Method to recover video files not finalised at capture?

[Fillimilli]

ello, I have a few files (2 to 3 gigs each , 4k 30fps) taken by an app (mcpro24fps, android, mp4) that are unreadable (eg. By VLC and other players, and VLC can't repair them).

I assume that I didn't finalise the videos by pressing the record button to finish the videos (stupid mistakes).

Is there a way to make them readable? Perhaps software (I tried a few windows apps though none seemed robust) or by appending the end of working videos recorded by the same app (doubt that would work).

I asked the developer who said it's not possible.

Thanks

[LoRd_MuldeR]

The "problem" with the MP4/MOV file format is that all audio+video data is stored in a single huge/unbroken block, the mdat atom. Unlike, e.g. MPEG-TS format, there are no separate "packets" that start with individual headers (sync sequences) and thus could easily be recovered, even from an "incomplete" stream. Instead, the MP4 file should contain a moov atom somewhere. The moov atom contains information about the tracks in the file. And, for each track, it contains tables that tell you the offset (start position) and the length (in bytes) of each frame. Unfortunately, when a new MP4 file is "recorded", then the moov atom is usually written at the very end of the MP4 file, after all the audio and video data has been written out! So, if you have an incomplete MP4 file that was never properly "finalized" and therefore is missing the moov atom, then it could be very difficult (or even impossible) to recover... :o

This tool may give you some insight (use the "Analyze" tab to see what your file actually contains):
https://www.videohelp.com/software/MP4Muxer

[Fillimilli]

Thank you, will try it out!

[Brazil2]

Dumpster might also help:
https://forum.doom9.org/showthread.php?t=183849

[Fillimilli]

Dumpster might also help:
https://forum.doom9.org/showthread.php?t=183849

Thanks, though weirdly, when attempting to run it a big blue dialog box appears saying "this app can't run on your PC" (win 11 box)

[Frank62]

I didn't try myself, but:
https://github.com/anthwlock/untrunc
seems to repair the missing atoms, if you provide a similar working video.