HD DVD Structure

This section provides technical reference material for all users. A more informal treament can be found in the Getting Started section.

An HD DVD contains two types of contents: one is Standard Content and the other is Advanced Content. Standard Content is a pure extension of SD, as described in DVD-Video specification Version 1.1.

Advanced Content consists of Advanced Navigation such as Playlist, Manifest, Markup and Script files, and Advanced Data such as Primary/Secondary Video Set and Advanced Element (image, audio, text, etc.). At least one Playlist file and Primary Video Set must be on a disc which has Advanced Content, and other data can be on a disc and also be delivered from a server.

The specification allows two Categories of discs, Standard Content and Advanced Content.

Advanced Data and Standard Content both contain EVOBs, which consist of video, audio, subpicture, and other data multiplexed together. Standard Content EVOBs contain button highlight and other information that is not used in Advanced Content. Advanced Content EVOBs may contain copies of some Advanced Content files, multiplexed in with the video, audio and subpicture data as Archiving data.

An HD DVD has a Volume and File Structure and a set of Directory and File Rules. Volume space is divided into zones for HD DVD-Video and DVD others (commonly referred to as ROM data).

The top level of the DVD must always contain a folder with the name HVDVD_TS. If the DVD contains Advanced Content, it must also have a folder with the name ADV_OBJ at the top level.


Advanced Content

Advanced Content consists of the following:

A Playlist chooses the sequence of presentation objects to be played. For example, to play back the Primary Video Set, the player player might start by reading a TMAP file by using the URI described in the Playlist, then interpret an EVOBI referred to by the TMAP, and access the appropriate P-EVOB defined in the EVOBI.

In this case the TMAP is a file with extension .MAP, the EVOBI exists within the one and only Advanced Video Title Set file (extension .VTI), and the P-EVOB exists with the EVOB file with same name as the TMAP file, with extension .EVO. All of these files are found in the HVDVD_TS folder.

To present Advanced Application, which means construct video rather than playing it directly, a player reads a Manifest file by using the URI described in the Playlist, and starts to present an initial Markup file described in the Manifest file after storing resource elements (including the initial file).

In this case the Manifest and other Advanced Application files are found in the ADV_OBJ folder.

Here is a table that shows the Relation among Presentation Objects in Advanced Content.


Playlist

A Playlist file is described by XML and one or more Playlist files are located on a disc. The Playlist file is what starts the playback of Advanced Content.

A Playlist file consists of the following information:

Object Mapping Information

Object Mapping Information gives playback information among presentation objects such as Primary Vide Set (Primary Audio Video), Secondary Video Set (Substitute Audio Video/Substitute Audio/Secondary Audio Video), Advanced Application and Advanced Subtitle, by mapping these presentation objects on the Title Timeline. In Object Mapping Information, Primary Video Set or Secondary Video Set is referred to via the URI of its Time Map file, and Advanced Application or Advanced Subtitle is referred to via the URI of its Manifest file.

Track Number Assignment Information

In this information, streams and applications in each presentation object such as Main Video stream, Main Audio stream, Sub Video stream, Sub Audio stream, Sub-picture stream and Advanced Application are assigned to Tracks such as Video Track, Sub Video Track, Audio Track, Subtitle Track, and Application Track.

Track Navigation Information

This information gives a list of user selectable Tracks, which is defined in the Track Number Assignment Information and attribute information such as language code for each Track.

Resource Information

This information gives the timing when resource files (i.e. Advanced Elements) need to be loaded in the File Cache and the timing when the resource files are referred to in Advanced Applications(s).

Playback Sequence Information

Playback Sequence Information gives chapter information in a Title, by indicating time points in the Title Timeline.

System Configuration Information

System Sequence Information gives information for system configuration such as Streaming Buffer Size.

Scheduled Control Information

Scheduled Control Information gives information for Scheduled Pause and Event Firing of Title Timeline at the specified time.


Primary Video Set

Primary Video Set in Advanced Content consists of Advanced VTS space, Standard VTS space, and VMG. Basically Advanced VTS is used only in Advanced Content, and Standard VTS may be used in Advanced Content even though this VTS is mainly used for Standard Content. In Advanced Content, VMG may exist in the Primary Video Set, however the transition to VMGM_DOM or FP_DOM is not allowed.

