libcamerasrc / gstreamer plugin expose sensor-mode configuration

[Jeffrey Katz]

Hello list,

it was suggested on the github issue 
(https://github.com/raspberrypi/libcamera/issues/222) to bring this 
topic to the list, so I am doing so.

The usability of libcamerasrc is severely impacted by not being able to 
force a specific sensor configuration, especially on platforms like the 
Raspberry Pi 5 where there is no additional hardware support for things 
like resizing or recoloring video.

Ideally, as with exposure controls and the rest, we should be able to 
specify a sensor format in the gstreamer pipeline.

We are currently patching around this, but it seems like a fairly 
important bit of functionality to have missing.

(far more details in the linked github issue)

-jk