// disconnect all connected audio out pins and remove unused filters
        private void StripSplitter(IGraphBuilder pGraphBuilder)
        {
            if (_splitterFilter != null)
            {
                IPin pPin  = null;
                int  nSkip = 0;

                while ((pPin = DsUtils.GetPin(_splitterFilter, PinDirection.Output, true, nSkip)) != null)
                {
                    if (DsUtils.IsMediaTypeSupported(pPin, MediaType.Audio) == 0 ||
                        DsUtils.IsMediaTypeSupported(pPin, MediaType.Subtitle) == 0)
                    {
                        // this connected pin supports audio or subpicture type!
                        DsUtils.Disconnect(pGraphBuilder, pPin);
                    }
                    else
                    {
                        nSkip++;
                    }
                    Marshal.ReleaseComObject(pPin);
                } // end of while

                DsUtils.RemoveRedundantFilters(_sourceFilter, pGraphBuilder);
            }
        }
 public void RenderSubpicture(IGraphBuilder pGraphBuilder, IRenderer renderer)
 {
     if (FindSplitter(pGraphBuilder))
     {
         _subpictureStreamHandler = SubpictureStreamHandlerFactory.GetHandler(_splitterFilter);
         if (_subpictureStreamHandler != null)
         {
             _subpictureStreamHandler.RenderSubpicture(pGraphBuilder, _splitterFilter, renderer);
             DsUtils.RemoveRedundantFilters(_sourceFilter, pGraphBuilder);
         }
     }
 }
        // this function should be called AFTER the video stream has been rendered
        // but before rendering the audio streams
        // however, it will try to find the splitter even if video wasn't rendered
        private bool FindSplitter(IGraphBuilder pGraphBuilder)
        {
            if (_splitterFilter != null)
            {
                DsUtils.RemoveRedundantFilters(_sourceFilter, pGraphBuilder);
                return(true);
            }

            IEnumFilters pEnumFilters = null;
            IBaseFilter  pFilter      = null;
            int          cFetched;
            bool         bSplitterFound = false;

            int hr = pGraphBuilder.EnumFilters(out pEnumFilters);

            if (DsHlp.FAILED(hr))
            {
                return(false);
            }

            IPin pPin;
            int  nFilters = 0;
            bool bCanRelease;

            while ((pEnumFilters.Next(1, out pFilter, out cFetched) == DsHlp.S_OK))
            {
                nFilters++;
                bCanRelease = true;
                pPin        = DsUtils.GetPin(pFilter, PinDirection.Output, false, 0);
                if (pPin != null)
                {
                    if (DsUtils.IsMediaTypeSupported(pPin, MediaType.Audio) == 0 ||
                        DsUtils.IsMediaTypeSupported(pPin, MediaType.Subtitle) == 0)
                    {
                        //this unconnected pin supports audio or subpicture type!
                        bSplitterFound  = true;
                        bCanRelease     = false;
                        _splitterFilter = pFilter;
                    }
                    Marshal.ReleaseComObject(pPin);
                }

                //let's have a look at another filter
                if (bCanRelease)
                {
                    Marshal.ReleaseComObject(pFilter);
                }

                if (bSplitterFound)
                {
                    break;
                }
            }

            Marshal.ReleaseComObject(pEnumFilters);

            if (!bSplitterFound)
            {
                if (nFilters > 3)
                {
                    pPin = DsUtils.GetPin(_sourceFilter, PinDirection.Output, true, 0);
                    if (pPin != null)
                    {
                        IPin pInputPin;
                        hr = pPin.ConnectedTo(out pInputPin);
                        if (hr == DsHlp.S_OK)
                        {
                            PinInfo info = new PinInfo();
                            hr = pInputPin.QueryPinInfo(out info);
                            if (hr == DsHlp.S_OK)
                            {
                                _splitterFilter = info.pFilter;
                                bSplitterFound  = true;
                            }
                            Marshal.ReleaseComObject(pInputPin);
                        }
                        Marshal.ReleaseComObject(pPin);
                    }
                }
                else
                {
                    _splitterFilter = _sourceFilter;
                    bSplitterFound  = true;
                }
            }

            StripSplitter(pGraphBuilder);
            return(bSplitterFound);
        }