wavefile-converter.js ➔ outputSize_ - Code Metrics - Inspection of "Rollback clamp int overflows to not break the API" - rochars/wavefile - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 4f3f4b...826326 )

by Rafael S.

created 2020-01-27 09:04 UTC

wavefile-converter.js ➔ outputSize_ A

↳ Parent: lib/wavefile-converter.js

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Total Lines	8
Code Lines	5

Duplication

Lines	0
Ratio	0 %

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cc	2
eloc	5
dl	0
loc	8
rs	10
c	0
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/*
 * 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 WaveFileConverter class.
 * @see https://github.com/rochars/wavefile
 */

import { changeBitDepth } from 'bitdepth';
import * as imaadpcm from 'imaadpcm';
import * as alawmulaw from 'alawmulaw';
import { unpackArrayTo } from 'byte-data';
import { WaveFileCueEditor } from './wavefile-cue-editor';
import { validateSampleRate } from './validators/validate-sample-rate';
import { resample } from './resampler';

/**
 * A class to convert wav files to other types of wav files.
 * @extends WaveFileCueEditor
 * @ignore
 */
export class WaveFileConverter extends WaveFileCueEditor {

  /**
   * Force a file as RIFF.
   */
  toRIFF() {
    /** @type {!Float64Array} */
    let output = new Float64Array(
      outputSize_(this.data.samples.length, this.dataType.bits / 8));
    unpackArrayTo(this.data.samples, this.dataType, output,
      0, this.data.samples.length, false, false);
    this.fromExisting_(
      this.fmt.numChannels,
      this.fmt.sampleRate,
      this.bitDepth,
      output);
  }

  /**
   * Force a file as RIFX.
   */
  toRIFX() {
    /** @type {!Float64Array} */
    let output = new Float64Array(
      outputSize_(this.data.samples.length, this.dataType.bits / 8));
    unpackArrayTo(this.data.samples, this.dataType, output,
      0, this.data.samples.length, false, false);
    this.fromExisting_(
      this.fmt.numChannels,
      this.fmt.sampleRate,
      this.bitDepth,
      output,
      {container: 'RIFX'});
  }

  /**
   * Encode a 16-bit wave file as 4-bit IMA ADPCM.
   * @throws {Error} If sample rate is not 8000.
   * @throws {Error} If number of channels is not 1.
   */
  toIMAADPCM() {
    if (this.fmt.sampleRate !== 8000) {
      throw new Error(
        'Only 8000 Hz files can be compressed as IMA-ADPCM.');
    } else if (this.fmt.numChannels !== 1) {
      throw new Error(
        'Only mono files can be compressed as IMA-ADPCM.');
    } else {
      this.assure16Bit_();
      /** @type {!Int16Array} */
      let output = new Int16Array(
        outputSize_(this.data.samples.length, 2));
      unpackArrayTo(this.data.samples, this.dataType, output,
        0, this.data.samples.length, false, false);
      this.fromExisting_(
        this.fmt.numChannels,
        this.fmt.sampleRate,
        '4',
        imaadpcm.encode(output),
        {container: this.correctContainer_()});
    }
  }

  /**
   * Decode a 4-bit IMA ADPCM wave file as a 16-bit wave file.
   * @param {string} bitDepthCode The new bit depth of the samples.
   *    One of '8' ... '32' (integers), '32f' or '64' (floats).
   *    Optional. Default is 16.
   */
  fromIMAADPCM(bitDepthCode='16') {
    this.fromExisting_(
      this.fmt.numChannels,
      this.fmt.sampleRate,
      '16',
      imaadpcm.decode(this.data.samples, this.fmt.blockAlign),
      {container: this.correctContainer_()});
    if (bitDepthCode != '16') {
      this.toBitDepth(bitDepthCode);
    }
  }

  /**
   * Encode a 16-bit wave file as 8-bit A-Law.
   */
  toALaw() {
    this.assure16Bit_();
    /** @type {!Int16Array} */
    let output = new Int16Array(
      outputSize_(this.data.samples.length, 2));
    unpackArrayTo(this.data.samples, this.dataType, output,
        0, this.data.samples.length, false, false);
    this.fromExisting_(
      this.fmt.numChannels,
      this.fmt.sampleRate,
      '8a',
      alawmulaw.alaw.encode(output),
      {container: this.correctContainer_()});
  }

