What is the best way to call set/get V4L2 controls from GStreamer capture ?
Good evening,
I have implemented a driver (kernel module) for a MIPI camera sensor which outputs BGGR 10-bit data (bayer). The capture interface I am using to make it work with OpenCV is GStreamer (cv::CAP_GSTREAMER). My driver interacts with the camera sensor through V4L2 implementation, more specifically I have implemented callback for VIDIOC_S_CTRL and VIDIOC_G_CTRL ioctl operations. This way, I can configure the sensor registers easily.
Unfortunately, the GStreamer interface for a cv::VideoCapture doesn't handle many V4L2 controls and I would need to implement V4L2_CID_HFLIP and V4L2_CID_VFLIP (horizontal and vertical flips).
The problem I am facing is that I can't find a way to call V4L2 callbacks from the GStreamer capture interface. For instance, it seems that I don't have any access to the file descriptor from the GStreamer capture interface in order to call some ioctl() functions.
What would be the best way to call set/get V4L2 controls from the GStreamer capture interface ?
Regards,
I have tried to get the device file descriptor from GStreamer using g_object_get(G_OBJECT(v4l2src), "device-fd", &device_fd, NULL) and using it with ioctl call, but the latter function returns "Bad file descriptor"