[Ffmpeg-devel] Win32 unresolved external symbol
Wed Sep 7 17:02:51 CEST 2005
Michel Bardiaux wrote:
> Martin Boehme wrote:
>> Michel Bardiaux wrote:
>> [on the subject of linking static FFmpeg libs compiled with MinGW into
>> an MSVC app]
>>> You have to add libgcc.a to the build (mine is in
>> Is this really safe? I seem to remember there was a discussion about
>> this a while back, and the conclusion was that while linking to
>> libgcc.a works, it is a Bad Thing in some way or another, and that the
>> libgcc.a runtime doesn't play well in an MSVC environment...
> Its only a very small part of the gcc runtime, the one containing
> functions called because the call is generated by the compiler for some
> kinds of math operations on types not supported by the hardware.
Found a description here:
Most of that shouldn't be a problem -- probably with the exception of
the exception handling routines (no pun intended). Since ffmpeg is pure
C, it should never need those, but in a C++ environment, it could play
havoc -- maybe that's the reason why linking to libgcc is "considered
BTW, sorry for the delay in replying. I was hoping someone would jump in
with some definitive info... unfortunately, no one did...
>> IIRC, the gist was that there was no good way to link a MinGW compiled
>> static lib into an MSVC app and the only "clean" solution is link
>> against DLLs.
> Good call, the OP did not actually specify whether he linked against
> static or DLL.
I'm pretty sure it would have had to be static... linking against a DLL
shouldn't produce those kinds of errors...?
>> All of this is "IIRC" -- can someone jump in to clarify? I don't want
>> to start any rumours here... from all I know, the libgcc.a solution
>> may be completely safe...
> And if its not and MSVC support is required, then --enable-shared should
> be mandatory. OK?
Right. Only question that remains open is... is linking against libgcc OK?
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