1. MULTIMEDIA SERVERS, DRM and the MPEG-21 Standard
MULTIMEDIA SYSTEMS
IREK DEFEE

2. MULTIMEDIA HAS TWO BASIC REQUIREMENTS FOR STORAGE AND SERVERS:
- LARGE AMOUNT OF DATA STORED
(GIGABYTES FOR ONE ITEM)
- DATA OUTPUT IN (HIGH
BANDWIDTH) STREAMS
THIS IS CALLED STREAMING
MULTIMEDIA SYSTEMS
IREK DEFEE

3. STREAMING MEANS THAT EACH USER GETS CONTINUOUS DATA
STREAM, PRECISELY SYNCHRONIZED
IN TIME, FROM THE STORAGE AND
THE SERVER
THE STREAM CAN BE HIGH BANDWIDTH –
FOR EXAMPLE 1, 3, 4 Mb/s for TV, 6-10 Mb/s for HDTV
MULTIMEDIA SYSTEMS
IREK DEFEE

4. THIS PUTS HIGH DEMANDS FOR THE STORAGE AND SERVER SYSTEM:
Assume there are 100 users and each wants
to get a movie stream compressed to 3 Mb/s. This means total system output capacity should be 300 Mb/s.
This should be streaming capacity, that is 100 streams of 3 Mb/s, each flowing with constant packet flow and no breaks
MULTIMEDIA SYSTEMS
IREK DEFEE

5. MULTIMEDIA DATA REQUIRE LARGE STORAGE. EXAMPLE: MOVIE STREAM OF 4 Mb/s
FOR 2 HOURS NEEDS 3.6 GB STORAGE
100 MOVIES REQUIRE 360 GB
LARGE SYSTEM COULD HAVE E.G.
USERS WITH 1000 MOVIES,
A BIG SYSTEM IS NEEDED
HOW TO BUILD SUCH A SYSTEM?
MULTIMEDIA SYSTEMS
IREK DEFEE

6. FOR MULTIMEDIA MASS STORAGE
IS REQUIRED BUT DEVICES LIKE TAPE, CD, DVD ARE NOT SUITABLE BECAUSE THEY CAN OUTPUT ONLY
ONE STREAM AT A TIME
HARD DISCS ARE MORE SUITABLE
- STORAGE IS HIGH AND GROWING
- OUTPUT CAPACITY IS HIGH
MULTIMEDIA SYSTEMS
IREK DEFEE

7. IN STANDARD COMPUTER SYSTEMS STORAGE IS BASED ON HARD DISCS
WHICH ARE MECHANICAL DEVICES
THOUGH SEMICONDUCTOR DISKS
ARE AVAILABLE BUT EXPENSIVE
HARD DISC ARE ESSENTIALLY SERIAL IN NATURE SINCE THEY
HAVE HEADS WRITING AND READING ON A DISC PLATTER
MULTIMEDIA SYSTEMS
IREK DEFEE

8. CONSTRUCTION OF HARD DISC: MAGNETIC MATERIAL ON PLATTERS IS ARRANGED
IN TRACKS.
HEADS ARE READING/WRITING BY CHANGING
MAGNETIC ORIENTATION
MULTIMEDIA SYSTEMS
IREK DEFEE

9. HARD DISC CAN THUS OUTPUT ESSENTIALLY ONE OR FEW STREAMS
BUT WITH HIGH BANDWIDTH (OVER
100 MB/sec)
BECAUSE HARD DISC MECHANICAL PARTS MOVE VERY QUICKLY, HARD DISC CAN OUTPUT MANY STREAMS OF LOWER BANDWIDTH BUT OUTPUT CAPACITY WILL BE LIMITED
MULTIMEDIA SYSTEMS
IREK DEFEE

10. CURRENTLY SINGLE DISC DRIVES HAVE CAPACITY UP TO SEVERAL
TERABYTES (1 TB=1000 GB)
STREAMING CAPACITY IS IN THE
RANGE OF Mb/s STREAMS
OUTPUT CAPACITY DEPENDS ALSO ON - THE OPERATING SYSTEM,
- THE INTERNAL PC BUS AND
- I/O – RELATED TO NETWORKING
MULTIMEDIA SYSTEMS
IREK DEFEE

11. -STORAGE SIZE: TODAY IT IS 3 TB, GROWING
HARD DISC PARAMETERS:
-STORAGE SIZE: TODAY IT IS 3 TB, GROWING
1TB PER YEAR? (WE DO NOT KNOW WHEN IT WILL FINISH, NEVER?)
Platters rotational speed RPM
Interface – SATA - 3 Gb/sec and 6 Gb/sec
Sustained data transfer rates – 150 MB/s
Random read/write: 75/150 operations per second
Average data seek time – 6 ms writing 12 ms reading
MULTIMEDIA SYSTEMS
IREK DEFEE

12. THUS THE DESIGN OF STORAGE SYSTEM FOR MULTIMEDIA DATA
MUST TAKE INTO ACCOUNT LIMITS
ON STREAMING CAPACITY OF HARD
DISCS
STREAMING CAPACITY DEPENDS ON
- MECHANICAL PROPERTIES
- FILE SYSTEM ORGANIZATION
MULTIMEDIA SYSTEMS
IREK DEFEE

13. DISC HEAD MUST BE POSITIONED TO START READING, NECESSARYT HEAD
MOVEMENT WILL DEPEND ON THE LOCATION
OF A TRACK. AVERAGE TIME MIGHT BE
E.G´. 8MS.
WHEN HEAD IS POSITIONED IT CAN START
READING, THE SPEED CAN BE E.G. 100 MB/S
FOR STREAMS, ONE HAS TO READ AS MANY
HIGH BANDWIDTH STREAMS AS POSSIBLE.
E.G. 180 STREAMS WITH 3 Mb/s EACH
MULTIMEDIA SYSTEMS
IREK DEFEE

14. IN PRACTICE THERE WILL BE MANY
PARAMETERS IN THE DESIGN OF MEDIA SERVER
MEMORY BUFFERS
NETWORK INTERFACES
OPERATING SYSTEM
THEY NEED TO BE OPTIMIZED FOR
MAXIMUM PERFORMANCE
IN PRACTICE DISCS HAVE THEIR OWN RAM BUFFERS, AND THERE
ARE ALSO RAM BUFFERS IN
MEMORY PLUS
NETWORK INTERFACE BUFFER
MULTIMEDIA SYSTEMS
IREK DEFEE

15. EXAMPLE OF MEDIA SERVER DESIGN: SERVER BASED ON PC WITH SATA BUS
HARD DISC WITH 150 MB/s TRANSFER SPEED
NETWORK INTERFACE: GIGABIT ETHERNET 1000Mb/s
HOW MANY 4 Mb/S STREAMS IT CAN SUPPORT?
WE HAVE READING ACCESS LIMITED TO 75 /SEC
SO IT WILL BE ABOUT 75 STREAMS IN PRINCIPLE
PROCESSOR AND OPERATING SYSTEMS ARE ENOUGH FAST SO NO PROBLEM HERE
MULTIMEDIA SYSTEMS
IREK DEFEE

16. THUS, THE MEDIA SERVER PERFORMANCE MIGHT BE LIMITED BY VARIOUS
COMPONENTS OF PC SERVER ARCHITECTURE:
- HARD DISC PROPERTIES (READING STREAMS)
- BUS FROM HARD DISC TO COMPUTER (SATA)
NETWORK INTERFACE – E.G Mb/s
TO THIS ONE MAY ADD THE SPEED
OF PROCESSOR AND OPERATING SYSTEM
BUT THIS SHOULD NOT BE A PROBLEM
THE QUESTION IS: HOW TO INCREASE THE
HARD DISC STORAGE SPEED?
MULTIMEDIA SYSTEMS
IREK DEFEE

17. HERE WE SEE STANDARD COMPUTER ARCHITECTURE
IT COULD BE A PC WITH SATA HARD DISC
DEVICE INTERFACE PLUS PROCESSOR
IF WE CONNECT MORE DISCS, THIS WILL INCREASE
STORAGE SIZE BUT NOT ITS SPEED
WE NEED TO USE SOMETHING ELSE AND THIS IS... RAID ->
MULTIMEDIA SYSTEMS
IREK DEFEE

18. STRIPING AND RAID A METHOD FOR INCREASING STORAGE AND OUTPUT CAPACITY
IS BY CONNECTING HARD DISCS IN
PARALLEL AND STRIPING FILES
ON THEM
MULTIMEDIA SYSTEMS
IREK DEFEE

19. STRIPING AND RAID DISC DISC DISCF I L E S T R P N G
DISC
SYSTEM
DISC
CONTROLLER
DISC
THREE DISCS = THREE TIMES HIGHER OUTPUT
MULTIMEDIA SYSTEMS
IREK DEFEE

20. STRIPING MEANS THAT FILES ARE READ AND WRITE IN BLOCKS WHICH
ARE DISTRIBUTED OVER DISCS
EXTERNALLY THE SYSTEM WILL LOOK LIKE ONE BIG DISC
WITH N DISCS WE COULD HAVE N
TIMES HIGHER OUTPUT CAPACITY
AND N TIMES BIGGER STORAGE
MULTIMEDIA SYSTEMS
IREK DEFEE

21. STRIPING PRINCIPLE BLOCKS OF DATA ARE STRIPED AMONG DIFFERENT DISCS
OPERATING IN PARALLEL
IN THIS WAY SPEED OF READING
AND WRITING CAN BE INCREASED
MULTIMEDIA SYSTEMS
IREK DEFEE

22. THERE IS ONE ADDITIONAL IMPORTANT ADVANTAGE:
WITH THE INCREASING STORAGE
RELIABILITY IS GOING DOWN
WITH STRIPING ONE CAN BUILT-IN
ERROR TOLERANCE
THIS CONCEPT IS CALLED RAID =
REDUNDANT ARRAY OF
INEXPENSIVE DISCS
MULTIMEDIA SYSTEMS
IREK DEFEE

23. RAID F I L E S ADDED DISCS FOR PARITY T ERROR CONTROL R DISC P N G
CORRECT.
DISC F I L E S T R P N G
ADDED DISCS FOR
ERROR CONTROL
PARITY
DISC
DISC
SYSTEM
DISC
CONTROLLER
DISC
MULTIMEDIA SYSTEMS
IREK DEFEE

24. RAID DISC ARRAYS ARE CLASSIFIED IN SEVERAL LEVELS
RAID 1 - DISC MIRRORING (EACH
DRIVE IS DOUBLED)
RAID 2 - BIT INTERLEAVING AND
PARITY/ERROR CORRECTION
RAID 3 - BIT INTERLEAVING WITH
XOR PARITY – SINGLE DRIVE
DEDICATED TO PARITY
MULTIMEDIA SYSTEMS
IREK DEFEE

25. RAID 4 – BLOCK INTERLEAVING RAID 5 – BLOCK INTERLEAVING WITH PARITY
DISTRIBUTION
RAID 6 – FAULT TOLERANT SYSTEM
DISC FORM A MATRIX FOR ROW AND COLUMN PARITY – FAULTY DISC CAN BE IDENTIFIED AND REPLACED
RAID 7 – HETEROGENOUS SYSTEM
SUPPORTS MULTIPLE HOSTS
MULTIMEDIA SYSTEMS
IREK DEFEE

26. OVERALL ARCHITECTURE OF MACHINE WITH RAID DISC ARRAY AND NETWORK
ADAPTERS
RAID CAN BE IMPLEMENTED IN SOFTWARE
OR IN HARDWARE
HARDWARE RAID WILL PUT LESS LOAD
ON THE PROCESSOR AND SYSTEM
MULTIMEDIA SYSTEMS
IREK DEFEE

27. DISC ARRAYS CAN BE BUILT WITH TENS OF TERABYTES.
THUS ENOUGH STORAGE CAPACITY EXISTS FOR STORING VERY LARGE COLLECTIONS OF MULTIMEDIA DATA
MULTIMEDIA SYSTEMS
IREK DEFEE

28. HOW TO BUILT LARGE MEDIA SERVERS? IMAGINE A SYSTEM
SERVING ONE CITY WITH HUNDREDS, THOUSANDS, MORE USERS
FROM SUCH SERVERS THE REQUIRED
OUTPUT CAPACITY WOULD BE MANY GIGABITS/SEC, E.G x4Mb/s=40Gb/s
NO STANDARD COMPUTER HAS SUCH
OUTPUT
MULTIMEDIA SYSTEMS
IREK DEFEE

29. DESIGN OF MEDIA SERVER IS
DIFFERENT FROM STANDARD SERVER BECAUSE STREAMS MUST
HAVE GUARANTEED DELIVERY,
THAT IS STREAMS CAN NOT SLOW
DOWN OR STOP.
THUS, MEDIA SERVERS MUST BE
DESIGNED FOR THE PROJECTED
NUMBER OF USERS
MULTIMEDIA SYSTEMS
IREK DEFEE

30. WE CAN USE MANY SERVERS INSTEAD OF ONE
CREATING A SERVER FARM OR “CLOUD”
WE CAN USE RAM MEMORY BUFFERING CACHE FOR STREAMS – FROM THE RAM CACHE WE CAN SERVER MORE STREAMS THAN FROM HARD DISC
MULTIMEDIA SYSTEMS
IREK DEFEE

31. DISC SOMETIMES APPLICABLE
SOMETIMES WE CAN APPLY MULTICASTING IN WHICH MANY USERS GET THE SAME STREAM – ONLY A SINGLE STREAM IS RETRIEVED FROM HARD
DISC SOMETIMES APPLICABLE
MULTIMEDIA SYSTEMS
IREK DEFEE

32. WE SHOULD TAKE INTO ACCOUNT THAT MANY USERS MAY RETRIEVE
WE COULD ALSO DISTINGUISH BETWEEN PEAK DEMAND AND AVERAGE DEMAND FOR STREAMS, E.G. AVERAGE DEMAND CAN BE 10%
OF PEAK
WE SHOULD TAKE INTO ACCOUNT
THAT MANY USERS MAY RETRIEVE
THE SAME CONTENT ( PERHAPS DELAYED SLIGHTLY IN TIME)
MULTIMEDIA SYSTEMS
IREK DEFEE

