Help using alsa & dmix?

Message

triablo · Post by **triablo** » Sat Jun 04, 2005 9:29 pm

Ok, here's the deal:

-I use alsa
-I want to be able to play more than 1 stream at a time
-I have tried esound & arts, but that was too high audio latency
-My audio chipset is a CM8738 (C-media, integrated on a MSI motherboard)

so I tried to setup this dmix thingy to make support for multiple streams, bud it didn't work out so well.

here's my .asoundrc:

Code: Select all

pcm.!default {
        type plug
        slave.pcm dmixer
}
                                                                         
pcm.dmixer {
        type dmix
        ipc_key 1024
        ipc_key_add_uid true
        slave {
                pcm "hw:0"
                period_time 0
                period_size 1024
                buffer_size 8192
                rate 44100
        }
}

what is wrong in there? and is there anything more I have to do to make it work?

and if none are able to answer:
is there any way to decrease audio latency in esound/arts, so that I could:o use them?

ty,
-- triablo

avieth · Post by **avieth** » Sat Jun 04, 2005 9:39 pm

Which sound card are you using?
This should help:
http://gentoo-wiki.com/HOWTO_ALSA_sound_mixer_aka_dmix

triablo · Post by **triablo** » Sat Jun 04, 2005 9:58 pm

avieth wrote:Which sound card are you using?

triablo wrote: -My audio chipset is a CM8738 (C-media, integrated on a MSI motherboard)

avieth wrote: This should help:
http://gentoo-wiki.com/HOWTO_ALSA_sound_mixer_aka_dmix

No, actually that doesn't help much.

avieth · Post by **avieth** » Sat Jun 04, 2005 10:08 pm

triablo wrote:
avieth wrote:Which sound card are you using?

triablo wrote: -My audio chipset is a CM8738 (C-media, integrated on a MSI motherboard)

avieth wrote: This should help:
http://gentoo-wiki.com/HOWTO_ALSA_sound_mixer_aka_dmix
No, actually that doesn't help much.

Oh sorry bout the sound card thing, just skimmed through.

That page should help you, the section on dmix contains good working examples:

Code: Select all

pcm.dsp0 {
    type plug
    slave.pcm "dmix"
}
# mixer0 can stay unchanged, because it isn't used anyway, I guess ;)
ctl.mixer0 {
    type hw
    card 0
}

This is what they have put for nforce board:

Code: Select all

pcm.nforce-hw {
        type hw
        card 0
}
pcm.!default {
        type plug
        slave.pcm "nforce"
}
pcm.nforce {
        type dmix
        ipc_key 1234
        ipc_perm 0660
        slave {
                pcm "hw:0,0"
                period_time 0
                period_size 1024
                buffer_size 4096
                #rate 44100
                rate 48000
        }
}
ctl.nforce-hw {
        type hw
        card 0
}

Looks similar to yours. If the first example doesn't work just try this one.

triablo · Post by **triablo** » Sat Jun 04, 2005 10:51 pm

I tried all the configs.
not even the the config specifieds for cm8738 worked properly.

qeed · Post by **qeed** » Sun Jun 05, 2005 1:38 am

try wrapping your applications around aoss...such as xmms, you would do "aoss xmms"

triablo · Post by **triablo** » Sun Jun 05, 2005 7:52 am

nah,
none of it f**king works!
I'll just start using esound again, if noone have a better alternative..?

gimpel · Post by **gimpel** » Sun Jun 05, 2005 10:41 am

maybe try alsa 1.0.9

since alsa 1.0.9 dmix is enabled by default for most soundcards that are not able to do hardware mixing.
AFAIK it's not enabled only for envy24 based HQ soundcards.

or check out a cheap soundblaster live, 5-10 @ ebay.... much better than a onboard cmedia

Grahammm · Post by **Grahammm** » Sun Jun 05, 2005 11:51 am

gimpel wrote:since alsa 1.0.9 dmix is enabled by default for most soundcards that are not able to do hardware mixing.
AFAIK it's not enabled only for envy24 based HQ soundcards.

