Vdx_10_ev.mp4 -

If this file appeared on your device unexpectedly, it may have been saved through a management app like the VDX Video Downloader.

The filename appears to be a specific video file, possibly a demo or "evaluation" clip (denoted by "ev") used for technical testing. While "deep piece" is not a standard industry term, it likely refers to one of two things in this context:

Knowing if it was in a professional video editor or a personal download folder could help pin down its exact purpose.