1、 Copyright 2014 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 Approved February 20, 2014 Table of Contents Page Foreword . 2 Intellectual Property 2 Introduction 2 1 Scope . 3 2 Conformance Notation . 3 3 Normative References . 4 4 D
2、efinitions 4 4.1 Transcode . 4 4.2 ATC . 4 4.3 Fr . 4 4.4 Tr . 4 4.5 Frame Pair 4 4.6 TFM . 5 4.7 Two-Frame Alignment . 5 4.8 Two-Frame-Capable . 5 4.9 Two-Frame Capability . 5 4.10 PCM 5 4.11 Non-PCM Audio 5 4.12 Non-PCM Data Block 5 5 Two-Frame Marker Specification and Carriage . 5 5.1 Two-Frame M
3、arker Packet Specification . 5 5.2 Placement of the Ancillary Data Packet . 6 6 Use of the Two-Frame Marker . 6 6.1 Two-Frame Marker and Two-Frame Capability (Normative) . 6 6.2 Conditions for Two-Frame Capability (Normative) . 6 6.3 Examples of Use of the Two-Frame Marker (Informative) . 6 6.4 Proc
4、essing Equipment Actions on Fr/2 Services in Fr Progressive Video (Informative) . 7 6.5 Sourcing Equipment Actions on Fr/2 Services in Fr Progressive Video (Informative) 9 6.6 Non-Two-Frame-Capable Equipment (Informative) . 9 Annex A Bibliography (Informative) . 10 Annex B Description of Two Frame M
5、arker Issue (Informative) 11 Page 1 of 12 pages SMPTE ST 2051:2014 Revision of SMPTE ST 2051:2010 SMPTE STANDARD Two-Frame Marker for 48(/1.001)-Hz, 50-Hz, and 60(/1.001)-Hz Progressive Digital Video Signals on 1.5 Gb/s and 3 Gb/s Interfaces SMPTE ST 2051:2014 Page 2 of 12 pages Foreword SMPTE (the
6、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, Recomme
7、nded 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 Engineering Do
8、cuments are drafted in accordance with the rules given in its Standards Operations Manual. SMPTE ST 2051 was prepared by Technology Committee 33TS. Intellectual Property At the time of publication no notice had been received by SMPTE claiming patent rights essential to the implementation of this Sta
9、ndard. 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. Introduction This section is informative and does not form an integral part of this
10、 Engineering Document. Problems can arise in video formats of frame rate Fr that transport Fr/2 ancillary data services; 48(/1.001)-Hz, 50-Hz, and 60(/1.001)-Hz progressive video signals are examples of such formats and are the subject of the provisions of this Standard. There is a 50% chance that a
11、 SMPTE RP 168 video switch will cut across the middle of an ancillary data block of length 2Tr = 2/Fr, causing the entire ancillary data block to fail its continuity check, and be dropped. By forcing video switches to have two-frame (frame pair) granularity aligned with the boundaries between the 2T
12、r-length data blocks of the ancillary data service, this problem can be eliminated. Other processing functions besides switches may also be dependent on frame pair alignment. These include Ancillary Time Code (ATC), de-interlacing processes that create video distortion with period 2/Fr, and multi-ch
13、annel audio program material encoded into data blocks spanning 2/Fr and embedded into ancillary data space. SMPTE ST 2051:2014 Page 3 of 12 pages 1 Scope This standard defines a Two-Frame Marker for progressive HDTV video formats at 48/1.001(47.95)-Hz, 48-Hz, 50-Hz, 60/1.001(59.94)-Hz, and 60-Hz fra
14、me rates. This Two-Frame Marker is multiplexed into serial streams carrying such a video format to govern the alignment of system actions such as switching to the data block boundaries of embedded ancillary data services having one half the frame rate (Fr/2) compared to the video frame rate (Fr). Re
15、quirements for use of this Two-Frame Marker are also defined in this standard. Note1: Users should be aware that equipment manufactured prior to the publication of this standard typically will not comply with its requirements. Note2: Use of the Two-Frame Marker is optional with progressive video str
16、eams at 48/1.001(47.95)-Hz, 48-Hz, 50-Hz, 60/1.001(59.94)-Hz, and 60-Hz frame rates mapped to interlaced serial interfaces at 24/1.001(23.98)-Hz, 24-Hz, 25-Hz, 30/1.001(29.97)-Hz, and 30-Hz frame rates, respectively. Note3: Use of the Two-Frame Marker is optional with progressive segmented frame vid
