RIFFFile.getSubChunkIndex_ - Code Metrics - Inspection of "Move readZSTR() method do WaveFileReader class" - rochars/wavefile - Measure and Improve Code Quality continuously with Scrutinizer

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by Rafael S.

created 2019-08-08 13:43 UTC

RIFFFile.getSubChunkIndex_ A

↳ Parent: RIFFFile

Complexity

Conditions

Size

Total Lines	22
Code Lines	16

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	3
eloc	16
dl	0
loc	22
rs	9.6
c	0
b	0
f	0

/*
 * 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 RIFFFile class.
 * @see https://github.com/rochars/wavefile
 */

/** @module wavefile */

import {unpackString, unpack} from 'byte-data';

/**
 * A class to perform low-level reading of RIFF/RIFX files.
 */
export default class RIFFFile {

  constructor() {
    
    /** @type {number} */
    this.head_ = 0;
    /** @type {!Object} */
    this.uInt32_ = {bits: 32, be: false};
    /** @type {!Object} */
    this.uInt16_ = {bits: 16, be: false};
    /**
     * The container identifier.
     * 'RIFF', 'RIFX' and 'RF64' are supported.
     * @type {string}
     */
    this.container = '';
    /**
     * @type {number}
     */
    this.chunkSize = 0;
    /**
     * The format.
     * @type {string}
     */
    this.format = '';
    /**
     * A object defining the start and end of all chunks in a wav buffer.
     * @type {!Object}
     */
    this.signature = {};
  }

  /**
   * Read the signature of the chunks in a RIFF/RIFX file.
   * @param {!Uint8Array} buffer The file bytes.
   * @protected
   */
  setSignature(buffer) {
      this.head_ = 0;
      /** @type {string} */
      let chunkId = this.getChunkId_(buffer, 0);
      this.uInt32_.be = chunkId == 'RIFX';
      /** @type {string} */
      let format = unpackString(buffer, 8, 12);
      this.head_ += 4;
      this.signature = {
          chunkId: chunkId,
          chunkSize: this.getChunkSize_(buffer, 0),
          format: format,
          subChunks: this.getSubChunksIndex_(buffer)
      };
  }

  /**
    * Find a chunk by its fourCC_ in a array of RIFF chunks.
    * @param {string} chunkId The chunk fourCC_.
    * @param {boolean} multiple True if there may be multiple chunks
    *    with the same chunkId.
    * @return {Object}
    * @protected
    */
  findChunk(chunkId, multiple=false) {
    /** @type {!Array<!Object>} */
    let chunks = this.signature.subChunks;
    /** @type {!Array<!Object>} */
    let chunk = [];
    for (let i=0; i<chunks.length; i++) {
      if (chunks[i].chunkId == chunkId) {
        if (multiple) {
          chunk.push(chunks[i]);
        } else {
          return chunks[i];
        }
      }
    }
    if (chunkId == 'LIST') {
      return chunk.length ? chunk : null;
    }
    return null;
  }

  /**
   * Read the main chunk of a RIFF file.
   * @param {!Uint8Array} bytes A RIFF file buffer.
   * @throws {Error} If container is not RIFF, RIFX or RF64.
   * @protected
   */
  readRIFFChunk(bytes) {
    this.head_ = 0;
    this.container = this.readString(bytes, 4);
    if (['RIFF', 'RIFX', 'RF64'].indexOf(this.container) === -1) {
      throw Error('Not a supported format.');
    }
    this.uInt16_.be = this.container === 'RIFX';
    this.uInt32_.be = this.uInt16_.be;
    this.chunkSize = this.readNumber(bytes, this.uInt32_);
    this.format = this.readString(bytes, 4);
  }

  /**
   * Read bytes as a string from a RIFF chunk.
   * @param {!Uint8Array} bytes The bytes.
   * @param {number} maxSize the max size of the string.
   * @return {string} The string.
   * @protected
   */
  readString(bytes, maxSize) {
    /** @type {string} */
    let str = '';
    str = unpackString(bytes, this.head_, this.head_ + maxSize);
    this.head_ += maxSize;
    return str;
  }

  /**
   * Read a number from a chunk.
   * @param {!Uint8Array} bytes The chunk bytes.
   * @param {!Object} bdType The type definition.
   * @return {number} The number.
   * @protected
   */
  readNumber(bytes, bdType) {
    /** @type {number} */
    let size = bdType.bits / 8;
    /** @type {number} */
    let value = unpack(bytes, bdType, this.head_);
    this.head_ += size;
    return value;
  }

