Thanks JJ
That works well for play in the Jabra Headset that I use, sox was already installed on the 64-bit image I use, here is the near enough final command line command that works for me:
pi@sbitx:~ $ arecord -D "plughw:CARD=sbitxdigiout,DEV=1" -f cd | sox -v 25.0 -t wav - -t wav - | aplay -D "plughw:CARD=5,DEV=0"? //lets me adjust a nice level of audio range with the headset volume control
I have renamed the loopbacks using a process I described in another post but essentially the command in my /etc/rc.local file is:
modprobe snd-aloop enable=1,1,1,1 index=1,2,3,4 id=sbitxdigiout,sbitxdigiin,sbitxusbout,sbitxusbin
The names are a bit long and might be shortened but just needed something I could relate to easily to begin with
Now I know the playback side of things work from the command line to a USB headset, want to incorporate into the app now so its a bit more automatic, yes it could probably be done by a startup script for the app perhaps and that might be the easiest approach but I prefer it to be within the app if possible. Audio out is better in the headset and not as coarse as it is from the speaker
Thanks again
Paul G0KAO