_m_smp4 -

: Files starting with an underscore or period are often treated as hidden or system-specific files. If you found this in a system folder, it is likely a pointer or index file for a video gallery. How to handle this file:

: Use a tool like MediaInfo or VLC Media Player to "Open" the file; these can often read the internal header to tell you the true codec, even if the file extension is non-standard. _m_smp4

: If you believe it is a video, try copying the file and changing the extension strictly to .mp4 . : Files starting with an underscore or period