Enable digital surround/pass-through when available for appropriate encodings

[quequotion]

This is in part a feature request. Audience is downmixing DTS (5.1 AC3) to stereo.

There are a number of ways to go about this, but I think it's important to stick to the elementary style: minimize user configuration, make interaction clear and simple.

On the interface side, a single checkbox "[x] Digital Surround Passthrough" (even if only in dconf).
Internally, only pay attention to this switch when gstreamer finds digital surround encoded audio (DTS, etc)

Assuming that Gstreamer itself has passthrough capability...?

[quequotion (quequotion)]

Progress on this issue:

I was able to get AC3 output from pulseaudio working again, and observed a video with surround audio creating a 5.1 channel audio stream from audience.

It seems audience does not directly support SPDIF, but that it can output a number of channels appropriate to the available outputs.

When the stream is not encoded for surround, ie plain stereo, the output is a stereo stream that gets stretched around 5.1 speakers by pulseaudio. Haven't run any tests with mono audio streams.

This gave me two ideas:
A. Audience could learn from pulseaudio that surround-encoded streams are for passing through and not rendering as stereo.
B. Audience isn't resposible for pulseaudio not including a 5.1 digital surround driver by default, but then who is....

[quequotion (quequotion)]

I was able to get this working after doing considerable hacking in /etc/asound.conf

The problem is not with Audience.