/// <summary>
/// Disconnect and remove all filters except the device
/// and compressor filters. This is the opposite of
/// renderGraph(). Soem properties such as FrameRate
/// can only be set when the device output pins are not
/// connected.
/// </summary>
protected void DerenderGraph()
{
// Stop the graph if it is running (ignore errors)
MediaControl?.Stop();
// Free the preview window (ignore errors)
if (VideoWindow != null)
{
VideoWindow.put_Visible(CoreStreaming.DsHlp.OAFALSE);
VideoWindow.put_Owner(IntPtr.Zero);
VideoWindow = null;
}
// Remove the Resize event handler
if (PreviewWindow != null)
{
PreviewWindow.SizeChanged -= OnPreviewWindowResize;
}
if ((int)ActualGraphState >= (int)GraphState.Rendered)
{
// Update the state
ActualGraphState = GraphState.Created;
IsPreviewRendered = false;
// Disconnect all filters downstream of the
// video and audio devices. If we have a compressor
// then disconnect it, but don't remove it
if (VideoDeviceFilter != null)
{
RemoveDownstream(VideoDeviceFilter, VideoCompressor == null);
}
}
}
/// <summary>
/// Completely tear down a filter graph and
/// release all associated resources.
/// </summary>
protected void DestroyGraph()
{
// Derender the graph (This will stop the graph
// and release preview window. It also destroys
// half of the graph which is unnecessary but
// harmless here.) (ignore errors)
try { DerenderGraph(); }
catch { }
// Update the state after derender because it
// depends on correct status. But we also want to
// update the state as early as possible in case
// of error.
ActualGraphState = GraphState.Null;
IsPreviewRendered = false;
// Remove filters from the graph
// This should be unnecessary but the Nvidia WDM
// video driver cannot be used by this application
// again unless we remove it. Ideally, we should
// simply enumerate all the filters in the graph
// and remove them. (ignore errors)
if (VideoCompressorFilter != null)
{
GraphBuilder.RemoveFilter(VideoCompressorFilter);
}
if (VideoDeviceFilter != null)
{
GraphBuilder.RemoveFilter(VideoDeviceFilter);
}
// Cleanup
if (GraphBuilder != null)
{
Marshal.ReleaseComObject(GraphBuilder);
}
GraphBuilder = null;
if (CaptureGraphBuilder != null)
{
Marshal.ReleaseComObject(CaptureGraphBuilder);
}
CaptureGraphBuilder = null;
if (VideoDeviceFilter != null)
{
Marshal.ReleaseComObject(VideoDeviceFilter);
}
VideoDeviceFilter = null;
if (VideoCompressorFilter != null)
{
Marshal.ReleaseComObject(VideoCompressorFilter);
}
VideoCompressorFilter = null;
// These are copies of graphBuilder
MediaControl = null;
VideoWindow = null;
// For unmanaged objects we haven't released explicitly
GC.Collect();
}
/// <summary>
/// Connects the filters of a previously created graph
/// (created by CreateGraph()). Once rendered the graph
/// is ready to be used. This method may also destroy
/// streams if we have streams we no longer want.
/// </summary>
protected void RenderGraph()
{
var didSomething = false;
const int WS_CHILD = 0x40000000;
const int WS_CLIPCHILDREN = 0x02000000;
const int WS_CLIPSIBLINGS = 0x04000000;
// Stop the graph
MediaControl?.Stop();
// Create the graph if needed (group should already be created)
CreateGraph();
// Derender the graph if we have a capture or preview stream
// that we no longer want. We can't derender the capture and
// preview streams seperately.
