Backport of "video-converter: Don't upsample invalid lines" into 1.18
Backport of !1043 (merged) "video-converter: Don't upsample invalid lines".
Commits:
- 1517b704 video-converter: Don't upsample/downsample/dither invalid lines
Backport of !1043 (merged) "video-converter: Don't upsample invalid lines".
Commits: