1、SMPTE RP*l174 73 E 8357403 OOOOQ34 770 I RP 174-1 993 SMPTE RECOMMENDED PRACTICE Bit-Parallel Digital Interface for 4:4:4:4 Component Video Signal (Single Link) Table of contents 1 Scope 2 Normative references 3 General 4 Interface format 5 Electrical characteristics 6 Mechanical characteristics Ann
2、ex A ECL 1 OH000 parameters Annex B Connector characteristics Annex C Cable shield pin Annex D Connector orientation Annex E Monochrome operation Annex F Error detection and correction in the video timing reference signal Annex G Signal conversion (GBR to Y, CE, CR and inverse) Annex H Bibliography
3、1 Scope This practice describes the means of interconnecting digital video equipment operating in system M (525/60) and complying with the 4:4:4 encoding parameters as defined in CCIR Recommendation 601 -2, annex 1 with a nominal sampling frequency of 13.5 MHz. Provision is made to convey signal at
4、1 O-bit precision and to carry a fourth auxiliary channel as part of the signal multiplex (yielding 4:4:4:4 or 4x4 overall). The practice has application in the television studio over distances up to 100 m (320 ft). The char- acteristics of the interface are summarized below: 1.1 The video signal is
5、 transmitted in the form of three color-component signals and an auxiliary signal (G, B, RI and A or Y, Ce, CR, and A). 1.2 The video signal is transmitted at the 4:4:4 family level of CCIR 601-2, with a nominal Copyright 63 1993 by the SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Harts
6、dale Ave., White Plains, NY 10607 (914) 761 -1 1 O0 Page 1 of 17 pages sampling frequency of 13.5 MHz. Provision is made to convey signals at 1 O-bit precision. 1.3 The bits of the digital code words that describe the video signal are transmitted in a parallel arrangement using 1 O conductor pairs.
7、Each pair carries a multiplexed stream of bits (of the same significance) of each of the component signals. Accordingly, the bit rate used in each pair is nominally 54 Mbits/s. An eleventh conduc- tor pair carries a clock signal at 54 MHz. 1.4 The signals on the interface are transmitted using balan
8、ced conductor pairs for a distance up to 25 m (80 ft) without equalization and up to 100 m (320 ft) with appropriate equalization. 1.5 The interface consists of one transmitter and one receiver in a point-to-point connection. 1.6 Parameters of the signal format are chosen to facilitate conversion to
9、 and from a serial digital interface format. 1.7 The interface allows the transmission of appropriate ancillary signals that may be multiplexed into the data stream during video blanking intervals. 1.8 Where hexadecinal values are used, they are indicated by a subscript h, such as 3FFh; other values
10、 are decimal. 2 Normative references The following standard contains provisions which, through reference in this text, constitute provisions of this practice. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this A
11、pproved September 1,1993 SMPTE RP*L74 93 O 83574DL 0000415 627 01 RP 174-1993 practice are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. required sin x/x correction is at the point where the digital signal is converted to an analog for
12、mat. 3.4 Blanking interval SMPTE RP 157-1 990, Key Signals 3 General 3.1 Signal convention The signaling sense of the vcdge appearing across the interconnection cable is positive binary and defined as follows (refer to figure 1): 3.1.1 The A terminal of the transmitter shall be negative with respect
13、 to the B terminal for a binary O (LOW or L or OFF) state. 3.1.2 The A terminal of the transmitter shall be positive with respect to the B terminal for a binary 1 (HIGH or H or ON) state. 3.2 Signal names The data lines are designated DATA O through DATA 9. The group of 1 O signals is identified by
14、placing paren- theses around the range of subscripts included, as DATA (0-9). DATA 9 is always the most significant bit. 3.3 Sin x/x The characteristics of the data word at the interface are based on the assumption that the location of any This practice does not require the device feeding the interf
15、ace to transmit video data during the entire blanking interval. Therefore, ancillary information may be inserted into the horizontal blanking interval by the user within the constraints specified in 4.4 and 4.5. The vertical blanking duration is a minimum of nine lines. Ancillary information may be
16、inserted into this nine-line interval by the user within the constraints specified in 4.4 and 4.5. 3.5 Signal specifications All digital signal time intervals are specified at the half-amplitude points. All transitions are specified between the 20% and 80% amplitude points. 3.6 Electromagnetic inter
17、ference Digital apparatus can radiate a significant amount of energy at harmonics of the clock frequency. In the case of 13.5 MHz, clock harmonics lie at 121.5 MHz and 243 MHz, both of which are aeronautical distress frequencies. Equipment and system designers must, therefore, pay particular attenti