// Notice the second case will leave a capture stream intact
// even if we no longer want it. This allows the user that is
// not using the preview to Stop() and Start() without
// rerendering the graph.
if (!WantPreviewRendered && IsPreviewRendered)
{
DerenderGraph();
}
// Render preview stream (only if necessary)
if (WantPreviewRendered && !IsPreviewRendered)
{
// Render preview (video -> renderer)
var cat = Uuid.PinCategory.Preview;
var med = Uuid.MediaType.Video;
var hr = CaptureGraphBuilder.RenderStream(ref cat, ref med, VideoDeviceFilter, _baseGrabFlt, null);
if (hr < 0)
{
Marshal.ThrowExceptionForHR(hr);
}
// Get the IVideoWindow interface
VideoWindow = (ControlStreaming.IVideoWindow)GraphBuilder;
// Set the video window to be a child of the main window
var source = PresentationSource.FromVisual(PreviewWindow) as HwndSource;
hr = VideoWindow.put_Owner(source.Handle);
if (hr < 0)
{
Marshal.ThrowExceptionForHR(hr);
}
// Set video window style
hr = VideoWindow.put_WindowStyle(WS_CHILD | WS_CLIPCHILDREN | WS_CLIPSIBLINGS);
if (hr < 0)
{
Marshal.ThrowExceptionForHR(hr);
}
// Position video window in client rect of owner window
PreviewWindow.SizeChanged += OnPreviewWindowResize;
OnPreviewWindowResize(this, null);
// Make the video window visible, now that it is properly positioned
hr = VideoWindow.put_Visible(CoreStreaming.DsHlp.OATRUE);
if (hr < 0)
{
Marshal.ThrowExceptionForHR(hr);
}
IsPreviewRendered = true;
didSomething = true;
var media = new CoreStreaming.AMMediaType();
hr = SampGrabber.GetConnectedMediaType(media);
if (hr < 0)
{
Marshal.ThrowExceptionForHR(hr);
}
if ((media.formatType != Uuid.FormatType.VideoInfo) || (media.formatPtr == IntPtr.Zero))
{
throw new NotSupportedException("Unknown Grabber Media Format");
}
_videoInfoHeader = (EditStreaming.VideoInfoHeader)Marshal.PtrToStructure(media.formatPtr, typeof(EditStreaming.VideoInfoHeader));
Marshal.FreeCoTaskMem(media.formatPtr); media.formatPtr = IntPtr.Zero;
}
if (didSomething)
{
ActualGraphState = GraphState.Rendered;
}
}
/// <summary>
/// Completely tear down a filter graph and
/// release all associated resources.
/// </summary>
protected void DestroyGraph()
{
// Derender the graph (This will stop the graph
// and release preview window. It also destroys
// half of the graph which is unnecessary but
// harmless here.) (ignore errors)
try { DerenderGraph(); }
catch { }
// Update the state after derender because it
// depends on correct status. But we also want to
// update the state as early as possible in case
// of error.
ActualGraphState = GraphState.Null;
IsPreviewRendered = false;
// Remove filters from the graph
// This should be unnecessary but the Nvidia WDM
// video driver cannot be used by this application
// again unless we remove it. Ideally, we should
// simply enumerate all the filters in the graph
// and remove them. (ignore errors)
if (VideoCompressorFilter != null)
GraphBuilder.RemoveFilter(VideoCompressorFilter);
if (VideoDeviceFilter != null)
GraphBuilder.RemoveFilter(VideoDeviceFilter);
// Cleanup
if (GraphBuilder != null)
Marshal.ReleaseComObject(GraphBuilder); GraphBuilder = null;
if (CaptureGraphBuilder != null)
Marshal.ReleaseComObject(CaptureGraphBuilder); CaptureGraphBuilder = null;
if (VideoDeviceFilter != null)
Marshal.ReleaseComObject(VideoDeviceFilter); VideoDeviceFilter = null;
if (VideoCompressorFilter != null)
Marshal.ReleaseComObject(VideoCompressorFilter); VideoCompressorFilter = null;
// These are copies of graphBuilder
MediaControl = null;
VideoWindow = null;
// For unmanaged objects we haven't released explicitly
GC.Collect();
}
/// <summary>
/// Connects the filters of a previously created graph
/// (created by CreateGraph()). Once rendered the graph
/// is ready to be used. This method may also destroy
/// streams if we have streams we no longer want.
