Video · dual-slot exFAT camera media
relay-recorded MP4: recover after an interrupted recording
What can I do with clips split across two card slots after a recording interruption?
Short answer
Check the second card first: if power failed after the slot switch, the part on the first card is usually complete, and only the continuation on the second card lacks its moov index. Copy both cards, then repair just the unfinished part on a copy with a reference clip from the same camera and slot setting.
The situation
clips split across two card slots is missing, too short or unreadable after power loss, a card error or an unsafe stop.
Look at the second card first. When power failed after the relay switch, the part on the first card had already been closed properly and only the continuation was left open without its moov index. That splits the work: one half is a straight copy, the other a repair.
01 / Diagnose
Work out what actually disappeared
Relay recording closes the file on the full card before writing on to the next one, so that part carries a complete index. The clip that was still being written when the power dropped holds payload but no closing structures, which is why it reports zero length, refuses to open, or is missing from the folder altogether.
The payload may have been written before duration fields, indexes, directory entries or closing structures were committed. For relay-recorded MP4, this matters because a recording may continue on another card while numbering and metadata span both slots
Check the last known path, trash and backups without writing to the original device.
02 / Protect the source
Preserve the best recovery chance
- 1
Power the camera down, remove both cards and refuse any repair offer when a card is next put into a device.
- 2
Copy the closed part from the first card and confirm that it plays from beginning to end before touching anything else.
- 3
Image the second card or copy the unfinished clip, then run every repair attempt on that duplicate only.
- 4
Rebuild the container with a reference clip from the same camera, mode and relay setting, keeping the original file untouched.
Do not let the camera fix the unfinished clip on the card itself, and do not aim the repair tool at your only copy. Carrying on with the shoot on either card before both parts are secured can bury the continuation under new recordings.
03 / Choose the method
Match the tool to the source
For stable, readable exFAT, NTFS and FAT16/FAT32 or uncompressed IMG, DD, RAW and BIN images.
Unconfirmed exports are marked .UNVERIFIED.
File Recovery Hero reads the exFAT cards read-only and recovers files missing from the directory; it does not write a new moov index into an unfinished MP4, so container repair stays a separate tool working on a copy. A card that fails physically belongs in a laboratory.
04 / Verify
Check the recovered content, not just its name
The repaired continuation should start exactly where the closed part ends and run to the moment the power dropped. The combined duration will be shorter than planned, which is expected, but the seam has to be clean: no repeated frames, no silence, no drift between picture and sound.
Keep the source until two verified copies exist. One working preview is not enough.
Sources and technical references
FAQ
Questions about this recovery case
Can dual-slot exFAT camera media be recovered in this situation?+
Look at the second card first. When power failed after the relay switch, the part on the first card had already been closed properly and only the continuation was left open without its moov index. That splits the work: one half is a straight copy, the other a repair. The result still depends on what remains readable on the source.
What should I avoid before scanning?+
Do not let the camera fix the unfinished clip on the card itself, and do not aim the repair tool at your only copy.
Does scanning write to my memory card?+
Your memory card is only read. Nothing is saved to it.
How do I know whether the result is complete?+
The repaired continuation should start exactly where the closed part ends and run to the moment the power dropped.