.mpg

MPEG-1 or MPEG-2 video stream, the ISO standard format used on DVDs and early digital video

Handled by macOS itself

Format facts

MIME type: video/mpeg
Apple UTI: public.mpeg
Stock Quick Look: no stock preview
Planned approach (census): native-sufficient
Icon hint: plays
Prevalence: universal

Renderer note (from the census)

macOS plays MPEG natively

Gotchas: legacy standard