#dotnet – Display a video file🎥 in Winform using #OpenCV and #net5

Hi !

Super short post today, however is the base of the next series of posts around OpenCV and .Net 5. I already wrote on how to work with a webcam, and now it’s time to share a simple piece of code to show

How to open and process a video frame by frame

I’ve downloaded a “traffic cam” video from Youtube, and this is the output in a Winform.

Super easy ! And as usual, the source code

	using System;
	using System.Threading;
	using System.Windows.Forms;
	using OpenCvSharp;
	using OpenCvSharp.Extensions;
	using Size = OpenCvSharp.Size;
	namespace Demo13_WinFormVideoFromFile
	{
	public partial class Form1 : Form
	{
	private bool _run = false;
	private VideoCapture _capture;
	private Mat _image;
	private Thread _cameraThread;
	private string _videoFile = "4K camera example for Traffic Monitoring (Road).mp4";
	private delegate void SafeCallDelegate(string text);
	public Form1()
	{
	InitializeComponent();
	Load += Form1_Load;
	Closed += Form1_Closed;
	}
	private void Form1_Closed(object sender, EventArgs e)
	{
	_cameraThread.Interrupt();
	_capture.Release();
	}
	private void btnStart_Click(object sender, EventArgs e)
	{
	_capture = new VideoCapture(_videoFile);
	_run = true;
	}
	private void btnStop_Click(object sender, EventArgs e)
	{
	_run = false;
	}
	private void Form1_Load(object sender, EventArgs e)
	{
	_image = new Mat();
	_cameraThread = new Thread(new ThreadStart(CaptureCameraCallback));
	_cameraThread.Start();
	}
	private void CaptureCameraCallback()
	{
	while (true)
	{
	if (!_run) continue;
	var startTime = DateTime.Now;
	_capture.Read(_image);
	if (_image.Empty()) return;
	var imageRes = new Mat();
	Cv2.Resize(_image, imageRes, new Size(320, 240));
	var bmpWebCam = BitmapConverter.ToBitmap(imageRes);
	pictureBoxWebCam.Image = bmpWebCam;
	}
	}
	}
	}

view raw opencvnet5winformvideofile.cs hosted with ❤ by GitHub

And the source video

References

• OpenCVSharp, https://github.com/shimat/opencvsharp