RPi Camera, options cannot be set

[HGSvienna]

I've noticed strange behavior with LCCV and OpenCV and the Raspberry Pi's HQ Camera or GS Camera.
I'm having problems manually setting ExposureTime, Gain, and Shutter. I use C++.
About two months ago, everything worked fine; I was using OpenCV 4.10 with LCCV.
With lccv::PiCamera cam;
cam.options->ev = Exposure; // some value
cam.options->gain = Gain;
cam.options->shutter = Shutter;
I was able to set everything individually, without the automatic function.
After reinstalling the entire system with OpenCV version 4.12, this was no longer possible.
Another reinstallation with OpenCV 4.13 also didn't produce the desired function.
Fortunately, I have an image with OpenCV 4.10. But when I install updates (sudo apt-get update; sudo apt-get upgrade), I experience the same unwanted behavior.
Unfortunately, I haven't found a precise description of the function of the various options.
I'm hoping for some good advice on how to resolve this unwanted behavior.
Thank you

[kbarni]

This is probably a libcamera update issue, not OpenCV related.
The camera is entirely controlled by libcamera (including exposire, gain, etc.) until the retrieval of the image buffer. Then the image buffer is packaged into a cv::Mat object.

[HGSvienna]

Thank you for your reply. I'm a little bit confused... Have a look on the reply I got from Raspberry Pi: https://forums.raspberrypi.com/viewtopic.php?t=390119 What shall I do? kbarni ***@***.***> schrieb am Do., 24. Juli 2025, 16:04:

…

*kbarni* left a comment (kbarni/LCCV#39) <#39 (comment)> This is probably a libcamera update issue, not OpenCV related. The camera is entirely controlled by libcamera (including exposire, gain, etc.) until the retrieval of the image buffer. Then the buffer is packaged into a cv::Mat object. — Reply to this email directly, view it on GitHub <#39 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BUZFKV6BPPRVLGWQ35ECQWT3KDRX5AVCNFSM6AAAAACBYRQ6XGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTCMJTGYYDMMBVGE> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[Chayanon-Ninyawee]

The ControlList behevior is changed

Find what you want to do here and just read how what mode need to be set to make it work
https://libcamera.org/internal-api-html/namespacelibcamera_1_1controls.html

I forked the repo and add a very stupid fix
https://github.com/Chayanon-Ninyawee/LCCV

For example:

namespace controls = libcamera::controls;
...
lccv::PiCamera cam;
libcamera::ControlList &camControls = cam.getControlList();

// To change gain you need to set AnalogueGainMode to Manual
camControls.set(controls::AnalogueGainMode, controls::AnalogueGainModeEnum::AnalogueGainModeManual);
cam.options->gain = 40.0f;

[HGSvienna]

It works! Great!
Thank you very much and all the best.