Reference / Paper · 1998
ITU-R Recommendation BT.470-6 — Conventional Television Systems (11/1998)
Line and field timing tables for the NTSC, PAL and SECAM systems that CRT light guns time against.
- ntsc
- pal
- secam
- line timing
- field timing
Reference / Paper · 1998
Line and field timing tables for the NTSC, PAL and SECAM systems that CRT light guns time against.
Rec. ITU-R BT.470-6 1 RECOMMENDATION ITU-R BT.470-6* CONVENTIONAL TELEVISION SYSTEMS (Question ITU-R 1/11) (1970-1974-1986-1994-1995-1997-1998) Rec. ITU-R BT.470-6 The ITU Radiocommunication Assembly, considering a) that many countries have established satisfactory monochrome television broadcasting services based on either 525-line or 625-line systems; b) that a number of countries have established (or are in the process of establishing) satisfactory colour television broadcasting services based on the NTSC, PAL or SECAM systems; c) that the use of video component signals, signals consisting of the luminance and two colour difference signals, with time compression and time division multiplexing, may offer picture quality benefits, using new types of television receivers; d) that it would add further complications to the interchange of programmes to have a greater multiplicity of systems, recommends 1 that, for a country wishing to initiate a conventional monochrome television service, a system using 525- or 625-lines as defined in Annex 1 is to be preferred; 2 that, for conventional monochrome 625-line systems, the video-frequency characteristic described in Recommendation ITU-R BT.472 is to be preferred; 3 that, for a country wishing to initiate a conventional colour television service, one of the systems defined in Annex 1 is to be preferred. NOTE 1 – Pre-1986 editions of the ex-CCIR Volumes, and in particular that of 1982, contain a complete description of system E used in France until 1984, and system A used in the United Kingdom until 1985. NOTE 2 – Pre-1997 editions of Recommendation ITU-R BT.470 contain a complete description of the SECAM IV colour television system. ANNEX 1 Characteristics of television systems The following tables, given for information purposes, contain details of a number of different television systems in use at the time of the Radiocommunication Assembly, 1995. A list of countries and geographical areas, and the television systems used, are given in Appendix 1. Information on the results of the comparative laboratory tests carried out on the various colour television systems in the period 1963-1966 by broadcasting authorities, administrations and industrial organizations, together with the main parameters of systems may be found in Reports 406 and 407, XIIth Plenary Assembly, New Delhi, 1970. All television systems listed in this Annex employ an aspect ratio of the picture display (width/height) of 4/3, a scanning sequence from left to right and from top to bottom and an interlace ratio of 2/1, resulting in a picture (frame) frequency of half the field frequency. All systems are capable of operating independently of the power supply frequency. _______________ * This Recommendation includes editorial amendments. 2 TABLE 1 Basic characteristics of video and synchronizing signals System Item Characteristics M N(1) B, B1, D1, G H I D, K K1 L Rec. ITU-R BT.472(2) 1 Number of lines per picture (frame) 525 625 625 625 625 625 625 625 625 2 Field frequency, nominal value (field/s)(3) 60 (59.94) 50 50 50 50 50 50 50 50 3 Line frequency fH and tolerance when operated non-synchronously (Hz)(3), (4) 15 750 (15 734.264 ± 0.0003%) 15 625 ± 0.15% (± 0.00014%) 15 625(5) ± 0.02% (± 0.0001%) 15 625 ± 0.02% (± 0.0001%) 15 625 ± 0.02% (± 0.0001%) 15 625 ± 0.02% (± 0.0001%) 3 a) Maximum variation rate of line frequency valid for monochrome transmission (%/s)(7), (8) 0.15 15 625(5) 15 625 15 625 (6) ± 0.02% ± 0.02% ± 0.00002% (± 0.0001%) (± 0.0001%) 0.05 0.05 0.05 0.05 0.05 0.05 4(9) Blanking level (reference level) 0 0 0 0 0 0 0 0 Peak white-level 100 100 100 100 100 100 100 100 Synchronizing level – 40 – 40 (– 43) – 43 – 43 – 43 – 43 – 43 – 43 7.5 ± 2.5(10) 7.5 ± 2.5 (0) 0 0 0 0-7 0(11) 0 (colour) 0-7 (mono.) 0 (colour) 0-7 (mono.) 133 115(12) 133(11) 115(12) 124(12) Difference between black and blanking level 133(11) Peak level including chrominance signal 120 5 Assumed gamma of display device for which pre-correction of monochrome signal is made 2.2 2.2 (2.8) 6 Nominal video bandwidth (MHz) 4.2 4.2 2.8(13) 5 5 5.5 7 Line synchronization see Table 1-1 8 Field synchronization see Table 1-2 0 +5 –0 (14) 6 6 6 5.0 or 5.5 or 6.0 Rec. ITU-R BT.470-6 Nominal and peak levels of the composite video signal (%)( (see Fig. 1) Notes to Table 1: (1) The values in brackets apply to the combination N/PAL used in Argentina. (2) Figures are given for comparison. (3) Figures in brackets are valid for colour transmission. (4) In order