SANS 1584-1-2008 Television transmissions Part 1 Terrestrial television transmissions《电视传输 第1部分 地面电视传输》.pdf

1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21131-8 SANS 1584-1:2008Edition 1.1Any reference to SABS 1584-1 is deemed to be a reference to this standard(Government Notice No. 1373 of

4、 8 November 2002)SOUTH AFRICAN NATIONAL STANDARD Television transmissions Part 1: Terrestrial television transmissions Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Stand

5、ards South Africa SANS 1584-1:2008 Edition 1.1 Table of changes Change No. Date Scope Amdt 1 2008 Amended to change the designation from SABS to SANS, with no technical changes. Foreword This South African standard was approved by National Committee StanSA TC 74, Communication technology, in accorda

6、nce with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. The text of the standard Specification of television standards for 625-line system I transmissions in the Republic of South Africa (published by the SABC) was accepted by the committee as suitable for

7、 publication, without technical modification and with limited language editing, as a South African standard, with the addition of a cover page and a foreword. This document was published in May 2008. This document supersedes SABS 1584-1:1994 (first edition). SANS 1584 consists of the following parts

8、 under the general title Television transmissions: Part 1: Terrestrial television transmissions Part 2: Teletext transmissions (withdrawn) Part 3: NICAM transmissions Part 4: Direct-to-home analogue satellite broadcasting (withdrawn). Annexes A to D form an integral part of this document. SANS 1584-

9、1:2008 Edition 1.1 1 Introduction The purpose of this part of SANS 1584 is to specify the PAL colour television system in accordance with the 625-line system I and to indicate some of the tolerances permitted in the generation, processing and transmission of the signal. Clauses 2 and 3 are concerned

10、 with the system characteristics of the vision signals, including specification of the synchronizing and blanking waveforms. Clause 4 specifies the form of the picture information of the vision signal, while clause 5 describes the synthesis of colour picture information from the red, green and blue

11、signal voltages in a colour camera. Clause 6 specifies the ideal radio frequency characteristics of the sound and vision components. Annex A presents information on the various types of colour bar signal used for alignment and testing of colour television equipment, with the table showing the amplit

12、udes of the picture components of primary colours and their complements. Annex B reiterates the colour signal identities of clause 5 in matrix form and annex C gives details of the nature and application of the insertion signals. Annex D gives the frequencies and channel numbers that will be used in

13、 the Republic of South Africa. SANS 1584-1:2008 Edition 1.1 2 This page is intentionally left blank SANS 1584-1:2008 Edition 1.1 3 Contents Page Foreword Introduction. 1 1 Scope . 5 2 Video characteristics 5 2.1 Picture signal . 5 2.2 Number of lines per picture . 5 2.3 Interlace . 5 2.4 Aspect rati

14、o . 5 2.5 Gamma 5 2.6 Colour subcarrier frequency 5 2.7 Relationship between colour subcarrier frequency and line scanning frequency . 6 2.8 Field frequency 6 2.9 Video bandwidth 6 3 Synchronizing and blanking waveforms 6 4 Video signal . 9 4.1 Tolerances . 9 4.2 General specification . 9 4.3 Lumina

15、nce component and amplitude/frequency characteristics . 9 4.3.1 Luminance component . 9 4.3.2 Amplitude/frequency characteristics . 9 4.4 Chrominance component 10 4.4.1 Modulation axes . 10 4.4.2 Delay inequality between chrominance components . 10 4.4.3 Chrominance modulation bandwidth 11 4.4.4 Col

16、our display on zero chrominance signal . 11 4.4.5 Residual subcarrier . 11 4.5 Colour synchronizing burst 12 4.5.1 Duration of burst . 12 4.5.2 Amplitude of burst . 12 4.5.3 Position of burst 12 4.5.4 Field interval blanking . 12 4.5.5 Bandwidth of burst 12 4.5.6 Relationship between burst amplitude

17、 and chrominance signal amplitude . 12 4.5.7 Angular position of colour burst 12 4.6 Signal excursions at decoder output . 14 SANS 1584-1:2008 Edition 1.1 4 Contents (concluded) Page 5 Colour signal equations 14 5.1 Primary colour chromaticities 14 5.2 Luminance signal voltage 14 5.3 Colour differen

18、ce signal voltage 15 5.4 Chrominance modulation signal voltage . 15 5.5 Equation for the modulated chrominance signal . 15 5.6 Equation for the complete colour signal 16 6 Radio frequency characteristics . 16 6.1 Channel bandwidth . 16 6.2 Polarization 17 6.3 Asymmetric-sideband vision transmission

