PC hard-crashed during recording, how do I actually repair the file?

[Arkios]

I've already done the basic steps, recordered in MKV, searched around for a solution long enough for the file to now be more than 0KB...
but I simply can't find any guides for how to actually DO the recovery, only a shitton of posts that 100% end with "mp4 can't be repaired, you should switch".
Even Google only points me back to all the posts on this site, NONE of which mention how you could repair an MKV.

I would really appreciate some help.

Not sure which is the correct log file for this. The crash was around 1:00, so I'm attaching both the one from around the time I started OBS and the first one after the crash, since I don't know which one is relevant, or even helpful.
Although, the first one is not even half the size of the others, so it is probably that one ;~}

 

[FerretBomb]

An MKV should not need repair. On a crash, it simply truncates the recording, losing the last few seconds. It should open and play back normally up to that point. It can have some messed-up metadata, which shouldn't affect playback. If the file-size is showing as 0KB, you can copy/paste it into the same directory, and the copied file should have the correct file size data.

If the entire system crashed during recording, that could end up corrupting the NTFS file write process... that's journalled so it SHOULD self-recover, and repair with a scandisk at most. The one time I had that happen though, the entire disk was completely corrupted (apparently the journal index itself was taken out).

One option is to try using the 'remux recordings' option in OBS under the File menu, and see if it delivers a non-problematic MP4. If that fails, you can give MKVToolNix a try. I'll repair my own problematic recordings using Matroska's mkclean utility. There's also Meteorite.

Matroska Media Container Homepage

matroska.org

 

[Arkios]

As I said, I had already waited long enough for the file to no longer be 0KB, because I did research without any success.
I can open it in VLC, but the progress bar just has a yellow line bouncing towards the right and it doesn't play.

Scandisc said it found an error somewhere, but it didn't change anything for the file.
Remuxing fails, because "file may be incomplete", it also creates a 0KB file that I can't even find inside the folder, only in "recently used".
MKVToolNix tells me, that the file format is incompatible. Meteorite does absolutely nothing (but also doesn't really do anything with working files, just creates a tiny file with the same name in it, that doesn't do anything).
I have no idea how I would go about using mkclean, so that might work... if I knew how.

 

[dcmouser]

Separate report on system crash, a 3 hr recording is left as a 0byte unrecoverable file that scandisk says no errors found.
This is a pretty scary situation where a very long recording would be completely lost on a computer crash.
If there's any way to avoid this it would be very welcome.

(windows 10 ntfs)

CORRECTION:
Windows 10 tool to check disk reported no errors. Running chkdsk /f did seem to restore the 0byte file to its full size (10gb), with nothing lost. That's a big win! Good work OBS team and MKV.

 

[MiratopiaTech]

Separate report on system crash, a 3 hr recording is left as a 0byte unrecoverable file that scandisk says no errors found.
This is a pretty scary situation where a very long recording would be completely lost on a computer crash.
If there's any way to avoid this it would be very welcome.

(windows 10 ntfs)

CORRECTION:
Windows 10 tool to check disk reported no errors. Running chkdsk /f did seem to restore the 0byte file to its full size (10gb), with nothing lost. That's a big win! Good work OBS team and MKV.

Thanks! Your "CORRECTION" helped me recover my MKV file, which was showing 0 bytes at first when my computer froze after an hour of recording. CHKDSK /F fixed the file for me! Not sure why but this problem seems quite rare for others as your message is the only source of help out of a handful of sites/pages I've found, but this problem's happened to me before.