[Xvid-devel] Patch for XVID MPEG-4 DirectShow/MediaFoundation filter

[Jerker Bäck]

Hi Edouard,

> My bad
OK, no problem

> ... xvid
> not going to work fine when forcing another calling convention during
> build. Sadly your patch doesn't address that :-)
I don't see that. To mark the exports as __cdecl would be consistent with
past and future builds of xvidcore. Even if someone took the trouble to
cream out some extra performance with a different calling convention, it
would present the same consistent interface to the outside world (__cdecl).

This is an improvement above the current implicit, unspoken fact that the
exports actually are __cdecl. We humans may be able to assume that, but the
compiler will be confused unless told exactly.

--------------------------------------------------------------

Here is another variant

#if defined(XVID_BUILD_DLL) && (defined(_WIN32) || defined(__CYGWIN__) || \
    defined(_MSC_VER))
#define XVID_IMPEXP             __declspec(dllexport)
#elif defined(XVID_BUILD_DLL) && (defined(__GNUC__) && (__GNUC__ >= 4))
#define XVID_IMPEXP             __attribute__ ((visibility ("default")))
#else
#define XVID_IMPEXP             extern
#endif
#if defined(_WIN32) || defined(_MSC_VER)
#define XVID_CALL               __cdecl
#else
#define XVID_CALL
#endif 


The GCC visibility is taken from:
http://gcc.gnu.org/wiki/Visibility
Note: I have no experience of how GCC visibility actually works (pitfalls or
special tweaks).

The apparently weird "|| defined(_MSC_VER)" is due to the fact that the MS
compiler may be used without the _WIN32 internal define (undefined for the
POSIX subsystem).

Regards
Jerker