33. MEDIA SERVER DESIGN: RAID STORAGE STORAGE BUS E.G. SATA III P... ...P
DATA FROM STORAGE ARE TRANSFERRED
TO RAM BUFFERS AND THEN TO NETWORK
INTERFACE
THE BIGGER THE RAM BUFFER, THE MORE
STREAMS COULD BE SUPPORTED BY THE
SERVER BUT IT WILL TAKE MORE TIME TO
FILL THE BUFFER SO THE START OF
CONTENT WOULD BE DELAYED.
THUS RAM BUFFERS CAN NOT BE TOO
BIG IN PRINCIPLE.
BUT ONE CAN TRY TO OPTIMIZE THE
SYSTEM CREATING BIGGER BUFFERS
WHEN SYSTEM IS NOT LOADED MUCH
AND SHORTER BUFFERS WHEN THERE
IS HIGH LOAD.
OVERALL SERVER OPTIMIZATION MIGHT
BE STILL AN OPEN PROBLEM
(OR COMERCIAL SECRETS ARE HERE?)
RAID STORAGE
STORAGE BUS
E.G. SATA III
PCIe
BUS
P P
PROCESSOR(S)
RAM BUFFERS
NETWORK INTERFACE
WITH BUFFER
MULTIMEDIA SYSTEMS
IREK DEFEE

34. ONE IDEA IS TO DESIGN SPECIAL BIG MACHINE WITH VERY MANY BUSES,
PROCESSORS, AND CONNECTED TO
BROADBAND NETWORK, WE SHOULD
TAKE INTO ACCOUNT THAT NETWORK
BANDWIDTH FROM COMPUTERS IS
LIMITED, E.G. GIGABIT ETHERNET IS
FASTEST PRACTICAL INTERFACE TODAY,
1000 Mb/s THOUGH SEVERAL SUCH INTERFACES
CAN BE USED AND THERE IS ALSO 10 Gb/s
INTERFACE
THUS, A BIG MACHINE WOULD NEED
TO HAVE MULTIPLE NETWORK INTERFACES
IT WOULD BE VERY EXPENSIVE
MULTIMEDIA SYSTEMS
IREK DEFEE

35. SUCH DEDICATED MACHINES WOULD REQUIRE: - MULTIPROCESSING
- MULTIPLE I/O TO THE NETWORK
- VERY BIG DISTRIBUTED STORAGE
MACHINE WOULD BE VERY EXPENSIVE AND NON-STANDARD
MULTIMEDIA SYSTEMS
IREK DEFEE

36. IN THE DESIGN OF MEDIA SERVERS THERE ARE TWO CHOICES
THE REAL DIFFICULT PROBEM IS WHEN MANY DIFFERENT STREAMS NEED TO BE RETRIEVED AND SEND
IN THE DESIGN OF MEDIA SERVERS
THERE ARE TWO CHOICES
DEDICATED MACHINES
MULTIPLE SYSTEMS WITH
CENTRAL CONTROL
MULTIMEDIA SYSTEMS
IREK DEFEE

37. EXPENSIVE AND NON-STANDARD
DEDICATED MACHINES
- MULTIPROCESSING
- MULTIPLE I/O
- DISTRIBUTED STORAGE
EXPENSIVE AND NON-STANDARD
MULTIMEDIA SYSTEMS
IREK DEFEE

38. ANOTHER IDEA: MULTIPLE STANDARD MACHINES
ANOTHER IDEA: MULTIPLE STANDARD MACHINES. MEDIA FILES ARE DISTRIBUTED ALONG A NUMBER OF SERVERS WHICH HAVE COMMON CONTROL
HERE THE PROBLEM IS THAT STORAGE
REQUIRED MIGHT BE BIGGER (OFTEN USED
MEDIA STREAMS ON MANY SERVERS
MULTIMEDIA SYSTEMS
IREK DEFEE

39. MULTIPLE SIMPLE MACHINES WOULD BE MUCH CHEAPER THAN
A SINGLE BIG SERVER. SINGLE
MACHINES CAN BE LOCATED NEAR
USER LOCATIONS.
FOR EXAMPLE, SINGLE SERVER WITH GIGABIT INTERFACE COULD
SERVE ABOUT 200 USERS, ONE WOULD NEED A HUNDRED OF SUCH
SERVERS FOR USERS
MULTIMEDIA SYSTEMS
IREK DEFEE

40. HOWEVER, THEN EACH SERVER WOULD NEED TO HAVE STORAGE WITH ALL MEDIA
BASIC IDEA
FOR MANY
SIMPLE SERVERS
HOWEVER, THEN EACH SERVER WOULD
NEED TO HAVE STORAGE WITH ALL MEDIA
FILES, SO OVERALL THERE WOULD BE
MUCH MORE STORAGE NEEDED THAN IN
A SINGLE BIG SERVER
MULTIMEDIA SYSTEMS
IREK DEFEE

41. ANOTHER CONCEPT – MULTIPLE SERVERS CONNECTED VIA NETWORK. THE NETWORK
CAN BE UED FOR FILE TRANSFER BETWEEN
SERVERS. STORAGE CAN BE ADAPTED FOR
THE DEMAND (ONLY POPULAR STREAMS WOULD
BE ON MORE SERVERS, SAVING STORAGE)
MULTIMEDIA SYSTEMS
IREK DEFEE

42. YET ANOTHER SYSTEM: STORAGE AND SERVERS ARE SEPARATED, THEN SERVERS
WILL BUFFER AND REPLICATE STREAMS
WHICH ARE IN DEMAND
MULTIMEDIA SYSTEMS
IREK DEFEE

43. SUCH SYSTEMS CAN BE ASSEMBLED QUITE EASILY BUT REQUIRE
- USER MANAGEMENT
- STREAM MANGEMENT
- CONTENT MANAGEMENT
- OVERALL PERFORMANCE
OPTIMIZATION
THIS HAS TO BE COORDINATED WITH
NETWORKING
MULTIMEDIA SYSTEMS
IREK DEFEE

44. IN FACT MEDIA SERVER IS MUCH MORE THAN
JUST SENDING STREAMS: USERS WILL
CONNECT/DISCONNECT, SEARCH APPLICATIONS
ALL THIS NEEDS TO BE MANAGED.
THERE WILL BE MANY CONTROL FLOWS
MULTIMEDIA SYSTEMS
IREK DEFEE

45. THE SYSTEMS WILL OFTEN REQUIRE PAYING,
THUS EXTENSIVE DATABASE OF USERS,
PAYMENTS, BILLING, AUTHORIZATION,
AUTHENTICATION WILL BE NEEDED.
ENCRYPTION OF DATA WILL BE NECESSARY
MULTIMEDIA SYSTEMS
IREK DEFEE

46. IF USERS HAVE ACCESS TO BROADBAND NETWORK OTHER APPLICATIONS MIGHT
BE ATTRACTIVE: WEB ACCESS, OWN BROADCAST,
VIDEOTELEPHONE, VIDEO CONFERENCING
MULTIMEDIA SYSTEMS
IREK DEFEE

