DVD Demystified

DVD Overview
two common file systems on DVD; in fact, most discs contain both. Because
DVDs are simply storage media, other file systems such as Microsoft FAT,
NTFS, Macintosh HFS, UNIX, and so on can be used to write data files to
the disc. Compatibility problems generally occur only with these specialized
file systems, such as when a disc formatted with Windows FAT32 is placed
in the drive of a Mac.
Application Compatibility
Application compatibility is the most confusing area. It is not always clear
why a disc does not work in a specific player because it may not be obvious
which application formats the player supports. For example, a DVD-Video
player can read the data and UDF files on a DVD-Audio disc, but if it is not
built to read and process data from the DVD-Audio files in the AUDIO_TS
directory, it will not play the audio. Both the player and the disc say “DVD”
on them, but it may not be clear why they do not work together. The proliferation
of DVD Forum application formats such as DVD-VR and DVD-AR,
along with other custom formats for computers and game consoles, places a
burden on the consumer to understand which discs use which application
formats and which players can play them.
Implementation Compatibility
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Implementation compatibility has to do with flaws or omissions in players
(including computers and any other device that can play DVDs). Some players
are poorly designed, whereas others behave in unexpected ways with
unanticipated content. Each player implements the DVD specification in a
slightly different way, complicated by the fact that the specification is
ambiguous and confusing. The result is that discs may play differently or
not play at all in different players. Implementation errors also can occur on
the other side as well. That is, a bug might exist in the encoder or in the system
used to author the disc, or the person who authored the disc may have
done something that is not allowed by the DVD specification and thus does
not work on some or all players. Implementation problems are discussed in
more detail under “Playback Incompatibilities” in Chapter 7.