1、 Copyright 2012 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue., White Plains, NY 10601 (914) 761-1100 Approved April 18, 2012 Table of Contents Page Foreword . 2 Intellectual Property 2 Introduction 2 1 Scope . 32 Conformance Notation . 33 Normative References . 34 D-VITC
2、 General . 44.1 Signal Definition . 44.2 Data Assignment 44.3 Transitions 44.4 Digital Data . 74.5 Insertion Lines 7Annex A Bibliography (Informative) . 8Annex B 525-Line Signals (Informative) 9Annex C 625-Line Signals (Informative) 10Annex D Digital to Analog (D to A) Conversion (Informative) 11Ann
3、ex E Analog to Digital (A to D) Conversion (Informative) 12Page 1 of 12 pages SMPTE ST 266:2012 Revision of SMPTE 266M-2002 SMPTE STANDARD SD Digital Component Systems Digital Vertical Interval Time Code SMPTE ST 266:2012 Page 2 of 12 pages Foreword SMPTE (the Society of Motion Picture and Televisio
4、n Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United States of America, SMPTE has members in over 80 countries on six continents. SMPTEs Engineering Documents, including Standards, Recommended Practices, and Engineering Guideli
5、nes, are prepared by SMPTEs Technology Committees. Participation in these Committees is open to all with a bona fide interest in their work. SMPTE cooperates closely with other standards-developing organizations, including ISO, IEC and ITU. SMPTE Engineering Documents are drafted in accordance with
6、the rules given in Part XIII of its Administrative Practices. SMPTE ST 266 was prepared by Technology Committee 32NF. Intellectual Property At the time of publication no notice had been received by SMPTE claiming patent rights essential to the implementation of this Standard. However, attention is d
7、rawn to the possibility that some of the elements of this document may be the subject of patent rights. SMPTE shall not be held responsible for identifying any or all such patent rights. Introduction This section is entirely informative and does not form an integral part of this Engineering Document
8、. This revision of this document brings it into conformance with current SMPTE language and nomenclature requirements. It also recommends the use of SMPTE ST 12-2 as the time code standard for new implementations. The preferred method to carry SMPTE ST 12-1 time code in digital systems is per SMPTE
9、ST 12-2, Ancillary Time Code (ATC). This method is equally applicable to both Standard Definition and High Definition image formats. The use of D-VITC in new systems is discouraged. SMPTE ST 266:2012 Page 3 of 12 pages 1 Scope This standard defines the digital data representation of the digitized va
10、lues of the Digital Vertical Interval (VITC) code words defined in SMPTE ST 12-1. The intended use is with the standard definition (SD) digital coding given in SMPTE ST 125 (for 525-line, 59.94-Hz field rate, SD Digital component signals) or Recommendation ITU-R BT.601-7 and Recommendation ITU-R BT.
