rochars / wavefile

 * 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 WaveFileMetaEditor class.

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

 */

import { WaveFileCreator } from './wavefile-creator';

/**

 * A class to edit meta information in wav files.

 * @extends WaveFileCreator

 * @ignore

 */

export class WaveFileMetaEditor extends WaveFileCreator {

  /**

   * Return the value of a RIFF tag in the INFO chunk.

   * @param {string} tag The tag name.

   * @return {?string} The value if the tag is found, null otherwise.

   */

  getTag(tag) {

    /** @type {!Object} */

    let index = this.getTagIndex_(tag);

    if (index.TAG !== null) {

      return this.LIST[index.LIST].subChunks[index.TAG].value;

    }

    return null;

  }

  /**

   * Write a RIFF tag in the INFO chunk. If the tag do not exist,

   * then it is created. It if exists, it is overwritten.

   * @param {string} tag The tag name.

   * @param {string} value The tag value.

   * @throws {Error} If the tag name is not valid.

   */

  setTag(tag, value) {

    tag = fixRIFFTag_(tag);

    /** @type {!Object} */

    let index = this.getTagIndex_(tag);

    if (index.TAG !== null) {

      this.LIST[index.LIST].subChunks[index.TAG].chunkSize =

        value.length + 1;

      this.LIST[index.LIST].subChunks[index.TAG].value = value;

    } else if (index.LIST !== null) {

      this.LIST[index.LIST].subChunks.push({

        chunkId: tag,

        chunkSize: value.length + 1,

        value: value});

    } else {

      this.LIST.push({

        chunkId: 'LIST',

        chunkSize: 8 + value.length + 1,

        format: 'INFO',

        subChunks: []});

      this.LIST[this.LIST.length - 1].subChunks.push({

        chunkId: tag,

        chunkSize: value.length + 1,

        value: value});

    }

  }

  /**

   * Remove a RIFF tag from the INFO chunk.

   * @param {string} tag The tag name.

   * @return {boolean} True if a tag was deleted.

   */

  deleteTag(tag) {

    /** @type {!Object} */

    let index = this.getTagIndex_(tag);

    if (index.TAG !== null) {

      this.LIST[index.LIST].subChunks.splice(index.TAG, 1);

      return true;

    }

    return false;

  }

  /**

   * Return a Object<tag, value> with the RIFF tags in the file.

   * @return {!Object<string, string>} The file tags.

   */

  listTags() {

    /** @type {?number} */

    let index = this.getLISTINFOIndex_();

    /** @type {!Object} */

    let tags = {};

    if (index !== null) {

      for (let i = 0, len = this.LIST[index].subChunks.length; i < len; i++) {

        tags[this.LIST[index].subChunks[i].chunkId] =

          this.LIST[index].subChunks[i].value;

      }

    }

    return tags;

  }

  /**

   * Return an array with all cue points in the file, in the order they appear

   * in the file.

   * Objects representing cue points/regions look like this:

   *   {

   *     position: 500, // the position in milliseconds

   *     label: 'cue marker 1',

   *     end: 1500, // the end position in milliseconds

   *     dwName: 1,

   *     dwPosition: 0,

   *     fccChunk: 'data',

   *     dwChunkStart: 0,

   *     dwBlockStart: 0,

   *     dwSampleOffset: 22050, // the position as a sample offset

   *     dwSampleLength: 3646827, // length as a sample count, 0 if not a region

   *     dwPurposeID: 544106354,

   *     dwCountry: 0,

   *     dwLanguage: 0,

   *     dwDialect: 0,

   *     dwCodePage: 0,

   *   }

   * @return {!Array<Object>}

   */

  listCuePoints() {

    /** @type {!Array<!Object>} */

    let points = this.getCuePoints_();

    for (let i = 0, len = points.length; i < len; i++) {

      // Add attrs that should exist in the object

      points[i].position =

        (points[i].dwSampleOffset / this.fmt.sampleRate) * 1000;

      // If it is a region, calc the end

      // position in milliseconds

      if (points[i].dwSampleLength) {

        points[i].end =

          (points[i].dwSampleLength / this.fmt.sampleRate) * 1000;

        points[i].end += points[i].position;

      // If its not a region, end should be null

      } else {

        points[i].end = null;

      }

      // Remove attrs that should not go in the results

      delete points[i].value;

    }

    return points;

  }

  /**

   * Create a cue point in the wave file.

