idnits 2.17.1 draft-ietf-payload-rtp-ancillary-02.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (October 19, 2015) is 3110 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Possible downref: Non-RFC (?) normative reference: ref. 'BT1120' -- Possible downref: Non-RFC (?) normative reference: ref. 'BT1700' ** Obsolete normative reference: RFC 4288 (Obsoleted by RFC 6838) -- Possible downref: Non-RFC (?) normative reference: ref. 'ST291' -- Obsolete informational reference (is this intentional?): RFC 2326 (Obsoleted by RFC 7826) Summary: 1 error (**), 0 flaws (~~), 1 warning (==), 5 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 A/V Transport Payloads Working Group T. Edwards 3 Internet-Draft FOX 4 Intended status: Standards Track October 19, 2015 5 Expires: April 21, 2016 7 RTP Payload for SMPTE ST 291 Ancillary Data 8 draft-ietf-payload-rtp-ancillary-02 10 Abstract 12 This memo describes an RTP Payload format for SMPTE Ancillary data, 13 as defined by SMPTE ST 291-1. SMPTE Ancillary data is generally used 14 along with professional video formats to carry a range of ancillary 15 data types, including time code, Closed Captioning, and the Active 16 Format Description (AFD). 18 Status of This Memo 20 This Internet-Draft is submitted in full conformance with the 21 provisions of BCP 78 and BCP 79. 23 Internet-Drafts are working documents of the Internet Engineering 24 Task Force (IETF). Note that other groups may also distribute 25 working documents as Internet-Drafts. The list of current Internet- 26 Drafts is at http://datatracker.ietf.org/drafts/current/. 28 Internet-Drafts are draft documents valid for a maximum of six months 29 and may be updated, replaced, or obsoleted by other documents at any 30 time. It is inappropriate to use Internet-Drafts as reference 31 material or to cite them other than as "work in progress." 33 This Internet-Draft will expire on April 21, 2016. 35 Copyright Notice 37 Copyright (c) 2015 IETF Trust and the persons identified as the 38 document authors. All rights reserved. 40 This document is subject to BCP 78 and the IETF Trust's Legal 41 Provisions Relating to IETF Documents 42 (http://trustee.ietf.org/license-info) in effect on the date of 43 publication of this document. Please review these documents 44 carefully, as they describe your rights and restrictions with respect 45 to this document. Code Components extracted from this document must 46 include Simplified BSD License text as described in Section 4.e of 47 the Trust Legal Provisions and are provided without warranty as 48 described in the Simplified BSD License. 50 Table of Contents 52 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 53 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 54 2. RTP Payload Format for SMPTE ST 291 Ancillary Data . . . . . 3 55 2.1. Payload Header Definitions . . . . . . . . . . . . . . . 5 56 3. Payload Format Parameters . . . . . . . . . . . . . . . . . . 7 57 3.1. Media Type Definition . . . . . . . . . . . . . . . . . . 8 58 3.2. Mapping to SDP . . . . . . . . . . . . . . . . . . . . . 9 59 3.3. Offer/Answer Model and Declarative Considerations . . . . 10 60 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 61 5. Security Considerations . . . . . . . . . . . . . . . . . . . 10 62 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 63 6.1. Normative References . . . . . . . . . . . . . . . . . . 11 64 6.2. Informative References . . . . . . . . . . . . . . . . . 11 65 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 12 67 1. Introduction 69 This memo describes an RTP Payload format for the Society of Motion 70 Picture and Television Engineers (SMPTE) Ancillary data (ANC), as 71 defined by SMPTE ST 291-1 [ST291]. ANC can carry a range of data 72 types, including time code, Closed Captioning, and the Active Format 73 Description (AFD). 