Video Basics ---Major Ref

Video Basics ---major ref. From Ch.5 of textbook 2 ■ Introduction ---- video industry ■ Video Imaging ---- video scan, aspect ratio ■ Color and Composite & component systems ■ From Analog To Digital Video ■ Spatial Conversions ---- video formats ■ Temporal Conversions ■ Mixing And Keying @NTUEE 1 DSP/IC Lab Video Environments Satellite DVB-S downstream(max 90 Mbps) DSS Cable Modem Cable Network DVB-C downstream(max 40 Mbps) OpenCable Home Connection DSTB IEEE 1394 / USB Ethernet 10 Mbps….. Terrestrial DVB-T/ ATSC (Plug&Play , high-data-rate) Interaction Channel DTV set DirecPC/ DirecDuo (1-way / 2-way)1. Satellite( fast PSTN/ ISDN 2. Cable Modem ( QPSK, TCP / IP for PSTN/ ISDN modem 3. SDSL / ADSL / VDSL ….. @NTUEE 2 DSP/IC Lab 1 Video Service Environments Service Provision HFC POTS Wireless Cable DVB-S DVB-C (Full Service (xDSL access) (MMDS) DVB-T (high speed BB) (Cable Modem) Network) TCP / IP Hybrid Services DSTB Residential LAN (IR, RF, Wired) @NTUEE 3 DSP/IC Lab F ãñìµ@ûì > r Gï=.1 *<ÎPU½ÿ½CD *¶1nñG *ÐÍV PC ;^éuu *ñ<uïÚí Internet w7Home SpoppingHome Banking…. *PPV 2âSaDO"H2<_G.(VOD)ÛÚí ö^éGï=. *ö7GïA2Uf÷ ß[1nÐ¯rn1<t *>1Êº=.²ÁÞ+Gï STBw¯Gï=.1Æ *"Gï=.²2òGï STB Þ1äh¼oZÐõ1"2¤ Gï STB aöÞ^éGï=.> * õ1n<tñ)ËàÁréï=éC 4 *Gï>h Úü¶Êº=.AÓ-I FMMedium Wave ¤µÚí1 / R *Gï>Áä÷1 transm ittersÇt1ä÷ *Gï>r1ñ² ô<Gï=.> *Î BBC aGï=.Ú7ÂbÍÈzéúrp¾câ> DTT > *BDB 2£< 30! DTT nÚí *~£U>;HÞr> HDTV/SDTV > *BSkyB ~£ 6 ´[uSr> 200 !nGïá#Úí *TCIComcastÛUÀ MSOb 1997 £¦¬[àGï Cable Úí *Flextech $} BBC >Ë1Gïn(å UKFM) ö´^éGï=.> *1994 £¦Gï DBS I 1996 £¦[JGïá#r> *1997£¦Gï Cable Úír> *1998 £Î DTT r>Êº=.²ñhk¶ 12ß 15£1´t Ngñ·ëæJUJT702::9 @NTUEE 4 DSP/IC Lab 2 Applications of Digital Video ¸®ñ *Î]]XÇæ *Internetÿñ *ñ'$7Åg e-mailì½WWW... *pÊTÊÅg * ³yìhome banking *PPV(Pay-TV) ...... RC Set-Top Box x+ *ÌFû1Dñ VOD/NVODìmultimedia- * ò@(Video Telephone) on-demandìKODìÌF *x ò ìÌFmì5Fm ì~7J *ò¦éÙ *...... .....) @NTUEE 5 DSP/IC Lab Benefits of Digital Video i) Open Architecture video systems, meaning the existence of video at multiple spatial, temporal, and SNR resolutions within a single scalable bitstream ii) Interactivity iii) Variable-rate transmission on demand iv) Easy software conversion from one standard to another v) Integration of various video applications vi) Editing capabilities, such as cutting and pasting, zooming removal of noise and blur vii) Robustness to channel noise and ease of encryption viii) …... @NTUEE 6 DSP/IC Lab 3 Wireless Broadcast Video 8z(Satellite) ÝVm(Terrestrial) 5Y(MMDS,MVDS,LMDS) F ò MPEG-2 MP@MLÿ MPEG-2 MP@MLî MPEG-2 MP@MLÿ 5ï DigiCipher IÿII MPEG-2 MP@HL(HDTV) DigiCipher II F > ð ÿ ëÃo 5J9 QPSK VSB( ) QAM QPSK OFDM(²) ÝÍÅÕÃ ïo@ ¸ Y RÒñ ÌFû return path ò®ægû( EPG)ìVBIÕÃìVideo Info.2ÌNò1D DirecTV/USSB,PrimeStar,EchoStar, •f‘98úäDTTÉ Cross Country Cable of Riverside, AlphaStar,ASkyB,PerfecTV’JSkyB, %f ú É Tele-TV(Bell Atlantic,Nynex,Pacific ë f DirecTV( ),²(Canal+, BSkyB,DT, • ‘98 10 DTT Telesis)...... FilmNet....),KoreaSat,M-Net(Ñ).... 