Camera fps too low on Xavier

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Xavier
9

hi, thanks for your reply, here is what I got from v4l2-ctl

ioctl: VIDIOC_ENUM_FMT
	Index       : 0
	Type        : Video Capture
	Pixel Format: 'MJPG' (compressed)
	Name        : Motion-JPEG
		Size: Discrete 1920x1080
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 352x288
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 432x240
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 320x184
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 176x144
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 160x120
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 320x240
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 640x360
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 640x480
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 800x600
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 960x720
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 1024x768
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 1280x720
			Interval: Discrete 0.032s (31.000 fps)
		Size: Discrete 1280x960
			Interval: Discrete 0.033s (30.000 fps)

	Index       : 1
	Type        : Video Capture
	Pixel Format: 'YUYV'
	Name        : YUYV 4:2:2
		Size: Discrete 1920x1080
			Interval: Discrete 0.200s (5.000 fps)
		Size: Discrete 352x288
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 432x240
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 320x184
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 176x144
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 160x120
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 320x240
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 640x360
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 640x480
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 800x600
			Interval: Discrete 0.048s (21.000 fps)
		Size: Discrete 960x720
			Interval: Discrete 0.091s (11.000 fps)
		Size: Discrete 1024x768
			Interval: Discrete 0.077s (13.000 fps)
		Size: Discrete 1280x720
			Interval: Discrete 0.111s (9.000 fps)
		Size: Discrete 1280x960
			Interval: Discrete 0.167s (6.000 fps)

I also modified my code like this

int main()
{
	VideoCapture cap(0);
	cv::VideoWriter gst_testsink;
	gst_testsink.open("appsrc ! queue ! videoconvert ! video/x-raw, format=RGBA ! nvvidconv ! nvoverlaysink ", cv::CAP_GSTREAMER, 0, 3, cv::Size(640, 480));
	cv::Mat img;

	double fps=0;

	cap.set(cv::CAP_PROP_FRAME_WIDTH,640);
	cap.set(cv::CAP_PROP_FRAME_HEIGHT,480);
	cap.set(cv::CAP_PROP_FPS,30);

	while(true)
	{
	
		if (!cap.read(img)) {
       		std::cout<<"Capture read error"<<std::endl;
       		break;
   		}
   		gst_testsink.write(img);
		//imshow("CamShow",frame);
		
		fps = cap.get(cv::CAP_PROP_FPS);
		cout<<"FPS:"<<fps<<endl;
		

		waitKey(1);
	}

	gst_testsink.release();
	cap.release();
	
	return 0;
}

when I ran the code, the output is

xavier2@xavier2-desktop:~/code/videoCapture/build$ ./videoCapture 
[ WARN:0] global /home/nvidia/host/build_opencv/nv_opencv/modules/videoio/src/cap_gstreamer.cpp (933) open OpenCV | GStreamer warning: Cannot query video position: status=0, value=-1, duration=-1
FPS:5
FPS:5
FPS:5
FPS:5
FPS:5
FPS:5
FPS:5
FPS:5
FPS:5
FPS:5

when I set width and height as 640x480 and used gstreamer pipeline I still got 5 fps,
but when I used imshow instead, it became much faster, the print of CAP_PROP_FPS was always 5,
It seemed that cap.set(cv::CAP_PROP_FPS,30) didn’t work