FTBFS against ffmpeg 4

In the ffmpeg4 transition, no-change-rebuild of transcode FTBFS

Ref: https://launchpad.net/ubuntu/+source/transcode/3:1.1.7-9ubuntu3

Patches for fixing build with ffmpeg 4 exist:

e.g. for arch: https://git.archlinux.org/svntogit/community.git/tree/trunk?h=packages/transcode

That example however fails to apply cleanly, and I am not sure how to correctly resolve the conflicts without perhaps breaking compilation or function.

This FTBFS is one of the current blocker in the ffmpeg transition.

Extra info:

reverse-depends transcode
Reverse-Recommends
==================
* k3b
* xjadeo

Reverse-Depends
===============
* dvdrip
* ripmake
* subtitleripper
* transcode-dbg

reverse-depends dvdrip
No reverse dependencies found

reverse-depends ripmake
No reverse dependencies found

reverse-depends subtitleripper
Reverse-Recommends
==================
* dvdrip