1、 Table of contents 1 Scope 2 Normative references 3 General specifications 4 Mapping of vertical ancillary data packets 5 Extended video line data content 6 VAUX pack structures 7 Data mapping in a frame Annex A Abbreviations 1 Scope The purpose of this standard is to define a method to uniformly ma
2、p metadata and data essence present within vertical ancillary packets (VANC) on the serial digital Interface (SDI), into VAUX DIF blocks of a DV-based 25 Mb/s or 50 Mb/s stream. Additionally, the standard defines a mapping method that results in an increase of the video aperture by one video line (e
3、xtended video line) for the 25 Mb/s DV-based compression scheme. The VANC mapping is applicable to 525/60 and 625/50 signal formats that use the 25 Mb/s or 50 Mb/s DV-based compression system. The mapping of the extended video line is applicable only to the 25 Mb/s DV-based stream. This mapping proc
4、ess requires use of a 10-bit SDI interface for the incoming video signal. 2 Normative references 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 valid. All standards are
5、subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. ANSI/SMPTE 259M-1997, Television 10-Bit 4:2:2 Component and 4fscComposite Digital Signals Serial Digital Interfac
6、e SMPTE 291M-1997, Television Ancillary Data Packet and Space Formatting SMPTE 314M-1999, Television Data Structure for DV-Based Audio, Data and Compressed Video 25 and 50 Mb/s Page 1 of 16 pages SMPTE 376M-2003 Copyright 2002 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdal
7、e Ave., White Plains, NY 10607 (914) 761-1100 Approved March 17, 2003 SMPTE STANDARD for Television Mapping of Vertical Ancillary Data Packets (VANC) into VAUX DIF Blocks of DV-Based 25 Mb/s or 50 Mb/s Streams and Extended Video Line Data into VAUX DIF Blocks of DV-Based 25 Mb/s Stream SMPTE 376M-20
8、03 Page 2 of 16 pages SMPTE 374M-2003, Television Mapping of Vertical Ancillary Data Packets and Extended Video Line Data into Video DIF Blocks of a DV-Based 50 Mb/s DIF Stream Structure SMPTE RP 168-2002, Definition of Vertical Switching Point for Synchronous Video Switching 3 General specification
9、s Metadata and data essence can be carried in the ancillary space of the serial digital interface (SDI), or serial data transport interface (SDTI) video stream structure. The data is formatted according to SMPTE 291M as vertical ancillary packets located in VBI space. VANC packets are mapped into th
10、e VAUX DIF data area of the 25 or 50 Mb/s DV-based DIF streams. During the mapping process, the VANC packets are converted into digital ancillary packets (DANC) and these are then mapped into VAUX DIF blocks, VAUX packs, as defined in SMPTE 314M. A line number generator is used to identify the posit
11、ion of the VANC packet on the SDI signal interface to prevent a possible temporal skew. NOTE Data content identification carried in a DIF frame that is defined in SMPTE 314M or IEC 61834 is located in the VSC and VS packs of the VAUX DIF blocks. Designers should be aware that data identification pre
12、sent in the VSC and VS packs of the SMPTE 314M DIF frame differs from data ID present in IEC 61834. The VSC and VS packs carry not only the data content ID of DV-based data (SMPTE 314M), but may also carry ID for DV data defined in IEC 61834. The mapping method proposed in this standard is based on
13、use of two different VAUX pack structures (see figure 3), 5-byte and 75-byte. SMPTE 314M and IEC 61834 specify only a single 5-byte long VAUX pack structure and they do not support the 75-byte VAUX pack structure. Some broadcast operations require a larger video aperture than that defined by the DV-
14、based compression system standard. The nominal video aperture of the compressed signal in DV-based compression is defined in SMPTE 314M and is equal to 480 lines in 525 TV line systems and 576 lines in 625 TV line systems. The extended video line video information mapping extends the range of the no
15、minal compressed video aperture by one line in both 525- and 625-line systems. The enlarged video aperture ads line 525 in the 525- line system and line 623 in the 625-line system. In addition, this method can be applied to a user selectable single line video signal. These lines are not processed by
16、 the DV-based compression system, and are therefore mapped into the VAUX DIF blocks of the compressed DV-based stream. This standard defines only a mapping of an extended video line into 25 Mb/s VAUX DIF blocks. Mapping of an extended video line into 50 Mb/s DIF video blocks is defined in SMPTE 374M
17、. Due to a fixed size of the bit space within the VAUX DIF blocks, it is necessary to establish management of the mapped space so maximum benefit of the VAUX DIF block space is achieved (see note 1) NOTE 1 Designers should be aware that the size of VANC data can exceed the capacity of the VAUX packs
