[alsa-devel] multistream singlechanel DACs

powierski at mediascore.de powierski at mediascore.de
Fri Aug 24 16:07:37 CEST 2012

Thank you for your help Raymond.

the alsa-info.sh output is
and attached.
bios table (also attached): I tried separate associations, also association 0Fh,
always sequence 0.
both worked for win7. However it was important to have different device_type -
otherwise the outputs are only visible but not quite operational.

documentation say "all dac support independent 16/20/24-bit,
44.1k/48k/96k/192kHz sample rate",
actually it would be perfect to have 4+2 DACs if I can route it to my-defined
outputs. Also 2+2 is good, I need another 2 as a mixer out - analog
pass-through- this would be configured later by application.

as you write, this was seen working in another hardware -
obviously my problem can be solved by proper configuration - question is only
how deep I have to dive.

for now I will try to find out what is "alt_analog_playback" - maybe then i can
do configuration/routing by sending verbs to pin and mixer widgets.



Raymond Yau <superquad.vortex2 at gmail.com> hat am 24. August 2012 um 03:55

> 2012-8-24 上午1:10 於 "Rafal Powierski" <powierski at mediascore.de> 寫道:
> >
> > Developers,
> >
> > how to enable multiple playback streaming?:
> >
> > I am manipulating bios verb pin table, for special analog hardware, using
> ALC886 and kubuntu / 64bit.
> can you post the output of alsa-info.sh ?
> >
> > I need a number of separate stereo (only stereo) i/o's
> > I have correctly configured inputs:
> > 4. single stereo adc port-C 1Ah
> > 5. single spdif input 1Fh
> > I have configured 3 independent stereo outputs, but ALSA is joining them
> into one pcmC1D0p device.
> > 1.port-A,15h
> > 2.port-E,1Bh
> > 3.port-D,14h
> how do you configure them as non multi channel pin complex ? different
> association and zero sequence instead of same assosication and asscending
> sequence for multi channel pin complex with color jacks.
> > I have tried this on win7 and I got all associations as a separate
> devices.
> > in my kubuntu 12.4LTS I have only one playback device.
> this is the multi channel out device with headphone using front channel
> the major problem is pulseaudio does not support multi- streaming
> the headphone playback volume control is the slave of virtual master
> playback volume control.
> > Mixer is showing even more then needed number of volume controls,
> > But there is only one playback device.
> > it seams, all 3 outputs are connected to single DAC.
> > I have tried to buildup more input devices - this is working good.
> > I can have up to 3 (pcmC1D0c, pcmC1D1c pcmC1D2c)
> it is possible to use two or more ADCs for multi  channels capture similar
> to the multi channels playback by assign same stream tag and  channel tag
> to the three ADCs
> > I can also have 2 outputs if I enable spdif-out.
> the alc888s-vc seem has two independent digital output for spdif and hdmi
> > But there is no separate DAC assignment  to separate devices resulting
> from
> > my  config.
> >
> > Is it possible to get independent DACs devices under ALSA?
> you can use alt_analog_playback stream for independent headphone port-A
> similar to those VIA codecs
> the datasheet only mention 7.1 + 2 multi streaming using front and rear
> audio panel
> if it really work on other operating system, you may try to increase the
> number of substreams of the alt_analog_playback and assign DACs to each
> alt_analog_playback  substreams similar to the way which the driver assign
> ADCs to the capture substreams
> however you need to disable the multi channel analog  playback stream
> > or else is no such configuration possible and I have to use single
> multiple channel device?
> >
> the alternative is to use jackd
> _______________________________________________
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