What is the File Extension VOB?by Alan Donahue
DVD files are made specifically to play in DVD drives, and the only way to do this is by having properly rendered movie files. The VOB file is the proper DVD file, and the VOB extension is the only extension used to store video, special features, and menu data within a DVD. This file can be used in multiple ways, but many of them have to do with the DVD process.
VOB serves as the main file resource for burned DVD video files. DVD data files, music files, and game files usually do not contain VOB files---only DVD movies and television shows do. Along with the video and audio, VOB data files can store subtitles to multiple languages. The files contain triggers that DVD users can select in order to process the data within the VOB files.
VOB files cannot be directly seen on a DVD menu. The menu features shortcuts to the VOB files, all presented in a nice package. IFO files are also on the DVD. The IFO files help the DVD decipher where to start and stop certain sections of the DVD and also signify chapter marks.
VOB files on their own cannot be played on a computer unless a specific program is used. Video LAN, also known as the VLC, is a multiformat player that can handle and play VOB files. All players can play the files, but errors or distortion may occur. These programs include Windows Media Player Classic and the ALLplayer.
VOB actually stands for "video object." The basis of the video files is based on an MPEG-2 video-file system. This makes it a lot easier to burn MPEG-2 files to DVD, while AVI, WMV, and other video formats must be converted before they are burned to a DVD or they will not play properly in a DVD player.
The use of VOB files instead of regular video files enables DVDs to feature more encryption from pirating. There are plenty of programs used now to copy DVD files, but users cannot do much with the data that they directly copy from a drive to their computer. Improvements on the VOB file system will only make DVDs better and harder to copy in the future.
- link DVD Structure & VOB