Re: Multichannel audio playback

[Rodolfo Medina <rodolfo.medina@gmail.com>]

Joel Roth <joelz@pobox.com> writes:

> I don't think there is a problem with ecasound. 
> For comparison, you can try
>
> aplay -D <devicename> test.wav
>
> You get the device name from aplay -L.
> Please also show the output from 
>
> cat /proc/asound/cards
>
> With your ecasound examples, the -a argument is not necessary, and
> selecting channels is not its purpose.


Now it works: 


$ ecasound -a:1,2,3 -i:sndfile,3canali.wav -o alsaplugin,2,0
**************************************************************************
*        ecasound v2.9.1 (C) 1997-2014 Kai Vehmanen and others    
**************************************************************************
(eca-chainsetup) Chainsetup "untitled-chainsetup"
(eca-chainsetup) NOTE: Real-time configuration, but insufficient privileges
... to utilize real-time scheduling (SCHED_FIFO). With small buffersizes,
... this may cause audible glitches during processing.
(eca-chainsetup) "rt" buffering mode selected.
(audioio_sndfile) Using libsndfile to open file "3canali.wav" for reading.
(eca-chainsetup) NOTE: using existing audio parameters -f:s16_le,3,48000
... for object 'sndfile' (tried to open with -f:s16_le,2,44100).
(eca-chainsetup) Opened input "sndfile", mode "read". Format: s16_le,
... channels 3, srate 48000, interleaved (locked params).
(eca-chainsetup) Opened output "alsaplugin", mode "write". Format: s16_le,
... channels 2, srate 48000, interleaved.
- [ Connected chainsetup: "untitled-chainsetup" ] ------------------------
- [ Controller/Starting batch processing ] -------------------------------
- [ Engine - Driver start ] ----------------------------------------------

- [ Engine - Processing finished ] ---------------------------------------
- [ Controller/Batch processing finished (0) ] ---------------------------
- [ Controller/Processing stopped (cond) ] -------------------------------
- [ Engine exiting ] -----------------------------------------------------
(eca-control-objects) Disconnecting chainsetup:  "untitled-chainsetup".


So we could consider problem 1) solved.

Let's try to go to problem 2).  The above command properly sends channel 1 to
loudspeaker 1 and channel 2 to loudspeaker 2, but it doesn't manage to send
channel 3 into loudspeaker 3.  Actually, the Behringer seems to behave in
stereo mode.  But the strange thing is that outputs `B' (i.e. 3 and 4) do not
work at all and seems to be dead.  So please help: how can I - if ever possible
- send channel 3 to loudspeaker 3?  And, more in general: is it possible, even
with some other device, to achive what I want?

Thanks,

Rodolfo