17、eo streams at 24/1.001(23.98)-Hz, 24-Hz, 25-Hz, 30/1.001(29.97)-Hz, and 30-Hz frame rates mapped to interlaced serial interfaces at 24/1.001(23.98)-Hz, 24-Hz, 25-Hz, 30/1.001(29.97)-Hz, and 30-Hz frame rates, respectively. 2 Conformance Notation Normative text is text that describes elements of the
18、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 interoperability. Informative text do
19、es 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 requirements strictly to be followed
20、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 certain course of action is preferred but n
21、ot 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” indicates a provision that is not def
22、ined 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. A conformant implementation according to this document is one that includes all mandatory provisions
23、(“shall“) and, if implemented, all recommended provisions (“should“) 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 do
24、cument 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. SMPTE ST 2051:2014 Page 4 of 12 pages 3 Normative References Note: All references in this document to other SMPTE do
25、cuments use the current numbering style (e.g. SMPTE ST 274:2008) although, during a transitional phase, the document as published (printed or PDF) may bear an older designation (such as SMPTE 274M-2008). Documents with the same root number (e.g. 274) and publication year (e.g. 2008) are functionally
26、 identical. 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
27、practice are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below. SMPTE ST 12-2:2014, Transmission of Time Code in the Ancillary Data Space SMPTE ST 274:2008, Television 1920 x 1080 Image Sample Structure, Digital Representation and Digital
28、Timing Reference Sequences for Multiple Picture Rates SMPTE ST 291-1:2011, Ancillary Data Packet and Space Formatting SMPTE ST 296:2012, 1280 x 720 Progressive Image Sample Structure Analog and Digital Representation and Analog Interface SMPTE ST 318:1999, Television and Audio Synchronization of 59.
29、94- or 50-Hz Related Video and Audio Systems in Analog and Digital Areas Reference Signals SMPTE ST 337:2008, Format for Non-PCM Audio and Data in an AES3 Serial Digital Audio Interface SMPTE RP 168:2009, Definition of Vertical Interval Switching Point for Synchronous Video Switching 4 Definitions 4
30、.1 Transcode To decode a data service from a video stream and encode it into a video stream of a different format. 4.2 ATC Ancillary Time Code 4.3 Fr Frame rate in Hz of a video signal. 4.4 Tr Frame period in seconds of a video signal; equal to 1/Fr. 4.5 Frame Pair Two time-consecutive frames of a v
31、ideo signal for which there is a first frame and a second frame. SMPTE ST 2051:2014 Page 5 of 12 pages 4.6 TFM Two-Frame Marker; SMPTE ST 291-1-compliant packet containing a flag to identify the first frame and the second frame of a Frame Pair for a 48(/1.001)-Hz, 50-Hz, or 60(/1.001)-Hz progressive
32、 digital video signal with frame rate Fr. 4.7 Two-Frame Alignment The start of the first frame of a progressive video Frame Pair with frame rate Fr is aligned with the start of the first field of an interlaced or progressive segmented frame video signal or the frame start of an ancillary data servic
33、e having frame rate Fr/2. For Progressive video streams with frame rate Fr mapped to dual link interlace transports having frame rates Fr/2, the start of the first frame of a progressive video Frame Pair with frame rate Fr is aligned with the start of the first field of its interlaced transport. 4.8
34、 Two-Frame-Capable Equipment that is capable of generating and/or passing the Two-Frame Marker (TFM) in its Fr-frame-rate output video stream(s) so that the TFM, all Fr/2 ancillary data services mapped into the stream, and all Fr/2 reference signals related to the stream are in Two-Frame Alignment.
