Video · exFAT camera card
H.264 MP4: recover after an interrupted recording
What can I do with H.264 clips in an MP4 container after a recording interruption?
Short answer
Often the video data is there but the MP4 will not play: after power loss the moov index is frequently missing, because many cameras write it last. Keep the original untouched and remove the card. Repair only a copy, ideally with an intact reference clip recorded at identical resolution and frame rate.
The situation
H.264 clips in an MP4 container is missing, too short or unreadable after power loss, a card error or an unsafe stop.
Power cut out mid-take, so the recorder never got to close the file. The H.264 frames it had already written are on the card; what is missing is the small index at the end that tells a player where each frame begins.
01 / Diagnose
Work out what actually disappeared
Most cameras stream the encoded picture into the mdat area first and write the moov box, with its sample offsets and duration, only when you press stop. An unsafe stop, a flat battery or a card error interrupts that final write. The payload survives, but without moov no player can map it back to a timeline.
The payload may have been written before duration fields, indexes, directory entries or closing structures were committed. For H.264 MP4, this matters because ISO-BMFF boxes and an H.264 stream must agree on offsets, timing and length
Check the last known path, trash and backups without writing to the original device.
02 / Protect the source
Preserve the best recovery chance
- 1
Switch the recorder off properly and take the card out; do not let it try to finalise or fix the interrupted take by itself.
- 2
Note the camera model, the codec setting, resolution and frame rate of the take, and find an intact clip recorded with exactly those settings.
- 3
Copy the card or the truncated MP4 somewhere safe, or image it, and treat that duplicate as the only thing a repair tool may touch.
- 4
Let the repair tool rebuild the index on the copy using the intact clip as reference, then export the result to a separate drive.
Do not run the camera's own repair function on the original card, and do not let editing software import and rewrite the damaged file in place. Both can turn a recoverable stream into a shorter, permanently mangled one. Keep the untouched original until a repaired copy actually plays.
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 a truncated MP4 is file repair, and that is outside what File Recovery Hero does: it reads exFAT, NTFS and FAT volumes and raw images read-only to bring lost files back, but it cannot restore frames the recorder never wrote.
04 / Verify
Check the recovered content, not just its name
A repaired take opens without warnings, shows a duration close to how long you were actually filming, and scrubs smoothly along its whole length. Sound should stay in step with the picture from beginning to end; drifting audio means the rebuilt index has the wrong timing.
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 exFAT camera card be recovered in this situation?+
Power cut out mid-take, so the recorder never got to close the file. The H.264 frames it had already written are on the card; what is missing is the small index at the end that tells a player where each frame begins. The result still depends on what remains readable on the source.
What should I avoid before scanning?+
Do not run the camera's own repair function on the original card, and do not let editing software import and rewrite the damaged file in place.
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?+
A repaired take opens without warnings, shows a duration close to how long you were actually filming, and scrubs smoothly along its whole length.