Cameras · Canon MP4 recording card
Canon MP4 unfinalized after battery loss
Can a Canon MP4 be recovered after the battery died while recording?
Short answer
Often in part: the recorded frames can reach the card even though the camera never wrote the closing metadata or committed the directory entry. Recover the best MP4 extent to another drive first and leave that result untouched. Run any repair tool only on a second copy, then play the repaired clip through to its last second.
The situation
The final clip is absent or unplayable after sudden camera power loss.
The frames written before the power cut are usually on the card; what is missing is the closing step. An MP4 needs its moov section, written when recording stops, plus a committed directory entry. Without those the clip exists as data but not yet as a playable file.
01 / Diagnose
Work out what actually disappeared
While recording, the camera streams picture and sound into the mdat area and holds the index in memory, writing the moov section only when you press stop. A battery failure ends that sequence: the media data sits on the card, the moov is absent, and the directory entry may never have received the final size, so the clip looks short or invisible.
The MP4 may contain media data without final metadata, or its directory entry may not have been committed.
Check the last known path, trash and backups without writing to the original device.
02 / Protect the source
Preserve the best recovery chance
- 1
Leave the card out of the camera; a body that boots with it inserted can rebuild management files over the unfinished clip.
- 2
Scan the exFAT volume read-only for MP4 and pick the candidate whose size best fits the length you were recording.
- 3
Export that extent to another drive and keep the exported file as an untouched master copy.
- 4
Make a second copy and let a repair tool rebuild the index there, using a complete clip from the same camera as reference.
Do not run a repair tool against the card or against your only copy, and do not let the camera attempt its own recovery routine first. A failed repair on the single recovered extent leaves nothing to make a second attempt with.
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 recovers the MP4 extent from a readable card; it neither rebuilds a missing moov section nor repairs a damaged individual file, which calls for a separate repair tool working on a copy. Physically failing cards belong in a laboratory.
04 / Verify
Check the recovered content, not just its name
The repaired copy is good when it plays from the first second to the last, when picture and audio stay in sync right to the end, and when the duration is close to the time actually recorded. A clip that plays and then freezes was rebuilt over incomplete media data.
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 Canon MP4 recording card be recovered in this situation?+
The frames written before the power cut are usually on the card; what is missing is the closing step. An MP4 needs its moov section, written when recording stops, plus a committed directory entry. Without those the clip exists as data but not yet as a playable file. The result still depends on what remains readable on the source.
What should I avoid before scanning?+
Do not run a repair tool against the card or against your only copy, and do not let the camera attempt its own recovery routine first.
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 copy is good when it plays from the first second to the last, when picture and audio stay in sync right to the end, and when the duration is close to the time actually recorded.