[mythtv-users] All TV plays back as stereo and not surround over HDMI

[Jean-Yves Avenard]

On 14 January 2013 11:29, Brendon Costa <brendon.j.costa at gmail.com> wrote:
> From what I have read, this is a common issue with ALSA on some devices. The
> channel mapping is correct for other devices (from example the Blue-ray
> player connected to the same receiver).

The only device that I know of that is incorrect HDMI channel mapping
is the old nvidia 9400M

It's an issue with the hardware card, not alsa.

> I will have to check when I get home but I don't believe I am running any
> transcode job right now. I disabled the transcode and ad-search recently for
> other reasons.
>
> Is there anything else in the backend settings that may cause it to only
> record in stereo?
no... the backend records the data as it is being received. It doesn't
trim or convert or anything like that unless you run a transcode job
on it.

if it recorded stereo, and you don't have transcoding job running: the
original signal was stereo. period

>
> I just did some more reading, and it may be that Australian TV broadcast
> rarely transmits in surround. I will try and see if I can test a few more
> recordings tonight.

it depends on the TV station
Gem, OneHD, ABC24 are 5.1

The others are mp2 (stereo)

>
> I am still not sure about the best option for configuration of the frontend
> 5.1? Do i still need to set to stereo to get the passthrough to work?

only if your device supports DTS or AC3.
5.1 AC3 will be passed through then...

With HDMI it doesn't really matter, either myth will decode it, or your amp will

If you're connected to your TV via HDMI, set audio as stereo, uncheck
AC3 and DTS
if it's connected to an amplifier, set it as 5.1 or 7.1, check AC3 and
DTS, and check the others if your amp supports the codec.

JY