HI everyone, i am using some DirectShow classes adn my program do the following: 1. in Debug Mode: i link strmbasd.lib and the program work properly 2. in release Mode : i link strmbase.lib but the program gives the following Errors : - Error 38 error LNK2001: unresolved external symbol "public: virtual long __stdcall CBaseRenderer::FindPin(wchar_t const *,struct IPin * *)" (?FindPin@CBaseRenderer@@UAGJPB_WPAPAUIPin@@@Z) DShowTextures.obj Player - 23 - 3 - 08 - Error 39 error LNK2001: unresolved external symbol "public: virtual long __stdcall CBaseFilter::QueryVendorInfo(wchar_t * *)" (?QueryVendorInfo@CBaseFilter@@UAGJPAPA_W@Z) DShowTextures.obj Player - 23 - 3 - 08 - Error 40 error LNK2001: unresolved external symbol "public: virtual long __stdcall CBaseVideoRenderer::JoinFilterGraph(struct IFilterGraph *,wchar_t const *)" (?JoinFilterGraph@CBaseVideoRenderer@@UAGJPAUIFilterGraph@@PB_W@Z) DShowTextures.obj Player - 23 - 3 - 08 can anybody tell me what's the problem, what do i do wrong ? Thanks in advance, Sawsan A.Emam

Have a look at the "additional dependancies" section in your linker settings and see what's different between debug and release.

Alternatively, does it work if you include the source for all the base classes in your project (Although that's not an ideal solution)?