DirectShow .Net

实例引用DirectShowLib-2005.dll，这个DLL可以到http://directshownet.sourceforge.net/直接下载使用。1、获取视频采集设备IBaseFilter接口对象的方法//获取所有视频设备名称public ArrayList GetVideoInputDevice() { return GetDeviceCollection(FilterCategory.VideoInputDevice);}private ArrayList GetDeviceCollection(Guid DeviceType) { ArrayList returnString = new ArrayList(); foreach (DsDevice ds in DsDevice.GetDevicesOfCat(DeviceType)) { returnString.Add(ds.Name); } return returnString; }//通过获取到的视频设备名称设置采集设备的IBaseFilter对象 public bool SetVideoInputDevice(string VideoInputDeviceName) { //创建视频输入设备接口 theVideoDevice = CreateFilter(FilterCategory.VideoInputDevice, VideoInputDeviceName); }//通过过滤器类型和过滤器名称获取IBaseFilter接口private IBaseFilter CreateFilter(Guid category, string friendlyname) { object source = null; Guid iid = typeof(IBaseFilter).GUID; foreach (DsDevice device in DsDevice.GetDevicesOfCat(category)) { if (device.Name.CompareTo(friendlyname) == 0) { device.Mon.BindToObject(null, null, ref iid, out source); break; } } return (IBaseFilter)source; }2、初始化基本的接口对象 private void InitInterfaces() { int hr = 0; // 获取IGraphBuilder接口对象 this.m_graphBuilder = (IGraphBuilder)new FilterGraph(); //获取ICaptureGraphBuilder2接口对象 this.m_captureGraphBuilder = (ICaptureGraphBuilder2)new CaptureGraphBuilder2(); //获取m_graphBuilder 接口对象的IMediaControl对象 this.m_mediaControl = (IMediaControl)this.m_graphBuilder; //获取m_graphBuilder 接口对象的IVideoWindow对象 this.m_videoWindow = (IVideoWindow)this.m_graphBuilder; //获取m_graphBuilder 接口对象的IMediaEventEx对象 this.m_mediaEventEx = (IMediaEventEx)this.m_graphBuilder; //设置ICaptureGraphBuilder2的IGraphBuilder接口对象为当前对象 hr = this.m_captureGraphBuilder.SetFiltergraph(this.m_graphBuilder); DsError.ThrowExceptionForHR(hr); //注册事件到应用程序的窗体上 hr = this.m_mediaEventEx.SetNotifyWindow(this.hwnPropertyPageOwner, WM_GRAPHNOTIFY, IntPtr.Zero); DsError.ThrowExceptionForHR(hr); } 3、开始视频预览public void VideoPreview() try { int hr = 0; hr = this.m_graphBuilder.AddFilter(theVideoDevice, "Video Capture"); DsError.ThrowExceptionForHR(hr); // 通过theVideoDevice（IBaseFilter）视频接口对象的Preview Pin预览 hr = this.m_captureGraphBuilder.RenderStream(PinCategory.Preview, MediaType.Video, theVideoDevice, null, null); DsError.ThrowExceptionForHR(hr); //插入SampleGrabber m_pinStill = DsFindPin.ByCategory(theVideoDevice, PinCategory.Still, 0); if (m_pinStill == null) { m_pinStill = DsFindPin.ByCategory(theVideoDevice, PinCategory.Capture, 0); } // 获取theVideoDevice的IAMVideoControl对象，对于具有Still Pin的对象可以获到，采集设备不具备Still Pin，那么该对象将为Null m_VidControl = theVideoDevice as IAMVideoControl; // 设置采集视频参数 if (this.videoHeight + this.videoWidth + this.videoStride > 0) { SetConfigParms(m_pinStill, this.videoWidth, this.videoHeight, 24); } //开始拍照功能所需的接口对象 // 获得SampleGrabber对象接口 sampGrabber = new SampleGrabber() as ISampleGrabber; // 配置sample grabber baseGrabFlt = sampGrabber as IBaseFilter; ConfigureSampleGrabber(sampGrabber); // 将sample grabber添加到图形过滤器中 hr = m_graphBuilder.AddFilter(baseGrabFlt, "Ds.NET Grabber"); DsError.ThrowExceptionForHR(hr); //通过渲染将采集设备的相关输出Pin与sample grabber对象的输入Pin连接起来 //如果采集设备提供Still Pin，则通过Still Pin连接，否则直接使用Capture Pin连接 if (m_VidControl!=null) { hr = this.m_captureGraphBuilder.RenderStream(PinCategory.Still, MediaType.Video, theVideoDevice, null, baseGrabFlt); DsError.ThrowExceptionForHR(hr); } else { hr = this.m_captureGraphBuilder.RenderStream(PinCategory.Capture, MediaType.Video, theVideoDevice, null, baseGrabFlt); DsError.ThrowExceptionForHR(hr); } //设置抓取图片相关参数 SaveSizeInfo(sampGrabber); //拍照功能所需的接口对象添加结束 // 开始将视频窗口绑定到主窗体上 hr = this.m_videoWindow.put_Owner(this.hwnVideoWindowOwner); DsError.ThrowExceptionForHR(hr); hr = this.m_videoWindow.put_WindowStyle(WindowStyle.Child | WindowStyle.ClipChildren); DsError.ThrowExceptionForHR(hr); if (this.m_videoWindow != null) { this.m_videoWindow.SetWindowPosition(0, 0, this.videoWidth, this.videoHeight); } hr = this.m_videoWindow.put_Visible(OABool.True); DsError.ThrowExceptionForHR(hr); // 开始预览采集设备采集到的视频 hr = this.m_mediaControl.Run(); DsError.ThrowExceptionForHR(hr); m_IsPreview = true; } catch { m_IsPreview = false; throw new Exception("VideoPreview函数出现异常，视频预览失败！"); } }