1、 Copyright 2011 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 Approved December 5, 2011 Table of Contents Page Foreword . 2 Intellectual Property 2 1 Scope 3 2 Conformance Notation 3 3 Normative References 3 4 Usage 4 5 Synchronizing
2、 Signal . 4 6 Location . 4 Page 1 of 4 pages SMPTE RP 25:2011 Revision of RP 25-1995 SMPTE RECOMMENDED PRACTICE Audio and Picture Synchronization in Motion-Picture Film Relative to Leaders for Television and Theatrical Presentation for Magnetic and Photographic Records SMPTE RP 25:2011 Page 2 of 4 p
3、ages Foreword SMPTE (the Society of Motion Picture and Television 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, inc
4、luding Standards, Recommended Practices and Engineering Guidelines, 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 I
5、TU. SMPTE Engineering Documents are drafted in accordance with the rules given in Part XIII of its Administrative Practices. SMPTE RP 25 was prepared by Technology Committee 20F on Film Intellectual Property At the time of publication no notice had been received by SMPTE claiming patent rights essen
6、tial to the implementation of this Recommended Practice. However, attention is drawn 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. SMPTE RP 25:2011 Page 3 of 4 page
7、s 1 Scope It is the purpose of this practice to standardize the photographic and magnetic synchronizing signals and their position relative to the SMPTE Leaders for Television and Theatrical Presentation, as specified in SMPTE ST 55:2011 and SMPTE ST 301:2005. 2 Conformance Notation Normative text i
8、s 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 helpful to the user, but not indispensable, and can be removed, changed, or added editorially without affecting
9、 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 “Informative“ or individual paragraphs that start with “Note:” The keywords “shall“ and “shall not“ indicate
10、 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 possibilities, one is recommended as particularly suitable, without mentioning or excluding others; or that a certa
11、in 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 “need not“ indicate courses of action permissible within the limits of the document. The keyword “reserved”
12、 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 provision will never be defined in the future. Unless otherwise specified the order of precedence of the types
13、 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 then any other language forms. 3 Normative References Note: All references in this document to other SMPTE docu
14、ments use the current numbering style (e.g. SMPTE ST 301:2005) although, during a transitional phase, the document as published (printed or PDF) may bear an older designation (such as SMPTE 301-2005). Documents with the same root number (e.g. 301) and publication year (e.g. 2005) are functionally id
15、entical. The following standards contain provisions which, through reference in this text, constitute provisions of this recommended practice. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this recommended pra
16、ctice are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below. SMPTE ST 55:2011, Motion-Picture Film 35- and 16-mm Television Release Prints Leaders and Cue Marks SMPTE ST 301:2005, Motion-Picture Film - Theatre Projection Leader, Trailer an
17、d Cue Marks SMPTE RP 25:2011 Page 4 of 4 pages 4 Usage Two major areas for this synchronizing information are (a) in editing and rerecording operations and (b) in preparing printing materials in the laboratory. During the latter, the signal position may be used for visual and aural checking of synch
18、ronization of release prints. The synchronizing information, therefore, applies to both magnetic and photographic audio records. 5 Synchronizing Signal The synchronizing signal shall consist of a length equivalent to one picture frame of 1000 Hz sine wave 10%. Modulation shall be at least 80%. 6 Location The signal shall be so located on the audio track as to coincide with the single No. 2 (2-second) frame of the SMPTE Television Leader, or the single No. 3 (3-foot) frame of the SMPTE Theatre Projection Leader, when audio track and picture are aligned in editorial (parallel) sync.
