classification of optical discs compact disc physical medium data organization and encoding cd-rom...

1Input/Output Systems and Peripheral Devices (07-2)

7. Optical Discs

Classification of Optical DiscsCompact Disc Physical MediumData Organization and EncodingCD-ROM DriveCompact Disc TypesDVDBlu-ray Discs

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DVD

DVD OverviewDVD-ROMDVD-VideoDVD-AudioDVD-RDVD+RDVD-RAMDVD-RWDVD+RW

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Overview (1)

DVD – Digital Video Disc, Digital Versatile DiscDeveloped by the DVD Consortium changed into DVD Forum (www.dvdforum.org)Characteristics:

1, 2, 3, or 4 layersHigher capacity: 4.38 GB (1 layer), 15.9 GB (4 layers)Pit size is smaller Distance between tracks is lower Wavelength of the laser beam: 650 nm

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http://www.dvdforum.org/


Overview (2)

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CD DVD


Overview (3)

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Input/Output Systems and Peripheral Devices (07-2) 6

Overview (4)

Single-Sided and Double-Sided DVD Discs

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Overview (5)

The capacity of a double-sided disc is less than double the capacity of a single-sided disc:

The minimum pit length on both sides is increased from 0.4 µm to 0.44 µm The linear speed of the beam is 3.84 m/s on single-sided discs, compared to 3.49 m/s on double-sided discs

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DVD


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DVD-ROM (1)

Sector size: 2064 B (2048 – data)The sector is divided into 12 lines x 172 B

First line: contains the sector header (12 B)Sector identifier (ID) (4 B)Error correction code for the ID (2 B)Reserved area (6 B)

The next 160 B of the first line contain dataThe last line contains 4 B for error detection and correction of the data area

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DVD-ROM (2)

A number of 16 sectors make a blockSectors are placed dispersed on the disc10 bytes are added to the lines of each sector for the error correction code (ECC)A block contains 16 additional lines for the ECC This results in a block of 37,856 B

For recording both the CLV method and the CAV method are allowed

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DVD-ROM (3)

DVD discs can use the UDF (Universal Disk Format) file system

Defined by OSTA (Optical Storage Technology Association), www.osta.orgBased on ISO 13346/ECMA-167 standardIntended for DVD and CD-R/RW discs as replacement of the ISO 9660 systemOS independent UDF defines the data structures, character sets, read/write methods

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http://www.osta.org/


DVD


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DVD-Video (1)

Contains compressed video informationWide-screen video format

Movies have aspect ratios of 16:9 or 20:9 Options for transferring movies to video format for screens with 4:3 aspect ratio

Cropping the sides of the picture Shrinking the picture (“letterbox” format)

DVD discs allow to record movies with the aspect ratio of 16:9 high definition TV sets (HDTV)

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DVD-Video (2)

InteractivityIt is possible to play the movie from any place, pause playing, play in slow motion or fast forward Applications:

Multiple endings for a movie Interactive video games Recording from multiple camera angles

The disc is divided into titles (movies or albums) and parts of titles (chapters)

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DVD-Video (3)

Titles are composed of cells linked by one or more program chains sequential or random playback Individual cells can be used by several program chains

Multiple subtitles and languages 32 tracks for subtitles Up to 8 sound tracks for different languages (each with multiple channels)

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DVD-Video (4)

Higher quality video The digital video information is compressed through the MPEG-2 methodVideo systems that can be used:

PAL/SECAM: 625 lines, 25 frames/s (interlaced)NTSC: 525 lines, 29.97 frames/s (interlaced)

Pictures with 24 frames/s originated from movies, in progressive (non-interlaced) mode, are also typical

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DVD-Video (5)

Maximum resolution of pictures:720576 (PAL, 25 frames/s)720480 (NTSC, 29.97 frames/s)

