1、 Recommendation ITU-R BT.1203-2 (02/2015) User requirements for generic video bit-rate reduction coding of digital TV signals for an end-to-end television system BT Series Broadcasting service (television) ii Rec. ITU-R BT.1203-2 Foreword The role of the Radiocommunication Sector is to ensure the ra
2、tional, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radio
3、communication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1
4、of Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent infor
5、mation database can also be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television
6、) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service
7、systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2015 ITU 2015 All
8、 rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. RECOMMENDATION ITU-R BT.1203-2 User requirements for generic video bit-rate reduction coding of digital TV signals for an end-to-end television system (Question ITU-R 12/6) (1
9、995-2007-2015) Scope This Recommendation is intended to provide user requirements for video bit-rate reduction coding of digital TV signals for an end-to-end television system, with respect to picture formats, coding schemes, picture quality, etc. Keywords Video bit rate reduction, Satellite News Ga
10、thering (SNG) The ITU Radiocommunication Assembly, considering a) that rapid progress is being made in bit-rate reduction coding techniques; b) that video bit-rate reduction coding of digital TV signals has found wide applications for SNG1/ENG2, studio production, contribution, both primary and seco
11、ndary distribution and emission by terrestrial and satellite delivery; c) that in the total chain of broadcasting, a number of codecs will be used in a cascade, and this may lead to a loss of picture quality; d) that Recommendations ITU-T H.262 | ISO/IEC 13818-2 (MPEG-2 Video), H.264 | ISO/IEC 14496
12、-10 (MPEG-4 AVC) and H.265 | ISO/IEC 23008-2 (MPEG-H HEVC) are already used or proposed for codecs for the applications above; e) that there could be advantages to having generic (i.e. related) bit-rate reduction coding in the various applications so that maximum commonality among various applicatio
13、ns can be utilized; f) that interoperability should be achieved between different video formats and distribution media; g) that digital and analogue broadcasting systems will both exist during a transition period, recommends 1 that the same picture format or closely related signal formats should be
14、used as far as possible, throughout the broadcasting chain; 2 that the picture format of both input and output signals for coding and decoding should be the same; 1 The definition of SNG (Satellite News Gathering) can be found in Annex 1, 1.1 of Recommendation ITU-R SNG.770. 2 The definition of ENG
15、(Electronic News Gathering) can be found in Annex 3, 2 of Recommendation ITU-R SA.1154 and 3 of Report ITU-R BT.2069. 2 Rec. ITU-R BT.1203-2 3 that the same or closely related coding schemes should be used as much as possible for terrestrial and satellite emission and secondary distribution in order
16、 to minimize the receiver cost and the quality degradation; 4 that the encoder should as far as possible allow non-changing parameters that may be used in subsequent coding processes, e.g. motion information to be down-loaded into the subsequent codecs; 5 that the interface between the codecs should
17、 be simple, further recommends 1 that the values listed in Table 1 should be used for the input of the encoder and output of the decoder; 2 that the functional and operational requirements described in Table 6 should be satisfied; 3 that the benefits of generic coding applied to the total or parts o
18、f the total broadcasting chain should be studied in terms of ease of operation, equipment cost, and picture quality; 4 that the choice between Recommendation ITU-T H.262 | ISO/IEC 13818-2 (MPEG-2 Video), Recommendation ITU-T H.264 | ISO/IEC 14496-10 (MPEG-4 AVC)3, or Recommendation ITU-T H.265 | ISO
19、/IEC 23008-2 (MPEG-H HEVC) for the source coding method used by individual administrations should depend on a number of considerations including, for instance, interoperability with legacy equipment, efficient use of the bit rate available in the delivery channel, and harmonization with source codin
20、g methods adopted by neighbouring administrations for digital terrestrial and satellite broadcast channels. 3 Note from the Secretariat: Recommendations ITU-T H.262, H.264 and H.265 are available in electronic form at the ITU-T website. Rec. ITU-R BT.1203-2 3 Annex 1 TABLE 1 Input signal format for
