[mythtv] FFmpeg 4.4.1 problems

[Scott Theisen]

My second try rebasing worked: 
https://github.com/ulmus-scott/FFmpeg/tree/rebase/4.4m

Note the following changes vs 
https://github.com/MythTV/FFmpeg/tree/release/4.4 :
two more cherry-picked commits from upstream

removed duplicated entry in libavcodec/codec_desc.c
fixed indentation in two other files

tweaked Klaas' commit message to not confuse GitHub: 
https://github.com/ulmus-scott/FFmpeg/commit/77526ccf1dbf62cab94f8b0522b7615a016f9314

dropped two commits and their reversions

Regards,
Scott