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1、 AS 4806.32006 Australian Standard Closed circuit television (CCTV) Part 3: PAL signal timings and levels AS 4806.32006 Accessed by MONASH UNIVERSITY LIBRARY on 09 Oct 2006 This Australian Standard was prepared by Committee EL-051, Non-Broadcast Television. It was approved on behalf of the Council o
2、f Standards Australia on 22 May 2006. This Standard was published on 21 June 2006. The following are represented on Committee EL-051: Australian Communications and Media Authority Australian Federal Police Australasian Railway Association Engineers Australia Australian Security Industry Association
3、National Security Association of Australia Society of Motion Picture and Television Engineers Keeping Standards up-to-date Standards are living documents which reflect progress in science, technology and systems. To maintain their currency, all Standards are periodically reviewed, and new editions a
4、re 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 Standards may also be withdrawn.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
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7、courage readers to notify us immediately of any apparent inaccuracies or ambiguities. Contact us via email at mailstandards.org.au, or write to the Chief Executive, Standards Australia, GPO Box 476, Sydney, NSW 2001. This Standard was issued in draft form for comment as DR 05407. Accessed by MONASH
8、UNIVERSITY LIBRARY on 09 Oct 2006 The Standard is downloaded from Standard Sharing AS 4806.32006 Australian Standard Closed circuit television (CCTV) Part 3: PAL signal timings and levels First published as AS 4806.32006. COPYRIGHT Standards Australia All rights are reserved. No part of this work m
9、ay 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, Australia ISBN 0 7337 7524 1 Accessed by MONASH UNIVERSITY LIBRARY on 09 Oct 2006
10、 AS 4806.32006 2 PREFACE This Standard was prepared by the Standards Australia Committee EL-031, Intruder Alarm Equipment 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
11、television (CCTV) signal timings and levels. The CCTV PAL signal timings and levels given in this Standard are based on the Australian Communications and Media Authority Technical Planning Guidelines. Accessed by MONASH UNIVERSITY LIBRARY on 09 Oct 2006 The Standard is downloaded from Standard Shar
12、ing 3 AS 4806.32006 CONTENTS Page 1 SCOPE4 2 REFERENCED DOCUMENTS4 3 PAL VIDEO CHARACTERISTICS.4 Accessed by MONASH UNIVERSITY LIBRARY on 09 Oct 2006 AS 4806.32006 4 Standards Australia .au STANDARDS AUSTRALIA Australian Standard Closed circuit television (CCTV) Part 3: PAL signal timings and levels
13、 1 SCOPE This 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 DOCUMENTS The following documents are referred to in this Standard: ACMA Australian Communication and Media A
14、uthority Technical Planning Guidelines for the Planning of Individual Services that use the Broadcasting Services Bands ITU-R International Telecommunications UnionRadiocommunication BT.470 Conventional analogue television systems 3 PAL VIDEO CHARACTERISTICS 3.1 General Equipment used in closed circ
15、uit 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 Scanning 3.2.1 General Clause 3.2 specifies the timing intervals of the video signal and Figure 1 illustrates this relationship. 3.
16、2.2 Aspect ratio The aspect ratio of the television picture shall be four units horizontally to three units vertically (4:3). 3.2.3 Scanning sequence During active scanning intervals, the scene shall be scanned from left to right horizontally, and from top to bottom vertically, at uniform velocities
17、 (as seen when sitting in front of a CCTV monitor). 3.2.4 Number of lines and interlacing The number of scanning lines per picture shall be 625, interlaced two to one (2:1). 3.2.5 TV frame and TV field frequencies The nominal television frame (TV frame) and television field (TV field) frequencies sh
18、all 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. Accessed by MONASH UNIVERSITY LIBRARY on 09 Oct 2006 The Standard is downloaded from Standard Sharing 5 AS 4806.32006 .au
19、 Standards Australia 3.2.6 Line frequency The television line (TV line) frequency shall be 15 625 Hz. 3.2.7 Colour burst The colour subcarrier frequency (colour burst) shall be 4 433 618.75 5 Hz. There shall be 10 colour burst cycles on each TV line, with a 180 reversal of phase for each next TV lin
20、e (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 1. 3.2.9 Composite burst video signal (CVBS) The CVBS is comprised
21、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 1. 3.2.10 Video signal leve
22、ls (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
23、 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 in
24、tervals of the video signal and Figure 1 illustrates this relationship. 3.2.11 Colour picture signal Coding 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 chromi
25、nance component, with the phase of the latter component being changed by 180 on alternate lines. 3.2.12 Colour difference signals A 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 luminanc
