Add alsa plugin profiles for HDMI/AC3
Description of Problem:
Pipewire alsa plugin does not support AC3 over HDMI. It does with DTS. However the AC3 alsa plugin (a52) is more supported in distributions and some devices only support AC3, including many HDMI audio extractors.
Steps to Reproduce:
- Output to an HDMI audio extractor connected to an amplifier decoding AC3.
- No option to output AC3 overs HDMI.
Actual Results:
HDMI stereo downmixes to stereo. HDMI surround drops centre, LFE, and RL/RR
Expected Results:
Option to output AC3 over HDMI.
Additional Info:
I guess that adding the following to spa/plugins/alsa/mixer/profile-sets/default.conf
would fix the problem:
[Mapping hdmi-ac3-surround]
description = Digital Surround 5.1 (HDMI 1/AC3)
device-strings = plug:{SLAVE="a52:%f,'hw:%f,0'"}
paths-output = hdmi-output-0
channel-map = front-left,front-right,rear-left,rear-right,front-center,lfe
priority = 6
direction = output
and corresponding entries for -extraN
mappings.
It would be great if those AC3 profiles could be integrated in the default profiles.
Thanks.
(same as old pulseaudio/pulseaudio#1327 )