Re: Maintaining sound card at a specific frequency

[Takashi Iwai <tiwai@suse.de>]

At Tue, 18 Jan 2005 18:31:28 +0100 (CET),
Giuliano Pochini wrote:
> 
> 
> 
> On Tue, 18 Jan 2005, Takashi Iwai wrote:
> 
> > > IMHO we should think on a good solution for this problem. Some
> > > cards have many channels/voices but the sample rate is common
> > > for all of them. Currently the only clean way to manage it is
> > > a control that locks the sample rate at a given frequency, but
> > > it isn't a nice solution because it requires explicit user
> > > intervention. In the echoaudio driver I implemented a kludge
> > > that automatically locks the sample frequency in order to avoid
> > > unwanted rate changes.
> >
> > You can add a control to lock the sample rate (e.g. ICE1712).
> 
> Yep, I know, but it's not part of the pcm API: applications do not
> lock the sample rate themselves. The user has to do it manually. This is
> why I choosed an alternate solution. If apps were able to lock the rate it
> would be very useful. It may need some help from the driver, though.

I think this is above the PCM API since this influences the whole
system.  It's fine to add a new API call in alsa-lib, just as a
wrapper to toggle such a  control, though...


Takashi


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