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Re: Making a VU meter

From: Chris Wilson <cwilso@google.com>
Date: Wed, 13 Aug 2014 08:48:51 -0700
Message-ID: <CAJK2wqXwWOWeYY_zaQ1cXWyfBMQt38oBgSTHCwJ3d4Ff+aNnEw@mail.gmail.com>
To: Stephen Band <stephband@cruncher.ch>
Cc: Alan deLespinasse <adelespinasse@gmail.com>, "public-audio@w3.org" <public-audio@w3.org>
Alan - yeah, this is a handy technique.  You may want to use a WaveShaper
as a rectifier - that's what I did for the "envelope follower" in
https://webaudiodemos.appspot.com/input/index.html.  (that demo makes more
sense if you select "waveform" in the visualizer.)  Code here:
https://github.com/cwilso/Audio-Input-Effects/blob/master/js/effects.js#L739
.

And yes, we really need an envelope follower node, because in practice you
really want separate attack/release controls (the VU meter script processor
code I wrote has a crude release, but no attack control).  This is captured
in https://github.com/WebAudio/web-audio-api/issues/246, and related
https://github.com/WebAudio/web-audio-api/issues/13.
Received on Wednesday, 13 August 2014 15:49:22 UTC

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