├── .gitignore
├── .jshintignore
├── .jshintrc
├── README.md
├── build.js
├── mediastream-gain.bundle.js
├── mediastream-gain.js
├── package.json
└── test.html


/.gitignore:
--------------------------------------------------------------------------------
1 | .DS_Store
2 | node_modules
3 | 


--------------------------------------------------------------------------------
/.jshintignore:
--------------------------------------------------------------------------------
1 | node_modules
2 | *.bundle.js
3 | 


--------------------------------------------------------------------------------
/.jshintrc:
--------------------------------------------------------------------------------
 1 | {
 2 |     "asi": false,
 3 |     "expr": true,
 4 |     "loopfunc": true,
 5 |     "curly": false,
 6 |     "evil": true,
 7 |     "white": true,
 8 |     "undef": true,
 9 |     "browser": true,
10 |     "node": true,
11 |     "trailing": true,
12 |     "indent": 4,
13 |     "latedef": true,
14 |     "newcap": true
15 | }
16 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # mediastream-gain 
 2 | 
 3 | ## What is this?
 4 | 
 5 | A tiny browser module for creating a gain/volume controller for the audio channels in a [MediaStream](https://developer.mozilla.org/en-US/docs/WebRTC/MediaStream_API).
 6 | 
 7 | It's useful for controlling the volume of your microphone input before it's sent accross a peer connection in a WebRTC call, for example. This module is a small part of [SimpleWebRTC](http://simplewebrtc.com) where it is used for minimizing echos, by using [hark](http://latentflip.com/hark) to determine if you're speaking and turning your mic down a bit if you're not.
 8 | 
 9 | This module is suitable for use with [browserify](http://browserify.org)/CommonJS on the client. 
10 | 
11 | If you're not using browserify or you want AMD support use `mediastream-volume.bundle.js`.
12 | 
13 | 
14 | ## Important details
15 | 
16 | The way this works by replacing the first audio channel in the stream with one that is run through a gain filter. But beware that this *edits the stream you give it in place* it doesn't produce a new one.
17 | 
18 | 
19 | ## Installing
20 | 
21 | ```
22 | npm install mediastream-gain
23 | ```
24 | 
25 | ## An example
26 | 
27 | Here we use another piece of SimpleWebRTC [getusermedia](https://github.com/HenrikJoreteg/getusermedia) to fetch user media in a cross-browser, easy-to-handle-errors-and-lack-of-support sort of way. 
28 | 
29 | This assumes a commonJS environment, but that's not a requirement (see above).
30 | 
31 | ```js
32 | var MicGainController = require('mediastream-gain');
33 | var getUserMedia = require('getusermedia');
34 | var gainController;
35 | 
36 | getUserMedia(function (err, stream) {
37 |     // this will replace the audio channels in the 
38 |     // stream
39 |     gainController = new MicGainController(stream);
40 |     // set gain to 20%
41 |     gainControl.setGain(.2);
42 |     // set gain to 0, effectively muting it
43 |     gainControl.setGain(0); 
44 |     // there's also:
45 |     gainControl.off(); // equivalent to setGain(0)
46 |     gainControl.on(); // equivalent to setGain(1)
47 | });
48 | 
49 | ```
50 | 
51 | ## Methods
52 | 
53 | It couldn't be simpler, but behavior varies slighly based on availability of WebAudio support that can be wired into WebRTC.
54 | 
55 | You can check for support by checking the `support` property of the an instance of `gainController`
56 | 
57 | These will simply be noop functions if WebAudio isn't fully supported. 
58 | 
59 | **.setGain(Float)** - takes a number between 1 and 0
60 | **.getGain()** - returns current setting
61 | **.off()** - shortcut for turning mic off 
62 | **.on()** - shortcut for full gain
63 | 
64 | 
65 | ## License
66 | 
67 | MIT
68 | 
69 | ## Created By
70 | 
71 | If you like this, follow: [@HenrikJoreteg](http://twitter.com/henrikjoreteg) on twitter.
72 | 
73 | 


--------------------------------------------------------------------------------
/build.js:
--------------------------------------------------------------------------------
1 | var bundle = require('browserify')();
2 | var fs = require('fs');
3 | 
4 | bundle.add('./mediastream-gain');
5 | bundle.bundle({standalone: 'MediaStreamGainController'}).pipe(fs.createWriteStream('mediastream-gain.bundle.js'));
6 | 


