1、 International Telecommunication Union ITU-T H.263TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2005) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSInfrastructure of audiovisual services Coding of moving video Video coding for low bit rate communication ITU-T Recommendation H.263 ITU-T H-SERIES
2、RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS H.100H.199 INFRASTRUCTURE OF AUDIOVISUAL SERVICES General H.200H.219 Transmission multiplexing and synchronization H.220H.229 Systems aspects H.230H.239 Communication procedures H.240H.259 Coding of moving
3、 video H.260H.279 Related systems aspects H.280H.299 Systems and terminal equipment for audiovisual services H.300H.349 Directory services architecture for audiovisual and multimedia services H.350H.359 Quality of service architecture for audiovisual and multimedia services H.360H.369 Supplementary
4、services for multimedia H.450H.499 MOBILITY AND COLLABORATION PROCEDURES Overview of Mobility and Collaboration, definitions, protocols and procedures H.500H.509 Mobility for H-Series multimedia systems and services H.510H.519 Mobile multimedia collaboration applications and services H.520H.529 Secu
5、rity for mobile multimedia systems and services H.530H.539 Security for mobile multimedia collaboration applications and services H.540H.549 Mobility interworking procedures H.550H.559Mobile multimedia collaboration inter-working procedures H.560H.569 BROADBAND AND TRIPLE-PLAY MULTIMEDIA SERVICES Br
6、oadband multimedia services over VDSL H.610H.619 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. H.263 (01/2005) i ITU-T Recommendation H.263 Video coding for low bit rate communication Summary This Recommendation specifies a coded representation that can be used f
7、or compressing the moving picture component of audio-visual services at low bit rates. The basic configuration of the video source coding algorithm is based on ITU-T Rec. H.261 and is a hybrid of inter-picture prediction to utilize temporal redundancy and transform coding of the remaining signal to
8、reduce spatial redundancy. The source coder can operate on five standardized video source formats: sub-QCIF, QCIF, CIF, 4CIF and 16CIF, and can also operate using a broad range of custom video formats. The decoder has motion compensation capability, allowing optional incorporation of this technique
9、in the coder. Half pixel precision is used for the motion compensation, as opposed to ITU-T Rec. H.261 where full pixel precision and a loopfilter are used. Variable length coding is used for the symbols to be transmitted. In addition to the basic video source coding algorithm, eighteen negotiable c
10、oding options are included for improved compression performance and the support of additional capabilities. Additional supplemental information may also be included in the bitstream for enhanced display capability and for external usage. This third edition of H.263 integrates Annexes U, V, W and X,
11、which were approved and published separately before, with a number of corrections and clarifications: correction of Figure 8; clarification in Table 1 regarding BPPmaxKb table and Picture Padding; clarification in clause 5.3.2 regarding macroblock stuffing preceding a start code; clarification regar
12、ding interaction between H.263 Annex J and IDCT rounding error; clarification in Annex N regarding parsability of the GN/MBA field in BCM; clarification in Annex O regarding direct bi-dir predicted MBs and picture extrapolation; clarification on the use of B pictures with intra reference pictures in
13、 Annex O; clarification on the use of Annex P with Annex N; correction of Figure U.7 in Annex U. Source ITU-T Recommendation H.263 was approved on 13 January 2005 by ITU-T Study Group 16 (2005-2008) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. H.263 (01/2005) FOREWORD The Internationa
14、l Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations o
15、n them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of
16、ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is
17、used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with th
18、e Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of
19、 any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Pr
20、operty Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, impl
21、ementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. ITU 2005 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec.
