The MP4/MOV video files have the time codes embedded in the files, such time codes are stored in the video files when they are recorded. But the time codes are not visible when you view the MP4/MOV files. When you use video edit tools to convert the MP4/MOV files to other format files, the time codes get lost. By using vMTS the time codes are extracted from the MP4/MOV files and superimposed onto the videos. This way the date/time will be visible when you view the stamped file, consequently other format files made out of the stamped files will have date/time displayed.