[mythtv-users] HDMI and audio

[Patrick Doyle]

On Wed, Nov 18, 2009 at 5:27 PM, Andy Colson <andy at squeakycode.net> wrote:
> What version of alsa are you running?
>
> cat /proc/asound/version
>
>
> and what does this show:
>
> aplay -L
>
At this point, I'm not running any version of alsa, as I have not
built the box yet.  I'm still in the information gathering stage,
trying to be as careful as possible to choose hardware that will work
with my TV.  Today's panic attack was brought about by a thread I read
a few days ago (see
http://www.gossamer-threads.com/lists/mythtv/users/406672) in which a
user was having difficulties getting HDMI audio to work with his Vizio
TV.   (Gee, I've got a Vizio TV as well.)

One of the responders to that message suggested that the poster "get
the jumper and jump the digital audio from the MB to the Video card".
So I downloaded the manual for the motherboard I plan to buy and
started searching for an S/PDIF jumper for the audio.  I couldn't find
one.

This was coupled with the first item that my buddy Google found when I
asked about "linux hdmi audio".  At the top of the list was an item
that claims "Audio over HDMI is not currently supported on Linux.
...".  Of course, that was from a message posted in September of 2007.

Once I got off the train (on which I was riding when I sent out my
previous message) and started driving home, it dawned on me that video
cards with HDMI outputs must present some sort of audio driver to the
kernel and that software should be able to take advantage of that
driver in order to feed audio to the device at the other end of the
HDMI link.  It also occurred to me that this might be a recent (post
September 2007) development.


> on my system I eventually have lines that say:
>
> HDA NVidia, NVIDIA HDMI
> HDMI Audio Output
>
That's consistent with my intuition, that your nVidia card registers
an audio device driver with alsa.

> I think this will tell you if you can use the ATI Radeon.  I'm not sure
> about buying a separate card.
>

I think I read a thread somewhere about audio working with an older
version of the nVidia drivers, but not with the newer one.  I can't
recall the details right now, but the bit that stands out to me is
that the nVidia drivers support audio.  That's good.  Now all I need
to do is to figure out if the driver for the ATI Radeon 3200 supports
audio.  Then I can put this issue to bed and order my hardware (quick,
before I think of something else!)

--wpd