11、656 (for 625-line, 50-Hz field rate, SD Digital component signals). 2 Conformance Notation Normative text is text that describes elements of the design that are indispensable or contains the conformance language keywords: “shall“, “should“, or “may“. Informative text is text that is potentially help
12、ful to the user, but not indispensable, and can be removed, changed, or added editorially without affecting interoperability. Informative text does not contain any conformance keywords. All text in this document is, by default, normative, except: the Introduction, any section explicitly labeled as “
13、Informative“ or individual paragraphs that start with “Note:” The keywords “shall“ and “shall not“ indicate requirements strictly to be followed in order to conform to the document and from which no deviation is permitted. The keywords, “should“ and “should not“ indicate that, among several possibil
14、ities, one is recommended as particularly suitable, without mentioning or excluding others; or that a certain course of action is preferred but not necessarily required; or that (in the negative form) a certain possibility or course of action is deprecated but not prohibited. The keywords “may“ and
15、“need not“ indicate courses of action permissible within the limits of the document. The keyword “reserved” indicates a provision that is not defined at this time, shall not be used, and may be defined in the future. The keyword “forbidden” indicates “reserved” and in addition indicates that the pro
16、vision will never be defined in the future. A conformant implementation according to this document is one that includes all mandatory provisions (“shall“) and, if implemented, all recommended provisions (“should“) as described. A conformant implementation need not implement optional provisions (“may
17、“) and need not implement them as described. Unless otherwise specified, the order of precedence of the types of normative information in this document shall be as follows: Normative prose shall be the authoritative definition; Tables shall be next; followed by formal languages; then figures; and th
18、en any other language forms. 3 Normative References Note: All references in this document to other SMPTE documents may use the current numbering style (e.g. SMPTE ST 125:1995) although, during a transitional phase, the document as published (printed or PDF) may bear an older designation (such as SMP
19、TE 125M-1995). Documents with the same root number (e.g. 125) and publication year (e.g. 1995) are functionally identical. The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were
20、 valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below. SMPTE ST 125:1995, Television Component Video Signal 4:2:2 Bit-Parallel Digital Interfac
21、e SMPTE ST 266:2012 Page 4 of 12 pages SMPTE ST 12-1:2008, Television Time and Control Code Recommendation ITU-R BT.601-7 (2011), Studio Encoding Parameters of Digital Television for Standard 4:3 and Wide-Screen 16:9 Aspect Ratios Recommendation ITU-R BT.656-5 (2007), Interface for Digital Component
22、 Video Signals in 525-Line and 625-Line Television Systems Operating at the 4:2:2 Level of Recommendation ITU-R BT.601 4 D-VITC General 4.1 Signal Definition The D-VITC codeword shall be the VITC codeword as specified by SMPTE ST 12-1, Section 10 (“Vertical Interval Application”). D-VITC is an 8-bit
23、 digital data representation of the VITC codeword which is band-limited to permit a compatible analog conversion to a vertical interval time code (VITC) waveform approximating SMPTE ST 12-1 (see Annex E). The 8 bits of D-VITC shall be carried in the 8 most significant bits of the 10 bits of the SMPT
24、E ST 125 or Recommendation ITU-R BT.601 coding. Since some equipment may be built using only 8 of the 10 bits, both 10- and 8-bit interpretations of the values are given in this standard, with 10 bits the preferred expression and 8 bits given in parentheses. Note: See Annex D and Annex E for additio
