Jason R. Coombs schrieb: > I'm trying to port VideoCapture from an extension module to a pure-python > module based on comtypes. > > I've started by converting the following: > > hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL, CLSCTX_INPROC, > > IID_ICaptureGraphBuilder2, (void > **)&self->ob_pBuilder); > > hr = self->ob_pBuilder->SetFiltergraph(self->ob_pGraph); > > > to the following using comtypes: > > self.graph_builder = > CreateObject(CLSID_CaptureGraphBuilder2, CLSCTX_INPROC) > > self.graph_builder.SetFiltergraph(self.filter_graph) > > The problem I encounter is the creation of the graph_builder doesn't have > any type information, so SetFiltergraph fails. It has no interface, so gets > created as an IUnknown. > > I can find in the SDK the .idl that contains the definition for > ICaptureGraphBuilder2 (axextend.idl) and other interfaces I'll need. The > docs indicate that the best way to generate the Interface classes is to > create a temporary type lib from the IDL. Can you describe or point me to a > description of how one would go about creating a temporary type lib? Is it > possible that there's already a type lib created for some other purpose > lying around, and if so, how would I locate it?
Often, this has already been done. A little googling found this page which has a DirectShow.tlb type library: http://www.kohsuke.org/dotnet/directshowTypelib/ And it seems to work: Python 2.5.4 (r254:67916, Dec 23 2008, 15:10:54) [MSC v.1310 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> from comtypes.client import GetModule >>> GetModule("DirectShow.tlb") # Generating comtypes.gen._24BC6711_3881_420F_8299_34DA1026D31E_0_1_0 # Generating comtypes.gen._00020430_0000_0000_C000_000000000046_0_2_0 # Generating comtypes.gen.stdole # Generating comtypes.gen.DirectShowLib <module 'comtypes.gen.DirectShowLib' from 'comtypes\gen\_24BC6711_3881_420F_8299_34DA1026D31E_0_1_0.py'> >>> from comtypes.client import CreateObject >>> from comtypes.gen import DirectShowLib >>> builder = CreateObject(DirectShowLib.CaptureGraphBuilder2) >>> print builder <POINTER(ICaptureGraphBuilder2) ptr=0x927294 at a939e0> >>> builder.SetFilterGraph <bound method POINTER(ICaptureGraphBuilder2).SetFiltergraph of <POINTER(ICaptureGraphBuilder2) ptr=0x927294 at a939e0>> >>> help(builder.SetFilterGraph) Help on method SetFiltergraph in module ctypes: SetFiltergraph(...) method of comtypes.POINTER(ICaptureGraphBuilder2) instance >>> If you really want to compile your own type library, here's a simple idl file that should get you started. I constructed this by little experimentation: """ import "oaidl.idl"; import "ocidl.idl"; import "axcore.idl"; interface ICreateDevEnum; import "axextend.idl"; [ // TODO: Use a real clsid and helpstring uuid(00000000-0000-0000-0000-000000000000), version(1.0), helpstring("Type Library") ] library MyTypeLib { interface ICaptureGraphBuilder2; // TODO: Add more interfaces from axextend.idl that we need } """ Thomas ------------------------------------------------------------------------------ Register Now for Creativity and Technology (CaT), June 3rd, NYC. CaT is a gathering of tech-side developers & brand creativity professionals. Meet the minds behind Google Creative Lab, Visual Complexity, Processing, & iPhoneDevCamp as they present alongside digital heavyweights like Barbarian Group, R/GA, & Big Spaceship. http://p.sf.net/sfu/creativitycat-com _______________________________________________ comtypes-users mailing list comtypes-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/comtypes-users
