The interfaces are contained in the type library and can be imported using #import<\/a> directive. An implementation of one or more of these interfaces will receive hook style calls corresponding to respective Filter Graph Manager<\/a> calls, system wide including in context of other applications.<\/p>\n A COM object may be registered as a hook object with Spy<\/em> and NoThreadSpy<\/em> COM classes under predefined registry keys:<\/p>\n Spy will instantiate the registered hook objects and forward them the calls it receive, before passing them to system Filter Graph Manager object. A hook object has an option to override default processing, including, for example, inserting its own filter in between. For example, IFilterGraph::Reconnect<\/a> call is implemented the following way:<\/p>\n Before passing the call to original Reconnect method, spy is iterating through associated hooks, passing them IFilterGraphConnectHook::OnReconnect<\/em> call. Setting bDefault<\/em> parameter to FALSE<\/em> will prevent spy from passing the call to original method.<\/p>\n Included BdaHooks<\/a> project shows a sample implementation of the hooking COM classes (note .rgs registration<\/a>).<\/p>\n Filter Graph Spy is compatible with all current Windows operating systems, 32-bit and 64-bit (x64<\/a>), in particular including:<\/p>\n NOTE: DirectShow Filter Graph Spy is NOT<\/span> suitable for production environment, it is NOT<\/span> licensed to be redistributed to be a part of production state software item.<\/p>\n Partial Visual C++ .NET 2008 source code is available from SVN<\/a>, release binary included (Win32<\/a>, x64<\/a>); installation instructions are in another post<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":" Today’s update for DirectShow Filter Graph Spy introduces 64-bit version (mind the beta state) and a mini-API for an external module to be involved into graph building process. Filter Graph Spy is offering three new interfaces that provide extensibility of the spy: IFilterGraphAddRemoveHook IFilterGraphConnectHook IFilterGraphStateControlHook The interfaces are contained in the type library and can… <\/p>\n![\"Registering](\"https:\/\/alax.info\/blog\/wp-content\/uploads\/2009\/11\/02-Image001-320x136.png\" "\\"Registering")
<\/a><\/p>\n\r\n
STDMETHOD(<\/span>Reconnect)<\/span>(<\/span>IPin*<\/span> pPin)<\/span> throw<\/span>(<\/span>)<\/span>\r\n{<\/span>\r\n _Z4(<\/span>atlTraceCOM,<\/span> 4<\/span>,<\/span> _T(<\/span>\"<\/span>...<\/span>\\n<\/span>\"<\/span>)<\/span>)<\/span>;<\/span>\r\n HOOK_PROLOG(<\/span>CFilterGraphConnectHookHost)<\/span>\r\n OnReconnect(<\/span>pT,<\/span> pPin,<\/span> &<\/span>bDefault)<\/span>;<\/span>\r\n HOOK_EPILOG(<\/span>)<\/span>\r\n return<\/span> m_pInnerFilterGraph2-<\/span>><\/span>Reconnect(<\/span>pPin)<\/span>;<\/span>\r\n}<\/span><\/pre>\n\n