The DLL file has no error retrieving function. The called function returns with the error code (int). The BiVision.ocx will return the following error codes:
Error Code number
1
NO_FILTER_ERROR
No error
-1
ERROR_NO_BIDLGS
BiDlgs.dll does not exist
-2
ERROR_NO_BIIMAGE
BiImage.dll does not exist
-3
ERROR_INVALIDPARAMETER
Invalid parameter
-4
ERROR_DUPLICATE
Error duplicate DIB
-5
ERROR_DEMO
Error demo version