我知道这是一个老问题,但万一其他人偶然发现它,在 C# 中使用来自 Elgato 采集卡的视频流和 DirectShow 非常容易。这是一个创建简单图表并预览 Elgato 视频流的示例。
using DirectShowLib;
DsROTEntry rot; //Used for remotely connecting to graph
IFilterGraph2 graph;
ICaptureGraphBuilder2 captureGraph;
IBaseFilter elgatoFilter;
IBaseFilter smartTeeFilter;
IBaseFilter videoRendererFilter;
Size videoSize;
//Set the video size to use for capture and recording
videoSize = new Size(1280, 720);
//Initialize filter graph and capture graph
graph = (IFilterGraph2)new FilterGraph();
captureGraph = (ICaptureGraphBuilder2)new CaptureGraphBuilder2();
captureGraph.SetFiltergraph(graph);
rot = new DsROTEntry(graph);
//Create filter for Elgato
Guid elgatoGuid = new Guid("39F50F4C-99E1-464A-B6F9-D605B4FB5918");
Type comType = Type.GetTypeFromCLSID(elgatoGuid);
elgatoFilter = (IBaseFilter)Activator.CreateInstance(comType);
graph.AddFilter(elgatoFilter, "Elgato Video Capture Filter");
//Create smart tee filter, add to graph, connect Elgato's video out to smart tee in
smartTeeFilter = (IBaseFilter)new SmartTee();
graph.AddFilter(smartTeeFilter, "Smart Tee");
IPin outPin = GetPin(PinDirection.Output, "Video", elgatoFilter);
IPin inPin = GetPin(PinDirection.Input, smartTeeFilter);
graph.Connect(outPin, inPin);
//Create video renderer filter, add it to graph, connect smartTee Preview pin to video renderer's input pin
videoRendererFilter = (IBaseFilter)new VideoRenderer();
graph.AddFilter(videoRendererFilter, "Video Renderer");
outPin = GetPin(PinDirection.Output, "Preview", smartTeeFilter);
inPin = GetPin(PinDirection.Input, videoRendererFilter);
graph.Connect(outPin, inPin);
//Render stream from video renderer
captureGraph.RenderStream(PinCategory.Preview, MediaType.Video, videoRendererFilter, null, null);
//Set the video preview to be the videoFeed panel
IVideoWindow vw = (IVideoWindow)graph;
vw.put_Owner(videoFeed.Handle);
vw.put_MessageDrain(this.Handle);
vw.put_WindowStyle(WindowStyle.Child | WindowStyle.ClipSiblings | WindowStyle.ClipChildren);
vw.SetWindowPosition(0, 0, 1280, 720);
//Start the preview
mediaControl = graph as IMediaControl;
mediaControl.Run();
private IPin GetPin(PinDirection pinDir, IBaseFilter filter)
{
IEnumPins epins;
int hr = filter.EnumPins(out epins);
if (hr < 0)
return null;
IntPtr fetched = Marshal.AllocCoTaskMem(4);
IPin[] pins = new IPin[1];
epins.Reset();
while (epins.Next(1, pins, fetched) == 0)
{
PinInfo pinfo;
pins[0].QueryPinInfo(out pinfo);
bool found = (pinfo.dir == pinDir);
DsUtils.FreePinInfo(pinfo);
if (found)
return pins[0];
}
return null;
}
private IPin GetPin(PinDirection pinDir, string name, IBaseFilter filter)
{
IEnumPins epins;
int hr = filter.EnumPins(out epins);
if (hr < 0)
return null;
IntPtr fetched = Marshal.AllocCoTaskMem(4);
IPin[] pins = new IPin[1];
epins.Reset();
while (epins.Next(1, pins, fetched) == 0)
{
PinInfo pinfo;
pins[0].QueryPinInfo(out pinfo);
bool found = (pinfo.dir == pinDir && pinfo.name == name);
DsUtils.FreePinInfo(pinfo);
if (found)
return pins[0];
}
return null;
}