[libcamera-devel] Camera mode selection

[David Plowman]

Hi everyone

I was wondering if I might return to the topic of camera mode
selection. (Apologies if this might turn into another long
meta-discussion!)

We already know that there are questions as to how and when you might
trade off things like better resolution versus higher framerates, and
it's not clear how an application might signal what it wants.

Another case I've found myself faced with recently is how to select
camera modes jointly, such as when doing preview and then capture.
Typically the preview will ask for a smaller resolution, and capture a
larger one. You might adjust the preview to have the same aspect ratio
as the capture. But so far as I understand it, it's difficult to
guarantee that the preview mode will have the same field of view as
the capture.

Do others see this as a problem, and if so how might one fix it? Have
more in the way of flags that "hint" at what the application wants?
Perhaps pass in a second resolution with the rule that the mode
selected for the first resolution must have the save FoV as the
second?

I often find myself coming back to the idea of selecting modes
explicitly - applications frequently know what sensor they're dealing
with, and probably know exactly which modes they want too.

Anyway, I'd be interested to hear people's thoughts on this one!

Thanks and best regards
David