Many digital video recorders (DVRs) and CCTV systems use "PM" (often short for "Picture" or "Post-Meridiem") followed by a sequence number. would typically be the 20th clip in a recorded sequence. 2. Project or Media Management
If you have the file and are unsure what is in it, you can safely inspect it using these methods: PM020.mp4
Based on standard naming patterns, this file likely falls into one of the following categories: 1. Security or Surveillance Footage Many digital video recorders (DVRs) and CCTV systems
: Right-click the file and select Properties > Details (Windows) or Get Info (macOS) to see the date it was created, which may provide a clue to its origin. PM020.mp4
: It likely uses the H.264 (AVC) or H.265 (HEVC) video codec.