Bug#863754: Incorrect package description (and name) of gst-libav1.0 / gstreamer1.0-libav: It's ffmpeg, not libav

[Daniel van Vugt]

Package: gstreamer1.0-libav
Version: 1.12.0-1

Incorrect package description (and name) of gst-libav1.0 / 
gstreamer1.0-libav: Refers to libav even though Ubuntu/Debian uses 
FFmpeg instead of libav:

------------
Package: gstreamer1.0-libav
...
Description: libav plugin for GStreamer
...
  http://www.libav.org/
  http://gstreamer.freedesktop.org/
  http://gstreamer.freedesktop.org/modules/gst-libav.html
------------

They are distinct projects:
http://libav.org/ <-- Was used in the past
https://ffmpeg.org/ <-- Now used by Ubuntu and Debian

More history:
https://en.wikipedia.org/wiki/Libav#History

The incorrect wording appears to be directly inherited from upstream:
https://packages.debian.org/experimental/gstreamer1.0-libav

So the package description and names in Ubuntu and in Debian appear to 
be wrong. They should replace 'libav' with 'ffmpeg' (although 
confusingly both provide 'libav*' libraries).

Short term I think it makes sense to just fix up the Description text. 
Longer term if libav dies off in favor of ffmpeg and/or no one intends 
to ever switch back to libav from ffmpeg again then the package and 
projects should rename to s/libav/ffmpeg/g.

Downstream bug report: http://bugs.launchpad.net/bugs/1694409