[libcamera-devel] reporting of gain and analogue gain

[David Plowman]

Hi everyone

Whilst doing some maintenance on the Raspberry Pi AGC I noticed a bit
of an oversight - we have no way to report the total gain being
applied to an image. We have controls to report:

* the exposure time of the sensor
* the analogue gain applied in the sensor
* red and blue colour gains applied by the AWB

but nothing for any (global) digital gain demanded by the AGC. The
consequence is that when I capture a jpeg I always report an ISO value
based purely on the analogue gain which may be incorrect (when a
higher gain is required than the sensor allows then we make up the
difference with digital gain).

Any thoughts on this? Obviously there could be a digital gain control...

Best regards
David