[mythtv-users] Turtle Beach Riviera /CMedia CMI8738 and optical SPDIF

Peter pete at putzin.net
Mon Jan 29 20:34:32 UTC 2007

Has anyone been able to get a Turtle Beach Riviera working on their system
so that a 5.1 stream will go out of the optical connection?  (I have read
here and there that Cmedia has advertised that it works, but it really
I can get 2 channels go do through, but no 5.1.  I am grinding through the
email thread on this list about ac3 passthrough but no luck yet.  The
following gives me 2 channels out of myth:

Myth .20 config

> > Audio output device: ALSA:iec958
> > Passthrough output device:  
> > ALSA:iec958:CARD=0,AES0=0x6,AES1=0x82,AES2=0x0,AES3=0x2

The following gives me two channels off of a DVD:

	mplayer -v -ao alsa:device=iec958 dvd://

The following gives me no sound off of a DVD:

	mplayer -v -ao alsa:device=iec958 -afm hwac3 dvd://



Clay, I'm following up using a new thread. I have the same problem with FC6 and anything using AC3 (myth, mplayer, etc). Neither HD content, nor any digital track will play. Non digital sound plays, but here's the kicker, it's jittery. MP3 playback is jittery and the level changes slightly up and down. SD TV playback is just choppy. All of this is through the spdif connection, all with the ALSA:spdif designation. ALSA:dmix doesn't work, and ALSA:default behaves the same as spdif. These are all options listed using aplay -L.

What I'm thinking is I don't have the correct options set in the ALSA mixer. I know there is sound, just not sure how to get it out. I have the following IEC958 options available.

IEC958 5v
IEC958 Copyright
IEC958 In Monitor
IEC958 In Phase Inverse
IEC958 In Select
IEC958 In Valid
IEC958 Loop
IEC958 Output

All are muted except output, which is when analog audio sources start to work. But I don't know what to turn on to get digital to start working. I've been experimenting all day with different sets of values to no avail.


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