It would be nice if it also worked by default with OSS emulation so that 'legacy' programs would not block each other out or fail because they think the sound device is busy.

Tsuna · Post by **Tsuna** » Sun Jun 05, 2005 12:29 pm

post your kernel config

Code: Select all

grep "^[^#]" /path/to/your/.config

gimpel · Post by **gimpel** » Sun Jun 05, 2005 12:35 pm

Grahammm wrote:
gimpel wrote:since alsa 1.0.9 dmix is enabled by default for most soundcards that are not able to do hardware mixing.
AFAIK it's not enabled only for envy24 based HQ soundcards.
It would be nice if it also worked by default with OSS emulation so that 'legacy' programs would not block each other out or fail because they think the sound device is busy.

snd-pcm-oss has an option for that, see modinfo snd-pcm-oss

http://www.sabi.co.uk/Notes/linuxSoundALSA.html#ossEmulation wrote:OSS applications dont share the sound card
By default the OSS compatibility devices respect POSIX rules and allow only exclusive opens unless the O_NONBLOCK option is given to open(2). This can be worked around either by using the aoss program, oss2jack, the non-block configuration directive, or the nonblock_open options of the snd-pcm-oss modules.

Simius · Post by **Simius** » Fri Nov 24, 2006 10:22 pm

This whole ALSA madness doesn't compute! Ever since I use an onboard soundcard, I am unable to run two ALSA based programs (like audacious and mplayer) side by side! I mean, NO, IT'S NOT A FREGGING OSS EMUL PROBLEM! TWO FREGGING ALSA PROGRAMS! And mplayer gives me this shit when a song is playing on audacious:

Code: Select all

alsa-lib: pcm_dmix.c:864:(snd_pcm_dmix_open) unable to open slave

Now, I've read all I found on ALSA. I even read that "dmix" wiki article, which is the most unintelligible piece of hogwash I've ever read. For one, where is dmix? Is it in the kernel modules, or the library? What reads ~/.asoundrc? Why can't I just place the dmix config in /etc? How on earth do I enable dmix if it isn't enabled "by default"? And for Heaven's sake, I've never ever read about two ALSA programs conflicting, everybody is going on and on about OSS. Freg OSS! What should I do to have ALSA programs playing nicely alongside ALSA programs, and using that godforsaken dmix?!

Thanks for your help, in advance!

anthrax · Post by **anthrax** » Sat Nov 25, 2006 8:42 am

/me raises his "ME TOO" hand

Dmix and Alsa need to sort themselves out I agree, I have a PCI basec CMI8738 card and dmix *still* doesnt work right. I have current gotten it to the point where if the card is in use it transfers it to the headphones which are connected to the digital out. Not good enough, but I get by until things get better, let me know if you guys make any progress.

Simius · Post by **Simius** » Sun Nov 26, 2006 7:59 pm

Well, I did get ALSA progs working together. Now only the 32 bit - 64 bit bug remains to be fixed.

I read some of the upstream docs, which I recommend to everyone suffering from the same problem. Also, for some reason, Audacious doesn't list the virtual devices one specifies in asound.conf (yep, you CAN put it in /etc) or .asoundrc, so to get dmix working, one needs to redefine Default.

anthrax · Post by **anthrax** » Tue Nov 28, 2006 6:31 pm

Do you mean the documentation on the Alsa Project website or some documentation that comes with the ebuild?

arabis · Post by **arabis** » Tue Nov 28, 2006 9:05 pm

Simius wrote:Well, I did get ALSA progs working together. Now only the 32 bit - 64 bit bug remains to be fixed

If this is a 32bits-64bits compatibility problem, see bug 148102: http://bugs.gentoo.org/show_bug.cgi?id=148102
Replace your libasound.so.2.0.0 with this one http://www.fluffypenguin.org/gentoo/libasound.so.2.0.0

Help using alsa & dmix?

Help using alsa & dmix?

dmix hell

Heh...