[witanime.com] Smnb Ep 12 - End Bd-hd.mp4

Artifacting, dropped frames, or encoding errors.

Likely an abbreviation for the anime title (e.g., Shinmai Maou no Testament or similar, depending on their naming convention). EP 12 END: The final episode of the season/series. [Witanime.com] SMNB EP 12 END BD-HD.mp4

If you see in a file name, it is almost always the best version to download , as it solves a known problem found in the "Internal" or original release. Artifacting, dropped frames, or encoding errors

The site or group that encoded/uploaded the file. Shinmai Maou no Testament or similar