Audio: Full Duplex Playback/Record
I'm trying to do full duplex audio recording using Audacity. This involves listening to a previously recorded audio track while recording a new one. The program is configured to use /dev/dsp for both record and playback but I've gotten the impression from googleing that I need to use /dev/dsp for recording and /dev/dsp1 for playback. (Seems to make sense...)
When I try to do this in Audacity using the stock setup, it does indeed record a new track but the new audio track is very distorted (garbled) sounding.
I see both dsp and dsp1 device files in /dev but Audacity only lists /dev/dsp in it's dropdown menu of which device to use.
My sound hardware is built-in: Intel 82801DB-ICH4 which I'm pretty sure is capable of full duplex operation. Does anyone know if this is true and, if so, then what is missing on the software/os side?
How do I make use of both dsp and dsp1 devices?
BTW, I'm using the ALSA drivers, etc from "Planet CCRMA".
Thanks in advance,