Is it possible to capture video output

[trapexit]

Not sure if this is the right forum section but:

I've got a large number of mpeg files which have mostly minor but sometimes significant corruption. I've found that most of them will play to a reasonable degree with vlc and keep audio/video sync despite said corruption but when I use vlc or ffmpeg to transcode or remux things don't turn out nearly as good.

I've tried nearly every permutation of suggestion I can find online wrt "repairing" files using both apps. I've tried

vlc -I dummy input.mpeg --sout=file/ts:output.ts vlc://quit

ffmpeg -fflags +genpts -i input.mpeg -c copy -map 0 output.mpeg

and similar. And while sometimes it fixes timestamp issues but regularly results in av sync problems. Sometimes if I instead of "fixing" the file I just transcode it it might keep sync. Sometimes though the files are so bad off that the encoder gets screwed up and generates shortened files or confuses the encoder and gets stuck.

If I output raw data from ffmpeg, mplayer, or vlc I almost always get av sync problems. The thing that I've found to be most likely to "work" is just playing the file. Clearly the player behaves differently from the other code paths. That said I can't find an obvious way to take the literal av output and remuxing it into something that I could later encode. I've had to resort to using vlc to play videos and obs to record the output but... is there any way to do what I'm trying to do?

I have so many videos to process it would be great if I could automate processing these corrupted files and I'm hoping I'm just missing something in vlc's ability to process/output files. Any help here would be appreciated. I could likely throw together some automation to launch vlc and screen record it but I would really rather not.

A particularly badly corrupted file is: https://archive.org/download/Computer_C ... 88%29.mpeg