Ubuntu and Multimedia (audio, in particular)

[crimsun at fungus.sh.nu]

On Wed, Jan 11, 2006 at 09:01:03AM +0800, Michael Richter wrote:
[..]
> Ubuntu recognises both sound systems and loads drivers for them.  It then
> plays setup games so damned frustrating that it basically renders my system
> completely worthless as a multimedia platform.  Here's what happens.

After ensuring that your USB device is plugged in, open a Terminal
(Applications> Accessories> Terminal) and reply with output from the
following command:

$ cat /proc/asound/cards

If you are unlucky enough to have a USB Sound Blaster "24-bit"/"7.1",
things will be a bit more ... interesting.

> 1) Despite my setting the default sound card in System->Preferences->Sound
> to my Sound Blaster, the only thing that reliably plays sounds out to the
> Sound Blaster are the system event notifications.  I get nice, loud, clear
> sound events going out to my speakers for GAIM and for menus opening and
> closing, not to mention sporadically (yes, sporadically) getting sounds when
> windows open and close.

Perchance did you modify ~/.asoundrc or /etc/asound.conf manually (more
specifically, did you remove the ### markers)? If so, using System>
Preferences> Sound> Set default sound card will be ineffectual.

The symptoms that you describe are known issues for chipsets that don't
support pcm multiplexing in hardware (the SB non-24-bit/7.1 Lives and
Audigys do). Such hardware ranges from older ISA sound cards to the
modern "Intel High Definition Audio" cards. These cards must be
configured to use a software multiplexer. In Ubuntu Breezy this role is
performed by the underlying sound library coupled to the sound driver
(otherwise known as ALSA) through a plugin called "dmix." Depending
whether your onboard sound chipset is registered as card 0 according to
the output from the command above, you should be able to test whether
dmix (which allows you to play simultaneous sounds as Windows does in
software) is working for both cards:

$ aplay -Dplug:dmix /usr/share/sounds/startup.wav

The above command tests dmix for whatever card you've configured to be
the default. Under normal circumstances card 0 is the default, but you
may adjust that using the ``set-default-soundcard'' script (which is
really what System> Preferences> Sound> Set default sound card invokes
behind the scenes).

[..]
> Now some practical questions:
> 
>    - How do I tell Ubuntu to ignore the damned internal sound card once
>    and for all?  You know, to pretend the thing isn't even there?  To not even
>    load the drivers for it?  I suspect that would save me from the "randomly
>    switching between sound cards" problem.

More than likely what's happening is your USB sound device is second,
or card 1. See output from the first command. If that's the case, you
need to switch the order of the cards.

I need to see output from that command first, though.

>    - How do I persuade Totem that the sound card it just used a few
>    seconds ago without any difficulties isn't suddenly unavailable?

The answer to this question, too, depends on output from that command.

>    - How do I find out what the big difference is between the files that
>    make Totem choke and the files which only make Totem randomly switch between
>    sound cards?

The file utility is useful, and you'd invoke it in a Terminal on the
target:

e.g., $ file "207. Xanadu.mp3"
207. Xanadu.mp3: MP3 file with ID3 version 2.3.0 tag

>    - Where can I get multimedia players for Linux that work without the
>    headaches and hassles -- kind of like I've been finding under Windows since
>    Win98?  (I thought the bazaar was supposed to be more responsive and
>    flexible than the cathedral!)

The distinction between the bazaar and the cathedral is largely
irrelevant here. Underlying your multimedia troubles is in fact a sound
infrastructure issue, not a development one.
-- 
Daniel T. Chen            crimsun at ubuntu.com
GPG key:   www.sh.nu/~crimsun/pubkey.gpg.asc
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