Ubuntu and Multimedia (audio, in particular)

Michael Richter ttmrichter at gmail.com
Wed Jan 11 13:28:51 UTC 2006


On 11/01/06, crimsun at fungus.sh.nu <crimsun at fungus.sh.nu> wrote:
> 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.

Thanks for the help, Daniel.  I glanced into that pseudo-file before
and saw nothing out of the ordinary.  Here's what it has:

=====
0 [A5451          ]: ALI5451 - ALI 5451
                     ALI 5451 at 0x8800, irq 11
1 [MP3            ]: USB-Audio - Sound Blaster MP3+
                    Creative Labs Sound Blaster MP3+ at
usb-0000:00:0c.2-3.1, full speed
=====

> 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.

I touched nothing.  I have been burned badly enough by UNIX and
UNIX-workalikes in the past to know that you don't touch config files
except as a last, most desperate resort unless you REALLY know what
you're doing.

> $ 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).

Ah, now that's the kind of thing I needed to know from the man pages. 
Let me run the test.
...
OK, that ran out of the wrong set of speakers (big surprise!), so let
me fire up the script.
...
OK, running that script with "1" as the argument results in.... no
change.  It comes out the cruddy laptop speakers instead of the SB. 
Trying "0" now, even though the proc pseudofile says otherwise.
...
Nothing whatsoever.  No change no matter what argument I give it --
including bogus card values like 666.  Whatever that script is
supposed to do, it's not doing anything.  Let me try the GUI tool
instead.
...
(Irritatingly enough the system sounds are going to the right card as
I get the menu noises....)
OK, here's what happens.  When I use the GUI tool, the system sounds
-- menu noises, etc. -- come out of the appropriate places.  I set it
to the ALI card and they go to the ALI card.  I set it to the SB and
they go to the SB.  But the command line you gave me?  Always goes to
the laptop crap.  So somewhere here there is a disconnect in ALSA and
expected locations.

> 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.

OK, you've got it.  :-D  How do I switch the order of the cards?

>>    - 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

OK, I see an interesting difference here.  The ones that make Totem
choke are AC3-encoded.  Windows, if I lack AC3 capabilities, just
automagically puts things to stereo.  Apparently Totem won't do that. 
Can I tell it to do it or am I basically screwed?

Hang on!  I'm looking at /proc/asound.  Is changing the order of the
cards as simple as manipulating the symlinks for card0 and card1?

I just tarred the whole asound subtree.  Would it be in any way
helpful for me to just upload that here as an attachment?  It's about
1.4KB (tbz).


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