1、ITU-T RECMN+N.b7 93 486259L 0583978 208 9 I NTERNATIONAL TELECOMMUNICATION UN ION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU MAINTENANCE OF INTERNATIONAL SOUND-PROGRAMME AND TELEVISION TRANSMISSION CIRCUITS N .67 (03193) MONITORING TELEVISION TRANSMISSIONS - USE OF THE FIELD BLANKING INTE
2、RVAL ITU-T Recommendation N.67 (Previously “CCITT Recommendation”) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN*N-b7 93 4862591 0583979 144 W FOREWORD The ITU Telecommunication Standardization Sector (ITU-T) is a permanen
3、t organ of the International Telecom- munication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WT
4、SC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. ITU-T Recommendation N.67 was revised by the ITU-T Study Group IV (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). NOTES
5、1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the
6、IFRB have been replaced by the Radiocommunication Sector. In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IERB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions
7、 of this Recommendation will contain the proper terminology related to the new ITU structure. 2 telecommunication administration and a recognized operating agency. In this Recommendation, the expression “Administration” is used for conciseness to indicate both a O ITU 1994 All rights reserved. No pa
8、rt of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Servic
9、es8 . . 0583980 . W CONTENTS Monitoring points . Numbering of lines in a television field . 625-line insertion test signals . 525-line insertion test signals . Insertion test signals for MAC systems Measurements on insertion test signals Insertion and removal of test signals in the field blanking pe
10、riod . 7.1 International signals 7.2 National signals General implementation . Page 1 1 1 3 3 9 9 9 10 10 References . 12 Recommendation N.67 (03/93) 1 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN*N-b7 93 m 4862571 058398
11、1 8T2 m ABSTRACT This Recommendation outlines the method of monitoring television transmissions by use of insertion test signals on 525/625-line systems and also on MAC systems. The Recommendation goes on to describe the various types of signals used and the method of insertion and extraction for mo
12、nitoring purposes. Keywords Insertion test signal, monitoring, television transmission. 11 Recommendation N.67 (03/93) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN*N-b7 93 II 4862591 0583982 739 = Recommendation N.67 MONI
13、TORING TELEVISION TRANSMISSIONS - USE OF THE FIELD BLANKING INTERVAL (Published 1968; revised 1972,1976,1980,1984 and 1993) 1 Monitoring points Technical control by the telecommunication Administrations of a television transmission in progress should be possible at any time: - - at national and inte
14、rnational television centres in the connection; at the last staffed-station immediately preceding the frontier of each country and at a point in the station which will include as much as possible of the station equipment in the direction of transmission concerned (by providing monitoring-demodulator
15、s if necessary). These centres and stations should be equipped with an oscilloscope (the horizontal sweep frequency of which is synchronized to the line frequency) for monitoring the electrical signal and a picture-monitor for monitoring the complete picture. In the case of a multiplexed analogue co
16、mponent (MAC) signal, the use of a synchronization extractor will sometimes be necessary to display the electrical signal on an oscilloscope. This is the case for D2 MAC-packet signal. 2 For 625-line systems the numbering of the lines is as follows: Line 1 starts at the instant indicated by O, in Fi
17、gure 2-1 of CCIR Report 624 l; at this instant, the leading edge of the line synchronization pulse coincides with the beginning of the sequence of field synchronization pulses. The lines are numbered according to their sequence in time, so that the first field comprises lines 1 to 312 as well as the
18、 first half of line 3 13, whereas the second field comprises the second half of line 313 and lines 3 i4 to 625. For 525-line systems the numbering of the lines is as follows: Line 1 of field 1 is the line starting with the fist equalizing pulse at the instant indicated by O, in Figure 2-3a of CCIR R
19、eport 624 2, line 1 of field 2 is the line starting with the second equalizing pulse at one half-line period after the instant indicated by O, in Figure 2-3b of this report. Numbering of lines in a television field 3 625-line insertion test signals The advent of colour has caused the CCIR to recomme