19、characteristics 17 6.4 Vision carrier modulation . 17 6.5 Vision carrier envelope 17 6.6 Vision carrier to sound carrier spacing 17 6.7 Vision carrier to sound carrier power ratio 17 6.8 Sound carrier modulation 17 Annex A (normative) Colour bar waveforms . 20 Annex B (normative) Colour signal ident

20、ities 24 Annex C (normative) Insertion signals . 25 Annex D (normative) Radio frequency data 30 SANS 1584-1:2008 Edition 1.1 5 Television transmissions Part 1: Terrestrial television transmissions 1 Scope This part of SANS 1584 specifies the PAL colour television system in accordance with the 625-li

21、ne system I. Certain tolerances permitted in the generation, processing and transmission of the signal are indicated. 2 Video characteristics 2.1 Picture signal The picture signal shall correspond to the scanning of the image at uniform velocities from left to right and from top to bottom. 2.2 Numbe

22、r of lines per picture The number of lines per picture shall be 625. During source synchronizing operations, there may be an addition or a deletion of one line per field for a brief period (1 s to 5 s). 2.3 Interlace The interlace ratio shall be 2 to 1. 2.4 Aspect ratio The ratio of image width to i

23、mage height within the picture area shall be 4 to 3. 2.5 Gamma The gamma of the transmitted signal shall be related to a display gamma of 2,8 0,3. 2.6 Colour subcarrier frequency The colour subcarrier frequency fgcshall be: fgc= 4,43361875 MHz 1,00 Hz. SANS 1584-1:2008 Edition 1.1 6 Where the signal

24、 originates from an overseas source, the tolerance on this frequency may be relaxed to 5 Hz. The maximum rate of change of colour subcarrier frequency shall be 0,1 Hz. During source synchronizing operations, there will be small phase perturbations which may cause the frequency and its rate of change

25、 to deviate beyond these limits for short periods (1 s to 5 s). 2.7 Relationship between colour subcarrier frequency and line scanning frequency The line scanning frequency fhshall be a submultiple of the colour subcarrier frequency, the exact relationship being: 6254135 1gch+=ff With fgcas in 2.6:

26、fh= 15,625 kHz The converse relationship is: fgc= (284 - 0,25) fh+ 25 Hz Under some conditions, where the signal originates from an overseas source or where the reference of synchronism is being changed, this relationship may not apply. Under these conditions: fh= 15,625 kHz 0,02 % (CCIR) and the su

27、bcarrier frequency shall conform to 2.6. 2.8 Field frequency The field scanning frequency shall be: 6252hfieldff= 2.9 Video bandwidth The normal video bandwidth shall be 5,5 MHz. 3 Synchronizing and blanking waveforms The horizontal and vertical synchronizing and blanking waveforms shall be as speci

28、fied in figures 1 and 2, which show a typical signal at the point of origination. The colour burst blanking waveform shall be as described in 4.5.1 and 4.5.2 (see figure 6) and the colour burst position shall be as described in 4.5.3 and as shown in figures A.2 and C.1. SANS 1584-1:2008 Edition 1.1

29、7 NOTE Pulse duration is measured at half-amplitude points. Blanking duration is measured at half-amplitude points with a white level signal of line duration. Figure 1 Typical line showing synchronizing signals .Figure 2 Vertical synchronizing and blanking waveforms for a typical signal 8 SANS 1584-

30、1:2008Edition 1.1 SANS 1584-1:2008 Edition 1.1 9 4 Video signal 4.1 Tolerances The tolerances in this clause apply to the waveform at the point of programme origination, which is defined as all the apparatus in a studio centre, from the coder to the studio centre output, including video tape recorde

31、rs. 4.2 General specification The colour picture signal shall comprise a luminance (brightness) component and a pair of chrominance (colouring) components transmitted simultaneously as the amplitude modulation sidebands of a pair of suppressed subcarriers in phase quadrature that have a common colou

32、r subcarrier frequency as defined in 2.6. The phase of one of these subcarriers is commutated through 180 after the end of each line, yielding a colour signal that conforms to the system generally known as Phase Alternation Line (PAL). A monochrome picture signal contains the luminance (brightness)

33、component only. 4.3 Luminance component and amplitude/frequency characteristics 4.3.1 Luminance component An increase in the incident light intensity shall correspond to an increase in the amplitude of the video signal. For a colour signal, the relationship between the spectral composition of the in

