~~tag> VIM4 OpenCV V4l2 MIPI ISP ~~

{{indexmenu_n>50}}

====== VIM4 MIPI Camera Usage ======

===== Linux =====

==== Upgrade System ====

Please follow the [[products:sbc:vim4:configurations:upgrade-system|documentation ]]to upgrade your system to latest version.

==== Video Node ====

The video node for MIPI camera is ''/dev/video50''.

==== Record Video via Gstreamer ====


Follow the steps below to install Gstreamer Encoder Plugin:

```shell
sudo apt update
sudo apt install gstreamer-aml
```

Record Video:

```shell
gst-launch-1.0 -e v4l2src device=/dev/video50 io-mode=mmap num-buffers=300 ! video/x-raw,format=NV21,width=3840,height=2160,framerate=30/1 ! amlvenc bitrate=8000 ! h264parse ! qtmux ! filesink location=test_50.mp4
```


==== Record Video with OpenCV ====

Follow the steps below to install OpenCV:

```shell
sudo apt update
sudo apt install libopencv-dev python3-opencv
```

Get Frame via V4l2:

```c++ mipi-camera.cpp
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/core/core.hpp>
#include <iostream>
#include <string>
using
namespace  cv;

using
namespace  std;

int main(int argc, char** argv)
{
    int count=100;
    string str = argv[1];
    string res=str.substr(10);
    VideoCapture capture(stoi(res), CAP_V4L2);
    capture.set(CAP_PROP_FOURCC, VideoWriter::fourcc('U','Y','V','Y'));
    capture.set(CAP_PROP_FRAME_WIDTH, 3840);
    capture.set(CAP_PROP_FRAME_HEIGHT, 2160);
    while (count)
    {
        Mat frame;
        capture >> frame;

        if (frame.empty()) {
            break;
        }
        int h = frame.rows;
        int w = frame.cols;
        const char *name = "video";
        namedWindow(name, 0);
        imshow(name, frame);
        waitKey(30);
        count--;
    }
    return 0;
}

```

Get Frame via Gstreamer:

```c++ mipi-camera.cpp
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/core/core.hpp>
#include <iostream>
#include <string>
using
namespace  cv;

using
namespace  std;

int main(int argc, char** argv)
{
    int count=100;
    string str = argv[1];
    string gstformat = "NV12";
    string gstfile = "v4l2src device=" + str + " ! video/x-raw,format=" + gstformat + ",width=3840,height=2160,framerate=30/1 ! videoconvert ! appsink";
    VideoCapture capture(gstfile);

    while (count)
    {
        Mat frame;
        capture >> frame;

        if (frame.empty()) {
            break;
        }
        int h = frame.rows;
        int w = frame.cols;
        const char *name = "video";
        namedWindow(name, 0);
        imshow(name, frame);
        waitKey(30);
        count--;
    }
    return 0;
}

```

Compile:

```shell
gcc -o mipi mipi-camera.cpp -lopencv_imgproc -lopencv_core -lopencv_videoio -lopencv_imgcodecs -lopencv_highgui -std=c++11 -std=gnu++11 -Wall -std=c++11 -lstdc++ -I/usr/include/opencv4
```

Test:

```shell
./mipi /dev/video50
```

==== Preview video on ubuntu desktop ====

<tabbox Ubuntu 24.04>

You can use gstreamer ''waylandsink'' to preview the video on Ubuntu Wayland desktop:

```shell
gst-launch-1.0 v4l2src device=/dev/video50 io-mode=mmap  ! video/x-raw,format=NV12,width=3840,height=2160,framerate=30/1 ! videoconvert ! waylandsink
```

You can use the command below to check display fps:

```shell
gst-launch-1.0 -v v4l2src device=/dev/video50 io-mode=mmap ! video/x-raw,format=NV12,width=3840,height=2160,framerate=30/1 ! fpsdisplaysink video-sink=waylandsink sync=false text-overlay=false
```

<tabbox Ubuntu 22.04>

You can use gstreamer ''clutterautovideosink'' to preview the video on Ubuntu Wayland desktop:

```shell
gst-launch-1.0 v4l2src device=/dev/video50 io-mode=mmap ! video/x-raw,format=NV12,width=3840,height=2160,framerate=30/1 ! clutterautovideosink
```

You can use the command below to check display fps:

```shell
gst-launch-1.0 -v v4l2src device=/dev/video50 io-mode=mmap ! video/x-raw,format=NV12,width=3840,height=2160,framerate=30/1 ! fpsdisplaysink video-sink=clutterautovideosink sync=false text-overlay=true
```

You press ''Alt + F7'' and then move mouse to move the windown.

</tabbox>

===== Android =====
WIP: