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Re: Web Audio API questions and comments

From: Raymond Toy <rtoy@google.com>
Date: Tue, 19 Jun 2012 11:37:59 -0700
Message-ID: <CAE3TgXHhUYjwjtMtPsDEnDtQZM3W8OsNb5jzhKkdFnMK+QzDtg@mail.gmail.com>
To: Joe Turner <joe@oampo.co.uk>
Cc: Chris Wilson <cwilso@google.com>, public-audio@w3.org
On Tue, Jun 19, 2012 at 10:01 AM, Joe Turner <joe@oampo.co.uk> wrote:

> Hey Chris,
> Thanks for the reply,
>
> On Tue, Jun 19, 2012 at 5:34 PM, Chris Wilson <cwilso@google.com> wrote:
> > Hey Joe - I can respond to a couple of these.
> >
> > On Tue, Jun 19, 2012 at 7:39 AM, Joe Turner <joe@oampo.co.uk> wrote:
> >>
> >> - Operator nodes, AudioParam nodes
> >>
> >> Can we have separate nodes for the basic mathematical operators (add,
> >> subtract, divide, multiply and modulo), and a way of having the output
> >> of an AudioParam as a signal?  This would allow all the flexibility
> >> needed for scaling, offsetting and combining signals in order to
> >> control parameters.  I know a bit of trickery can make stuff like this
> >> possible at the moment, and it's trivial to implement in JavaScript,
> >> but it seems like core functionality to me.
> >
> >
> > Actually, you should be able to do all of these operations by either
> > connecting nodes together (add and subtract - might need a waveshaper to
> > flip phase for subtract), using gainNodes (multiply and divide) - not
> sure
> > about how you'd use modulo.
> >
>
> Yeah - it just seems a little ugly having to use waveshapers for
> subtraction, and a scaled non-oscillating oscillator to add a dc
>

For subtraction, I think I'd use an AudioGainNode with a gain of -1.


> offset to a signal.  Operator nodes and some way of outputting
>
>
A DC offset can also be done using a JavaScriptAudioNode.

Ray
Received on Tuesday, 19 June 2012 18:38:29 GMT

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