47. ON THE OPERATOR SIDE, FULL ADMINISTRATION IS NEEDED:
SYSTEM OPERATION MONITORING
ADMISSION CONTROL (NEW USERS)
CONTENT UPDATES
MULTIMEDIA SYSTEMS
IREK DEFEE

48. MEDIA SERVERS ARE ESSENTIAL COMPONENT OF MULTIMEDIA SYSTEMS
CONCLUSIONS:
MEDIA SERVERS ARE ESSENTIAL
COMPONENT OF MULTIMEDIA SYSTEMS
THEY DESIGN NEEDS TO TAKE INTO
ACCOUNT STREAMING GUARANTEES
STORAGE, NETWORKING, PROCESSOR
REQUIREMENTS ARE QUITE SUBSTANTIAL
LARGE SOFTWARE IS NEEDED FOR
COMPLETE COMMERCIAL SYSTEMS
MULTIMEDIA SYSTEMS
IREK DEFEE

49. DIGITAL RIGHTS MANAGMENT

50. What is missing? WHAT IS MISSING IN THIS PICTURE? The missing part is
Here we see scheme of networked multimedia system, red part is
hardware, blue is content, green is software for running it.
WHAT IS MISSING IN THIS PICTURE?
The missing part is
CONTENT PROTECTION AND DRM

51. DIGITAL CONTENT (AUDIO,
VIDEO, GRAPHICS, IMAGES)
CAN BE EASILY COPIED, TRANSMITTED AND DISTRIBUTED
THIS HAS GREAT ADVANTAGES AND
BUSINESS POTENTIAL

52. BUT DIGITAL MEDIA CAN ALSO MAKE BIG PROBLEMS FOR CONTENT OWNERS DUE TO UNAUTHORIZED USE. THEY CAN EASILY LOSE THEIR PROPERTY
CONTENT OWNERS NEED THUS STRONG PROTECTION

53. THUS DIGITAL CONTENT SHOULD
BE PROTECTED AGAINST
UNAUTHORIZED USE
THIS PROBLEM IS KNOWN CURRENTLY
UNDER THE NAME DRM
DIGITAL
RIGHTS
MANAGEMENT

54. Digital Rights Management (DRM)
= technologies used by publishers or copyright owners to control access to or usage of digital data or hardware, and to restrictions associated with a specific instance of a digital work or device
can be used
to protect high-value digital assets
control their distribution and usage
Ultimate goal:
persistent content protection against unauthorized access to the digital content, limiting access to only those with the proper authorization
to manage usage rights for different kinds of digital content (e.g.music files, video streams, digital books, images)
different platforms (e.g. PCs, laptops, PDAs, mobile phones)
control access to content delivered on physical media or any other distribution method (e.g., CD-ROMs, DVDs)
Essential to the content whuch production requires huge amount of money, but can be copied in a second

55. Digital Rights Management (DRM)
Different methods for
Audio
Video
Internet stores
Documents (Enterprise DRM)
Digital licenses
the consumer purchases a license with certain rights
A license is a digital data file that specifies certain usage rules (frequency of access,expiration date, restriction of transfer to other devices, copy permission etc., may combined to try-before-buy) for the digital content
Several players involved in
E.g. online distribution:
content provider, distributor,
consumer, clearing house
DVD’s manufacturer, replicator, player…
Consumer: privacy, fair use (research, education..), usability (compatibility, seamless, updates)
Essential to the content whuch production requires huge amount of money, but can be copied in a second

56. EXAMPLE: Apple music store
Buying music from the
network means that the
content has to be protected
against copying

57. WHAT ARE THE REQUIREMENTS FOR DRM?
IT SHOULD PREVENT COPYING
IT SHOULD AUTHORIZE ACCESS
LIMITED TO: PARTICULAR USER,
SPECIFIC TIME, SPECIFIC NUMBER
USAGE AND COPIES, ETC.
IT SHOULD FACILITATE PAYMENT
FOR CONTENT (E.G. RENEWAL OF
RIGHTS)

58. ALL REQUIREMENTS FOR DRM ARE VERY DIFFICULT TO SATISFY
IN PARTICULAR THEY ARE DIFFICULT IF THE DRM SYSTEM WOULD BE STANDARDIZED, THAT IS
IS STRUCTURE IS KNOWN
THIS IS BECAUSE STANDARDIZED SYSTEM MIGHT BE EASIER TO BREAK THAN SECRET SYSTEM

59. IN PRINICPLE DIGITAL CONTENT CAN BE EASILY (?) PROTECTED
BY ENCRYPTION
WHAT IS ENCRYPTION?
THE CONTENT BITS ARE MANIPULATED IN SECRET WAY
BY SOME ALOGRITHM.

60. THE ORIGINAL BITS CAN BE RECOVERED BY REVERSING THE OPERATION OF THE
ALGORITHM
CONTENT
ENCRYPTION
ALGORITHM
DECRYPTION
ALGORITHM
CONTENT

61. BUT SUCH SYSTEM HAS PROBLEMS
IF ALGORITHM IS KNOWN,
EVERYBODY WILL USE IT
HOW TO CONTROL ACCESS?
THAT IS USERS MAY BUY ACCESS
FOR SOME TIME AND FOR SOME
CONTENT ONLY
WHAT TO DO WITH USERS WHICH
WILL USE PROPER ACCESS FOR
ILLEGAL COPYING?

62. THUS THE DRM CONTENT PROTECTION MUST BE MORE CLEVER IT HAS TO BE BASED ON
CONDITIONAL ACCESS
ENCRYPTION ALGORITHMS
and the newest addition is:
3. REVOCATION OF RIGHTS

63. WHAT IS CONDITIONAL ACCESS? IT IS ACCESS GIVEN ON LIMITED
CONDITIONS, E.G. TIME, CONTENT,
PAYMENT
CONDITIONAL ACCESS
CONTENT
ENCRYPTION
ALGORITHM
DECRYPTION
ALGORITHM
CONDITIONAL ACCESS CAN BE A CARD GIVEN
TO THE USER, OR CERTIFICATE SEND VIA
INTERNET

64. EXAMPLE – THE SYSTEM USED IN
DIGITAL TELEVISION FOR WATCHING PAY PROGRAMS
IN THIS SYSTEM CA HAS A FORM
OF SUBSCRIPTION CARDS
HOWEVER, THERE ARE SEVERAL
ENCRYPTION ALGORITHMS USED.
FOR DECRYPTION, THERE ARE
DIFFERENT HARDWARE CAM’s
CONDITIONAL ACCESS MODULES

65. RECEIVER FOR DIGITAL TELEVISION
CAM MODULE
SUBSCRIPTION CARD

66. ONE RECEIVER CAN HAVE SEVERAL CAM’s FOR RECEIVING
PAY PACKAGES WITH DIFFERENT
SUBSCRIPTION CARDS. SUCH SYSTEMS ARE WIDELY USED IN TELEVISION.
BUT MANY SYSTEMS WERE ALSO
BROKEN SINCE ONE CAN ANALYZE
PROGRAM ON THE CARD AND TRACE TRAFFIC BETWEEN
CARD AND CAM.

