When set to NORMAL (default), the deinterlacer does not convert frames
that are tagged in metadata as progressive. It will only convert those that
are tagged as some other type. - When set to FORCE_ALL_FRAMES, the
deinterlacer converts every frame to progressive - even those that are
already tagged as progressive. Turn Force mode on only if there is a good
chance that the metadata has tagged frames as progressive when they are not
progressive. Do not turn on otherwise; processing frames that are already
progressive into progressive will probably result in lower quality video.