20、nd a comprehensive set of test signals which may be inserted on lines 17, 18, 330 and 331 for international monochrome or colour transmissions) This signal is illustrated in Figure 12) and is made up as follows: Line 17 A i0 ps white bar (Bz), a 2 T sine-squared pulse (BI), a 20 T composite pulse (F
21、) and a 5-riser staircase (Di). As an interim measure some organizations may decide to omit some of the waveforms, but in this case care must be taken not to alter the mean values appreciably. 2, A colour burst is present in the line blanking period during colour transmissions. In the case of Phase
22、attenuation line (PAL) colour transmissions the chrominance subcarrier of the insertion signals is locked at 60 from the (B-Y) axis. Recommendation N.67 (03/93) 1 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesLine 18 A multiburst (C2)
23、 preceded by a reference bar signal (CI) Line 330 A 10 ps white bar (Bz), a 2 T sine-squared pulse (BI) and a 5-riser staircase with superimposed colour subcarrier (D2). Line 331 A chrominance bar signal (GI) or a three-level chrominance signal (Gz), followed by a sub-carrier reference bar (E). 1 i
24、0.5 1.0 2.0 4.0 4.8 5.8 MHz MHz MHz MHz MHz MHz7 V 1.Or I 0.86 0.44 0.30 4 b V 1 .o 0.m 0.72 0.58 0.44 0.30 a)Line17 B2 Bi F Di 7 n /I 56 11 13 16 18 20 22 24 26 28 31 32 32 XH c) Line 330 62 B1 02 f L 56 8 11 13 15 20 22 24 26 28 303132 32 XH V 1 .o 086 0.65 O .44 b) Lime 18 Ci c2 -7 Il /L JI i 1 I
25、 5 6 8 10 12 15 18 21 24 27 303132 32 XH a) Line 331 E b4 GI v. c 567 9 11 14 17 NOTE - A detailed description of these signals is given in CCIR Recommendation 473 4. FIGURE 1hV.67 Test signal for insertion in field blanking intervals of a 625-line colour (or monochrome) television signai 3031 32 32
26、 XH TO403480-Wd01 2 Recommendation N.67 (03/93) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN*N-b7 93 4862593 0583984 501 4 525-line insertion test signals For colour the CCIR has recommended a comprehensive set of test si
27、gnals which may be inserted on lines 17 of both fields (lines 17 and 280 if numbered consecutively) for international monochrome or colour transmissions. These signals are illustrated in diagrams c) and d) of Figure 2 and are made up as follows: - Diagram c) of Figure 2: a luminance bar (reference w
28、hite level) (Bz), a 2 T sine-squared pulse (BI), a modulated 12.5 T sine-squared pulse (F) and a superimposed 5-riser staircase (D2). - Diagram d) of Figure 2: a reference bar signal (CI), a luminance pedestal, a multiburst signal superimposed on the pedestal (C2) and a superimposed 3-level chromina
29、nce signal (G). A detailed description of these signals is given in CCIR Recommendation 473 2. 5 Insertion test signals for MAC systems These insertion test signals, described in detail in CCIR Report 1096 3, are represented in Figure 3. They may be inserted in lines 312, 623, 624, 31 1, 1 and 313 o
30、f the signal. The three first signals (Nos. 1, 2 and 3) are mandatory, the others (Nos. 4,5 and 6) are optional. They are composed as follows: Line 312, signal No. 1 (mandatory), Figure 3a This is a bipolar bar signal with inverse polarity in even and odd frames. Positive and negative Blackman pulse
31、s are contained in the even frame signal only. The first part of the signal (k = 225 to 612) is provisionally set to O mV. It may be used in the future for insertion of other test signals in the time domain (e.g. - signals). sin x X Line 623, signal No. 2 (mandatory), Figure 3b It comprises a rising
32、 ramp (even frames) and a falling ramp (odd frames). Line 624, signal No. 3 (mandatory), Figure 3c The first part of the signal is already defined in the MAC-packet standards. The second part contains a complex wobbulation (see CCIR Report 1096 31). Line 311, signal No. 4 (mandatory), Figure 3d This
33、 signal consists of a bipolar pulse and bar with eight modulated pulses (1 to 8 MHz) of 500 mV amplitude. It may also be used at full amplitude (1000 mV). Line 1, signal No. 5 (optional), Figure 3e It comprises an 8-risers starcase waveform. Line 313, signal No. 6 (mandatory), Figure 3f It is compos
34、ed of eight multiburst signals (1 to 8 MHz) of 500 mV amplitude, preceded by a reference bar. It may also be used at full amplitude (1000 mV). Recommendation N.67 (03/93) 3 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN+N.b
35、1 93 4862591 O583985 448 m 4 a) Line 17hrame 1 Di c) Line 17fframe 1 DP 1 L- - O 36 44 51 60 68748086929800 b) Line 17/frame 2 Ci c2 e -+ d)Line17lframe2 I 80 I 40 2o I 01 -40 O 812 24 32 40 48 56646876 84 96100 128 XH TO403490-92/d02 (OH) (OHR) FIGURE 2N.67 Test signal for insertion in field blanki
36、ng intervals of a 525-line colour (or monochrome) television signal Recommendation N.67 (03/93) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN*N.b7 93 W 4862591 058398b 384 +0.5V W O r -0.5V O = Sample 244,590,1278 4pddiv.