   * @param {!{

   *   position: number,

   *   label: ?string,

   *   end: ?number,

   *   dwPurposeID: ?number,

   *   dwCountry: ?number,

   *   dwLanguage: ?number,

   *   dwDialect: ?number,

   *   dwCodePage: ?number

   * }} pointData A object with the data of the cue point.

   *

   * # Only required attribute to create a cue point:

   * pointData.position: The position of the point in milliseconds

   *

   * # Optional attribute for cue points:

   * pointData.label: A string label for the cue point

   *

   * # Extra data used for regions

   * pointData.end: A number representing the end of the region,

   *   in milliseconds, counting from the start of the file. If

   *   no end attr is specified then no region is created.

   *

   * # You may also specify the following attrs for regions, all optional:

   * pointData.dwPurposeID

   * pointData.dwCountry

   * pointData.dwLanguage

   * pointData.dwDialect

   * pointData.dwCodePage

   */

  setCuePoint(pointData) {

    this.cue.chunkId = 'cue ';

    // label attr should always exist

    if (!pointData.label) {

      pointData.label = '';

    }

    /**

     * Load the existing points before erasing

     * the LIST 'adtl' chunk and the cue attr

     * @type {!Array<!Object>}

     */

    let existingPoints = this.getCuePoints_();

    // Clear any LIST labeled 'adtl'

    // The LIST chunk should be re-written

    // after the new cue point is created

    this.clearLISTadtl_();

    // Erase this.cue so it can be re-written

    // after the point is added

    this.cue.points = [];

    /**

     * Cue position param is informed in milliseconds,

     * here its value is converted to the sample offset

     * @type {number}

     */

    pointData.dwSampleOffset =

      (pointData.position * this.fmt.sampleRate) / 1000;

    /**

     * end param is informed in milliseconds, counting

     * from the start of the file.

     * here its value is converted to the sample length

     * of the region.

     * @type {number}

     */

    pointData.dwSampleLength = 0;

    if (pointData.end) {

      pointData.dwSampleLength = 

        ((pointData.end * this.fmt.sampleRate) / 1000) -

        pointData.dwSampleOffset;

    }

    // If there were no cue points in the file,

    // insert the new cue point as the first

    if (existingPoints.length === 0) {

      this.setCuePoint_(pointData, 1);

    // If the file already had cue points, This new one

    // must be added in the list according to its position.

    } else {

      this.setCuePointInOrder_(existingPoints, pointData);

    }

    this.cue.dwCuePoints = this.cue.points.length;

  }

  /**

   * Remove a cue point from a wave file.

   * @param {number} index the index of the point. First is 1,

   *    second is 2, and so on.

   */

  deleteCuePoint(index) {

    this.cue.chunkId = 'cue ';

    /** @type {!Array<!Object>} */

    let existingPoints = this.getCuePoints_();

    this.clearLISTadtl_();

    /** @type {number} */

    let len = this.cue.points.length;

    this.cue.points = [];

    for (let i = 0; i < len; i++) {

      if (i + 1 !== index) {

        this.setCuePoint_(existingPoints[i], i + 1);

      }

    }

    this.cue.dwCuePoints = this.cue.points.length;

    if (this.cue.dwCuePoints) {

      this.cue.chunkId = 'cue ';

    } else {

      this.cue.chunkId = '';

      this.clearLISTadtl_();

    }

  }

  /**

   * Update the label of a cue point.

   * @param {number} pointIndex The ID of the cue point.

   * @param {string} label The new text for the label.

   */

  updateLabel(pointIndex, label) {

    /** @type {?number} */

    let cIndex = this.getAdtlChunk_();

    if (cIndex !== null) {

      for (let i = 0, len = this.LIST[cIndex].subChunks.length; i < len; i++) {

        if (this.LIST[cIndex].subChunks[i].dwName ==

            pointIndex) {

          this.LIST[cIndex].subChunks[i].value = label;

        }

      }

    }

  }

  /**

   * Return an array with all cue points in the file, in the order they appear

   * in the file.

   * @return {!Array<!Object>}

   * @private

   */

  getCuePoints_() {

    /** @type {!Array<!Object>} */

    let points = [];

    for (let i = 0; i < this.cue.points.length; i++) {

      /** @type {!Object} */

      let chunk = this.cue.points[i];

      /** @type {!Object} */

      let pointData = this.getDataForCuePoint_(chunk.dwName);

      pointData.label = pointData.value ? pointData.value : '';

      pointData.dwPosition = chunk.dwPosition;

      pointData.fccChunk = chunk.fccChunk;

      pointData.dwChunkStart = chunk.dwChunkStart;

      pointData.dwBlockStart = chunk.dwBlockStart;

      pointData.dwSampleOffset = chunk.dwSampleOffset;

      points.push(pointData);

    }

    return points;

  }

  /**

   * Return the associated data of a cue point.

