Text overlay when video is recording using Directshow and C#

问题

By using DirectShowLib i can able to record the video by using ASF writter here is the code to start recording

 try
        {
            IBaseFilter capFilter = null;
            IBaseFilter asfWriter = null;
            IFileSinkFilter pTmpSink = null;
            ICaptureGraphBuilder2 captureGraph = null;               
            GetVideoDevice();
            if (availableVideoInputDevices.Count > 0)
            {
                //
                //init capture graph
                //
                graphBuilder = (IFilterGraph2)new FilterGraph();
                captureGraph = (ICaptureGraphBuilder2)new CaptureGraphBuilder2();
                //
                //sets filter object from graph
                //
                captureGraph.SetFiltergraph(graphBuilder);
                //
                //which device will use graph setting
                //
                graphBuilder.AddSourceFilterForMoniker(AvailableVideoInputDevices.First().Mon, null, AvailableVideoInputDevices.First().Name, out capFilter);
                captureDeviceName = AvailableVideoInputDevices.First().Name;                    
                //
                //check saving path is exsist or not;if not then create
                //
                if (!Directory.Exists(ConstantHelper.RootDirectoryName + "\\Assets\\Video\\"))
                {
                    Directory.CreateDirectory(ConstantHelper.RootDirectoryName + "\\Assets\\Video\\");
                }
                #region WMV                   
                //
                //sets output file name,and file type
                //
                captureGraph.SetOutputFileName(MediaSubType.Asf, ConstantHelper.RootDirectoryName + "\\Assets\\Video\\" + videoFilename + ".wmv", out asfWriter, out pTmpSink);                    
                //
                //configure which video setting is used by graph
                //                
                IConfigAsfWriter lConfig = asfWriter as IConfigAsfWriter;
                Guid asfFilter = new Guid("8C45B4C7-4AEB-4f78-A5EC-88420B9DADEF");
                lConfig.ConfigureFilterUsingProfileGuid(asfFilter);
                #endregion
                //
                //render the stram to output file using graph setting
                //
                captureGraph.RenderStream(null, null, capFilter, null, asfWriter);
                m_mediaCtrl = graphBuilder as IMediaControl;
                m_mediaCtrl.Run();
                isVideoRecordingStarted = true;
                VideoStarted(m_mediaCtrl, null);

Now i want to add an text overlay on the video when video is recoding and by using DirectshowLib is this posible?

For example when video recording get start video should get recorded with an text overlay.

回答1:

I'm doing it in my software in a way that SampleGrabber filter is inserted into a graph, and upon arrival of a picture, I convert it to Bitmap object, then draw on it with Graphics.

回答2:

Look at the DMO and DxLogo examples in the DirectShow.Net samples to do what your looking for. what Daniel Mošmondor is explaining you can find in the DxSnap example...

http://directshownet.sourceforge.net/

来源：https://stackoverflow.com/questions/10847477/text-overlay-when-video-is-recording-using-directshow-and-c-sharp

标签

text

overlay

directshow

directshow.net