Timo Rothenpieler (12023-12-08):
> Is mixing the libraries really a scenario we need to care about/support?

No. We should merge all the libraries into a single libffmpeg.so. Having
separate libraries brings us no end of hassle and drawbacks, starting
with all the avpriv symbols and backward compatibility layers, and the
benefits it brings could be reached in simpler and more efficient ways.

But anytime I brought it up, the same naysayers would object, but when I
ask what precise benefit they think the current situation brings, with
the intent of explaining how it can be done better differently (I do not
bring that half-backed, I have thought about it beforehand) or in some
case explaining that no, this is not a benefit because linking does not
work like that. And then the naysayers would whine that I am making too
much a fuss.

Barring merging all libraries into a single libffmpeg.so, have configure
compute AV_LIBRARY_SIGNATURE as a 64 bits hash of the version and
configuration, then have in version.h of each library:

#define avsmth_version_check_signature() \
  avsmth_version_check_signature_ ## AV_LIBRARY_SIGNATURE()

then have avsmth_version_check_signature() in each library call the ones
in the library it depends on, and core functions like *register_all()
call it. Then if the libraries are mixed at run time it will produce an
error message by the linker that can be searched on the web.

Regards,

-- 
  Nicolas George