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Re: Audio-ISSUE-95 (ChannelLayouts): Channel Layouts are not sufficiently defined [Web Audio API]

From: Marcus Geelnard <mage@opera.com>
Date: Tue, 22 May 2012 09:09:02 +0200
To: "olivier Thereaux" <olivier.thereaux@bbc.co.uk>, "Chris Rogers" <crogers@google.com>
Cc: "Audio Working Group" <public-audio@w3.org>
Message-ID: <op.weo7hcpum77heq@mage-desktop>
Den 2012-05-21 22:10:10 skrev Chris Rogers <crogers@google.com>:

> On Mon, May 21, 2012 at 6:29 AM, olivier Thereaux  
> <olivier.thereaux@bbc.co.uk> wrote:
>
>> My understanding of the consensus so far was that:
>>
>> * The API should support and (by default) match the channel  
>> configuration specified by the hardware
>>
>
> I've proposed a way to deal with multi-channel output for
> AudioDestinationNode here:
> https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#AudioDestinationNode

The maxNumberOfChannels attribute does not seem to be enough (and I'm not  
sure that the magic "0" value is a good solution).

For example, consider some hardware that is only capable of stereo output  
(unlikely, but equivalent to a fixed channel layout offline context I  
guess): The only valid value for numberOfChannels would be 2 (1 would be  
"out of range"). As another example, let's assume that some hardware  
supports Mono, Stereo and 5.1. What should happen if you set  
numberOfChannels to 3?

A simple solution comes to mind:

     sequence<unsigned int> getSupportedChannelCounts(); // Returns a  
sequence of valid channel configurations (e.g. [1,2,6]).



/Marcus
Received on Tuesday, 22 May 2012 07:10:00 GMT

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