Re: PCM API questions

[Takashi Iwai <tiwai@suse.de>]

At Mon, 24 Jun 2002 10:17:08 -0400,
Paul Davis wrote:
> 
> >the names above are not defined on all cards (except for default).
> >i think we need a kind of config database for each card.
> >this is useful not only for pcm but also for parsing the mixer
> >structure.
> 
> i think this is the wrong solution. i believe the correct solution is
> to provide a **simple** way to get every defined PCM device name.
> 
> a config database for cards doesn't cover multi devices, or channel
> subsets, or share devices, etc. etc.
 
that's right.  (but i think it's not a bad idea to put something more
descriptive for each pcm device which is card-specific.)

regarding to the device listing:
afaik, you can look up all pcm devices by calling
	snd_config_search(config, "PCM", &conf)
and then run snd_config_for_each()...  ah, not SIMPLE as you wrote.

so, making a list of pcm names would be relatively easy.  we can add a
new function to alsa-lib.

but arising problem is that this will list up all possible
definitions.  that is, it will include the standard pcm names with
arguments such as hw or plughw.  it's not bad (you can use them even
without arguments) but maybe confusing.

anyway it would be nice to add a "description" entry for each
definition in the config, so that it will appear on the list more
intuitively.


Takashi


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