: Use VLC Media Player . It is the most robust tool for opening .mp4 files that might have unique codecs or minor header corruption, which is common with dashcam footage.
: If the file was "lost" or deleted, it can often be recovered from the SD card using tools like PhotoRec or Recuva , as long as the card hasn't been overwritten by new footage. Common Contexts for This File Type RTS0929 2 mp4
: This is often the manufacturer's prefix. It is most commonly associated with R-Tech or Reolink security systems, or certain generic Chinese-manufactured dashcams and body cams. : Use VLC Media Player