【AS澳大利亚标准】AS 4806.3-2006 Closed circuit television (CCTV) Part 3 PAL signal timings and levels.doc

as 4806.32006accessed by monash university library on 09 oct 2006as 4806.32006australian standardclosed circuit television (cctv)part 3: pal signal timings and levelsthis australian standard was prepared by committee el-051, non-broadcasttelevision. it was approved on behalf of the council of standards australia on22 may 2006.this standard was published on 21 june 2006.the following are represented on committee el-051: australian communications and media authorityaustralian federal policeaustralasian railway associationengineers australiaaustralian security industry associationnational security association of australiasociety of motion picture and television engineerskeeping standards up-to-datestandards are living documents which reflect progress in science, technology and systems. to maintain their currency, all standards are periodically reviewed, and new editions are published. between editions, amendments may be issued. standards may also be withdrawn. it is important that readers assure themselves they are using a current standard, which should include any amendments which may have been published since the standard was purchased.detailed information about standards can be found by visiting the standards web shop at .au and looking up the relevant standard in the on-line catalogue.alternatively, the printed catalogue provides information current at 1 january each year, and the monthly magazine, the global standard, has a full listing of revisions and amendments published each month.accessed by monash university library on 09 oct 2006australian standardstm and other products and services developed by standards australia are published and distributed under contract by sai global, which operates the standards web shop.we also welcome suggestions for improvement in our standards, and especially encourage readers to notify us immediately of any apparent inaccuracies or ambiguities. contact us via email at .au, or write to the chief executive, standards australia, gpo box 476, sydney, nsw 2001.the standard is downloaded from standard sharingthis standard was issued in draft form for comment as dr 05407.as 4806.32006accessed by monash university library on 09 oct 2006australian standardclosed circuit television (cctv)part 3: pal signal timings and levelsfirst published as as 4806.32006.copyright standards australiaall rights are reserved. no part of this work may be reproduced or copied in any form or by any means, electronic or mechanical, including photocopying, without the written permission of the publisher.published by standards australia gpo box 476, sydney, nsw 2001, australiaisbn 0 7337 7524 13as 4806.32006prefacethis standard was prepared by the standards australia committee el-031, intruder alarmequipment and installations. this is a new joint australian/new zealand standard.the objective of this standard is to provide requirements for phase alternating line (pal)closed circuit television (cctv) signal timings and levels.the cctv pal signal timings and levels given in this standard are based on the australianthe standard is downloaded from standard sharingaccessed by monash university library on 09 oct 2006communications and media authority technical planning guidelines.accessed by monash university library on 09 oct 2006contentspage1scope .4 2referenced documents . 43pal video characteristics . 49as 4806.32006the standard is downloaded from standard sharingstandards australiaaustralian standardclosed circuit television (cctv)part 3: pal signal timings and levels1 scopethis standard provides requirements for pal signals used in closed circuit television(cctv) equipment and systems with an analogue input or an analogue output or both.2 referenced documentsthe following documents are referred to in this standard: acmaaustralian communication and media authoritytechnical planning guidelines for the planning of individual services that use thebroadcasting services bandsitu-rinternational telecommunications unionradiocommunicationbt.470conventional analogue television systems3 pal video characteristics3.1 generalequipment used in closed circuit television (cctv) systems with an analogue input and/or an analogue output should comply with the cctv pal signal timings and levels specified in this standard.3.2 scanning3.2.1 generalclause 3.2 specifies the timing intervals of the video signal and figure 1 illustrates this relationship.accessed by monash university library on 09 oct 20063.2.2 aspect ratiothe aspect ratio of the television picture shall be four units horizontally to three units vertically (4:3).3.2.3 scanning sequenceduring active scanning intervals, the scene shall be scanned from left to right horizontally, and from top to bottom vertically, at uniform velocities (as seen when sitting in front of a cctv monitor).3.2.4 number of lines and interlacingthe number of scanning lines per picture shall be 625, interlaced two to one (2:1).3.2.5 tv frame and tv field frequenciesthe nominal television frame (tv frame) and television field (tv