Tone.js/Tone/core/Buffer.js

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JavaScript

define(["Tone/core/Tone", "Tone/core/Emitter", "Tone/type/Type"], function(Tone){
"use strict";
/**
* AudioBuffer.copyToChannel polyfill
* @private
*/
if (window.AudioBuffer && !AudioBuffer.prototype.copyToChannel){
AudioBuffer.prototype.copyToChannel = function(src, chanNum, start){
var channel = this.getChannelData(chanNum);
start = start || 0;
for (var i = 0; i < channel.length; i++){
channel[i+start] = src[i];
}
};
AudioBuffer.prototype.copyFromChannel = function(dest, chanNum, start){
var channel = this.getChannelData(chanNum);
start = start || 0;
for (var i = 0; i < dest.length; i++){
dest[i] = channel[i+start];
}
};
}
/**
* @class Buffer loading and storage. Tone.Buffer is used internally by all
* classes that make requests for audio files such as Tone.Player,
* Tone.Sampler and Tone.Convolver.
*
* Aside from load callbacks from individual buffers, Tone.Buffer
* provides events which keep track of the loading progress
* of _all_ of the buffers. These are Tone.Buffer.on("load" / "progress" / "error")
*
* @constructor
* @extends {Tone}
* @param {AudioBuffer|String} url The url to load, or the audio buffer to set.
* @param {Function=} onload A callback which is invoked after the buffer is loaded.
* It's recommended to use `Tone.Buffer.on('load', callback)` instead
* since it will give you a callback when _all_ buffers are loaded.
* @param {Function=} onerror The callback to invoke if there is an error
* @example
* var buffer = new Tone.Buffer("path/to/sound.mp3", function(){
* //the buffer is now available.
* var buff = buffer.get();
* });
* @example
* //can load provide fallback extension types if the first type is not supported.
* var buffer = new Tone.Buffer("path/to/sound.[mp3|ogg|wav]");
*/
Tone.Buffer = function(){
var options = Tone.defaults(arguments, ["url", "onload", "onerror"], Tone.Buffer);
Tone.call(this);
/**
* stores the loaded AudioBuffer
* @type {AudioBuffer}
* @private
*/
this._buffer = null;
/**
* indicates if the buffer should be reversed or not
* @type {Boolean}
* @private
*/
this._reversed = options.reverse;
/**
* The XHR
* @type {XMLHttpRequest}
* @private
*/
this._xhr = null;
if (options.url instanceof AudioBuffer || options.url instanceof Tone.Buffer){
this.set(options.url);
// invoke the onload callback
if (options.onload){
options.onload(this);
}
} else if (Tone.isString(options.url)){
this.load(options.url, options.onload, options.onerror);
}
};
Tone.extend(Tone.Buffer);
/**
* the default parameters
* @type {Object}
*/
Tone.Buffer.defaults = {
"url" : undefined,
"reverse" : false
};
/**
* Pass in an AudioBuffer or Tone.Buffer to set the value
* of this buffer.
* @param {AudioBuffer|Tone.Buffer} buffer the buffer
* @returns {Tone.Buffer} this
*/
Tone.Buffer.prototype.set = function(buffer){
if (buffer instanceof Tone.Buffer){
this._buffer = buffer.get();
} else {
this._buffer = buffer;
}
return this;
};
/**
* @return {AudioBuffer} The audio buffer stored in the object.
*/
Tone.Buffer.prototype.get = function(){
return this._buffer;
};
/**
* Makes an xhr reqest for the selected url then decodes
* the file as an audio buffer. Invokes
* the callback once the audio buffer loads.
* @param {String} url The url of the buffer to load.
* filetype support depends on the
* browser.
* @returns {Promise} returns a Promise which resolves with the Tone.Buffer
*/
Tone.Buffer.prototype.load = function(url, onload, onerror){
var promise = new Promise(function(load, error){
this._xhr = Tone.Buffer.load(url,
//success
function(buff){
this._xhr = null;
this.set(buff);
load(this);
if (onload){
onload(this);
}
}.bind(this),
//error
function(err){
this._xhr = null;
error(err);
if (onerror){
onerror(err);
}
}.bind(this));
}.bind(this));
return promise;
};
/**
* dispose and disconnect
* @returns {Tone.Buffer} this
*/
Tone.Buffer.prototype.dispose = function(){
Tone.prototype.dispose.call(this);
this._buffer = null;
if (this._xhr){
Tone.Buffer._removeFromDownloadQueue(this._xhr);
this._xhr.abort();
this._xhr = null;
}
return this;
};
/**
* If the buffer is loaded or not
* @memberOf Tone.Buffer#
* @type {Boolean}
* @name loaded
* @readOnly
*/
Object.defineProperty(Tone.Buffer.prototype, "loaded", {
get : function(){
return this.length > 0;
},
});
/**
* The duration of the buffer.