For uncompressed video images, the bit rate is 124.416 Mbits/s Maximum bit rate for compressed video images: 9.8 Mbits/s; average rate: ~3.5 Mbits/s (a reduction of 36:1) Number of lines for the TV sets: 540 (standard TV), 405 (16:9 wide-screen TV)

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DVD-Video (6)

Higher quality audio Each of the 8 audio tracks can have one of the following three formats:

LPCM (Linear PCM): 1 up to 8 channelsDolby Digital (AC-3): 1 up to 5.1 channels MPEG-2 audio: 1 up to 5.1 or 7.1 channels

Other two optional formats are provided (require external decoders):

DTS (Digital Theater System)SDDS (Sony Dynamic Digital Sound)

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DVD-Video (7)

Dolby DigitalMulti-channel digital audio format Uses a lossy coding technology (AC-3) of the original PCM audio data Sampling rate: 48 KHz, up to 24 bits per sample Bit rate: 64 .. 448 Kbits/s (384 Kbits/s for 5.1 channels)Format used for the audio tracks of most DVD discs

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DVD-Video (8)

MPEG audioMulti-channel digital audio format Uses a lossy compression of the original PCM audio data The MPEG-1 and MPEG-2 formats are supportedSampling rate: 48 KHz, 16 bits per sample Bit rate: 32 .. 912 Kbits/s (384 Kbits/s is the normal average rate)The MPEG-2 Layer-3 (MP3) and MPEG-2 AAC (Advanced Audio Coding) formats are not supported

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DVD


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DVD-Audio (1)

Intended for high-fidelity audio recordings Advantages compared to the CD-DA disc:

Higher audio qualityAdditional channels for spatial sound

Sampling rates:44.1 KHz and multiples (88.2; 176.4 KHz)48 KHz and multiples (96; 192 KHz)

Number of bits per sample: 16; 20; 2401/15/2015


DVD-Audio (2)

Number of channels: 1 .. 6The most used formats: stereo, 5.1

Maximum dynamic range (192 KHz, 24 bits): 144 dBMaximum data rate: 9.6 Mbps

At highest quality: 2 channels, ~67 min.Compression can be used

Lossless: MLP (Meridian Lossless Packing) → ~135 min. for: 5.1 channels, 96 KHz, 24 bits per sample

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DVD-Audio (3)

Compatibility with stereo players: by a technique of converting (downmixing) the 5.1-channel format to the stereo format DVD-Audio discs may also contain: navigation menus; text subtitles; still images; a DVD-Video area There are discs formatted as DVD-Audio on one side and DVD-Video on the other side Copy protection: CPPM (Content Protection for Prerecorded Media), developed by 4C Entity

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DVD


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DVD-R (1)

Developed by Pioneer The format is approved by the DVD ForumUses a technology similar to that of the CD-R discs

The organic dyes are different Two variants: DVD-R(A) and DVD-R(G)DVD-R(A) (Authoring)

Intended for professional applications: archiving, disc production Laser wavelength: 635 nm

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DVD-R (2)

DVD-R(G) (General purpose)Intended for consumer applications Laser wavelength: 650 nmThe cost of drives and media is lower compared to that of DVD-R(A)Includes a copy protection system

DVD-R(G) drives cannot copy DVD discs that use an encryption system

Capacity: 4.38 GB (single layer – SL); 7.95 GB (double layer – DL)

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DVD


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DVD+R (1)Developed by DVD+RW Alliance (www.dvdrw.com) The format is not approved by the DVD ForumDiscs can be recorded only once Capacity: 4.37 GB (SL); 7.92 GB (DL)DVD+R drives are not compatible with DVD-R drives

Usually, the drives are hybrid: DVDR01/15/2015

http://www.dvdrw.com/


DVD+R (2)The disc is engraved with a spiral groove that has a sinusoidal deviation

Frequency of the sinusoid: 817 KHz (at 1x)Allows a correct positioning of the spot and control of the rotational speedContains addressing information for blocks ADIP (ADdress In Pre-groove)Addressing information is stored by phase modulation of the sinusoid