  /**
   * Decode a 8-bit A-Law wave file into a 16-bit wave file.
   * @param {string} bitDepthCode The new bit depth of the samples.
   *    One of '8' ... '32' (integers), '32f' or '64' (floats).
   *    Optional. Default is 16.
   */
  fromALaw(bitDepthCode='16') {
    this.fromExisting_(
      this.fmt.numChannels,
      this.fmt.sampleRate,
      '16',
      alawmulaw.alaw.decode(this.data.samples),
      {container: this.correctContainer_()});
    if (bitDepthCode != '16') {
      this.toBitDepth(bitDepthCode);
    }
  }

  /**
   * Encode 16-bit wave file as 8-bit mu-Law.
   */
  toMuLaw() {
    this.assure16Bit_();
    /** @type {!Int16Array} */
    let output = new Int16Array(
      outputSize_(this.data.samples.length, 2));
    unpackArrayTo(this.data.samples, this.dataType, output,
        0, this.data.samples.length, false, false);
    this.fromExisting_(
      this.fmt.numChannels,
      this.fmt.sampleRate,
      '8m',
      alawmulaw.mulaw.encode(output),
      {container: this.correctContainer_()});
  }

  /**
   * Decode a 8-bit mu-Law wave file into a 16-bit wave file.
   * @param {string} bitDepthCode The new bit depth of the samples.
   *    One of '8' ... '32' (integers), '32f' or '64' (floats).
   *    Optional. Default is 16.
   */
  fromMuLaw(bitDepthCode='16') {
    this.fromExisting_(
      this.fmt.numChannels,
      this.fmt.sampleRate,
      '16',
      alawmulaw.mulaw.decode(this.data.samples),
      {container: this.correctContainer_()});
    if (bitDepthCode != '16') {
      this.toBitDepth(bitDepthCode);
    }
  }

  /**
   * Change the bit depth of the samples.
   * @param {string} newBitDepth The new bit depth of the samples.
   *    One of '8' ... '32' (integers), '32f' or '64' (floats)
   * @param {boolean} changeResolution A boolean indicating if the
   *    resolution of samples should be actually changed or not.
   * @throws {Error} If the bit depth is not valid.
   */
  toBitDepth(newBitDepth, changeResolution=true) {
    /** @type {string} */
    let toBitDepth = newBitDepth;
    /** @type {string} */
    let thisBitDepth = this.bitDepth;
    if (!changeResolution) {
      if (newBitDepth != '32f') {
        toBitDepth = this.dataType.bits.toString();
      }
      thisBitDepth = '' + this.dataType.bits;
    }
    // If the file is compressed, make it
    // PCM before changing the bit depth
    this.assureUncompressed_();
    /**
     * The original samples, interleaved.
     * @type {!Array|!TypedArray}
     */
    let samples = this.getSamples(true);
    /**
     * The container for the new samples.
     * @type {!Float64Array}
     */
    let newSamples = new Float64Array(samples.length);
    // Change the bit depth
    changeBitDepth(samples, thisBitDepth, newSamples, toBitDepth);
    // Re-create the file
    this.fromExisting_(
      this.fmt.numChannels,
      this.fmt.sampleRate,
      newBitDepth,
      newSamples,
      {container: this.correctContainer_()});
  }

  /**
   * Convert the sample rate of the file.
   * @param {number} sampleRate The target sample rate.
   * @param {?Object} details The extra configuration, if needed.
   */
  toSampleRate(sampleRate, details={}) {
    this.validateResample_(sampleRate);
    /** @type {!Array|!TypedArray} */
    let samples = this.getSamples();
    /** @type {!Array|!Float64Array} */
    let newSamples = [];
    // Mono files
    if (samples.constructor === Float64Array) {
      newSamples = resample(samples, this.fmt.sampleRate, sampleRate, details);
    // Multi-channel files
    } else {
      for (let i = 0; i < samples.length; i++) {
        newSamples.push(resample(
          samples[i], this.fmt.sampleRate, sampleRate, details));
      }
    }
    // Truncate samples
    if (this.bitDepth !== '64' && this.bitDepth !== '32f') {
      // Truncate samples in mono files
      if (newSamples[0].constructor === Number) {
        truncateIntSamples(newSamples, this.dataType.bits);
      // Truncate samples in multi-channel files
      } else {
        for (let i = 0; i < newSamples.length; i++) {
          truncateIntSamples(newSamples[i], this.dataType.bits);
        }
      }
    }
    // Recreate the file
    this.fromExisting_(
      this.fmt.numChannels, sampleRate, this.bitDepth, newSamples,
      {'container': this.correctContainer_()});
  }

