[mythtv-users] multiple selectable audio device configurations

[Alistair Grant]

On Mon, Oct 27, 2014 at 12:14 AM, Brian J. Murrell
<brian at interlinx.bc.ca> wrote:
> On Sun, 2014-10-26 at 20:47 +1100, Alistair Grant wrote:
>>
>> I don't have a direct answer, but my workaround is to direct audio to
>> both HDMI and the analogue output.
>
> Ahhh.  Interesting.
>
>> I then just switch on the
>> headphones and turn down the TV volume when I don't want to make any
>> noise.
>
> Indeed.
>
>> Append the following to /etc/pulse/default.pa:
>
> Hrm.  I thought PA was frowned-upon in Myth systems.  It does seem like
> extra overhead both in terms of software footprint, but also in adding
> latency to the audio.  When it's just audio, who cares, but when it has
> to sync to video, latency matters.
>
> I think ALSA can do this kind of output combining on its own can't it?
>
> But ultimately I want full AC3 passthrough on HDMI but only 2-channel
> analog (I suppose downmixed if the source is >2 channels) on the
> headphones.  I wonder if ALSA is up to that.  :-)  Seems to be lots of
> useful information out there on outputting to multiple devices and
> downmixing 5.1 to 2.0.  Hopefully I can combine those into what I'm
> looking for.

>From what I was able to find ALSA should be able to do simultaneous
output, I just couldn't get it to work, and since I had a working
solution with pulseaudio I stopped looking.  If you're able to find
the magic incantation, please let me know.

Thanks,
Alistair