[mythtv-users] SPDIF passthrough

[Seth]

> Jesse Burt wrote:
> > On Tue, 2008-02-05 at 11:14 -0500, Jason Jesso wrote:
> >> My current settings are:
> >>
> >> Audio output device: ALSA:cards.pcm.iec958
> >> Passthrough output device: ALSA:iec958:{ AES0 0x02 }
> >>
> >> - Enable AC3 to SPDIF passthrough (CHECKED)
> >> - Enable DTS to SPDIF passthrough (CHECKED)


I found the aplay -L, and -l output kind of confusing.  I finally got
it working by pulling the info from /proc/pcm/devices:

[root at mythtv ~]# cat /proc/asound/pcm
00-02: ICE1724 Surrounds : ICE1724 Surround PCM : playback 2
00-01: IEC1724 IEC958 : IEC1724 IEC958 : playback 1
00-00: ICE1724 : ICE1724 : playback 1 : capture 1
01-04: Intel ICH - IEC958 : Intel ICH5 - IEC958 : playback 1
01-03: Intel ICH - ADC2 : Intel ICH5 - ADC2 : capture 1
01-02: Intel ICH - MIC2 ADC : Intel ICH5 - MIC2 ADC : capture 1
01-01: Intel ICH - MIC ADC : Intel ICH5 - MIC ADC : capture 1
01-00: Intel ICH : Intel ICH5 : playback 1 : capture 1

The intel device is on the mobo, the ICE1724 is my M-Audio Revolutions
5.1 card.   The IEC958 entry is the coax digital out plug.   For some
reason device=hw did not work for me. I had to use "plughw" card 0,
port 1.

mplayer -ao alsa:device=plughw=0.1 -ac hwac3, test.avi, works
perfectly.   I added the -ao and -ac lines to my mplayer line in
mythvideo and it worked.



> I have the exact same problem - except mine used to work then all of a
> sudden has stopped working with no changes made to config.  Only thing I
> could think of was that something updates and broke it.
>
> Cheers,
>  Steve

Regarding the sound all of a sudden not working, it might be that the
OS has changed the Device number last time you updated alsa, rebooted,
or something like that.

Find it again with cat /proc/pcm/devices.  Last time that happened to
me, I had to change the mplayer line in mythvideo from a 1.1 to a 0.1,
and I had to change the audio mixer device in the general mythtv
settings page from adsp1 to adsp.

Hope this helps either one of you or both.  I've just finished what
probably amounted to something in the order or 10-15 hours trying to
get mythvideo, mythmusic, and mythdvd to all work perfectly with
digital out, but let me tell you... IT WAS WORTH IT. haha.


-Seth