[FFmpeg-devel] [RFC] FFmpeg "developers conference"

[Uoti Urpala]

On Tue, 2007-06-19 at 13:00 +0200, Luca Barbato wrote:
> What prevents us from moving to git currently?

I think the biggest practical issues would be the svn extern usages. Not
only FFmpeg's use of swscale from MPlayer, but MPlayer's use of FFmpeg
directories. FFmpeg and MPlayer probably need to move to git at the same
time. Moving FFmpeg only would not be completely impossible but doesn't
seem like a good idea because:
- moving FFmpeg would require significant changes to MPlayer setup anyway
- moving FFmpeg already makes git necessary for MPlayer development
- integrating the handling of FFmpeg git directories is harder from
  subversion than from git.

AFAIK git's subproject support is meant to solve use cases like this,
but isn't yet complete (I haven't checked the current status). Even
without subproject support it's possible to set up a build with two
repositories, but it's harder and might cause problems for "ordinary"
users.

>  I can migrate swscale to
> ffmpeg quite easly if that was the problem, the recipe is simple:

but not without problems...

> in mplayer make a branch and remove everything that isn't libswscale,
> prune to clean up and commit this change.

prune doesn't actually do anything here (no object has become
unreachable).

> in ffmpeg make a branch and git pull the libswscale-only branch from the
> mplayer repo.
> 
> Commit the change.
> 
> That's all, the story is preserved and ffmpeg has a coherent tree.

I think this would make the FFmpeg history about 3.5 times as large in
bytes, as it'd contain the complete MPlayer history. You also could not
build checked-out versions from before the merge as they would not
contain swscale.