.mdat

MP4 media data atom holding the raw audio and video samples of an MP4 file

Not a file (scheme/atom)

Format facts

MIME type: application/x-mp4-mdat
Apple UTI: custom
Stock Quick Look: no stock preview
Planned approach (census): not-a-file
Icon hint: generic-icon
Prevalence: rare

Renderer note (from the census)

skip mdat atom, extract from moov/stbl

Gotchas: actual media data