DVD-Video File Structure
DVD-Video combines VOB media files with IFO navigation information and backup files inside a VIDEO_TS directory.
Open a VIDEO_TS folder and its files describe a DVD presentation at several levels. The filesystem locates files; DVD navigation selects a title and its sequence; the VOB media supplies encoded picture, sound, and subpictures.
| Example filename or type | Role |
|---|---|
| VIDEO_TS.IFO | Disc-level manager information, including title relationships |
| VTS_01_0.IFO | Information for title set 1 and its programmes/navigation |
| .BUP | Backup of corresponding IFO information |
| VTS_01_0.VOB, where present | Menu video objects for that title set |
| VTS_01_1.VOB and subsequent numbered parts | Title-set video objects containing media |
The filename sequence describes storage organization. It is not itself an instruction to play every VOB as an independent movie.
Choose a title and resolve its sequence
A DVD-aware reader obtains disc-level information and follows the selected title into its title set. Within that structure, programme chains (PGCs) describe an ordered route through programmes and cells of video objects. Cells identify playable ranges; navigation can select angles, branches, and the route to follow.
Think of a simple invented chain as ranges A, C, and E from the stored objects. The player follows those ranges in order even if range B is physically between A and C on the disc. A linear concatenation of all stored bytes would instead include B. Both readers might decode valid MPEG media while presenting different content.
A chapter, or part-of-title entry, identifies a navigation starting point within the title's structure. It is not necessarily a VOB filename boundary. A film can cross numbered VOB parts in the middle of a scene while its chapter begins elsewhere.
Decode the selected media
Within the chosen video objects, program-stream-based packaging supplies the timed encoded components. The reader needs the intended soundtrack and subpicture descriptions as well as the video. DVD navigation and timing connect those pieces into the selected presentation.
Menu execution is another part of the disc experience. A DVD player can follow navigation commands and maintained state, whereas a file converter often resolves one selected title into a conventional linear output. Those are different consumer jobs applied to the same disc.
Folder, image, or a selected movie
A complete copied folder retains the file relationships. An image additionally retains the volume/filesystem around them. A remuxed feature instead writes the chosen title's components and timeline into one movie container, usually without reproducing the disc's menu logic.
For an Emby collection, use the movie organization guidance and identify which of these source forms is present. A lone VOB may initialize normally while representing only part of the intended feature. Title selection and scene order need to be resolved before evaluating whether the encoded video was preserved.
The public references describe filesystem and reader behaviour; the licensed DVD-Video Book is the format's detailed specification. The distinction keeps a useful structural explanation separate from claims to have reproduced the complete navigation standard.