1、 Rec. ITU-R BT.1700 1 RECOMMENDATION ITU-R BT.1700 Characteristics of composite video signals for conventional analogue television systems (2005) The ITU Radiocommunication Assembly, considering a) that many countries have established analogue colour television broadcasting services based on the NTS
2、C, PAL or SECAM systems; b) that it would add further complications to the interchange of programmes to have a greater multiplicity of systems; c) that Recommendation ITU-R BT.1701 Characteristics of radiated signals of conventional analogue television systems, defines the radio-frequency specificat
3、ions; d) that Report ITU-R BT.2043 Analogue television systems currently in use throughout the world, gives information on different television systems used by different countries, recommends 1 that administrations wishing to implement an analogue composite colour television system should choose the
4、 production video signal characteristics of one of the television systems defined in Parts A, B and C. 2 Rec. ITU-R BT.1700 PART A NTSC signal format and specification For format specifications and signal waveforms, see SMPTE 170M-1999 Television Composite Analogue Video Signal NTSC for Studio Appli
5、cations. NOTE 1 In Japan, the following parameters have been implemented and deviate from those defined in SMPTE 170M-1999. NTSC analogue video signal specifications For applications in professional television production and post-production NTSC, video signals should be defined by the detailed param
6、eters given in SMPTE Standard 170M-1999. This Standard describes the composite analogue colour video signal for studio applications: NTSC, 525 lines, 59.94 Hz field rates, 2:1 interlace with an aspect ratio of 4:3. This Standard specifies the interface for analogue interconnection and serves as the
7、basis for the digital coding necessary for digital interconnection of NTSC equipment. The composite colour video signal contains an electrical representation of the brightness and colour of a scene being analysed (the active picture area) along defined paths (scan lines). The signal includes synchro
8、nizing and colour reference signals that allow the geometric and colorimetric aspects of the original scene to be correctly reconstituted at the display. The synchronizing and colour reference signals are placed in parts of the composite colour video signal that are not visible on a correctly adjust
9、ed display. Certain portions of the composite colour video signal that do not contain active picture information are blanked (forced below black level) in order to allow retrace of scanning beams in some types of cameras and display devices. The video signal representing the active picture area cons
10、ists of: a wideband luminance (brightness) component with set-up and no upper bandwidth limitation for studio applications; a pair of simultaneous chrominance (colouring) components, amplitude modulated on a pair of suppressed sub-carriers of identical frequency (fsc= 3.579545. MHz) in quadrature (i
11、.e. with a 90 difference in phase). The video signal representing the active picture area corresponds to the scanning of the image at uniform velocities from left to right and from top to bottom. The velocities are such that the picture is repetitively scanned on 525 nominally horizontal lines, with
12、 alternate lines scanned on each vertical pass. This process is described as 2:1 interlace. Parameter SMPTE 170M-1999 Value used in Japan 1 Black (set-up) level Table 1 0 2 Vertical blanking Table 3 0.07 -0.082 , where is the field period 3 Reference white Section 4.2 The adjustment of the chromatic
13、ity of studio monitor to a D-white at 9 300 K is also used Rec. ITU-R BT.1700 3 The aspect ratio of the active picture area is four units horizontally to three units vertically. The composite colour video signal is produced by an NTSC encoder that functions as follows: The input signals to an NTSC e
14、ncoder are time-coincident green, blue, and red video signals (G B R), with no set-up and of equal amplitude when conveying picture information with no colour content. Horizontal and vertical synchronizing signals and reference sub-carrier are also required. After low-pass filtering, the colour-diff
15、erence signals (B-Y and R-Y or I and Q) are fed to balanced, quadrature-phase, sub-carrier amplitude modulators. The modulated sub-carrier signals are added to the luminance signal, along with set-up, blanking, sync, and burst (a colour synchronizing signal) to form the composite output video signal
16、. There is a fixed frequency and phase relationship between the sub-carrier in the burst signal, the sub-carriers conveying the colour-difference signals, and the horizontal and vertical synchronizing signals. The luminance and colour-difference components of the composite colour video signal at the
