[LAU] ALSA and RME Raydat troubleshooting

[Vaclav Mach]

Hello,
On 10/21/2014 04:11 PM, Paul Davis wrote:
>
>
> testing this configuration using aplay doesn't make any sense. you
> apparently believe that getting glitch-free audio playback is a
> trivial task ... it isn't unless you are prepared to use a lot of
> buffering (which is what happens in a lot of consumer-ish software.
I've used aplay just for an example, we have a software application
where it behaves the same way.
>
> you are also attempting to use ALSA dmix facilities, which is not
> recommended by anyone for any purpose (distributions that used to use
> this now use pulseaudio to accomplish multiplexing streams to a single
> hardware device).
>
> it is certainly possible to play streams to multiple devices at once,
> but if you expect utilities like aplay to do this correctly on an
> arbitrary system, you are mistaken. your problems could be in the ALSA
> dmix layer, or your kernel or your overall system configuration (see,
> for example, this list of problem areas:
> http://manual.ardour.org/setting-up-your-system/the-right-computer-system-for-digital-audio/)
dmixing is no problem on MB Intel HDA sound device, but I know that
there should be a difference in setting up a professional audio device
>
> you haven't really described what your application area is, but if it
> involves multiple appplications sharing an audio device and using low
> latency, then i think most people would suggest you look into JACK,
> either to use it directly or as a code model (remembering, however,
> that is is released under the GPL).
we have a bad experience with Jack: we were running jack on a computer
with external and internal sound cards simultaneously. Jack was
complaining that there is no clock sync (since there is no clock sync
possibility on internal HDA / sound blaster sound cards).

Thank you for your ideas.
Vaclav