[mythtv-users] No HDMI audio

[Jim Stichnoth]

On Tue, Jun 23, 2009 at 2:24 AM, Jim Stichnoth<stichnot at gmail.com> wrote:
> Sorry for yet another digital audio thread.
>
> I can't get any audio whatsoever to go through my HDMI connection.
> Here are some details of my setup:
>  - Gigabyte GA-E7AUM-DS2H motherboard
>  - MythDora 10.21 (kernel 2.6.27.9-159.fc10.i686)
>  - alsa 1.0.20
>  - nvidia driver 180.51
>  - Vizio TV model VW32L
>
> The alsa version is a little weird.  "yum list alsa\*" shows version
> 1.0.20-1.fc10 of alsa-lib.i386, alsa-lib-devel.i386, and
> alsa-utils.i386, yet "cat /proc/asound/version" gives 1.0.18a.
>
> I even went so far as to disable onboard audio in the BIOS setup,
> leaving HDMI audio enabled.  Here are the results of aplay:
>
> $ aplay -l
> **** List of PLAYBACK Hardware Devices ****
> card 0: NVidia [HDA NVidia], device 3: NVIDIA HDMI [NVIDIA HDMI]
>  Subdevices: 1/1
>  Subdevice #0: subdevice #0
> $ aplay -L
> hdmi:CARD=NVidia
>    HDA NVidia, NVIDIA HDMI
>    HDMI Audio Output
> null
>    Discard all samples (playback) or generate zero samples (capture)
>
> Alsamixer shows just one control, IEC958, and I have unmuted it.
>
> No audio with Myth.  No audio with something like "mplayer -ao
> alsa:device=hdmi -afm hwac3 1071_20090620215900.mpg".  No audio with
> "speaker-test -D hdmi -c 2".  I tried following Allen's tips in
> http://www.mythtv.org/wiki?title=AllensDigitalAudioHowto (but at 2:00
> in the morning I'm not sure I tried every combination).  Pulseaudio
> appears not to be installed except for pulseaudio-libs.
>
> Interestingly, if I ctrl-alt-F2 to switch into a console window, aplay
> says there are no devices.  I wonder why is that?
>
> Any suggestions on how to proceed?  Does anyone have positive
> experience with HDMI audio on this motherboard, the Gigabyte
> GA-E7AUM-DS2H?
>
> Jim
>

Finally some closure on this: Success, and in a fairly simple way.
The short story is, don't put 'Option "UseEDID" "False" ' in your
xorg.conf file.

I was using this option, along with some others, in order to drive the
TV at its native 1366x768 resolution over HDMI/DVI.  Otherwise it
would only do 720p.

I guess that by disabling EDID, the X server and/or nvidia driver
assumed that the TV does not have any HDMI audio capability and
refused to pass the audio along.  It turns out that my other xorg.conf
options were sufficient for overriding the reported EDID resolution.
I didn't need to change my kernel or alsa module.

Everything else in Allen's how-to page was appropriate.  BTW, I really
like using ALSA's speaker-test program, which doesn't make you wonder
whether your trouble is some non-alsa misconfiguration.

Jim