field) frequencies shall be 25 hz and 50 hz respectively, and equal to the appropriate submultiples (625 and 312.5 respectively) of the line frequency. two subsequent tv fields make up one tv frame. standards a.auaccessed by monash university library on 09 oct 20063.2.6 line frequencythe television line (tv line) frequency shall be 15 625 hz.3.2.7 colour burstthe colour subcarrier frequency (colour burst) shall be 4 433 618.75 5 hz. there shall be10 colour burst cycles on each tv line, with a 180 reversal of phase for each next tv line(phase alternating linepal).3.2.8 composite video signal (cvs)the cvs is comprised of the active video information (luminance signal) and the horizontal and vertical synchronizing pulses occurring alternately, as shown in figure composite burst video signal (cvbs)the cvbs is comprised of the active video information (luminance signal), and horizontal and vertical synchronizing pulses occurring alternately, together with the colour components (chrominance signal), referenced to the colour burst at the beginning of each active tv line, as shown in figure 0 video signal levels (amplitude)the nominal synchronizing pulse amplitude shall be 300 mv, tip negative.the nominal luminance signal amplitude shall be not more than 700 mv, measured from the blanking level.black representation shall be at around 0 mv from the blanking level, while white representation shall be at the peak of 700 mv. all other luminance representations are between 0 mv and 700 mv.all video signal levels shall be measured when the video source is terminated with the correct matching load (e.g., 75 for sources designed for use with cctv coaxial cable).note: clause 3.3 specifies the timing intervals of the video signal and figure 1 illustrates this relationship.3.2.11 colour picture signalcoding of the colour information shall be in accordance with the phase alternating line (pal) system. in this system the colour picture signal contains a luminance component and a simultaneous chrominance component, with the phase of the latter component being changed by 180 on alternate lines.3.2.12 colour difference signalsa colour difference signal is a video colour signal made by subtracting luminance (y) from one of the colour information signals (rgb) and then inserted into the luminance signal using quadrature modulation (qm). it is usually referred to as r-y and b-y. the g-y colour difference signal is not created because it can be reconstructed from the other three signals.3.2.13 bandwidth of colour difference signalsthe colour difference signals shall be limited in bandwidth prior to modulation of the colour subcarriers by a circuit having an approximate gaussian response, with an attenuation of not more than 3 db at 1.3 mhz, but greater than 20 db at and above4.0 mhz.3.2.14 colour synchronizationa burst of 10 cycles of the colour subcarrier frequency shall occur during each line blanking period, commencing nominally 5.6 s after the half amplitude point of the leading edge of the line synchronizing pulse. at the point of encoding the peak-to-peak amplitude of the subcarrier burst shall be 300 mv and thereafter the amplitude and phase of the burst shall be preserved relative to the chrominance signal. the envelope of the subcarrier burst signal shall have a build-up time consistent with the bandwidth restriction of the colour difference signals.there shall be nine lines of burst blanking starting at or before the beginning of each field blanking interval in a four-field sequence, as illustrated by figure 1.note: the phase sequence of the colour subcarrier burst is detailed in figure 1.e+uthe phase of the subcarrier burst relative to the signal reference phase axis shall bethe standard is downloaded from standard sharing+135 on odd lines of the first and second fields and on even lines of the third and fourth fields, and 135 on even lines of the first and second fields and on odd lines of the third and fourth fields, as shown in figure 2.during the transmission of monochrome signals, the colour burst may be suppressed.3.2.15 optional signals in the vertical blanking intervallines 10 to 22 and lines 323 to 335 may be transmitted for such purposes as control of equipment, source identification, data transmission and circuit performance testing.lines 17, 18, 330 and 331 are preferred for circuit performance testing purposes. teletext signals on lines 21 and 334 shall be restricted to closed-caption services.lines 22 and 335 are preferred for the measurement of noise (i.e., only blanking level should be transmitted on these lines).3.2.16 analogue video bandwidthcolour and/or monochrome cctv system analogue video bandwidth shall be at least6 mhz 3 db.note: this bandwidth applies to analogue cctv equipment and systems.accessed by monash university library on 09 oct 20063.3 pal video signal timing intervalsparametermeasurementtoleranceframe rate25 hzsee notefield rate (v)50 hzsee notenumber of lines per frame625line rate15 625 hzsee noteline period (h)64 ssee noteline blanking12 s+0.0, 0.3 sfront porch1.5 s+0.3, 0.0 sline synchronizing pulse interval4.7 s0.2 sfield blanking