web-audio-api/build/AudioBufferSourceNode.js

Node.js implementation of Web audio API

var constants = require('./constants')
  , AudioNode = require('./AudioNode')
  , AudioParam = require('./AudioParam')
  , AudioBuffer = require('./AudioBuffer')
  , readOnlyAttr = require('./utils').readOnlyAttr


var AudioBufferSourceNode = (function(super$0){"use strict";var PRS$0 = (function(o,t){o["__proto__"]={"a":t};return o["a"]===t})({},{});var DP$0 = Object.defineProperty;var GOPD$0 = Object.getOwnPropertyDescriptor;var MIXIN$0 = function(t,s){for(var p in s){if(s.hasOwnProperty(p)){DP$0(t,p,GOPD$0(s,p));}}return t};var SP$0 = Object.setPrototypeOf||function(o,p){if(PRS$0){o["__proto__"]=p;}else {DP$0(o,"__proto__",{"value":p,"configurable":true,"enumerable":false,"writable":true});}return o};var OC$0 = Object.create;if(!PRS$0)MIXIN$0(AudioBufferSourceNode, super$0);var proto$0={};

  function AudioBufferSourceNode(context) {
    super$0.call(this, context, 0, 1, undefined, 'max', 'speakers')

    this.buffer = null
    this.loop = false
    this.loopStart = 0
    this.loopEnd = 0

    readOnlyAttr(this, 'playbackRate', new AudioParam(this.context, 1, 'a'))

    this._dsp = this._dspZeros
  }if(super$0!==null)SP$0(AudioBufferSourceNode,super$0);AudioBufferSourceNode.prototype = OC$0(super$0!==null?super$0.prototype:null,{"constructor":{"value":AudioBufferSourceNode,"configurable":true,"writable":true}});DP$0(AudioBufferSourceNode,"prototype",{"configurable":false,"enumerable":false,"writable":false});

  proto$0.start = function(when, offset, duration) {var this$0 = this;
    this._schedule('start', when, function()  {
      if (!this$0.buffer) throw new Error('invalid buffer')

      // Subsequent calls to `start` have no effect
      this$0.start = function() {}

      // keeps track of the current position in the buffer
      var blockSize = constants.BLOCK_SIZE,
        sampleRate = this$0.context.sampleRate,
        cursor, cursorEnd, cursorNext, missingFrames, outBuffer

      var reinitPlayback = function()  {
        cursor = (offset ? offset : this$0.loopStart) * sampleRate
        if (duration) cursorEnd = cursor + duration * sampleRate
        else if (this$0.loopEnd) cursorEnd = this$0.loopEnd * sampleRate
        else cursorEnd = this$0.buffer.length
        cursorNext = cursor
      }
      reinitPlayback()

      this$0._dsp = function() {
        cursorNext = cursor + blockSize
        // If there's enough data left to be read in the buffer, just read it,
        // otherwise we need to handle things a bit differently
        if (cursorNext < cursorEnd) {
          outBuffer = this.buffer.slice(cursor, cursorNext)
          cursor = cursorNext
          return outBuffer
        } else {
          outBuffer = new AudioBuffer(this.buffer.numberOfChannels, blockSize, sampleRate)
          outBuffer.set(this.buffer.slice(cursor, cursorNext))
          // If looping, we must reinitialize our cursor variables.
          // If not looping, we free the node
          if (this.loop) {
            missingFrames = cursorNext - cursorEnd
            reinitPlayback()
            cursorNext = cursor + missingFrames
            outBuffer.set(this.buffer.slice(cursor, cursorNext), outBuffer.length - missingFrames)
          } else {
            if (this.onended) {
              this._schedule('onended', this.context.currentTime + (cursorNext - cursorEnd) / sampleRate, this.onended)
            }
            this._schedule('kill', this.context.currentTime + (cursorNext - cursorEnd) / sampleRate, this._kill.bind(this))
          }
          cursor = cursorNext
          return outBuffer
        }
      }

    })
  };

  proto$0.stop = function(when) {var this$0 = this;
    this._schedule('stop', when, function()  {
      this$0._dsp = this$0._dspZeros
    })
  };

  proto$0.onended = function() {};

  proto$0._tick = function() {
    super$0.prototype._tick.call(this, arguments)
    return this._dsp()
  };

  proto$0._dsp = function() {};

  proto$0._dspZeros = function() {
    return new AudioBuffer(1, constants.BLOCK_SIZE, this.context.sampleRate)
  };

MIXIN$0(AudioBufferSourceNode.prototype,proto$0);proto$0=void 0;return AudioBufferSourceNode;})(AudioNode);

module.exports = AudioBufferSourceNode