如何将 MediaCapture 更改为 Byte[] [英] How to change MediaCapture to Byte[]

问题描述

如何在 Windows 8.1 的 Windows 应用商店应用程序中将 MediaCapture 更改为 byte[].来自库:

How to change MediaCapture to byte[] in Windows Store App for Windows 8.1. From lib:

Windows.Media.Capture.MediaCapture asd = newWindows.Media.Capture.MediaCapture();

Windows.Media.Capture.MediaCapture asd = new Windows.Media.Capture.MediaCapture();

谢谢！

推荐答案

我假设您想从相机目前看到的内容中获取一个字节数组，尽管很难从您的问题中解释.

I assume you want to get a byte array from what the camera is seeing at the moment, although it's hard to interpret from your question.

Microsoft github 页面上有一个相关示例，尽管它们针对的是 Windows 10.您可能有兴趣迁移您的项目以获得此功能.

There is a sample on the Microsoft github page that is relevant, although they target Windows 10. You may be interested in migrating your project to get this functionality.

GetPreviewFrame:此示例将捕获预览帧而不是完整的照片，但它应该是一个不错的选择初始点.有了预览框后，就可以编辑上面的像素了.

GetPreviewFrame: This sample will capture preview frames as opposed to full-blown photos, but it should be a good starting point. Once it has a preview frame, it can edit the pixels on it.

以下是相关部分:

private async Task GetPreviewFrameAsSoftwareBitmapAsync()
{
    // Get information about the preview
    var previewProperties = _mediaCapture.VideoDeviceController.GetMediaStreamProperties(MediaStreamType.VideoPreview) as VideoEncodingProperties;

    // Create the video frame to request a SoftwareBitmap preview frame
    var videoFrame = new VideoFrame(BitmapPixelFormat.Bgra8, (int)previewProperties.Width, (int)previewProperties.Height);

    // Capture the preview frame
    using (var currentFrame = await _mediaCapture.GetPreviewFrameAsync(videoFrame))
    {
        // Collect the resulting frame
        SoftwareBitmap previewFrame = currentFrame.SoftwareBitmap;

        // Add a simple green filter effect to the SoftwareBitmap
        EditPixels(previewFrame);
    }
}

private unsafe void EditPixels(SoftwareBitmap bitmap)
{
    // Effect is hard-coded to operate on BGRA8 format only
    if (bitmap.BitmapPixelFormat == BitmapPixelFormat.Bgra8)
    {
        // In BGRA8 format, each pixel is defined by 4 bytes
        const int BYTES_PER_PIXEL = 4;

        using (var buffer = bitmap.LockBuffer(BitmapBufferAccessMode.ReadWrite))
        using (var reference = buffer.CreateReference())
        {
            // Get a pointer to the pixel buffer
            byte* data;
            uint capacity;
            ((IMemoryBufferByteAccess)reference).GetBuffer(out data, out capacity);

            // Get information about the BitmapBuffer
            var desc = buffer.GetPlaneDescription(0);

            // Iterate over all pixels
            for (uint row = 0; row < desc.Height; row++)
            {
                for (uint col = 0; col < desc.Width; col++)
                {
                    // Index of the current pixel in the buffer (defined by the next 4 bytes, BGRA8)
                    var currPixel = desc.StartIndex + desc.Stride * row + BYTES_PER_PIXEL * col;

                    // Read the current pixel information into b,g,r channels (leave out alpha channel)
                    var b = data[currPixel + 0]; // Blue
                    var g = data[currPixel + 1]; // Green
                    var r = data[currPixel + 2]; // Red

                    // Boost the green channel, leave the other two untouched
                    data[currPixel + 0] = b;
                    data[currPixel + 1] = (byte)Math.Min(g + 80, 255);
                    data[currPixel + 2] = r;
                }
            }
        }
    }
}

并在课堂外声明:

[ComImport]
[Guid("5b0d3235-4dba-4d44-865e-8f1d0e4fd04d")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
unsafe interface IMemoryBufferByteAccess
{
    void GetBuffer(out byte* buffer, out uint capacity);
}

仔细查看示例以了解如何获取所有详细信息.或者，要进行演练，您可以观看来自最近的//build/会议，其中包括一些相机示例的演练.

Have a closer look at the sample to see how to get all the details. Or, to have a walkthrough, you can watch the camera session from the recent //build/ conference, which includes a little bit of a walkthrough through some camera samples.

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