[FFmpeg-devel] Shared libraries major version

[Stefano Sabatini]

On date Saturday 2013-11-30 13:55:15 +0100, Nicolas George encoded:
> Hi.
> 
> There is a compatibility problem with the shared libraries major versions,
> at least in the ELF world.
[...]
> Still, there are ways of mitigating the problem. Mostly, they amount to
> bumping immediately lavfi's SONAME, and optionally providing a stub library
> for compatibility.
> 
> The obvious way is to bump lavfi to 4, of course. But in that case, we can
> kiss compatibility with the fork goodbye when they bump.
> 
> Second solution: bump lavfi to a completely different numbering, such as
> 101. Still a lot of problems for applications that have
> LIBAVFILTER_VERSION_MAJOR ifdefry.
> 
> Third solution: since the problem is only with ELF shared libraries, bump
> only the SONAME of the ELF shared library: libavfilter.so.3-55 for example.
> 
> (It could be taken to the next level: include all the dependencies versions
> in all the SONAMEs; that would mean something like
> libavfilter.so.3-55-55-0-0-52-52. That is rather ugly, and probably not
> necessary.)
> 
> Fourth solution: kill the issue completely by merging all libraries
> together. I realize some people here will consider it a troll, and I
> apologize for that, but I personally think this would be the best move, even
> without the SONAME issue.
> 
> I hope I have summarized the issue clearly enough and not made too many
> mistakes.

Thanks for the detailed report. Since the problem was generated in the
fork, maybe they are aware of the problem or we can notice them about
it (don't know if someone is still reading this mailing list).

Clean solution is to bump lavfi major version as soon as possible, and
keep broken what is broken. I don't like very much more complex
versioning schemes.

About the big library merge, what are the technical advantages of that
solution? Would it be possible to generate a libffmpeg.so library *as
alternative* to the current split library set (enabled at
configure-time)?
-- 
FFmpeg = Friendly Fundamentalist Minimal Portable Esoteric Guru