Difference Between VTS_01_0.VOB and VTS_01_1.VOB
In a standard DVD-Video structure, VTS_01_0.VOB and
VTS_01_1.VOB serve entirely different operational roles
despite sharing the same file extension and title set. While both are
MPEG-2 program stream containers, VTS_01_0.VOB contains the
interactive menu assets for the first video title set, whereas
VTS_01_1.VOB contains the first segment of the actual video
program (such as the main movie or an episode). Understanding the
difference between these two files requires examining how the DVD-Video
standard organizes navigation, user interaction, and media streams.
The Role of VTS_01_0.VOB: Title Set Menu
In DVD specifications, a VOB file with an index of 0
within a title set—such as VTS_01_0.VOB—is designated as
the Video Title Set Menu (VTSM_VOBS).
Its functional characteristics include:
- Interactive Navigation: This file houses the video backgrounds, audio loops, and subpicture streams that form the graphic interface of the menu (e.g., scene selection, audio setup, subtitle selection).
- Button Overlay Data: The subpicture streams inside this file contain highlight masks and color schemes used to indicate active, selected, or pressed buttons when navigated by a remote control.
- Standalone Execution: A DVD player only loads this file when directed to enter the menu domain for Title Set 01, either automatically on disc insertion or when the user presses the "Menu" button.
- File Size: Menus rarely exceed 1 GB, meaning a title set virtually never requires more than one menu VOB. If Title Set 01 has no dedicated menu, this file does not exist at all.
The Role of VTS_01_1.VOB: Title Program Stream
A VOB file with an index of 1 or higher—such as
VTS_01_1.VOB—belongs to the Video Title Set Title
(VTSTT_VOBS). This is the actual audiovisual content the user
watches.
Its functional characteristics include:
- Primary Content Storage: It contains the main video stream, multiple audio tracks (such as Dolby Digital, DTS, or director's commentaries), and standard subtitle overlays for the primary feature.
- Segmented Playback: Because the DVD standard relies
on the UDF 1.02 file system, individual files cannot exceed 1 GB
(1,048,576 KB). To accommodate full-length films, the main title is
split sequentially into consecutive chunks:
VTS_01_1.VOB,VTS_01_2.VOB,VTS_01_3.VOB, and so forth.VTS_01_1.VOBrepresents the beginning (the first 1 GB) of this playback sequence. - Continuous Streaming: The media in
VTS_01_1.VOBis designed for seamless, continuous playback, driven by cell and chapter pointers defined in the correspondingVTS_01_0.IFOfile.
Key Functional Differences
| Feature | VTS_01_0.VOB | VTS_01_1.VOB |
|---|---|---|
| Domain | Video Title Set Menu (VTSM) | Video Title Set Title (VTSTT) |
| Primary Purpose | Menu screens, audio loops, button graphics | Main feature/movie audiovisual stream |
| User Interaction | Waits for user input (navigation buttons) | Plays linearly through chapters/cells |
| Splitting Behavior | Solitary file; rarely approaches 1 GB | First file of a split sequence
(_1, _2, _3...) |
| Necessity | Optional (only present if the title set has a menu) | Mandatory (if Title Set 01 contains video content) |
In short, deleting or corrupting VTS_01_0.VOB breaks the
title set's menu navigation, while deleting or corrupting
VTS_01_1.VOB corrupts or removes the opening portion of the
actual video program.