WPF中使用DirectShowLib枚举摄像头设备和分辨率

1. 定义设备接口

public interface IDevice{
    string DeviceName{get;set;}  //设备名称
    string DevicePath{get;set;}  //设备路径
    System.Runtime.InteropServices.ComTypes.IMoniker Moniker{get;set;}
}

2.展台设备接口

public class CameraDevice : IDevice{
    // - interface IDevice -
    public string DeviceName{get;set;}
    public string DevicePath{ get; set; }
    public System.Runtime.InteropServices.ComTypes.IMoniker Moniker{get;set;}
    // end IDevice

    //分辨率结构体
    public struct Resolution{
        public double Width{set;set;}
        public double Height{get;set;}
    }

    public CameraDevice(){
        this.DevicePath = string.Empty;
        this.DeviceName = string.Empty;
    }
}

3. 服务类，实现利用DirectShowLib获取设备的分辨率,本质还是DX接口的运用

public class DeviceService
{
    // 获取系统内安装的视频输入设备~
    public System.Collections.Generic.IList<IDevice> GetDevices()
    {
        DsDevice[] devicesOfCat = DsDevice.GetDevicesOfCat(FilterCategory.VideoInputDevice);
        System.Collections.Generic.IList<IDeviceInfo> list = new System.Collections.Generic.List<IDeviceInfo>();
        DsDevice[] array = devicesOfCat;

        for( int i  = 0 ; i < array.length ; i++ ){
            DsDevice dsdevice = array[i];
            list.Add({new CameraDevice{
                DeviceName = dsdevice.Name,
                DevicePath = dsdevice.DevicePath,
                Moniker  = dsdevice.Mon
            }});
        }

        return list;
    }

    public System.Collections.Generic.IList<CameraDevice.Resolution> GetResolutions(string devicePath)
    {
        //获取设备
        System.Collections.Generic.IList<IDevice> devices= this.GetDevices();
        foreach( IDevice current in devices)
        {
            //获取当前指定设备路径的关联分辨率
            if( current.DevicePath == devicePath ){
                return this.GetResolutions(current);
            }
        }

        return new System.Collections.Generic.List<CameraDevice.Resolution>();
    }

 private System.Collections.Generic.IList<CameraDevice.Resolution> GetResolutions(IDevice deivce)
 {
     System.Collections.Generic.List<CameraDevice.Resolution> list = new System.Collections.Generic.List<CameraDevice.Resolution>();
     IBaseFilter vSource = null;
    IFilterGraph2 filterGraph = new FilterGraph() as IFilterGraph2;
    if (filterGraph == null)
     {
          return list;
     }
     filterGraph.AddSourceFilterForMoniker(deivce.Moniker, null, deivce.DeviceName, out vSource);
     IPin pin = DsFindPin.ByCategory(vSource, PinCategory.Capture, 0);
     VideoInfoHeader videoInfoHeader = new VideoInfoHeader();
     IEnumMediaTypes enumMediaTypes;
     pin.EnumMediaTypes(out enumMediaTypes);
     AMMediaType[] array = new AMMediaType[1];
     System.IntPtr zero = System.IntPtr.Zero;
     enumMediaTypes.Next(1, array, zero);
     int num = 0;
     int num2 = 0;
     while (array.Any<AMMediaType>() && array[0] != null)
     {
        System.Runtime.InteropServices.Marshal.PtrToStructure(array[0].formatPtr, videoInfoHeader);
        if (videoInfoHeader.BmiHeader.Size != 0 && videoInfoHeader.BmiHeader.BitCount != 0)
         {
            if ((int)videoInfoHeader.BmiHeader.BitCount > num2)
            {
                list.Clear();
                num = 0;
                num2 = (int)videoInfoHeader.BmiHeader.BitCount;
            }

            list.Add(new CameraDevice.Resolution
            {
                Width = (double)videoInfoHeader.BmiHeader.Width,
                Height = (double)videoInfoHeader.BmiHeader.Height
            });

            if (videoInfoHeader.BmiHeader.Width > num || videoInfoHeader.BmiHeader.Height > num)
            {
                num = System.Math.Max(videoInfoHeader.BmiHeader.Width, videoInfoHeader.BmiHeader.Height);
            }
         }
         enumMediaTypes.Next(1, array, zero);
     } 

     return (from d in list.Distinct<CameraDevice.Resolution>()
                    orderby d.Width
                    select d).ToList<CameraDevice.Resolution>();
  }
}

4. 测试：新建WPF工程，一个按钮。 click事件

private void _btnGetDevices_Click_1(object sender, RoutedEventArgs e)
 {
            DeviceService videoservice = new DeviceService();
            IList<IDevice> deviceinfos = videoservice.GetDevices();
            if (deviceinfos != null && deviceinfos.Count > 0)
            {
                IDevice d = deviceinfos[0];
                List<CameraDevice.Resolution> ls = videoservice.GetResolutions(d).ToList<CameraDevice.Resolution>();
                string strmsg = string.Empty;
                strmsg += "device count:" + deviceinfos.Count.ToString() + "\n";
                strmsg += "device name:" + d.DeviceName + "\n";
                foreach (CameraDevice.Resolution cur in ls)
                {
                    strmsg += "RW:" + cur.Width + " ; RH: " + cur.Height + "\n";
                }

                MessageBox.Show(strmsg);
            }
}