[alsa-devel] [RFC] Channel mapping API

David Henningsson david.henningsson at canonical.com
Tue Aug 21 17:38:28 CEST 2012

On 08/21/2012 05:07 PM, Mark Brown wrote:
> On Tue, Aug 21, 2012 at 04:52:29PM +0200, David Henningsson wrote:
>> On 08/21/2012 04:18 PM, Mark Brown wrote:
>>> Or perhaps what we want to do here is define the channel mapping in
>>> terms of saying "I'm connecting to this input/output" and then use the
>>> jack interface to describe all inputs and outputs rather than just jacks
>>> (making sure it's easy to see which ones can change state)?
>> That's an interesting idea. The possible drawback is that it would
>> require all drivers that want to use this to implement jacks also.
> I'm not sure that's a big deal, we should be able to make the fixed data
> case easy enough to do.
>> In the ctljack interface for HDA, we already describe all inputs and
>> outputs - with the nonchangable ones having the additional "Phantom"
>> suffix, so the result becomes e g "Internal Mic Phantom Jack".
> Which of course is also replicated with the calls into the original
> jack API.

Actually, the phantom jacks are only in the ctljack API. I deliberately 
left them out of the old jack API, because it was deprecated (or at 
least so I thought).

David Henningsson, Canonical Ltd.

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