18、. It is the responsibility of the application to manage the mapping of VANC data into VAUX packs such that only complete VANC packets are mapped into VAUX DIF blocks. Where the VAUX capacity is exceeded, it is the responsibility of the application to manage this mapping in such a way as to minimize
19、the effect on system performance, of not mapping all of the VANC data. Processing of data content located in VANC packets uses a technique of directly mapping it into VAUX DIF blocks. Data content contained in the extended video line, applies additional 4:2:2/4:1:1 sampling rate conversion before th
20、e content is mapped into the VAUX DIF blocks. The structure of this standard is as shown below: Clause 3.1 describes the data mapping space in the VAUX DIF block; Clause 4 describes the VANC data; Clause 5 describes extended video line data; Clause 6 describes VAUX pack structure; Clause 7 describes
21、 data mapping in a frame. SMPTE 376M-2003 Page 3 of 16 pages 3.1 Organization of the VAUX DIF block payload Figure 1 shows the typical organization of a DIF sequence for 25 and 50 Mb/s stream structures as described in SMPTE 314M. The VAUX DIF block space consists of three VAUX DIF blocks VA 0,i; VA
22、 1,i; and VA 2,i located in each DIF sequence. Conforming to SMPTE 314M, payload space of each VAUX DIF block is further subdivided into 15 VAUX packs and each VAUX pack is 5-byte long (see figure 3a). These 5-byte long VAUX packs are used in any VAUX DIF blocks, regardless of odd or even DIF sequen
23、ce. This standard defines, as well, a different VAUX DIF block payload structure space (see figure 3b) that is not defined in SMPTE 314M. This new structure is a 75-byte long VAUX pack. The reason for additional structures is to increase payload efficiency. The 75-byte long VAUX pack is used with VA
24、UX DIF blocks VA 0,i and VA 1,i of an even DIF sequence, and VAUX DIF blocks VA 1,i and VA 2,i of an odd DIF sequence (see note 2). A typical DIF sequence (odd or even) containing VAUX DIF blocks for data placement in both DIF sequences is shown in figure 2. VAUX DIF block VA 2,i in an even DIF sequ
25、ence and VAUX DIF block VA 0,i in an odd DIF sequence contain mandatory VAUX packs called video source (VS) and video source control (VSC). These VAUX packs contain information about the video source and control information defined in other documents. VAUX DIF blocks limit the use of a space for dat
26、a placement to byte position number 3 to 77 as shown in figure 2. In VAUX DIF block VA 2,i in an even DIF sequence, data is mapped into byte position number 3 to 47; while in VAUX DIF block VA 0,i in an odd DIF sequence, data is mapped into byte position number 33 to 77 (see figure 2). NOTE 2 The DI
27、F VAUX payload capacity excluding the pack header is indicated below: In case of 25 Mb/s stream that uses the 5-byte VAUX Pack structure only: For 525/60 system: 4 bytes x (15 + 15 + 9) packs x 10 DIF sequences = 1560 bytes/frame For 625/50 system: 4 bytes x (15 + 15 + 9) packs x 12 DIF sequences =
28、1872 bytes/frame In the case of a 25 Mb/s stream that uses the combined 5-byte / 75-byte VAUX pack structure: For 525/60 system: (74 + 74 + 4 x 9) bytes x 10 DIF sequences = 1840 bytes/frame For 625/50 system: (74 + 74 + 4 x 9) bytes x 12 DIF sequences = 2208 bytes/frame In the case of a 50 Mb/s str
29、eam that uses the 5-byte VAUX pack structure only: For 525/60 system: 4 bytes x (15 + 15 + 9) packs x 20 DIF sequences = 3120 bytes/frame For 625/50 system: 4 bytes x (15 + 15 + 9) packs x 24 DIF sequences = 3744 bytes/frame In the case of a 50 Mb/s stream that uses the combined 5-byte / 75-byte VAU
30、X pack structure: For 525/60 system: (74 + 74 + 4 x 9) bytes x 20 DIF sequences = 3680 bytes/frame For 625/50 system: (74 + 74 + 4 x 9) bytes x 24 DIF sequences = 4416 bytes/frame SMPTE 376M-2003 Page 4 of 16 pages Figure 1 Organization of a typical DIF sequence structure Figure 2 VAUX payload area
31、for data for 25 or 50 Mb/s DIF blocks Odd DIF Sequence Even DIF Sequence Byte position number 3 2 1 0 79 77 3 2 1 0 79 77 3 2 1 0 79 77 48 47 3 2 1 0 79 77 32 33 3 2 1 0 79 77 3 2 1 0 79 77 ID Payload VA0,i ID Payload VA1,i ID Payload VA2,i * VSC * VS * Reserved ID Payload * VS * VSC * Reserved VA0,
32、i ID Payload VA1,i ID Payload VA2,i Where i: first/second channel VS: VAUX Source Pack VSC: VAUX Source Control Pack Refer to SMPTE 314 Byte 78, 79, reserved and filled with FFh Structure of a DIF Sequence DIF blocks Typical DIF Sequence a DIF Sequence n, i Header section Subcode section VAUX sectio
33、n Audio LE = 1 then LN bits are valid LE indicates whether the LN bits are valid or invalid (see note 3) NOTE 3 In the case of originally generated information that is placed in a DANC packet (e.g., UMID), LE may be set to 0 or 1, depending on which specific line might be preferred for the mapped da
