Audio · exFAT field recorder card
Broadcast Wave/BWF: recover after an interrupted recording
What can I do with BWF recordings with production metadata after a recording interruption?
Short answer
Often the take is salvageable: an interrupted BWF typically holds its bext metadata before the audio, but the chunk sizes were never finalized. Copy the file, correct the RIFF and data sizes on the copy, and check whether an iXML chunk the recorder writes at the end is missing, then restore scene data from your report.
The situation
BWF recordings with production metadata is missing, too short or unreadable after power loss, a card error or an unsafe stop.
An interrupted take keeps the metadata written at the start and loses the bookkeeping that belongs at the end. The bext chunk usually survives, while the RIFF and data sizes were never finalised, and an iXML chunk that your recorder appends last may be missing altogether.
01 / Diagnose
Work out what actually disappeared
Recorders write the header, then the audio, then close the file by correcting the chunk sizes and, on many models, appending iXML. Power loss between those stages leaves a file whose samples are present but whose length fields still hold placeholders, so a player reports nothing at all or a fraction of the real take.
The payload may have been written before duration fields, indexes, directory entries or closing structures were committed. For Broadcast Wave/BWF, this matters because bext, iXML and timecode metadata may matter alongside the PCM payload
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 recorder down, remove the card and copy the affected take before any tool opens its header.
- 2
Correct the RIFF and data chunk sizes on the copy to the real file length, leaving the original as it is.
- 3
Check whether an iXML chunk is missing at the end and note which fields it would have carried.
- 4
Restore scene, take and roll from the sound report into the copy once the audio plays completely.
Do not let the recorder finalise the take on the card, and do not correct the header of your only file. A wrong size value makes the take unreadable, and adding metadata before the sizes are right can push the chunk boundaries further out of line.
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 recorder card read-only and recovers takes that vanished from the directory; it does not correct chunk sizes, rebuild iXML or repair damaged individual files. That part belongs to an audio tool working on a copy, with your sound report as the reference.
04 / Verify
Check the recovered content, not just its name
The take is usable when its duration matches the report, the audio runs to the moment the power failed and the bext timecode still starts where it should. Playback at the wrong speed or with added hiss means the format fields were damaged too and must be set from the recorder settings.
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 field recorder card be recovered in this situation?+
An interrupted take keeps the metadata written at the start and loses the bookkeeping that belongs at the end. The bext chunk usually survives, while the RIFF and data sizes were never finalised, and an iXML chunk that your recorder appends last may be missing altogether. The result still depends on what remains readable on the source.
What should I avoid before scanning?+
Do not let the recorder finalise the take on the card, and do not correct the header of your only file.
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 take is usable when its duration matches the report, the audio runs to the moment the power failed and the bext timecode still starts where it should.