--------------------------------------------------------------------------------
/mediastream-gain.bundle.js:
--------------------------------------------------------------------------------
 1 | !function(e){"object"==typeof exports?module.exports=e():"function"==typeof define&&define.amd?define(e):"undefined"!=typeof window?window.MediaStreamGainController=e():"undefined"!=typeof global?global.MediaStreamGainController=e():"undefined"!=typeof self&&(self.MediaStreamGainController=e())}(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);throw new Error("Cannot find module '"+o+"'")}var f=n[o]={exports:{}};t[o][0].call(f.exports,function(e){var n=t[o][1][e];return s(n?n:e)},f,f.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
 2 | var support = require('webrtcsupport');
 3 | 
 4 | 
 5 | function GainController(stream) {
 6 |     this.support = support.webAudio && support.mediaStream;
 7 | 
 8 |     // set our starting value
 9 |     this.gain = 1;
10 | 
11 |     if (this.support) {
12 |         var context = this.context = new support.AudioContext();
13 |         this.microphone = context.createMediaStreamSource(stream);
14 |         this.gainFilter = context.createGain();
15 |         this.destination = context.createMediaStreamDestination();
16 |         this.outputStream = this.destination.stream;
17 |         this.microphone.connect(this.gainFilter);
18 |         this.gainFilter.connect(this.destination);
19 |         stream.addTrack(this.outputStream.getAudioTracks()[0]);
20 |         stream.removeTrack(stream.getAudioTracks()[0]);
21 |     }
22 |     this.stream = stream;
23 | }
24 | 
25 | // setting
26 | GainController.prototype.setGain = function (val) {
27 |     // check for support
28 |     if (!this.support) return;
29 |     this.gainFilter.gain.value = val;
30 |     this.gain = val;
31 | };
32 | 
33 | GainController.prototype.getGain = function () {
34 |     return this.gain;
35 | };
36 | 
37 | GainController.prototype.off = function () {
38 |     return this.setGain(0);
39 | };
40 | 
41 | GainController.prototype.on = function () {
42 |     this.setGain(1);
43 | };
44 | 
45 | 
46 | module.exports = GainController;
47 | 
48 | },{"webrtcsupport":2}],2:[function(require,module,exports){
49 | // created by @HenrikJoreteg
50 | var prefix;
51 | var isChrome = false;
52 | var isFirefox = false;
53 | var ua = window.navigator.userAgent.toLowerCase();
54 | 
55 | // basic sniffing
56 | if (ua.indexOf('firefox') !== -1) {
57 |     prefix = 'moz';
58 |     isFirefox = true;
59 | } else if (ua.indexOf('chrome') !== -1) {
60 |     prefix = 'webkit';
61 |     isChrome = true;
62 | }
63 | 
64 | var PC = window.mozRTCPeerConnection || window.webkitRTCPeerConnection;
65 | var IceCandidate = window.mozRTCIceCandidate || window.RTCIceCandidate;
66 | var SessionDescription = window.mozRTCSessionDescription || window.RTCSessionDescription;
67 | var MediaStream = window.webkitMediaStream || window.MediaStream;
68 | var screenSharing = window.navigator.userAgent.match('Chrome') && parseInt(window.navigator.userAgent.match(/Chrome\/(.*) /)[1], 10) >= 26;
69 | var AudioContext = window.webkitAudioContext || window.AudioContext;
70 | 
71 | 
72 | // export support flags and constructors.prototype && PC
73 | module.exports = {
74 |     support: !!PC,
75 |     dataChannel: isChrome || isFirefox || (PC && PC.prototype && PC.prototype.createDataChannel),
76 |     prefix: prefix,
77 |     webAudio: !!(AudioContext && AudioContext.prototype.createMediaStreamSource),
78 |     mediaStream: !!(MediaStream && MediaStream.prototype.removeTrack),
79 |     screenSharing: !!screenSharing,
80 |     AudioContext: AudioContext,
81 |     PeerConnection: PC,
82 |     SessionDescription: SessionDescription,
83 |     IceCandidate: IceCandidate
84 | };
85 | 
86 | },{}]},{},[1])
87 | (1)
88 | });
89 | ;


