├── README.md
└── buffaudio.js


/README.md:
--------------------------------------------------------------------------------
 1 | #BuffAudio.js
 2 | 
 3 | BuffAudio.js is a wrapper around some of the HTML5 Web Audio API that lets you work easily with an AudioBuffer. The primary goals are to enable play, pause, stop, seek, and volume control.
 4 | 
 5 | Here are some helpful docs from Mozilla on the Web Audio API:
 6 | 
 7 | * [AudioBuffer](https://developer.mozilla.org/en-US/docs/Web/API/AudioBuffer)
 8 | * [AudioContext](https://developer.mozilla.org/en-US/docs/Web/API/AudioContext)
 9 | * [AudioBufferSourceNode](https://developer.mozilla.org/en-US/docs/Web/API/AudioBufferSourceNode)
10 | * [AudioNode](https://developer.mozilla.org/en-US/docs/Web/API/AudioNode)
11 | 
12 | ##Usage:
13 | 
14 |     // audioContext is an AudioContext object: https://developer.mozilla.org/en-US/docs/Web/API/AudioContext
15 |     // buffer is an AudioBuffer object: https://developer.mozilla.org/en-US/docs/Web/API/AudioBuffer
16 |     var buffAudio = new BuffAudio(audioContext, buffer);
17 |     buffAudio.play();
18 |     buffAudio.pause();
19 |     buffAudio.play();
20 |     buffAudio.seek(5); // seconds
21 |     buffAudio.stop();
22 |     
23 |     buffAudio.initNewBuffer(buffer2);
24 |     buffAudio.play();
25 | 
26 | ##Documentation:
27 | __initNewBuffer(buffer)__  
28 | Sets a new `buffer` (AudioBuffer). Will replace any existing AudioBuffer.
29 | 
30 | __play()__  
31 | Plays the current buffer. If playback was paused (`pause()`) previously, it will resume where it left off. If playback was stopped (`stop()`) or played the entire AudioBuffer, playback will start from the beginning.
32 | 
33 | __pause()__  
34 | Pauses playback and keeps track of time.
35 | 
36 | __seek(time)__  
37 | Moves the current playback time to the `time` (in seconds) passed in. `seek` does not alter the current playback state, i.e. if the buffer is playing, it will continue playing from the new point, and if it is not playing it will not start playing.
38 | 
39 | __stop()__  
40 | Stops playback. Playback time is set to the beginning of the buffer.
41 | 
42 | 
43 | __setVolume()__  
44 | UNIMPLEMENTED. Might add some gain nodes or something...
45 | 
46 | 
47 | 
48 | ## Contribute
49 | Please contribute using pull requests. Feel free to email me with questions/critiques/etc. ernie.park@gmail.com
50 | 
51 | ## Issues
52 | Submit issues through GitHub.  
53 | 
54 | __Length issue__ The current version of the spec states: 
55 | 
56 | >This interface represents a memory-resident audio asset (for one-shot sounds and other short audio clips). Its format is non-interleaved IEEE 32-bit linear PCM with a nominal range of -1 -> +1. It can contain one or more channels. Typically, it would be expected that the length of the PCM data would be fairly short (usually somewhat less than a minute). For longer sounds, such as music soundtracks, streaming should be used with the audio element and MediaElementAudioSourceNode.
57 | 
58 | I want to use BuffAudio/AudioBuffers for longer form content that is recorded directly in the browser. It does not seem like MediaElementSourceNode would work very well for this case since I'd have to convert the AudioBuffer I recorded into a format compatible with the <audio> tag first. Is my current method just a hack or is there no real good solution here?
59 |     
60 | 
61 | ## License
62 | The MIT License (MIT)
63 | 
64 | Copyright (c) 2013 Ernest Park (ernie.park@gmail.com)
65 | 
66 | Permission is hereby granted, free of charge, to any person obtaining a copy
67 | of this software and associated documentation files (the "Software"), to deal
68 | in the Software without restriction, including without limitation the rights
69 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
70 | copies of the Software, and to permit persons to whom the Software is
71 | furnished to do so, subject to the following conditions:
72 | 
73 | The above copyright notice and this permission notice shall be included in
74 | all copies or substantial portions of the Software.
75 | 
76 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
77 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
78 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
79 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
80 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
81 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
82 | THE SOFTWARE.
83 | 


