At Mon, 20 Jun 2005 23:50:38 -0400,
Lee Revell wrote:
>
> On Mon, 2005-06-20 at 18:47 +0200, Takashi Iwai wrote:
> > The set-up is, however, not only the choice of the soundcard, but it
> > includes eventually the choice and set-up of devices. For example,
> > the default I/O should support 5.1 output or SPDIF if user wants (I'm
> > wondering why no one mentions about them.)
> >
>
> I think because the apps that want to use these (99% xine and mplayer)
> already seem to do the right thing.
Yes, but it's usually also exclusive. If any processes occupy the
device, 5.1 output can't be played. This may be a problem, e.g. if
you start a video player from a web browser.
But, switching 2.0 and 5.1 on the fly during the output is impossible
in many cases, too. Thus, we have to choose either 2.0 or 5.1 as the
system configuration, and let dmix running ether 2.0 or 5.1 mode.
Of course, there might be other problems with this. (Who on the earth
wants to hear beep with 5.1 speakers? ;)
> > Then (2), it's more about with JACK: I think the scenario above would
> > work indeed. We don't have a plugin to do such a job yet, but it
> > should be easy to create. Suppose a new plugin which have a
> > configuration like below:
> >
> > pcm.!default {
> > type sequential
> > pcms [ "dmix" "jack" ... ]
> > }
> >
> > so that it will try to open dmix, jack, etc sequentially until it
> > succeeds. Then non-JACK apps can work seamlessly, too, without
> > changing configuration.
> >
>
> This is a great idea, we should discuss it further on alsa-devel.
Agreed. Let's keep discussion there, then.
> In fact JACK works perfectly fine with or without dmix, it just
> complains loudly if you try to use it with the plug layer. We should
> preserve this behavior: JACK will first try to get exclusive access,
> then if only dmix is available, it should display a warning and
> continue.
I think this is relatively OK. It's just a warning and obviously the
plug layer prevents the optimal performance with JACK. And if JACK is
started automatically, user would notice it rarely, too...
Takashi
Received on Wed Jun 22 00:15:04 2005
This archive was generated by hypermail 2.1.8 : Wed Jun 22 2005 - 00:15:09 EEST