Re: [LAD] USB audio on RPi3B+

2018-07-27 Thread Jörn Nettingsmeier

On 07/07/2018 05:47 PM, Fons Adriaensen wrote:

Hello all,

Has anyone tried using multichannel USB audio on a Raspberry 3B+ ?

It seems to work perfectly (using zita-alsa-pcmi) with stereo cards.

When I try my RME Babyface (12 in, 12 out) in CC mode, the device
opens without problems, but then Alsa_pcmi::pcm_wait() times out
waiting for the poll fd to become ready. Timeout in pcm_wait() is
1000 milliseconds.

The same seems to happen with Jackd, which uses similar code.

Is there anything in the Pi's system or configuration that
excludes multichannel cards ?


Not that I'm aware of. I've used an older Pi2 with a Gigaport HD+ USB 
device (eight RCA outputs at 44k1) with usable results for 5.1, and my 
KODI-based media center plays 5.1 movie content over (albeit over HDMI) 
flawlessly without breaking a sweat, ever.


If your quality requirements are modest you might want to look at the 
AudioInjector Octo I²S sound card for the Pi. I have two from an early 
series with known manufacturing defects, but if the developer (a very 
open-sourcey hardware hacker guy that is generally very helpful) has 
managed to get his chinese manufacturer to ramp up the quality control, 
it might be an option.

I did a few measurements with this card a while ago:
http://forum.audioinjector.net/viewtopic.php?t=3090

I have never used a professional USB multichannel card on the Pi since I 
don't own one (still stuck with aging ExpressCard Multi- and MADIfaces). 
But I'm trying to borrow one for testing becaus I have a similar usecase 
in the near future...



All best,

Jörn


--
Jörn Nettingsmeier
Tuinbouwstraat 180, 1097 ZB Amsterdam, Nederland
Tel. +49 177 7937487

Meister für Veranstaltungstechnik (Bühne/Studio), Tonmeister VDT
http://stackingdwarves.net
___
Linux-audio-dev mailing list
Linux-audio-dev@lists.linuxaudio.org
https://lists.linuxaudio.org/listinfo/linux-audio-dev


Re: [LAD] USB audio on RPi3B+

2018-07-07 Thread Christopher Obbard
Hi Fons,

Are you using a RT kernel at all?
Onboard i2s soundcards sound like a better option for multichannel, alas
the RPi only does 2 channels... unless you do some voodoo like transmitting
256 bits over two channels with a hardware divider... similar to how a
certain multichannel card does it ;-)



Cheers!

Chris Obbard
64 Studio Ltd

On Sat, 7 Jul 2018 at 16:48, Fons Adriaensen  wrote:

> Hello all,
>
> Has anyone tried using multichannel USB audio on a Raspberry 3B+ ?
>
> It seems to work perfectly (using zita-alsa-pcmi) with stereo cards.
>
> When I try my RME Babyface (12 in, 12 out) in CC mode, the device
> opens without problems, but then Alsa_pcmi::pcm_wait() times out
> waiting for the poll fd to become ready. Timeout in pcm_wait() is
> 1000 milliseconds.
>
> The same seems to happen with Jackd, which uses similar code.
>
> Is there anything in the Pi's system or configuration that
> excludes multichannel cards ?
>
> Ciao,
>
> --
> FA
>
> ___
> Linux-audio-dev mailing list
> Linux-audio-dev@lists.linuxaudio.org
> https://lists.linuxaudio.org/listinfo/linux-audio-dev
>
___
Linux-audio-dev mailing list
Linux-audio-dev@lists.linuxaudio.org
https://lists.linuxaudio.org/listinfo/linux-audio-dev