  /**
   * Validate the conditions for resampling.
   * @param {number} sampleRate The target sample rate.
   * @throws {Error} If the file cant be resampled.
   * @private
   */
  validateResample_(sampleRate) {
    if (!validateSampleRate(
        this.fmt.numChannels, this.fmt.bitsPerSample, sampleRate)) {
      throw new Error('Invalid sample rate.');
    } else if (['4','8a','8m'].indexOf(this.bitDepth) > -1) {
      throw new Error(
        'wavefile can\'t change the sample rate of compressed files.');
    }
  }

  /**
   * Make the file 16-bit if it is not.
   * @private
   */
  assure16Bit_() {
    this.assureUncompressed_();
    if (this.bitDepth != '16') {
      this.toBitDepth('16');
    }
  }

  /**
   * Uncompress the samples in case of a compressed file.
   * @private
   */
  assureUncompressed_() {
    if (this.bitDepth == '8a') {
      this.fromALaw();
    } else if (this.bitDepth == '8m') {
      this.fromMuLaw();
    } else if (this.bitDepth == '4') {
      this.fromIMAADPCM();
    }
  }

  /**
   * Return 'RIFF' if the container is 'RF64', the current container name
   * otherwise. Used to enforce 'RIFF' when RF64 is not allowed.
   * @return {string}
   * @private
   */
  correctContainer_() {
    return this.container == 'RF64' ? 'RIFF' : this.container;
  }

  /**
   * Set up the WaveFileCreator object based on the arguments passed.
   * This method only reset the fmt , fact, ds64 and data chunks.
   * @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|!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
   */
  fromExisting_(numChannels, sampleRate, bitDepthCode, samples, options={}) {
    let tmpWav = new WaveFileCueEditor();
    Object.assign(this.fmt, tmpWav.fmt);
    Object.assign(this.fact, tmpWav.fact);
    Object.assign(this.ds64, tmpWav.ds64);
    Object.assign(this.data, tmpWav.data);
    this.newWavFile_(numChannels, sampleRate, bitDepthCode, samples, options);
  }
}

/**
 * Return the size in bytes of the output sample array when applying
 * compression to 16-bit samples.
 * @return {number}
 * @private
 */
function outputSize_(byteLen, byteOffset) {
  /** @type {number} */
  let outputSize = byteLen / byteOffset;
  if (outputSize % 2) {
    outputSize++;
  }
  return outputSize;
}

/**
 * Clamp integer samples.
 * @param {!(Array<number>|TypedArray)} samples The samples to round.
 * @param {number} bits The number of bits.
 * @private
 */
function truncateIntSamples(samples, bits) {
  let max = bits === 8 ? 255 : Math.pow(2, bits) / 2 - 1;
  let min = bits === 8 ? 0 : -max - 1;
  for (let i = 0, len = samples.length; i < len; i++) {
    samples[i] = Math.round(samples[i]);
    if (samples[i] > max) {
      samples[i] = max;
    } else if (samples[i] < min) {
      samples[i] = min;
    }
  }
}


