SMPTE RP 2046-2-2009 Television C Safe Areas for Protection of Alternate Aspect Ratios《电视 交替宽高比防护的安全区域》.pdf

1、 Copyright 2009 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue., White Plains, NY 10601 (914) 761-1100 Approved November 23, 2009 Table of Contents Page Foreword 2 Intellectual Property 2 1 Scope . 3 2 Conformance Notation . 3 3 Normative References . 3 4 Safe Areas . 4 4.

2、1 16:9 Shoot to Protect 4:3 Central Area (AFD 1111) . 5 4.2 16:9 Shoot to Protect the Full 16:9 Image (AFD 1010) 6 Page 1 of 6 pages SMPTE RP 2046-2:2009 SMPTE RECOMMENDED PRACTICE for Television Safe Areas for Protection of Alternate Aspect Ratios SMPTE RP 2046-2:2009 Page 2 of 6 pages Foreword SMP

3、TE (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, including Standards,

4、 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 ITU. SMPTE Engine

5、ering Documents are drafted in accordance with the rules given in Part XIII of its Administrative Practices. SMPTE RP 2046-2 was prepared by Technology Committee 10E. Intellectual Property At the time of publication no notice had been received by SMPTE claiming patent rights essential to the impleme

6、ntation 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 2046-2:2009 Page 3 of 6 pages 1 Scope This

7、Recommended Practice specifies Safe Areas that should be used when composing 16:9 images that will be presented on both 4:3 and 16:9 aspect ratio displays. The choice of whether the image, having been captured in one aspect ratio, should be cropped for presentation in the other is dictated by creati

8、ve and business factors. This Practice is intended to offer guidance on how best to compose the image once the presentation decision has been made. The preferred display (cropped or not) should be signaled to downstream devices using Active Format Description (AFD) as defined in SMPTE 2016-1. The re

9、commended Safe Areas are defined in the context of the AFD states in SMPTE 2016-1, primarily using the Safe Area and Safe Title Areas defined in SMPTE ST 2046-1. 2 Conformance Notation Normative text is text that describes elements of the design that are indispensable or contains the conformance lan

10、guage 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 interoperability. Informative text does not contain any conformance keywords. All text in this doc

11、ument 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 requirements strictly to be followed in order to conform to the document and from which no deviati

12、on 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 certain course of action is preferred but not necessarily required; or that (in the negative form) a cer

13、tain 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” indicates a provision that is not defined at this time, shall not be used, and may be defined in t

14、he future. The keyword “forbidden” indicates “reserved” and in addition indicates that the provision 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 (“s

15、hould“) as described. A conformant implementation need not implement optional provisions (“may“) 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 auth

16、oritative definition; Tables shall be next; followed by formal languages; then figures; and then any other language forms. 3 Normative References The following standards contain provisions which, through reference in this text, constitute provisions of this recommended practice. At the time of publi

17、cation, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this recommended practice are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below. SMPTE 2016-1-2007, Television Format for

18、Active Format Description and Bar Data SMPTE ST 2046-1-2009, Specifications for Safe Action and Safe Title Areas for Television SMPTE RP 2046-2:2009 Page 4 of 6 pages SMPTE RP 221-2008, Specifications for Extraction of 4 3 Areas from Digital 16 9 Images for Television Systems ITU-R BT.1379-2 (09/07)

19、, Safe Areas of Wide-Screen 16:9 and Standard 4:3 Aspect Ratio Productions to Achieve a Common Format During a Transition Period to Wide Screen 16:9 Broadcasting 4 Safe Areas The Safe Areas for Protection of Alternate Aspect Ratios (hereafter referred to simply as Safe Areas) specified below are 90%

20、 of the width and 90% of the height of the part of the image to be extracted as specified in SMPTE 2016-1. The definition of Safe Area and the 90% width, 90% height shall be as specified in SMPTE ST 2046-1, with the following exceptions: Per SMPTE 2016-1, AFD 0011, AFD 1011, AFD 1101 and AFD 1110 sp

21、ecify a 14:9 extraction from 4:3 and 16:9 sources. For these cases only, where the source material is typically standard definition, the Safe Areas used shall be as specified in ITU-R BT 1379-2. The 90% width and 90% height coincide with the Safe Title Areas specified in SMPTE ST 2046-1, Sections 5.

22、1 through 5.4 (excluding the legacy safe areas of Section 5.4.) Although the percentages are the same, users should not confuse the Safe Areas specified in this Recommended Practice with those of SMPTE ST 2046-1. The Safe Areas specified here are illustrated with example graticules. The dimensions g

23、iven are normative, but the precise layout details of the graticules (line type, center cross, etc.) are informative. Horizontal dimensions are given in pixels; vertical dimensions are given in lines. Note: In Figures 1 and 2, the horizontal dimensions share a common center point and the vertical di

24、mensions share a common center point, as marked on the drawings. SMPTE RP 2046-2:2009 Page 5 of 6 pages 4.1 16:9 Shoot to Protect 4:3 Central Area (AFD 1111) This is described in SMPTE 2016-1 as “16:9 (with alternative 4:3 center)”. It is also commonly known as “center cut”. The Safe Area for center

25、-cut protection shall be the rectangle of width f and height e. The values for the dimensions shown in Figure 1 are given in Table 1. These values were calculated using the formulas in SMPTE RP 221. b eadfcFigure 1 Example Graticule for Center-Cut Protection Dimension Definition 1920 1080 1280 720 7

26、20 576 720 480 a Production aperture width 1920 1280 720 720 b Production aperture height 1080 720 576 480 c Center cut width 1440 960 540 540 d 16:9 safe area width 1728 1152 648 648 e Safe area height 972 648 518 432 f Center cut safe area width 1296 864 486 486 Table 1 Values for Center-Cut Prote

27、ction (Figure 1) SMPTE RP 2046-2:2009 Page 6 of 6 pages 4.2 16:9 Shoot to Protect the Full 16:9 Image (AFD 1010) This is described in SMPTE 2016-1 as “16:9 (center)”. It is commonly known as “letterbox”. AFD 0010 is identical except for the placement of the letterboxed image at the top of the 4:3 fr

28、ame rather than the center. As the entire 16:9 image is contained in the 4:3 frame, the Safe Area shall be the same as that specified in SMPTE ST 2046-1 for 16:9 images. This information is repeated in Figure 2. The dotted rectangle of height e is the virtual 4:3 image height; this is not part of th

29、e graticule but is shown for clarity. As the entire 16:9 height of the production aperture will be visible on 4:3 displays, users are strongly cautioned that this must be kept clear of extraneous elements. e b dacFigure 2 Example Graticule for Letterbox Dimension Definition 1920 1080 1280 720 720 576 720 480 a Production aperture width 1920 1280 720 720 b Production aperture height 1080 720 576 480 c Safe area width 1728 1152 648 648 d Safe area height 972 648 518 432 e Virtual 4:3 image height 1440 960 768 640 Table 2 Values for Letterbox (Figure 2)