Draw audio waveform to a canvas using the Web Audio API
This is a small helper module that allows you to render a canvas to visualize audio from an audio or video element, or a getUserMedia stream. It uses the Web Audio API. This can be useful to display audio visually, or to track down when a video or audio element does not behave as you expect.
This was primarily written to work with the rtc-media library so here's an example of how it works there:
var media = ;var waveform = ;var localvideo = ;var videoElement = localvideo;var canvas = ;
This example shows how to pipe an audio file into the waveform display. The canvas will be added to the body element unless you provide a different element to attach it to.
var waveform = ;var audio = 'examples/media/Hydrate-Kenny_Beltrey.ogg';var canvas = ;audio;
This example shows how to create a waveform display for a video element. It also shows how to attach the waveform to a separate element.
var waveform = ;var body = document0;var div = document;var video = document;videosrc = 'examples/media/sintel_trailer.webm';videocontrols = 'controls';body;body;var canvas = ;video;
You can use beefy to run the examples, e.g.
$ beefy examples/rtc-media.js
Copyright 2013 National ICT Australia Limited (NICTA)
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