[LAU] Zita-ajbridge ?

[Marc Lavallée]

Hi again Fons.

Fons Adriaensen <fons at linuxaudio.org> a écrit :
> > jackd -r -d alsa -d hw:2 -P -o 8 -z shaped
> 
> Why do you use -r ? Does your system not allow real-time ?

Oops. I use a generic 3.7 kernel that allow real-time, so -r is bad.
The correct switch is -R (default).

> Why -o 8 ? Even if you have 8 outputs that is not necessary.

Oops again; all channels are available without -o 8.

> There is no need to resample anything.

Right... This is your use case for zita-resampler:
"The development of zita-resampler was triggered by the need to
resample multichannel files (HOA, 25-ish channels), while still keeping
some CPU capacity for other tasks."
So I don't need it. Less is more! :)

> Does hw:1 work with Jack ?

Yes.

> Did you connect anything to the zita-j2a ports ?

Yes.

> As said, unless you have some voodoo SW on your machine, that is not
> possible. If mplayer uses jack, it doesn not know anything about the
> sound card. Not the sample format, not the number of channels, only
> the sample frequency.

So Mplayer is just reporting the output frequency of Jack?

> > Another problem: when starting Jack with a 2 channels sound card,
> > Mplayer can't output more than 2 channels. 
> 
> Again, mplayer can't know this. Your are probably running on
> some other soundcard, not using Jack.

I confirm: when using Jack with the internal soundcard (with 2 output
channels), Mplayer limit its number of output channels to 2, even if I
specify the number of channels of my sound file (4) to Mplayer.

Update: 
- I installed the latest Jackd (version 1.9.10 from Grame): zita-j2a now works! :) 
  after the "Starting synchronisation" message, there's now a
  continuous sequence of numbers. Suggestion: a note in the
  documentation about the version of Jackd would help.
- I installed the latest Mplayer (2): same behaviour...

Thanks for you help.

N.B. The descriptions in the man pages are inverted:
zita-j2a - Use ALSA capture device as a Jack client, with resampling.
zita-a2j - Use ALSA playback device as a Jack client, with resampling.

--
Marc