Bug#739079: transition: libav10

[anton@khirnov.net]

Hi,
(a libav developer responsible for most of the breaks here)

I do not think bringing back the CODEC_ID_* stuff is such a great idea.
The reasons are:

- keeping compatibility in this case requires a rather ugly hack (because in c++
  different enums are not compatible), which has to my knowledge broken at least
  one program (this is also the reason the change was made -- CODEC_ID is a very
  generic identifier, so there's a rather high chance of conflicts)
- experience tells us that the downstreams generally do not adapt until they
  have to, so this would just postpone the breakage for a time, we'd still have
  to deal with it eventually
- adapting to this specific change in Debian is a trivial replacement that can
  be done with sed (since only one libav version needs to be supported). Fixing
  downstreams that want to support older libav versions is a little more
  involved, but still no rocket science; I've already sent patches to a number
  of downstreams, but some are slow to respond, or want to support very old
  versions. If you don't mind carrying some patches until the downstreams fix
  their stuff, I can write Debian-specific patches that only work with latest
  Libav (jitsi comes to mind here, most other complex breakage should be fixed
  already)

Finally, I'm sorry that the changes are causing so much pain to our downstreams,
but I believe they are necessary and must be made sooner or later.

Regards
-- 
Anton Khirnov