75 ANC is generally associated with the carriage of metadata within the 76 bit stream of a Serial Digital Interface (SDI) such as SMPTE ST 259 77 [ST259], the standard definition (SD) Serial Digital Interface (with 78 ANC data inserted as per SMPTE ST 125 [ST125]), or SMPTE ST 292-1 79 [ST292], the 1.5 Gb/s Serial Digital Interface for high definition 80 (HD) television applications. 82 ANC data packet payload definitions for a specific application are 83 specified by a SMPTE Standard, Recommended Practice, Registered 84 Disclosure Document, or by a document generated by another 85 organization, a company, or an individual (an Entity). When a 86 payload format is registered with SMPTE, an application document 87 describing the payload format is required, and the registered 88 ancillary data packet is identified by a registered data 89 identification word. 91 This memo describes an RTP payload that supports ANC data packets 92 regardless of whether they originate from an SD or HD interface, or 93 if the ANC data packet is from the vertical ancillary space (VANC) or 94 the horizontal ancillary space (HANC), or if the ANC packet is 95 located in the luma (Y) or color-difference (C) channel. Sufficient 96 information is provided to enable the ANC packets at the output of 97 the decoder to be restored to their original locations in the serial 98 digital video signal raster (if that is desired). 100 It should be noted that the ancillary data flag (ADF) word is not 101 specifically carried in this RTP payload. The ADF may be specified 102 in a document defining an interconnecting digital video interface, 103 otherwise a default ADF is specified by SMPTE ST 291-1 [ST291]. 105 This ANC payload can be used by itself, or used along with a range of 106 RTP video formats. In particular, it has been designed so that it 107 could be used along with RFC 4175 [RFC4175] "RTP Payload Format for 108 Uncompressed Video" or RFC 5371 [RFC5371] "RTP Payload Format for 109 JPEG 2000 Video Streams." 111 The data model in this document for the ANC data RTP payload is based 112 on the data model of SMPTE ST 2038 [ST2038], which standardizes the 113 carriage of ANC data packets in an MPEG-2 Transport Stream. 115 1.1. Requirements Language 117 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 118 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 119 document are to be interpreted as described in RFC 2119 [RFC2119]. 121 2. RTP Payload Format for SMPTE ST 291 Ancillary Data 123 The format of an RTP packet containing SMPTE ST 291 Ancillary Data is 124 shown below: 126 0 1 2 3 127 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 128 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 129 |V=2|P|X| CC |M| PT | sequence number | 130 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 131 | timestamp | 132 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 133 | synchronization source (SSRC) identifier | 134 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 135 | Extended Sequence Number | Length | 136 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 137 | ANC_Count |C| Line_Number | Horizontal_Offset | 138 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 139 | DID | SDID | Data_Count | R | 140 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 141 | User_Data_Words... 142 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 143 | Checksum_Word |octet_align| (next ANC data packet)... 144 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 146 Figure 1: SMPTE Ancillary Data RTP Packet Format 148 RTP packet header fields SHALL be interpreted as per RFC 3550 149 [RFC3550], with the following specifics: 151 Timestamp: 32 bits 152 The timestamp field is interpreted in a similar fashion to 153 RFC 4175 [RFC4175]: 155 For progressive scan video, the timestamp SHALL denote the 156 sampling instant of the frame to which the ancillary data in 157 the RTP packet belongs. Packets MUST NOT include ANC data 158 from multiple frames, and all packets with ANC data belonging 159 to the same frame MUST have the same timestamp. 