Last week an update arrived in PureOS with improvements for #Librem5 call audio. You should be more legible to your interlocutors during calls; also, the phone now automatically switches to external wired microphone once connected. The whole audio path went through a big overhaul, allowing for hardware volume control with zero-cross and reducing unnecessary amplification that could cause distortions.
Haven't seen people complaining about the changes so far - that's a good sign :)
@dos Do you have any insights in the #ALSA #UCM files on how to improve them? I think some technical notes would really help the #LinuxMobile community :)
@dylanvanassche Hmm, not much that would apply between various devices I'm afraid. I simply spent a lot of time with wm8962 datasheet creating mental image of every single path that's there and how can it be used. In the end it turned out that the patchwork of the UCM that we had there before did some rather questionable things, and that the codec has some handy features I wasn't aware of before :)
@dylanvanassche Hah, that page sure would have been handy before! 🤣 L5 UCM is relatively simple though, and I think you have pretty much described everything I know about UCM there already:) Checking the source code was often helpful, like https://github.com/alsa-project/alsa-lib/blob/master/include/use-case.h#L288 - but a lot of cross-checking with PulseAudio was needed too since not everything is implemented there... (no idea how PipeWire fares in that regard)
@dos Hahahah :P Yeah PulseAudio != PipeWire, I am curious how hard things will break when @postmarketOS switches ...
@dos Ah okay :) I thought you would have found some general ideas :P But still, any insights, even device specific, are great as the docs for UCM are lacking and not well understood by the community (yet). I spent already weeks on these configs for a device, but I had to generate a lot of the docs myself at pmOS: https://wiki.postmarketos.org/wiki/Alsa_UCM