Overview of Digital Video Standards

1
Overview of Digital Video Standards

• Naohiro Shichijo
• Interfaculty Initiative in Information Studies
• The University of Tokyo
• ltshichi_at_iii.u-tokyo.ac.jpgt

2
Digital Video Standards

• Focuses on professional digital video standards
  (ie. non-consumer)
• Describe following items briefly
• Video Signal
• Sampling
• Encoding
• Transferring
• Tape recording

3
Roadmap

• Analog Video
• Digital Video
• HDTV
• Digital Video Recording

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Digital Video at Work -1

• Contents creation in analog/digital television.
• Cinema production
• Computer graphics

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Digital Video at Work -2

• DTV
• Advanced Television System (USA, Taiwan)
• http//www.atsc.org/
• DVB
• Digital Video Broadcasting (Europe)
• http//www.dvb.org/
• ISDB
• Integrated Services Digital Broadcating (Japan)
• http//www.arib.or.jp/

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History of Digital Video -0

• Around 1970 Digital Black-box Systems
• Frame synchronizer
• Standards converter
• Timebase corrector
• ? Analog I/O
• Around 1980 Digital VTR Systems
• DVE, Graphic system, Still store
• ? very limited interoperability

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History of Digital Video Standards (1/2)

• 1982 ITU-R Rec. BT. 601
• Encoding parameters for digital television for
  studios (describes 422 encoding)
• 1986 ITU-R Rec. BT. 657
• Digital television tape recording. Standards for
  the international exchange of television programs
  on magnetic tape? SMPTE 224M228M (known as D-1)
• 1990 SMPTE 224M248M
• Composite Digital Encoding for NTSC(known as D-2)
• 1993 IEC61179
• 19mm Type D-2 Composite Format (includes NTSC,
  PAL)
• 1993 SMPTE 264M,265M
• ½ -in Type D-3 Composite Format 525/60, 625/50
• 1996 SMPTE 279M
• ½ -in Type D-5 Component Format 525/60 and
  625/50

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History of Digital Video Standards (2/2)

• 1995 SMPTE 227M,228M
• Television Digital Recording 19mm Type D-6
• 1998 SMPTE 306M,307M,314M
• Television Digital Recording 6.35mm Type D-7
  Component Format 25Mbit/s, 50Mbit/s (also known
  as DVCPRO)
• 1999 SMPTE 316M,317M
• Television Digital Recoding 12.65mm Type D-9
  (also known as Digital-S)

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Introduction to Analog Video
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TV Standards

• NTSC
• PAL
• SECAM

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(No Transcript)
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Standard Definition of Composite Video Parameters
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Colorimetry
SMPTE CIE x-y color chart By cietoppm.c
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Luminance and Chromaticity

• Tristimulus chromaticity coordinate system, (X,
  Y, Z)
• xX/(XYZ), yY/(XYZ)
• Color is represented in the CIE2002 primarily
  colors.

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Basic ingredients

• Brightness information
• Chrominance information

(scaled to prevent overloading)
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Composite Video Encoder
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NTSC Equation (170M)
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NTSC composite signal spectrum
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Compositing waveforms
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Horizontal Blanking Interval
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Field Structure
Even field
Complete Frame
Odd field
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Horizontal Blank Structure
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Introduction to Digital Video
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Signal Sampling

• Continuous analog signal is sampled in equally T
  interval.
• Nyquists theorem
• Sampling frequency should be larger than twice of
  sampled signal frequency
• Sampling frequency
• 4fsc 14.3MHz (NTSC), 17.7MHz (PAL)

(sampling frequency)
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Aliasing
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Sampled spectrum
Ideal spectrum
Spectrum of filtered signal
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Quantization
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Digital Video Signals

• Composite Digital Video
• Component Digital Video

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Composite Digital Signal

• 4fsc NTSC, PAL composite digital
• Sampled at 4 times of sub carrier frequency ( fsc
  )
• 8bits / 10bits per sample
• Used in D-2, D-3 etc.

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I-Q representation
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Sampling timings
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Quantization

• 10bits/sample
• 8 bits/sample (two LSBs are set zero, shifted
  twice)

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Quantization in 244M
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Raster structures
(NTSC)
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Component Digital Signal

• CCIR601 standard. (ITU-R. 601)
• Several standard sampling rates
• 422 sampling
• Luma at 13.5MHz, Chroma at 6.75MHz (2x3.375MHz)
• 411 sampling
• Luma at 13.5MHz (4x3.375MHz), Chroma at 3.375MHz
• 420 sampling
• Luma at 13.5MHz, Chroma at 6.75MHz (interleaved)
• 444 sampling
• Luma and chroma are sampled at 13.5MHz

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Sampling structure (422)
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Horizontal Sync Relationship
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Multiplexing luma and chroma

• Total sample number is 1716 words (NTSC), 1728
  words (PAL) per line.
• In digital active lines, 720 samples for Y, 360
  samples for Cb and Cr ? 1440 samples in total.
• Digital blanking is 276 words (NTSC), 288 words
  (PAL)
• Samples are transferred in Cb, Y, Cr sequence

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Timing reference signals

• In component digital, analog sync signals are not
  sampled.
• 14401443 words EAV (End of active video)
• 17121715 words SAV (Start of active video)
• SAV and EAV is represented as 3FF 000 000 XYZ
• XYZ (MSB)0,H,V,F,P0,P1,P2,P3,0,0(LSB)2
• F field ID, V vertical blanking information, H
  horizontal blanking information, P0P3 error
  correction bits.