25、nal information on conversion to and from the analog domain. 4.2 Data Assignment The 90 bits of the VITC codeword defined in SMPTE ST 12-1 shall be carried by 675 consecutive luma samples (see figure 1) of the data stream defined in SMPTE ST 125 and Recommendation ITU-R BT.601. Each VITC bit is ther
26、efore represented by 7.5 luma samples. The timing of the VITC bits on the digital line shall be as shown in Figure 2. The midpoint of the rise of bit 0 of the VITC codeword shall be coincident with luma sample number 26. 4.3 Transitions The shape of transitions between VITC bits is defined by the va
27、lues assigned to luma samples in the transition region. Because the number of luma samples chosen is an odd integer multiple (15) of one-half the total number of VITC bits per line, it is necessary to define two distinct transition data sets (see the lower drawing in Figure 2). Note: When viewed in
28、the analog domain, the resulting transitions are a close approximation to a raised cosine shape. SMPTE ST 266:2012 Page 5 of 12 pages VITC bit no. Value (weight) Assigned Use VITC bit no. Value (weight) Assigned Use VITC bit no. Value (weight) Assigned Use 0 1 VITC SYNC BITS 30 1 VITC SYNC BITS 60 1
29、 VITC SYNC BITS 1 0 31 0 61 0 2 (1) FRAME UNITS 32 (10) SECOND TENS 62 (1) HOUR UNITS 3 (2) 33 (20) 63 (2) 4 (4) 34 (40) 64 (4) 5 (8) 35 FLAG FLAG 65 (8) 6 (LSB) FIRST BINARY GROUP 36 (LSB) FOURTH BINARY GROUP 66 (LSB) SEVENTH BINARY GROUP 7 | 37 | 67 | 8 | 38 | 68 | 9 (MSB) 39 (MSB) 69 (MSB) 10 1 V
30、ITC SYNC BITS 40 1 VITC SYNC BITS 70 1 VITC SYNC BITS 11 0 41 0 71 0 12 (10) FRAME TENS 42 (1) MINUTE UNITS 72 (10) HOUR TENS 13 (20) 43 (2) 73 (20) 14 FLAG (See Note 1) 44 (4) 74 FLAG (See Note 1) 15 FLAG (See Note 1) 45 (8) 75 FLAG (See Note 1) 16 (LSB) SECOND BINARY GROUP 46 (LSB) FIFTH BINARY GR
31、OUP 76 (LSB) EIGHTH BINARY GROUP 17 | 47 | 77 | 18 | 48 | 78 | 19 (MSB) 49 (MSB) 79 (MSB) 20 1 VITC SYNC BITS 50 1 VITC SYNC BITS 80 1 VITC SYNC BITS 21 0 51 0 81 0 22 (1) SECOND UNITS 52 (10) MINUTE TENS 82-89 VITC CRC CODE 23 (2) 53 (20) 24 (4) 54 (40) 25 (8) 55 FLAG (See Note 1) 26 (LSB) THIRD BI
32、NARY GROUP 56 (LSB) SIXTH BINARY GROUP 27 | 57 | 28 | 58 | 29 (MSB) 59 (MSB) Note 1: Flag bits are as specified by SMPTE ST 12-1. Figure 1 SMPTE ST 12-1 VITC bit assignment (Informative) 90 Bits 50.00 uSec1 Horizontal Period0 502 26 72306 52 56 7632 6010 3612 4016 20 62 6646 7022 80 82 8942FrameUnit
33、sBinaryGroup1CRCHourTensBinaryGroup8HourUnitsBinaryGroup7MinuteTensBinaryGroup6MinuteUnitsBinaryGroup5SecondTensBinaryGroup4SecondUnitsBinaryGroup3FrameTensBinaryGroup2SMPTE ST 266:2012 Page 6 of 12 pages CURVE A: Transition from even bit to odd bitCURVE B: Transition from odd bit to even bitE A VS
34、A VE A V14390Video Data Word: 1439 4T4TDigital lineblankingDigital active line 1440TT=1/27 MHzAnalog Horizontal SyncMultiplexed video dataCbCbCrYYY.CURVE ALuma Sample NumberValues (h)8-bit10-bit300 0A80F0250298 1A0040C02A3C94A668 1031322633342728353629304146424337383944404551525354474855564950575801
35、2CURVE B1473 (1465)Bit 4Bit 0 (Even bit)Bit 2 (Even bit)Bit 1 (Odd bit)Bit 3 (Odd bit)636553676955577173596183938587757779898191103105107109959711111399101115117035Video Data Word NumberFigure2D-VITCwaveformrepresentationandpositionindigitalvideosamplesSMPTE ST 266:2012 Page 7 of 12 pages 4.4 Digita
36、l Data In the following clauses, 10-bit values are given and preferred. Equivalent values for 8-bit representations used in earlier documentation of SMPTE ST 125 are given in parentheses. 4.4.1 Data value associated with a logical one The data value associated with a logical one shall be 300h (C0h).
37、 4.4.2 Data value associated with a logical zero The data value associated with a logical zero shall be 040h (10h). 4.4.3 Data value associated with transitions The data values of samples associated with transitions between VITC logical states shall be as specified in the lower drawing in Figure 2.
