TX1 CSI camera display black screen

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX1
1

Hi,

Recently we test facedetect(opencv3.2 + CSI camera) on TX1.
but we found some problem:
capture can been opened,show screen is black .

we used opencv samples (videocapture_basic.cpp) for test .

Anyone can help me ,thank you .

2

Hi,

Could you help us check the gst functionality first?

Thanks.

gst-launch-1.0 nvcamerasrc fpsRange="30.0 30.0" ! 'video/x-raw(memory:NVMM), width=(int)1920, height=(int)1080, format=(string)I420, framerate=(fraction)30/1' ! nvtee ! nvvidconv flip-method=2 ! 'video/x-raw(memory:NVMM), format=(string)I420' ! nvoverlaysink -e
3

Hi, AastaLLL

nvgstcapture can show normaly.
I also check USB-camera,it’s ok.
I had searched one message about TK1:
we should modify V4L2_FRAME_BUF_SIZE from 40964096 → 34096*4096.
but I can’t verify it.
thanks.

4

Hi,

Looks like you can read camera source normally.
May I know which display function you used? Do you use cv::imshow()?

Here is simple sample for display sanity. Could you give it a try?

#include <opencv2/highgui/highgui.hpp>

int main()
{
    cv::Mat img(512,512,CV_8UC3,cv::Scalar(0));
    cv::putText(img,
        "Hello, OpenCV on Jetson!",
        cv::Point(10, img.rows / 2),
        cv::FONT_HERSHEY_DUPLEX,
        1.0,
        CV_RGB(118, 185, 0),
        2);

    cv::imshow("Hello!", img);
    cv::waitKey(0);
}

nvcc topic_1000473.cpp -lopencv_core -lopencv_highgui -o test
5

Hi, AastaLLL
As you said,we use cv::imshow()for test.
We build your sample.
The window display normally:background is black.the “Hello, OpenCV on Jetson!” is green.
Is right ?

thanks.

6

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7

Hi,

Sorry for the late reply.

Looks like your camera input and display works normally.
Could you attach source code for us better investigate?

8

Hi,

Could you share the status of this issue?
Does it fix already?

Any feedback is highly appreciated.

9

Hi, AastaLLL
I found the reason that:
The CSI camera need ISP,gst(with NVT pluge) only open it.
So I use follow code:

const char* gst =  "nvcamerasrc ! video/x-raw(memory:NVMM), width=(int)640, height=(int)360, format=(string)I420, framerate=(fraction)30/1 ! \
                    nvvidconv flip-method=2 ! video/x-raw, format=(string)I420 ! \
                    videoconvert ! video/x-raw, format=(string)BGR ! \
                    appsink";

    cv::VideoCapture cap(gst);

It’s ok,thank u.