26、e 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 signals The colour difference signals shall be limited in bandwidth
27、 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 above 4.0 MHz. Accessed by MONASH UNIVERSITY LIBRARY on 09 Oct 2006 AS 4806.32006 6 Standards Australia .au 3.2.14
28、Colour synchronization A 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 subca
29、rrier 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 nin
30、e 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. The phase of the subcarrier burst relative to the U E + signal referenc
31、e phase axis shall be +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 colo
32、ur burst may be suppressed. 3.2.15 Optional signals in the vertical blanking interval Lines 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 fo
33、r 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 bandwidth Colour and/or mon
34、ochrome CCTV system analogue video bandwidth shall be at least 6 MHz 3 dB. NOTE: This bandwidth applies to analogue CCTV equipment and systems. 3.3 PAL video signal timing intervals Parameter Measurement Tolerance Frame rate 25 Hz See Note Field rate (V) 50 Hz See Note Number of lines per frame 625
35、Line rate 15 625 Hz See Note Line period (H) 64 s See Note Line blanking 12 s +0.0, 0.3 s Front porch 1.5 s +0.3, 0.0 s Line synchronizing pulse interval 4.7 s 0.2 s Field blanking interval 25 H + 12 s +0.0, 0.3 s Duration of field synchronizing pulse sequence 2.5 H Duration of pre-equalizing pulse
36、sequence 2.5 H Duration of post-equalizing pulse sequence 2.5 H Accessed by MONASH UNIVERSITY LIBRARY on 09 Oct 2006 The Standard is downloaded from Standard Sharing 7 AS 4806.32006 .au Standards Australia Parameter Measurement Tolerance Duration of equalizing pulse 2.35 s 0.1 s Interval between fi
37、eld synchronizing pulse 4.7 s 0.2 s Colour subcarrier burst Start from leading edge of synchronizing pulse 5.6 s 0.1 s Duration (nominally 10 cycles) 2.25 s 0.25 s Duration of burst blanking pulse (per field) 9 H Build-up time (10% to 90% amplitude points) Edges of: Blanking pulses 0.3 s 0.1 s Synch
38、ronizing signals 0.3 s 0.1 s NOTE: 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 receivi
39、ng devices should operate correctly with tolerances of 0.02%. 3.4 Video signal voltage levels Parameter Nominal value Tolerance Sync tip to reference white 1 V p-p 16% Blanking to reference white 0.7 V p-p 10% Sync tip to blanking 0.3 V p-p 30% Colour burst amplitude 0.3 V p-p 30% Sync to tip yellow
40、 chrominance amplitude (100% colour bars) 1.25 V p-p 20% NOTES: 1 No 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 th
41、e 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. 2 The Aus
42、tralian Communications and Media Authority is responsible for their Technical Planning Guidelines for the Planning of Individual Services that use the Broadcasting Services Bands, which is a variant of the PAL B system described in ITU-R Recommendation BT.470. The variations are (a) depth of vision
43、carrier modulation (broadcast RF transmissionnot relevant for CCTV); (b) use of lines in the vertical blanking interval for vertical interval test signals (VITS) and teletext (generally not used in CCTV); (c) group delay pre correction (broadcastnot relevant for CCTV); and (d) sound carrier 5.5 MHz
44、(generally not used in CCTV). Accessed by MONASH UNIVERSITY LIBRARY on 09 Oct 2006 AS 4806.32006 8 Standards Australia .au 3.5 PAL B signal timing chart PAL B signal timing is shown in Figure 1 308309310311312313314315316317318319320321 621622623624625123456789 621622623624625 1234567 89 64 s Four-f
45、ield sequence burst blanking 9 Lines burst blanking First field Second field Third field Fourth field Lines Lines 308309310311312313314315316317318319320321Lines Blanking level Black level White level VD Field blanking (25 lines + line blanking) Up to line 336 for even fields Up to line 23 for odd f
46、ields Colour burst phase 75 Colour burst phase 225 First field (odd) Third field Fourth field Second field (even) White level (0.7 V) Black level Blanking level (0 V) Sync level (-0.3 V) Field sync start Line blanking interval 12.00 s (+0.0;-0.3 s) Sync + burst porch 5.6 s ( 0.1 s) Line sync pulse 4
47、.7 s ( 0.2 s) 0.3 V 0.7 V 0.3 V 2.25 s ( 0.25 s) Colour sub-carrier burst (4.43 MHz) 10 cycles TV line duration = 64 s = H Active line = 52 s 5 Equalizing pulses (each 2.35 s) (2.5 lines) 5 Field sync broad pulses (each 4.7 s) (2.5 lines) 5 Equalizing pulses (each 2.35 s) (2.5 lines) FIGURE 1 PAL B
48、SIGNAL TIMING CHART Accessed by MONASH UNIVERSITY LIBRARY on 09 Oct 2006 The Standard is downloaded from Standard Sharing 9 AS 4806.32006 .au Standards Australia 3.6 Phase of burst U E + and V E + signals The phase of burst U E + and V E + signals are shown in Figure 2. +90 -90 Burst phase line n Burst phase line n + 1 Line n: Odd lines of the first and second fields Even lines of the third and fourth fields E V E U E U E V 135 135 FIGURE 2 PAL COLOUR BURST VECTORS Accessed by MONASH UNIVERSITY LIBRARY on 09 Oct 2006 AS 4806.32006 10 Standards Austra