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 WaveFileConverter class.
27			* @see https://github.com/rochars/wavefile
28			*/
29
30			import { changeBitDepth } from 'bitdepth';
31			import * as imaadpcm from 'imaadpcm';
32			import * as alawmulaw from 'alawmulaw';
33			import { unpackArrayTo } from 'byte-data';
34			import { WaveFileCueEditor } from './wavefile-cue-editor';
35			import { validateSampleRate } from './validators/validate-sample-rate';
36			import { resample } from './resampler';
37
38			/**
39			* A class to convert wav files to other types of wav files.
40			* @extends WaveFileCueEditor
41			* @ignore
42			*/
43			export class WaveFileConverter extends WaveFileCueEditor {
44
45			/**
46			* Force a file as RIFF.
47			*/
48			toRIFF() {
49			/** @type {!Float64Array} */
50			let output = new Float64Array(
51			outputSize_(this.data.samples.length, this.dataType.bits / 8));
52			unpackArrayTo(this.data.samples, this.dataType, output,
53			0, this.data.samples.length, false, false);
54			this.fromExisting_(
55			this.fmt.numChannels,
56			this.fmt.sampleRate,
57			this.bitDepth,
58			output);
59			}
60
61			/**
62			* Force a file as RIFX.
63			*/
64			toRIFX() {
65			/** @type {!Float64Array} */
66			let output = new Float64Array(
67			outputSize_(this.data.samples.length, this.dataType.bits / 8));
68			unpackArrayTo(this.data.samples, this.dataType, output,
69			0, this.data.samples.length, false, false);
70			this.fromExisting_(
71			this.fmt.numChannels,
72			this.fmt.sampleRate,
73			this.bitDepth,
74			output,
75			{container: 'RIFX'});
76			}
77
78			/**
79			* Encode a 16-bit wave file as 4-bit IMA ADPCM.
80			* @throws {Error} If sample rate is not 8000.
81			* @throws {Error} If number of channels is not 1.
82			*/
83			toIMAADPCM() {
84			if (this.fmt.sampleRate !== 8000) {
85			throw new Error(
86			'Only 8000 Hz files can be compressed as IMA-ADPCM.');
87			} else if (this.fmt.numChannels !== 1) {
88			throw new Error(
89			'Only mono files can be compressed as IMA-ADPCM.');
90			} else {
91			this.assure16Bit_();
92			/** @type {!Int16Array} */
93			let output = new Int16Array(
94			outputSize_(this.data.samples.length, 2));
95			unpackArrayTo(this.data.samples, this.dataType, output,
96			0, this.data.samples.length, false, false);
97			this.fromExisting_(
98			this.fmt.numChannels,
99			this.fmt.sampleRate,
100			'4',
101			imaadpcm.encode(output),
102			{container: this.correctContainer_()});
103			}
104			}
105
106			/**
107			* Decode a 4-bit IMA ADPCM wave file as a 16-bit wave file.
108			* @param {string} bitDepthCode The new bit depth of the samples.
109			* One of '8' ... '32' (integers), '32f' or '64' (floats).
110			* Optional. Default is 16.
111			*/
112			fromIMAADPCM(bitDepthCode='16') {
113			this.fromExisting_(
114			this.fmt.numChannels,
115			this.fmt.sampleRate,
116			'16',
117			imaadpcm.decode(this.data.samples, this.fmt.blockAlign),
118			{container: this.correctContainer_()});
119			if (bitDepthCode != '16') {
120			this.toBitDepth(bitDepthCode);
121			}
122			}
123
124			/**
125			* Encode a 16-bit wave file as 8-bit A-Law.
126			*/
127			toALaw() {
128			this.assure16Bit_();
129			/** @type {!Int16Array} */
130			let output = new Int16Array(
131			outputSize_(this.data.samples.length, 2));
132			unpackArrayTo(this.data.samples, this.dataType, output,
133			0, this.data.samples.length, false, false);
134			this.fromExisting_(
135			this.fmt.numChannels,
136			this.fmt.sampleRate,
137			'8a',
138			alawmulaw.alaw.encode(output),
139			{container: this.correctContainer_()});
140			}
141
142			/**
143			* Decode a 8-bit A-Law wave file into a 16-bit wave file.
144			* @param {string} bitDepthCode The new bit depth of the samples.
145			* One of '8' ... '32' (integers), '32f' or '64' (floats).
146			* Optional. Default is 16.
147			*/
148			fromALaw(bitDepthCode='16') {
149			this.fromExisting_(
150			this.fmt.numChannels,
151			this.fmt.sampleRate,
152			'16',