34、ta location on the interface. LN: Line number a line number identifying where the original VANC packet was located. An internal television line number generator creates a LN number. This generator is reset at the beginning of every frame, corresponding to the start of a frame, as defined in relevant
35、 system standard and increments from 1 to n. For the 525/60 system LN0 - LN10 = 1, , 525 For the 625/50 system LN0 - LN10 = 1, , 625 Res: Reserved bit for future use Default value shall be set to 1. The total data size for all mapped DANC packets of a single frame can, at best, be equal to the data
36、capacity available in the existing payload of the VAUX DIF Blocks of a single frame. B0 B1 B2 B3 Bm SMPTE 376M-2003 Page 7 of 16 pages 4.1 Placement of VANC packets during data recovery into the SDI interface Placement of vertical ancillary data packets into the VBI (VANC) space may be accomplished
37、by the following means: a) If LE is set to zero, the placement of the VANC packets into the VBI ancillary space starts one line after the vertical switching point line as defined in SMPTE RP 168. The insertion of packets continues to the last line of the VBI before the start of an active video line
38、in a field. The placement of packets shall conform to SMPTE 291M rules requiring that ancillary packets are contiguous and left justified. A single line can carry multiple VANC packets as long as space is available. In this case the recovered VANC data packets are not located at the same place on th
39、e interface where they were originally located. b) If LE is set to one, the placement of the packets into the VBI ancillary space shall be determined by the line number LN indicted in the header of the DANC packet. Recovered VANC data packets are located at the same place on the interface where they
40、 were originally found. The placement of packets shall conform to SMPTE 291M rules requiring that ancillary packets are contiguous and left justified. 5 Extended video line data content (applicable to 25Mb/s DV-based compression) Figure 5 shows video data contained in an extended video line. In gene
41、ral, video lines of a standard definition television signal are sampled in 4:2:2 format. For the extended video line, the conversion of 4:2:2 sampled video data into 4:1:1 sampled video data is required. This type of processing assures that video content of the extended video line is the same as the
42、 rest of the compressed signal in a frame. Figure 5 Extended video line data 6 VAUX pack structures 6.1 Basic pack structure The process of mapping DANC packets into the VAUX DIF block payload shall utilize a structure based on VAUX packs (see figure 3). There are two types of VAUX packs, type 1 and
43、 type 2. A VAUX pack header located at byte position number 3 or 33 of a VAUX DIF block provides an identification of the relevant pack structure type. The DANC packet data mapping process uses 5-byte long structures (see figure 3a), while the extended video line video data shall use only the 75-byt
44、e pack structure (see figure 3b). Color difference (Cb,Cr) Cb0 Cb1 Cb2 Cb179 Cr0 Cr1 Cr2 Cr179 First pixel in active period : Transmitting samples : Discarded samples 1 / 6.75MHz Luminance (Y) 1 / 13.5MHz Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8 Y9 Y10 Y719 SMPTE 376M-2003 Page 8 of 16 pages 6.2 VAUX pack with 5-
45、byte long structure Two different types of 5-byte long VAUX packs are used for mapping each DANC packet. Tables 1 and 2 define the VAUX pack type 1 and type 2, respectively. Each pack construct consists of 5 bytes, where the first byte (PC0) of a pack serves as a pack header. The data of a single DA
46、NC packet is mapped into a single type 1 VAUX pack and multiple type 2 VAUX packs. The type 1 VAUX pack serves additionally as a start indicator of a DANC packet The type 1 VAUX pack and type 2 VAUX pack have different VAUX pack header values. Code of the first byte (PC0) E1h is associated with the
47、type 1 VAUXpPack and code E2h is associated with the type 2 VAUX pack. Byte 2 (PC1) of the VAUX pack type 1 contains Res bits. Res bits are reserved for future use and their default value is set to 1. Remaining bytes of the type 2 VAUX Pack (PC2, PC3, PC4) carry data from first 3 bytes of a DANC pac
48、ket B0, B1, B2. The type 2 of VAUX pack consists of a pack header (PC0) and a payload area (PC1, PC2, PC3 OLN8:0 = 12 If Line 525, O/E = 1; OLN8:0 = 253 For the 625/50 system If Line 22, O/E = 0; OLN8:0 = 16 If Line 623, O/E = 1; OLN8:0 = 305 7 Data mapping in a frame 7.1 Data mapping for a 25 Mb/s
49、DV-based DIF stream The VAUX DIF blocks are arranged in a block in the order of a single video frame as shown in table 4. The 5-byte long VAUX packs are used for the mapping of DANC packets data from a single video frame. Figure 7 Mapping video line data into extended video line VAUX packs Cr0, Cr1, Cr24, ., Cr179 Cb0, Cb1, Cb24, , Cb179 E 7Extended video line packs 72 bytes E 772 bytes
