MOV (QuickTime)

MOV is the format iPhones record video into, the format the macOS screenshot tool saves screen recordings as, the format QuickTime Player edits natively. Under the hood it’s the same ISO Base Media File Format (ISOBMFF) as MP4 — and Tracemute uses literally the same handler for both.

What it carries

Everything MP4 carries (see the MP4 page for the full breakdown) plus a stronger lean toward modern Apple metadata patterns:

• udta with QuickTime ©* atoms (©xyz GPS, ©day creation, ©mod model, ©too software).
• moov/meta/keys+ilst with com.apple.quicktime.* namespace keys. Modern iPhone MOV files put everything here, including:
  • com.apple.quicktime.location.ISO6709 — GPS coordinates as an ISO 6709 string
  • com.apple.quicktime.location.accuracy.horizontal — typed 32-bit float, in metres
  • com.apple.quicktime.make / .model / .software — device fingerprints
  • com.apple.quicktime.creationdate — capture time with timezone
  • com.apple.quicktime.content.identifier — the Live Photos pairing UUID

What’s unique

The Apple-specific lean: where an Android-recorded MP4 might use ©* atoms in udta, the equivalent iPhone-recorded MOV uses keys+ilst exclusively for the same data. iOS doesn’t write ©xyz GPS the way QuickTime Player did — it writes com.apple.quicktime.location.ISO6709 in ilst, with a typed-data box that carries the UTF-8 string and a type indicator of 1 (text).

If you’ve ever AirDropped a video and seen .mov arrive, you have a file that almost certainly has GPS + camera + Apple AssetIdentifier in keys+ilst. The HEIC photo it was paired with (if it was a Live Photo) has the same identifier in its MakerNote — proving the pair.

What Tracemute does

Same handler as MP4. The dispatch table in src/workers/media.worker.ts routes both video/mp4 and video/quicktime to the same stripMp4 function. Free-atom strategy: rewrite udta / meta / uuid boxes to type free, zero the body, leave the sample-table offsets and mdat payload untouched.

Before stripping, the ilst parser maps known Apple keys into typed dossier fields so the user sees GPS (Apple ilst) with the actual lat/lon, Model (Apple ilst) with the device name, and so on — instead of “iTunes-style metadata present” which would be useless context.

What survives

Same as MP4: mvhd / tkhd / mdhd timestamps (decoder-required), the full video and audio sample streams.