21、codecs Items SNG/ENG Contribution Studio production Primary distribution Primary distribution Terrestrial emission Satellite emission Secondary distribution Mode 1(1) Mode 2(1) Case 1(2) Case 2(3) No. of samples/line and No. of lines/frame Examples are listed in Table 2 Colour format 4:2:0, 4:2:2 or
22、 4:4:4 should be used for the digital interface as per the specified studio formats. 4:2:0, 4:2:2 or 4:4:4 should be used for the digital interface as per the specified studio formats. (1) Mode 1: good transmission conditions. Mode 2: poor transmission conditions. (2) Case 1: digital primary distrib
23、ution followed by analogue secondary distribution or emission. (3) Case 2: digital primary distribution followed by digital secondary distribution or emission. 4 Rec. ITU-R BT.1203-2 TABLE 2 Examples of input picture formats for codecs Recommendation ITU-R Spatial resolution Frame frequency (Hz) Sca
24、nning BT.2020 7 680 4 320 120, 120/1.001, 100, 60, 60/1.001, 50, 30, 30/1.001, 25, 24, 24/1.001 Progressive 3 840 2 160 120, 120/1.001, 100, 60, 60/1.001, 50, 30, 30/1.001, 25, 24, 24/1.001 Progressive BT.709 1 920 1 080(1) 60, 60/1.001, 50, 30, 30/1.001, 25, 24, 24/1.001 Progressive 1 920 1 080(1)
25、30, 30/1.001, 25 Interlace BT.1543 1 280 720 60, 60/1.001, 30, 30/1.001 Progressive BT.1847 1 280 720 50 Progressive BT.601 720 576 25 Interlace 720 483(2) 30, 30/1.001 Interlace (1) For internal coding, the number of samples per line may be reduced to 1 440. (2) The number of coded lines may be 480
26、 in the case of emission and secondary distribution applications, although aspect ratio and the picture centre are defined using 483 active lines. NOTE 1 Tables 3 and 4 show information about profiles and levels defined in Recommendation ITU-T H.262. NOTE 2 Table 5 shows information about levels def
27、ined in Recommendation ITU-T H.264. NOTE 3 Table 6 shows information about levels defined in Recommendation ITU-T H.265. Rec. ITU-R BT.1203-2 5 TABLE 3 Upper bounds for sampling density and luminance sample rate currently in use among those specified in Recommendation ITU-T H.262 Level Profile Simpl
28、e Main High 4:2:2 (4:2:0) (4:2:2) High Samples/line lines/frame frames/s samples/s 1 920 1 088 60 62 668 800 1 920 1 088 60 83 558 400 1 920 1 088 60 62 668 800 1 920 1 088 60 62 668 800 High-1 440 Samples/line lines/frame frames/s samples/s 1 440 1 088 60 47 001 600 1 440 1 088 60 62 668 800 1 440
29、1 088 60 47 001 600 Main Samples/line lines/frame frames/s samples/s 720 576 30 10 368 000 720 576 30 10 368 000 720 576 30 14 745 600 720 576 30 11 095 200 720 608(1) 30 11 095 200 Low Samples/line lines/frame frames/s samples/s 352 288 30 3 041 280 (1) 512 lines/frame for 525/60, 608 lines/frame f
30、or 625/50. TABLE 4 Upper bounds for bit rates (Mbit/s) currently in use among those specified in Recommendation ITU-T H.262 Level Profile Simple Main High 4:2:2 High 80 100 300 High-1 440 60 80 Main 15 15 20 50 Low 4 6 Rec. ITU-R BT.1203-2 TABLE 5 Levels to be used among those specified in Recommend
31、ation ITU-T H.264 Level number Picture size (samples/line lines/frame) Frame frequency(1) (Hz) Maximum video bit rate(2) Maximum number of reference frames for picture size 3 720 480 720 576 30 25 10 Mbit/s 5 3.1 1 280 720 30 14 Mbit/s 5 3.2 1 280 720 60, 50 20 Mbit/s 4 4 1 920 1 080 30, 25, 24 20 M
32、bit/s 4 4.1 1 920 1 080 30, 25, 24 50 Mbit/s 4 4.2 1 920 1 080 60, 50 50 Mbit/s 4 5.1 3 840 2 160 30, 25, 24 240 Mbit/s 5 5.2 3 840 2 160 60, 50 240 Mbit/s 5 (1) Including those multiplied by 1000/1001 for 24, 30, 60, and 120 Hz. (2) For High, High 10, and High 4:2:2 profiles, the following bit-rate
33、 multipliers apply: High: 1.25, High 10: 3, High 4:2:2: 4 TABLE 6 Levels to be used among those specified in Recommendation ITU-T H.265 Level number Picture size (samples/line lines/frame) Frame frequency(1) (Hz) Maximum video bit rate(2) Maximum number of reference frames for picture size 3 720 480
34、 720 576 30 25 6 Mbit/s 8 8 3.1 1 280 720 30 10 Mbit/s 6 4 1 280 720 1 920 1 080 60, 50 30, 25, 24 12 Mbit/s 16 6 4.1 1 920 1 080 60, 50 20 Mbit/s 6 5 3 840 2 160 30, 25, 24 25 Mbit/s 6 5.1 3 840 2 160 60, 50 40 Mbit/s 6 5.2 3 840 2 160 120, 100 60 Mbit/s 6 6 7 680 4 320 30, 25, 24 240 Mbit/s 6 6.1
35、7 680 4 320 60, 50 480 Mbit/s 6 6.2 7 680 4 320 120, 100 800 Mbit/s 6 (1) Including those multiplied by 1000/1001 for 24, 30, 60, and 120 Hz. (2) In the case of Main Tier and Main 10 or Main Profile. Rec. ITU-R BT.1203-2 7 Annex 2 TABLE 7 Functional and operational requirements Item SNG/ENG Mode 1 S