22、 H.263 (01/2005) iii CONTENTS Page 1 Scope 1 2 References. 1 2.1 Normative references 1 2.2 Informative references 1 3 Brief specification. 2 3.1 Video input and output . 2 3.2 Digital output and input 2 3.3 Sampling frequency 2 3.4 Source coding algorithm. 2 3.5 Bit rate 5 3.6 Buffering. 6 3.7 Symm
23、etry of transmission 6 3.8 Error handling. 6 3.9 Multipoint operation. 6 4 Source coder . 7 4.1 Source format . 7 4.2 Video source coding algorithm 9 4.3 Coding control 13 4.4 Forced updating 13 4.5 Byte alignment of start codes . 13 5 Syntax and semantics 13 5.1 Picture layer 22 5.2 Group of Blocks
24、 Layer . 32 5.3 Macroblock layer 33 5.4 Block layer 40 6 Decoding process 44 6.1 Motion compensation . 44 6.2 Coefficients decoding. 46 6.3 Reconstruction of blocks 48 Annex A Inverse transform accuracy specification 48 Annex B Hypothetical Reference Decoder. 49 Annex C Considerations for multipoint
25、 51 C.1 Freeze picture request. 51 C.2 Fast update request . 51 C.3 Freeze picture release . 51 C.4 Continuous Presence Multipoint and Video Multiplexing (CPM). 51 iv ITU-T Rec. H.263 (01/2005) Annex D Unrestricted Motion Vector mode. 53 D.1 Motion vectors over picture boundaries. 53 D.2 Extension o
26、f the motion vector range. 54 Annex E Syntax-based Arithmetic Coding mode. 56 E.1 Introduction 56 E.2 Specification of SAC encoder 57 E.3 Specification of SAC decoder 58 E.4 Syntax. 58 E.5 PSC_FIFO 59 E.6 Header layer symbols . 59 E.7 Macroblock and Block layer symbols 60 E.8 SAC models 60 Annex F A
27、dvanced Prediction mode 64 F.1 Introduction 64 F.2 Four motion vectors per macroblock 64 F.3 Overlapped motion compensation for luminance. 65 Annex G PB-frames mode 68 G.1 Introduction 68 G.2 PB-frames and INTRA blocks 68 G.3 Block layer 68 G.4 Calculation of vectors for the B-picture in a PB-frame
28、69 G.5 Prediction of a B-block in a PB-frame . 69 Annex H Forward error correction for coded video signal. 71 H.1 Introduction 71 H.2 Error correction framing. 71 H.3 Error correcting code 71 H.4 Relock time for error corrector framing . 72 Annex I Advanced INTRA Coding mode. 72 I.1 Introduction 72
29、I.2 Syntax. 73 I.3 Decoding process 74 Annex J Deblocking Filter mode 80 J.1 Introduction 80 J.2 Relation to UMV and AP modes (Annexes D and F) 81 J.3 Definition of the deblocking edge filter . 81 Annex K Slice Structured mode . 85 K.1 Introduction 85 K.2 Structure of slice layer 86 ITU-T Rec. H.263
30、 (01/2005) v Annex L Supplemental enhancement information specification 88 L.1 Introduction 88 L.2 PSUPP format. 88 L.3 Do Nothing . 89 L.4 Full-Picture Freeze Request . 89 L.5 Partial-Picture Freeze Request . 89 L.6 Resizing Partial-Picture Freeze Request 90 L.7 Partial-Picture Freeze-Release Reque
31、st 90 L.8 Full-Picture Snapshot Tag 90 L.9 Partial-Picture Snapshot Tag 91 L.10 Video Time Segment Start Tag 91 L.11 Video Time Segment End Tag . 91 L.12 Progressive Refinement Segment Start Tag. 91 L.13 Progressive Refinement Segment End Tag 91 L.14 Chroma Keying Information 92 L.15 Extended Functi
32、on Type. 94 Annex M Improved PB-frames mode. 94 M.1 Introduction 94 M.2 BPB-macroblock prediction modes . 95 M.3 Calculation of vectors for bidirectional prediction of a the B-macroblock 95 M.4 MODB table . 95 Annex N Reference Picture Selection mode. 96 N.1 Introduction 96 N.2 Video source coding a
33、lgorithm 97 N.3 Channel for back-channel messages. 97 N.4 Syntax. 98 N.5 Decoder process 101 Annex O Temporal, SNR, and Spatial Scalability mode 102 O.1 Overview 102 O.2 Transmission order of pictures . 106 O.3 Picture layer syntax 107 O.4 Macroblock layer syntax 108 O.5 Motion vector decoding 112 O
34、.6 Interpolation filters . 112 Annex P Reference picture resampling. 115 P.1 Introduction 115 P.2 Syntax. 118 P.3 Resampling algorithm 120 P.4 Example of implementation . 123 P.5 Factor-of-4 resampling . 126 vi ITU-T Rec. H.263 (01/2005) Annex Q Reduced-Resolution Update mode 130 Q.1 Introduction 13