* @memberOf Tone.Buffer#
* @type {Number}
* @name duration
* @readOnly
*/
Object.defineProperty(Tone.Buffer.prototype, "duration", {
get : function(){
if (this._buffer){
return this._buffer.duration;
} else {
return 0;
}
},
});
/**
* The length of the buffer in samples
* @memberOf Tone.Buffer#
* @type {Number}
* @name length
* @readOnly
*/
Object.defineProperty(Tone.Buffer.prototype, "length", {
get : function(){
if (this._buffer){
return this._buffer.length;
} else {
return 0;
}
},
});
/**
* The number of discrete audio channels. Returns 0 if no buffer
* is loaded.
* @memberOf Tone.Buffer#
* @type {Number}
* @name numberOfChannels
* @readOnly
*/
Object.defineProperty(Tone.Buffer.prototype, "numberOfChannels", {
get : function(){
if (this._buffer){
return this._buffer.numberOfChannels;
} else {
return 0;
}
},
});
/**
* Set the audio buffer from the array. To create a multichannel AudioBuffer,
* pass in a multidimensional array.
* @param {Float32Array} array The array to fill the audio buffer
* @return {Tone.Buffer} this
*/
Tone.Buffer.prototype.fromArray = function(array){
var isMultidimensional = array[0].length > 0;
var channels = isMultidimensional ? array.length : 1;
var len = isMultidimensional ? array[0].length : array.length;
var buffer = this.context.createBuffer(channels, len, this.context.sampleRate);
if (!isMultidimensional && channels === 1){
array = [array];
}
for (var c = 0; c < channels; c++){
buffer.copyToChannel(array[c], c);
}
this._buffer = buffer;
return this;
};
/**
* Sums muliple channels into 1 channel
* @param {Number=} channel Optionally only copy a single channel from the array.
* @return {Array}
*/
Tone.Buffer.prototype.toMono = function(chanNum){
if (Tone.isNumber(chanNum)){
this.fromArray(this.toArray(chanNum));
} else {
var outputArray = new Float32Array(this.length);
var numChannels = this.numberOfChannels;
for (var channel = 0; channel < numChannels; channel++){
var channelArray = this.toArray(channel);
for (var i = 0; i < channelArray.length; i++){
outputArray[i] += channelArray[i];
}
}
//divide by the number of channels
outputArray = outputArray.map(function(sample){
return sample / numChannels;
});
this.fromArray(outputArray);
}
return this;
};
/**
* Get the buffer as an array. Single channel buffers will return a 1-dimensional
* Float32Array, and multichannel buffers will return multidimensional arrays.
* @param {Number=} channel Optionally only copy a single channel from the array.
* @return {Array}
*/
Tone.Buffer.prototype.toArray = function(channel){
if (Tone.isNumber(channel)){
return this.getChannelData(channel);
} else if (this.numberOfChannels === 1){
return this.toArray(0);
} else {
var ret = [];
for (var c = 0; c < this.numberOfChannels; c++){
ret[c] = this.getChannelData(c);
}
return ret;
}
};
/**
* Returns the Float32Array representing the PCM audio data for the specific channel.
* @param {Number} channel The channel number to return
* @return {Float32Array} The audio as a TypedArray
*/
Tone.Buffer.prototype.getChannelData = function(channel){
return this._buffer.getChannelData(channel);
};
/**
* Cut a subsection of the array and return a buffer of the
* subsection. Does not modify the original buffer
* @param {Time} start The time to start the slice
* @param {Time=} end The end time to slice. If none is given
* will default to the end of the buffer
* @return {Tone.Buffer} this
*/
Tone.Buffer.prototype.slice = function(start, end){
end = Tone.defaultArg(end, this.duration);
var startSamples = Math.floor(this.context.sampleRate * this.toSeconds(start));
var endSamples = Math.floor(this.context.sampleRate * this.toSeconds(end));
var replacement = [];
for (var i = 0; i < this.numberOfChannels; i++){
replacement[i] = this.toArray(i).slice(startSamples, endSamples);
}
var retBuffer = new Tone.Buffer().fromArray(replacement);
return retBuffer;
};
/**
* Reverse the buffer.
* @private
* @return {Tone.Buffer} this
*/
Tone.Buffer.prototype._reverse = function(){
if (this.loaded){
for (var i = 0; i < this.numberOfChannels; i++){
Array.prototype.reverse.call(this.getChannelData(i));
}
}
return this;
};
/**
* Reverse the buffer.
* @memberOf Tone.Buffer#
* @type {Boolean}
* @name reverse
*/
Object.defineProperty(Tone.Buffer.prototype, "reverse", {
get : function(){
return this._reversed;
},
set : function(rev){
if (this._reversed !== rev){
this._reversed = rev;
this._reverse();
}
},
});
///////////////////////////////////////////////////////////////////////////
// STATIC METHODS
///////////////////////////////////////////////////////////////////////////
//statically inherits Emitter methods
Tone.Emitter.mixin(Tone.Buffer);
/**
* the static queue for all of the xhr requests
* @type {Array}
* @private
*/
Tone.Buffer._downloadQueue = [];
/**
* A path which is prefixed before every url.