36、NG/ENG Mode 2 Contribution Studio production Primary distribution Case 1 Primary distribution Case 2 Terrestrial emission Satellite emission Secondary distribution No. of audio channels BT.2020/UHDTV BT.709/HDTV BT.1543 and BT.1847 BT.601 /SDTV Minimum 2 Minimum 2 Minimum 2 Minimum 2 Maximum 24(5) M
37、aximum 8 Maximum 8 Maximum 6 Maximum 24(5) Maximum 6 Maximum 6 Maximum 6 Range of bit rates See Tables 3 to 6 Corresponds to SNG and contribution bit rates Corresponds to secondary distribution See Tables 3 to 6 Prediction mode(1) I, P (I, B, P) and (I, P) are used in non-live and live broadcasting,
38、 respectively Picture quality(2) 12%(3) 36%(3) 12%(3) 12%(3) 12%(3) 12%(4) Compatibility Not required Desirable Hierarchical coding Not required Required only for the graceful degradation system Scalability Not required, but if needed then lower quality can be obtained with a spatial interpolator De
39、sirable, needed for hierarchical coding Interoperability Not required A decoder should decode bit streams with as many picture formats as possible, but not necessarily all 8 Rec. ITU-R BT.1203-2 TABLE 7 (end) Item SNG/ENG Mode 1 SNG/ENG Mode 2 Contribution Studio production Primary distribution Case
40、 1 Primary distribution Case 2 Terrestrial emission Satellite emission Secondary distribution Editability Required in the bit stream domain Bit-rate flexibility A decoder should decode bit streams at any bit rate described in the item of “range of bit rates” Codec delay An overall delay of less than
41、 300 ms would be desirable for interactive talk-back applications Recovery time (after a break of 50 ms) 1 s 500 ms 500 ms Acquisition time The major contributions to acquisition time are the decoding delay and the interval between I pictures. A desirable figure for this value is less than 500 ms Er
42、ror concealment Required, a decoder should support this functionality and should also provide a signalling function of error conditions for studio applications Desirable Graceful degradation Not required Desirable, essential for mobile and portable reception Channel hopping latency Not required Less
43、 than 550 ms Relative delay between sound and vision 2 ms per codec(3) 2 ms per codec(4) (1) I: I-picture, P: P-picture, B: B-picture. (2) When DSCQS (Double Stimulus Continuous Quality Scale) method is used. DSIS (Double Stimulus Impairment Scale) method may be used alternatively. (3) See Recommend
44、ation ITU-R BT.1868. (4) See Recommendation ITU-R BT.1122. (5) See Recommendation ITU-R BS.2051. Rec. ITU-R BT.1203-2 9 Attachment4 Definition and explanation of items listed in Tables 1, 3, 5, 6, and 7 Generic coding: digital coding of pictures based on a family of related coding methods. No. of sa
45、mples/line: number of luminance samples per active line. No. of lines/frame: number of vertical lines per active frame. Colour format: ratio between the number of the luminance pixels and the number of the co-sited chroma difference pixels or the ratio between the colour pixels R, G, and B. No. of a
46、udio channels: total number of sound channels per programme, together with a description of how these channels can be combined for different applications. Range of bit rates: minimum and maximum encoder output bit rates for several input formats. Prediction mode: type of prediction used inside the e
47、ncoder. This very strongly influences the maximum achievable picture quality of the following codecs. Picture quality: results of the subjective evaluation of the encoding and decoding performance in an error-free channel. Compatibility: description of whether the bit stream syntax allows the separa
48、te signal processing of parts of the total bit stream in subsequent codecs. Hierarchical coding: method to achieve different resolution layers on the decoder side. Scalability: access to several picture qualities in a single bit stream. Interoperability: description of the grade of commonality betwe
49、en different bit streams inside the broadcasting chain. Editability: ability to edit a programme taking into account the structure of the encoder output data. Bit-rate flexibility: the coding algorithm may allow the use of either CBR (constant bit rate) or VBR (variable bit rate) coding. Codec delay: the delay introduced by the coding/decoding algorithm. Recovery time: the time period between a physical interruption inside the broadcasting chain and the achievement of full functionality. Acqui