   * @param {number} pointDwName The ID of the cue point.

   * @return {!Object}

   * @private

   */

  getDataForCuePoint_(pointDwName) {

    /** @type {?number} */

    let cIndex = this.getAdtlChunk_();

    /** @type {!Object} */

    let pointData = {};

    if (cIndex !== null) {

      // got through all chunks in the adtl LIST checking

      // for references to this cue point

      for (let i = 0, len = this.LIST[cIndex].subChunks.length; i < len; i++) {

        if (this.LIST[cIndex].subChunks[i].dwName ==

            pointDwName && this.LIST[cIndex].subChunks[i].chunkId) {

          /** @type {!Object} */

          let chunk = this.LIST[cIndex].subChunks[i];

          // Some chunks may reference the point but

          // have a empty text; this is to ensure that if

          // one chunk that reference the point has a text,

          // this value will be kept as the associated data label

          // for the cue point.

          // If different values are present, the last value found

          // will be considered the label for the cue point.

          pointData.value = chunk.value ? chunk.value : pointData.value;

          pointData.dwName = chunk.dwName ? chunk.dwName : 0;

          pointData.dwSampleLength =

            chunk.dwSampleLength ? chunk.dwSampleLength : 0;

          pointData.dwPurposeID = chunk.dwPurposeID ? chunk.dwPurposeID : 0;

          pointData.dwCountry = chunk.dwCountry ? chunk.dwCountry : 0;

          pointData.dwLanguage = chunk.dwLanguage ? chunk.dwLanguage : 0;

          pointData.dwDialect = chunk.dwDialect ? chunk.dwDialect : 0;

          pointData.dwCodePage = chunk.dwCodePage ? chunk.dwCodePage : 0;

        }

      }

    }

    return pointData;

  }

  /**

   * Return the index of the INFO chunk in the LIST chunk.

   * @return {?number} the index of the INFO chunk.

   * @private

   */

  getLISTINFOIndex_() {

    /** @type {?number} */

    let index = null;

    for (let i = 0, len = this.LIST.length; i < len; i++) {

      if (this.LIST[i].format === 'INFO') {

        index = i;

        break;

      }

    }

    return index;

  }

  /**

   * Return the index of the 'adtl' LIST in this.LIST.

   * @return {?number}

   * @private

   */

  getAdtlChunk_() {

    for (let i = 0, len = this.LIST.length; i < len; i++) {

      if (this.LIST[i].format == 'adtl') {

        return i;

      }

    }

    return null;

  }

  /**

   * Return the index of a tag in a FILE chunk.

   * @param {string} tag The tag name.

   * @return {!Object<string, ?number>}

   *    Object.LIST is the INFO index in LIST

   *    Object.TAG is the tag index in the INFO

   * @private

   */

  getTagIndex_(tag) {

    /** @type {!Object<string, ?number>} */

    let index = {LIST: null, TAG: null};

    for (let i = 0, len = this.LIST.length; i < len; i++) {

      if (this.LIST[i].format == 'INFO') {

        index.LIST = i;

        for (let j=0, subLen = this.LIST[i].subChunks.length; j < subLen; j++) {

          if (this.LIST[i].subChunks[j].chunkId == tag) {

            index.TAG = j;

            break;

          }

        }

        break;

      }

    }

    return index;

  }

  /**

   * Push a new cue point in this.cue.points.

   * @param {!Object} pointData A object with data of the cue point.

   * @param {number} dwName the dwName of the cue point

   * @private

   */

  setCuePoint_(pointData, dwName) {

    this.cue.points.push({

      dwName: dwName,

      dwPosition: pointData.dwPosition ? pointData.dwPosition : 0,

      fccChunk: pointData.fccChunk ? pointData.fccChunk : 'data',

      dwChunkStart: pointData.dwChunkStart ? pointData.dwChunkStart : 0,

      dwBlockStart: pointData.dwBlockStart ? pointData.dwBlockStart : 0,

      dwSampleOffset: pointData.dwSampleOffset

    });

    this.setLabl_(pointData, dwName);

  }

  /**

   * Push a new cue point in this.cue.points according to existing cue points.