  /**
   * Return the sub chunks of a RIFF file.
   * @param {!Uint8Array} buffer the RIFF file bytes.
   * @return {!Array<Object>} The subchunks of a RIFF/RIFX or LIST chunk.
   * @private
   */
  getSubChunksIndex_(buffer) {
      /** @type {!Array<!Object>} */
      let chunks = [];
      /** @type {number} */
      let i = this.head_;
      while(i <= buffer.length - 8) {
          chunks.push(this.getSubChunkIndex_(buffer, i));
          i += 8 + chunks[chunks.length - 1].chunkSize;
          i = i % 2 ? i + 1 : i;
      }
      return chunks;
  }

  /**
   * Return a sub chunk from a RIFF file.
   * @param {!Uint8Array} buffer the RIFF file bytes.
   * @param {number} index The start index of the chunk.
   * @return {!Object} A subchunk of a RIFF/RIFX or LIST chunk.
   * @private
   */
  getSubChunkIndex_(buffer, index) {
      /** @type {!Object} */
      let chunk = {
          chunkId: this.getChunkId_(buffer, index),
          chunkSize: this.getChunkSize_(buffer, index),
      };
      if (chunk.chunkId == 'LIST') {
          chunk.format = unpackString(buffer, index + 8, index + 12);
          this.head_ += 4;
          chunk.subChunks = this.getSubChunksIndex_(buffer);
      } else {
          /** @type {number} */
          let realChunkSize = chunk.chunkSize % 2 ?
              chunk.chunkSize + 1 : chunk.chunkSize;
          this.head_ = index + 8 + realChunkSize;
          chunk.chunkData = {
              start: index + 8,
              end: this.head_
          };
      }
      return chunk;
  }

  /**
   * Return the fourCC_ of a chunk.
   * @param {!Uint8Array} buffer the RIFF file bytes.
   * @param {number} index The start index of the chunk.
   * @return {string} The id of the chunk.
   * @private
   */
  getChunkId_(buffer, index) {
      this.head_ += 4;
      return unpackString(buffer, index, index + 4);
  }

  /**
   * Return the size of a chunk.
   * @param {!Uint8Array} buffer the RIFF file bytes.
   * @param {number} index The start index of the chunk.
   * @return {number} The size of the chunk without the id and size fields.
   * @private
   */
  getChunkSize_(buffer, index) {
      this.head_ += 4;
      return unpack(buffer, this.uInt32_, index + 4);
  }
}