37、j i Y O I -0.5V l I 0 = Sample 244, 590, 1278 4 pddiv. Odd frame T040350092/a)3 FIGURE 3aN.67 insertion test signais for MAC systems Line 3 12, signal No. 1 (mandatory) Recommendation N.67 (03/93) 5 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handli
38、ng ServicesITU-T RECMN*N-b7 93 M 4862593 0583987 210 I 1 0 = Sample 244,128 4 psdiv. I _ . L- To4035 10-9216 U Odd frame FIGURE 3WN.67 Insertim test signals for MAC systems Line 623, signal No. 2 (mandatory) 6 Recommendation N.67 (03/93) COPYRIGHT International Telecommunications Union/ITU Telecommu
39、nicationsLicensed by Information Handling ServicesITU-T RECMNaN.67 93 m 4862591 0583988 157 m - 0.5 V 0 = Sample 244,1278 4 pldiv. 1 - 0.5 V 0 = Sample 244,1278 4 Wsldiv. Odd frame FIGURE 3ciN.67 Insertion test signals for MAC system Line 624, signal No. 3 (mandatory) To4 1)3520-92/6 05 Recommendati
40、on N.67 (03/93) 7 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN*N*b7 93 = 48b259L 0583989 093 I + 0.5 V d- - 0.5 V 0 = Sample 244,590,1278 4 div. I I , I I I l I 1 ._i I I 1- T0403530-9Yd06 FIGURE 3cUN.67 Insertion test si
41、gnals for MAC system Line 3 1 1, signal No. 4 (optional) + 0.5 V -0.5 V 0 = sample 244,590,1278 4 pddiv. FIGURE 3eN.67 Insertim test signais for MAC system Line 1, signal No. 5 (optional) 8 Recommendation N.67 (03/93) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by
42、 Information Handling ServicesITU-T RECMN*N.b7 93 m 4862591 0583990 805 A Y- 1 + 0.5 V k - 0.5 V I l 0 = Sample 244,590,1278 4 pstdiv. FIGURE 3fLN.67 Insertion test signais for MAC systems Line 313, signal No. 6 (optional) 6 Measurements on insertion test signals In order to carry out measurements o
43、n an insertion test signal, stations and centres should also be equipped with a line selector which enables only the test signal line (or lines) to be displayed on the oscilloscope. Measurements which can be made with the above signals are given in Tables 1 and 2. In the cases of MAC test signals de
44、fined in 5, an automatic measuring equipment is required, since measurement methods use modem techniques of signal processing. 7 Insertion and removal of test signals in the field blanking period 7.1 International signals The appropriate international signals inserted by the originating broadcasting
45、 organization smld be transmitted to the point of destination of the television connection. Exceptionally, if the connection includes a standards or colour systems convertor which does not pass signals occurring during the field blanking period, then the signals should be monitored at the upstream v
46、ideo point nearest to the convertor and new international signals, to the appropriate standard, should be inserted at the downstream point nearest to the convertor. The test signals should be available at any video connection point in order to facilitate assessment of performance. They may also be o
47、f use in carrying out any necessary readjustment of correctors at the final destination. Recommendation N.67 (03/93) 9 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN*N.67 93 m 4862591 0583993 741 m TABLE 1m.67 625-line mono
48、chrome or colour signal (Figure i) (CCIR Recommendation 473 2) I Characteristics measured Linear distortions Insertion gain Amplitudelfrequency response Line-time waveform distortion Short-time waveform distortion - step response - pulse response ChrominanceAuminance gain inequality ChrominanceAumin
49、ance delay inequality Non-linear distonions Luminance line-time non-linearity Chrominance non-linearity Luminancekhrominance intermodulation - differential gain - differential phase ChrominanceAuminance intermodulation Waveform used B2 C2 and Cl B2 B2 B1 B2 and GI or G2 B2 and F F D1 G2 D2 D2 and E B2 and GI or G2 Line number 17 and 330 18 17 and 330 17 and 330 17 and 330 17 and 330,331 17 17 17 33 1 330 330 et 331 17,331 7.2 National signals Any test signals inserted in lines 18 to 20 (525-line systems), or 19 to 21 (625-line systems) and the corresponding li
