The DVD (Video) file structure
To manipulate DVDs discs effectively, you need to understand a little about the file structure. This file structure is the same for all commercial DVD movies or DVD Video discs of your own home movies. The main data files have a VOB extension, but there are various types of VOB files and other files as well.
Here’s a brief guide:
VIDEO_TS.IFO. The ‘Video [Title Set] Manager Information Set’ is a configuration file that defines the disc structure and also includes region coding information.
VIDEO_TS.VOB. The ‘Video [Title Set] Object file for VMG Menu’, this file works like a bookmark to tell the player that it is the start of the disc.
VIDEO_TS.BUP. Backup file of the’ Video Manager Information Set’ (VIDEO_TS.IF0).
VTS_01_0.IFO. The’ Video Title Set Information Configuration` file for the first lot of VOB files, it also tells the player how to proceed when using the on screen menu system (essentially the first entry point and works like a marker). IFO files contain the formatting information of the VOB files, which tells the DVD player exactly how the DVD should be played (eg. aspect ratio, subtitles, languages, menus …). If you rip the DVD without IFO files, then the VOB files may not play correctly, or may not even play at all. Similarly for conversion, IFO files are essential for video converters which support IFO parsing; you will need them if you want to encode videos, or fix multi-angle ripping problems.
VTS_01_0.VOB. ‘Video Object Set for Video Title Set Menu’, the first video and audio stream sequence to be played usually the on screen menu system. These files may contain several streams of audio/video “multiplexed” (MUX) together (eg. chapters/language selections).
VTS_01_0.BUP. Backup file of the’ Video Title Set Information’ file (VTS 01_1.IFO).
VTS_01_1.VOB. The first ‘Video Title Object Set’ file, the main file containing the picture and audio streams. It is usually split into three to four files, each with ascending filenames; for example[ul][li]VTS_01_1.VOBVTS_01_2.VOBVTS_01_3.V0B[/ul]and so on. No VOB file is to exceed 1GB in size, with a maximum total of five VOB files in sequence on a single layer disc (DVD 5) and no more than nine on a dual layer disc (DVD 9). VOB files have a naming standard: where VTS_xx_yy.VOB[ul]xx - Title numberyy - Section number [/ul]A DVD can also include additional Video Title Sets that include the IFO, VOB and BUP with ascending filenames such as VTS_02_1, VTS_03_1 and so on. These are usually the extra features that come with the title, such as documentaries and behind-the-scenes footage. They can also be copied individually to your hard drive.
Each title has at least 2 VOBs (one for the menu and one for the main feature) and exactly one ifo and bup file.
The VIDEO_TS.* files represent the first play item. This is an item being set during authoring and is the first thing being played when the disc is inserted in the player. Usually this is just a copyright notice, but it could also be a menu where to select the language of the menu, some trailers, etc. The VIDEO_TS.VOB contains the video and audio data, the VIDEO_TS.IFO the navigational data and VIDEO_TS.BUP is the backup for VIDEO_TS.IFO.