Hi,
I am working on a camera project with the Raspberry pi compute module 4 and we are using the ADV7280-m as the video decoder. We display the camera image in our Qt application and I run these v4l2 commands to set the ADV settings after Linux bootup:
v4l2-ctl --set-standard 255
v4l2-ctl -c brightness=-128
v4l2-ctl -c contrast=100
v4l2-ctl -c saturation=128
v4l2-ctl -c hue=0
We found that sometimes after our application starts up, at first, we have a nice image with acceptable brightness and contrast, but then the AGC dims the image as though it detects too much light. This happens randomly, meaning that if we disconnect and reconnect the analog input several times, we see this dark image most of the time, but sometimes, we get a better image. Increasing the brightness with v4l2-ctl manually fixes this issue, but we would like to prevent this from happening. The corresponding images called Dark_image.jpeg and Better_image.jpeg are uploaded. Please ignore the transparent horizontal rectangles at top and bottom as they are part of our Qt application.
Kind regards,
Enayat
