I want to get two mplayer streams (or a stream and a local file) - each already converted to mono L or R or single channel - into the onboard default pwm sound device using mixing, piping, permission forcing, whatever. Goal being to get the 3.5mm jack to output two separate single channel (zone) audio outputs. Music or voice, alt languages etc. They do need to be able to happen simultaneously, as both may be used, but no sync between the two is necessary.
So far the nemesis is that the aduio device is only available to the first source that asks to use it. I can, and do, in another application, output one stream to default, and one to usb/dac, but have a specific need to grab two streams out of (only) the 3.5mm for this one. I'm a headless pi-type guy, all species, have most of my routines banked for debian/raspbian with audio mostly being alsa / mplayer / mpg321 handled with php-cli, shell, or python. An alsa utility solution would be great but I've not been able to conceptualize and syntax one yet.
I was appropriately accused of being overly verbose the other time I asked a question here, so let me leave it at this and respond, rather than type out the whole novel here. (things have been tried, searches have been made, more complex and resource intensive methods have been conceptualized but put on hold unless necessary).