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DVD+R (3)

Improvements of the DVD-R technologyThe spot tracking control system and ADIP addressing is less susceptible to interference and errors

Higher reliability at higher speeds The error management system is more robust

More accurate writing independent of the quality of the media

More accurate linking of multiple sessions 01/15/2015


DVD


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DVD-RAM (1)Developed by the DVD Forum Uses the phase-change technology, like the CD-RW discsData are stored on concentric tracks A spiral groove is used for synchronizing data writing with the spin of the disc

The groove is pressed at manufacturing There are data marks written inside and outside the groove

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DVD-RAM (2)

First-generation discs had a capacity of 2.40 GBLater, the capacity was extended to 4.38 GB

Reducing the mark size (from 0.43 µm to 0.30 µm)Reducing the track pitch (from 0.74 µm to 0.59 µm)

Hardware sectoring is used Sector headers are engraved on the disc during manufacturing

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Input/Output Systems and Peripheral Devices (07-2) 35

DVD-RAM (3)

Hardware sectoring of DVD-RAM discs

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DVD-RAM (4)

Early discs were only available encased in a cartridge Today’s drives allow to use the discs with or without the cartridge The disc type is indicated by a digit

Type 1: 120 mm, cartridge, non-removableType 2: 120 mm, cartridge, removable, one side Type 5: 120 mm, no cartridge, two sidesType 9: 80 mm, no cartridge, one side

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DVD-RAM (5)

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DVD-RAM (6)

Advantages of DVD-RAM discs Long lifetime (minimum 30 years)Number of rewrites: over 100,000

At higher speeds, the number of rewrites is lower (at 5x speed 10,000)

Reliable writing: verification by the driveDisc defect management system A burning software is not required

The disc can be accessed like a removable hard disk

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DVD-RAM (7)

Fast access to small files on the disc In video recorders, discs can be written to and read at the same time

Disadvantages of DVD-RAM discs Less compatibility compared to other rewriteable discs Higher cost of the discs Slower writing speed

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DVD


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DVD-RW (1)

Developed by Pioneer The format is approved by the DVD ForumOriginates from the DVD-R(A) format For the physical medium the phase-change technology is used

The reflectivity is lower (18..30% compared to 45..80% for DVD-ROM)Early DVD drives confused the DVD-RW discs with two-layer DVD-ROM discs

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DVD-RW (2)

Blank discs contain:Address information between the groovesA lead-in track copy protection

Advantages:The ability for erasing and rewriting If there are writing errors, the disc can be used by erasing the faulty data DVD-RW discs can be read by most of today’s DVD drives

Number of rewrites: ~100001/15/2015


DVD


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DVD+RW (1)Developed by the DVD+RW AllianceThe format is not approved by the DVD ForumDesigned as a random-access medium The intention was to ensure compatibility with regular DVD drives

However, DVD+RW drives are not compatible with DVD-RW drives Usually, the drives are hybrid: DVDRW

The same phase-change technology is used as with CD-RW and DVD-RW discs

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DVD+RW (2)

For recording, the CAV method can also be used (besides the CLV method)

Increased performance for random accessThe power consumption decreases

The same type of spiral groove is used as with DVD+R discs

Encodes the addresses of 32 KB blocks Each 2 KB cluster can be accurately located clusters can be rewritten independently

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DVD+RW (3)

The high-frequency sinusoidal deviation of the groove allows for lossless linking

With other rewriteable discs, part of the blocks are allocated as link blocks start and end of writing For DVD+RW discs, link blocks are not needed It is possible to resume writing after an area written before with a precision of 1 µm

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DVD+RW (4)

DVD+RW discs require formatting before use

DVD+RW drives format the discs automatically If the formatting is interrupted, the drive will resume formatting the next time the disc is inserted

