Notes for the CMEDIA CMI 8738
------------------------------

The OSS drivers support S/PDIF input and output. There are
several Mixer extensions that provide the S/PDIF I/O controls


1) Enable/Disable S/PDIF I/O. Enabling this will show a D/A valid
data light on your Digital-Analog convertor box.

/usr/lib/oss/ossmix spdif.enable ON|OFF

2) Enable S/PDIF I/O Loopback mode. If you connect an input source to
S/PDIF IN you will be able to hear audio back from S/PDIF Out.
NOTE: Recording is NOT possible if S/PDIF Loopback mode is enabled.

/usr/lib/oss/ossmix spdif.loop ON|OFF

3) Enable S/PDIF record monitor or to enable CD Digital Input:
This enables you to hear the recording input source from S/PDIF
via the analog monitor out ports.

/usr/lib/oss/ossmix spdif.imon ON|OFF

Note that if recording monitor is ON, you cannot hear playback data
via the analog outputs.

4) Eable SPDIF Recording. This controls spdif input mode. You can
toggle it on using ossmix spdif.record ON|OFF.

5) Enable S/PDIF signal inversion. This controls simply inverts the
S/PDIF signal. To check if your equipment handles signal inversion,
start the recording source connected to the S/PDIF IN. Then enable
S/PDIF Input monitoring (see above). If the sound is garbled, set
S/PDIFREV to OFF (/usr/lib/oss/ossmix spdif.polrev OFF) otherwise
set it to ON (/usr/lib/oss/ossmix spdif.polrev ON)