Transcript Overview of Digital Video Standards

Overview of Digital
Video Standards
Naohiro Shichijo
Interfaculty Initiative in Information Studies
The University of Tokyo
<[email protected]>
Digital Video Standards
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Focuses on professional digital video standards
(ie. non-consumer)
Describe following items briefly:
Video Signal
 Sampling
 Encoding
 Transferring
 Tape recording
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Roadmap
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Analog Video
Digital Video
HDTV
Digital Video Recording
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Digital Video at Work -1
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Contents creation in
analog/digital television.
Cinema production
Computer graphics
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Digital Video at Work -2
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DTV
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DVB
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Advanced Television System (USA, Taiwan)
http://www.atsc.org/
Digital Video Broadcasting (Europe)
http://www.dvb.org/
ISDB
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Integrated Services Digital Broadcating (Japan)
http://www.arib.or.jp/
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History of Digital Video -0
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Around 1970: Digital Black-box Systems
Frame synchronizer
 Standards converter
 Timebase corrector
 Analog I/O
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Around 1980: Digital VTR Systems
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DVE, Graphic system, Still store
 very limited interoperability
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History of Digital Video Standards
(1/2)
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1982: ITU-R Rec. BT. 601
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1986: ITU-R Rec. BT. 657
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19mm Type D-2 Composite Format (includes NTSC, PAL)
1993: SMPTE 264M,265M
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Composite Digital Encoding for NTSC(known as D-2)
1993: IEC61179
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Digital television tape recording. Standards for the international exchange of
television programs on magnetic tape
 SMPTE 224M~228M (known as D-1)
1990: SMPTE 224M~248M
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Encoding parameters for digital television for studios (describes 4:2:2 encoding)
½ -in Type D-3 Composite Format 525/60, 625/50
1996: SMPTE 279M
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½ -in Type D-5 Component Format – 525/60 and 625/50
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History of Digital Video Standards
(2/2)
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1995: SMPTE 227M,228M
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1998: SMPTE 306M,307M,314M
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Television Digital Recording 19mm – Type D-6
Television Digital Recording 6.35mm – Type D-7
Component Format 25Mbit/s, 50Mbit/s (also known as
DVCPRO)
1999: SMPTE 316M,317M
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Television Digital Recoding 12.65mm – Type D-9 (also
known as Digital-S)
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Introduction to Analog Video
TV Standards
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NTSC
PAL
SECAM
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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
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Tristimulus chromaticity
coordinate system, (X, Y,
Z)
x=X/(X+Y+Z),
y=Y/(X+Y+Z)
Color is represented in
the CIE2002 primarily
colors.
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Basic ingredients
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Brightness information
EY  0.587EG  0.114EB  0.299ER
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Chrominance information
ER  EY  0.587EG  0.114EB  0.701ER
EB  EY  0.587EG  0.886EB  0.299ER
EB Y  0.492EB  EY 
ER Y  0.877ER  EY 
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(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
Signal Sampling
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Continuous analog signal is sampled in equally T
interval.
1
fS 
(sampling frequency)
T
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Nyquist’s theorem:
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Sampling frequency should be larger than twice of sampled
signal frequency
Sampling frequency:
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4fsc … 14.3MHz (NTSC), 17.7MHz (PAL)
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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
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Composite Digital Video
Component Digital Video
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Composite Digital Signal
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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
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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
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CCIR601 standard. (ITU-R. 601)
Several standard sampling rates:
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4:2:2 sampling
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4:1:1 sampling
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Luma at 13.5MHz, Chroma at 6.75MHz (interleaved)
4:4:4 sampling
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Luma at 13.5MHz (4x3.375MHz), Chroma at 3.375MHz
4:2:0 sampling
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Luma at 13.5MHz, Chroma at 6.75MHz (2x3.375MHz)
Luma and chroma are sampled at 13.5MHz
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Sampling structure (4:2:2)
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Horizontal Sync Relationship
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Multiplexing luma and chroma
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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
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In component digital, analog sync signals are not
sampled.
1440~1443 words: EAV (End of active video)
1712~1715 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, P0~P3: 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
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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.”
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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
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Uses one coax cable.
Multiplexes multi-channel audio and Video.
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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
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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)
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Channel coding
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NRZI (to reduce DC component compared to NRZ)
Uses scrambler to further reduce DC component.
G1(X) = X9 + X4 + 1. G2(X) = X + 1
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Synchronizing
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TRS-ID (Timing reference signal and line number identification)
TRS: 4 words (3FF 000 000 000) are inserted at 790~793th 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)
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Compatible with SDI
Header in HANC
User Data in Digital Active Video region (SAV~EAV)
Can contain both fixed and variable length data packets
in User Data region
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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
HDTV formats
SMPTE 274M
SMPTE 293M
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Basic difference with SDTV
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Primary Colors
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Luma and Chroma equations
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Raster Structure
Progressive Systems  straightforward
 Interlace Systems  rather compilicated
that is:
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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
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HD-SDI:
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Almost same as SD versions.
Same channel encoding
 Bit rate is 1.486Gb/sec
 Uses coax cable or optical fiber
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HD-SDTI:
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For compressed formats
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HD-SDI C/Y payloads
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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
Digital video tape recorders
(DVTRs)
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SMPTE standardizes TV studio level DVTRs.
D-1, D-2, D-3, D-5, HD-D5, D-6, D-7, D-9, D10, D-11, D-12
Digital Betacam, Betacam SX are not SMPTE
standard, but commonly used.
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Uncompressed DVTRs
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D-1, D-5: component digital
D-2, D-3: composite digital
D-6: component digital HDTV
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Compressed DVTRs
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D-7 (DVCPRO): 25Mb/s, 50Mb/s
In 25Mb/s, 4:1:1, In 50Mb/s, 4:2:2
 Compressed 1/3.3~1/5 by SMPTE314M (DV)
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D-9 (Digital S)
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50Mb/s, 4:2:2 sampled, 1/3.3 compressed by DCT
Betacam SX
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4:2:2 sampled, 1/10 compressed by MPEG-2
(MP@ML)
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Compressed HDTV DVTRs
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HD-D5
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Compressed 1/4.3 by DCT
HDCAM
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Related information
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SMPTE (professional video standards)
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ITU (e.g. CCIR-601)
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http://www.iec.ch/
ATSC (ATV in US)
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http://www.itu.int/
IEC (mainly for consumer standards)
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http://www.smpte.org/
http://www.atsc.org/
DVB (digital broadcast in Europe)
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http://www.dvb.org/
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