Advanced VTS

Advanced VTS is used for the Video Title Set for Advanced Content. Compared to Standard VTS, it supplies the following enhancements.

1) More enhancements for an EVOB

  • 1 Main Video stream
  • 8 Main Audio streams (max)
  • 1 Sub Video stream
  • 8 Sub Audio streams (max)
  • 32 Sub-picture streams (max)
  • 1 Advanced stream

2) Integration of the Enhanced VOB Set (EVOBS)

  • Integration of both Menu EVOBS and Title EVOBS

3) Elimination of a layered structure

  • No Title, no PGC, no PTT and no Cell
  • No support for Navigation Commands and UOP control

4) Introduction of new Time Map Information (TMAPI)

  • For a Contiguous Block, one TMAPI corresponds to one EVOB and it shall be stored as a file with the same base name as the EVOB.
  • For an Interleaved Block, the TMAPIs which correspond to EVOBs in the Block shall be stored as a file.
  • Some information in a NV_PCK is simplified.


Standard VTS

Standard VTS is normally used in Standard Content, however it may be used in Advanced Content via the TMAP structure. The EVOB information for Standard Content, such as HLI and PCI (button highlights, etc.) is ignored if the Standard VTS is used in Advanced Content.


Secondary Video Set

The Secondary Video Set is used for substitution of the Main Video/Main Audio streams to the corresponding streams in the Primary Video Set (Substitute Audio Video), substitution of the Main Audio stream to the corresponding sream in the Primary Video Set (Substitute Audio), or used for addition to/substitution of the Primary Video Set (Secondary Audio Video).

The Secondary Video Set may be recorded on a disc, recorded in Persisent Storage or delivered from a server. The file for the Secondary Video Set is once stored in the File Cache or Persistent Storage before playback, if the data is recorded on a disc, and it is possible to be played with the Primary Video Set simultaneously. The Secondary Video Set on a disc may be directly accessed in case that the Primary Video Set is not played back (i.e. it is not supplied from a disc). On the other hand, if the Secondary Video Set is located on a server, all of this data should be stored once in the File Cache or Persistent Storage and played back ("Complete downloading"), or a part of this data should be stored in the Streaming Buffer sequentially and played back from the buffer while downloading, without the buffer overflowing.


Secondary Audio Video

Secondary Audio Video contains zero or one Sub Video stream and zero to eight Sub Audio streams. This is used to add to the Primary Video Set or to substitute the Sub Video stream and a Sub Audio stream in the Primary Video Set.


Substitute Audio Video

Substitute Audio Video contains one Main Video stream and zero to eight Main Audio streams. This is used to substitute for the Main Video stream and Main Audio stream in the Primary Video Set.


Substitute Audio

Substitute Audio contains one to eight Main Audio streams. This is used to substitute for the Main Audio stream in the Primary Video Set.


Advanced Application

An Advanced Application consists of one Manifest file, Markup file(s) (including content/style/timing/layout information), Script file(s), Image file(s) (JPEG/PNG/MNG/Capture Image Format), Effect Audio file(s) (LPCM wrapped by WAV), Font file(s) (OpenType) and others.

A Manifest file gives informatin for display layout, an initial Markup file to be executed, Script file(s) and resources in the Advanced Application.


Advanced Subtitle

Advanced Subtitle is used for subtitle synchronized with video, which may be for substitution of the Sub-picture data. It consists of one Manifest file for Advanced Subtitle, Markup file(s) for Advanced Subtitle (including content/style/timing/layout information), Font file(s), and Image file(s). The Markup file for Advanced Subtitle is a subset of Markup for Advanced Application.