to take full advantage of precision offset when the interfering carrier falls in the sideband of the upper video range (greater than 2 MHz) of the wanted signal a line-frequency stability of at least 2 × 10–7 is necessary. (5) The exact value of the tolerance for line frequency when the reference of synchronism is being changed requires further study. (6) When the reference of synchronism is being changed, this may be relaxed to 15 625 ± 0.02%. (7) These values are not valid when the reference of synchronism is being changed. (8) Further study is required to define maximum variation rate of line frequency valid for colour transmission. In the United Kingdom and Japan this is 0.1 Hz/s. (9) It is also customary to define certain signal levels in 625-line systems, as follows: = 0 = 30 = 100 For this scale, the peak level including chrominance signal for system D, K/SECAM equals 110.7. According to common studio operating practices, peak white-level = 100 corresponds to 1.0 V measured across a matched 75 Ω termination. (10) +10 In Japan values 0 – 0 are used. (11) Value applies to PAL signals. (12) Values apply to SECAM signals. For programme exchange the value is 115. (13) Assumed value for overall gamma approximately 1.2. The gamma of the picture tube is defined as the slope of the curve giving the logarithm of the luminance reproduced as a function of the logarithm of the video signal voltage when the brightness control of the receiver is set so as to make this curve as straight as possible in a luminance range corresponding to a contrast of at least 1/40. (14) In Recommendation ITU-R BT.472, a gamma value for the picture signal is given as approximately 0.4. Rec. ITU-R BT.470-6 Synchronizing level Blanking level Peak white-level 3 4 Rec. ITU-R BT.470-6 FIGURE 1 Levels in the composite signal and details of line-synchronizing signals OH a b g c 7 h d 2 5 1 4 3 f e f a) NTSC and PAL systems OH a b i c d 7 2 6 1 4 3 e f f b) SECAM system 1 Blanking level 2 Peak white-level 3 Synchronizing level 4 Difference between black and blanking levels 5 Peak-to-peak value of burst 6 Peak-to-peak value of colour sub-carrier 7 Peak level including chrominance signal 0470-01 Rec. ITU-R BT.470-6 5 TABLE 1-1 Details of line synchronizing signals (see Fig. 1) Durations (measured between half-amplitude points on the appropriate edges) for various systems Symbol Characteristics M(1) N(2) B, B1, G, H, I, D, D1, K, K1, L (see also Rec. ITU-R BT.472) H Nominal line period (µs) 63.492 (63.5555) 64 64(3) a Line-blanking interval (µs) 10.2 to 11.4(4) (10.9 ± 0.2) 10.24 to 11.52 (12 ± 0.3) +0.0 12 −0.3 µs(5) b Interval between time datum (OH) and back edge of line-blanking pulse (µs) 8.9 to 10.3 (9.2 to 10.3) 8.96 to 10.24 (10.5) 10.5(6) c Front porch (µs) 1.27 to 2.54 (1.27 to 2.22) 1.28 to 2.56 (1.5 ± 0.3) +0.3 1.5 −0.0 µs(5) d Synchronizing pulse (µs) 4.19 to 5.71(4) (4.7 ± 0.1) 4.22 to 5.76 (4.7 ± 0.2) 4.7 ± 0.2 e Build-up time (10 to 90%) of the edges of the lineblanking pulse (µs) ≤ 0.64 ≤ 0.48 ≤ 0.64 (0.3 ± 0.1) 0.3 ± 0.1 f Build-up time (10 to 90%) of the edges of the linesynchronizing pulses (µs) ≤ 0.25 ≤ 0.25 (0.2 ± 0.1) 0.2 ± 0.1(7) (1) Values in brackets apply to M/NTSC. (2) The values in brackets apply to the combination N/PAL used in Argentina. (3) In France, and some countries of the former OIRT, the tolerance for the instantaneous line period value is ± 0.032 µs. (4) In Japan, the values in brackets apply to studio facilities. (5) The tolerances for Symbols a and c are the preferred values that take into account the need to reduce the possibilities of data loss in 625-line countries using Teletext System B as specified in Annex 1 to Recommendation ITU-R BT.653. (6) Average calculated value, for information. (7) For system I, the values are 0.25 ± 0.05. 6 Rec. ITU-R BT.470-6 FIGURE 2 Details of field-synchronizing waveforms FIGURES 2-1 Diagrams applicable to all systems except M j l n m OV First field Second field See Fig. 2-1c FIGURE 2-1a – Signal at the beginning of each first field j l n m OV First field See Fig. 2-1c Second field FIGURE 2-1b – Signal at the beginning of each second field Note 1 – indicates an unbroken sequence of edges of line-synchronizing pulses throughout the field-blanking period. Note 2 – At the beginning of each first field, the edge of the field-synchronizing pulse, OV, coincides with the edge of a line-synchronizing pulse if l is an odd number of half-line periods as shown. Note 3 – At the beginning of each second field, the edge of the field-synchronizing pulse, OV, falls midway between the edges of two line-synchronizing pulses if l is an odd number of half-line periods as shown. Note 4 – The dominant field is defined as that field of the video waveform at which a change of picture material should occur. The change of picture information should occur at the beginning of the first field. s s s s Blanking level Sync level q p H 2 r H 2 (The durations are measured between the half-amplitude points on the appropriate edges) FIGURE 2-1c – Details of equalizing and synchronizing pulses FIGURE 2-1/BT.470-1...