07-25-2022, 05:59 AM
For the original Megous documented the routing, and the diagrams act as a good guide if you go looking into the available controls in alsamixer.
https://xnux.eu/devices/feature/audio-pp.html
I haven't seen an equivalent for the Pro, though I haven't been looking so it may be out there somewhere. Perhaps something in Megous' development log I missed?
https://xnux.eu/log/
If it isn't you'll probably have to go into the details of the schematic and the datasheets to work out exactly what's connected to what, and compare with the mixer settings to see how the audio is being routed. It's probably using low level digital connections between processor, modem and bluetooth too, where both ends need to have the same configuration for it to work.
This hardware specificity is why at a high level Android has a number of specified standard audio profiles that the application can use. It's then up to the manufacturer to provide the correct hardware-specific settings for these profiles as part of the hardware abstraction layer. We have the beginnings of that with the alsa ucm profiles, but there are situations we don't yet have profiles for. We may not even have standard names for them. File under 'things we still need for a viable smartphone platform.'
https://xnux.eu/devices/feature/audio-pp.html
I haven't seen an equivalent for the Pro, though I haven't been looking so it may be out there somewhere. Perhaps something in Megous' development log I missed?
https://xnux.eu/log/
If it isn't you'll probably have to go into the details of the schematic and the datasheets to work out exactly what's connected to what, and compare with the mixer settings to see how the audio is being routed. It's probably using low level digital connections between processor, modem and bluetooth too, where both ends need to have the same configuration for it to work.
This hardware specificity is why at a high level Android has a number of specified standard audio profiles that the application can use. It's then up to the manufacturer to provide the correct hardware-specific settings for these profiles as part of the hardware abstraction layer. We have the beginnings of that with the alsa ucm profiles, but there are situations we don't yet have profiles for. We may not even have standard names for them. File under 'things we still need for a viable smartphone platform.'