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 RIFFFile class.
27			* @see https://github.com/rochars/wavefile
28			*/
29
30			/** @module wavefile */
31
32			import {unpackString, unpack} from 'byte-data';
33
34			/**
35			* A class to perform low-level reading of RIFF/RIFX files.
36			*/
37			export default class RIFFFile {
38
39			constructor() {
40
41			/** @type {number} */
42			this.head_ = 0;
43			/** @type {!Object} */
44			this.uInt32_ = {bits: 32, be: false};
45			/** @type {!Object} */
46			this.uInt16_ = {bits: 16, be: false};
47			/**
48			* The container identifier.
49			* 'RIFF', 'RIFX' and 'RF64' are supported.
50			* @type {string}
51			*/
52			this.container = '';
53			/**
54			* @type {number}
55			*/
56			this.chunkSize = 0;
57			/**
58			* The format.
59			* @type {string}
60			*/
61			this.format = '';
62			/**
63			* A object defining the start and end of all chunks in a wav buffer.
64			* @type {!Object}
65			*/
66			this.signature = {};
67			}
68
69			/**
70			* Read the signature of the chunks in a RIFF/RIFX file.
71			* @param {!Uint8Array} buffer The file bytes.
72			* @protected
73			*/
74			setSignature(buffer) {
75			this.head_ = 0;
76			/** @type {string} */
77			let chunkId = this.getChunkId_(buffer, 0);
78			this.uInt32_.be = chunkId == 'RIFX';
79			/** @type {string} */
80			let format = unpackString(buffer, 8, 12);
81			this.head_ += 4;
82			this.signature = {
83			chunkId: chunkId,
84			chunkSize: this.getChunkSize_(buffer, 0),
85			format: format,
86			subChunks: this.getSubChunksIndex_(buffer)
87			};
88			}
89
90			/**
91			* Find a chunk by its fourCC_ in a array of RIFF chunks.
92			* @param {string} chunkId The chunk fourCC_.
93			* @param {boolean} multiple True if there may be multiple chunks
94			* with the same chunkId.
95			* @return {Object}
96			* @protected
97			*/
98			findChunk(chunkId, multiple=false) {
99			/** @type {!Array<!Object>} */
100			let chunks = this.signature.subChunks;
101			/** @type {!Array<!Object>} */
102			let chunk = [];
103			for (let i=0; i<chunks.length; i++) {
104			if (chunks[i].chunkId == chunkId) {
105			if (multiple) {
106			chunk.push(chunks[i]);
107			} else {
108			return chunks[i];
109			}
110			}
111			}
112			if (chunkId == 'LIST') {
113			return chunk.length ? chunk : null;
114			}
115			return null;
116			}
117
118			/**
119			* Read the main chunk of a RIFF file.
120			* @param {!Uint8Array} bytes A RIFF file buffer.
121			* @throws {Error} If container is not RIFF, RIFX or RF64.
122			* @protected
123			*/
124			readRIFFChunk(bytes) {
125			this.head_ = 0;
126			this.container = this.readString(bytes, 4);
127			if (['RIFF', 'RIFX', 'RF64'].indexOf(this.container) === -1) {
128			throw Error('Not a supported format.');
129			}
130			this.uInt16_.be = this.container === 'RIFX';
131			this.uInt32_.be = this.uInt16_.be;
132			this.chunkSize = this.readNumber(bytes, this.uInt32_);
133			this.format = this.readString(bytes, 4);
134			}
135
136			/**
137			* Read bytes as a string from a RIFF chunk.
138			* @param {!Uint8Array} bytes The bytes.
139			* @param {number} maxSize the max size of the string.
140			* @return {string} The string.
141			* @protected
142			*/
143			readString(bytes, maxSize) {
144			/** @type {string} */
145			let str = '';
146			str = unpackString(bytes, this.head_, this.head_ + maxSize);
147			this.head_ += maxSize;
148			return str;
149			}
150
151			/**
152			* Read a number from a chunk.
153			* @param {!Uint8Array} bytes The chunk bytes.
154			* @param {!Object} bdType The type definition.
155			* @return {number} The number.
156			* @protected
157			*/
158			readNumber(bytes, bdType) {
159			/** @type {number} */
160			let size = bdType.bits / 8;
161			/** @type {number} */
162			let value = unpack(bytes, bdType, this.head_);
163			this.head_ += size;
164			return value;
165			}
166
167			/**
168			* Return the sub chunks of a RIFF file.
169			* @param {!Uint8Array} buffer the RIFF file bytes.
170			* @return {!Array<Object>} The subchunks of a RIFF/RIFX or LIST chunk.
171			* @private
172			*/
173			getSubChunksIndex_(buffer) {
174			/** @type {!Array<!Object>} */
175			let chunks = [];
176			/** @type {number} */
177			let i = this.head_;
178			while(i <= buffer.length - 8) {
179			chunks.push(this.getSubChunkIndex_(buffer, i));
180			i += 8 + chunks[chunks.length - 1].chunkSize;
181			i = i % 2 ? i + 1 : i;
182			}
183			return chunks;
184			}
185
186			/**
187			* Return a sub chunk from a RIFF file.
188			* @param {!Uint8Array} buffer the RIFF file bytes.
189			* @param {number} index The start index of the chunk.
190			* @return {!Object} A subchunk of a RIFF/RIFX or LIST chunk.
191			* @private
192			*/
193			getSubChunkIndex_(buffer, index) {
194			/** @type {!Object} */
195			let chunk = {
196			chunkId: this.getChunkId_(buffer, index),
197			chunkSize: this.getChunkSize_(buffer, index),
198			};
199			if (chunk.chunkId == 'LIST') {
200			chunk.format = unpackString(buffer, index + 8, index + 12);
201			this.head_ += 4;
202			chunk.subChunks = this.getSubChunksIndex_(buffer);
203			} else {
204			/** @type {number} */
205			let realChunkSize = chunk.chunkSize % 2 ?
206			chunk.chunkSize + 1 : chunk.chunkSize;
207			this.head_ = index + 8 + realChunkSize;
208			chunk.chunkData = {
209			start: index + 8,
210			end: this.head_
211			};
212			}
213			return chunk;
214			}
215
216			/**
217			* Return the fourCC_ of a chunk.
218			* @param {!Uint8Array} buffer the RIFF file bytes.
219			* @param {number} index The start index of the chunk.
220			* @return {string} The id of the chunk.
221			* @private
222			*/
223			getChunkId_(buffer, index) {
224			this.head_ += 4;
225			return unpackString(buffer, index, index + 4);
226			}
227
228			/**
229			* Return the size of a chunk.
230			* @param {!Uint8Array} buffer the RIFF file bytes.
231			* @param {number} index The start index of the chunk.
232			* @return {number} The size of the chunk without the id and size fields.
233			* @private
234			*/
235			getChunkSize_(buffer, index) {
236			this.head_ += 4;
237			return unpack(buffer, this.uInt32_, index + 4);
238			}
239			}
240

rochars / wavefile

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RIFFFile.getSubChunkIndex_ A

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