interval25 h + 12 s+0.0, 0.3 sduration of field synchronizing pulse sequence2.5 hduration of pre-equalizing pulse sequence2.5 hduration of post-equalizing pulse sequence2.5 hparameter measurementtolerance duration of equalizing pulse2.35 s0.1 s interval between field synchronizing pulse 4.7 s0.2 scolour subcarrier burststart from leading edge of synchronizing pulse 5.6 s 0.1 s duration (nominally 10 cycles)2.25 s0.25 s duration of burst blanking pulse (per field) 9 hbuild-up time (10% to 90% amplitude points) edges of:blanking pulses 0.3 s0.1 ssynchronizing signals 0.3 s0.1 snote: the tolerances on frequency and timing for video signals above are based on aba technical guidelines. for practical cctv applications, broader tolerances are allowable. for video source devices (e.g., cameras), a tolerance 0.015% is deemed acceptable. video receiving devices should operate correctly with tolerances of 0.02%.3.4 video signal voltage levelsparameter nominal value tolerance sync tip to reference white1 v p-p16% blanking to reference white0.7 v p-p10%sync tip to blanking0.3 v p-p30%colour burst amplitude0.3 v p-p30%sync to tip yellow chrominance amplitude(100% colour bars)notes:1.25 v p-p20%accessed by monash university library on 09 oct 20061no voltage level tolerances are specified by the australian broadcasting authority but the tolerances above have been found satisfactory for most cctv applications. these tolerances refer to a full 1 v p-p video signal generated at the source, and terminated with 75 impedance.in a cctv system it is expected that all analogue cctv signals generating levels as shown above are brought to the recipient end with adequate amplification and/or equalization so that the signal parameters fall within the tolerances shown above.2the australian communications and media authority is responsible for their technical planning guidelines for the planning of individual services that use the broadcasting services bands,whichisavariant ofthe pal b systemdescribed initu-r recommendation bt.470.the variations are(a)depth of vision carrier modulation (broadcast rf transmissionnot relevant for cctv); (b)use of lines in the vertical blanking interval for vertical interval test signals (vits) andteletext (generally not used in cctv);(c)group delay pre correction (broadcastnot relevant for cctv); and(d)sound carrier 5.5 mhz (generally not used in cctv).3.5 pal b signal timing chartpal b signal timing is shown in figure 1w h i t e l e ve l ( 0 .7 v ) bla ck le v e lb l a n k i n g l e ve l ( 0 v )64 sfie ld blank ing ( 2 5 line s + line blank ing ) u p t o l i n e 3 3 6 fo r eve n f i e l d su p t o l i n e 2 3 fo r o d d f i e l d sfirst f i e ld ( odd) colour burst phase 75 colour burst phase 2 25 s y n c l e ve l (- 0 . 3 v )62 1 622 62 3 624 62 5 12 3 4 5 6 7 8 9se cond f i e ld (e v e n) li n e s3 0 8 3 0 9 310 311 312 313 314 315 316 317 3183193 2 03 21th i r d fi el dli n es 62 162262 3 62462 512 3 4 5 6 789 fie ld sy n csta r tfo u r th f i e l dli n es 3 0 8 3 0 9 310 311 312 313 314 315 316 317 3183193 2 03 215 eq u a l i z i n g pulse s(e a c h 2. 3 5 s ) ( 2. 5 line s )5 f i e l d s y n c br oad pulse s (e a c h 4.7 s ) ( 2. 5 line s )5 eq u a l i z i n g pulse s( e ac h 2. 35 s ) ( 2. 5 line s )f o ur- f ie ld seque n ce burst blank i ng 9 l i n e s b u r s t b l a n k i n gfirst f i e l dsecond f i eld t hir d f i e l dfo u r th f i e l dwhit e le v e lli n e b l an ki n g i n t er v al 12 .0 0s (+ 0.0;- 0. 3s) 0.7 vsync + b u rs t por c h5 . 6s ( 0 .1s )0. 3 vbla ck le v e lblank i ng le v e lvd accessed by monash university library on 09 oct 20060. 3 vli n e s y n c pulse 4.7 s( 0 . 2 s )t v l i n e d u r a ti o n = 6 4s = h ac ti ve l i n e = 5 2s2 . 2 5 s ( 0 . 2 5s )colo ur s u b-carrier b u rs t( 4 . 4 3 m h z) 10 c y c l e sthe standard is downloaded from standard sharingfigure 1 pal b signal timing chart3.6 phase of burst e u+ signalsthe phase of burst e u+ signals are shown in figure 2.accessed by monash university library on 09 oct 2006e vburst phase line n135 +90 e u-90 e u135 burst phase line n + 1e vline n: odd lines of the first and second fields even lines of the third and fourth fields figure 2 pal colour burst vectors3.7 pal colour vectorspal colour vectors are shown in figure 3.e vrcy gmg +135 ylbe uyl 135 be uthe standard is downloaded from standard sharinggmg rcy legend:e vr, r= red g,g= green b, b= blue cy, cy = cyan mg, mg = magenta accessed by monash university library on 09 oct 2006yl, yl= yellow figure 3 pal colour vectors11as 4806.32006accessed by monash university library on 09 oct 2006notesas 4806.32006the standard is downloaded from standard sharingaccessed by monash university library on 09 oct 2006notesaccessed by monash university library on 09 oct 2006standards australiastandards australia is an independent company, limited by guarantee, which prepares and publishes most of the voluntary technical and commercial standards used in australia. these standards are developed through an open process of consultation and consensus, in which all interested parties are invited to participate. through a memorandum o