Use a tool like MediaInfo to see the technical metadata (resolution, frame rate, and what software encoded it).
If you found this file on your computer or a shared drive, it is most likely: 2021-08-07 03-37-54.mkv
The filename appears to be a default timestamp-based name typically generated by recording software like OBS Studio , ShadowPlay , or security camera systems . Use a tool like MediaInfo to see the