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					                       THE LAYMAN’S GUIDE TO
                       WAEA SPECIFICATION 0598
                                            Or
                                 Cliff’s Notes on 0598



General

DVD specification 0598 was written by representatives from laboratories, equipment
manufacturers, studios and airlines and is a highly technical document. This summary
of the key elements is intended to provide an interpretation of 0598 for users in non-
technical fields. It is not an official WAEA specification and, in any questions of
conflict, the true Specification 0598 will prevail.


DVD Applications (Ref: 0598 paragraph 1.3)

DVDs may be used in a variety of applications. These may be at the seat or incorporated
into a head end distribution system.

At-the-seat systems include:

   Installed player that resides in the armrest or other storage area, which the passenger
    or attendant can retrieve when desired.
   Hand-held personal portable DVD player that may be supplied by the airline, or an
    airline-supplied laptop computer with a DVD drive for playback. (Because of the
    region 8 encoding [which is covered later], a passenger’s personal laptop or
    portable DVD player will not play airline encoded DVDs.)

Head-end applications vary:

   Direct Play
    a) Overhead (Bulkhead) Displays: DVDs can be used as a source of content in the
       same way that videotape systems operate, using a DVD player in place of a VCR.
       The quality will not degrade and in fact will offer the same quality from first
       showing to last.
    b) Multi-Channel Distributed (PTV) Systems: Here again DVDs can be a source of
       video content to feed a multi-channel (PTV) system. With a multi-channel
       system, each DVD can be utilized as a channel of programming, which the
       passenger can select in the same way that video PTV systems are currently used.

   Transfer of movie files to head-end system: DVD, in the proper configuration as a
    data storage medium, can be used to transfer movie files to a head-end file server
    system rather than loading movies from tape. The DVD is easier to transport and the
    picture quality is as good as the master, so there’s no degradation, no mechanical or
    analog interfaces, and the signal is pure and the loading is quick. DVD also makes it
    easy to exchange individual movies from the play-list.
   Note: DVDs are encrypted with a security system called CSS, which we’ll discuss
    later, that prevents the copying of data from a DVD disc. Any head-end application
    for transferring data from a DVD will require a DVD specially authored for this
    application.

Many of these applications carry the capability of multiple languages and subtitles. A
DVD can be configured for up to 8 (eight) languages and up to 32 subtitles (turned on or
off). The airline makes the decision as to what languages and subtitles are used.

Definitions (Ref: 0598 paragraph 5)

These definitions are not in alphabetical order because they make more sense in the order
they are usually encountered.

DVD: DVD means Digital Video Disc. It is also called Digital Versatile Disc because of
its interactive capabilities. The DVD is a storage medium for high quality MPEG 2
compressed files. It offers extensive versatility, such as being able to handle up to 8
languages and 32 subtitles, wide-screen, surround-sound and interactive menus all on one
disc the size of a CD. But, there are limitations. A disc will hold only 4.7Gigabytes or a
little over two hours of good video and sound. This size DVD is called a DVD5. Start
adding several languages and features such as fancy menus (see Note About Menus
below) and the amount of space available for the movie decreases. That’s when you have
to start “bit budgeting,” the process of planning what you really want on the disc versus
how much space you have available. One solution for long movies with a lot of stuff
(assets) is….

Dual Layer (DVD9): DVDs have a unique ability to be able to be manufactured with
two layers. The player will read the first layer, then go back and read the layer underneath
the first. Now you can get that long movie and all those languages on one disc. The
drawback is that the DVD9s cost a bit more, are more sensitive to movement and they’ve
got to be perfect to work. The good news is that more and more players and
manufacturers are increasing the reliability of dual-layer discs.

Two-Sided (DVD10). The two-sided disc has a DVD5 on each side and is called a
DVD10 (two times five). The benefit is that it’s easier to manufacture than a DVD9 and
more reliable. You might have one set of languages and subtitles on one side and more on
the other or a different screen aspect ratio such as 16 X 9 or wide screen versus normal
TV aspect ratio. The drawback is you’ll have to remove the disc from the player and flip
it over to play the other side. With both sides having DVD data you won’t be able to print
anything on the disc.