1D Ngñ·ëæJUJT702::9 @NTUEE 7 DSP/IC Lab Future Video Systems Satellite SDRAM VCXO Dual QPSK RF Tuner ADC Demod FEC Modulator IF RGB or Y/C and CVBS QPSK FEC Descrambler OSD NTSC/PAL Mod AND/OR Encoder Cable QAM MPEG-2 SECAM Tuner ADC FEC Encoder AV Demod Video MPEG-2 IF (optional) Switch Audio AND/OR Terrestrial L Traffic DACs COFDM Transport Graphics Tuner ADC Demod FEC Controller + Filters R CPU SDRAM I2C Flash/ Digital Decoder Chip EPROM IR Buffer Modem Smart Card P1394 & Amp RS232 IrDA Port V-Series Buffer P1284 SCSI @NTUEE 8 DSP/IC Lab 4 ÑfÝF ¨ n Gïá#(DST) Gï Cable(DCT) ÿ>(DTT) [Jz DVB-S DVB-C DVB-T/COFDM DSSDVB-S SCTE-031 ATSC/8-VSB ãU DVB-S --- ATSC/8-VSB ²! DVB-S DVB-C DVB/COFDM (6MHz) DVB-S --- ATSC/8-VSB ¾J DVB-S --- DVB-T m DVB-S DVB-C ATSC/8-VSB U DVB-S DVB-C ATSC/8-VSB @NTUEE 9 DSP/IC Lab EUWÇÍS` ¾bÍ‘98‘98£1111´11²%¤r>DTV ¾ÎbÍ‘98‘98£1111´1515²%¤r>DTV (Ondigital/BDB) ¾²!2Í20032003£r>ISDB(ISDB(6AudioVideoData) £ 1998 2000 2002 2004 2006 2008 2010 ¯Ê ºn rh 30!UÄ > > Cà2009£ O÷50%´ ¯NTSC À¬s¯ rh Êºn´Z > ¯Ê ß Uþ d ºn ôr> ôr> r> ÷±-`Ã=¬IT ISà½1998.11 @NTUEE 10 DSP/IC Lab 5 ÑfEUWÇÍ 5 ë 1997 1998 1999 2000 2001 2002 2006 *Y«`Ó1÷ *Y«dô>(1 ´) ; *^é2`Óâ *â>â>(6 ´) * ¯ NTSC *rhçm¤ô>(12 ´) n *GsÓ-Q7(ATSC) u *â>nu½n» *Y«>=.%% *â>Úí *þï> Úí *DTT Úí VÊºÚíu¡> Úí *ÑD=.Úí *}GÚí /uïÚí 1997 1998 1999 2000 2001 2002 2006 ÷±-`Ã=¬IT ISà½1998.11 @NTUEE 11 DSP/IC Lab Ñf ò·g)TUC*ÍºÅ F F Terrestrial STB Cable STB FSatellite STB C¹â/ânO¬Ì C¹½YnO¬Ì, CnO·ì²ì?¡ ì²ì]òìæì?¡ »Ñ, C... ì ]òìIì 7µìâe ì¦ì6ØìyAìA Cr7Û7µìI ìf2ìæì»ÑìC ì]òìâeì· ì¿ìeW Aë9F(CCL)SÏ ATSCÕÃtf O 18000 25% 16000 zàf dúñf 20% 14000 ¾ £ þzà 12000 zpñþ¶÷ ¾‘98 £DST STB þzà 15% ‘98 DST STB 10000 ff 8000 10% pp93.4% 6000 93.4% 3730 4000 2465 5% 1670 ¾‘99£2¶fDTT STBá 2000 90 580 ¾‘99£2¶fDTT STBá 0 0% ââ 1997 1998 1999 2000 2001 Ng:·ëæITISYgJ,1998/10 @NTUEE Understanding & Solutions/1998.8 12 DSP/IC Lab 6 fDbcmfg×F¬¨ Item Schedule Tasks / Objects Vendors Participation MCNS- '96.7 *broadband Cable Modem Follow ADC,Bay Networks,3Com,Com21,Cisco,GI,Motorola,NEC, '97.8¨ë (interoperability) NetGame,Panasonic,Phasecom,S-A, Samsung,Sony, Terayon, DOCSIS Thomson CE,Toshiba…….. '97.8RFI *next-generation digital STB(include Microsoft; GI; S-A Group( IBM,Pioneer,PowerTV,Sun,Toshiba); '97.1023 proposals MCNS CM) Intel Group(Cisco,Netscape,NCI,Oracle,Thomson CE); '98.5NCTAÍÄ *Open architecture(RTOSs / APIs / Intel/NCI; Oracle/NCI/Netscape; Thomson CE/NCI; Cisco; Sony; Thomson Sun(OpenTV); Samsung; Pioneer Digital Technologies; OpenCable ºø?7 microprocessors) ACTV/Sarnoff; IBM; Criterion Software; Lucent Technologies; '98ä±ÿY *exiting open Internet specifications Y *'98.3 specified -- IEEE1394(1úÚ) SCM Microsystems; Zenith Electronics; Worldgate Communications; Texas Instruments; Wink Communications; Panasonic '97.10 es * the specs will establish a data packet network 3Com; 8x8; Ascend; Bay Networks; Cisco; eFusion; Ericsson; PacketCable±Þ9-12 Ú?