digiface vs. multiface vs. jack vs. other cards

digiface vs. multiface vs. jack vs. other cards

[Fernando Lopez-Lezcano]

At CCRMA we have several studios with linux computers in them (in
addition to computers sprinkled throughout the building). Some of the
studios have digiface interfaces, some multiface. All of them are
connected to the sound system or mixer digitally through adat
lightpipes. Workstations have Delta 66 or Gina3G soundcards. 

It would be nice for a user to be able to play, say, a stereo Ardour
session in any of them without any changes to the session or routing. 

The digifaces send channels 1-24 out the adat ports. The multifaces on
the other hand send 9-16 on the adat port. Deltas and Ginas send out
stuff on channels 1-4 or 1-6. 

You can see the multiface interfaces are a problem. To get sound out of
them you have to send on channels 9-16 which is different from _all_
others! 

I tried several workarounds without much success:

a) fix this at the alsa level. Should be the way to go, right? Create
an /etc/asound.conf that uses ttable to translate channels for the
multifaces so that the digital out is actually sent through channels 1-8
(and create the same name plug interface in all other computers that
does nothing so that the user can set that name as the default in
qjackctl and will get the same behavior in all computers). 

Works, but not quite. When I try to use that "fake" plug interface with
jack2 I get a warning that I'm using a plug interface (sort of fair) and
jack only opens it with _2_ i/o channels (even though the ttable is 18
channels wide!). If I _force_ input and output channels in jack to 18 it
does work fine. But now it will _not_ work on other computers that have
less (or more) than 18 channels. Argh. 

b) fix it in hdspmixer. Well, it turns out that hdspmixer does not read
the default matrix gains from a file so I can't really override the
default. AFAICT the gains are calculated algorithmically in the code and
there is no command line option to load presets from a file. 

Or I could write a small script that will set the right gains for 1-8 to
go out through 9-16 but if a user starts hdspmixer that gets undone with
no warning. 

And, of course:

c) give up and connect an 8 channel analog snake to the analog outputs
of the multifaces and do away with a digital connection to the mixer...

Anyone has any other suggestions??
This should be easy to fix, right?
:-)
-- Fernando

Re: [LAD] digiface vs. multiface vs. jack vs. other cards

[Frank Smith]

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Hi Fernando
Can't help you on the coding but if you find a way to link two RME PCI hdsp
cards to show as one please pass this along.

I have two cards that I have to constantly change as the Bois seems to
change the order of the cards on Boot up ( I use jack to select the cards)


Cheers
Bob
Blueslsd



On 29 March 2010 18:49, Fernando Lopez-Lezcano <nando-l0SEpsmuUtBegcJQxxnBRDe48wsgrGvP@public.gmane.org>wrote:

> At CCRMA we have several studios with linux computers in them (in
> addition to computers sprinkled throughout the building). Some of the
> studios have digiface interfaces, some multiface. All of them are
> connected to the sound system or mixer digitally through adat
> lightpipes. Workstations have Delta 66 or Gina3G soundcards.
>
> It would be nice for a user to be able to play, say, a stereo Ardour
> session in any of them without any changes to the session or routing.
>
> The digifaces send channels 1-24 out the adat ports. The multifaces on
> the other hand send 9-16 on the adat port. Deltas and Ginas send out
> stuff on channels 1-4 or 1-6.
>
> You can see the multiface interfaces are a problem. To get sound out of
> them you have to send on channels 9-16 which is different from _all_
> others!
>
> I tried several workarounds without much success:
>
> a) fix this at the alsa level. Should be the way to go, right? Create
> an /etc/asound.conf that uses ttable to translate channels for the
> multifaces so that the digital out is actually sent through channels 1-8
> (and create the same name plug interface in all other computers that
> does nothing so that the user can set that name as the default in
> qjackctl and will get the same behavior in all computers).
>
> Works, but not quite. When I try to use that "fake" plug interface with
> jack2 I get a warning that I'm using a plug interface (sort of fair) and
> jack only opens it with _2_ i/o channels (even though the ttable is 18
> channels wide!). If I _force_ input and output channels in jack to 18 it
> does work fine. But now it will _not_ work on other computers that have
> less (or more) than 18 channels. Argh.
>
> b) fix it in hdspmixer. Well, it turns out that hdspmixer does not read
> the default matrix gains from a file so I can't really override the
> default. AFAICT the gains are calculated algorithmically in the code and
> there is no command line option to load presets from a file.
>
> Or I could write a small script that will set the right gains for 1-8 to
> go out through 9-16 but if a user starts hdspmixer that gets undone with
> no warning.
>
> And, of course:
>
> c) give up and connect an 8 channel analog snake to the analog outputs
> of the multifaces and do away with a digital connection to the mixer...
>
> Anyone has any other suggestions??
> This should be easy to fix, right?
> :-)
> -- Fernando
>
>
> _______________________________________________
> Linux-audio-dev mailing list
> Linux-audio-dev-cunTk1MwBs/CEJeg2xFRV2D2FQJk+8+b@public.gmane.org
> http://lists.linuxaudio.org/listinfo/linux-audio-dev
>

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