DVD Demystified

Application Details: DVD-Video and DVD-Audio
■ A specific directory (VIDEO_TS or AUDIO_TS) must be present and
must contain a specific file (VIDEO_TS.IFO or AUDIO_TS.IFO).
These constraints apply only to the directory and files that the DVD
player needs to access. Other files and directories can exist on the disc that
are not intended for the DVD player and do not meet the preceding listed
constraints. Such directories and files must be physically located on the disc
following the audio zone and video zone and are ignored by DVD players
(unless the DVD player employs extensions to the DVD standard). This
allows many kinds of data and applications to coexist with DVD-Video,
DVD-Audio, or data.
The DVD-Video specification prescribes a directory and set of files within
the UDF file format. All files are stored in one directory (VIDEO_TS). DVD-
Audio information is stored in a homologous directory (AUDIO_TS). An
optional, root-level directory (JACKET_P) can contain identifying images
for the disc in three sizes, including thumbnails for graphic directories of
disc collections.
For a DVD-Video volume, the required VIDEO_TS.IFO file contains
the video manager title set (main menu) information (VMGI). Additional
.IFO files hold other title set information (VTSI), with backup copies in
.BUP files. For each video title set on the disc, there can be up to 10 .VOB
files that hold one chunk from video object set blocks. Likewise for DVD-
Audio volumes, the required AUDIO_TS.IFO file contains the audio manager
title set (main menu) information (AMGI). Each audio object set is
broken into .AOB files (see Figures 6.4 and 6.5, as well as “Physical Data
Structure,” later in this chapter).
DVD-Video
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DVD-Video provides one stream of MPEG-2 variable-bit-rate video with up
to 9 interleaved camera angles; up to 8 streams of Dolby Digital multichannel
audio, MPEG-2 multichannel audio, or linear PCM audio; and up
to 32 streams of full-screen graphic overlay subpictures supplemented with
navigation menus, still pictures, seamless branching, parental management,
and rudimentary interactivity. The DVD-Video format is designed for
playback on standard 525-line (NTSC) and 625-line (PAL) television displays
via analog video connections. It also can be played in standard resolution
in interlaced or progressive format on digital displays and
high-definition televisions via analog or digital connections.