[D02] = PAGE PLAINE 0470-021 Rec. ITU-R BT.470-6 7 FIGURE 2 Details of field-synchronizing waveforms FIGURES 2-2 Diagrams applicable to system M j l n m See Fig. 2-2c OE1 Second field First field FIGURE 2-2a – Signal at the beginning of each first field j l n m See Fig. 2-2c OE2 First field Second field FIGURE 2-2b – Signal at beginning of each second field Note 1 – indicates an unbroken sequence of edges of line-synchronizing pulses throughout the field-blanking period. Note 2 – Field-one line numbers start with the first equalizing pulse in Field 1, designated OE1 in Fig. 2-2a. Note 3 – Field-two line numbers start with the second equalizing pulse in Field 2, one-half-line period after OE2 in Fig. 2-2b. s s s s Blanking level Sync level q p H 2 r H 2 FIGURE 2-2c – Details of equalizing and synchronizing pulses 0470-022 8 Rec. ITU-R BT.470-6 TABLE 1-2 Details of field synchronizing signals (see Fig. 2) Duration (measured between half-amplitude points on the appropriate edges) for various systems Symbol Characteristics M N(1) B, B1, G, H, I, D, D1, K, K1, L (see also Rec. ITU-R BT.472) ν Field period (ms) 16.667(2) (16.6833) 20 20 j Field-blanking interval (for H and a, see Table 1-1) (19 to 21) H + a(3) (19 to 25) H + a (25 H + a) 25 H + a j′(4) Build-up time (10 to 90%) of the edges of fieldblanking pulses (µs) ≤ 6.35 ≤ 6.35 (0.3 ± 0.1) 0.3 ± 0.1 k(4) Interval between front edge of field-blanking interval and front edge of first equalizing pulse (µs) (1.5 ± 0.1) l Duration of first sequence of equalizing pulses 3H 3H (2.5 H) 2.5 H m Duration of sequence of synchronizing pulses 3H 3H (2.5 H) 2.5 H n Duration of second sequence of equalizing pulses 3H 3H (2.5 H) 2.5 H p Duration of equalizing pulse (µs) (2.3 ± 0.1)(6) 2.30 to 2.56 (2.35 ± 0.1) (2.35 ± 0.1) q Duration of field-synchronizing pulse (µs) 27.1 (nominal value) 26.52 to 28.16 (27.3) 27.3(7) (nominal value) r Interval between field-synchronizing pulse (µs) (4.7 ± 0.1) 3.84 to 5.63 (4.7 ± 0.2) (4.7 ± 0.2)(8) s Build-up time (10 to 90%) of synchronizing and equalizing pulses (µs) ≤ 0.25 ≤ 0.25 (0.2 ± 0.1) (0.2 ± 0.1)(9) 3 ± 2(5) (systems B, D, G, K/SECAM, K1 and L only; no ref. in Rec. ITU-R BT.472) (1) The values in brackets apply to the combination N/PAL used in Argentina. (2) The value in brackets applies to the M/NTSC system. (3) The value 0.07 ν – 0 (4) Not indicated in the diagram. (5) This value is to be specified more precisely at a later date. (6) The following specification is also applied in Japan: an equalizing pulse has 0.45 to 0.5 times the area of a line-synchronizing pulse. (7) For system I: 27.3 ± 0.1. (8) For system I: 4.7 ± 0.1. (9) For system I: 0.25 ± 0.05. +0.012 ν is used in Japan where ν is the field period. TABLE 2 Characteristics of video signal for colour television Item Characteristics 2.1 Assumed chromaticity coordinates (CIE, 1931) for primary colours of receiver Chromaticity coordinates for equal primary signals 2.2 M/NTSC Colour television system I/PAL B, B1, D, D1, G, H, K, N/PAL M/PAL Red Green Blue x 0.67 0.21 0.14 y 0.33 0.71 0.08 N/PAL(1) B, D, G, H, K, K1, L/SECAM x 0.64 0.29 0.15 Red Green Blue y 0.33 0.60 0.06 (2) Illuminant D65 Illuminant C x = 0.310 y = 0.316 x = 0.313 y = 0.329 (3) (2) ′ = E′B E′R = EG 2.4 Assumed gamma value of the receiver for which the primary signals are pre-corrected(4) Luminance signal 2.2 2.8 ′ + 0.114 E′B EY′ = 0.299 E ′R + 0.587 EG (5) ′ and E ′B are gamma – pre-corrected primary signals E′R , EG 2.5 Chrominance signals (colour difference) Rec. ITU-R BT.470-6 2.3 E′I = – 0.27 ( E ′B – EY′ ) + + 0.74 ( E′R – EY′ ) ′ = 0.41 ( E ′B – EY′ ) + EQ (6) EU′ = 0.493 ( E′B – EY′ ) D′R = – 1.902 ( E′R – EY′ ) EV′ = 0.877 ( E ′R – EY′ ) D′B = 1.505 ( E′B – EY′ ) + 0.48 ( E ′R – EY′ ) 2.6 Attenuation of colour difference signals dB MHz E′I < 3 at 1.3 ≥ 20 at 3.6 < 2 at 0.4 E′Q < 6 at 0.5 ≥ 6 at 0.6 dB MHz dB MHz dB MHz dB MHz EU′ < 2 at 1.3 EU′ < 3 at 1.3 D′R ≤ 3 at 1.3 EU′ < 3 at 1.3 EV′ > 20 at 3.6 EV′ > 20 at 4 D′B ≥ 30 at 3.5 EV′ > 20 at 3.6 Low frequency pre-correction not taken into account(7) 9 10 TABLE 2 (continued) Item Characteristics 2.7 Low frequency precorrection of colour difference signals M/NTSC M/PAL Colour television system B, B1, D, D1, G, H, K, I/PAL N/PAL B, D, G, H, K, K1, L/SECAM For sinusoidal signals: D′R* = A BF ( f ) D′R D′B* = A BF ( f ) D′B ABF ( f ) = 1 + j ( f / f1 ) 1 + j ( f / 3 f1 ) 2.9 < 0.05 Excluding pre-correction for receiver response Time-coincidence error between luminance and chrominance signals (µs) Equation of composite colour signal E M = E ′Y + E M = E ′Y + E ′U sin 2 n f ′ + E ′V cos 2 n f ′ sc sc ′ + ∆f OR f 0′ D′R* dt ) ( f OR ′ sin ( 2 n f ′ + 33°) + + EQ sc + E′I cos ( 2 n f ′ + 33°) sc E M = E′Y + G cos 2 π where: or E M = EY′ + G cos 2 π ′ + ∆f OB f 0′ D′B* dt ) ( f OB where: E′Y , see item 2.4 E′Y , see item 2.4 E′U and E′V , see item 2.5 alternately from line to line where: ′ and E′I , see item 2.5 EQ f sc , see item 2.11 E′Y , see item 2.4 f sc , see item 2.11 The sign of the E′Y component is the same as that of the sub-carrier burst (changing for each line) (see item 2.16 and Fig. 4b) (See also Fig. 4a) fOR and fOB , see item 2.11 ∆fOR and ∆fOB , see item 2.12 D′R* and D′B*, see item 2.7 G, see item 2.13 See Notes at the end of Table 2. Rec. ITU-R BT.470-6 ƒ : signal frequency (kHz) ƒ1 = 85 kHz (See Fig. 6 for the amplitude response)(8) 2.8 N/PAL(1) TABLE 2 (continued) Colour television system Item Characteristics 2.10 Type of chrominance sub-carrier modulation Suppressed-carrier amplitude-modulation of two sub-carriers in quadrature 2.11 Chrominance subcarrier frequency 3 579 545 ± 10 Nominal value and tolerance (Hz) b) Relationship between chrominance sub- carrier frequency fsc and line frequency fH M/PAL B, B1, D, D1, G, H, K, N/PAL 3 579 611.49 ± 10 4 433 618.75 ± 5 I/PAL Frequency deviation of chrominance subcarrier (frequency modulation of subcarrier) (kHz) N/PAL(1) Frequency modulation 4 433 618.75 ± 1(9), (10) fOR = 4 406 250 ± 2 000 3 582 056.25 ± 5 fOB = 4 250 000 ± 2 000 (11) f sc = 455 2 fH f sc = 909 4 æ 1 135 1 ö + ÷ fH 625 ø è 4 f sc = ç fH Unmodulated sub-carrier at beginning of line 282 fH for fOR æ 917 1 ö + ÷ fH è 4 625ø fsc = ç 272 fH for fOB(12) Bandwidth of chrominance sidebands (quadrature modulation of subcarrier) (kHz) or B, D, G, H, K, K1, L/SECAM f sc + 620 – 1 300 f sc + 600 – 1 300 f sc + 570 – 1 300 (13) f sc Nominal deviation D′* = 1(14) Maximum deviation ∆ fOR 280 ± 9 +350 ± 18 (15) (± 14) (± 35) + 1 066 –506 ± 25 – 1 300 (± 50) ∆ fOB 230 ± 7 +506 ± 25 (15) (± 11.5) (± 50) f sc Rec. ITU-R BT.470-6 2.12 a) M/NTSC + 620 – 1 300 –350 ± 18 (± 35) See Notes at the end of Table 2. 11 12 TABLE 2 (continued) Colour television system Item Characteristics M/NTSC 2.13 Amplitude of chrominance sub-carrier G= 2 M/PAL 2 ′ E ′I + EQ B, B1, D, D1, G, H, K, N/PAL G= 2 I/PAL 2 EU′ + EV′ B, D, G, H, K, K1, L/SECAM G = M0 (16), (17) (16) N/PAL(1) 1 + j 16 F 1 + j 1.26 F where the peak-to-peak amplitude, 2M0 is 23 ± 2.5% of the luminance amplitude (between blanking level and peak-white) f f0 – f0 Rec. ITU-R BT.470-6 and F = f where f0 = 4 286 kHz and f is the instantaneous sub-carrier frequency. The deviation of frequency, f0, from its nominal value due to misalignment of the circuits concerned should not exceed ± 20 kHz.(See Fig. 7 for the amplitude response) 2.14 Synchronization of chrominance subcarrier Sub-carrier burst on blanking back porch Sub-carrier burst on blanking back porch g) Start of subcarrier burst (µs) (see Fig. 1a) 4.71 to 5.71 (5.3 nominal) at least 0.38 µs after the trailing edge of line synchroni-zation signal 5.8 ± 0.1 after epoch OH 5.6 ± 0.1 after epoch OH h) Duration of sub-carrier burst (µs) (see Fig. 1a) 2.23 to 3.11 (9 ± 1 cycles) 2.52 ± 0.28 (9 ± 1 cycles) 2.25 ± 0.23 (10 ± 1 cycles) See Notes at the end of Table 2. (18) 2.51 ± 0.28 (9 ± 1 cycles) TABLE 2 (continued) Colour television system Characteristics M/NTSC 2.15 Peak-to-peak value of chrominance subcarrier burst (see Fig. 1a)(19) 4/10 of difference between blanking level and peak white-level ± 10% Phase of chrominance subcarrier burst 180° relative to E′B – EY′ axis (see Fig. 4a). In the NTSC sequence of four colour fields, field 1 is identified in accordance with Note(20) (see also Fig. 5c) 2.16 (see Fig. 1a) M/PAL Blanking of chrominance subcarrier Following each equalizing pulse and also during the broad synchronizing pulses in the field-blanking interval I/PAL B, D, G, H, K, K1, L/SECAM N/PAL(1) 3/7 of difference between blanking level and peak white-level ± 10% For systems D and I the tolerance is ± 3% (16), (17) (16) 135° relative to EU′ axis with the following sign (see Fig. 4b) Field No.(21) Line 1 2 3 4 5 6 7 8 Burst blanking sequence (see Figs. 5a and 5b) Even Odd 2.17 B, B1, D, D1, G, H, K, N/PAL I II III IV I II III IV – + – + + – + – – + – + + – + – 11 lines of fieldblanking interval: 260 to 270 522 to 7 259 to 269 233 to 8 (see Fig. 5b) 9 lines of the field-blanking interval: lines a) 311 to 319 inclusive 623 to 6 inclusive 310 to 318 inclusive 622 to 5 inclusive From leading edge of line-blanking signal up to i = 5.6 ± 0.2 (µs) after epoch OH, Rec. ITU-R BT.470-6 Item i.e. during c + i (see Fig. 1b)(22) (see Fig. 5a) b) During field-blanking interval, excluding frame identification signals, or, in countries where this is possible, during the whole of the fieldblanking interval (see item 2.18) See Notes at the end of Table 2. 