67. BUT WHAT TO DO IF A USER HAS
VALID SUBSCRIPTION BUT USES
IT FOR RECORDING AND DISTRIBUTING CONTENT ILLEGALLY?
ONE SOLUTION IS TO PREVENT
RECORDING AND/OR TO PREVENT
GETTING THE RECORDING OUT
OF THE DEVICE

68. IN MEDIA TERMINAL USER CAN
RECORD DIGITAL TV PROGRAMS
ON INTERNAL HARD DISC
BUT RECORDED CONTENT IS
ENCRYPTED AND THERE IS NO
WAY OF GETTING IT OUT OF THE
TERMINAL

69. REVOCATION OF RIGHTS
Revocation means that grants given once
are removed from the user who breached the contract.
We shall explain revocation on the new
example of High Definition DVD discs
a system called Blue Ray

70. Current DRM systems for DVD
Legacy Format
Advanced Format
Standard Definition
High Definition
CSS
= Content Scramble System
AACS
= Advanced Access Content System
DVD
Blu-ray Disc
Other
formats
OTHER FORMATS:
- FOR AUDIO: Pre-recorded audio CPPM (56-bit key)
DVD Content
Protection is
broken
HD BR is a new system with much
improved protection and
REVOCATION

71. Content Scramble System (CSS) Protection for DVD
A data encryption and authentication scheme to prevent copying video files from the disks
Several keys included in: authentication key, disc key, player key, title key, second disk key set, and/or encrypted key
a weak 40-bit stream cipher algorithm
Brute Force Attact, possible to find the keys, only 2^40 options, attacts to the hash codes
Published 1996, but only usable in licensed DVD playbacks (Windows, MAC), not in Linux
 1999 DeCSS

72. Advanced Access Content System (AACS) for HD BLUE RAY
= a standard for content distribution and digital rights management, intended to restrict access to and copying of the next generation of optical discs and DVDs.
“ a specification for managing content stored on the next generation of prerecorded and recorded optical media for consumer use with PCs and CE devices. “
“will complement new innovations in the next-generation of optical discs, and enable consumers to enjoy next-generation content, including high-definition content.”
The specification released in April 2005
In addition to the general objectives described in the Introduction and Common Cryptographic Elements book
of this specification, the use of AACS for protecting pre-recorded video content was designed to meet the
following specific criteria:
• Provide robust protection for both off-line playback and optional enhanced uses enabled via on-line
connection.
• Provide for extended and extensible usage (e.g. jukebox storage, pay for copy).
• Independent of physical storage format to the degree possible.
• Compliant players can authenticate that content came from an authorized, licensed replicator.
AACS is designed to meet the following general criteria:
• Meet the content owners’ requirements for robustness and system renewability
o Content encryption based on a published cryptographic algorithm.
o Limit access to protected content to only licensed compliant implementations.
o Support revocation of individual compromised devices’ keys.
o Limit output and recording of protected content to a list of approved methods.
• Suitable for implementation on both general-purpose computer and fixed-function consumer
electronics platforms.
• Applicable to both audio and video content, including high-definition video.
• Applicable to various optical media formats.
• Transparent to authorized use by consumers.
To meet these general objectives, AACS is based in part on the following technical elements:
• Robust encryption of protected content using the AES cipher.
• Key management and revocation using advanced Media Key Block technology.

73. AACS – Design criteria
Meet the content owners’ requirements for robustness and system renewability
Content encryption based on a published cryptographic algorithm.
Limit access to protected content to only licensed compliant implementations.
Support revocation of individual compromised devices’ keys.
Suitable for implementation on both general-purpose computer and fixed-function consumer electronics platforms.
• Applicable to both audio and video content, including high-definition video.
• Applicable to various optical media formats.
• Transparent to authorized use by consumers.
Basic technical elements:
Robust encryption of protected content using the AES cipher.
Key management and revocation using advanced Media Key Block technology.

74. AACS - Usage Scenarios Compared to CSS: + Legal copies
+fexibility to use

75. AACS : Content validation and revocation
Content Owner
Licenced Player
Content Owner
Licensed Players will contain the Entity Public Keys that will be used as the root of trust for validating content
signatures. Media containing content signed in accordance with this scheme will contain the following items:
• Content Certificate
• Content Hash Table
• Content Revocation List
The Content Certificate and Content Hash Table
 Validate the the authenticity of the content
 prevent playback of that content if the signature is not valid.
The Content Revocation List
 prevent playback of content that contains a valid signature but is not valid content.
The Content Certificate, Content Hash Table, and Content Revocation List must be stored on the pre-recorded
media with the signed content.
Licensed replicators shall include with any Certified Content that they produce, a signed Content Certificate
covering that content.
Licensing Entity

76. AACS: System overview – pre-recorded video
CONTENT OWNER
SERVCE PROVIDER
Content
Usage rules
Enhanced uses enabled via
online authentication
PRE-RECORDED VIDEO
Title keys
- Encrypted content
- Usage rules of content
Content certificate
Content hash
Device revocation data [MKB]
Content revocation list [CRL]
Sequence key block
LICENCED REPLICATOR
LICENCED PLAYER
Device revocation data
[MEDIA KEY BLOCK]
Content revocatio list [CRL]
Content sertificate
Sequence Key Block
Secret keys
Device keys
(unique for the device /application)
Entity public keys
(to check the content revocation data and content sertificate)
CONTENT OWNER:
+ provides AV content
+ usage rules
+ title keys
LICENSING ENTITY  LICENCED REPLICATOR
+ DEVICE REVOCATION DATA = MEDIA KEY BLOCK
+ MKB enable players using own device keys to calculate the MEDIA KEY
+ If the keys hackered ´the old keys can be revoked by new MEDIA KEY BLOCK
+ CONTENT REVOCATION LIST
= identifies the sign content with valid certificate,
but has later on revoked and should not be accessed by compliant player
+ CONTENT SERTIFICATE
= for content identifying, including cryptographic hash collection
+ SEQUENCE KEY BLOCK
+ SECRET KEYS based on device variation and media key
LICENCED REPLICATOR
+ encrypts the content
+ TITLE KEY – content with media key information
- contains the USAGE RULES OF THE CONTENT
 uses several secret keys  called TITLE KEYS (for playback you need to know several title keys)
Media keys differes between the movies a lot
+ all other information stored on storage medium
LICENSING ENTITY  LICENCED PLAYER
+ DEVICE KEYS (unique for devices and applications)
- needed to encrypt the device revocation data
+ ENTITY PUBLIC KEYS
 used to check the CONTENT REVOCATION DATA and CONTENT CERTIFICATE
PLAYER
+ uses DEVICE KEYS to check the compatibility to MEDIA KEY BLOCK, to calkulate media key form media key block
+ based on MEDIA KEY + SEQUENCE KEYS  SKB (Sequence Key Block)  Media key variant
+ TITLE KEY to check to provide the compliant playback
+ CRL
+ compliant player keeps the CRL in non-volatile storage, unless it already has a more up-to-date list.
+ Using the most up-to-date CRL, the player checks to see if the content is revoked, and if it is, access is aborted.
+ During playback, the compliant player calculates a series of content hashes using the same method used by the
replicator. Replicators and player’s hashs needs to match.
ENHANCED USES ENABLED VIS ONLINE AUTHENTICATION
+ For example, a home video server might connect with a service provider to obtain authorization to make a protected local copy of a given pre-recorded Title for “jukebox”
purposes.
- authorization  free-of-charge to the owner of the optical media
- Thus, this and other enhanced uses may entail business
interaction between content owners and service providers, as indicated by the dashed line in the figure above.
LICENSING ENTITY