Ô for interactive services(carry IP Internet traffic, Fore Systems; IBM; Intel/Lucent Team; Inter-Tel; Linkon; Mediatrix nOÍ Peripherals; Motorola; NEC; Netspeak; Nortel; S-A; Siemens/Com21 IP voice telephony,video,teleconferencing) Team; Sony; Sun; Vienna & video over Cable are moving Cable forward in the race to full 2-way ,IP capable networks provide consumer broadband services by the year 2000 ÷±-CableLabs`Ã=¬ITISà½/1998 @NTUEE 13 DSP/IC Lab Video Imaging Imaging: normal photography, X-rays, electronic documents, electronic still pictures, motion pictures, TV Video: a sequence of still pictures of a scene taken at various subsequent intervals in time Scanning: a form of sampling of a continuously varying two-dimensional signal @NTUEE 14 DSP/IC Lab 7 Video Resolution Viewing Ratio (VR): VR = d /PH d= viewer’s distance from the screen PH= picture height Visible pixels = 3440 /VR Pixel (Pel) : the smallest detail that can be reproduced in a picture is about the size of a picture element Minimum Viewing Rates System Line or pixels/PH VR NTSC television 483 7.2 HDTV 1080 3.2 Computer display 768 <4.5 @NTUEE 15 DSP/IC Lab Refresh Rate and Flicker Persistence of vision, causes the visual system responds slowly to rapid changes of illumination Flicker: if the illumination varies cyclically at a low frequency, the eye may perceive an annoying effect Refresh Rate: the light output of display devices decays after a short time, and therefore must be refreshed periodically to maintain the effect of steady illumination Display Refresh Rates System Refresh rate (Hz) Environment VR NTSC television 60(59.94) Living room 7 PAL television 50 Living room 7 Computer display 72 Bright office 1-2 Motion picture theater48 Dark room 5-10 @NTUEE 16 DSP/IC Lab 8 Video Imaging Raster Scan ----(Progressive) @NTUEE 17 DSP/IC Lab Video Imaging Interlace Raster Scan ---- it is the tradeoff of bandwidth, flicker, and resolution ----- may cause flicker problems for text and graphics @NTUEE 18 DSP/IC Lab 9 Image Aspect Ratio IAR is defined as the ratio of picture width to height IAR = w / h PAR (pel aspect ratio) = IAR * vertical_size / horizontal_size : full screen display where horizontal_size is the width of the image in terms of pels and vertical_size is the height of the image in lines ex. Display IAR = 4:3 Image size = 720 pels * 486 lines PAR = 4/3 x 486/720 = 0.9 or IAR * display_vertical_size / display_horizontal_size : portion display @NTUEE 19 DSP/IC Lab @NTUEE 20 DSP/IC Lab 10 Gamma Correction Many TV cameras and all CRT-based displays have a nonlinear relationship between signal voltage and light intensity. B = c v r + b B: light intensity c: gain factor b: cutoff (camera) or black level (CRT) light intensity r: 1 ~ 3.0 To avoid gamma correction circuitry inside millions of TV receivers, gamma correction is done prior to transmission. Ex. Assuming the gamma of camera to be 1 and that of the display to be 2.2, then the camera voltage is raised to a power of 1/2.2 = 0.45. @NTUEE 21 DSP/IC Lab Human visual system ■ The retina consists of receptors sensitive to light called photoreceptors connected by nerve cells.

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