STUDY OF ISO/IEC 14496-10 and ISO/IEC 14496-5 / AMD6
3.1.2.1.5 Finding the Best Prediction Direction for B slice.................................................................7
3.1.2.2 The Algorithmic Steps to Encode a Macroblock 8
3.1.2.2.1 Determining the Best Combination of Intra Modes..............................................................8
3.1.2.2.1.1 Selecting the Best Intra4x4 Prediction Mode 8
3.1.2.2.1.2 Selecting the best Intra16x16 Prediction Mode 8
3.1.2.2.1.3 Lagrangian Cost for Intra Chroma Mode 9
3.1.2.2.1.4 Lagrangian Cost for Intra Mode 9
3.1.2.2.2 Determining the Best Inter Modes for each sub macroblock..............................................9
3.1.2.2.3 Selecting the Best Inter Mode..............................................................................................10
3.1.2.2.4 Final Macroblock Prediction Mode Decision......................................................................10
3.1.3 Fast High-complexity mode........................................................................................................11
3.1.3.1 Fast Motion Estimation 11
3.1.3.1.1 Motion prediction set for fast search...................................................................................13
3.1.3.1.2 Early_termination.................................................................................................................. 14
3.1.3.1.2.1 Cost Prediction of the Current Paritition 14
3.1.3.1.2.2 Early termination 15
3.1.3.2 Fast Fractional Pel Motion Estimation 16
3.1.3.3 For interlace frame and B frame cases 17
3.1.3.4 Fast Intra and Inter Mode Selection 17
3.1.3.4.1 Edge Map Generation............................................................................................................ 18
3.1.3.4.2 Early SKIP mode decision in inter-coded slices.................................................................18
3.1.3.4.3 Fast inter mode decision...................................................................................................... 18
3.1.3.4.3.1 Homogeneous block detection 19
3.1.3.4.3.2 Mode decision for homogeneous and non-homogeneous blocks 19
3.1.3.4.4 Selective intra mode decision..............................................................................................19
3.1.3.4.5 Fast intra mode decision...................................................................................................... 20
3.1.3.4.5.1 44 luma block prediction modes 22
3.1.3.4.5.2 1616 luma block prediction modes 22
3.1.3.4.5.3 88 chroma prediction modes 22
3.1.4 Low-complexity mode................................................................................................................. 23
3.1.4.1 Prediction Blocks and Computing SA(T)D 23
3.1.4.2 Computing SA(T)D0 23
3.1.4.3 Final Mode Selection by Determining SA(T)D
min
24
3.2 Transform and quantisation.......................................................................................................... 24
3.2.1 Quantisation tables..................................................................................................................... 24
3.2.2 4x4 spatial block processing...................................................................................................... 25
3.2.3 DC luminance coefficients in 16x16 intra mode.......................................................................25
3.2.4 DC chrominance coefficients..................................................................................................... 26
3.3 Elimination of single coefficients in inter macroblocks..............................................................26
3.3.1 Luminance................................................................................................................................... 26
3.3.2 Chrominance............................................................................................................................... 27
3.4 S-Pictures........................................................................................................................................ 27
3.4.1 Encoding of secondary SP-pictures..........................................................................................27
3.4.2 Encoding of SI-pictures.............................................................................................................. 27
3.5 Encoding with anticipation of slice losses..................................................................................27
3.6 Rate Control.................................................................................................................................... 29
3.6.1 GOP level rate control................................................................................................................. 29
3.6.2 Picture level rate control............................................................................................................. 30
3.6.2.1 Pre-encoding stage 31
3.6.2.1.1 Non-stored pictures.............................................................................................................. 31
3.6.2.1.2 Stored pictures...................................................................................................................... 31
3.6.2.2 Post-encoding stage 34
3.6.3 Basic unit level rate control........................................................................................................34
4 Non-normative decoder error concealment description 36
4.1 Introduction.................................................................................................................................... 36
4.2 Intra frame concealment................................................................................................................ 37
4.3 Inter and SP frame concealment...................................................................................................38
4.3.1 General......................................................................................................................................... 38
4.3.2 Concealment using motion vector prediction..........................................................................38
4.3.3 Handling of multiple reference frames......................................................................................39
4.4 B frame concealment..................................................................................................................... 39
4.5 Handling of entire frame losses.................................................................................................... 39
ii STUDY OF ITU-T Rec. H.264 and ITU-T Rec. H.2.64.2
