* One of '4', '8', '8a', '8m', '16', '24', '32', '32f', '64'
107			* or any value between '8' and '32' (like '12').
108			* @param {!Array<number>\|!Array<!Array<number>>\|!TypedArray} samples
109			* The samples. Must be in the correct range according to the bit depth.
110			* @param {?Object} options Optional. Used to force the container
111			* as RIFX with {'container': 'RIFX'}
112			* @throws {Error} If any argument does not meet the criteria.
113			* @private
114			*/
115			newWavFile_(numChannels, sampleRate, bitDepthCode, samples, options={}) {
116			if (!options.container) {
117			options.container = 'RIFF';
118			}
119			this.container = options.container;
120			this.bitDepth = bitDepthCode;
121			samples = interleave(samples);
122			this.updateDataType_();
123			/** @type {number} */
124			let numBytes = this.dataType.bits / 8;
125			this.data.samples = new Uint8Array(samples.length * numBytes);
126			packArrayTo(samples, this.dataType, this.data.samples);
127			this.makeWavHeader_(
128			bitDepthCode, numChannels, sampleRate,
129			numBytes, this.data.samples.length, options);
130			this.data.chunkId = 'data';
131			this.data.chunkSize = this.data.samples.length;
132			this.validateWavHeader_();
133			}
134
135			/**
136			* Set up the WaveFileParser object from a byte buffer.
137			* @param {!Uint8Array} wavBuffer The buffer.
138			* @param {boolean=} samples True if the samples should be loaded.
139			* @throws {Error} If container is not RIFF, RIFX or RF64.
140			* @throws {Error} If format is not WAVE.
141			* @throws {Error} If no 'fmt ' chunk is found.
142			* @throws {Error} If no 'data' chunk is found.
143			*/
144			fromBuffer(wavBuffer, samples=true) {
145			super.fromBuffer(wavBuffer, samples);
146			this.bitDepthFromFmt_();
147			this.updateDataType_();
148			}
149
150			/**
151			* Return a byte buffer representig the WaveFileParser object as a .wav file.
152			* The return value of this method can be written straight to disk.
153			* @return {!Uint8Array} A wav file.
154			* @throws {Error} If bit depth is invalid.
155			* @throws {Error} If the number of channels is invalid.
156			* @throws {Error} If the sample rate is invalid.
157			*/
158			toBuffer() {
159			this.validateWavHeader_();
160			return super.toBuffer();
161			}
162
163			/**
164			* Return the sample at a given index.
165			* @param {number} index The sample index.
166			* @return {number} The sample.
167			* @throws {Error} If the sample index is off range.
168			*/
169			getSample(index) {
170			index = index * (this.dataType.bits / 8);
171			if (index + this.dataType.bits / 8 > this.data.samples.length) {
172			throw new Error('Range error');
173			}
174			return unpack(
175			this.data.samples.slice(index, index + this.dataType.bits / 8),
176			this.dataType);
177			}
178
179			/**
180			* Set the sample at a given index.
181			* @param {number} index The sample index.
182			* @param {number} sample The sample.
183			* @throws {Error} If the sample index is off range.
184			*/
185			setSample(index, sample) {
186			index = index * (this.dataType.bits / 8);
187			if (index + this.dataType.bits / 8 > this.data.samples.length) {
188			throw new Error('Range error');
189			}
190			packTo(sample, this.dataType, this.data.samples, index);
191			}
192
193			/**
194			* Define the header of a wav file.
195			* @param {string} bitDepthCode The audio bit depth
196			* @param {number} numChannels The number of channels
197			* @param {number} sampleRate The sample rate.
198			* @param {number} numBytes The number of bytes each sample use.
199			* @param {number} samplesLength The length of the samples in bytes.
200			* @param {!Object} options The extra options, like container defintion.
201			* @private
202			*/
203			makeWavHeader_(
204			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
205			if (bitDepthCode == '4') {
206			this.createADPCMHeader_(
207			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
208
209			} else if (bitDepthCode == '8a' \|\| bitDepthCode == '8m') {
210			this.createALawMulawHeader_(
211			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
212
213			} else if(Object.keys(this.WAV_AUDIO_FORMATS).indexOf(bitDepthCode) == -1 \|\|
214			numChannels > 2) {
215			this.createExtensibleHeader_(
216			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
217
218			} else {
219			this.createPCMHeader_(
220			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
221			}
222			}
223
224			/**
225			* Create the header of a linear PCM wave file.
226			* @param {string} bitDepthCode The audio bit depth
227			* @param {number} numChannels The number of channels
228			* @param {number} sampleRate The sample rate.
229			* @param {number} numBytes The number of bytes each sample use.
230			* @param {number} samplesLength The length of the samples in bytes.
231			* @param {!Object} options The extra options, like container defintion.
232			* @private
233			*/
234			createPCMHeader_(
235			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
236			this.container = options.container;
237			this.chunkSize = 36 + samplesLength;
238			this.format = 'WAVE';
239			this.bitDepth = bitDepthCode;
240			this.fmt = {
241			chunkId: 'fmt ',
242			chunkSize: 16,
243			audioFormat: this.WAV_AUDIO_FORMATS[bitDepthCode] \|\| 65534,
244			numChannels: numChannels,
245			sampleRate: sampleRate,
246			byteRate: (numChannels * numBytes) * sampleRate,
247			blockAlign: numChannels * numBytes,
