如何列出相机可用的视频分辨率

本文关键字：的视频 分辨率 何列出 相机 | 更新日期: 2023-09-27 18:09:07

如果我有一个以上的相机连接到我的电脑…我想知道特定相机的最佳可用分辨率…

例如，一些摄像机是高清或全高清(1,280×720像素(720p)或1,920×1,080像素(1080i/1080p))或最常见的是网络摄像机....

我想知道至少最好的视频模式，相机工作正常…(相机的工作模式)

我的工作是在WPF使用c#(我使用Directshow)

thanks in advance

如何列出相机可用的视频分辨率

这是我写的代码，它对我来说工作得很好

public static List<Point> GetAllAvailableResolution(DsDevice vidDev)
{
    try
    {
        int hr;
        int max = 0;
        int bitCount = 0;
        IBaseFilter sourceFilter = null;
        var m_FilterGraph2 = new FilterGraph() as IFilterGraph2;
        hr = m_FilterGraph2.AddSourceFilterForMoniker(vidDev.Mon, null, vidDev.Name, out sourceFilter);
        var pRaw2 = DsFindPin.ByCategory(sourceFilter, PinCategory.Capture, 0);
        var AvailableResolutions = new List<Point>();
        VideoInfoHeader v = new VideoInfoHeader();
        IEnumMediaTypes mediaTypeEnum;
        hr = pRaw2.EnumMediaTypes(out mediaTypeEnum);
        AMMediaType[] mediaTypes = new AMMediaType[1];
        IntPtr fetched = IntPtr.Zero;
        hr = mediaTypeEnum.Next(1, mediaTypes, fetched);
        while (fetched != null && mediaTypes[0] != null)
        {
            Marshal.PtrToStructure(mediaTypes[0].formatPtr, v);
            if (v.BmiHeader.Size != 0 && v.BmiHeader.BitCount != 0)
            {
                if (v.BmiHeader.BitCount > bitCount)
                {
                    AvailableResolutions.Clear();
                    max = 0;
                    bitCount = v.BmiHeader.BitCount;
                }
                AvailableResolutions.Add(new Point(v.BmiHeader.Width, v.BmiHeader.Height));
                if (v.BmiHeader.Width > max || v.BmiHeader.Height > max)
                    max = (Math.Max(v.BmiHeader.Width, v.BmiHeader.Height));
            }
            hr = mediaTypeEnum.Next(1, mediaTypes, fetched);
        }
        return AvailableResolutions;
    }
    catch (Exception ex)
    {
        Log(ex);
        return new List<Point>();
    }
}

(如。这可以添加到WPF-MediaKit中的VideoCaptureElement)

我使用这个来获得最大帧大小，只需更改以适应您的需要;)

private Point GetMaxFrameSize(IPin pStill)
    {
        VideoInfoHeader v;
        IAMStreamConfig videoStreamConfig = pStill as IAMStreamConfig;
        int iCount = 0, iSize = 0;
        videoStreamConfig.GetNumberOfCapabilities(out iCount, out iSize);
        IntPtr TaskMemPointer = Marshal.AllocCoTaskMem(iSize);
        int iMaxHeight = 0;
        int iMaxWidth = 0;
        for (int iFormat = 0; iFormat < iCount; iFormat++)
        {
            AMMediaType pmtConfig = null;
            IntPtr ptr = IntPtr.Zero;
            videoStreamConfig.GetStreamCaps(iFormat, out pmtConfig, TaskMemPointer);
            v = (VideoInfoHeader)Marshal.PtrToStructure(pmtConfig.formatPtr, typeof(VideoInfoHeader));
            if (v.BmiHeader.Width > iMaxWidth)
            {
                iMaxWidth = v.BmiHeader.Width;
                iMaxHeight = v.BmiHeader.Height;
            }
            DsUtils.FreeAMMediaType(pmtConfig);
        }
        Marshal.FreeCoTaskMem(TaskMemPointer);

        return new Point(iMaxWidth, iMaxHeight);
    }

    /// <summary>
    ///  Free the nested structures and release any
    ///  COM objects within an AMMediaType struct.
    /// </summary>
    public static void FreeAMMediaType(AMMediaType mediaType)
    {
        if (mediaType != null)
        {
            if (mediaType.formatSize != 0)
            {
                Marshal.FreeCoTaskMem(mediaType.formatPtr);
                mediaType.formatSize = 0;
                mediaType.formatPtr = IntPtr.Zero;
            }
            if (mediaType.unkPtr != IntPtr.Zero)
            {
                Marshal.Release(mediaType.unkPtr);
                mediaType.unkPtr = IntPtr.Zero;
            }
        }
    }

根据本网页:http://www.e-consystems.com/blog/camera/?p=651，您应该使用此调用来获取此设备的功能:

g_DShowCaptureGraph.GetNumberOfCapabilities(nStream, &iCount, &iSize);
g_DShowCaptureGraph.GetStreamCaps(nStream,iFormat, &pmtConfig, (BYTE*)&scc);

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