17、 encoder output are time-coincident. NOTE 1 SMPTE Standard 170M-1999 is available in electronic form at the ITU website: http:/www.itu.int/ITU-R/study-groups/sg/sg6/SMPTE/ as well as in Annex 1 of this Recommendation. SMPTE Standard 170M-1999 refers to version 1999 only, which is the version approve
18、d, by administrations of Member States of the ITU and Radiocommunication Sector Members participating in the work of Radiocommunication Study Group 6 in application of Resolution ITU-R 1-3. By agreement between ITU and SMPTE, this version was provided and authorized for use by SMPTE and accepted by
19、ITU-R for inclusion in this Recommendation. Any subsequent version of SMPTE Standard 170M, which has not been accepted and approved by Radiocommunication Study Group 6 is not part of this Recommendation. For subsequent versions of SMPTE documents, the reader should access the SMPTE website: http:/ww
20、w.smpte.org. PART B PAL signal format and specification This Part provides information concerning signal level, timing, chrominance modulation characteristics, and baseband bandwidth characteristics of 525-line and 625-line PAL implementations. 4 Rec. ITU-R BT.1700 TABLE 1 Basic characteristics of v
21、ideo and synchronizing signals* Item Characteristic 525 PAL NOTE Future use of 525 PAL as a production standard is not recommended 625 PAL Argentina 625 PAL Future use of this standard as a production standard is not recommended. Values in brackets 1 Total number of lines per picture (frame) 525 625
22、 1a Number of active lines 483 576 2 Line frequency fH(colour) 15 734.26 Hz 0.0003% 15 625 Hz 0.00002% 3 Field frequency (field/s) 2fH /525 (60/1.001)2fH /625 4 Nominal video bandwidth There is no constraint in studio/production applications 5 Chrominance sub-carrier frequency fsc 3 575 611.49 5 Hz
23、4 433 618.75 1 Hz 3 582 056.25 5 Hz 6 Relationship between chrominance sub-carrier frequency fscand line frequency fHHscff4909= Hscff +=625141351Hscff+=62514917 7 Type of chrominance sub-carrier modulation Suppressed-carrier amplitude-modulation of two sub-carriers in quadrature 8 Luminance signal B
24、GRYEEEE += 114.0587.0299.0 BGREEE and, are gamma-pre-corrected primary signals 8a Assumed gamma of display device 2.8 9 Chrominance signals (colour difference) matrix equations )(493.0YBUEEE = )(877.0YRVEEE = Rec. ITU-R BT.1700 5 TABLE 1 Basic characteristics of video and synchronizing signals* Item
25、 Characteristic 525 PAL NOTE Future use of 525 PAL as a production standard is not recommended 625 PAL Argentina 625 PAL Future use of this standard as a production standard is not recommended. Values in brackets x y x y Red 0.630 0.340 0.64 0.33 Green 0.310 0.595 0.29 0.60 10a Assumed chromaticity
26、coordinates (CIE, 1931) for primary colours of receiver(1)Blue 0.155 0.070 0.15 0.06 10b Chromaticity coordinates for equal primary signals BGREEE = (reference white) (Illuminant C) x = 0.3101 y = 0.3162 (Illuminant D65) x = 0.3127 y = 0.3290 10c Attenuation of colour difference signals UE 20 dB at
27、3.6 MHz UE 20 dB at 4 MHz MHz3,6atdB20VE 10d Equation of composite colour signal )2(cos)2(sin tfEtfEEEscVscUYM+= where: YE see item 8 UE and VE see item 9 fSCsee item 5 The sign of the YE component is the same as that of the sub-carrier burst (changing for each line) (see item 10f) 10e Amplitude of
28、chrominance sub-carrier 22VUEEG += 135 relative to UE axis with the following polarity Field 1 2 3 4 5 6 7 8 Burst blanking sequence (see Figs. 8 and 9) I II III IV I II III IV Even line + + + + 10f Phase of chrominance sub-carrier burst (see Fig. 2) Odd line + + + + 6 Rec. ITU-R BT.1700 1700-01abgh
29、dcef7OH54312fFIGURE 1Line synchronization detailTABLE 1 Basic characteristics of video and synchronizing signals* Item Characteristic 525 PAL NOTE Future use of 525 PAL as a production standard is not recommended 625 PAL Argentina 625 PAL Future use of this standard as a production standard is not r
30、ecommended. Values in brackets 10g Synchronization of chrominance sub-carrier By chrominance sub-carrier reference signals on the line-blanking back porch 10h Synchronization of chrominance sub-carrier switching during line blanking By VE chrominance component of sub-carrier burst 11 Line synchroniz
31、ation See Table 2 12 Field synchronization See Table 3 *This PAL recommendation provides information concerning signal level, timing, modulation characteristics, and bandwidth characteristics. Although there may be different emission standards using the 625 PAL system, there is only one studio/produ