161 For interlaced video, the timestamp SHALL denote the sampling 162 instant of the field to which the ancillary data in the RTP 163 packet belongs. Packets MUST NOT include ANC data from 164 multiple fields, and all packets belonging to the same field 165 MUST have the same timestamp. 167 A 90-kHz timestamp SHOULD be used in both cases. If the 168 sampling instant does not correspond to an integer value of 169 the clock, the value SHALL be truncated to the next lowest 170 integer, with no ambiguity. 172 Marker bit (M): 1 bit 173 The marker bit set to "1" SHALL indicate the last RTP packet 174 containing ANC data for a frame (for progressive scan video) 175 or the last RTP packet containing ANC data for a field (for 176 interlaced video). 178 2.1. Payload Header Definitions 180 The ANC RTP payload header fields are defined as: 182 Extended Sequence Number: 16 bits 183 The high order bits of the extended 32-bit sequence number, 184 in network byte order. This is the same as the Extended 185 Sequence Number field in RFC 4175 [RFC4175]. 187 Length: 16 bits 188 Number of octets of the ANC RTP payload, beginning with the 189 "C" bit of the first ANC packet data. 191 ANC_Count: 8 bits 192 This field is the count of the total number of ANC data 193 packets carried in the RTP payload. A single ANC RTP packet 194 payload SHALL NOT carry more than 255 ANC data packets. 195 If more than 255 ANC data packets need to be carried in a 196 field or frame, additional RTP packets carrying ANC data may 197 be sent with the same RTP timestamp but with different 198 sequence numbers. 200 For each ANC data packet in the payload, the following ANC data 201 packet header fields MUST be present: 203 C: 1 bit 204 For HD signals, this flag, when set to "1", indicates that 205 the ANC data corresponds to the color-difference channel (C). 206 When set to "0", this flag indicates that the ANC data 207 corresponds to the luma (Y) channel. For SD signals, this 208 flag SHALL be set to "0". 210 Line_Number: 11 bits 211 This field contains the line number (as defined in ITU-R 212 BT.1700 [BT1700] for SD video or ITU-R BT.1120 [BT1120] for 213 HD video) that corresponds to the location of the ANC data 214 packet. A value of 0x7FF (all bits in the field are '1') 215 SHALL indicate that the ANC data is carried without a 216 specific line location within the field or frame. 218 Note that the lines that are available to convey ANC data are 219 as defined in the applicable sample structure specification 220 (e.g., SMPTE 274M [ST274], SMPTE ST 296 [ST296], ITU-R BT.656 222 [BT656]) and may be further restricted per SMPTE RP 168 223 [RP168]. 225 Horizontal_Offset: 12 bits 226 This field defines the location of the ANC packet relative to 227 the start of active video (SAV). A value of 0 means that the 228 Ancillary Data Flag (ADF) of the ANC packet begins 229 immediately following SAV. For HD, this SHALL be in units of 230 luma sample numbers as specified by the defining document of 231 the particular image (e.g., SMPTE 274M [ST274] for 1920 x 232 1080 active images, or SMPTE ST 296 [ST296] for 1280 x 720 233 progressive active images). For SD, this SHALL be in units 234 of (27MHz) multiplexed word numbers, as specified in SMPTE ST 235 125 [ST125]. A value of 0xFFF (all bits in the field are 236 '1') SHALL indicate that the ANC data is carried without any 237 specific location within the line. 239 Note that HANC space in the digital blanking area will 240 generally have higher luma sample numbers than any samples in 241 the active digital line. 243 An ANC packet with the header fields Line_Number of 0x7FF and 244 Horizontal_Offset of 0xFFF SHALL be considered to be carried without 245 any specific location within the field or frame, and in such a case 246 the "C" field SHALL be ignored. 