ASP.NET 来自 OpenCVSharp 捕获的核心流视频

Question

我想使用 ASP.NET 核心应用程序流式传输从网络摄像头捕获的视频。我还需要对帧进行一些操作，这就是我使用 OpenCVSharp 的原因。

目前我有下一步的发展：

html 在我看来-在这里我不知道我应该使用什么类型

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

我的控制器 - 这里我也不知道内容类型，主要问题是：我不知道如何流式传输 OpenCVSharp 捕获的视频

[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 >>);
  }
}

Answer 1

如果有人需要应用程序如此奇特的行为，我已经找到了一种方法。使用 Blazor 是可能的。我像字节数组一样读取每一帧并将其发送到 UI 并将其转换为图像。

这是我的 Blazor 组件 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();
            }
        }
    }
}

Answer 2

试试这个参考下面的项目文件

    <Project Sdk="Microsoft.NET.Sdk.BlazorWebAssembly">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <WasmBuildNative>true</WasmBuildNative>
    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
  </PropertyGroup>

  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
    <RunAOTCompilation>True</RunAOTCompilation>
  </PropertyGroup>

  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
    <RunAOTCompilation>True</RunAOTCompilation>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly" Version="6.0.1" />
    <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.DevServer" Version="6.0.1" PrivateAssets="all" />
    <PackageReference Include="OpenCvSharp4" Version="4.5.5.20211231" />
    <PackageReference Include="OpenCvSharp4.runtime.wasm" Version="4.5.5.20211231" />
  </ItemGroup>

</Project>

查看 Sample code

ASP.NET 来自 OpenCVSharp 捕获的核心流视频

ASP.NET Core stream video from the OpenCVSharp capture

opencv

asp.net-core

opencvsharp