[mythtv-users] Digital audio: centre channel drops out intermittently

[Jean-Yves Avenard]

On 15 January 2012 15:08, Marc Sherman <msherman at projectile.ca> wrote:
> Sorry, I meant 2->5 up mixing -- the centre channel is actually active in
> this mode (presumably being sent the common signal from the L and R input
> channels).

You can't do upmixing 2->5 outside of myth (say using ALSA custom config).
If that's what you are hoping to achieve it will never work as spdif
is stereo maximum, everything more must be compressed into a digital
stream

> Are you sure? I thought that in 0.24, myth actually decodes, processes, and
> re-encodes the AC3 stream? For example, mythtv's internal volume controls
> (if enabled with the software mixer) do affect AC3 audio, and AC3 audio is
> sped up or slowed down to sync with Time Stretched playback.

you wrote in the previous post that upmixing was disabled in your myth
config. I can only go by the information you provide.


>
> Well, if myth is decoding/processing/reencoding the AC3 stream as I
> suggested above, then it could be dropping one of the channels in this code
> path.
>

You obviously have a clear idea of what is happening, so I'll leave you to it