153			alawmulaw.alaw.decode(this.data.samples),
154			{container: this.correctContainer_()});
155			if (bitDepthCode != '16') {
156			this.toBitDepth(bitDepthCode);
157			}
158			}
159
160			/**
161			* Encode 16-bit wave file as 8-bit mu-Law.
162			*/
163			toMuLaw() {
164			this.assure16Bit_();
165			/** @type {!Int16Array} */
166			let output = new Int16Array(
167			outputSize_(this.data.samples.length, 2));
168			unpackArrayTo(this.data.samples, this.dataType, output,
169			0, this.data.samples.length, false, false);
170			this.fromExisting_(
171			this.fmt.numChannels,
172			this.fmt.sampleRate,
173			'8m',
174			alawmulaw.mulaw.encode(output),
175			{container: this.correctContainer_()});
176			}
177
178			/**
179			* Decode a 8-bit mu-Law wave file into a 16-bit wave file.
180			* @param {string} bitDepthCode The new bit depth of the samples.
181			* One of '8' ... '32' (integers), '32f' or '64' (floats).
182			* Optional. Default is 16.
183			*/
184			fromMuLaw(bitDepthCode='16') {
185			this.fromExisting_(
186			this.fmt.numChannels,
187			this.fmt.sampleRate,
188			'16',
189			alawmulaw.mulaw.decode(this.data.samples),
190			{container: this.correctContainer_()});
191			if (bitDepthCode != '16') {
192			this.toBitDepth(bitDepthCode);
193			}
194			}
195
196			/**
197			* Change the bit depth of the samples.
198			* @param {string} newBitDepth The new bit depth of the samples.
199			* One of '8' ... '32' (integers), '32f' or '64' (floats)
200			* @param {boolean} changeResolution A boolean indicating if the
201			* resolution of samples should be actually changed or not.
202			* @throws {Error} If the bit depth is not valid.
203			*/
204			toBitDepth(newBitDepth, changeResolution=true) {
205			/** @type {string} */
206			let toBitDepth = newBitDepth;
207			/** @type {string} */
208			let thisBitDepth = this.bitDepth;
209			if (!changeResolution) {
210			if (newBitDepth != '32f') {
211			toBitDepth = this.dataType.bits.toString();
212			}
213			thisBitDepth = '' + this.dataType.bits;
214			}
215			// If the file is compressed, make it
216			// PCM before changing the bit depth
217			this.assureUncompressed_();
218			/**
219			* The original samples, interleaved.
220			* @type {!Array\|!TypedArray}
221			*/
222			let samples = this.getSamples(true);
223			/**
224			* The container for the new samples.
225			* @type {!Float64Array}
226			*/
227			let newSamples = new Float64Array(samples.length);
228			// Change the bit depth
229			changeBitDepth(samples, thisBitDepth, newSamples, toBitDepth);
230			// Re-create the file
231			this.fromExisting_(
232			this.fmt.numChannels,
233			this.fmt.sampleRate,
234			newBitDepth,
235			newSamples,
236			{container: this.correctContainer_()});
237			}
238
239			/**
240			* Convert the sample rate of the file.
241			* @param {number} sampleRate The target sample rate.
242			* @param {?Object} details The extra configuration, if needed.
243			*/
244			toSampleRate(sampleRate, details={}) {
245			this.validateResample_(sampleRate);
246			/** @type {!Array\|!TypedArray} */
247			let samples = this.getSamples();
248			/** @type {!Array\|!Float64Array} */
249			let newSamples = [];
250			// Mono files
251			if (samples.constructor === Float64Array) {
252			newSamples = resample(samples, this.fmt.sampleRate, sampleRate, details);
253			// Multi-channel files
254			} else {
255			for (let i = 0; i < samples.length; i++) {
256			newSamples.push(resample(
257			samples[i], this.fmt.sampleRate, sampleRate, details));
258			}
259			}
260			// Truncate samples
261			if (this.bitDepth !== '64' && this.bitDepth !== '32f') {
262			// Truncate samples in mono files
263			if (newSamples[0].constructor === Number) {
264			truncateIntSamples(newSamples, this.dataType.bits);
265			// Truncate samples in multi-channel files
266			} else {
267			for (let i = 0; i < newSamples.length; i++) {
268			truncateIntSamples(newSamples[i], this.dataType.bits);
269			}
270			}
271			}
272			// Recreate the file
273			this.fromExisting_(
