640_147.mp4 -

If the video won't play, use a tool like MediaInfo to check if it requires a specific proprietary codec used by a learning management system. If you'd like more specific help, could you tell me :

If you downloaded this from a platform like Nowcoder or Bilibili, look for a corresponding "Problem ID" or "Lesson Title" on that site to find the written context.

What is the of the video (e.g., a whiteboard, a code editor, a nature scene)? 640_147.mp4

Often used to group programming challenges for specific Chinese tech firms (e.g., Kuaishou, Tencent, or Sangfor).

If you have a file named 640_147.mp4 , it is most likely a , a lecture, or a video tutorial explaining the problem sets associated with that specific tag. 💡 Common Uses for "640_147" If the video won't play, use a tool

Where did you (e.g., a specific website or course)?

Standard players like VLC Media Player can open almost any .mp4 file, regardless of the cryptic filename. Often used to group programming challenges for specific

The identifier appears to be a internal tag used by the technical recruiting platform Nowcoder (牛客网) to categorize specific coding problems or company-specific recruitment content. In this context, it likely refers to a practice test or interview preparation module for a tech company like Kuaishou (快手).