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Re: specific demos wanted, question about media streams processing api

From: Robert O'Callahan <robert@ocallahan.org>
Date: Mon, 26 Mar 2012 16:08:17 +1300
Message-ID: <CAOp6jLaOxQp99X2G63ofrJjmoXOf2aw8HcucAE8VtHEmFEEe=g@mail.gmail.com>
To: Samuel Goldszmidt <samuel.goldszmidt@ircam.fr>
Cc: public-audio@w3.org
On Fri, Mar 23, 2012 at 11:23 PM, Samuel Goldszmidt <
samuel.goldszmidt@ircam.fr> wrote:

>  - full fft implementation in javascript (is this one up to date ?
> https://wiki.mozilla.org/Audio_Data_API)
> - full convolution engine implementation in javascript too.
> using both of the 2 apis ( Web audio api and media streams processing api)
>

I haven't ported any Audio Data FFT or convolution examples to MediaStreams
but it wouldn't be hard.


> - a sort of offline processing with media streams processing api, to
> represent waveform (I know with the comparison of the 2 api in the wiki,
> that "offline" processing in media streams could be more difficult to
> achieve, that's why I'm looking for this kind of demo)
>

I'm not quite sure what you mean by "offline processing". I think you
probably mean the ability to construct a stream graph and drive it at the
maximum possible speed to record a composition or something like that.

As far as I can tell, neither Web Audio or MediaStreams Processing supports
that currently. (The comparison wiki page
http://www.w3.org/2011/audio/wiki/Spec_Differences says Web Audio does, but
I don't see API for it on AudioContext in
https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#AudioContext-section
.)

I think there's nothing difficult in principle about adding API for this to
either proposal. Since MediaStreams Processing doesn't have a context
object, I would just add an API to MediaStream that controls the processing
rate of the entire connected subgraph.

Rob
-- 
“You have heard that it was said, ‘Love your neighbor and hate your enemy.’
But I tell you, love your enemies and pray for those who persecute you,
that you may be children of your Father in heaven. ... If you love those
who love you, what reward will you get? Are not even the tax collectors
doing that? And if you greet only your own people, what are you doing more
than others?" [Matthew 5:43-47]
Received on Monday, 26 March 2012 03:08:47 GMT

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