Call recording?

[Greendrake]

First of all, let us please not be sidetracked by the question of legality of call recording. There are places in the world where recording calls is perfectly legal without telling anyone (as long as you are a party to the call), so let's just assume the feature is to be used by people from/in those places only. I am one of them.

So, is there any software that can be run on PPP to record phone calls at all?

[wibble]

I don't think there's anything that does it as standard. This is at least in part because we don't have a standard set of audio profiles to cover the different tasks so that the necessary mixer and control settings can be abstracted, so an app would end up hardware-specific. I haven't checked whether it's the same on the Pro, but on the base PinePhone the standard audio routing for calls doesn't go through the record/replay interfaces, so the app would have to change this before initiating recording. It would also need to know about routings for headset or bluetooth.

[Greendrake]

I haven't checked whether it's the same on the Pro, but on the base PinePhone the standard audio routing for calls doesn't go through the record/replay interfaces, so the app would have to change this before initiating recording. It would also need to know about routings for headset or bluetooth.

Interesting! Can you please post some links where that can be checked for Pro? Guess this info is publicly available?

I pretty much suspected that I may have to end up writing some custom apps to accomplish the task. Lack of call recording is currently the only thing that stops me from switching to Pro as the primary phone for calls (now still using an old Android in which the ability to record calls wasn't yet removed).

[wibble]

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.'