248 For each ANC data packet in the payload, immediately after the ANC 249 data packet header fields, the following data fields MUST be present, 250 with the fields DID, SDID, Data_Count, User_Data_Words, and 251 Checksum_Word representing the 10-bit words carried in the ANC data 252 packet, as per SMPTE ST 291-1 [ST291]: 254 DID: 10 bits 255 Data Identification Word 257 SDID: 10 bits 258 Secondary Data Identification Word. Used only for a "Type 2" 259 ANC data packet. Note that in a "Type 1" ANC data packet, 260 this word will actually carry the Data Block Number (DBN). 262 Data_Count: 10 bits 263 The lower 8 bits of Data_Count, corresponding to bits b7 264 (MSB) through b0 (LSB) of the 10-bit Data_Count word, contain 265 the actual count of 10-bit words in User_Data_Words. Bit b8 266 is the even parity for bits b7 through b0, and bit b9 is the 267 inverse (logical NOT) of bit b8. 269 R: 2 reserved bits 270 R is a field of two reserved bits that MUST be set to zero. 272 User_Data_Words: integer number of 10 bit words 273 User_Data_Words (UDW) are used to convey information of a 274 type as identified by the DID word or the DID and SDID words. 275 The number of 10-bit words in the UDW is defined by the 276 Data_Count field. 278 Checksum_Word: 10 bits 279 The Checksum_Word can be used to determine the validity of 280 the ANC data packet from the DID word through the UDW. It 281 consists of 10 bits, where bits b8 (MSB) through b0 (LSB) 282 define the checksum value and bit b9 is the inverse (logical 283 NOT) of bit b8. The checksum value is equal to the nine 284 least significant bits of the sum of the nine least 285 significant bits of the DID word, the SDID word, the 286 Data_Count word, and all User_Data_Words in the ANC data 287 packet. The checksum is initialized to zero before 288 calculation, and any end carry resulting from the checksum 289 calculation is ignored. 291 octet_align: 0-7 bits as needed to complete octet 292 Octet align contains enough "0" bits as needed to complete 293 the last octet of an ANC packet's data in the RTP payload. 294 This ensures that the next ANC packet's data in the RTP 295 payload begins octet-aligned despite ANC packets being made 296 up of 10-bit words. If an ANC data packet in the RTP payload 297 ends aligned with an octet, there is no need to add any octet 298 alignment bits. 300 When reconstructing an SDI signal based on this payload, it is 301 important to place ANC packets into the locations indicated by the 302 ANC payload header fields Line_Number and Horizontal_Offset, and also 303 to follow the requirements of SMPTE ST 291-1 [ST291] Section 7 304 "Ancillary Data Space Formatting (Component or Composite Interface)", 305 which include rules on the placement of initial ANC data into allowed 306 spaces as well as the contiguity of ANC data packet sequences within 307 those spaces in order to assure that the resulting ANC packets in the 308 SDI signal are valid. 310 3. Payload Format Parameters 312 This RTP payload format is identified using the video/smpte291 media 313 type, which is registered in accordance with RFC 4855 [RFC4855], and 314 using the template of RFC 4288 [RFC4288]. 316 Note that the Media Type Definition is in the "video" tree due to the 317 expected use of SMPTE ST 291 Ancillary Data with video formats. 319 3.1. Media Type Definition 321 Type name: video 323 Subtype name: smpte291 325 Required parameters: 327 Rate: RTP timestamp clock rate. 329 Optional parameters: 331 DID_SDID: Data identification and Secondary data identification 332 words. 334 The presence of the DID_SDID parameters signals that all ancillary 335 data packets of this stream are of a particular type or types, 336 i.e., labeled with a particular DIDs and SDIDs. The DID_SDID 337 parameter consists of the DID and SDID values in that order 338 separated by a comma, with the DID/SDID pair preceded by a '{' and 339 followed by a '}'. 