Fast Video Display WPF

Question

I am working on a WPF application that needs to display several video streams at a fast frame rate (we would like 30 fps). The video streams are 1920x1080 raw (RGB24) frames (th

Answer 1

Anyone looking for a solution, we wrote a custom winforms control using DirectX 11 with a highly optimized copy into graphics memory, then hosted the control in a WinformsHost, I can provide some code to anyone who is interested.

Optimized copy into gpu memory

    // Using native memcpy for the fastest possible copy
    [DllImport("msvcrt.dll", EntryPoint = "memcpy", CallingConvention = CallingConvention.Cdecl, SetLastError = false)]
    private static extern IntPtr memcpy(IntPtr dest, IntPtr src, UIntPtr count);

    /// 

    /// Copies a bitmap to gpu memory
    /// 
    /// The image to copy to the gpu
    /// A texture in gpu memory for the bitmap
    public Texture2D CopyFrameToGpuMemory(Bitmap frame)
    {
        SampleDescription sampleDesc = new SampleDescription();
        sampleDesc.Count = 1;
        sampleDesc.Quality = 0;

        Texture2DDescription texDesc = new Texture2DDescription()
        {
            ArraySize = 1,
            MipLevels = 1,
            SampleDescription = sampleDesc,
            Format = Format.B8G8R8A8_UNorm,
            CpuAccessFlags = CpuAccessFlags.Write,
            BindFlags = BindFlags.ShaderResource,
            Usage = ResourceUsage.Dynamic,
            Height = frame.Height,
            Width = frame.Width
        };

        Texture2D tex = new Texture2D(Device, texDesc);

        Surface surface = tex.AsSurface();
        DataRectangle mappedRect = surface.Map(SlimDX.DXGI.MapFlags.Write | SlimDX.DXGI.MapFlags.Discard);

        BitmapData pixelData = frame.LockBits(new Rectangle(0, 0, frame.Width, frame.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppRgb);

        unsafe //!!!
        {
            byte* pixelDataStart = (byte*)pixelData.Scan0.ToPointer();
            byte* mappedRectDataStart = (byte*)mappedRect.Data.DataPointer.ToPointer();

            for (int y = 0; y < texDesc.Height; y++)
            {
                byte* lineLocationDest = mappedRectDataStart + (y * mappedRect.Pitch);
                byte* lineLocationSrc = pixelDataStart + (y * pixelData.Stride);

                // Copy line by line for best performance
                memcpy((IntPtr)lineLocationDest, (IntPtr)lineLocationSrc, (UIntPtr)(texDesc.Width * 4));
            }
        } //!!!

        frame.UnlockBits(pixelData);

        mappedRect.Data.Dispose();

        surface.Unmap();
        surface.Dispose();

        return tex;
    }