13 14 TABLE 2 (continued) Colour television system Characteristics M/NTSC 2.18 Synchronization of chrominance sub-carrier switching during line blanking See item 2.16. For signals used in programme integration, the tolerance on the coincidence between the reference subcarrier and the horizontal synchronizing pulses in nominally 0 ± 40° of the reference subcarrier M/PAL B, B1, D, D1, G, H, K, N/PAL I/PAL B, D, G, H, K, K1, L/SECAM By EV′ chrominance component of sub-carrier burst (see item 2.16) In the SECAM system, one of two colour synchronization methods can be chosen: – Line identification: by chrominance sub-carrier reference signals on the line-blanking back porch(23) – By identification signals occupying 9 lines of field-blanking period: a) line 7 to 15 in 1st and 3rd field b) line 320 to 328 in 2nd and 4th field (see Fig. 9)(24) Shape of video signals corresponding to identification signals: For lines D′R – Trapezoid with linear variation from beginning of line on 15 ± 5 µs from 0 up to level +1.25 and then constant at the level +1.25 ± 0.06 (± 0.13) (see Fig. 8) See Notes at the end of Table 2. N/PAL(1) Rec. ITU-R BT.470-6 Item TABLE 2 (continued) Colour television system Item Characteristics M/NTSC M/PAL B, B1, D, D1, G, H, K, N/PAL I/PAL B, D, G, H, K, K1, L/SECAM N/PAL(1) For lines D′B – Trapezoid with linear variation from the beginning of the line on 18 ± 6 µs (20 ± 10 µs) from 0 down to level –1.52 and then constant at the level −1.52 ± 0.07 (± 0.15) (see Fig. 8)(15) Peak-to-peak amplitude of identification signals: 500 ± 50 mV For lines D′R : 500 + 40 mV – 40 mV if amplitude of luminance signal (between blanking level and peak white) equals 700 mV Rec. ITU-R BT.470-6 For lines D′B : Maximum deviation during transmission of identification signals (kHz): For lines D′R : + 350 ± 18 (± 35) For lines D′B : – 350 ± 18 (± 35) (15) See Notes at the end of Table 2. 15 16 fsc ± 1 300 kHz is adopted in the People’s Republic of China. The unity value represents the amplitude of the luminance signal between the blanking level and the peak white-level. Provisionally, the tolerances may be extended up to the values given brackets. During transmission of a monochrome programme of significant duration, in order to ensure satisfactory operation of colour-killers in receivers, all signals having the same nominal frequency as the colour sub-carrier that appears in the line-blanking interval, should be attenuated by at least 35 dB below the peak-to-peak value of the burst given in item 2.15, column 3 of Table 2, and shown as item 5 in Fig. 1. The value given in Note (16) is accepted on a tentative basis. Transmitter pre-correction for receiver group delay is not included. For the use of automatic gain control circuits, it is important that the burst amplitude should maintain the correct ratio with the chrominance signal amplitude. Field 1 of the sequence of four fields in the NTSC video signal is defined by a whole line between the first equalizing pulse and the preceding horizontal synchronizing pulse and a negative-going zero-crossing of the reference sub-carrier nominally at the 50% point of the first equalizing pulse. The zero-crossing of the reference sub-carrier shall be nominally coincident with the 50% point of the leading edges of all horizontal synchronizing pulses for programme integration at the studio. Field 1 of the sequence of eight colour fields is defined as that field, where the phase ϕ EU′ of the extrapolated E′U component (see item 2.5 of Table 2) of the video burst at the hall amplitude point of the leading edge of the line synchronizing pulse of line 1 is in the range – 90° ≤ ϕ E′U < 90° . The value of the tolerance will be defined more precisely later. The line identification method is preferable, because it will enable agreements to be reached subsequently on the suppression of frame identification signals in international programme exchanges. In the absence of such agreements, signals meeting the SECAM standard are regarded as comprising such identification signals. In France, a decree of 14 March 1978 specified that colour TV receivers placed on sale on or after 1 December 1979 must use the line identification method of decoding. In France and Ukraine, studies are taking place with a view to reducing the number of lines used for field colour identification signals. The order in which the identification signals D * and D* appear on the four fields of R B a complete cycle given in Fig. 9 is in conformity with Recommendation ITU-R BR.469. Rec. ITU-R BT.470-6 (13) Notes to Table 2: (1) These values apply to the combination N/PAL used in Argentina. Only those values are (14) given in this column which are different from the values given in the column B, G, H, (15) N/PAL. (2) For SECAM systems and for existing sets, it is provisionally allowed to use the following (16) chromaticity coordinates for the primary colours and white: x y Red 