77. AACS: Content encryption and decryption

78. AACS: Revoking the keys – in practice
In practice the operation of revocation in AACS is as follows:
- Each content (e.g. movie disc) release gets special key
Each type of player (hardware and software) gets special key
Now let’s think that somebody has broken protection of this
movie disc and released illegal copies or has modified player so
it can play illegally the content.
Then those discs and players will be put on the revocation list.
The list is updated on all new discs, so the when new disc is
played on the player, playback of the broken disc will be disabled
or the player is disabled!
+ IN FEB. 128-bit string of handful numbers and digits was published on websites
 The websites were ask to be taken off  now in you tube in T-shirts
+ Just one of the several needed keys, but it compromises the part of AACS
UNIQUE MACHINE SPECIFIC KEYS OF HW COMPANIES  USED FOR PLAYERS
COMMON KEYS FOR THE SOFTWARE  CAN BE USED IN EVERY COPY OF THE PROGRAM VERSION
THE RELEASED key was a COMMON KEY FROM Cyberlink corp and Intervideo
AACS ASKED
1. SOFWARE COMPANIES TO REVOKE THE RELEASED KEY IN 2 WEEKS
- Lots of work. E.g. PC stores have lots of PC’s and Laptop’s where the programs are installed as default
2. NEW MEDIA KEY BLOCK for HD DVD MANUFACTURERS
 New disks on markets this month
 Customers not able to play any disks released after may 2007 until the sofware versions are released
THERE MIGHT BE CUSTOMERS SAYING THAT THEIR CD DOES NOT PLAY

79. AACS: Revoking the keys – in practice
Feb bit string of keys was published
Compromises the part of AACS
Common keys for software players (Cyberlink, Intervideo)
Revocation started
HD DVD’s with New Media Block’s on markets in May
 Customers not able to play any disks released after may 2007 until the sofware versions are released
- Sofware updates = lots of work, not available yet?
+ IN FEB. 128-bit string of handful numbers and digits was published on websites
 The websites were ask to be taken off  now in you tube in T-shirts
+ Just one of the several needed keys, but it compromises the part of AACS
UNIQUE MACHINE SPECIFIC KEYS OF HW COMPANIES  USED FOR PLAYERS
COMMON KEYS FOR THE SOFTWARE  CAN BE USED IN EVERY COPY OF THE PROGRAM VERSION
THE RELEASED key was a COMMON KEY FROM Cyberlink corp and Intervideo
AACS ASKED
1. SOFWARE COMPANIES TO REVOKE THE RELEASED KEY IN 2 WEEKS
- Lots of work. E.g. PC stores have lots of PC’s and Laptop’s where the programs are installed as default
2. NEW MEDIA KEY BLOCK for HD DVD MANUFACTURERS
 New disks on markets this month
 Customers not able to play any disks released after may 2007 until the sofware versions are released
THERE MIGHT BE CUSTOMERS SAYING THAT THEIR CD DOES NOT PLAY
RESPONSE TO REPORTS OF ATTACKS ON AACS TECHNOLOGY
April 16, AACS LA Announces Security Updates (Updated URLs)
In response to attacks against certain PC-based applications for playing HD DVD and Blu-ray movie discs, Advanced Access Content System Licensing Administrator, LLC (“AACS LA”) announces that it has taken action, in cooperation with relevant manufacturers, to expire the encryption keys associated with the specific implementations of AACS-enabled software.
Consumers can continue to enjoy content that is protected by the AACS technology by refreshing the encryption keys associated with their HD DVD and Blu-ray software players. This refresh process is accomplished via a straightforward online update.
Through this online update process, manufacturers are also able to see that consumers update their player implementations prior to distribution of encryption key expiration information via new movie discs.
Consumers are advised to check with the manufacturer of their AACS-enabled Blu-ray or HD DVD PC-based player to make sure you have installed the latest version. The following manufacturers have provided links to provide relevant information and facilitate consumer updating of their players:
InterVideo – publishers of WinDVD products
CyberLink – publishers of PowerDVD products
February 15, 2007
Regarding the reported attacks on 2/13/2007, AACS has confirmed that an additional key (called a “processing key”) has been published on public websites without authorization. This is a variation of the previously reported attack (a compromise of a specific implementation) on one or more players sold by AACS licensees. Although a different key was extracted, this represents no adverse impact on the ability of the AACS ecosystem to address the attack. All technical and legal measures applicable to the previously reported attack will be applicable against this attack as well.

80. Summary
DMR
= technologies used by publishers or copyright owners to control access to or usage of digital data or hardware, and to restrictions associated with a specific instance of a digital work or device
to protect high-value digital assets
control their distribution and usage
AACS
Cross-industry collaboration to facilitate next generation content distribution
Enables new, flexible ways to enjoy content while protecting copyrighted works
Technical specifications and licensing
RELEASE OF KEYS IN FEB 2007
+ On websites  AACS players put down
+ YouTube
+ a "processing key," an 128-bit string represented by a handful of numbers and digits.
+ By itself an individual processing key is no major threat.
+ It is just one of several keys needed as part of a cryptographic process to unlock content on an HD DVD or Blu-Ray HD disk.
+ Nevertheless, the public release of a key does compromise part of a system developed by the Advanced Access Content System (AACS),
+ a consortium of content and systems companies that defined the security for HD disks.
+ Once the key was in the clear, AACS started a process of revoking it.
TWO TYPE OF KEYS:
+ Unique keys  hardware companies to use in HD players, belongs to spesific machine
+ Common keys  software players to be used in the every copy of a program of the given version
+ keys on HD disks
In cryptographic process all these keys are used to unlock the content on a disk.
THE RELEASED KEYS WERE COMMON KEYS SOFTWARE COMPANIES, CyberLink Corp. And InterVideo
AACS  RELESED KEYS TO BE REVOKED
+ new versions of software has to be released in two weeks with new keys!
+ software companies (Cyberlink and Intervideo) need to inform
+ their partners e.g. their sofwares as default softwares in Samsung’s PC’s
NEW MEDIA KEY BLOCK released to HD disk manufacturers
+ new key blocks avalable in May
+ people can still use the keys to access the content form the disk printed before may 2007
SOFTWARE UPDATE
+ Updates may not been released  products on the market chich cannot play the disks thhat has new Media key block, released in this month
+ the process is an imperfect one and some users may not discover the problem until they put in a new HD disk and see the screen go blank.
"There's a whole eco-system of content owners, software companies, PC makers and consumer here,"