DVD: Note About Menus: currently, menus for all airline DVDs are simple in nature
and use a generic graphic. Space requirements for menus would increase if menu
enhancements such as those seen on consumer DVDs were to be incorporated (high-end
graphics, motion and animation). The use of a generic menu graphic means that the same
DVD may be used by multiple airlines. Airline branding is accomplished with the image
that is imprinted on the front of the DVD.

IFE DVD Device: This is the term used by the airline industry to describe an Inflight
Equipment, DVD player. It is specifically manufactured to meet airline standards for
playing Region 8 coded discs and to be installed or distributed on aircraft.

Compression/Encoding: When a movie master is digitized, it is converted into bits of
data. This movie is now an incredibly large file of data, usually in the multi-gigabyte (one
byte equals 8 bits) range. Compression brings that file down to a manageable size for
storage and retrieval. Compression does not improve the picture and in most cases
actually lessens the quality. Encoding the data is essentially configuring the compression
to decode or playback within certain parameters. Compression is done with special
encoding computers that “watch” the movie and compare picture frames. Bits are added
when movement occurs (like a person walking or talking) or copied for stationary
objects, such as a tree in the background that doesn’t move between frames. Copying
reduces the number of bits required and thus compresses the file.

The compression is done to a definite specification such as MPEG 1 or MPEG 2 so that
any compatible playback system can read the compressed files. MPEG 1 was the first
approved standard for compression and the bit amount for a compressed movie is
substantially lower than for MPEG 2. MPEG 2 was developed in answer to a call for a
higher quality picture, such as with DVD. A one-hour movie in MPEG1 will fit on a CD
(600Megabytes) while an MPEG 2 movie will take 2-3 gigabytes.

Bit Rate: When you order a compressed movie for DVD or VOD, you must specify at
what bit rate the movie will play back. The higher the bit rate, the more bits it can read
per second, hence the better the picture will look because you are throwing more data at
the screen per second. A low bit rate MPEG 1 is around 1.2 Megabytes per second and
you can readily tell this is not high quality. As you move up the bit rate to say 1.5 or 1.6
there is definite improvement - not great, just better. MPEG 1 at bitrates of 1.5 and 1.6 is
used for VOD systems. The advantage of MPEG 1 and low bit rates is the relatively low
amount of space it takes on a computer/server and the more seats the movie can be
distributed to due to the size of the airline distribution system “pipeline” (which is not to
be confused with “bandwidth”). With servers continually improving and hard drives
getting cheaper and bigger, more airlines are exploring MPEG 2 for VOD, which requires
a higher bit rate and results in a higher quality product. Bit rates used for DVD typically
range from 4.5 to 6.0Megabytes per second (Mbps).

VBR: Variable Bit Rate. This means that the bitrate will vary from scene to scene. A
higher bit rate will be used when required to maintain high quality in intense action
scenes for example, while a lower bitrate will suffice in scenes with relatively little
motion. The bit rate number is the average. For DVD encoding MPEG 2 VBR is
generally used.
CBR: Constant Bit Rate. The bit rate does not vary from scene to scene and is constant
throughout the movie. CBR is important in airline VOD systems as variations could
overload the airline distribution system “pipeline.” CBR gives the authoring process more
control on the amount of data that can be included on a disc. By lowering the bit rate, a
movie over two hours in length with multiple languages and subtitles can be made to fit
within the parameters of a DVD5 (one side, one layer).

Muxing: Another way of saying multiplexing or integrating digital elements. Muxing is
bringing together the video, audio, and control data elementary streams into one encoded
file that can be played back by a decoder (player).

Authoring: After compression and encoding, all the elements (assets) must be
programmed to link together so that the DVD functions. The video, graphics, audio
tracks, subtitles and menus are authored (or programmed) and muxed into one cohesive
file. All the information the player and the viewer needs are programmed in at this time.
The final step is formatting so the replicator can simply load the file and build a glass
master for replication.

