: The VLC official site offers a player that can handle almost any codec.
: 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 . 38495-60 601531470826_Sub_f_1532160055.mp4
: If this was found in a cloud backup (like Google Photos or iCloud), the "Sub" prefix might indicate it is a low-quality preview generated by the service while the full file is processing. : If this was found in a cloud
If you have this file and cannot open it, it may be due to a proprietary codec used by a security system. To view it, try:
: 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.