Given the source, the video is likely one of the following: A fan-made character edit or tribute.
This is a standard MPEG-4 file and should be playable in any modern media player like VLC Media Player or standard OS players. Recommendation
May refer to a video aspect ratio, a grid-style edit (4 by 8 layout), or a specific sequence number in an album. Unique Tag
Large social media dumps or archives often use these cryptic strings. The "4x8" and "3ng" are likely internal database markers or automated file-renaming tags used during a bulk download from the VK servers.
A recorded shared within a VK discussion thread. Technical Summary