Save image from Elgato Game Capture using DirectShow - image

Question

Im using a Elgato Game Capture HD60 to live prewview a GoPro Hero 5 in my application. Now i want to save the stream as a JPG in my folder. But i cant find out how to.
To bind the pin
DsROTEntry rot; //Used for remotely connecting to graph
IFilterGraph2 graph;
ICaptureGraphBuilder2 captureGraph;
IBaseFilter elgatoFilter;
IBaseFilter smartTeeFilter;
IBaseFilter videoRendererFilter;
Size videoSize;
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;
}
And to start the stream
private void button1_Click(object sender, EventArgs e)
{
//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(pictureBox1.Handle);
vw.put_MessageDrain(this.Handle);
vw.put_WindowStyle(WindowStyle.Child | WindowStyle.ClipSiblings | WindowStyle.ClipChildren);
vw.SetWindowPosition(0, 0, 1280, 720);
//Start the preview
IMediaControl mediaControl = graph as IMediaControl;
mediaControl.Run();
}

Answer 1

Can you run the filter graph successfully, and which step did you get error info?
You can get sample code \Samples\Capture\PlayCap to see how to build video capture filter graph.
If you want to get a video snapshot, you can get the sample code at \Samples\Capture\DxSnap.
You can modify the video source index and video snapshot size to get what you want.
const int VIDEODEVICE = 0; // zero based index of video capture device to use
const int VIDEOWIDTH = 2048; // Depends on video device caps
const int VIDEOHEIGHT = 1536; // Depends on video device caps
const int VIDEOBITSPERPIXEL = 24; // BitsPerPixel values determined by device