274			this.fmt.numChannels, sampleRate, this.bitDepth, newSamples,
275			{'container': this.correctContainer_()});
276			}
277
278			/**
279			* Validate the conditions for resampling.
280			* @param {number} sampleRate The target sample rate.
281			* @throws {Error} If the file cant be resampled.
282			* @private
283			*/
284			validateResample_(sampleRate) {
285			if (!validateSampleRate(
286			this.fmt.numChannels, this.fmt.bitsPerSample, sampleRate)) {
287			throw new Error('Invalid sample rate.');
288			} else if (['4','8a','8m'].indexOf(this.bitDepth) > -1) {
289			throw new Error(
290			'wavefile can\'t change the sample rate of compressed files.');
291			}
292			}
293
294			/**
295			* Make the file 16-bit if it is not.
296			* @private
297			*/
298			assure16Bit_() {
299			this.assureUncompressed_();
300			if (this.bitDepth != '16') {
301			this.toBitDepth('16');
302			}
303			}
304
305			/**
306			* Uncompress the samples in case of a compressed file.
307			* @private
308			*/
309			assureUncompressed_() {
310			if (this.bitDepth == '8a') {
311			this.fromALaw();
312			} else if (this.bitDepth == '8m') {
313			this.fromMuLaw();
314			} else if (this.bitDepth == '4') {
315			this.fromIMAADPCM();
316			}
317			}
318
319			/**
320			* Return 'RIFF' if the container is 'RF64', the current container name
321			* otherwise. Used to enforce 'RIFF' when RF64 is not allowed.
322			* @return {string}
323			* @private
324			*/
325			correctContainer_() {
326			return this.container == 'RF64' ? 'RIFF' : this.container;
327			}
328
329			/**
330			* Set up the WaveFileCreator object based on the arguments passed.
331			* This method only reset the fmt , fact, ds64 and data chunks.
332			* @param {number} numChannels The number of channels
333			* (Integer numbers: 1 for mono, 2 stereo and so on).
334			* @param {number} sampleRate The sample rate.
335			* Integer numbers like 8000, 44100, 48000, 96000, 192000.
336			* @param {string} bitDepthCode The audio bit depth code.
337			* One of '4', '8', '8a', '8m', '16', '24', '32', '32f', '64'
338			* or any value between '8' and '32' (like '12').
339			* @param {!Array\|!TypedArray} samples
340			* The samples. Must be in the correct range according to the bit depth.
341			* @param {?Object} options Optional. Used to force the container
342			* as RIFX with {'container': 'RIFX'}
343			* @throws {Error} If any argument does not meet the criteria.
344			* @private
345			*/
346			fromExisting_(numChannels, sampleRate, bitDepthCode, samples, options={}) {
347			let tmpWav = new WaveFileCueEditor();
348			Object.assign(this.fmt, tmpWav.fmt);
349			Object.assign(this.fact, tmpWav.fact);
350			Object.assign(this.ds64, tmpWav.ds64);
351			Object.assign(this.data, tmpWav.data);
352			this.newWavFile_(numChannels, sampleRate, bitDepthCode, samples, options);
353			}
354			}
355
356			/**
357			* Return the size in bytes of the output sample array when applying
358			* compression to 16-bit samples.
359			* @return {number}
360			* @private
361			*/
362			function outputSize_(byteLen, byteOffset) {
363			/** @type {number} */
364			let outputSize = byteLen / byteOffset;
365			if (outputSize % 2) {
366			outputSize++;
367			}
368			return outputSize;
369			}
370
371			/**
372			* Clamp integer samples.
373			* @param {!(Array<number>\|TypedArray)} samples The samples to round.
374			* @param {number} bits The number of bits.
375			* @private
376			*/
377			function truncateIntSamples(samples, bits) {
378			let max = bits === 8 ? 255 : Math.pow(2, bits) / 2 - 1;
379			let min = bits === 8 ? 0 : -max - 1;
380			for (let i = 0, len = samples.length; i < len; i++) {
381			samples[i] = Math.round(samples[i]);
382			if (samples[i] > max) {
383			samples[i] = max;
384			} else if (samples[i] < min) {
385			samples[i] = min;
386			}
387			}
388			}
389

rochars / wavefile

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wavefile-converter.js ➔ outputSize_ A

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