341 DID and SDID values should be specified in hexadecimal with a "0x" 342 prefix (such as "0x61"). For example, EIA 608 Closed Caption data 343 would be signalled with the parameter DID_SDID={0x61,0x02}. If 344 DID_SDID is not specified, then the ancillary data stream may 345 potentially contain ancillary data packets of any type. 347 Multiple DID_SDID parameters may be specified (separated by 348 semicolons) to signal the presence of multiple types of ANC data 349 in the stream. DID_SDID={0x61,0x02};DID_SDID={0x41,0x05}, for 350 example, signals the presence of EIA 608 Closed Captions as well 351 as AFD/Bar Data. 353 DID and SDID values of SMPTE Registered ANC packet types can be 354 found on the SMPTE Registry for Data Identification Word 355 Assignments at: 357 http://www.smpte-ra.org/S291/S291_reg.html 359 DID and SDID values can be registered with SMPTE as per SMPTE ST 360 291-1 [ST291]. 362 Encoding considerations: This media type is framed and binary; see 363 Section 4.8 of RFC 4288 [RFC4288]. 365 Security considerations: See Section 5 of [this RFC] 366 Interoperability considerations: Data items in smpte291 can be very 367 diverse. Receivers might only be capable of interpreting a subset of 368 the possible data items. Some implementations may care about the 369 location of the ANC data packets in the SDI raster, but other 370 implementations may not care. 372 Published specification: [this RFC] 374 Applications that use this media type: Devices that stream real-time 375 professional video, especially those that must interoperate with 376 legacy serial digital interfaces (SDI). 378 Additional Information: none 380 Person & email address to contact for further information: T. 381 Edwards , IETF Payload Working Group 382 384 Intended usage: COMMON 386 Restrictions on usage: This media type depends on RTP framing, and 387 hence is only defined for transfer via RTP RFC 3550 [RFC3550]. 388 Transport within other framing protocols is not defined at this time. 390 Author: T. Edwards 392 Change controller: IETF Audio/Video Transport Payloads working group 393 delegated from the IESG. 395 3.2. Mapping to SDP 397 The mapping of the above defined payload format media type and its 398 parameters SHALL be done according to Section 3 of RFC 4855 399 [RFC4855]. 401 o The type name ("video") goes in SDP "m=" as the media name. 403 o The subtype name ("smpte291") goes in SDP "a=rtpmap" as the 404 encoding name. 406 o The optional DID_SDID parameters go in the SDP "a=fmtp" attribute 407 as a semicolon-separated list of parameter=value pairs. 409 A sample SDP mapping for ancillary data is as follows: 411 m=video 30000 RTP/AVP 112 412 a=rtpmap:112 smpte291/90000 413 a=fmtp:112 DID_SDID={0x61,0x02};DID_SDID={0x41,0x05} 414 In this example, a dynamic payload type 112 is used for ancillary 415 data. The 90 kHz RTP timestamp rate is specified in the "a=rtpmap" 416 line after the subtype. The RTP sampling clock is 90 kHz. In the 417 "a=fmtp:" line, DID 0x61 and SDID 0x02 are specified (registered to 418 EIA 608 Closed Caption Data by SMPTE), and also DID 0x41 and SDID 419 0x05 (registered to AFD/Bar Data). 421 3.3. Offer/Answer Model and Declarative Considerations 423 When offering SMPTE ST 291 Ancillary data over RTP using the Session 424 Description Protocol (SDP) in an Offer/Answer model [RFC3264] or in a 425 declarative manner (e.g., SDP in the Real-Time Streaming Protocol 426 (RTSP) [RFC2326] or the Session Announcement Protocol (SAP) 427 [RFC2974]), the offerer could provide a list of streams available 428 with specific DID & SDIDs, and the answerer could specify which 429 streams with specific DID & SDIDs it would like to accept. 431 4. IANA Considerations 433 One media type (video/smpte291) has been defined and needs 434 registration in the media types registry. See Section 3.1 436 5. Security Considerations 438 RTP packets using the payload format defined in this specification 439 are subject to the security considerations discussed in the RTP 440 specification [RFC3550] and any applicable RTP profile, e.g., AVP 441 [RFC3551]. 443 To avoid potential buffer overflow attacks, receivers should take 444 care to validate that the ANC packets in the RTP payload are of the 445 appropriate length (using the Data_Count field) for the ANC data type 446 specified by DID & SDID. Also the Checksum_Word should be checked 447 against the ANC data packet to ensure that its data has not been 448 damaged in transit. 