How to fix unprocessed file which was interrupted?

- [x ] I have read the [FAQ](https://github.com/Genymobile/scrcpy/blob/master/FAQ.md).
- [x ] I have searched in existing [issues](https://github.com/Genymobile/scrcpy/issues).

**Environment**
- OS: [e.g. Debian, Windows, macOS...] Arch Linux
- scrcpy version: [e.g. 1.12.1] version 2.1
- installation method: [e.g. manual build, apt, snap, brew, Windows release...] pacman
- device model: OnePlus Nord 2 5G
- Android version: [e.g. 10] Android 11

I started recording over wifi but I forgot to connect my laptop to power so it eventually ran out of battery and now I have an incomplete unprocessed file. How do I fix this? I tried `Avidemux`; it said file not found even though I have the file. I used `ffmpeg` and it gave this error:
```
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x55fbf7cbe340] moov atom not found
noelli08072.mp4: Invalid data found when processing input
```

Start with FAQ.md and the reported ffmpeg error, focusing on the interrupted recording and the missing moov atom. Compare the behavior with the Avidemux and ffmpeg attempts; done means determining whether the incomplete file can be recovered or clearly documenting that it cannot.

Written by the indexing model from the issue text.