Preserve the interrupted output
An interrupted recording can have a different structural outcome depending on how it was written. Keep the available bytes unchanged and preserve logs or recorder context where available. Do not repeatedly overwrite the only file with repair attempts.
FFmpeg's muxer documentation distinguishes ordinary and fragmented MP4 writing and describes different interruption-related characteristics. That does not guarantee recovery of any particular file. The first task is to identify the actual format and what data remains.
Record the last known complete source moment if the production has one. A file that opens is not necessarily complete, and a file that will not open may still warrant a specialist inspection of retained data.
Separate recovery from recreation
Inspect the tail with an appropriate documented workflow and save any candidate to a new path. Review the last usable picture and audio, including whether the final word or action is cut. Keep the recovered asset's duration and limitations explicit.
An imagined seminar recording may recover most of the presentation while lacking the closing questions. Label that as a partial recording. No container rewrite can promise to create footage that was never retained.
Retain both the original interrupted file and the processing record according to the project's needs. Confirm the derivative's beginning, seeking and required tracks as well as its ending. A successful recovery tool exit is only one structural observation, not complete editorial acceptance.
Questions answered
Does opening after a repair prove the recording is complete?
No. Review the intended endpoint and required content.
Can a remux recreate footage that was never written?
No. Recovery is limited by the data actually retained.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.