/// </summary>
protected void RenderGraph()
{
Guid cat;
Guid med;
int hr;
bool didSomething = false;
const int WS_CHILD = 0x40000000;
const int WS_CLIPCHILDREN = 0x02000000;
const int WS_CLIPSIBLINGS = 0x04000000;
// Stop the graph
if (MediaControl != null)
MediaControl.Stop();
// Create the graph if needed (group should already be created)
CreateGraph();
// Derender the graph if we have a capture or preview stream
// that we no longer want. We can't derender the capture and
// preview streams seperately.
// Notice the second case will leave a capture stream intact
// even if we no longer want it. This allows the user that is
// not using the preview to Stop() and Start() without
// rerendering the graph.
if (!WantPreviewRendered && IsPreviewRendered)
DerenderGraph();
// Render preview stream (only if necessary)
if (WantPreviewRendered && !IsPreviewRendered)
{
// Render preview (video -> renderer)
cat = Uuid.PinCategory.Preview;
med = Uuid.MediaType.Video;
hr = CaptureGraphBuilder.RenderStream(ref cat, ref med, VideoDeviceFilter, _baseGrabFlt, null);
if (hr < 0) Marshal.ThrowExceptionForHR(hr);
// Get the IVideoWindow interface
VideoWindow = (ControlStreaming.IVideoWindow)GraphBuilder;
// Set the video window to be a child of the main window
var source = PresentationSource.FromVisual(PreviewWindow) as HwndSource;
hr = VideoWindow.put_Owner(source.Handle);
if (hr < 0) Marshal.ThrowExceptionForHR(hr);
// Set video window style
hr = VideoWindow.put_WindowStyle(WS_CHILD | WS_CLIPCHILDREN | WS_CLIPSIBLINGS);
if (hr < 0) Marshal.ThrowExceptionForHR(hr);
// Position video window in client rect of owner window
PreviewWindow.SizeChanged += OnPreviewWindowResize;
OnPreviewWindowResize(this, null);
// Make the video window visible, now that it is properly positioned
hr = VideoWindow.put_Visible(CoreStreaming.DsHlp.OATRUE);
if (hr < 0) Marshal.ThrowExceptionForHR(hr);
IsPreviewRendered = true;
didSomething = true;
var media = new CoreStreaming.AMMediaType();
hr = SampGrabber.GetConnectedMediaType(media);
if (hr < 0)
Marshal.ThrowExceptionForHR(hr);
if ((media.formatType != Uuid.FormatType.VideoInfo) || (media.formatPtr == IntPtr.Zero))
throw new NotSupportedException("Unknown Grabber Media Format");
_videoInfoHeader = (EditStreaming.VideoInfoHeader)Marshal.PtrToStructure(media.formatPtr, typeof(EditStreaming.VideoInfoHeader));
Marshal.FreeCoTaskMem(media.formatPtr); media.formatPtr = IntPtr.Zero;
}
if (didSomething)
ActualGraphState = GraphState.Rendered;
}
/// <summary>
/// Disconnect and remove all filters except the device
/// and compressor filters. This is the opposite of
/// renderGraph(). Soem properties such as FrameRate
/// can only be set when the device output pins are not
/// connected.
/// </summary>
protected void DerenderGraph()
{
// Stop the graph if it is running (ignore errors)
if (MediaControl != null)
MediaControl.Stop();
// Free the preview window (ignore errors)
if (VideoWindow != null)
{
VideoWindow.put_Visible(CoreStreaming.DsHlp.OAFALSE);
VideoWindow.put_Owner(IntPtr.Zero);
VideoWindow = null;
}
// Remove the Resize event handler
if (PreviewWindow != null)
PreviewWindow.SizeChanged -= new SizeChangedEventHandler(OnPreviewWindowResize);
if ((int)ActualGraphState >= (int)GraphState.Rendered)
{
// Update the state
ActualGraphState = GraphState.Created;
IsPreviewRendered = false;
// Disconnect all filters downstream of the
// video and audio devices. If we have a compressor
// then disconnect it, but don't remove it
if (VideoDeviceFilter != null)
RemoveDownstream(VideoDeviceFilter, (VideoCompressor == null));
}
}
