[mythtv-users] Issues with audio over HDMI

Allen Edwards allen.p.edwards at gmail.com
Mon Jan 19 03:35:54 UTC 2009

I posted this just last week.  Either you missed it or for some reason
it isn't working for you.  However, I saw you were using alsa.conf so
that could be the problem.  Try these settings if you have not
already.  They have helped a number of people get digital sound out of


For spdif I recommend the following settings:

Audio output device: ALSA:spdif
Passthrough output device: ALSA:iec958(AESO 0x02)
max Audio Channels: Stereo  (this feature is broken so this is the
recommended setting even for 5.1)
Upmix: Passive
Enable AC3 to SPDIF passthrough (checked)
Enable ETS to SPDIF passthrough (checked)
Aggressive Sound Card Buffers (unchecked)

Remove or rename alsa.conf and .asoundrc if it exists.
If you are running Fedora, remove pulseaudio and all its files.  There
was a post that outlined the process but it is gone.  A copy is below.

Run alsamixer and enable iec958.  Use the right arrow key to see it.

Copy of someone else's post:

The steps I followed were:
-1- Rename (add "-orig") to cripple:    /etc/pulse
                                       /home/<user name>/.pulse-cookie
-2- Run   rpm -qa | grep "pulse"   and   rpm -qa | grep "pa"    to find
the stuff loaded for pulse audio.  Remove it via yum ("yum remove xxx"),
one item below per run:
This leaves:    libflashsupport
To remove these would take too many other dependencies.

IIRC, there were subsequent notes on several sites that removing only
alsa-plugins-pulseaudio was enough.  I'm not certain that "I recall
correctly" and even if I do, it might not be enough for Fedora 9.  But
I'd probably try that first to see if it (alone) works.  Besides, since
you'll eventually need to do it, there's no harm.

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