35、4.9 Two-Frame Capability Tense of Two-Frame-Capable. 4.10 PCM Pulse-Coded Modulation, resulting in digital word representations of linear audio samples. 4.11 Non-PCM Audio Audio program, possibly multichannel, compressed and formatted for transport per SMPTE ST 337. 4.12 Non-PCM Data Block Group of
36、audio samples in Non-PCM format temporarily associated with a video frame. 5 Two-Frame Marker Specification and Carriage 5.1 Two-Frame Marker Packet Specification The Two-Frame Marker shall be a SMPTE ST 291-1 Type 2 formatted packet with the following structure: The value of the DID shall be 46h. T
37、he value of the SDID shall be 01h. The value of the DC shall be 1. One byte shall be carried in the user data word of the ancillary data packet. Bit b0 shall be used to identify the first or second frame of a Frame Pair such that: b0 = 0 indicates the first frame of the Frame Pair b0 = 1 indicates t
38、he second frame of the Frame Pair Bits b7 to b1 are reserved and shall be set to 0. SMPTE ST 2051:2014 Page 6 of 12 pages 5.2 Placement of the Ancillary Data Packet The Two-Frame Marker packet shall be placed in the luminance (Y) data stream of the horizontal ancillary data space (HANC) defined by t
39、he relevant image formatting document for progressive video formats with 48/1.001, 48, 50, 60/1.001, or 60-Hz frame rate, (SMPTE ST 274 System #1, 2, or 3; or SMPTE ST 296 System #1, 2, or 3, or SMPTE ST 2048-2 System #1 to 5). The TFM packet shall be inserted into the luminance (Y) data stream of a
40、ny one line of the horizontal ancillary data space starting from the second line after the line of the switching point defined in RP168, and before the first line of active video. The specific packet location is detected by the receiver searching the horizontal ancillary data space for the DID and S
41、DID codes of the packet. 6 Use of the Two-Frame Marker 6.1 Two-Frame Marker and Two-Frame Capability (Normative) Equipment meeting the requirements of this standard shall be Two-Frame-Capable, according to the definition in Section 4. 6.2 Conditions for Two-Frame Capability (Normative) For equipment
42、 to be defined as being Two-Frame-Capable, Two-Frame Alignment shall be maintained between the output video stream at frame rate Fr and an interlaced reference signal input at frame rate Fr/2, according to the definition in Section 4. This reference signal can be either a SMPTE ST 318 composite anal
43、og video signal, or a tri-level sync signal derived from a SMPTE ST 274 system #4, 5, or 6 digital video stream or from a SMPTE ST 274 or SMPTE ST 2048-2 Progressive Segmented Frame digital video stream. When multiple data services at frame rate Fr/2 are also transported in the Fr frame rate video s
44、tream through Two-Frame-Capable equipment, the first frame shall be the same for all of them. 6.3 Examples of Use of the Two-Frame Marker (Informative) Figure 1 shows an example of a broadcast video plant carrying progressive video at frame rate Fr. A distributed interlaced reference signal at frame
45、 rate Fr/2 is used to synchronize all video paths throughout the plant. Two-Frame-Capable equipment is marked with an asterisk (*) in Figure 1. The interfaces transporting the progressive video may also be transporting various types of ancillary data, per SMPTE ST 291-1 provisions. The following are
46、 examples of alignment criteria between the ancillary data and the progressive video stream. Example: Transport of ATC in ancillary data: When ATC at frame rate Fr/2 is transported in Two-Frame-Capable equipment, the first frame of the output video stream(s) at frame rate Fr carries ATC_VITC1, or th
47、e first of two ATC_LTC packets having the same frame count. Example: Transport of Non-PCM Audio in ancillary data: When Non-PCM Audio at block rate Fr/2 is transported in Two-Frame-Capable equipment, the first frame of the output video stream(s) carries the first half of the Non-PCM Audio data block
48、. The alignments of ATC and Non-PCM Audio described above, and the alignments defined for other data services at frame rate Fr/2 to video at frame rate Fr, are commonly referred to as Two-Frame Alignment. SMPTE ST 2051:2014 Page 7 of 12 pages F SR E FR O U T E R / S W I T C H E R C O M P L E X- p r
49、o g r e s s i v e v i d e o a t f r a m e r a t e F rS Y M B O L L E G E N DC a m e r aT a p e S t o r a g eD i s k S t o r a g eF r a m e S y n cR e f e r e n c e G e n e r a t o rR E FS a t e l l i t e L i n k w V i d e o C o d e cF SF SF SF S*T w o - F r a m e - C a p a b l e*D i s t r i b u t e d I n t e r l a c e d R e f e r e n c e S i g n a l- a t f r a m e r a t e F r / 2L o c a l o r M a s t e r T i m e d*F i g u r e 2 : S y s t e m D i a g r a m E x a m p l e o f a T w o - F r a m e - C a p a b l e V i d e
