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Overview of Digital Video Standards. Naohiro Shichijo Interfaculty Initiative in Information Studies The University of Tokyo <shichi@iii.u-tokyo.ac.jp>. Digital Video Standards. Focuses on professional digital video standards (ie. non-consumer) Describe following items briefly:
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Overview of Digital Video Standards Naohiro Shichijo Interfaculty Initiative in Information Studies The University of Tokyo <shichi@iii.u-tokyo.ac.jp>
Digital Video Standards • Focuses on professional digital video standards (ie. non-consumer) • Describe following items briefly: • Video Signal • Sampling • Encoding • Transferring • Tape recording Naohiro Shichijo, The University of Tokyo
Roadmap • Analog Video • Digital Video • HDTV • Digital Video Recording Naohiro Shichijo, The University of Tokyo
Digital Video at Work -1 • Contents creation in analog/digital television. • Cinema production • Computer graphics Naohiro Shichijo, The University of Tokyo
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/ Naohiro Shichijo, The University of Tokyo
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 Naohiro Shichijo, The University of Tokyo
History of Digital Video Standards (1/2) • 1982: ITU-R Rec. BT. 601 • Encoding parameters for digital television for studios (describes 4:2:2 encoding) • 1986: ITU-R Rec. BT. 657 • 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 • 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 Naohiro Shichijo, The University of Tokyo
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) Naohiro Shichijo, The University of Tokyo
TV Standards • NTSC • PAL • SECAM Naohiro Shichijo, The University of Tokyo
Standard Definition of Composite Video Parameters Naohiro Shichijo, The University of Tokyo
Colorimetry SMPTE CIE x-y color chart By cietoppm.c Naohiro Shichijo, The University of Tokyo
Luminance and Chromaticity • 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. Naohiro Shichijo, The University of Tokyo
Basic ingredients • Brightness information • Chrominance information (scaled to prevent overloading) Naohiro Shichijo, The University of Tokyo
Composite Video Encoder Naohiro Shichijo, The University of Tokyo
NTSC Equation (170M) Naohiro Shichijo, The University of Tokyo
NTSC composite signal spectrum Naohiro Shichijo, The University of Tokyo
Compositing waveforms Naohiro Shichijo, The University of Tokyo
Horizontal Blanking Interval Naohiro Shichijo, The University of Tokyo
Field Structure Even field Complete Frame Odd field Naohiro Shichijo, The University of Tokyo
Horizontal Blank Structure Naohiro Shichijo, The University of Tokyo
Signal Sampling • Continuous analog signal is sampled in equally T interval. • Nyquist’s theorem: • Sampling frequency should be larger than twice of sampled signal frequency • Sampling frequency: • 4fsc … 14.3MHz (NTSC), 17.7MHz (PAL) (sampling frequency) Naohiro Shichijo, The University of Tokyo
Aliasing Naohiro Shichijo, The University of Tokyo
Sampled spectrum Ideal spectrum Spectrum of filtered signal Naohiro Shichijo, The University of Tokyo
Quantization Naohiro Shichijo, The University of Tokyo
Digital Video Signals • Composite Digital Video • Component Digital Video Naohiro Shichijo, The University of Tokyo
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. Naohiro Shichijo, The University of Tokyo
I-Q representation Naohiro Shichijo, The University of Tokyo
Sampling timings Naohiro Shichijo, The University of Tokyo
Quantization • 10bits/sample • 8 bits/sample (two LSBs are set zero, shifted twice) Naohiro Shichijo, The University of Tokyo
Quantization in 244M Naohiro Shichijo, The University of Tokyo
Raster structures (NTSC) Naohiro Shichijo, The University of Tokyo
Component Digital Signal • CCIR601 standard. (ITU-R. 601) • Several standard sampling rates: • 4:2:2 sampling • Luma at 13.5MHz, Chroma at 6.75MHz (2x3.375MHz) • 4:1:1 sampling • Luma at 13.5MHz (4x3.375MHz), Chroma at 3.375MHz • 4:2:0 sampling • Luma at 13.5MHz, Chroma at 6.75MHz (interleaved) • 4:4:4 sampling • Luma and chroma are sampled at 13.5MHz Naohiro Shichijo, The University of Tokyo
Sampling structure (4:2:2) Naohiro Shichijo, The University of Tokyo
Horizontal Sync Relationship Naohiro Shichijo, The University of Tokyo
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 Naohiro Shichijo, The University of Tokyo
Timing reference signals • 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. Naohiro Shichijo, The University of Tokyo
Multiplex Structure ITU-R BT.656-4 Naohiro Shichijo, The University of Tokyo
Ancillary data spaces Naohiro Shichijo, The University of Tokyo
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) Naohiro Shichijo, The University of Tokyo
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 Naohiro Shichijo, The University of Tokyo
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 790~793th words in NTSC • ID: 1word inserted at 794th word. Composed with line number and field number Naohiro Shichijo, The University of Tokyo
Serial Data Transport Interface (SDTI) • 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 • Usually, data packets will carry compressed video data E.g. MPEG2 (in D-10), DV (in D-7) etc... Naohiro Shichijo, The University of Tokyo
SDTI Payload Naohiro Shichijo, The University of Tokyo
HDTV formats SMPTE 274M SMPTE 293M Naohiro Shichijo, The University of Tokyo
Basic difference with SDTV • Primary Colors • Luma and Chroma equations Naohiro Shichijo, The University of Tokyo
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. Naohiro Shichijo, The University of Tokyo