450 Some receivers will simply move the ANC data packet bits from the RTP 451 payload into a serial digital interface (SDI). It may still be a 452 good idea for these "re-embedders" to perform the above mentioned 453 validity tests to avoid downstream SDI systems from becoming confused 454 by bad ANC packets, which could be used for a denial of service 455 attack. 457 "Re-embedders" into SDI should also double check that the Line_Number 458 and Horizontal_Offset leads to the ANC data packet being inserted 459 into a legal area to carry ancillary data in the SDI video bit stream 460 of the output video format. 462 6. References 464 6.1. Normative References 466 [BT1120] ITU-R, "BT.1120-8, Digital Interfaces for HDTV Studio 467 Signals", January 2012. 469 [BT1700] ITU-R, "BT.1700, Characteristics of Composite Video 470 Signals for Conventional Analogue Television Systems", 471 February 2005. 473 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 474 Requirement Levels", BCP 14, RFC 2119, 475 DOI 10.17487/RFC2119, March 1997, 476 . 478 [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. 479 Jacobson, "RTP: A Transport Protocol for Real-Time 480 Applications", STD 64, RFC 3550, DOI 10.17487/RFC3550, 481 July 2003, . 483 [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and 484 Registration Procedures", RFC 4288, DOI 10.17487/RFC4288, 485 December 2005, . 487 [RFC4855] Casner, S., "Media Type Registration of RTP Payload 488 Formats", RFC 4855, DOI 10.17487/RFC4855, February 2007, 489 . 491 [ST291] SMPTE, "ST 291-1:2011, Ancillary Data Packet and Space 492 Formatting", 2011. 494 6.2. Informative References 496 [BT656] ITU-R, "BT.656-5, Interfaces for Digital Component Video 497 Signals in 525-Line and 625-Line Television Systems 498 Operating at the 4:2:2 Level of Recommendation ITU-R 499 BT.601", December 2007. 501 [RFC2326] Schulzrinne, H., Rao, A., and R. Lanphier, "Real Time 502 Streaming Protocol (RTSP)", RFC 2326, 503 DOI 10.17487/RFC2326, April 1998, 504 . 506 [RFC2974] Handley, M., Perkins, C., and E. Whelan, "Session 507 Announcement Protocol", RFC 2974, DOI 10.17487/RFC2974, 508 October 2000, . 510 [RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model 511 with Session Description Protocol (SDP)", RFC 3264, 512 DOI 10.17487/RFC3264, June 2002, 513 . 515 [RFC3551] Schulzrinne, H. and S. Casner, "RTP Profile for Audio and 516 Video Conferences with Minimal Control", STD 65, RFC 3551, 517 DOI 10.17487/RFC3551, July 2003, 518 . 520 [RFC4175] Gharai, L. and C. Perkins, "RTP Payload Format for 521 Uncompressed Video", RFC 4175, DOI 10.17487/RFC4175, 522 September 2005, . 524 [RFC5371] Futemma, S., Itakura, E., and A. Leung, "RTP Payload 525 Format for JPEG 2000 Video Streams", RFC 5371, 526 DOI 10.17487/RFC5371, October 2008, 527 . 529 [RP168] SMPTE, "RP 168:2009, Definition of Vertical Interval 530 Switching Point for Synchronous Video Switching", 2009. 532 [ST125] SMPTE, "ST 125:2013, SDTV Component Video Signal Coding 533 4:4:4 and 4:2:2 for 13.5 MHz and 18 MHz Systems", 2013. 535 [ST2038] SMPTE, "ST 2038:2008, Carriage of Ancillary Data Packets 536 in an MPEG-2 Transport Stream", 2008. 538 [ST259] SMPTE, "ST 259:2008, SDTV Digital Signal/Data - Serial 539 Digital Interface", 2008. 541 [ST274] SMPTE, "ST 274:2008, 1920 x 1080 Image Sample Structure, 542 Digital Representation and Digital Timing Reference 543 Sequences for Multiple Picture Rates", 2008. 545 [ST292] SMPTE, "ST 292-1:2012, 1.5 Gb/s Signal/Data Serial 546 Interface", 2012. 548 [ST296] SMPTE, "ST 296:2012, 1280 x 720 Progressive Image 4:2:2 549 and 4:4:4 Sample Structure - Analog and Digital 550 Representation and Analog Interface", 2012. 552 Author's Address 553 Thomas G. Edwards 554 FOX 555 10201 W. Pico Blvd. 556 Los Angeles, CA 90035 557 USA 559 Phone: +1 310 369 6696 560 Email: thomas.edwards@fox.com