Presentation Objects

Presentation Object Data Source Data Class Data Type Player Decoder
Primary Video Set Disc Primary A/V Main Video Primary Video Player Main Video Decoder
      Main Audio   Main Audio Decoder
      Sub Video   Sub Video Decoder
      Sub Audio   Sub Audio Decoder
      Sub-picture   Sub-picture Decoder
Secondary Video Set Any(1) Substitute A/V Main Video Secondary Video Player Main Video Decoder
    Substitute Audio Main Audio   Main Audio Decoder
    Secondary A/V Sub Video   Sub Video Decoder
      Sub Audio   Sub Audio Decoder
Advanced Application File Cache(2) Markup/Script/Image/Effect Audio/Font Advanced Application Presentation Engine
Advanced Subtitle File Cache(2) Markup for Advanced Subtitle/Font/Image Advanced Subtitle Player

(1) Disc, Persistent Storage, Network or File Cache

(2) Resource files in a disc, in Persistent Storage, or in a network must be stored once in File Cache before they can be accessed.


Directory Rules

All HD DVD-Video discs must contain an HVDVD_TS directory at the top level. All files related with the Primary Video Set shall reside under this directory.

All discs containing Advanced Content must contain an ADV_OBJ directory at the top level. All Playlist files shall reside directly under this directory. Any files of Advanced Navigation, Advanced Element, and Secondary Video Set can reside directly under this directory.


HD DVD Categories

There are two HD DVD Disc Categories:

  • Category 1
    • This disc contains only Standard Content which consists of one VMG and one or more Standard VTSs.
  • Category 2
    • This disc contains only Advanced Content which consists of a Playlist, a Primary Video Set, Secondary Video Set, and an Advanced Subtitle.


Standard Content

Standard Content is just an extension of content defined DVD-Video Version 1.1 especially for high-resolution video, high-quality audio, and some new functions. Standard Content consists of one VMG space and one or more VTS spaces, which are called "Standard VTS" or just "VTS".

Some highlights of these extensions are:

  • Video stream extensions, more codecs and higher resolution
  • Audio stream extensions
  • Sub-picture stream extensions
  • Navigation Command extensions, including Resume commands
  • Elimination of some restrictions within domains
  • Elimination of some restrictions from transition among domains
  • Increase in number of GPRMs, Titles, and Chapters

Standard Content contains EVOBs, which consist of video, audio, subpicture, and other data multiplexed together. Standard Content EVOBs contain button highlight and other information that is not used in Advanced Content.

The ADV_OBJ folder

The ADV_OBJ directory must be present at the top level of all HD DVD discs containing Advanced Content. All Playlist files shall reside directly under this directory. Any files of Advanced Navigation, Advanced Element, and Secondary Video Set can reside directly under this directory.

Playlist

Playlist files have an extension of "XPL" (or "xpl").

A Playlist file may be necessary to be read from a disc as described in Startup Sequence of Advanced Content. In this case the file may be of two types, those with filenames "VPLSTxxx.XPL" for a player which connects with a dsiplay device, or the filenames "APLSTxxx.XPL" for a player which does not connect with a display device. xxx is a number between "000" and "999".

In this case, the Playlist file which has the maximum number shall be read initially in the startup sequence. The file must be found directly under the ADV_OBJ directory, not within its sub-directories.

Otherwise a playlist file may be found in sub-directories under the ADV_OBJ directory, and the file name rules are relaxed.

Configuration File

This file shall reside directly under the ADV_OBJ directory, and must have the filename "DISCID.DAT", even if functions for a network connection or Persistent Storage are not required in a disc.

Certificate

This file may reside directly under the ADV_OBJ directory, and has an extension of "CER" or "cer".

Directories for Advanced Content

Directories for Advanced Content may exist only under the ADV_OBJ directory. Any files of Advanced Navigation, Advanced Element and Secondary Video Set can reside in this directory. The number of sub-directories shall be less than 512, and directory depth shall be less than or equal to 8. (Excluding the ADV_OBJ directory itself). Directory names must conform to the character set described for files, below.

Files for Advanced Content

The total number of files under the ADV_OBJ directory shall be limited to 512 x 2047, and the total number of files in each directory shall be less than 2048. The character code set is limited to a subset of ISO 8859-1, that is: "A to Z a to z 0 to 9 space !$%&'(),-.;=@_" (20h, 21h, 24h to 29h, 2Bh to 2Eh, 30h to 39h, 3Bh, 3Dh, 40h to 5Ah, 5Fh, 61h to 7Ah). The length of the filename must not exceed 255 characters.