32、ction format. (1)Field 1 of the sequence of eight colour fields is defined as that field, where the phase UE of the extrapolated UE component (see item 9) of the video burst at the half amplitude point of the leading edge of the line synchronizing pulse of line 1 is in the range 90 UE 90. Rec. ITU-R
33、 BT.1700 7 1700-02+ 135 135ABA:B:Phase of the burst in odd lines of the first, second, fifth andsixth fields and in even lines of the third, fourth, seventhand eighth fields.Phase of the burst in even lines of the first, second, fifthand sixth fields and in odd lines of the third, fourth,seventh and
34、 eighth fields.0.877 (ER EY) = EV0.493 (E EY) = EUFIGURE 2Chrominance axes and phase of the sub-carrier synchronization burstTABLE 2 Details of line synchronizing signals (see Fig. 1) Symbol Characteristic 525 PAL NOTE Future use of 525 PAL as a production standard is not recommended 625 PAL Argenti
35、na 625 PAL Future use of this standard as a production standard is not recommended. Values in brackets H Nominal line period 1/fH Nominally 63.555 s1/fH Nominally 64 s a Line-blanking interval 10.5-11.0 s 12 + 0 0.3 s b Interval between time datum (OH) and back edge of line-blanking pulse 9.2 + 0.2
36、0.1 s 10.5 s c Interval between time datum (OH) and front porch 1.5 0.1 s 1.2 + 0.32 0.0 s 1.5 0.3 s d Duration of synchronizing pulse 4.7 0.1 s 4.7 0.2 s e Rise time (10 to 90%) of the edges of the line-blanking pulse 140 20 ns 300 100 ns 8 Rec. ITU-R BT.1700 Details of field-synchronizing waveform
37、s 1700-03jl m nOVFIGURE 3Signal at the beginning of each first field 625 PAL (see Note 5 of Fig. 4)See Fig. 5Second field First fieldTABLE 2 Details of line synchronizing signals (see Fig. 1) Symbol Characteristic 525 PAL NOTE Future use of 525 PAL as a production standard is not recommended 625 PAL
38、 Argentina 625 PAL Future use of this standard as a production standard is not recommended. Values in brackets f Rise time (10 to 90%) of the edges of the line-synchronizing pulses 140 20 ns 200 100 ns g Interval between time datum (OH) and start of sub-carrier burst 5.3 0.1 s 5.6 0.1 s h Duration o
39、f sub-carrier burst 2.52 0.28 s or 9 1 cycles 2.25 0.23 s or 10 1 cycles 2.51 0.28 s or 9 1 cycles 1 Blanking level-reference 0 mV 2 White level 700 mV 3 Synchronizing level 286 mV 300 mV 4 Difference between black and blanking level (“set-up”) 0-70 mV 0 mV 5 Burst amplitude peak-to-peak 316-317 mV
40、300 30 mV 7 Peak-to-peak composite signal 1 330 mV Rec. ITU-R BT.1700 9 1700-04jl m nOVSee Fig. 5First field Second fieldNote 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
41、-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
42、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.Note 5 Figures 3-7 are traditional analogue monochr
43、ome timing signals that also apply to the composite colour signal.Figures 8 and 9 show the vertical interval burst blanking signal sequences.FIGURE 4Signal at the beginning of each second field 625 PAL (see Note 5)1700-05sp qrsssH2H2Blanking levelSync level(The durations are measured between the hal
44、f-amplitude points on the appropriate edges)FIGURE 5Detail of equalizing and field-synchronizing pulses 525/625 PAL10 Rec. ITU-R BT.1700 1700-06jl m nOVFIGURE 6Signal at the beginning of each first field 525 PAL (see Note 5 of Fig. 4)See Fig. 5Field 2 Field 11700-07jl m nOVFIGURE 7Signal at the begi
45、nning of each second field 525 PAL (see Note 5 of Fig. 4)See Fig. 5Field 1 Field 2NOTE 1 indicates an unbroken sequence of edges of line-synchronizing pulses throughout the field blanking period. Rec. ITU-R BT.1700 11 TABLE 3 Details of field synchronizing signals (see Figs. 3-7) Symbol Characterist
46、ic 525 PAL NOTE Future use of 525 PAL as a production standard is not recommended 625 PAL Argentina 625 PAL Future use of this standard as a production standard is not recommended. Values in brackets Field period 525/2fHNominally 16.6833 ms 625/2fHNominally 20 ms j Field-blanking interval (for H and
47、 a, see Table 1) 20 H + 1.5 s (1 272.62 s) 25H + a J(1) Rise time (10 to 90%) of the edges of field-blanking pulses 140 20 ns K(1) Interval between front edge of field-blanking interval and front edge of first equalizing pulse 1.5 0.1 s 3 2 s l Duration of first sequence of equalizing pulses 3 H 2.5
48、 H m Duration of sequence of synchronizing pulses 3 H 2.5 H n Duration of second sequence of equalizing pulses 3 H 2.5 H p Duration of equalizing pulse 2.3 0.1 s 2.35 0.1 s q Duration of field-synchronizing pulse 27.1 s (nominal value) 27.3 0.1 s r Interval between field-synchronizing pulse 4.7 0.1 s 4.7 0.1 s s Rise time (10 to 90%) of synchronizing and equalizing pulses 140 20 ns 200 100 ns (1)Not indicated in the drawing. 12 Rec. ITU-R BT.1700 Burst-blanking sequences 1700-08CABABABABIVIIIIIIIIIIIIIV621626236246251234567621626236246251234567308 309 310 311 312 313 314 315 316 3
