A jQuery plugin providing Voice Activity Detection (vad) and streaming access to microphone via Flash and event handling.

How

Simply attach the plugin to some DOM selector (var microphone = new $.microphone('#div', options);) and start listening to JQuery events (ready, data, event, vad, error).

Both start and stop method are used to activate and deactivate the microphone capture itself. Typically, start() is performed upon ready event, while stop() is either to be used following a setTimeout() or upon vad event type where e.activating === false.

As for the activity, it can be used for instead to monitor activity level ([0:100]) and show off a volume/activity meter of your own.

The plugin creates the HTML object underneat the selector and add the microphone css class to be styled for size, visibility and such.

Note that, as any Adobe Flash plugin requiring access to the microphone device, a user needs to accept access notice, and potentially configure the device itself.

Example

var options = {
  vad: {
      level: 10, 
      timeout: 2000
  }
};
// hook microphone object to some div element
// an <object> container will be created dynamically (215px x 138px)
// with a stylable .microphone css class
var microphone = new $.microphone('#div', options);
$('#div').on('ready', function(event){
  console.log('ready');
  // will stop after 10 sec.
  setTimeout(function(){
    microphone.stop();
  }, 10000);
  //starts streaming
  microphone.start();
});
//when samples are available, this function is called
$('#div').on('data', function(event, data){
  console.log(data);
});
// receive notification about voice activation detection
$('#div').on('vad', function(event, data){
  console.log(data);
});

Default Options

sampleRate : 8000,
codec : 'pcmu',
gain       : 50,
buffer_size : 4096,
swfPath    : 'microphone.swf',
vad: {
  level: 10,
  timeout: 2000
},
debugging  : true

Events

vad

This event is fired upon voice activity detection.

{
  activating: true,
  bubbles: false,
  cancelable: false,
  currentTarget: Object,
  eventPhase: 2,
  target: Object,
  type: "activity"
}

data

This event is fired once a frame buffer buffer has been filled or the microphone has been stopped. Buffer size is 4096.

{
  sample: Array[4096],
  timestamp: 1370219409273,
}

activity

This event is fired once for each frame sample received within the microphone Flash plugin. It may not be fired at continuous rate. Activity level values range between 0-100.

{
    "encodeQuality": 6,
    "useEchoSuppression": false,
    "noiseSuppressionLevel": -30,
    "enhancedOptions": null,
    "activityLevel": 5,
    "soundTransform": {
        "rightToRight": 1,
        "volume": 1,
        "pan": 0,
        "leftToRight": 0,
        "rightToLeft": 0,
        "leftToLeft": 1
    },
    "gain": 50,
    "silenceLevel": 10,
    "rate": 8,
    "silenceTimeout": 2000,
    "enableVAD": true,
    "codec": "pcmu",
    "name": "Default",
    "muted": false,
    "framesPerPacket": 2,
    "index": 0
}

status

This event is fired upon the user clicking either one of accept or reject from within the Flash settings privacy dialog.

{
  "level": "status",
  "code": "Microphone.Muted",
  "currentTarget": {
      "encodeQuality": 6,
      "useEchoSuppression": false,
      "noiseSuppressionLevel": -30,
      "enhancedOptions": null,
      "activityLevel": -1,
      "soundTransform": {
          "rightToRight": 1,
          "volume": 1,
          "pan": 0,
          "leftToRight": 0,
          "rightToLeft": 0,
          "leftToLeft": 1
      },
      "gain": 28,
      "silenceLevel": 10,
      "rate": 8,
      "silenceTimeout": 2000,
      "enableVAD": true,
      "codec": "pcmu",
      "name": "Default",
      "muted": true,
      "framesPerPacket": 2,
      "index": 0
  },
  "eventPhase": 2,
  "type": "status",
  "bubbles": false,
  "cancelable": false,
  ...
}

Building Flash Object

make swf

Note that you will need the flex builder command line tools from the SDK, which is available for free.

SWF Bridge

Communication between SWF object and Javascript itself is done through a bridge object ($.microphone.Bridge) which handles and properly dispatch events on the client side.

Todo

• Port back to original repository (requires backward compatibility with no jquery wrapper)
• Use callback for both ready and error instead of event. (Best practice)
• Fully document the option hash.

Contributors

• Morteza Milani (Original development)
• Pascal Deschenes (jQuery plugin, vad handling, and some bug fixes/cleanup)

License

(The MIT License) Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.