Re: [Alsa-user] Parallel playback on multiple USB cards

2020-09-08 Thread Alexandre Bouillot
Hi Clemens,

Thanks for the hint. On a standard PC all goes well. I have 3 streams
playing and 3 recordings at the same time.

Regards,
Alexandre



Le ven. 14 août 2020 à 12:56, Clemens Ladisch via Alsa-user <
alsa-user@lists.sourceforge.net> a écrit :

> Alexandre Bouillot wrote:
> > ... Raspberry Pi
> >
> > I'm able to address each of the 6 cards independently correctly.
> > However, when I'm trying to have a second channel - not to mention the
> third - working in parallel with the first, I face problems.
>
> From what I've heard, the Pi's USB controller has limited bandwidth, and
> its
> driver is not able to distribute all of it among multiple streams.
>
>
> Regards,
> Clemens
>
>
> ___
> Alsa-user mailing list
> Alsa-user@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/alsa-user
>
___
Alsa-user mailing list
Alsa-user@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/alsa-user


Re: [Alsa-user] Parallel playback on multiple USB cards

2020-08-14 Thread Clemens Ladisch via Alsa-user
Alexandre Bouillot wrote:
> ... Raspberry Pi
>
> I'm able to address each of the 6 cards independently correctly.
> However, when I'm trying to have a second channel - not to mention the third 
> - working in parallel with the first, I face problems.

>From what I've heard, the Pi's USB controller has limited bandwidth, and its
driver is not able to distribute all of it among multiple streams.


Regards,
Clemens


___
Alsa-user mailing list
Alsa-user@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/alsa-user


[Alsa-user] Parallel playback on multiple USB cards

2020-08-14 Thread Alexandre Bouillot
Hi,

I'm trying to set up a system for audio measurements and I'm trying to have
a 3 channels solution using one single host (currently a Raspberry Pi,
might migrate to x86 later on if needed).

I have the one channel system working with two USB audio cards - one for
emitting the sound and the other to record the audio output.

I'm using shell commands as aplay and arecord.

I'm able to address each of the 6 cards independently correctly.

However, when I'm trying to have a second channel - not to mention the
third - working in parallel with the first, I face problems.

I launch aplay instances in asynchronous mode with an & at the end of the
command line.
As soon as the second instance is running, there is no more sound issued on
any boards.
As soon as there is only one instance left running, the assigned card is
properly emitting the sound.

I'm wondering if it is possible to have parallel instances of aplay, each
controlling one audio card.

Not to spoil anything, the next step will be the same, but with arecord.

Thanks for any pointers you can provide.
Alexandre
___
Alsa-user mailing list
Alsa-user@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/alsa-user