25:
400:. Ancillary data is indicated by a 3-word packet consisting of 0, 3FF, 3FF (the opposite of the synchronization packet header), followed by a two-word identification code, a data count word (indicating 0 - 255 words of payload), the actual payload, and a one-word checksum. Other than in their use in the header, the codes prohibited to video payload are also prohibited to ancillary data payload.
268:
information. The C channel is further time-multiplexed into two half-bandwidth channels, known as Cr (the "red color difference" channel), and Cb (the "blue color difference" channel). The nominal datarate of the Y channel is 75 Mwords/sec (1.5 Gbit/s divided by 20), and the nominal datarate of
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The SMPTE 292 standard is a nominally 1.5 Gbit/s interface. Two exact bitrates are defined; 1.485 Gbit/s, and 1.485/1.001 Gbit/s. The factor of 1/1.001 is provided to allow SMPTE 292 to support video formats with frame rates of 59.94 Hz, 29.97 Hz, and 23.98 Hz, in order
408:
Within the active portion of the video, the data words correspond to signal levels of the respective video components. The luminance (Y) channel is defined such that a signal level of 0 mV is assigned the codeword 64 (40 hex), and 700 millivolts (full scale) is assigned the codeword 940 (3AC) . For
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interfaces were defined by SMPTE, over concerns that an electrical interface at that bitrate would be expensive or unreliable, and that an optical interface would be necessary. Such fears have not been realized, and the optical interfaces are seldom if ever used, and are likely to be deprecated in
421:
For portions of the vertical and horizontal blanking regions which are not used for ancillary data, it is recommended that the luma samples be assigned the code word 64 (40 hex), and the chroma samples be assigned 512 (200 hex); both of which correspond to 0 mV. It is permissible to encode analog
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or vertical interval test signals) without breaking the interface, but such usage is nonstandard (and ancillary data is the preferred means for transmitting metadata). Conversion of analog sync and burst signals into digital, however, is not recommended—and neither is necessary in the digital
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Video payload (as well as ancillary data payload) may use any 10-bit word in the range 4 to 1019 (004 to 3FB in hexadecimal) inclusive; the values 0-3 and 1020-1023 (3FC - 3FF) are reserved and may not appear anywhere in the payload. These reserved words have two purposes, for synchronization
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region). The synchronization packet consists of four 10-bit words. The first three words are always the same—0x3FF, 0, 0; the fourth consists of 3 flag bits, along with an error correcting code. As a result, there are 8 different synchronization packets possible.
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The flags bits found in the fourth word are known as H, F, and V. The H bit indicates the start of horizontal blank; and synchronization bits immediately preceding the horizontal blanking region must have H set to one. Such packets are commonly referred to as
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The standard also defines nominal bitrates of 3 Gbit/s, for 50/60 frame per second 1080P applications. This version of the interface is not used (and has not been commercially implemented); instead, either a dual-link extension of SMPTE 292M known as
171:
The "M" designator was originally introduced to signify metric dimensions. It is no longer used in listings or filenames. Units of the
International System of Units (SI) are the preferred units of measurement in all SMPTE Engineering Documents.
260:, and several other standards, are 20-bit standards; thus SMPTE 292M uses a 20-bit word size. Each 20-bit word consists of two 10-bit datums, coming from two logical (and parallel) data channels, one ("Y") which encodes
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the chroma channels, 0 mV is assigned the code word 512 (200 hex), -350mV is assigned a code word of 64 (0x40), and +350mV is assigned a code word of 960 (3C0). Note that the scaling of the luma and chroma channels is
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identical. The minimum and maximum of these ranges represent the preferred signal limits, though the video payload may venture outside these ranges (providing that the reserved code words of 0 - 3 and 1020 - 1023 are
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is used to scramble the data to reduce the likelihood that long strings of zeroes or ones will be present on the interface. The interface is self-clocking. Framing is done by detection of a special
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pattern, which appears on the (unscrambled) serial digital signal to be a sequence of twenty ones followed by forty zeroes; this bit pattern is not legal anywhere else within the data payload.
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Likewise, The V bit is used to indicate the start of the vertical blanking region; an EAV packet with V=1 indicates the following line (lines are deemed to start EAV) is part of the
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standard for ancillary data. Ancillary data is provided as a standardized transport for non-video payload within a serial digital signal; it is used for things such as embedded
185:
systems. The 1.485 Gbit/s version of the standard supports other frame rates in widespread use, including 60 Hz, 50 Hz, 30 Hz, 25 Hz, and 24 Hz.
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field, and a line count indicator. The CRC field provides a CRC of the preceding line (CRCs are computed independently for the Y and C streams), and can be used to detect
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Other than the fact that synchronization packets occur in parallel in two datastreams (Y and C), their behavior is virtually identical to the packet types defined in
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A synchronization packet occurs immediately before the first active sample on every line, and immediately after the last active sample (and before the start of the
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allowing for bit-rates of 1.485 Gbit/s, and 1.485/1.001 Gbit/s. These bit-rates are sufficient for and often used to transfer uncompressed
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SMPTE 274M-2005: Image Sample
Structure, Digital Representation and Digital Timing Reference Sequences for Multiple Picture Rates
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To provide additional robustness, the four samples immediately following the EAV packets (but not the SAV packets) contain a
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The SMPTE 292 digital interface is known to be reliable (without use of repeaters) at cable lengths of 100 m or greater.
