[FFmpeg-devel] Upgrade Trouble

Uoti Urpala uoti.urpala
Sun Dec 6 10:50:21 CET 2009

On Sat, 2009-12-05 at 17:55 +0100, Michael Niedermayer wrote:
> On Sat, Dec 05, 2009 at 01:41:59PM +0100, Reinhard Tartler wrote:
> > Michael Niedermayer <michaelni at gmx.at> writes:
> > > If we do have to use versioning, then it seems changing libavutil to use
> > > it would solve the problem at hand, that also would avoid any problems
> > > with lavc->lavf moves for the moment.
> > 
> > Why just libavutil, and not each and every library in FFmpeg?
> Because it seemed that this is the minimal change that solves the
> problem and because that way the lavc->lavf code move issue does not
> arrise
> iam not opposed to have versioning added to all if doing so has an
> advantage, ATM though i just see a small disadvantage in it.

As I said in an earlier mail introducing symbol versioning requires
rebuilding depending applications/libraries, and it's better to do that
for all FFmpeg libraries in one go. Symbol versioning _will_ be needed
for lavc/lavf too at latest at the next version bump (as there are other
libraries depending on them), and introducing the new versions smoothly
requires that everything has been built with versioning support _before_
the new lavc/lavf versions appear.

The lavf->lavc symbol move makes it harder to retroactively add symbol
versioning to previous lavf versions, but leaving lavf in _current_
FFmpeg unversioned does not help with that in any way. It'd only have an
effect if another symbol move was still done the same way in the future.

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