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Microphone-analyzer

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microphone-analyzer

microphone-analyzer is a polymer element that enables document microphone input data analysis.

Dependencies:

Polymer
ddcast/microphone (fork of srubin/microphone)

Install

Command line:

bower install ddcast/microphone-analyzer

Include in your document <head>:

<script src="components/platform/platform.js"></script>
<script src="components/microphone/microphone.js"></script>

<link rel="import" href="components/polymer/polymer.html"> 
<link rel="import" href="components/microphone-analyzer/microphone-analyzer.html">

Release notes

beta-0.0.3
- startStream api method now reconnects stream at JavaScriptNode.
beta-0.0.2
- Improved element lifecycle management.
- Included fork of srubin/microphone that patches issue around multiple AudioContext instances.
- Added api methods killStream and startStream which respectively disconnects and connects media and processing node streams.

Usage

The air event is fired at the interaval specified by the length option. event.detail will contain the following properties:

data: audio stream data
rms: current root mean square
value: rms value
audioRange: descriptive range of current volume level (based on matched <audio-range>)
- index: index of matched <audio-range> element
- innerHTML: markup or text
- value: range array

Element attributes (based on srubin/microphone):

length: the length (in seconds) of audio to return in each callback (default: .5)
overlap: the amount of overlap in the audio data between successive callbacks (For example, overlap of .25 means the last 25% of the audio data from one callback will be the first 25% of the data in the next callback). (default: .5. Must be between 0 and 1, inclusive)
channels: 1 (mono) or 2 (stereo) (default: 1)

Example

HTML:

<microphone-analyzer length=".5" overlap=".25" channels="1">
  <audio-range start="0" end="1"><em>speak up!</em></audio-range>
  <audio-range start="1.01" end="2">quiet</audio-range>
  <audio-range start="2.01" end="3">normal</audio-range>
  <audio-range start="3.01" end="4">loud</audio-range>
  <audio-range start="4.01" end="5">very loud</audio-range>
</microphone-analyzer>

JavaScript:

var microphoneAnalyzer = document.querySelector('microphone-analyzer');

microphoneAnalyzer.valuefilter = function (rms) {
  var vol = rms * 100;

  return vol;
};

microphoneAnalyzer.addEventListener('air', function(e) {
  console.log(e.detail.value);
});