On Wed, Apr 28, 2021 at 06:21:27PM +0000, Rodolfo Medina wrote: > Joel Roth <jo...@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?
The soundcard capabilities that linux sees are documented in the /proc/asound filesystem. That's worth investigating. Here's one reference to what you can find there: https://www.ti.com/lit/an/sprac10/sprac10.pdf Another helpful source for guidance would be the Linux Audio Users mailing list, with many knowledgeable and helpful members. cheers > Thanks, > > Rodolfo > -- Joel Roth
