Cam Alarm 2.0 - Alarm system run from a web camera

namespace dshow.Core
{
	using System;
	using System.Runtime.InteropServices;

	// IVideoFrameStep interface
	//
	[ComImport,
	Guid("E46A9787-2B71-444D-A4B5-1FAB7B708D6A"),
	InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
	public interface IVideoFrameStep
	{
		// Causes the filter graph to step forward by the
		// specified number of frames
		[PreserveSig]
		int Step(
			int dwFrames,
			[In, MarshalAs(UnmanagedType.IUnknown)] object pStepObject);

		// Determines the stepping capabilities of the specified filter
		[PreserveSig]
		int CanStep(
			int bMultiple,
			[In, MarshalAs(UnmanagedType.IUnknown)] object pStepObject);

		// Cancels the previous step operation
		[PreserveSig]
		int CancelStep();
	}
}