--------------------------------------------------------------------------------
/buffaudio.js:
--------------------------------------------------------------------------------
  1 | /**
  2 |  * BuffAudio.js - http://github.com/eipark/buffaudio
  3 |  * A wrapper around the HTML5 Web Audio API to easily play, pause,
  4 |  * and skip around an AudioBuffer.
  5 |  *
  6 |  * https://developer.mozilla.org/en-US/docs/Web/API/AudioBuffer
  7 |  * https://developer.mozilla.org/en-US/docs/Web/API/AudioBufferSourceNode
  8 |  *
  9 |  * The MIT License (MIT)
 10 |  *
 11 |  * Copyright (c) 2013 Ernie Park
 12 |  *
 13 |  * Permission is hereby granted, free of charge, to any person obtaining a copy
 14 |  * of this software and associated documentation files (the "Software"), to deal
 15 |  * in the Software without restriction, including without limitation the rights
 16 |  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 17 |  * copies of the Software, and to permit persons to whom the Software is
 18 |  * furnished to do so, subject to the following conditions:
 19 |  *
 20 |  * The above copyright notice and this permission notice shall be included in
 21 |  * all copies or substantial portions of the Software.
 22 |  *
 23 |  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 24 |  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 25 |  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 26 |  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 27 |  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 28 |  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 29 |  * THE SOFTWARE.
 30 |  */
 31 | (function(window, undefined) {
 32 |   var BuffAudio = function(audioContext, buffer) {
 33 |     this._audioContext = audioContext;
 34 |     this._buffer = buffer; // AudioBuffer
 35 |     this._source; // AudioBufferSourceNode
 36 |     this._playbackTime = 0; // time of the audio playback, seconds
 37 |     this._startTimestamp = 0; // timestamp of last playback start, milliseconds
 38 |     this._isPlaying = false;
 39 |     this._bufferDuration = 0; // seconds
 40 | 
 41 |     // Whenever we get a new AudioBuffer, we create a new AudioBufferSourceNode and reset
 42 |     // the playback time. Make sure any existing audio is stopped beforehand.
 43 |     this.initNewBuffer = function(buffer) {
 44 |       this.stop();
 45 |       this._buffer = buffer;
 46 |       this._playbackTime = 0;
 47 |     }
 48 | 
 49 |     // Create a new AudioBufferSourceNode
 50 |     this.initSource = function() {
 51 |       this._source = this._audioContext.createBufferSource();
 52 |       this._source.buffer = this._buffer;
 53 |       this._source.connect(this._audioContext.destination);
 54 |       // Bind the callback to this
 55 |       var endOfPlayback = this.endOfPlayback.bind(this);
 56 |       this._source.onended = endOfPlayback;
 57 |     }
 58 | 
 59 |     // Play the currently loaded buffer
 60 |     this.play = function() {
 61 |       console.log("Play");
 62 |       if (this._isPlaying) return;
 63 |       var when = 0; // when to schedule playback, 0 is immediately
 64 |       this.initSource();
 65 |       this._source.start(0, this._playbackTime);
 66 |       this._startTimestamp = Date.now();
 67 |       this._isPlaying = true;
 68 |     }
 69 | 
 70 |     // Seek to a specific playbackTime (seconds) in the audio buffer. Do not change
 71 |     // playback state.
 72 |     this.seek = function(playbackTime) {
 73 |       if (playbackTime === undefined) return;
 74 |       if (playbackTime > this._buffer.duration) {
 75 |         console.log("[ERROR] Seek time is greater than duration of audio buffer.");
 76 |         return;
 77 |       }
 78 | 
 79 |       if (this._isPlaying) {
 80 |         this.stop(); // Stop any existing playback if there is any
 81 |         this._playbackTime = playbackTime;
 82 |         this.play(); // Resume playback at new time
 83 |       } else {
 84 |         this._playbackTime = playbackTime;
 85 |       }
 86 |     }
 87 | 
 88 |     // Pause playback, keep track of where playback stopped
 89 |     this.pause = function() {
 90 |       this.stop(true);
 91 |     }
 92 | 
 93 |     // Stops or pauses playback and sets playbackTime accordingly
 94 |     this.stop = function(pause) {
 95 |       console.log("Stop");
 96 |       if (!this._isPlaying) return;
 97 |       this._isPlaying = false; // Set to flag to endOfPlayback callback that this was set manually
 98 |       this._source.stop(0);
 99 |       // If paused, calculate time where we stopped. Otherwise go back to beginning of playback (0).
100 |       this._playbackTime = pause ? (Date.now() - this._startTimestamp)/1000 + this._playbackTime : 0;
101 |     }
102 | 
103 |     // Callback for any time playback stops/pauses
104 |     this.endOfPlayback = function(endEvent) {
105 |       console.log("end of playback");
106 | 
107 |       // If playback stopped because end of buffer was reached
108 |       if (this._isPlaying) this._playbackTime = 0;
109 |       this._isPlaying = false;
110 |     }
111 | 
112 |     this.init = (function() {
113 |       this.initNewBuffer(this._buffer);
114 |     });
115 | 
116 |   };
117 | 
118 |   // Set BuffAudio on the global window object
119 |   window.BuffAudio = BuffAudio;
120 | 
121 | })(window);
122 | 


--------------------------------------------------------------------------------