├── LICENSE.txt
├── README.md
├── Rakefile
└── lib
    ├── WavAudioEncoder.js
    └── WavAudioEncoder.min.js


/LICENSE.txt:
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 1 | The MIT License (MIT)
 2 | 
 3 | Copyright (c) 2015 Yuji Miyane
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 | 


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/README.md:
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 1 | # WavAudioEncoder.js
 2 | 
 3 | ## What is it?
 4 | 
 5 | WavAudioEncoder.js is a small JavaScript library that encodes audio data to Waveform Audio (.wav) on web browsers.
 6 | 
 7 | ### Acknowledgement
 8 | 
 9 | Basic idea is taken from Recorderjs (<https://github.com/mattdiamond/Recorderjs>). API has been totally re-designed and simplified. Now it has been a lower layer part of [WebAudioRecorder.js](https://github.com/higuma/web-audio-recorder-js).
10 | 
11 | ## Demo
12 | 
13 | <https://higuma.github.io/wav-audio-encoder-js/>
14 | 
15 | ## Library files
16 | 
17 | `lib/` contains library files.
18 | 
19 | * `WavAudioEncoder.js`: JavaScript library (uncompressed)
20 | * `WavAudioEncoder.min.js`: JavaScript library (minified)
21 | 
22 | ### Using library
23 | 
24 | You can use it from both HTML and Web Worker.
25 | 
26 | * from HTML: `<script src="javascripts/WavAudioEncoder.js"></script>`
27 | * from Worker: `importScripts("javascripts/WavAudioEncoder.js");`
28 | 
29 | ## API
30 | 
31 | ``` javascript
32 | encoder = new WavAudioEncoder(sampleRate, numChannels)
33 | ```
34 | 
35 | Create an encoder object.
36 | 
37 | * Parameters
38 |     * `samleRate`: sampling rate [Hz]
39 |     * `numChannels`: number of audio channels
40 | * Returns
41 |     * encoder object
42 | 
43 | > In current implementation, bit width is fixed to 16 (2 bytes).
44 | 
45 | ``` javascript
46 | encoder.encode(buffers)
47 | ```
48 | 
49 | Encode audio buffers.
50 | 
51 | * Parameters
52 |     * `buffers`: array of sample buffers (`[Float32Array, Float32Array ...]`)
53 | * Returns
54 |     * (none)
55 | 
56 | `buffers` must be an array of Float32Array audio data (range = [-1, 1]). Array length must be same as number of channels. It supports stream (incremental) processing. Sample buffers are processed to .wav fragment and appended to internal data.
57 | 
58 | ``` javascript
59 | blob = encoder.finish([mimeType])
60 | ```
61 | 
62 | Finish encoding and get Waveform Audio as a Blob.
63 | 
64 | * Parameters
65 |     * `mimeType`(optional): MIME type (default = `"audio/wav"`)
66 | * Returns
67 |     * Blob object
68 | 
69 | After calling `.finish()`, all internal data is cleared. You must create a new encoder object to encode another audio data.
70 | 
71 | ``` javascript
72 | encoder.cancel()
73 | ```
74 | 
75 | * Parameters
76 |     * (none)
77 | * Returns
78 |     * (none)
79 | 
80 | Cancel encoding and clear all internal data.
81 | 
82 | ## License
83 | 
84 | MIT (see [LICENSE.txt](LICENSE.txt)).
85 | 


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/Rakefile:
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 1 | task :build_minified do
 2 |   sh 'uglifyjs -m sort lib/WavAudioEncoder.js > lib/WavAudioEncoder.min.js'
 3 | end
 4 | 
 5 | task :clean do
 6 |   sh 'rm -rf lib/WavAudioEncoder.min.js'
 7 | end
 8 | 
 9 | task default: :build_minified
10 | 
11 | __END__
12 | 
13 | task copy_files: :build_minified do
14 |   sh 'cp lib/* ../WebAudioRecorder.demo/src/js'
15 |   sh 'cp lib-minified/* ../WebAudioRecorder.demo/public/js'
16 | end
17 | 
18 | 


