[alsa-devel] Sample format changes by plugin while playing

[Ricard Wanderlof]

On Thu, 19 Apr 2018, Robert Tiemann wrote:

> 
> On 04/19/2018 03:53 PM, Clemens Ladisch wrote:
> 
> >> Is it possible for an ALSA plugin to reconfigure the sample rate and
> >> sample format of its slave in such a way that the software playing
> >> through that plugin wouldn't notice?
> > 
> > In theory, yes.  But you'd have to implement most of this yourself.
> 
> That's fine, I just wanted to know if this could possibly work and if
> an ALSA plugin could be the right place for this kind of stuff. That
> is, before diving into development and hitting any roadblocks only
> much later.

I'm curious about this. Do you have a need to reconfigure the sample rate 
and format while a stream is playing? We had such a use case a while ago, 
where we had a source whose sample rate could change at any time, but ALSA 
sets up the stream configuration (sample rate etc) when the stream is 
opened (hw_params()) and it doesn't seem to be possible to reconfigure it 
on the fly. In the end we dropped the idea and solved the problem a 
different way.

/Ricard
-- 
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30