34、cident light and the luminance signal voltage shall be as defined in 5.2. 4.3.2 Amplitude/frequency characteristics The amplitude/frequency characteristics of the luminance signal shall be substantially uniform from 0 MHz to 5,5 MHz, except where it may be modified in the region embracing the colour

35、 subcarrier frequency by the use of a notch filter in the coder (see figure 3). Figure 3 The amplitude/frequency characteristics of the luminance signal showing a possible modification due to a notch filter SANS 1584-1:2008 Edition 1.1 10 Figure 4 The phase of subcarrier representing primary colours

36、 and their complements on alternate lines of the PAL colour system 4.4 Chrominance component The chrominance signal shall correspond to the sideband components of two amplitude modulated subcarriers in phase quadrature. The two modulation axes are generally identified by the letters U (unswitched) a

37、nd V (switched), the polarity of the V axis component being reversed after every line. Colours are thus represented by a subcarrier of a particular amplitude and at one of two phases, depending on the polarity of the V axis modulation. Figure 4 shows the two representations of primary colours and th

38、eir complements, line n corresponding with the odd-numbered lines of the first and second fields and with the even-numbered lines of the third and fourth fields. Line n + 1 corresponds with the even-numbered lines of the first and second fields and with the odd-numbered lines of the third and fourth

39、 fields. 4.4.1 Modulation axes The phase difference (quadrature) between the colour subcarriers that correspond to the two modulation axes shall be as shown in figure 5. The two axes are identified by the letters U and V. The tolerances shown in figure 5 apply to the colour signal at the point of or

40、igination. 4.4.2 Delay inequality between chrominance components The delay inequality introduced in the coder between the two modulated chrominance components shall be less than 5 ns. SANS 1584-1:2008 Edition 1.1 11 Figure 5 The phases of the subcarriers and their modulation axes 4.4.3 Chrominance m

41、odulation bandwidth The bandwidth of the chrominance modulating video signals (see 5.4) shall be constrained by the following conditions: at 1,3 MHz : 20 dB attenuation relative to low frequencies. The form of this characteristic shall be approximately Gaussian. The modulating process shall not modi

42、fy these bandwidths. Nevertheless, the upper chrominance sideband will be subsequently restricted by the nominal video bandwidth of 5,5 MHz. 4.4.4 Colour display on zero chrominance signal It is intended that zero chrominance signal produce a display chromaticity of CIE Illuminant D6500i.e. x = 0,31

43、3 y = 0,329. 4.4.5 Residual subcarrier The peak-to-peak subcarrier level when the chrominance signal is intended to be zero shall not exceed 7 mV in a 700 mV picture. SANS 1584-1:2008 Edition 1.1 12 4.5 Colour synchronizing burst A burst of subcarrier shall be included following the line synchronizi

44、ng pulse, to establish the reference subcarrier phase and to synchronize the switching of the V axis. 4.5.1 Duration of burst The colour burst shall consist of 10 cycles 1 cycle of colour subcarrier. The duration measured between the half-amplitude points on the envelope of the colour burst shall be

45、 2,25 s 230 ns. 4.5.2 Amplitude of burst The peak-to-peak colour burst amplitude (average over two successive lines) shall be three-sevenths of the difference between white and blanking levels. This shall be 300 mV 9 mV ( 3 %) on a signal with a 700 mV white level. The amplitudes of burst on success

46、ive lines shall be within 5 % of one another. 4.5.3 Position of burst The colour burst shall start at 5,6 s 100 ns from the leading edge of the line synchronizing pulse, this time being measured between half-amplitude points. This is detailed in figure 6. 4.5.4 Field interval blanking Colour burst s

47、hall be omitted during nine lines of each field blanking interval, in the manner shown in figure 7. 4.5.5 Bandwidth of burst The pulse used to produce the colour burst shall be subjected to the same bandwidth specification prior to modulation as a chrominance signal (see 4.4.3). This gives an approx

48、imate burst risetime of 300 ns. 4.5.6 Relationship between burst amplitude and chrominance signal amplitude The relationship between the colour burst amplitude and the chrominance signal amplitude shall be accurate to 11 %. This tolerance is required because the amplitude of the colour burst can be

49、used to indicate the intended saturation of the picture. 4.5.7 Angular position of colour burst Relative to the +U modulation axis, on odd-numbered lines of the first and second fields and on even-numbered lines of the third and fourth fields, the phase of the colour burst shall be +135. On even-numbered lines of the first and second fields and on odd-numbered lines of the third and fourth fields, the phase of the colour burst shall be +225. The mean colour burst phase shall be 180 2 from the reference axis (see figure 5). S