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/lib/WavAudioEncoder.js:
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 1 | (function(self) {
 2 |   var min = Math.min,
 3 |       max = Math.max;
 4 | 
 5 |   var setString = function(view, offset, str) {
 6 |     var len = str.length;
 7 |     for (var i = 0; i < len; ++i)
 8 |       view.setUint8(offset + i, str.charCodeAt(i));
 9 |   };
10 | 
11 |   var Encoder = function(sampleRate, numChannels) {
12 |     this.sampleRate = sampleRate;
13 |     this.numChannels = numChannels;
14 |     this.numSamples = 0;
15 |     this.dataViews = [];
16 |   };
17 | 
18 |   Encoder.prototype.encode = function(buffer) {
19 |     var len = buffer[0].length,
20 |         nCh = this.numChannels,
21 |         view = new DataView(new ArrayBuffer(len * nCh * 2)),
22 |         offset = 0;
23 |     for (var i = 0; i < len; ++i)
24 |       for (var ch = 0; ch < nCh; ++ch) {
25 |         var x = buffer[ch][i] * 0x7fff;
26 |         view.setInt16(offset, x < 0 ? max(x, -0x8000) : min(x, 0x7fff), true);
27 |         offset += 2;
28 |       }
29 |     this.dataViews.push(view);
30 |     this.numSamples += len;
31 |   };
32 | 
33 |   Encoder.prototype.finish = function(mimeType) {
34 |     var dataSize = this.numChannels * this.numSamples * 2,
35 |         view = new DataView(new ArrayBuffer(44));
36 |     setString(view, 0, 'RIFF');
37 |     view.setUint32(4, 36 + dataSize, true);
38 |     setString(view, 8, 'WAVE');
39 |     setString(view, 12, 'fmt ');
40 |     view.setUint32(16, 16, true);
41 |     view.setUint16(20, 1, true);
42 |     view.setUint16(22, this.numChannels, true);
43 |     view.setUint32(24, this.sampleRate, true);
44 |     view.setUint32(28, this.sampleRate * 4, true);
45 |     view.setUint16(32, this.numChannels * 2, true);
46 |     view.setUint16(34, 16, true);
47 |     setString(view, 36, 'data');
48 |     view.setUint32(40, dataSize, true);
49 |     this.dataViews.unshift(view);
50 |     var blob = new Blob(this.dataViews, { type: 'audio/wav' });
51 |     this.cleanup();
52 |     return blob;
53 |   };
54 | 
55 |   Encoder.prototype.cancel = Encoder.prototype.cleanup = function() {
56 |     delete this.dataViews;
57 |   };
58 | 
59 |   self.WavAudioEncoder = Encoder;
60 | })(self);
61 | 


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/lib/WavAudioEncoder.min.js:
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1 | (function(n){var a=Math.min,s=Math.max;var e=function(n,a,e){var s=e.length;for(var t=0;t<s;++t)n.setUint8(a+t,e.charCodeAt(t))};var t=function(t,e){this.sampleRate=t;this.numChannels=e;this.numSamples=0;this.dataViews=[]};t.prototype.encode=function(r){var t=r[0].length,u=this.numChannels,h=new DataView(new ArrayBuffer(t*u*2)),o=0;for(var e=0;e<t;++e)for(var n=0;n<u;++n){var i=r[n][e]*32767;h.setInt16(o,i<0?s(i,-32768):a(i,32767),true);o+=2}this.dataViews.push(h);this.numSamples+=t};t.prototype.finish=function(s){var n=this.numChannels*this.numSamples*2,t=new DataView(new ArrayBuffer(44));e(t,0,"RIFF");t.setUint32(4,36+n,true);e(t,8,"WAVE");e(t,12,"fmt ");t.setUint32(16,16,true);t.setUint16(20,1,true);t.setUint16(22,this.numChannels,true);t.setUint32(24,this.sampleRate,true);t.setUint32(28,this.sampleRate*4,true);t.setUint16(32,this.numChannels*2,true);t.setUint16(34,16,true);e(t,36,"data");t.setUint32(40,n,true);this.dataViews.unshift(t);var a=new Blob(this.dataViews,{type:"audio/wav"});this.cleanup();return a};t.prototype.cancel=t.prototype.cleanup=function(){delete this.dataViews};n.WavAudioEncoder=t})(self);
2 | 


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