Content Scramble System: When the specification for DVDs was first developed, a key
requirement was for the secure and authorized playback of this digital content. The new
medium offered opportunities for dishonest distribution through downloading the
audio/video data files to a hard drive. A special method of encrypting the DVD discs to
prevent copying the DVD data files was developed. This is called CSS. See Encryption
below. Moved below encryption

Encryption: The data on a DVD is scrambled so that a computer DVD-ROM or other
DVD reader can’t access the audio and video files. In all DVD players there is a
descrambling circuit that decrypts the files and plays the content. The encryption key is
embedded in the DVD, which makes it impossible to copy or even play a copy of a DVD
because the player won’t be able to find the key on the copy.

Note: Secret Agent, the most popular encryption tool for airline entertainment systems,
is used primarily for VOD or scheduled viewing systems and not typically for DVD.

Metadata: This is like a digital program guide or “properties” file about the video. It can
include just about anything from the video title, running time, studio, etc., to identify the
video that you are accessing. The metadata typically does not reside on the video file but
may be loaded onto the server to provide file location and identification. Moved below.

Early Window Content: This refers to the date when movies are released for airline
overhead play dates, generally three months after the theatrical release date. Early
windows are reserved for limited markets such as hotel and airline entertainment systems
and certain territories. This content requires a higher level of security than the normal
consumer market as copying or pirating these titles will absolutely impact later releases
to home video, cable pay-per-view, overseas, etc.
Late Window Content: This refers to content that may have already been released in
other markets, including home video, and requires the same lower level of security
protection as the consumer market.

Head-End IFE: A Head-End Inflight Entertainment system is the equipment rack that
contains all the movies that are distributed to the seats. It resides on the aircraft in a place
accessible to the crew only. It is monitored by a trained flight attendant and updated by
the airline assigned personnel. It usually contains the movies, a computer programmed to
serve the movies to the passengers, a distribution system that sends the movies through
the cabling to the seat, and a monitor that informs the attendant of the system status.

Authoring and Navigation Requirements (Ref: 0598 paragraph 10)

The DVD was originally designed for home use; however, it has great potential for the
airline entertainment industry. A DVD is capable of holding up to 8 languages and 32
subtitles per side or layer. To access these features, you typically will use your remote
control, which has a language or menu feature, and pull up a screen on your TV that lists
the languages or subtitles. Using the up- or down-arrow features, you just go to the
language and press enter. When a movie is being authored for airline use, the lab will
program and mux the languages into the file. The first thing that will pop up when you
put the disc into the player is a menu with buttons listing, at least, the languages and/or
subtitles available on the DVD and a button to play the movie.

Some DVD players have inherent language selection buttons and that may be authored
into the disc. They may be accessed directly through the language selection button of the
remote control.

Security Requirements (Ref: 0598 paragraph 11)

According to 0598 spec, security of the DVDs is the responsibility of the airline and is
subject to approval by the content owner. Areas for concern include:
 Method of delivery to the distribution point
 Method of delivery to the aircraft
 Security of the DVDs while in use
 Accountability for the DVDs.
Early-release-content DVDs will require more extensive security, and this is not
addressed in detail in the 0598 specification. In any case, security measures for early
release should exceed those for late release unless the security for both is equal to early-
release security. (Same issues and liability just more secure media)

In the case of using DVD-ROMs for loading file servers on the aircraft, special
allowances must be made to allow for the transfer of data files to the server. If using late
window content, the DVD cannot have CSS. The CSS (Content Scrambling System)
prevents the copying of DVD data files onto a computer drive.
There may be content that is exempt from the early- or late-window security
requirements, such as shorts, special programming, etc., in which case it may be perfectly
all right to load from a DVD-ROM without CSS. The security protocol for late- and
early-release content DVDs requires that they will always have CSS or better security on
the disc and therefore cannot be downloaded.

Early-release DVD security protocol requires that the players must not easily be removed
from the aircraft and must undergo stringent handling procedures as developed by the
airline and approved by the content owners. The security for early release is different
from the general consumer market as only those players specifically manufactured for the
airline entertainment systems will be able to descramble the DVD encryption.

