Video · damaged MP4 video media
MP4 with audio but no picture: recover after an interrupted recording
What can I do with recovered MP4 files that play audio only after a recording interruption?
Short answer
Often the video index is the problem: after an interrupted recording, a repaired MP4 that plays only audio has its audio samples indexed but not its video frames. Keep the original untouched and retry the repair on a fresh copy, using a reference clip with identical codec, resolution and frame rate.
The situation
recovered MP4 files that play audio only is missing, too short or unreadable after power loss, a card error or an unsafe stop.
After an interrupted take the picture is usually still inside the file and the rebuilt index simply fails to describe it. Audio samples are small and regular, so a repair tool maps them easily, while video frames need correct offsets and sizes that a partial rebuild does not always produce.
01 / Diagnose
Work out what actually disappeared
The recording ended before the moov atom was written, so the repair had to derive the sample table from a reference clip. If that reference differs in codec, resolution or frame rate, the audio lines up while the video mapping misses the real frame boundaries. The picture data lies in the file, but nothing points at it correctly.
The payload may have been written before duration fields, indexes, directory entries or closing structures were committed. For MP4 with audio but no picture, this matters because an audio track can remain readable while the video track or its sample mapping is damaged
Check the last known path, trash and backups without writing to the original device.
02 / Protect the source
Preserve the best recovery chance
- 1
Set the original unfinished clip aside untouched and work only on fresh copies for each new repair attempt.
- 2
Record a reference clip with exactly the same camera, codec, resolution, frame rate and bitrate as the damaged take.
- 3
Run the repair again on a new copy with that reference, rather than repairing the earlier result a second time.
- 4
Check every attempt in a player that decodes the codec and keep the version showing the longest picture.
Do not chain repairs on top of each other: a second pass over an already rebuilt file starts from a wrong sample table and buries the original offsets. Do not delete the source clip or clear the card while any attempt still produces sound only.
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 card read-only and recovers files that are missing or deleted; it does not rebuild indexes or repair single damaged clips, so container work belongs to a dedicated tool. Without a matching reference clip from the same camera mode, no tool can map the frames reliably.
04 / Verify
Check the recovered content, not just its name
The rebuild is right when the picture appears from the first frame, stays in step with the audio and the duration matches the time the camera was actually rolling. A file that plays sound to the end but shows a frozen image or nothing still has a broken video sample table.
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 damaged MP4 video media be recovered in this situation?+
After an interrupted take the picture is usually still inside the file and the rebuilt index simply fails to describe it. Audio samples are small and regular, so a repair tool maps them easily, while video frames need correct offsets and sizes that a partial rebuild does not always produce. The result still depends on what remains readable on the source.
What should I avoid before scanning?+
Do not chain repairs on top of each other: a second pass over an already rebuilt file starts from a wrong sample table and buries the original offsets.
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 rebuild is right when the picture appears from the first frame, stays in step with the audio and the duration matches the time the camera was actually rolling.