* @type {String}
* @static
*/
Tone.Buffer.baseUrl = "";
/**
* Create a Tone.Buffer from the array. To create a multichannel AudioBuffer,
* pass in a multidimensional array.
* @param {Float32Array} array The array to fill the audio buffer
* @return {Tone.Buffer} A Tone.Buffer created from the array
*/
Tone.Buffer.fromArray = function(array){
return (new Tone.Buffer()).fromArray(array);
};
/**
* Remove an xhr request from the download queue
* @private
*/
Tone.Buffer._removeFromDownloadQueue = function(request){
var index = Tone.Buffer._downloadQueue.indexOf(request);
if (index !== -1){
Tone.Buffer._downloadQueue.splice(index, 1);
}
};
/**
* Loads a url using XMLHttpRequest.
* @param {String} url
* @param {Function} onload
* @param {Function} onerror
* @param {Function} onprogress
* @return {XMLHttpRequest}
*/
Tone.Buffer.load = function(url, onload, onerror){
//default
onload = Tone.defaultArg(onload, Tone.noOp);
// test if the url contains multiple extensions
var matches = url.match(/\[(.+\|?)+\]$/);
if (matches){
var extensions = matches[1].split("|");
var extension = extensions[0];
for (var i = 0; i < extensions.length; i++){
if (Tone.Buffer.supportsType(extensions[i])){
extension = extensions[i];
break;
}
}
url = url.replace(matches[0], extension);
}
function onError(e){
Tone.Buffer._removeFromDownloadQueue(request);
Tone.Buffer.emit("error", e);
if (onerror){
onerror(e);
} else {
throw e;
}
}
function onProgress(){
//calculate the progress
var totalProgress = 0;
for (var i = 0; i < Tone.Buffer._downloadQueue.length; i++){
totalProgress += Tone.Buffer._downloadQueue[i].progress;
}
Tone.Buffer.emit("progress", totalProgress / Tone.Buffer._downloadQueue.length);
}
var request = new XMLHttpRequest();
request.open("GET", Tone.Buffer.baseUrl + url, true);
request.responseType = "arraybuffer";
//start out as 0
request.progress = 0;
Tone.Buffer._downloadQueue.push(request);
request.addEventListener("load", function(){
if (request.status === 200){
Tone.context.decodeAudioData(request.response, function(buff) {
request.progress = 1;
onProgress();
onload(buff);
Tone.Buffer._removeFromDownloadQueue(request);
if (Tone.Buffer._downloadQueue.length === 0){
//emit the event at the end
Tone.Buffer.emit("load");
}
}, function(){
Tone.Buffer._removeFromDownloadQueue(request);
onError("Tone.Buffer: could not decode audio data: "+url);
});
} else {
onError("Tone.Buffer: could not locate file: "+url);
}
});
request.addEventListener("error", onError);
request.addEventListener("progress", function(event){
if (event.lengthComputable){
//only go to 95%, the last 5% is when the audio is decoded
request.progress = (event.loaded / event.total) * 0.95;
onProgress();
}
});
request.send();
return request;
};
/**
* Stop all of the downloads in progress
* @return {Tone.Buffer}
* @static
*/
Tone.Buffer.cancelDownloads = function(){
Tone.Buffer._downloadQueue.slice().forEach(function(request){
Tone.Buffer._removeFromDownloadQueue(request);
request.abort();
});
return Tone.Buffer;
};
/**
* Checks a url's extension to see if the current browser can play that file type.
* @param {String} url The url/extension to test
* @return {Boolean} If the file extension can be played
* @static
* @example
* Tone.Buffer.supportsType("wav"); //returns true
* Tone.Buffer.supportsType("path/to/file.wav"); //returns true
*/
Tone.Buffer.supportsType = function(url){
var extension = url.split(".");
extension = extension[extension.length - 1];
var response = document.createElement("audio").canPlayType("audio/"+extension);
return response !== "";
};
/**
* Returns a Promise which resolves when all of the buffers have loaded
* @return {Promise}
*/
Tone.loaded = function(){
var onload, onerror;
function removeEvents(){
//remove the events when it's resolved
Tone.Buffer.off("load", onload);
Tone.Buffer.off("error", onerror);
}
return new Promise(function(success, fail){
onload = function(){
success();
};
onerror = function(){
fail();
};
//add the event listeners
Tone.Buffer.on("load", onload);
Tone.Buffer.on("error", onerror);
}).then(removeEvents).catch(function(e){
removeEvents();
throw new Error(e);
});
};
return Tone.Buffer;
});