248			bitsPerSample: parseInt(bitDepthCode, 10),
249			cbSize: 0,
250			validBitsPerSample: 0,
251			dwChannelMask: 0,
252			subformat: []
253			};
254			}
255
256			/**
257			* Create the header of a ADPCM wave file.
258			* @param {string} bitDepthCode The audio bit depth
259			* @param {number} numChannels The number of channels
260			* @param {number} sampleRate The sample rate.
261			* @param {number} numBytes The number of bytes each sample use.
262			* @param {number} samplesLength The length of the samples in bytes.
263			* @param {!Object} options The extra options, like container defintion.
264			* @private
265			*/
266			createADPCMHeader_(
267			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
268			this.createPCMHeader_(
269			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
270			this.chunkSize = 40 + samplesLength;
271			this.fmt.chunkSize = 20;
272			this.fmt.byteRate = 4055;
273			this.fmt.blockAlign = 256;
274			this.fmt.bitsPerSample = 4;
275			this.fmt.cbSize = 2;
276			this.fmt.validBitsPerSample = 505;
277			this.fact = {
278			chunkId: 'fact',
279			chunkSize: 4,
280			dwSampleLength: samplesLength * 2
281			};
282			}
283
284			/**
285			* Create the header of WAVE_FORMAT_EXTENSIBLE file.
286			* @param {string} bitDepthCode The audio bit depth
287			* @param {number} numChannels The number of channels
288			* @param {number} sampleRate The sample rate.
289			* @param {number} numBytes The number of bytes each sample use.
290			* @param {number} samplesLength The length of the samples in bytes.
291			* @param {!Object} options The extra options, like container defintion.
292			* @private
293			*/
294			createExtensibleHeader_(
295			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
296			this.createPCMHeader_(
297			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
298			this.chunkSize = 36 + 24 + samplesLength;
299			this.fmt.chunkSize = 40;
300			this.fmt.bitsPerSample = ((parseInt(bitDepthCode, 10) - 1) \| 7) + 1;
301			this.fmt.cbSize = 22;
302			this.fmt.validBitsPerSample = parseInt(bitDepthCode, 10);
303			this.fmt.dwChannelMask = dwChannelMask(numChannels);
304			// subformat 128-bit GUID as 4 32-bit values
305			// only supports uncompressed integer PCM samples
306			this.fmt.subformat = [1, 1048576, 2852126848, 1905997824];
307			}
308
309			/**
310			* Create the header of mu-Law and A-Law wave files.
311			* @param {string} bitDepthCode The audio bit depth
312			* @param {number} numChannels The number of channels
313			* @param {number} sampleRate The sample rate.
314			* @param {number} numBytes The number of bytes each sample use.
315			* @param {number} samplesLength The length of the samples in bytes.
316			* @param {!Object} options The extra options, like container defintion.
317			* @private
318			*/
319			createALawMulawHeader_(
320			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options) {
321			this.createPCMHeader_(
322			bitDepthCode, numChannels, sampleRate, numBytes, samplesLength, options);
323			this.chunkSize = 40 + samplesLength;
324			this.fmt.chunkSize = 20;
325			this.fmt.cbSize = 2;
326			this.fmt.validBitsPerSample = 8;
327			this.fact = {
328			chunkId: 'fact',
329			chunkSize: 4,
330			dwSampleLength: samplesLength
331			};
332			}
333
334			/**
335			* Set the string code of the bit depth based on the 'fmt ' chunk.
336			* @private
337			*/
338			bitDepthFromFmt_() {
339			if (this.fmt.audioFormat === 3 && this.fmt.bitsPerSample === 32) {
340			this.bitDepth = '32f';
341			} else if (this.fmt.audioFormat === 6) {
342			this.bitDepth = '8a';
343			} else if (this.fmt.audioFormat === 7) {
344			this.bitDepth = '8m';
345			} else {
346			this.bitDepth = this.fmt.bitsPerSample.toString();
347			}
348			}
349
350			/**
351			* Validate the bit depth.
352			* @return {boolean} True is the bit depth is valid.
353			* @throws {Error} If bit depth is invalid.
354			* @private
355			*/
356			validateBitDepth_() {
357			if (!this.WAV_AUDIO_FORMATS[this.bitDepth]) {
358			if (parseInt(this.bitDepth, 10) > 8 &&
359			parseInt(this.bitDepth, 10) < 54) {
360			return true;
361			}
362			throw new Error('Invalid bit depth.');
363			}
364			return true;
365			}
366
367			/**
368			* Update the type definition used to read and write the samples.
369			* @private
370			*/
371			updateDataType_() {
372			this.dataType = {
373			bits: ((parseInt(this.bitDepth, 10) - 1) \| 7) + 1,
374			fp: this.bitDepth == '32f' \|\| this.bitDepth == '64',
375			signed: this.bitDepth != '8',
376			be: this.container == 'RIFX'
377			};
378			if (['4', '8a', '8m'].indexOf(this.bitDepth) > -1 ) {
379			this.dataType.bits = 8;
380			this.dataType.signed = false;
381			}
382			}
383
384			/**
385			* Validate the header of the file.
386			* @throws {Error} If bit depth is invalid.
387			* @throws {Error} If the number of channels is invalid.
388			* @throws {Error} If the sample rate is invalid.
389			* @ignore
390			* @private
391			*/
392			validateWavHeader_() {
393			this.validateBitDepth_();
394			if (!validateNumChannels(this.fmt.numChannels, this.fmt.bitsPerSample)) {
395			throw new Error('Invalid number of channels.');
396			}
397			if (!validateSampleRate(
398			this.fmt.numChannels, this.fmt.bitsPerSample, this.fmt.sampleRate)) {
399			throw new Error('Invalid sample rate.');
400			}
401			}
402			}
403

rochars / wavefile

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WaveFileCreator.createALawMulawHeader_ A

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