An automatic defect management system is used

Defective areas are masked 01/15/2015


7. Optical Discs

Classification of Optical DiscsCompact Disc Physical MediumData Organization and EncodingCD-ROM DriveCompact Disc TypesDVDBlu-ray Discs

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Blu-ray Discs

Blu-ray DiscsOverviewBD-R/RE AV FormatBD-ROM AV FormatHigh-Capacity Blu-ray Discs

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Overview (1)

BD – Blu-ray DiscDeveloped by the Blu-ray Disc Association (Sony, Pioneer, Dell, Apple)Diameter of 12 cm or 8 cmUse a laser with a wavelength of 405 nm (blue-violet)Higher capacity compared to DVD discs:

Single-layer (SL): 23.28 GB (25 GB in decimal)Dual-layer (DL): 46.56 GB (50 GB in decimal)

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Overview (2)

Focusing is more precise Depends on the diffraction and wavelengthThe recording layer is closer to the surface of the disc The wavelength is shorter

The pit size is smallerMinimum length: 0.15 µm (0.4 µm for DVD)

The track pitch is reduced 0.32 µm (0.74 µm for DVD)

Data encoding is more efficient 01/15/2015


Overview (3)

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Overview (4)

Early discs required a protective cartridge Today’s discs are covered with a protective hard coating layer the cartridge is not needed

Silicon dioxide resinTransparent and thin layer (2 .. 5 µm)Protects against damage from accidental impactRepels dust and fingerprints conductive material

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Overview (5)

Discs typesBD ROMBD-R (BD-Recordable)BD-RE (BD-Rewritable)Each type also has an AV (Audio Visual) format

Write and read speedsTransfer rate at 1x speed: 4.29 MB/sHigher speeds: 2x, 4x, …, 12x

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Overview (6)

BD SpeedTransfer Rate

(MB/s)Equivalent DVD

SpeedEquivalent CD

Speed

1x 4.29 3.3x 29.4x

1.5x 6.43 4.9x 44.1x

2x 8.57 6.5x 58.8x

4x 17.15 13.0x 117.5x

6x 25.72 19.5x 176.3x

8x 34.30 26.0x 235.1x

10x 42.87 32.5x 293.8x

12x 51.45 39.0x 352.6x

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Overview (7)

Disc rotational methodsConstant Linear Velocity (CLV): approx. 4.9 m/s at a speed of 1x Constant Angular Velocity (CAV): the rotational speed is constantZoned Constant Linear Velocity (ZCLV): the disc is divided into zones; progressively faster CLV speeds are used in each zonePartial Constant Angular Velocity (PCAV): CAV (near the center) + CLV

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Blu-ray Discs


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BD-R/RE AV Format (1)

Designed to record and play back digital TV broadcasts on BD-R and BD-RE discs

Approx. 2 hours of HD material or 12 hours of SD material on a SL disc

For video and audio multiplexing, the MPEG-2 Transport Stream format is used

Packets of 188 B Multiple channels (TV, audio) and electronic program guide (EPG) information are multiplexed

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BD-R/RE AV Format (2)

BD-R/RE AV discs also accept data from an HD video camcorder

Streams in MPEG-2 formatTwo layers of organizational structure for managing AV data

Clip layer: contains the partial transport streams and clip information filesPlaylist layer: allows the user to view, edit, and group clips through playlist files

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Blu-ray Discs


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BD-ROM AV Format (1)

Designed for distributing HD moviesHigh Definition Movie (HDMV) mode

Extended DVD-Video features: support for HD video; more sophisticated navigation and visual possibilities

BD Java (BD-J) modeApplication development environmentEnables interactivity and optional Internet and network connection

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Uses the same MPEG-2 Transport Stream format

The transport stream is formed by encoding and multiplexing each component

BD-ROM AV discs (HDMV, BD-J) with 2D video content: are played back at 1.5x CLV speed (6.4 MB/s)BD-ROM AV discs with 3D video content: are played back at 2x CLV speed (8.5 MB/s)