0.67 0.33 Green 0.21 0.71 (17) Blue 0.14 0.08 (18) White 0.310 0.316 (C-white) (19) (3) In Japan, the chromaticity of studio monitors is adjusted to a D-white at 9 300 K. (4) The primary signals are pre-corrected so that the optimum quality is obtained with a display (20) having the indicated value of gamma. (5) In certain countries using the SECAM systems and in Japan it is also permitted to obtain the luminance signal as a direct output from an independent photo-electric analyser instead of from the primary signals. (6) For the SECAM system, it is allowable to apply a correction to reduce interference distortions between the luminance and chrominance signals by an attenuation of the (21) luminance signal components as a function of the amplitude of the luminance components in the chrominance band. (7) This value will be defined more precisely later. (8) The maximum deviations from the nominal shape of the curve (see Fig. 6) should not (22) exceed ± 0.5 dB in the frequency range from 0.1 to 0.5 MHz and ± 1.0 dB in the frequency (23) range from 0.5 to 1.3 MHz. (9) When the signal originates from a portable or overseas source the tolerance on the frequency may be relaxed to ± 5 Hz. Maximum rate of variation of fsc = 0.1 Hz/s. (10) This tolerance may not be maintained during such operational procedures as “genlock”. (11) A reduction of the tolerance is desirable. (12) The initial phase of the sub-carrier undergoes in each line a variation defined by the following rule: (24) From frame to frame: by 0°: 180°: 0°: 180°: and so on, and also from line to line in either one of the following two patterns: 0°: 0°: 180°: 0°: 0°: 180°: and so on, or 0°: 0°: 0°: 180°: 180°: 180°: and so on. TABLE 3 Characteristics of the radiated signals (monochrome and colour) Item Characteristics M N(1) B, B1, G H I D, D1, K K1 L B:7 B1, G:8 8 8 8 8 8 + 5.5 ± 0.001 + 5.5 + 5.9996 ± 0.0005(7) + 6.5 ± 0.001(6) + 6.5(8) + 6.5(8) Frequency spacing (see Fig. 10) 1 Nominal radio-frequency channel bandwidth (MHz) 6 6 2 Sound carrier relative to vision carrier (MHz) + 4.5(2) + 4.5 (3), (4), (5), (6) Nearest edge of channel relative to vision carrier (MHz) –1.25 –1.25 –1.25 –1.25 –1.25 –1.25 –1.25 –1.25 4 Nominal width of main sideband (MHz) 4.2 4.2 5 5 5.5 D, K: 6 D1: 5 6 6(8) 5 Nominal width of vestigial sideband (MHz) 0.75 0.75 0.75 1.25 1.25(32) 0.75 1.25 1.25(9) 6 Minimum attenuation of vestigial sideband (dB at MHz)(10) 20 (–1.25) 42 (–3.58) 20 (–1.25) 42 (–3.5) 20 (–1.25) 20 (–3.0) 30 (– 4.43) 20 (–1.75) 20 (–3.0) 20 (–3.0) 30 (– 4.43) 20 (–1.25) 30 (– 4.33 ± 0.1) 15 (–2.7) 30 (– 4.3) (12), (13) 20 (–2.7) 30 (– 4.3) ref.: 0 (+ 0.8) (11) 7 Type and polarity of vision modulations (32) (9) ref.: 0 (+ 0.8) C3F neg. C3F neg. C3F neg. C3F neg. C3F neg. C3F neg. C3F neg. C3F pos. 100 100 100 100 100 100 100 < 6(8) Blanking level 72.5 to 77.5 72.5 to 77.5 (75 ± 2.5) 75 ± 2.5 72.5 to 77.5 76 ± 2 75 ± 2.5 75 ± 2.5 30 ± 2 Difference between black level and blanking level 2.88 to 6.75 2.88 to 6.75 0 to 2 (nominal) 0 to 7 0 (nominal) 0 to 4.5 0 to 4.5 0 to 4.5 10 to 15 10 to 15 (10 to 12.5) 10 to 15 10 to 12.5 20 ± 2 10 to 15 10 to 12.5 100 (≈ 110) (20) F3E F3E F3E F3E F3E F3E F3E A3E Rec. ITU-R BT.470-6 3 Levels in the radiated signal (% of peak carrier) Synchronizing level 8 Peak white-level 9 Type of sound modulation (15) (14) (14), (17) (16) (18), (19) See Notes at the end of Table 3. 17 18 TABLE 3 (continued) Item Characteristics M N(1) B, B1, G H I D, D1, K K1 10 Frequency deviation (kHz) ± 25 ± 25 ± 50 ± 50 ± 50 ± 50 ± 50 11 Pre-emphasis for modulation (µs) 75 75 50 50 50 50 50 12 Ratio of effective radiated powers of vision and (primary) sound(21) 10/1 to 5/1 10/1 to 5/1 20/1 to 10/1 5/1 to 10/1 5/1 10/1(24) 20/1(7), (25) 10/1 to 5/1 10/1 13 Pre-correction for receiver group-delay characteristics at medium video frequencies (ns) (see also Fig. 3) 0 æ 1 MHz 0 ± 100ö ç ÷ ç 1 MHz 0 ± 100÷ ç ÷ è 1 MHz 0 ± 60 ø (28) (29, 31) 14 Pre-correction for receiver group-delay characteristics at colour sub-carrier frequency (ns) (see also Fig. 3) –170 (nominal) + 60 ö æç ÷ è − 170− 40 ø –170 (nominal) (30, 31) (22) (3), (6), (23) (6), (26) L 10/1 10/1 to 40/1 (8), (27) (1) The values in brackets apply to the combination N/PAL used in Argentina. (2) In Japan, the values + 4.5 ± 0.001 are used. (3) In the Federal Republic of Germany, Austria, Italy, the Netherlands, Slovakia and Switzerland a system of two sound carriers is used, the frequency of the second carrier being 242.1875 kHz above the frequency of the first sound carrier. The ratio between vision/sound e.r.p. for this second carrier is 100/1. For further information on this system see Recommendation ITU-R BS.707. For stereophonic sound transmissions a similar system is used in Australia with vision/sound power ratios being 20/1 and 100/1 for the first and second sound carriers