35、0 Q.2 Decoding procedure 131 Q.3 Extension of referenced picture 133 Q.4 Reconstruction of motion vectors. 134 Q.5 Enlarged overlapped motion compensation for luminance 136 Q.6 Upsampling of the reduced-resolution reconstructed prediction error. 138 Q.7 Block boundary filter 141 Annex R Independent
36、Segment Decoding mode 143 R.1 Introduction 143 R.2 Mode operation. 143 R.3 Constraints on usage. 144 Annex S Alternative INTER VLC mode 145 S.1 Introduction 145 S.2 Alternative INTER VLC for coefficients. 145 S.3 Alternative INTER VLC for CBPY . 146 Annex T Modified Quantization mode . 146 T.1 Intro
37、duction 146 T.2 Modified DQUANT Update. 146 T.3 Altered quantization step size for chrominance coefficients 147 T.4 Modified coefficient range . 148 T.5 Usage restrictions . 148 Annex U Enhanced reference picture selection mode 149 U.1 Introduction 149 U.2 Video source coding algorithm 150 U.3 Forwa
38、rd-channel syntax . 151 U.4 Decoder process 169 U.5 Back-channel messages 174 Annex V Data-partitioned slice mode. 178 V.1 Scope 178 V.2 Structure of data partitioning 178 V.3 Interaction with other optional modes 181 Annex W Additional supplemental enhancement information specification . 185 W.1 Sc
39、ope 185 W.2 References 185 W.3 Additional FTYPE Values 185 W.4 Recommended maximum number of PSUPP octets 185 W.5 Fixed-point IDCT . 185 W.6 Picture message 195 ITU-T Rec. H.263 (01/2005) vii Annex X Profiles and levels definition. 200 X.1 Scope 200 X.2 Profiles of preferred mode support. 200 X.3 Pi
40、cture formats and picture clock frequencies 204 X.4 Levels of performance capability . 205 X.5 Generic capability definitions for use with ITU-T Rec. H.245 209 Appendix I Error tracking. 213 I.1 Introduction 213 I.2 Error tracking 213 Appendix II Recommended optional enhancement 214 ITU-T Rec. H.263
41、 (01/2005) 1 ITU-T Recommendation H.263 Video coding for low bit rate communication 1 Scope This Recommendation specifies a coded representation that can be used for compressing the moving picture component of audio-visual services at low bit rates. The basic configuration of the video source coding
42、 algorithm is based on ITU-T Rec. H.261. Eighteen negotiable coding options are included for improved performance and increased functionality. This Recommendation contains Version 2 of ITU-T Rec. H.263, which is fully compatible with the original Recommendation, adding only optional features to the
43、original Version 1 content of the Recommendation. 2 References 2.1 Normative references The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated
44、were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recomme
45、ndations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. 1 ITU-R Recommendation BT.601-5 (1995), Studio encoding parameters of digital television for standard 4:3 and wide-screen 16:9 aspect r
46、atios. Reference 1 is referenced herein to define the (Y, CB, CR) colour space and its 8-bit integer representation for pictures used by video codecs designed according to this Recommendation. (Reference 1 is not used to define any other aspects of this Recommendation.) 2.2 Informative references Th
47、e following additional ITU-T Recommendations are mentioned for illustration purposes in this text. 2 ITU-T Recommendation H.223 (2001), Multiplexing protocol for low bit rate multimedia communication. 3 ITU-T Recommendation H.242 (2004), System for establishing communication between audiovisual term
48、inals using digital channels up to 2 Mbit/s. 4 ITU-T Recommendation H.245 (2005), Control protocol for multimedia communication. 5 ITU-T Recommendation H.261 (1993), Video codec for audiovisual services at p 64 kbit/s. 6 ITU-T Recommendation H.262 (2000) | ISO/IEC 13818-2:2000, Information technolog
49、y Generic coding of moving pictures and associated audio information: Video. 7 ITU-T Recommendation H.324 (2002), Terminal for low bit-rate multimedia communication. 2 ITU-T Rec. H.263 (01/2005) 3 Brief specification An outline block diagram of the codec is given in Figure 1. T1602680-97Video multiplexcoderCoding controlb) Video decoderExternal controlTransmissionbufferCodedbitstreamVideosignalSourcedecoderVideo multiplexdecoderReceivingbufferSourcecodera) Video coderFigure 1/H.2
