Rec. UIT-T H.263 – VIDEO CODING FOR LOW BIT RATE COMMUNICATION
FOREWORD
CONTENTS
SUMMARY
1 Scope
2 References
3 Brief specification
    3.1 Video input and output
    3.2 Digital output and input
    3.3 Sampling frequency
    3.4 Source coding algorithm
    3.5 Bit rate
    3.6 Buffering
    3.7 Symmetry of transmission
    3.8 Error handling
    3.9 Multipoint operation
4 Source coder
    4.1 Source format
    4.2 Video source coding algorithm
    4.3 Coding control
    4.4 Forced updating
    4.5 Byte alignment of start codes
5 Syntax and semantics
    5.1 Picture layer
    5.2 Group of Blocks Layer
    5.3 Macroblock Layer
    5.4 Block Layer
6 Decoding process
    6.1 Motion compensation
    6.2 Coefficients decoding
    6.3 Reconstruction of blocks
Annex A – Inverse transform accuracy specification
Annex B – Hypothetical Reference Decoder
Annex C – Considerations for Multipoint
C.1 Freeze picture request
C.2 Fast update request
C.3 Freeze picture release
C.4 Continuous Presence Multipoint (CPM) (not used for Recommendation H.324)
Annex D – Unrestricted Motion Vector mode
D.1 Motion vectors over picture boundaries
D.2 Extension of the motion vector range
Annex E – Syntax-based Arithmetic Coding mode
E.1 Introduction
E.2 Specification of SAC encoder
E.3 Specification of SAC decoder
E.4 Syntax
E.5 PSC_FIFO
E.6 Fixed length symbols
E.7 Non-fixed length symbols
E.8 SAC Models
Annex F – Advanced Prediction mode
F.1 Introduction
F.2 Four motion vectors per macroblock
F.3 Overlapped motion compensation for luminance
Annex G – PB-frames mode
G.1 Introduction
G.2 PB-frames and INTRA blocks
G.3 Block Layer
G.4 Calculation of vectors for the B-picture in a PB-frame
G.5 Prediction of a B-block in a PB-frame
Annex H – Forward Error Correction for coded video signal
H.1 Introduction
H.2 Error correction framing
H.3 Error correcting code
H.4 Relock time for error corrector framing