mp4box/src/DataStream-map.js

JavaScript version of GPAC's MP4Box tool

/**
  Maps an Int32Array into the DataStream buffer, swizzling it to native
  endianness in-place. The current offset from the start of the buffer needs to
  be a multiple of element size, just like with typed array views.

  Nice for quickly reading in data. Warning: potentially modifies the buffer
  contents.

  @param {number} length Number of elements to map.
  @param {?boolean} e Endianness of the data to read.
  @return {Object} Int32Array to the DataStream backing buffer.
  */
DataStream.prototype.mapInt32Array = function(length, e) {
  this._realloc(length * 4);
  var arr = new Int32Array(this._buffer, this.byteOffset+this.position, length);
  DataStream.arrayToNative(arr, e == null ? this.endianness : e);
  this.position += length * 4;
  return arr;
};

/**
  Maps an Int16Array into the DataStream buffer, swizzling it to native
  endianness in-place. The current offset from the start of the buffer needs to
  be a multiple of element size, just like with typed array views.

  Nice for quickly reading in data. Warning: potentially modifies the buffer
  contents.

  @param {number} length Number of elements to map.
  @param {?boolean} e Endianness of the data to read.
  @return {Object} Int16Array to the DataStream backing buffer.
  */
DataStream.prototype.mapInt16Array = function(length, e) {
  this._realloc(length * 2);
  var arr = new Int16Array(this._buffer, this.byteOffset+this.position, length);
  DataStream.arrayToNative(arr, e == null ? this.endianness : e);
  this.position += length * 2;
  return arr;
};

/**
  Maps an Int8Array into the DataStream buffer.

  Nice for quickly reading in data.

  @param {number} length Number of elements to map.
  @param {?boolean} e Endianness of the data to read.
  @return {Object} Int8Array to the DataStream backing buffer.
  */
DataStream.prototype.mapInt8Array = function(length) {
  this._realloc(length * 1);
  var arr = new Int8Array(this._buffer, this.byteOffset+this.position, length);
  this.position += length * 1;
  return arr;
};

/**
  Maps a Uint32Array into the DataStream buffer, swizzling it to native
  endianness in-place. The current offset from the start of the buffer needs to
  be a multiple of element size, just like with typed array views.

  Nice for quickly reading in data. Warning: potentially modifies the buffer
  contents.

  @param {number} length Number of elements to map.
  @param {?boolean} e Endianness of the data to read.
  @return {Object} Uint32Array to the DataStream backing buffer.
  */
DataStream.prototype.mapUint32Array = function(length, e) {
  this._realloc(length * 4);
  var arr = new Uint32Array(this._buffer, this.byteOffset+this.position, length);
  DataStream.arrayToNative(arr, e == null ? this.endianness : e);
  this.position += length * 4;
  return arr;
};

/**
  Maps a Uint16Array into the DataStream buffer, swizzling it to native
  endianness in-place. The current offset from the start of the buffer needs to
  be a multiple of element size, just like with typed array views.

  Nice for quickly reading in data. Warning: potentially modifies the buffer
  contents.

  @param {number} length Number of elements to map.
  @param {?boolean} e Endianness of the data to read.
  @return {Object} Uint16Array to the DataStream backing buffer.
  */
DataStream.prototype.mapUint16Array = function(length, e) {
  this._realloc(length * 2);
  var arr = new Uint16Array(this._buffer, this.byteOffset+this.position, length);
  DataStream.arrayToNative(arr, e == null ? this.endianness : e);
  this.position += length * 2;
  return arr;
};

/**
  Maps a Float64Array into the DataStream buffer, swizzling it to native
  endianness in-place. The current offset from the start of the buffer needs to
  be a multiple of element size, just like with typed array views.

  Nice for quickly reading in data. Warning: potentially modifies the buffer
  contents.

  @param {number} length Number of elements to map.
  @param {?boolean} e Endianness of the data to read.
  @return {Object} Float64Array to the DataStream backing buffer.
  */
DataStream.prototype.mapFloat64Array = function(length, e) {
  this._realloc(length * 8);
  var arr = new Float64Array(this._buffer, this.byteOffset+this.position, length);
  DataStream.arrayToNative(arr, e == null ? this.endianness : e);
  this.position += length * 8;
  return arr;
};

/**
  Maps a Float32Array into the DataStream buffer, swizzling it to native
  endianness in-place. The current offset from the start of the buffer needs to
  be a multiple of element size, just like with typed array views.

  Nice for quickly reading in data. Warning: potentially modifies the buffer
  contents.

  @param {number} length Number of elements to map.
  @param {?boolean} e Endianness of the data to read.
  @return {Object} Float32Array to the DataStream backing buffer.
  */
DataStream.prototype.mapFloat32Array = function(length, e) {
  this._realloc(length * 4);
  var arr = new Float32Array(this._buffer, this.byteOffset+this.position, length);
  DataStream.arrayToNative(arr, e == null ? this.endianness : e);
  this.position += length * 4;
  return arr;
};