MythArchive: update the encoding profiles to work with the current mythffmpeg

Refs #11299.

Signed-off-by: Stuart Auchterlonie <stuarta@squashedfrog.net>

(cherry picked from 5a0e83a20e8f75612b86fb56039b7803a11afd1b)
MythArchive: update mythburn.py to work with the updated encoding profiles

Refs #11299.

Signed-off-by: Stuart Auchterlonie <stuarta@squashedfrog.net>

(cherry picked from a784b93f1d1c6edbc0b47ac578def5d3275171a8)
MythArchive: update mythburn.py to work with the new mpeg2video codec name

Refs #11299.

Signed-off-by: Stuart Auchterlonie <stuarta@squashedfrog.net>

(cherry picked from 13c3035d1fed13a37c42d872b1f8dafb2e6f556f)
Make comparisons consistent

Refs #11299