Regions: All DVDs are encoded to play in certain geographic regions. Players sold in
those regions are equipped to play DVDs encoded for that region only. For example,
Region 1 (US primarily) discs will not play on players from Europe, Asia or other
regions. In some instances where playback security is not an issue, a DVD may be
encoded as “all region.”

Region 8: Region 8 has been designated by the industry specifically for the airline
market. All DVD players manufactured for the airline market are coded as Region 8 only.
All airline DVDs, either early or late release, must carry a Region 8 code so the DVDs
will play only in Region 8 players and won’t work in home players. The region 8 code is
added during the authoring process. If the content owner wants to permit wider use, other
region codes may be added. For instance a disc coded for region 1 and 8 will play the
disc on both a region 1 consumer player (US primarily) and on aircraft (region 8), but not
on European, Asian or other consumer players.

All-Airline Generic IFE DVD Discs (Ref: 0598 paragraph 14.3)

It is strongly encouraged that DVD content does not carry an airline logo or other
branding. This would allow for a wider use of the DVD master and possibly some cost
savings. The premise behind this is there may be several airlines using the same movie,
short, or informational piece. Without specific airline branding, the same DVDs may be
used for each participating airline. They may still carry the same security features such as
CSS but there would not be an airline logo or other branding on the menu screens or any
airline specific treatments. Airline branding may be achieved via the silk screen imprint
on the DVD itself, by labeling, and/or in the DVD packaging.

Informative Annexes (Ref: paragraph 15.)

The following are interpretations of some of the additional explanatory notes contained
in the 0598 spec.

Disc Labeling. In order to convince the passenger/user of the DVD that these are not
typical DVDs, the label should warn them that these are not playable in their home DVD
player. It may also discourage the user from removing the DVD from the aircraft.
DVD Device Configuration Methodology (Ref: paragraph 15.2)

DVDs authored for consumer players may have certain control features that would not be
available on an aircraft IFE DVD device. It is suggested that when authoring IFE DVDs
these features (including remote control features) be left out.

Default Audio (Ref: paragraph 15.2.1), Default Menu Language (paragraph 15.2.4)

It is possible to access languages on a DVD without going through the menu-by-language
settings within the disc. They may be set to primary and secondary languages or audio. It
is recommended that the internal language setting be set to the airline primary language.
In other words, if the primary language is French, then the default internal primary
language should be French. This is done in the authoring process and is not set by the
passenger or crew.

Default Subtitle Language (Ref: paragraph 15.2.2)

Subtitles work the same way, with or without menus as per the default language settings
above. The “without” menu is the built-in DVD control feature. The authoring process
will make sure the primary subtitle language matches the primary airline language.
However, every effort should be made to avoid passenger access to this DVD control
feature since there can be conflict between the visible menu and the inactive menu.

Default Subtitle Display (Ref: paragraph 15.2.3)

This is another authoring process that is needed in order to “turn off” the internal subtitle
display control. The problem with an internal display is that it does not match the airline-
designed menu structure, may not represent the actual languages or subtitles or the
correct order of those elements. Turning this feature off prevents the passenger from
accidentally navigating through a disc and selecting languages or subtitles that may not
be on the disc.

Methodology For Warnings Regarding Region Code (Ref: paragraph 15.4)

DVD discs can be coded with more than one region code. So a late-release title coded for
the US as Region 1 can also be coded for the airlines as Region 8. Using some authoring
techniques, a unique version of the DVD can play when it recognizes one of the regions:
for example, a Region 1 disc may have coming attractions while the Region 8 may have a
travel short or airline commercial.

DVD Menus and Navigation Simplicity (Ref: paragraph 15.6)

Since airline DVDs are playing in special IFE DVD players, probably without a remote
control, and probably an abbreviated control panel, menus are designed for simple use.
Minimal buttons and interaction serve to allow the passenger an easy-to-understand
process.

This summary is intended to provide an interpretation of 0598 for users in non-
technical fields. It is not an official WAEA specification and, in any questions of
conflict, the true Specification 0598 will prevail.


Prepared by:          Cliff Hall, Lone Pine Digital
                      Janice Daniello, Post Modern Edit

				
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