RFE: Pulseaudio Bluetooth FastStream audio codec support for higher quality microphone/backchannel
Add Pulseaudio support for bi-directional bluetooth audio in A2DP mode, using "FastStream" codec, which allows for higher quality backchannel/microphone compared to HFP mode.
quote/info from another (pipewire) issue pipewire/pipewire#974 (closed) : "Faststream appears to be a hack that combines a 48 kHz 212 kbps SBC audio stream with a 16 kHz 72kbps voice stream. Compare this to msBC which is 16 khZ 60.8 kbps bidirectional. Basically you are getting average quality audio with slightly higher than HFP quality voice."
For a list of devices supporting FastStream codec one can check for example: https://btcodecs.valdikss.org.ru/codec-compatibility/
Some info about FastStream codec is also available in the (not merged) pulseaudio A2DP FastStream patches: https://lists.freedesktop.org/archives/pulseaudio-discuss/2019-June/031175.html