81. MPEG – 21 Standard
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82. Why MPEG-21
Today many elements exist to build an infrastructure for delivery and consumption of multimedia content. There is no ”big picture” to describe how these elements relate to each other. The aim of MPEG-21 is to describe how these various elements fit together.
The result is an open framework with both the content creator and content consumer as focal points.
The vision of MPEG-21 is to define a framework to enable transparent and augmented use of multimedia resources across a wide range of networks and devices used by different communities.
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83. MPEG-21 – The vision
A future where every human on the earth is potentially an element of a network involving billions of
content providers
value adders
packagers
service providers
consumers
resellers
To make this future real we need an infrastructure enabling electronic commerce of digital content
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84. MPEG-21 - Method of work
Define a framework supporting the vision statement
Involve relevant bodies in this effort
Identify the critical technologies of the framework
Understand how the components of the framework are related and identify where gaps exist
For each of the non-available technologies
If they fall under the MPEG expertise then develop them
Else engage other bodies to achieve their development
Perform the actual integration of the technologies
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85. Is MPEG trying to tame the hackers?
MPEG technologies have been used to innovate substantially the way people produce, offer, access and consume digital content
But MPEG has a also long history in working with the creative industries and rights holders’ communities on the identification, management and protection of intellectual property carried on systems designed to MPEG specifications.
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86. The basic elements of the MPEG-21 framework
What
A Digital Item is a structured digital object with a standard representation, identification and metadata within the MPEG-21 framework.
Who
A User is any entity that interacts in the MPEG-21 environment or makes use of a Digital Item.
User A
User B
Transaction / Use / Relationship
 Digital Item 
 Authorization / Value Exchange 
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87. Example of Digital Item “music compilation”
photos
video
animation graphics
lyrics
scores
MIDI files
interview with the singers
news related to the song
statement by an opinion maker
rating of an agency
position in the hit list
navigational information driven by user preferences
bargains
...
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88. What Users can do? Retail sale of content Consume content
Create content
Provide content
Archive content
Rate content
Enhance/deliver content
Aggregate content
Syndicate content
Retail sale of content
Consume content
Subscribe to content
Regulate content
Facilitate transactions that occur from any of the above
Regulate transactions that occur from any of the above
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89. MPEG-21 Multimedia Framework
Multimedia technology provides the different players in the multimedia value and delivery chain with excess of information and services.
No complete solutions exist that allow different communities (content, financial, communications, computer and electronics and their customers), each with their own models, rules, procedures, interests and content formats to interact efficientely using this infrastructure.
The multimedia content delivery chain encompasses content creation, production, delivery and consumption. To support this, the content has to be identified, described, managed and protected.
The aim of multimedia deliver system is to be interoperable, the transactions to be as simple as possible, and if is possible to be automated.
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90. The seven key elements defined in MPEG-21
Digital Item Declaration - a uniform and flexible abstraction and interoperable scheme for declaring Digital Items;
Digital Item Identification and Description - a framework for identification and description of any entity regardless of its nature, type or granularity;
Content Handling and Usage - provide interfaces and protocols that enable creation, manipulation, search, access, storage, delivery, and (re)use of content across the content distribution and consumption value chain;
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91. The seven key elements defined in MPEG-21
Intellectual Property Management and Protection - the means to enable content to be persistently and reliably managed and protected across a wide range of networks and devices;
Terminals and Networks - the ability to provide interoperable and transparent access to content across networks and terminals;
Content Representation - how the media resources are represented;
Event Reporting - the metrics and interfaces that enable Users to understand precisely the performance of all reportable events within the framework;
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92. The MultimediaFramework
Example:
”Container” ”Item” ”Resource”
Digital Item Declaration
Example:
Unique Identifiers
Content Descriptors
Example:
Storage Management
Content Personalisations
Digital Item Identification and Description
Content Management and Usage
User A
User B
Transaction / Use / Relationship
 Digital Item 
 Authorization / Value Exchange 
Event Reporting Metrics & Interfaces
Event Reporting Metrics & Interfaces
Intellectual Property Management and Protection
Example:
Encription
Authentification
Watermarking
Example:
Resource Abstraction
Resource Mgt. (QoS)
Terminals and Networks
Content Representation
Example:
Natural and Synthetic
Scalability
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93. MPEG-21 Part1: Vision, Technologies and Strategy
A Technical Report has been written to describe the multimedia framework and its architectural elements together with the functional requirements for their specification that was formally approved in September 2001.
The title “Vision, Technologies and Strategy” has been chosen to reflect the fundamental purpose of the Technical Report. This is to:
Define a 'vision' for a multimedia framework to enable transparent and augmented use of multimedia resources across a wide range of networks and devices to meet the needs of all users
Achieve the integration of components and standards to facilitate harmonisation of 'technologies' for the creation, management, transport, manipulation, distribution, and consumption of digital items.
Define a 'strategy' for achieving a multimedia framework by the development of specifications and standards based on well-defined functional requirements through collaboration with other bodies.
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94. Part 2: Digital Item Declaration
The purpose of the Digital Item Declaration (DID) specification is to describe a set of abstract terms and concepts to form a useful model for defining Digital Items.
This model specifically does not define a language in and of itself. Instead, the model helps to provide a common set of abstract concepts and terms that can be used to define such a scheme, or to perform mappings between existing schemes capable of Digital Item Declaration, for comparison purposes.
The DID technology is described in three normative sections:
Model: The Digital Item Declaration Model describes a set of abstract terms and concepts to form a useful model for defining Digital Items. Within this model, a Digital Item is the digital representation of “a work”, and as such, it is the thing that is acted upon (managed, described, exchanged, collected, etc.) within the model.
Representation: Normative description of the syntax and semantics of each of the Digital Item Declaration elements, as represented in XML. This section also contains some non-normative examples for illustrative purposes.
Schema: Normative XML schema comprising the entire grammar of the Digital Item Declaration representation in XML.
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95. The following sections describe the semantic “meaning” of the principle elements of the Digital Item Declaration Model:
Container
A container is a structure that allows items and/or containers to be grouped. These groupings of items and/or containers can be used to form logical packages (for transport or exchange) or logical shelves (for organization). Descriptors allow for the “labelling” of containers with information that is appropriate for the purpose of the grouping (e.g. delivery instructions for a package, or category information for a shelf).
It should be noted that a container itself is not an item; containers are groupings of items and/or containers.
Item
An item is a grouping of sub-items and/or components that are bound to relevant descriptors. Descriptors contain information about the item, as a representation of a work. Items may contain choices, which allow them to be customized or configured. Items may be conditional (on predicates asserted by selections defined in the choices). An item that contains no sub-items can be considered an entity -- a logically indivisible work. An item that does contain sub-items can be considered a compilation -- a work composed of potentially independent sub-parts. Items may also contain annotations to their sub-parts.
The relationship between items and Digital Items (as defined in ISO/IEC  :2001, MPEG-21 Vision, Technologies and Strategy) could be stated as follows: items are declarative representations of Digital Items.
Component
A component is the binding of a resource to all of its relevant descriptors. These descriptors are information related to all or part of the specific resource instance. Such descriptors will typically contain control or structural information about the resource (such as bit rate, character set, start points or encryption information) but not information describing the “content” within.
