ASP.NET Core stream video from the OpenCVSharp capture

问题

I want to stream video captured from the webcam using ASP.NET Core application. I also need to do some manipulations with the frames, that's why I'm using OpenCVSharp.

Currently I have next developments:

• html in my view - here I don't know what type I should use

<video id="video" preload="auto">
  <source src="LiveVideo" type="<< don't know the type >>"/>
</video>

• my controller - here I also don't know the content type, and the main problem: I don't know how to stream the video captured by OpenCVSharp

[ApiController]
[Route("[controller]")]
public class LiveVideoController : ControllerBase 
{
  [HttpGet]
  public async Task<FileStreamResult> GetVideo()
  {
    // capture frames from webcam
    // https://github.com/shimat/opencvsharp/wiki/Capturing-Video
    var capture = new VideoCapture(0);

    var stream = await << somehow get the stream >>;

    return new FileStreamResult(stream, << don't know the content type >>);
  }
}

回答1:

If somebody needs so exotic behavior for the app, I've found a way. It is possible with Blazor. I read each frame like a bytes array and send it to the UI and convert it to the image.

Here is my Blazor component LiveVideo.razor

@page "/live-video"

@using OpenCvSharp;


<img src="@_imgSrc" />


@code {
    private string _imgSrc;

    protected override async Task OnInitializedAsync()
    {
        using (var capture = new VideoCapture(0))
        using (var frame = new Mat())
        {
            while (true)
            {
                capture.Read(frame);

                var base64 = Convert.ToBase64String(frame.ToBytes());
                _imgSrc = $"data:image/gif;base64,{base64}";

                await Task.Delay(1);

                StateHasChanged();
            }
        }
    }
}

来源：https://stackoverflow.com/questions/57514490/asp-net-core-stream-video-from-the-opencvsharp-capture