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Multiplex Structure
ITU-R BT.656-4
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Ancillary data spaces
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Ancillary data

• Data between EAV and SAV, and VLI are defined as
  ancillary data. Those are
• Horizontal ancillary area HANC
• Vertical ancillary area VANC
• They start with sequence of 000 3FF 3FF.
• HANC 140,700 words/frame 42.2Mb/s
• VANC 56,160 words/frame 13.5Mb/s
• In total 55.7Mb/s (in NTSC)

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Serial digital transmission

• Uses one coax cable.
• Multiplexes multi-channel audio and Video.
• Audio channels are inserted in ancillary areas.
• AES/EBU 2ch-digital audio 3.072Mb/s
• In 4fsc NTSC format, 4 channels (or two
  2-channels) can be multiplexed.
• SMPTE 259M-1997
• Level A -- 143 Mb/s, NTSC
• Level B -- 177 Mb/s, PAL
• Level C -- 270 Mb/s, 525/625 component
• Level D -- 360 Mb/s, 525/625 component

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Serial Digital Interface (SDI)

• Channel coding
• NRZI (to reduce DC component compared to NRZ)
• Uses scrambler to further reduce DC component.
• G1(X) X9 X4 1. G2(X) X 1
• Synchronizing
• TRS-ID (Timing reference signal and line number
  identification)
• TRS 4 words (3FF 000 000 000) are inserted at
  790793th words in NTSC
• ID 1word inserted at 794th word. Composed with
  line number and field number

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Serial Data Transport Interface (SDTI)

• Compatible with SDI
• Header in HANC
• User Data in Digital Active Video region
  (SAVEAV)
• Can contain both fixed and variable length data
  packets in User Data region
• Usually, data packets will carry compressed video
  data
• E.g. MPEG2 (in D-10), DV (in D-7) etc...

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SDTI Payload
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HDTV
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HDTV formats
SMPTE 274M
SMPTE 293M
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Basic difference with SDTV

• Primary Colors
• Luma and Chroma equations

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Raster Structure

• Progressive Systems ? straightforward
• Interlace Systems ? rather compilicated
• that is
• Since active line is 1125, one frame is
  decomposed to 563 and 562 line fields.

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Raster Structure of 1125P/I Systems
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HDTV Vertical Blanking Structure
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HD-SDI and HD-SDTI

• HD-SDI
• Almost same as SD versions.
• Same channel encoding
• Bit rate is 1.486Gb/sec
• Uses coax cable or optical fiber
• HD-SDTI
• For compressed formats

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HD-SDI C/Y payloads

• Each C/Y multiplexed line is treated as two
  lines.
• Original multiplexed line contains two headers. C
  then Y
• Double rate operation doubles line numbers for
  progressive mode.

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Interleaved Data Stream in HD-SDI
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SDTI Header and User Data Formats
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Digital Video Recording
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Digital video tape recorders (DVTRs)

• SMPTE standardizes TV studio level DVTRs.
• D-1, D-2, D-3, D-5, HD-D5, D-6, D-7, D-9, D-10,
  D-11, D-12
• Digital Betacam, Betacam SX are not SMPTE
  standard, but commonly used.

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Uncompressed DVTRs

• D-1, D-5 component digital
• D-2, D-3 composite digital
• D-6 component digital HDTV

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Compressed DVTRs

• D-7 (DVCPRO) 25Mb/s, 50Mb/s
• In 25Mb/s, 411, In 50Mb/s, 422
• Compressed 1/3.31/5 by SMPTE314M (DV)
• D-9 (Digital S)
• 50Mb/s, 422 sampled, 1/3.3 compressed by DCT
• Betacam SX
• 422 sampled, 1/10 compressed by MPEG-2 (MP_at_ML)

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Compressed HDTV DVTRs

• HD-D5
• Compressed 1/4.3 by DCT
• HDCAM

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Related information

• SMPTE (professional video standards)
• http//www.smpte.org/
• ITU (e.g. CCIR-601)
• http//www.itu.int/
• IEC (mainly for consumer standards)
• http//www.iec.ch/
• ATSC (ATV in US)
• http//www.atsc.org/
• DVB (digital broadcast in Europe)
• http//www.dvb.org/