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Re: Multi-channel hardware support available for testing in Chrome Canary

From: Jory <me@jory.org>
Date: Thu, 14 Mar 2013 23:11:29 -0700
To: public-audio-dev@w3.org
Message-ID: <20130314231129239063.fc96d6a4@jory.org>
On Thu, 14 Mar 2013 15:53:50 -0700, Chris Rogers wrote:
> For those interested in multi-channel output in the Web Audio API, here's
> your chance to try out an early build.  This could be of interest for
> digital DJ type applications, or rendering to multi-channel speaker
> installations...
> 
> Please note this is an early build and little testing has yet been made.
>  So far I've tested on several devices on OSX.  I'm interested in your
> feedback!
> 
> The .maxChannelCount attribute is now exposed to show the actual number of
> hardware channels:
> 
https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#AudioDestinationNode
> 
> The .channelCount attribute should now be settable on the
> AudioDestinationNode to values up to .maxChannelCount
> 
> Cheers,
> Chris

Well, I've spent a couple hours playing around, since multichannel 
audio certainly interests me, both for games and music. I've had very 
little success, though.

I'm finding it very difficult to get any audio to play out anything but 
the Left and Right channels. The only success I've had was forcing a 
down-mix to 1 channel, where sound finally came out my Center channel. 
So clearly the system functions in some manner. I've tried setting up a 
3D panner and hard-coding positional panning, but sound never leaves my 
Lft-Rht channels.

I also tried playing back a 6-channel interleaved WAV file, but while 
the file appears to "play", sound doesn't come from any speaker, no 
matter how I try to configure the channelCount.

I'm beginning to wonder if 6-channel source files are playable at this 
time or if that's unsupported. (Everything seems to have choked when I 
supplied a 6-channel AAC file, but I'm not even 100% the file I 
supplied was even playable, since getting multi-channel AAC output is 
kinda challenging with today's tools.) Also, a bit of sample code would 
do my morale wonders right about now. :-)

Thanks!

Jory

me@jory.org
http://studio.jory.org
Received on Friday, 15 March 2013 06:11:58 GMT

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