It should be noted that a component itself is not an item; components are building blocks of items.
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96. The following sections describe the semantic “meaning” of the principle elements of the Digital Item Declaration Model:
Anchor
An anchor binds descriptors to a fragment, which corresponds to a specific location or range within a resource.
Descriptor
A descriptor associates information with the enclosing element. This information may be a component (such as a thumbnail of an image, or a text component), or a textual statement.
Condition
A condition describes the enclosing element as being optional, and links it to the selection(s) that affect its inclusion. Multiple predicates within a condition are combined as a conjunction (an AND relationship). Any predicate can be negated within a condition. Multiple conditions associated with a given element are combined as a disjunction (an OR relationship) when determining whether to include the element.
Choice
A choice describes a set of related selections that can affect the configuration of an item. The selections within a choice are either exclusive (choose exactly one) or inclusive (choose any number, including all or none).
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97. The following sections describe the semantic “meaning” of the principle elements of the Digital Item Declaration Model:
Selection
A selection describes a specific decision that will affect one or more conditions somewhere within an item. If the selection is chosen, its predicate becomes true; if it is not chosen, its predicate becomes false; if it is left unresolved, its predicate is undecided.
Annotation
An annotation describes a set of information about another identified element of the model without altering or adding to that element. The information can take the form of assertions, descriptors, and anchors.
Assertion
An assertion defines a full or partially configured state of a choice by asserting true, false or undecided values for some number of predicates associated with the selections for that choice.
Resource
A resource is an individually identifiable asset such as a video or audio clip, an image, or a textual asset. A resource may also potentially be a physical object. All resources must be locatable via an unambiguous address.
Fragment
A fragment unambiguously designates a specific point or range within a resource. Fragment may be resource type specific.
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98. The following sections describe the semantic “meaning” of the principle elements of the Digital Item Declaration Model:
Statement
A statement is a literal textual value that contains information, but not an asset. Examples of likely statements include descriptive, control, revision tracking or identifying information.
Predicate
A predicate is an unambiguously identifiable Declaration that can be true, false or undecided.
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99. Example: Model of Digital Identification Declaration
The figure is an example showing the most important elements within this model, how they are related, and as such, the hierarchical structure of the Digital Item Declaration Model.
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100. Part 3 Digital Item Identification and Description
The scope of the Digital Item Identification and Description (DII&D) specification includes:
How to identify uniquely and describe Digital Items (and parts thereof) and other Entities.
The relationship between Digital Items (and parts thereof) and existing identification systems contains a list of relevant identification systems. This is not an exhaustive list and is subject to change over time.
The relationship between Digital Items (and parts thereof) and relevant description schemes contains a list of relevant description schemes. This is not an exhaustive list and is subject to change over time.
Digital Items and their parts within the MPEG-21 Framework are identified by encapsulating Uniform Resource Identifiers into the Identification DS. A Uniform Resource Identifier (URI) is a compact string of characters for identifying an abstract or physical resource, where a resource is defined as "anything that has identity".
The requirement that an MPEG-21 Digital Item Identifier be a URI is also consistent with the statement that the MPEG-21 identifier may be a Uniform Resource Locator (URL). The term URL refers to a specific subset of URI that is in use today as pointers to information on the Internet; it allows for long-term to short-term persistence depending on the business case.
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101. Relationship between Digital Item Declaration and Digital Item Identification & Description  
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102. Part 4: Intellectual Property Management and Protection (IPMP)
The 4th part of MPEG-21 defines an interoperable framework for Intellectual Property Management and Protection (IPMP).
The project includes standardized ways of retrieving IPMP tools from remote locations, exchanging messages between IPMP tools and between these tools and the terminal. It also addresses authentication of IPMP tools, and has provisions for integrating Rights Expressions according to the Rights Data Dictionary and the Rights Expression Language.
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103. Part 5: Rights Expression Language (REL)
Is seen as a machine-readable language that can declare rights and permissions using the terms as defined in the Rights Data Dictionary.
Is intended to provide flexible, interoperable mechanisms to support transparent and augmented use of digital resources in publishing, distributing, and consuming of electronic books, broadcasting, digital movies, digital music, interactive games, computer software and other creations in digital form, in a way that protects digital content and honours the rights, conditions, and fees specified for digital contents. It is also intended to support specification of access and use controls for digital content in cases where financial exchange is not part of the terms of use, and to support exchange of sensitive or private digital content.
Is intended to provide flexible interoperable mechanism to ensure personal data is processed in accordance with individual rights and to meet the requirement for Users to be able to express their rights and interests in a way that addresses issues of privacy and use of personal data.
A standard REL should be able to support guaranteed end-to-end interoperability, consistency and reliability between different systems and services. To do so, it must offer richness and extensibility in declaring rights, conditions and obligations, ease and persistence in identifying and associating these with digital contents, and flexibility in supporting multiple usage/business models.
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104. Part 6: Rights Data Dictionary (RDD)
RDD provides a set of clear, consistent, structured and integrated definitions of terms for use in the MPEG-21 Rights Expression Language.
Terms in RDD are categorized as Primitive, Native, Adopted and Mapped. The definitions of Primitive and Native terms are determined by the governance process of the RDD. Definitions of Adopted and Mapped terms are determined externally.
RDD is a semantic network through which the definitions of terms are developed through the medium of its primary data model (the Context Model) supported by two secondary models (the Resource Model and the Ascriptive Model).
RDD terms are drawn from a continually-expanding and diverse range of governed descriptive, legal and commercial metadata systems and schemes, supporting the description of rights and permissions in Digital Items, physical objects and abstract entities, incorporated within MPEG standards as well as those defined and governed elsewhere.
Terms will be added to the RDD or modified in accordance with its declared governance process.
RDD supports interoperability, so that metadata necessary for the management of rights and permissions can cross in and out of domains in an automated or partially-automated way with the minimum ambiguity or loss of semantic integrity.
Primitive, Native and Adopted terms within RDD do not define intellectual property rights or other legal entities. RDD Primitive, Native and Adopted terminology implies no assumptions about the nature or extent of specific legal rights, the commerce (or other) models through which rights may be exploited or protected, or the legal frameworks within which they operate.
RDD includes the terms from all metadata schemes and systems which have been mapped to it.
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105. Part 7: Digital Item Adaptation
The goal of the Terminals and Networks key element is to achieve interoperable transparent access to (distributed) advanced multimedia content by shielding users from network and terminal installation, management and implementation issues. This will enable the provision of network and terminal resources on demand to form user communities where multimedia content can be created and shared, always with the agreed / contracted quality, reliability and flexibility, allowing the multimedia applications to connect diverse sets of Users, such that the quality of the user experience will be guaranteed.
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106. MPEG-21 Summary Provides standardized and comprehensive
framework for dealing with digital content,
practically for any purpose
It is not used (yet?) because commercial interests until now promote closed proprietary solutions (example: mobile shops for content)
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