File names must be chosen so that they are unique in both case-sensitive and case-insensitive systems. All instances of the same name shall be recorded as if in a case-sensitive system, and the player shall preserve the upper and lower case of filenames.

It is acceptable for an HD DVD-Video disc to contain one or more zero byte files.

See File Extension and MIME Type for a list of the supported file types.




File Extension and MIME Type

Extension Content MIME Type
XPL Playlist text/hddvdpl+xml
XMF Manifest text/hddvdmf+xml
XMU Markup/Content text/hddvdmu+xml
XTS Timing Sheet text/hddvdts+xml
XAS Markup/Content for Advanced Subtitle text/hddvdas+xml
XSS Style Sheet text/hddvdss+xml
JS ECMAScript application/ecmascript
EVO Secondary Video Set EVOB video/evob
MAP Time Map application/tmap
BUP backup for Time Map application/tmap
JPG JPEG image image/jpeg
PNG PNG Image image/png
MNG MNG animation image/mng
CVI Capture Video Format image/cvi
CDW Capture Drawing Format image/cdw
WAV WAV audio audio/x-wav
OTF, TTF, TTC OpenType font application/font
ACA Archiving format application/archiving
CER Certificate application/x-x509-ca-cert
Others Others application/x-data


The HVDVD_TS Folder

This directory must exist at the top level of the HD DVD. All files related with the Primary Video Set must reside within this directory. For Standard Content these are the VMG and and Standard Video Set(s) . For Advanced Content, these are the files for Advanced VTS.

Video Manager (VMG)

  • The fixed filename for Video Manager Information shall be "HV000I01.IFO".
  • The fixed filename for the First Play Menu EVOB, if any, shall be "HV000M01.EVO".
  • The filenames for the VMG Menu EVOBs shall be "HV000Mxx.EVO".
  • The fixed filename for the Video Manager Information backup shall be "HV000I01.BUP".
  • xx shall be assigned consecutively from "02" to "99" for each EVOB, to keep files at 1 GB.

Standard Video Title Set (Standard VTS)

  • The filename for Video Title Set Information shall be "HVxxxI01.IFO".
  • The filenames for VTS Menu EVOBs shall be "HVxxxMyy.EVO".
  • The filenames for VTS Title EVOBs shall be "HVxxxTyy.EVO".
  • The filename for Video Title Set Information backup shall be "HVxxxI01.BUP".
  • xxx shall be assigned consecutively from "001" to "511" for the files of the Video Title Set number.
  • yy shall be assigned consecutively from "01" to "99" for each EVOB, to keep files at 1 GB.

Advanced Video Title Set (Advanced VTS)

  • The filename for Video Title Set Information shall be "HVA00001.VTI".
  • The filenames for VTS EVOBs shall have an extension of "EVO".
  • The filenames for Time Map Information for Contiguous Block shall have the same body in the filename as that of the corresponding EVOB, with an extension of "MAP".
  • The filenames for Time Map Information for Interleaved Blocks shall have the same body in the filename as that of corresponding EVOBs, with an extension of "MAP".
  • The filenames of Time Map Information for Standard VTS referred to from Advanced Content shall be "HVS0xxxx.MAP".
  • xxxx shall be four characters of "0001" to "1998" which is the same number as the EVOB index number assigned to each EVOBI and TMAP in the Video Title Set Information.
  • The filename for Video Title Set Information backup shall be "HVA00001.BUP".
  • The filename for Time Map Information backup shall have the same body in the filename as the corresponding Time Map Information, with an extension of "BUP".


Backup files are optional in Advanced VTS.


Volume Structure

Volume space is defined by a UDF Volume and File structure.

Volume space is divided into zones for HD DVD-Video and DVD others (commonly referred to as ROM data). THe HD DVD-Video zone is further divided into the Standard Content zone and the Advanced Content zone. The zones may be placed on the disc in any desired order.

Within the Standard Content zone, the Video Manager (VMG) is followed by one or more Standard Video Title Sets (VTS). Within these, the files must be named and written in a pre-defined order. (See Directory and File Rules).

The Advanced Content zone must contain an Advanced VTS title file, which must be named "HVA00001.VTI", and other Advanced Content files, whose file names are described in the title file.