[mythtv-users] ALSA No Longer Sees Sound Card
Mark Knecht
markknecht at gmail.com
Sun Mar 9 19:17:41 UTC 2008
On Sun, Mar 9, 2008 at 12:06 PM, Roger Heflin <rogerheflin at gmail.com> wrote:
> Michael T. Dean wrote:
> > On 03/09/2008 08:59 AM, Roger Heflin wrote:
> >> I had to rmmod the capture device before starting X so it would find the correct
> >> device, I also had to change myth to using /dev/dsp1 (I don't understand why
> >> /dev/dsp is not there), after that you can put the module for the capture device
> >> back.
> >>
> >> It does appear that the newer alsa are not quite smart enough to figure out that
> >> a capture device with only inputs should not be the default device,
> >
> > ALSA doesn't really choose the default device (other than to say that
> > whatever card has number 0 is the default). The kernel provides
> > numbers, so in effect, it chooses the default.
>
> I am not sure ALSA should be trusting the kernel to load the audio modules in
> the proper order for ALSA's use. ALSA should probably have a better way to pick
> the default device, their current scheme works perfectly fine when there were
> only a very few devices that looked like proper sound devices and it was fairly
> unlikely for someone to have more than one in a system, but given all of the new
> devices (usb camera, capture cards, ...) with kernel drivers that make them look
> like a proper sound device, a large number of users are going to run into this
> issue and be unable to figure it out. Mine broke on a kernel upgrade because
> the camera driver got loaded before the sounds cards driver.
>
Alsa has this. Please see my previous post or read the documentation
on the and of the Alsa sites about defining this stuff in
modules.conf.
http://alsa.opensrc.org/index.php/MultipleCards
The important thing is NONE of this is black magic. It may be arcane
but it's completely definable. I've had as many as 4 sound cards in
different machines and have had complete control for years using
modules.conf directly or indirectly.
hope this helps,
Mark
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