web-audio-analyser
v2.0.1
Published
A thin wrapper around the Web Audio API that lets you take some audio and get its waveform/frequency data in return.
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web-audio-analyser
A thin wrapper around the Web Audio API that lets you take some audio and get its waveform/frequency data in return.
Note: If you are streaming from SoundCloud or a similar API, you may need to set up CORS on your Audio source like so:
var audio = new Audio()
audio.crossOrigin = 'Anonymous'
audio.src = url
Usage
analyser = require('web-audio-analyser')(audio[, ctx][, opts])
Takes some form of audio
as the first argument. This may be one of the
following:
- An
<audio>
element. - A
MediaStream
object created by callinggetUserMedia
. - Any kind of
AudioSourceNode
.
Optionally, you can pass in your own AudioContext
instance too. Note there
may only be one instance of this per page, and if not supplied one will be
created for you.
You can also use the following options:
stereo
: retrieve separate data from the left and right audio channels.audible
: whether or not to play the audio you're analysing. Defaults totrue
, but set this tofalse
to disable. You can useanalyser.output
to pass the resulting output elsewhere.
analyser.waveform([ui8array][, channel])
Copies the audio's current time-domain data into a Uint8Array
. If you don't
pass your own in, one will be created for you: this will be reused, so it's
safe to call in an animation loop.
If you've enabled the stereo
option, you should pass channel
as either
0
or 1
to retrieve output from the left and right channels respectively.
analyser.frequencies([ui8array][, channel])
Much like analyser.waveform
, with the exception of copying the audio's
currrent frequency data into a Uint8Array
.