38、4.4.4 Data value associated with unused luma sample positions The data values of all luma samples of the active line period which are not included in the D-VITC waveform shall be set to 040h (10h). 4.4.5 Data value associated with color difference sample positions The data values of all color differ
39、ence samples of the active line period shall be set to 200h (80h). 4.5 Insertion Lines For 525-line/60-field systems, the D-VITC shall be inserted on lines 14 and 277. Insertion on lines 16 and 279 is optional. For 625-line/50-field systems, the D-VITC shall be inserted on lines 19 and 332. Insertio
40、n on lines 21 and 334 is optional. SMPTE ST 266:2012 Page 8 of 12 pages Annex A Bibliography (Informative) Note: All references in this document to other SMPTE documents may use the current numbering style (e.g. SMPTE ST 12-2:2008) although, during a transitional phase, the document as published (pr
41、inted or PDF) may bear an older designation (such as SMPTE 12-2M-2008). Documents with the same root number (e.g. 12-2) and publication year (e.g. 2008) are functionally identical. SMPTE ST 12-2:2008, Television Transmission of Time Code in the Ancillary Data Space SMPTE ST 266:2012 Page 9 of 12 pag
42、es Annex B 525-Line Signals (Informative) The timing relationship between analog VITC and D-VITC for 525-line, 59.94-Hz field rate signals is given in Figure B.1. Figure B.1 Timing relationship between analog VITC and D-VITC for 525/60 standard SMPTE ST 1252.593 sec10.963 sec2.1 sec min49.739 sec no
43、minal10.0 sec min50 secAnalog Horizontal SyncSample values 000 and XYZ(Luminance samples only)(EAV) (SAV)(EAV) (SAV)Analog VITC per SMPTE ST 12-1t=1/13.5MHz1 . 8920 . .720t122t2t2t16t675t19t26t15tSMPTE ST 266:2012 Page 10 of 12 pages Annex C 625-Line Signals (Informative) The timing relationship bet
44、ween analog VITC and D-VITC for 625-line, 50-Hz field rate signals is given in Figure C.1. Figure C.1 Timing relationship between analog VITC and D-VITC for 625/50 standard ITU-R BT.6012.296 sec11.704 sec1.9 sec min50.087 sec nominal11.2 sec min50 secAnalog Horizontal SyncSample values 000 and XYZ(L
45、uminance samples only)(EAV) (SAV)(EAV) (SAV)Analog VITC per SMPTE ST 12-1t=1/13.5MHz1 . 8920 . .720t132t2t2t12t675t19t26t15tSMPTE ST 266:2012 Page 11 of 12 pages Annex D Digital to Analog (D to A) Conversion (Informative) When D-VITC is D to A converted, the resulting analog signal could deviate fro
46、m the nominal values given in SMPTE ST 12-1. Table D.1 gives possible deviations. The deviations are a consequence of the use of the 13.5-MHz sampling frequency defined by the 4:2:2 digital data specification of SMPTE ST 125 and Recommendation ITU-R BT.601. Table D.1 Tolerance deviations VITC D-VITC
47、 SMPTE ST 12-1 SMPTE ST 266 DEVIATION 525-line 60-field systems Bit rate Hz 1,809,400 2% 1,800,000.0 9,400 90-bit duration s 49.739 1 50.0 + 0.261 625-line 50-field systems Bit rate Hz 1,796,875 2% 1,800,000.0 + 3,125 90-bit duration s 50.087 1 50.0 + 0.067 Bit rate Hz 1,800,000.0 12,500 90-bit dura
48、tion s 50.0 + 0.345 SMPTE ST 266:2012 Page 12 of 12 pages Annex E Analog to Digital (A to D) Conversion (Informative) Design engineers need to be aware that as a result of wider tolerances of the analog waveform in both amplitude and frequency, the values resulting when an analog VITC signal is A to D converted might differ from the defined digital values given in Figure 2. In addition, the process of Analog to Digital conversion followed by Digital to Analog conversion might result in a VITC signal waveform that deviates from the waveform defined in SMPTE ST 12-1.