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packets. Likewise, the packet appearing immediately before the start of the active video has H set to 0; this is the
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cable, intended to be used for transport of uncompressed digital video and audio in a television studio environment.
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443:. The honor recognized the society’s work on development, standardization, and productization of SMPTE 292.
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formats to indicate whether the line comes from the first or second field (or segment). In
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495:"SMPTE to Receive 2013 Technology and Engineering Emmy® Award for Work on HD-SDI Standard"
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in the interface. The line count field indicates the line number of the current line.
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SMPTE 292M-1998: Bit-Serial
Digital Interface for High Definition Television
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SMPTE 372M-2002: Dual Link 292M Interface for 1920 x 1080 Picture Raster
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SMPTE 291M-1998: Ancillary Data Packet and Space
Formatting
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The cabling used for the SMPTE 292 electrical interface is
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occur simultaneously in both the Y and C datastreams.
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Society of Motion
Picture and Television Engineers:
464:
Society of Motion
Picture and Television Engineers:
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Society of Motion
Picture and Television Engineers:
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Society of Motion
Picture and Television Engineers:
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each of the two chroma channels is 37.5 Mwords/sec.
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The corresponding parallel data formats, defined by
140:; it is part of a family of standards that define a
435:On July 31, 2013 it was announced that SMPTE won a
49:. Unsourced material may be challenged and removed.
775:NHK Science & Technology Research Laboratories
130:Society of Motion Picture and Television Engineers
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441:National Academy of Television Arts and Sciences
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264:video samples, the other ("C") which encodes
193:or a version running twice as fast known as
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348:, the digital interface commonly used for
337:formats, the F bit is always set to zero.
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521:"New Numbering Style for SMPTE Standards"
273:packets, and for ancillary data headers.
109:Learn how and when to remove this message
16:Digital video transmission line standard
437:Technology & Engineering Emmy Award
422:vertical interval information (such as
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200:
197:is used for e.g. 1080p60 applications.
181:to be upwards compatible with existing
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489:
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733:Advanced Television Systems Committee
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47:adding citations to reliable sources
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214:future revisions of the standard.
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765:Joint Photographic Experts Group
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726:Related standards organizations
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34:needs additional citations for
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235:linear feedback shift register
1:
753:ITU Radiocommunication Sector
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770:Moving Picture Experts Group
759:ITU Telecommunication Sector
712:Broadcast television systems
7:
748:European Broadcasting Union
717:Interoperable Master Format
331:progressive segmented frame
10:
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743:Digital Video Broadcasting
424:vertical interval timecode
380:, SMPTE 292 supports the
136:is usually referred to as
128:standard published by the
796:Film and video technology
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699:
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418:used for video payload).
289:Synchronization packets
142:serial digital interface
447:Related SMPTE standards
362:cyclic redundancy check
277:Synchronization packets
151:SMPTE 292 expands upon
501:. SMPTE. July 31, 2013
396:, and other sorts of
325:The F bit is used in
308:Start of Active Video
229:. Data is encoded in
221:cable with a nominal
161:high-definition video
356:Line counter and CRC
201:Electrical interface
43:improve this article
299:End of Active Video
283:horizontal blanking
124:is a digital video
134:technical standard
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320:vertical interval
205:Originally, both
176:Technical details
126:transmission line
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761:(formerly CCITT)
700:Related articles
681:SMPTE color bars
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523:. Archived from
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806:SMPTE standards
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527:on 2020-03-31.
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233:format, and a
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132:(SMPTE). This
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54:Find sources:
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32:This article
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738:BBC Research
525:the original
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503:. Retrieved
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167:Nomenclature
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41:Please help
36:verification
33:
505:October 16,
427:interface.
266:chrominance
248:Data format
144:based on a
58:"SMPTE 292"
790:Categories
676:SMPTE 2117
671:SMPTE 2071
666:SMPTE 2067
661:SMPTE 2059
656:SMPTE 2022
651:SMPTE 424M
646:SMPTE 421M
641:SMPTE 377M
636:SMPTE 372M
631:SMPTE 367M
626:SMPTE 360M
621:SMPTE 356M
616:SMPTE 344M
611:SMPTE 330M
606:SMPTE 296M
601:SMPTE 292M
596:SMPTE 291M
591:SMPTE 274M
586:SMPTE 268M
581:SMPTE 259M
478:References
431:Emmy award
366:bit errors
327:interlaced
207:electrical
99:April 2023
69:newspapers
686:SMPTE DCP
574:Standards
568:standards
382:SMPTE 291
378:SMPTE 259
346:SMPTE 259
262:luminance
258:SMPTE 296
254:SMPTE 274
223:impedance
195:SMPTE 424
191:SMPTE 372
157:SMPTE 344
153:SMPTE 259
122:SMPTE 292
398:metadata
394:timecode
342:CCIR 601
315:packet.
225:of 75
219:coaxial
211:optical
146:coaxial
83:scholar
138:HD-SDI
85:
78:
71:
64:
56:
566:SMPTE
416:never
386:audio
376:Like
301:, or
90:JSTOR
76:books
507:2013
350:SDTV
344:and
329:and
291:must
209:and
183:NTSC
155:and
62:news
411:not
313:SAV
311:or
303:EAV
231:NRZ
45:by
792::
497:.
486:^
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352:.
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558:e
551:t
544:v
509:.
227:Ω
112:)
106:(
101:)
97:(
87:·
80:·
73:·
66:·
39:.
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