respectively. (4) New Zealand uses a sound carrier displaced 5.4996 ± 0.0005 MHz from the vision carrier. (5) The sound carrier for single carrier sound transmissions in Australia may be displaced 5.5 ± 0.005 MHz from the vision carrier. (6) In Denmark, Finland, New Zealand, Sweden and Spain a system of two sound carriers is used. In Iceland, Norway and Poland the same system is being introduced. The second carrier is 5.85 MHz above the vision carrier and is DQPSK modulated with 728 kbit/s sound and data multiplex. The ratios between vision/sound power are 20/1 and 100/1 for the first and second carrier respectively. For further information, see Recommendation ITU-R BS.707. (7) In the United Kingdom, a system of two sound carriers is used. The second sound carrier is 6.552 MHz above the vision carrier and is DQPSK modulated with a 728 kbit/s sound and data multiplex able to carry two sound channels. The ratio between vision and sound e.r.p. for the second carrier is 100/1. (8) In France, a digital carrier 5.85 MHz away from the vision carrier may be used in addition to the main sound carrier. It is modulated in differentially encoded QPSK with a 728 kbit/s sound and data multiplexer capable of carrying two sound channels. The nominal width of the main sideband is limited to 5.1 MHz. With the L standard, the depth of video modulation in the radiated signal is reduced to leave a residual radiated carrier level of 5 ± 2%. For further information, see Recommendation ITU-R BS.707. Rec. ITU-R BT.470-6 (28) Notes to Table 3 (continued): (9) In France a vestigial sideband of 0.75 MHz is optionally used. In such cases, typical values to be used for minimum attenuation of vestigial sideband are 15 (–1.25) and 30 (–4.3) in dB at MHz. (10) In some cases, low-power transmitters are operated without vestigial-sideband filter. (11) For B/SECAM and G/SECAM: 30 dB at – 4.33 MHz, within the limits of ± 0.1 MHz. (12) In some countries, members of the former OIRT, additional specifications are in use: a) not less than 40 dB at – 4.286 MHz ± 0.5 MHz, b) 0 dB from – 0.75 MHz to + 6.0 MHz, c) not less than 20 dB at ± 6.375 MHz and higher. Reference: 0 dB at +1.5 MHz. In the People’s Republic of China, the attenuation value at the point (– 4.33 ± 0.1) has not yet been determined. (14) Australia uses the nominal modulation levels specified for system I. (15) In Japan, the values of 0 to 6.75 have been adopted. (16) In the People’s Republic of China, the values 0 to 5 have been adopted. (17) Italy is considering the possibility of controlling the peak white-level after weighting the video frequency signal by a low-pass filter, so as to take account only of those spectrum components of the signal that are likely to produce inter-carrier noise in certain receivers when the nominal level is exceeded. Studies should be continued with a view to optimizing the response of the weighting filter to be used. (18) The former USSR has adopted the value 15 ± 2%. (19) A new parameter “white level with sub-carrier” should be specified at a later date. For that parameter, the former USSR has adopted the value of 7 ± 2%. (20) The peak white-level refers to a transmission without colour sub-carrier. The figure in brackets corresponds to the peak value of the transmitted signal, taking into account the colour sub-carrier of the respective colour television system. (21) The values to be considered are: Rec. ITU-R BT.470-6 (13) – the r.m.s. value of the carrier at the peak of the modulation envelope for the vision signal. For system L, only the luminance signal is to be considered. (See Note(16) above); – the r.m.s. value of the unmodulated carrier for amplitude-modulated and frequency-modulated sound transmissions. (22) In Japan, a ratio of 1/0.15 to 1/0.35 is used. In the United States, the sound carrier e.r.p. is not to exceed 22% of the peak authorized vision e.r.p. (23) Recent studies in India confirm the suitability of a 20/1 ratio of effective radiated powers of vision and sound. This ratio still enables the introduction of a second sound carrier. (24) The ratio 10/1 is used in the Republic of South Africa. 19 20 Notes to Table 3 (continued): The ratio 20:1 is used in the United Kingdom. (26) In the People’s Republic of China, the value 10/1 has been adopted. (27) In France, the ratios 10/1 and 40/1 are used. (28) In the Federal Republic of Germany and the Netherlands the correction for receiver group-delay characteristics is made according to curve B in Fig. 3a). Tolerances are shown in the table under Fig. 3a). Spain uses curve A. Some former OIRT countries using the B/SECAM and G/SECAM systems use a nominal pre-correction of 90 ns at medium video frequencies. In Sweden, the precorrection is 0 ± 40 ns up to 3.6 MHz. For 4.43 MHz, the correction is –170 ± 20 ns and for 5 MHz it is –350 ± 80 ns. In New Zealand the pre-correction increases