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HDMV ModeThe multiplexed stream can be extended with individual streams stored separately are decoded at the same timeFeatures: subtitles, menus, button soundsPlayback image: formed by overlaying five independent image planesBD-J background planeTwo video planes (primary, secondary): enable picture-in-picture (PiP) playback

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Presentation graphics plane: for subtitlesInteractive graphics plane: for graphic menus (information, buttons for navigation) Up to nine video streamsResolutions from 720 × 480 (SD, 60i) to 1920 × 1080 (HD, 60i)Video encoding methods:

MPEG-2MPEG-4 AVC/H.264VC-1 (Microsoft Windows Media)

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Up to 32 audio streams with up to 8 channels each (24 bits, 192 KHz) Mandatory audio encoding methods:

LPCM (Linear PCM)Dolby Digital (AC-3)DTS (Digital Theater System)

Optional audio encoding methods:Dolby Digital Plus Lossless encoding: Dolby TrueHD, DTS-HD Master Audio

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BD-J ModeExtends the HDMV mode’s features Frame accurate animationInteractive audio Internet and network connectionControl of local storage devicesContent extension: games, access to online material, extra languages or commentariesCompliant with Java 2 Micro Edition (J2ME)

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Blu-ray Discs


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High-Capacity Blu-ray Discs (1)

High Capacity BD specifications (2010)BD-R XL discs

Triple-layer (TL) discs: 33.33 GB per layer, capacity of 100 GBQuadruple-layer (QL) discs: 32 GB per layer, capacity of 128 GB

BD-RE XL discsTriple-layer (TL) discs: 33.33 GB per layer, capacity of 100 GB

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High-Capacity Blu-ray Discs (2)

Experimental discs with higher capacitiesSony: BD-ROM discs of 200 GB (8 layers)Pioneer: BD-ROM discs of 400 GB (16 layers) and 500 GB (20 layers)TDK: prototypes of BD-R discs using inorganic materials for the recording layers

200 GB (6 layers)400 GB (16 layers)512 GB (16 layers)

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Summary (1)

DVDs have higher capacities compared to CDsReducing the pit size, distance between tracks, and wavelength of the laserUsing double-sided discs with one or two layers on each side

Data on DVD-ROM discs are organized into blocks, sectors, and linesDVD-Video discs provide wide-screen video formats, interactivity, multiple subtitles and languages, higher-quality video and audio

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Summary (2)

DVD-R and DVD+R discs use a recording technology similar to that of CD-R discs

DVD+R discs ensure higher reliability, more accurate writing and linking of multiple sessions

DVD-RAM discs allow an increased number of rewrites compared to DVD-RW discsDVD-RW and DVD+RW discs use the same phase-change technology as CD-RW discs

DVD+RW discs allow for lossless linking between successive writing operations

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Summary (3)

Blu-ray discs have higher capacities compared to DVDsThe BD-R/RE AV format enables to record and play back TV broadcasts The BD-ROM AV format is used for distributing commercial HD movies

HDMV mode: provides extended DVD-Video features at HD resolutionsBD-J mode: extends the HDMV mode with interactivity and Internet connection

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Concepts, Knowledge (1)

Characteristics of DVDsDVD-ROM organization: lines, sectors, blocksDVD-Video organization: titles, chapters, cells, program chainsDVD-Audio discsDVD-R disc variants: DVD-R(A), DVD-R(G)Spiral groove of DVD+R discsImprovements introduced by DVD+R discs

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Concepts, Knowledge (2)

Advantages and disadvantages of DVD-RAM discsSpiral groove of DVD+RW discsCharacteristics of Blu-ray discsBD-R/RE AV formatHDMV mode of BD-ROM AV formatBD-J mode of BD-ROM AV formatBD-R/RE XL discs

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classification of optical discs compact disc physical medium data organization and encoding cd-rom...

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