Video · high-capacity exFAT card
long 4K MP4: recover after an interrupted recording
What can I do with multi-gigabyte 4K MP4 clips after a recording interruption?
Short answer
Usually the end of a long take is what is at risk: if power failed, the final chapter may lack its moov index while earlier chapters, often split at 4 GB, are complete. Remove the card and keep an untouched copy. Check which chapters play, then repair only the last one on a copy.
The situation
multi-gigabyte 4K MP4 clips is missing, too short or unreadable after power loss, a card error or an unsafe stop.
With a long recording it is almost always the end that suffers. Everything the camera wrote and closed before the interruption is fine; the take that was still running when the power went lacks its closing index and will not open.
01 / Diagnose
Work out what actually disappeared
Cameras that split long recordings write each chapter, close it and start the next, so earlier chapters already carry a complete moov box. The final chapter is the one that was open when the battery died or the card faulted, and it consists of picture data with no index describing it.
The payload may have been written before duration fields, indexes, directory entries or closing structures were committed. For long 4K MP4, this matters because large clips occupy many clusters and face a higher chance of fragmentation or partial overwriting
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 the card and copy every chapter file off it before attempting anything else.
- 2
Open each chapter in turn and find out which ones already play; usually only the last one is unusable.
- 3
Use one of the intact chapters as the reference for repairing the broken one, because it carries identical recording settings.
- 4
Repair only the copy, then join the repaired final chapter to the intact ones in your editing software.
Do not let the camera fix the card, and do not overwrite the broken chapter with a repair attempt. Deleting the intact chapters to save space is a bad idea too, since one of them is the reference a repair tool needs.
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.
Rebuilding the index of the unfinished chapter is repair work. File Recovery Hero recovers deleted or lost files from exFAT, NTFS and FAT media read-only and does not mend individual damaged files, so use a repair tool on a copy; frames never written stay missing.
04 / Verify
Check the recovered content, not just its name
The repaired final chapter should report a duration matching the seconds between the last chapter break and the moment power failed, and it should play up to that cut without stalling. Joined together, the chapters must run as one continuous shot with no jump at the seams.
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 high-capacity exFAT card be recovered in this situation?+
With a long recording it is almost always the end that suffers. Everything the camera wrote and closed before the interruption is fine; the take that was still running when the power went lacks its closing index and will not open. The result still depends on what remains readable on the source.
What should I avoid before scanning?+
Do not let the camera fix the card, and do not overwrite the broken chapter with a repair attempt.
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 final chapter should report a duration matching the seconds between the last chapter break and the moment power failed, and it should play up to that cut without stalling.