linearly from 0 ± 20 ns at 0 MHz to 60 ± 50 ns at 2.25 MHz, follows curve A of Fig. 3a) from 2.25 MHz to 4.43 MHz and then decreases linearly to –300 ± 75 ns at 5 MHz. In Australia, the nominal pre-correction follows curve A up to 2.5 MHz, then decreases to 0 ns at 3.5 MHz, –170 ns at 4.43 MHz and –280 ns at 5 MHz. Based on studies on receivers in India, the receiver group delay pre-equalization proposed to be adopted in India at 1 MHz, 2 MHz, 3 MHz, 4.43 MHz and 4.8 MHz is +125 ns, +150 ns, +142 ns, –75 ns and –200 ns respectively. In Denmark, the precorrections at 0, 0.25, 1.0, 2.0, 3.0, 3.8, 4.43 and 4.8 MHz are 0, +5, +53, +75, +75, 0, –170 and 400 ns. (29) Not yet determined. The former Czechoslovak Socialist Republic proposed +90 ns (nominal value). (30) Not yet determined. The former Czechoslovak Socialist Republic proposed +25 ns (nominal value). (31) In Poland no group-delay precorrection is used. (32) In the United Kingdom, for PAL transmissions in the upper-adjacent channel to a DVB-T service, the nominal width of the vestigial sideband is proposed to be 0.75 MHz, with minimum attenuations of the vestigial sideband of 20 (–1.25), 45 (–1.45) in dB at MHz. Such transmission will be referred to as System II. Rec. ITU-R BT.470-6 (25) Rec. ITU-R BT.470-6 21 FIGURE 3 Curve of pre-correction for receiver group-delay characteristics 120 80 B 40 A 0 – 40 Group delay (ns) – 80 – 120 – 160 – 170 – 200 A – 240 – 280 B – 320 – 360 – 400 – 440 0 1 2 3 4 5 0 1 2 4.43 3 4 5 3.58 Frequency (MHz) a) B/PAL and G/PAL systems (See Table 3 (28) ) b) M/PAL and M/NTSC systems Nominal values and tolerances (ns) Frequency (MHz) Curve A Curve B 0.25 1.00 2.00 3.00 3.75 4.43 4.80 + 30 ± 50 + 60 ± 50 + 60 ± 50 0 ± 50 – 170 ± 35 – 260 ± 75 +5± 0 + 53 ± 40 + 90 ± 40 + 75 ± 40 0 ± 40 – 170 ± 40 – 400 ± 90 0470-03 22 Rec. ITU-R BT.470-6 FIGURE 4 Chrominance axes and phase of the burst 0.877 (E′R – E′Y) E′I E′Q 90° B 33° 0.493 (E′Β – E′Y) B: phase of the burst a) NTSC system A 0.877 (E′R – E′Y) = E′V + 135° 0.493 (E′Β – E′Y) = E′U – 135° A: phase of the burst in odd lines of the first, second, fifth and sixth fields and in even lines of the third, fourth, seventh and eighth fields B: phase of the burst in even lines of the first, second, fifth and sixth fields and in odd lines of the third, fourth, seventh and eighth fields B b) PAL system FIGURE 4/BT.470-1...[D05] = 18 cm 0470-04 Rec. ITU-R BT.470-6 23 FIGURE 5a Burst-blanking sequence in the B, B1, D, D1, G, H, K and I/PAL systems OV A B IV 308 309 310 311 312 313 314 315 316 317 318 319 320 A B I 621 622 623 624 625 1 2 3 4 5 6 7 A B II 308 309 310 311 312 313 314 315 316 317 318 319 A B 320 III 621 622 623 624 625 1 2 3 4 5 6 7 I II C III IV OV: field-synchronizing datum I, II, III, IV: first and fifth, second and sixth, third and seventh, fourth and eighth fields (see item 2.16 of Table 2) A: B: phase of burst; nominal value +135° C: burst-blanking intervals FIGURE 5a/BT.470-1...[D06] = 16 cm phase of burst; nominal value –135° 0470-05a 24 Rec. ITU-R BT.470-6 FIGURE 5b Burst-blanking sequence in M/PAL system OV A B I 519 520 521 522 523 524 525 1 2 3 4 5 6 7 8 9 A 10 B II 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 A B 272 III 519 520 521 522 523 524 525 1 2 3 4 5 6 7 8 A 9 10 B IV 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 I II C III IV OV: field-synchronizing datum I, II, III, IV: first and fifth, second and sixth, third and seventh, fourth and eighth fields (see item 2.16 of Table 2) A: phase of burst; nominal value +135° B: C: phase of burst; nominal value –135° FIGURE 5b/BT.470-1...[D07] = 16 cm burst-blanking intervals 0470-05b Rec. ITU-R BT.470-6 25 FIGURE 5c Burst-blanking sequence in M/NTSC system Colour field I Field-blanking period 19 H minimum Time 1.5 ± 0.1 µs H T1 3H 1 2 3H 3 4 3H 5 6 7 8 9 10 18 19 Colour frame A (fields I and II) 1050 20 H Start of field I H sync interval 0.5 H H Pre-equalizing pulse interval Vertical sync pulse interval Reference sub-carrier phase, colour field I Line vertical interval 263 0.5 H Post-equalizing pulse interval Colour field II Field-blanking period T1 + V 262 H 264 265 266 267 268 269 270 271 272 273 281 282 (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (18) (19) H H Start of field II Reference sub-carrier phase, colour field II Colour field III Field-blanking period T1 + 2 V Colour frame B (fields III and IV) 525 526 527 528 529 530 531 532 533 534 535 543 544 (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (18) (19) 545 Start of field III Reference sub-carrier phase, colour field III Colour field IV Field-blanking period T1 + 3 V 787 788 789 790 791 792 793 794 795 796 797 798 806 807 (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (18) (19) Start of field IV Reference sub-carrier phase, colour field IV Note 1 – The numbering of specific lines is in accordance with new engine