A while ago, you posted code in response to this post.
https://stackoverflow.com/questions/42946608/media-foundation-custom-mixer-mft-getting-error-mf-e-cannot-create-sink?noredirect=1&lq=1
I compile that code and there were classes that were not included. Can you post the complete class?
>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetStreamOutputRect(unsigned long,struct MFVideoNormalizedRect *)" (?GetStreamOutputRect@CCustomVideoMixer@@UEAAJKPEAUMFVideoNormalizedRect@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetStreamZOrder(unsigned long,unsigned long *)" (?GetStreamZOrder@CCustomVideoMixer@@UEAAJKPEAK@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetStreamOutputRect(unsigned long,struct MFVideoNormalizedRect const *)" (?SetStreamOutputRect@CCustomVideoMixer@@UEAAJKPEBUMFVideoNormalizedRect@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetStreamZOrder(unsigned long,unsigned long)" (?SetStreamZOrder@CCustomVideoMixer@@UEAAJKK@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetAvailableVideoProcessorModes(unsigned int *,struct _GUID * *)" (?GetAvailableVideoProcessorModes@CCustomVideoMixer@@UEAAJPEAIPEAPEAU_GUID@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetBackgroundColor(unsigned long *)" (?GetBackgroundColor@CCustomVideoMixer@@UEAAJPEAK@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetFilteringRange(unsigned long,struct _DXVA2_ValueRange *)" (?GetFilteringRange@CCustomVideoMixer@@UEAAJKPEAU_DXVA2_ValueRange@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetFilteringValue(unsigned long,struct _DXVA2_Fixed32 *)" (?GetFilteringValue@CCustomVideoMixer@@UEAAJKPEAU_DXVA2_Fixed32@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetProcAmpRange(unsigned long,struct _DXVA2_ValueRange *)" (?GetProcAmpRange@CCustomVideoMixer@@UEAAJKPEAU_DXVA2_ValueRange@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetProcAmpValues(unsigned long,struct _DXVA2_ProcAmpValues *)" (?GetProcAmpValues@CCustomVideoMixer@@UEAAJKPEAU_DXVA2_ProcAmpValues@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetVideoProcessorCaps(struct _GUID *,struct _DXVA2_VideoProcessorCaps *)" (?GetVideoProcessorCaps@CCustomVideoMixer@@UEAAJPEAU_GUID@@PEAU_DXVA2_VideoProcessorCaps@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetVideoProcessorMode(struct _GUID *)" (?GetVideoProcessorMode@CCustomVideoMixer@@UEAAJPEAU_GUID@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetBackgroundColor(unsigned long)" (?SetBackgroundColor@CCustomVideoMixer@@UEAAJK@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetFilteringValue(unsigned long,struct _DXVA2_Fixed32 *)" (?SetFilteringValue@CCustomVideoMixer@@UEAAJKPEAU_DXVA2_Fixed32@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetProcAmpValues(unsigned long,struct _DXVA2_ProcAmpValues *)" (?SetProcAmpValues@CCustomVideoMixer@@UEAAJKPEAU_DXVA2_ProcAmpValues@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetVideoProcessorMode(struct _GUID *)" (?SetVideoProcessorMode@CCustomVideoMixer@@UEAAJPEAU_GUID@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::Compare(struct IMFAttributes *,enum _MF_ATTRIBUTES_MATCH_TYPE,int *)" (?Compare@CCustomVideoMixer@@UEAAJPEAUIMFAttributes@@W4_MF_ATTRIBUTES_MATCH_TYPE@@PEAH@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::CompareItem(struct _GUID const &,struct tagPROPVARIANT const &,int *)" (?CompareItem@CCustomVideoMixer@@UEAAJAEBU_GUID@@AEBUtagPROPVARIANT@@PEAH@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::CopyAllItems(struct IMFAttributes *)" (?CopyAllItems@CCustomVideoMixer@@UEAAJPEAUIMFAttributes@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::DeleteAllItems(void)" (?DeleteAllItems@CCustomVideoMixer@@UEAAJXZ) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::DeleteItem(struct _GUID const &)" (?DeleteItem@CCustomVideoMixer@@UEAAJAEBU_GUID@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetAllocatedBlob(struct _GUID const &,unsigned char * *,unsigned int *)" (?GetAllocatedBlob@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEAPEAEPEAI@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetAllocatedString(struct _GUID const &,wchar_t * *,unsigned int *)" (?GetAllocatedString@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEAPEA_WPEAI@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetBlob(struct _GUID const &,unsigned char *,unsigned int,unsigned int *)" (?GetBlob@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEAEIPEAI@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetBlobSize(struct _GUID const &,unsigned int *)" (?GetBlobSize@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEAI@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetCount(unsigned int *)" (?GetCount@CCustomVideoMixer@@UEAAJPEAI@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetDouble(struct _GUID const &,double *)" (?GetDouble@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEAN@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetGUID(struct _GUID const &,struct _GUID *)" (?GetGUID@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEAU2@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetItem(struct _GUID const &,struct tagPROPVARIANT *)" (?GetItem@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEAUtagPROPVARIANT@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetItemByIndex(unsigned int,struct _GUID *,struct tagPROPVARIANT *)" (?GetItemByIndex@CCustomVideoMixer@@UEAAJIPEAU_GUID@@PEAUtagPROPVARIANT@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetItemType(struct _GUID const &,enum _MF_ATTRIBUTE_TYPE *)" (?GetItemType@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEAW4_MF_ATTRIBUTE_TYPE@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetString(struct _GUID const &,wchar_t *,unsigned int,unsigned int *)" (?GetString@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEA_WIPEAI@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetStringLength(struct _GUID const &,unsigned int *)" (?GetStringLength@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEAI@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetUINT64(struct _GUID const &,unsigned __int64 *)" (?GetUINT64@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEA_K@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetUnknown(struct _GUID const &,struct _GUID const &,void * *)" (?GetUnknown@CCustomVideoMixer@@UEAAJAEBU_GUID@@0PEAPEAX@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::LockStore(void)" (?LockStore@CCustomVideoMixer@@UEAAJXZ) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetDouble(struct _GUID const &,double)" (?SetDouble@CCustomVideoMixer@@UEAAJAEBU_GUID@@N@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetGUID(struct _GUID const &,struct _GUID const &)" (?SetGUID@CCustomVideoMixer@@UEAAJAEBU_GUID@@0@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetItem(struct _GUID const &,struct tagPROPVARIANT const &)" (?SetItem@CCustomVideoMixer@@UEAAJAEBU_GUID@@AEBUtagPROPVARIANT@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetString(struct _GUID const &,wchar_t const *)" (?SetString@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEB_W@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetUINT32(struct _GUID const &,unsigned int)" (?SetUINT32@CCustomVideoMixer@@UEAAJAEBU_GUID@@I@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetUINT64(struct _GUID const &,unsigned __int64)" (?SetUINT64@CCustomVideoMixer@@UEAAJAEBU_GUID@@_K@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetUnknown(struct _GUID const &,struct IUnknown *)" (?SetUnknown@CCustomVideoMixer@@UEAAJAEBU_GUID@@PEAUIUnknown@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::UnlockStore(void)" (?UnlockStore@CCustomVideoMixer@@UEAAJXZ) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::ClearAlphaBitmap(void)" (?ClearAlphaBitmap@CCustomVideoMixer@@UEAAJXZ) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::GetAlphaBitmapParameters(struct MFVideoAlphaBitmapParams *)" (?GetAlphaBitmapParameters@CCustomVideoMixer@@UEAAJPEAUMFVideoAlphaBitmapParams@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::SetAlphaBitmap(struct MFVideoAlphaBitmap const *)" (?SetAlphaBitmap@CCustomVideoMixer@@UEAAJPEBUMFVideoAlphaBitmap@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::UpdateAlphaBitmapParameters(struct MFVideoAlphaBitmapParams const *)" (?UpdateAlphaBitmapParameters@CCustomVideoMixer@@UEAAJPEBUMFVideoAlphaBitmapParams@@@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "public: virtual long __cdecl CCustomVideoMixer::MapOutputCoordinateToInputStream(float,float,unsigned long,unsigned long,float *,float *)" (?MapOutputCoordinateToInputStream@CCustomVideoMixer@@UEAAJMMKKPEAM0@Z) 1>CustomVideoMixer.obj : error LNK2001: unresolved external symbol "private: static long volatile ClassFactory::m_serverLocks" (?m_serverLocks@ClassFactory@@0JC)