   * @param {!Array} existingPoints Array with the existing points.

   * @param {!Object} pointData A object with data of the cue point.

   * @private

   */

  setCuePointInOrder_(existingPoints, pointData) {

    /** @type {boolean} */

    let hasSet = false;

    // Iterate over the cue points that existed

    // before this one was added

    for (let i = 0; i < existingPoints.length; i++) {

      // If the new point is located before this original point

      // and the new point have not been created, create the

      // new point and then the original point

      if (existingPoints[i].dwSampleOffset > 

        pointData.dwSampleOffset && !hasSet) {

        // create the new point

        this.setCuePoint_(pointData, i + 1);

        // create the original point

        this.setCuePoint_(existingPoints[i], i + 2);

        hasSet = true;

      // Otherwise, re-create the original point

      } else {

        this.setCuePoint_(existingPoints[i], hasSet ? i + 2 : i + 1);

      }

    }

    // If no point was created in the above loop,

    // create the new point as the last one

    if (!hasSet) {

      this.setCuePoint_(pointData, this.cue.points.length + 1);

    }

  }

  /**

   * Clear any LIST chunk labeled as 'adtl'.

   * @private

   */

  clearLISTadtl_() {

    for (let i = 0, len = this.LIST.length; i < len; i++) {

      if (this.LIST[i].format == 'adtl') {

        this.LIST.splice(i);

      }

    }

  }

  /**

   * Create a new 'labl' subchunk in a 'LIST' chunk of type 'adtl'.

   * This method creates a LIST adtl chunk in the file if one

   * is not present.

   * @param {!Object} pointData A object with data of the cue point.

   * @param {number} dwName The ID of the cue point.

   * @private

   */

  setLabl_(pointData, dwName) {

    /**

     * Get the index of the LIST chunk labeled as adtl.

     * A file can have many LIST chunks with unique labels.

     * @type {?number}

     */

    let adtlIndex = this.getAdtlChunk_();

    // If there is no adtl LIST, create one

    if (adtlIndex === null) {

      // Include a new item LIST chunk

      this.LIST.push({

        chunkId: 'LIST',

        chunkSize: 4,

        format: 'adtl',

        subChunks: []});

      // Get the index of the new LIST chunk

      adtlIndex = this.LIST.length - 1;

    }

    this.setLabelText_(adtlIndex, pointData, dwName);

    if (pointData.dwSampleLength) {

      this.setLtxtChunk_(adtlIndex, pointData, dwName);

    }

  }

  /**

   * Create a new 'labl' subchunk in a 'LIST' chunk of type 'adtl'.

   * @param {number} adtlIndex The index of the 'adtl' LIST in this.LIST.

   * @param {!Object} pointData A object with data of the cue point.

   * @param {number} dwName The ID of the cue point.

   * @private

   */

   * Create a new 'ltxt' subchunk in a 'LIST' chunk of type 'adtl'.

   * @param {number} adtlIndex The index of the 'adtl' LIST in this.LIST.

   * @param {!Object} pointData A object with data of the cue point.

   * @param {number} dwName The ID of the cue point.

   * @private

   */

  setLtxtChunk_(adtlIndex, pointData, dwName) {

    this.LIST[adtlIndex].subChunks.push({

      chunkId: 'ltxt',

      chunkSize: 20,  // should be 12 + label byte length

      dwName: dwName,

      dwSampleLength: pointData.dwSampleLength,

      dwPurposeID: pointData.dwPurposeID ? pointData.dwPurposeID : 0,

      dwCountry: pointData.dwCountry ? pointData.dwCountry : 0,

      dwLanguage: pointData.dwLanguage ? pointData.dwLanguage : 0,

      dwDialect: pointData.dwDialect ? pointData.dwDialect : 0,

      dwCodePage: pointData.dwCodePage ? pointData.dwCodePage : 0,

      value: pointData.label // kept for compatibility

    });

    this.LIST[adtlIndex].chunkSize += 28;

  }

}

/**

 * Fix a RIFF tag format if possible, throw an error otherwise.

 * @param {string} tag The tag name.

 * @return {string} The tag name in proper fourCC format.

 * @private

 */

function fixRIFFTag_(tag) {

  if (tag.constructor !== String) {

    throw new Error('Invalid tag name.');

  } else if (tag.length < 4) {

    for (let i = 0, len = 4 - tag.length; i < len; i++) {

      tag += ' ';

    }

  }

  return tag;

}