[pulseaudio-discuss] Pulseaudio alsa configure hook

Sjoerd Simons sjoerd at luon.net
Mon Apr 28 02:57:35 PDT 2008

On Mon, Apr 28, 2008 at 09:53:05AM +0100, Colin Guthrie wrote:
> Sjoerd Simons wrote:
> >   The attached patch extends the alsa pulse plugin set with a alsa
> >   configuration hook. Allowing one to specify some configuration parameters
> >   that only come into effect when pulseaudio is running.
> I was waiting with baited breath after your chat on IRC as to what your
> solution would actually be!
> I like it!
> I think the overhead at initialisation is probably OK, although I guess
> it depends on how an application works - e.g. if it constant opens and
> closes alsa connections then does this overhead mount up? If not then
> this looks like a good solution.

It unfortunately does add up. Otoh apps shouldn't open and close the audio
device all the time :) And ideally should use pulseaudio directly.

If i look at my personal desktop the only thing i actually still use that does
uses pulse through alsa is VLC.. Which will have a pulse output option in the
next release.

If people are getting hit by the overhead they can disable the check and
configure things manually. I think it's not too much of an overhead, but that's
something only practise can show when people start using it in different
situations. My feeling is that if your in a situation where the overhead gets
noticible then your probably skilled enough to change the configuration :)

> That said Lennart has said in the past that he didn't like the idea of
> Alsa  automatically falling back to h/w access if pulse isn't
> responding. (this was in reference to tweaking the alsa plugin itself,
> rather than this approach which is slightly different conceptually,
> albeit with the same end goal). I think his comment at the time was "it
> masks configuration problems".

Resource-wise you could theoretically fallback in nicer ways. But that requires
a lot more alsa knowledge then i have. The real issue is that there is no good
way to decide between, ``this user doesn't use pulse'' and ``this user wants to
use pulse but some problem occured''

What i'm currently unsure of is that the patch only declares pulse as running
if it succeeds in getting a full connection. Maybe, to be sure we don't hide
certain problems it should also declare pulse as running even if say
authentication fails.

Round Numbers are always false.
		-- Samuel Johnson

More information about the pulseaudio-discuss mailing list