--------------------------------------------------------------------------------
/mediastream-gain.js:
--------------------------------------------------------------------------------
 1 | var support = require('webrtcsupport');
 2 | 
 3 | 
 4 | function GainController(stream) {
 5 |     this.support = support.webAudio && support.mediaStream;
 6 | 
 7 |     // set our starting value
 8 |     this.gain = 1;
 9 | 
10 |     if (this.support) {
11 |         var context = this.context = new support.AudioContext();
12 |         this.microphone = context.createMediaStreamSource(stream);
13 |         this.gainFilter = context.createGain();
14 |         this.destination = context.createMediaStreamDestination();
15 |         this.outputStream = this.destination.stream;
16 |         this.microphone.connect(this.gainFilter);
17 |         this.gainFilter.connect(this.destination);
18 |         stream.addTrack(this.outputStream.getAudioTracks()[0]);
19 |         stream.removeTrack(stream.getAudioTracks()[0]);
20 |     }
21 |     this.stream = stream;
22 | }
23 | 
24 | // setting
25 | GainController.prototype.setGain = function (val) {
26 |     // check for support
27 |     if (!this.support) return;
28 |     this.gainFilter.gain.value = val;
29 |     this.gain = val;
30 | };
31 | 
32 | GainController.prototype.getGain = function () {
33 |     return this.gain;
34 | };
35 | 
36 | GainController.prototype.off = function () {
37 |     return this.setGain(0);
38 | };
39 | 
40 | GainController.prototype.on = function () {
41 |     this.setGain(1);
42 | };
43 | 
44 | 
45 | module.exports = GainController;
46 | 


--------------------------------------------------------------------------------
/package.json:
--------------------------------------------------------------------------------
 1 | {
 2 |   "name": "mediastream-gain",
 3 |   "description": "cross-browser getUserMedia shim with node.js style error-first API.",
 4 |   "version": "1.0.1",
 5 |   "author": "Henrik Joreteg <henrik@andyet.net>",
 6 |   "dependencies": {
 7 |     "webrtcsupport": "^1.0.0"
 8 |   },
 9 |   "devDependencies": {
10 |     "attachmediastream": "1.0.1",
11 |     "browserify": "2.x",
12 |     "getusermedia": "0.2.1",
13 |     "precommit-hook": "0.3.x"
14 |   },
15 |   "keywords": [
16 |     "browser",
17 |     "getUserMedia",
18 |     "WebRTC",
19 |     "microphone",
20 |     "webaudio"
21 |   ],
22 |   "license": "MIT",
23 |   "main": "mediastream-gain.js",
24 |   "repository": {
25 |     "type": "git",
26 |     "url": "https://github.com/HenrikJoreteg/mediastream-gain"
27 |   }
28 | }
29 | 


--------------------------------------------------------------------------------
/test.html:
--------------------------------------------------------------------------------
 1 | <!DOCTYPE html>
 2 | <html>
 3 |     <head>
 4 |         <title>mediastream-gain</title>
 5 |     </head>
 6 |     <body>
 7 |         <video id="local" width="200"></video>
 8 |         <br>
 9 |         <button onclick="gainController.setGain(1)">gainController.setGain(1)</button>
10 |         <button onclick="gainController.setGain(0)">gainController.setGain(0)</button>
11 |         <button onclick="gainController.setGain(.5)">gainController.setGain(.5)</button>
12 |         <button onclick="gainController.off()">gainController.off()</button>
13 |         <button onclick="gainController.on()">gainController.on()</button>
14 |         <script src="node_modules/getusermedia/getusermedia.bundle.js"></script>
15 |         <script src="node_modules/attachmediastream/attachmediastream.bundle.js"></script>
16 |         <script src="mediastream-gain.bundle.js"></script>
17 |         <script>
18 |             getUserMedia(function (err, stream) {
19 |                 if (err) {
20 |                     console.log(err);
21 |                 } else {
22 |                     attachMediaStream(stream, document.getElementById('local'));
23 |                     window.gainController = new MediaStreamGainController(stream);
24 |                 }
25 |             });
26 |         </script>
27 |     </body>
28 | </html>
29 | 


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