如何定期将图像添加到WebApi中的PushStreamContent？

Question

我想每100毫秒从服务器向客户端发送32KB图像。

如果我只是将每个渲染图像发送给大量数据。我只想发送更改的像素。因此，我想利用内置此功能的视频流。

客户端应该能够使用html video标签，并且我需要经常向该视频流添加最新的位图。

我尝试使用.net webapi和PushStreamContent来实现它，但是video标签只是不断加载，并且没有发生错误。

我以一个工作示例作为起点： Frame-by-frame MJPEG streaming with C#/ASP.NET MVC

这样做是正确的方法吗？

    [HttpGet]
    public HttpResponseMessage GetVideoContent()
    {
        //myImageFacade.StartImageReading();
        var response = Request.CreateResponse();
        response.Content = new PushStreamContent((Action<Stream, HttpContent, TransportContext>)StartStream);
        response.Content.Headers.ContentType = System.Net.Http.Headers.MediaTypeHeaderValue.Parse("multipart/x-mixed-replace; boundary=" + BOUNDARY);
        return response;
    }



    private byte[] CreateHeader(int length)
    {
        string header =
            "--" + BOUNDARY + "\r\n" +
            "Content-Type:image/jpeg\r\n" +
            "Content-Length:" + length + "\r\n\r\n";

        return Encoding.ASCII.GetBytes(header);
    }

    public byte[] CreateFooter()
    {
        return Encoding.ASCII.GetBytes("\r\n");
    }

    private void WriteFrame(Stream stream)
    {
        // prepare image data
        byte[] imageData = null;

        var aNewFrame = GetDummyBitmap();

        System.Drawing.Bitmap bmp;
        using (MemoryStream outStream = new MemoryStream())
        {
            JpegBitmapEncoder enc = new JpegBitmapEncoder();
            enc.Frames.Add(BitmapFrame.Create((BitmapSource)aNewFrame));
            enc.Save(outStream);
            bmp = new System.Drawing.Bitmap(outStream);

            imageData = outStream.ToArray();
        }

        // prepare header
        byte[] header = CreateHeader(imageData.Length);
        // prepare footer
        byte[] footer = CreateFooter();

        // Start writing data
        stream.Write(header, 0, header.Length);
        stream.Write(imageData, 0, imageData.Length);
        stream.Write(footer, 0, footer.Length);
    }



    private WriteableBitmap GetDummyBitmap()
    {
        string aDummyJpegMini = "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";
        byte[] theByteData = Convert.FromBase64String(aDummyJpegMini);

        try
        {
            var aBitmap = new Bitmap(21, 24, System.Drawing.Imaging.PixelFormat.Format24bppRgb);

            var aBitmapData = aBitmap.LockBits(new Rectangle(0, 0, aBitmap.Width, aBitmap.Height), ImageLockMode.WriteOnly, aBitmap.PixelFormat);
            Marshal.Copy(theByteData, 0, aBitmapData.Scan0, theByteData.Length);
            aBitmap.UnlockBits(aBitmapData);

            var aData = aBitmapData;

            WriteableBitmap aBmp = new WriteableBitmap(
                aData.Width,
                aData.Height,
                96,
                96,
                PixelFormats.Bgr24,
                null);
            int aLen = aData.Height * aData.Stride;
            aBmp.WritePixels(new Int32Rect(0, 0, aData.Width, aData.Height), aData.Scan0, aLen, aData.Stride, 0, 0);

            return aBmp;

        }
        catch (Win32Exception ex)
        {
        }
        catch (Exception ex)
        {
        }
        return null;
    }