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Re: Some questions about JavaScriptNode

From: Yves Raimond <Yves.Raimond@bbc.co.uk>
Date: Mon, 19 Mar 2012 21:09:56 +0000
To: Raymond Toy <rtoy@google.com>
Cc: public-audio@w3.org
Message-ID: <20120319210956.GA30461@dvbstreamer.national.core.bbc.co.uk>
On Mon, Mar 19, 2012 at 12:51:14PM -0700, Raymond Toy wrote:
> On Mon, Mar 19, 2012 at 4:34 AM, Yves Raimond <Yves.Raimond@bbc.co.uk>wrote:
> 
> > Hello!
> >
> > I was recently wondering about a few aspects of JavascriptNode. I was
> > wondering why, in Chrome Linux, every demo involving sound generated by a
> > JavascriptNode was stuttering, e.g. [0]. It does look like the frequency of
> > the stutter changes as the size of the node buffer changes, which seems to
> > indicate that each silence is actually the time it takes to run the process
> > code. Demos involving just reading from a wavetable don't seem to suffer
> > from that. Of course a way around that would be to have an optimised
> > oscillator node, which has been discussed before on this mailing list.
> >
> 
> I believe this is an artifact of how chrome linux handles audio.  If you
> change kBufferSize to 2048, the tones will come out as expected.   There is
> an internal buffer of size 2048 and this causes the stuttering you see with
> a JavaScriptNode.  You need to generate at least 2048 samples.

You're absolutely right - setting the buffer size to 2048 samples gets rid of the stuttering - many thanks for that!

Best,
y

> 
> Ray
Received on Monday, 19 March 2012 21:10:26 GMT

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