18、on to the provision of adequate screening. T = transmitter R = receiver A, A = the data line B, B = the return line Figure 1 - Positive binary signal convention Page 2 of 17 pages SMPTE RP*174 93 8357401 000041b 563 m RP 174-1993 4 Interface format 4.1 General description The interface consists of a
19、 unidirectional, 11 -pair interconnection between a transmitting equipment and a receiving equipment. Video data, timing ref- erence information, and ancillary signals are time multiplexed and transferred on 10 data pairs in NRZ form. An eleventh pair provides a synchronous clock. 4.2 Encoding param
20、eters Table 1 summarizes the encoding parameter values, which are in accordance with CCIR 601 -2. O 4.3 Interface characteristics Table 2 specifies the interface characteris- tics. a Table 1 - Encoding parameters Matrixing formulas: Number of samples per line: - each of the 3 video components - auxi
21、liary channel -total number of samples Sampling structure: Sampling frequency: . - - each of 3 video components - auxiliary channel Form of encoding: Correspondence between video signal levels and quantization levels: - each of the 3 primaries (G, B, R), the luminance signal (Y), and the auxiliary c
22、hannel. - each color-difference signal (CB, CR) Y = 0.299R + 0.587G + 0.1148 CB = 0.564 (8-Y) = 0.5008 - 0.169R - 0.331G CR = 0.713 (Fi-Y) = 0.500R - 0.41 9G - 0.081 B Total Active 858 720 858 720 3432 2880 Orthogonal: line, field, and frame repetitive. 13.5 MHz nominal 13.5 MHz nominal Uniformly qu
23、antized, PCM, 10 bits per sample, for each of the primary signals and the auxiliary channel. 877 quantization levels with the black corresponding to level 64 and the peak white level corresponding to level 940. 897 quantization levels symmetrically distributed about level 51 2, corresponding to the
24、zero signal. Table 2 - Interface characteristics Digital format: Parallel: 11 balanced signal pairs carrying clock and Interface clock: 54.0 MHz nominal Voltage levels: Driver impedance: Receiver impedance: 1 O data bits Standard ECL (10KH series) Standard ECL (1OKH series) 110 ohms nominal, balance
25、d Page 3 of 17 pages SMPTE RP*174 93 W 8357403 0000417 4TT RP 174-1993 4.4 Digital blanking relationship 4.4.1 Horizontal sync relationship Figure 2 shows the relationship between video signals in the digital and analog domains for 525-line systems. Figure 3 shows the multiplex structure. Transmitte
26、d during each active line are 2880 multi- plexed green, red, blue, and auxiliary or luminance, chrominance, and auxiliary values. Eight of the remaining 552 interface clock intervals are used to transmit synchronizing information; the other 544 interface clock intervals may be used to carry ancillar
27、y information. The first of these 3432 interface clock intervals is designated line word O for the purpose of reference only. The 3432 sample words per total line are, there- -7 fore, numbered O through 1715. Intervals O through 3431, inclusive, contain video data. The interface clock intervals occu
28、rring during digital blanking are designated 2880 through 3431. Intervals 2880 through 2883 are reserved for the end-of-active video (EAV) timing reference described in 4.5.4. Intervals 3428 through 3431 are reserved for the start-of-active-video (SAV) timing reference described in 4.5.4. The half-a
29、mplitude point of the leading (falling) edge of the analog horizontal sync signal shall be coincident with a sample point which would be con- veyed by word 2945, if carried across the interface. 4.4.2 Vertical sync relationship Figure 4 shows the relationship between video signals in the digital and
30、 analog domains for 525-line systems. h Instants tttttti pc VOr(U RP 174-1993 J CR Rounding Annex G (informative) Signal conversion (GBR to Y, Ce, CR and inverse) - + Y - 306 = 0.299 1024 b P - 578 X- + 512 WB c- 1024 ,+ Blue 117 - x1024 + 601 - I 0.587 1024 CB Rounding 730 - 0.713 1024 578 .I 0.564
31、 1024 117 1 024 - I 0.114 Figure G.l - Matrix GBR /Y, Ce, CR Page 16 of 17 pages - _ SMPTE RP*174 93 El 8357401 0000430 933 e -C RP 174-1993 1436 -512X- 1024 R - IL i + Red +A mc b Rounding - 731 A * - 1.m -512X- 1 024 731 - 0.714 1024 - b c6 - 352 - 0.344 I -352 -512X- 1 024 I . 1815 -1.m 1 024 b +
32、 + mc D- Rounding Figure 6.2 - Matrix Y, Ce, CR / GBR Blue Annex H (informative) Bibliography MIL-C-24308C, General Specifications for Connectors, Electric, Rectangular, Nonenvironmental, Miniature, Polar- zed Shell, Rack and Panel CCIR Recommendation 601 -2, Encoding Parameters of Digital Television for Studios available. CCIR Report 962-1, The Filtering, Sampling and Multiplex- ing for Digital Encoding of Colour Television Signals Documents are in preparation to cover auxiliary signals (HANC, VANC, DVITC, and video index), but are not yet Page 17 of 17 pages
