: This usually stands for " Sub-stream " or " Sub-file ." In surveillance, a "Sub-stream" is a lower-resolution version of a video (e.g., VGA or 720p ) used for remote viewing or mobile playback to save bandwidth, while the "Main-stream" records in Full HD or 4K .
: If it is from a security system (like Hikvision, Dahua, or Lorex), you may need their specific "Player" utility available on the manufacturer's support page. 38495-60 601531470826_Sub_f_1532160055.mp4
: The VLC official site offers a player that can handle almost any codec. : This usually stands for " Sub-stream " or " Sub-file
: The most common video container format , typically using the H.264 codec to balance quality and storage. How to View This Content 38495-60 601531470826_Sub_f_1532160055.mp4