1.  Samsung Electronics Co. Ltd. and British Broadcasting Corporation, 2010 Data structure and access method (1) LCU vs. Sub-CU –All CUs are handled through TComDataCU* pointer –From the LCU (largest CU), Sub-CU is processed recursively by z-scan 0 1 2 34 56 78 9 1011 1213 14 15 LCU (e.g. 64x64) Sub-CU: TComDataCU* Processing order

2.  Samsung Electronics Co. Ltd. and British Broadcasting Corporation, 2010 Data structure and access method (2) TComDataCU class has all information we need –Actual data storage is allocated only at LCU (largest CU) level In Sub-CUs, data storage points to suitable position in LCU storage LCU (e.g. 64x64) 4 Basic unit for storage

3.  Samsung Electronics Co. Ltd. and British Broadcasting Corporation, 2010 Data structure and access method (3) Every information in CU is accessed by index –Basically, every index is the storage unit number within the CU –In source-code, AbsPartIdx means absolute index in the given CU LCU (e.g. 64x64) Index in CU 01 23 45 67 89 1011 1213 1415 Sub-CU: TComDataCU* pcCU pcCU->getPredictionMode(0) Basic unit for storage

4.  Samsung Electronics Co. Ltd. and British Broadcasting Corporation, 2010 Data structure and access method (4) How to obtain absolute index in LCU? –Each TComDataCU class has m_uiAbsIdxInLCU, which means the absolute z-scan index in LCU basis –Useful to derive index of neighbouring CUs 12 34 56 78 910 1112 1314 1516 1718 1920 2122 2324 2526 2930 2728 3132 3334 3536 3738 3940 4142 4344 4546 4748 4950 5152 5354 5556 5758 5960 6162 6364 LCU (e.g. 64x64) Sub-CU: TComDataCU* pcCU pcCU->m_uiAbsIdxInLCU

5.  Samsung Electronics Co. Ltd. and British Broadcasting Corporation, 2010 Data structure and access method (5) How to convert between z-scan and raster scan in LCU-based index? –Two arrays, g_auiZscanToRaster and g_auiRasterToZscan –g_auiZscanToRaster[ z-scan index ] = raster scan index –g_auiRasterToZscan[ raster index ] = z-scan index –Raster scan is useful to derive index of neighbouring CUs 12 34 56 78 910 1112 1314 1516 1718 1920 2122 2324 2526 2930 2728 3132 3334 3536 3738 3940 4142 4344 4546 4748 4950 5152 5354 5556 5758 5960 6162 6364 LCU (e.g. 64x64, z-scan) 12 910 34 1112 1718 2526 1920 2728 56 1314 78 1516 2122 2930 2324 3132 3334 4142 3536 4344 4950 5758 5152 5960 3738 4546 3940 4748 5354 6162 5556 6364 LCU (e.g. 64x64, raster) g_auiZscanToRaster g_auiRasterToZscan

6.  Samsung Electronics Co. Ltd. and British Broadcasting Corporation, 2010 Data structure and access method (6) Transform coefficient data structure –1D arrays, m_pcTrCoeffY, m_pcTrCoeffCb and m_pcTrCoeffCr are allocated in LCU –For each CU, getCoeffY, getCoeffCb and getCoeffCr give the starting point of coefficients. They are arranged using raster-scan 0 1 2 34 LCU (e.g. 64x64) 16 LCU, m_pcTrCoeffY (64x64 = 4096 entries) Sub-CU: TComDataCU* pcCU pcCU->getCoeffY() 16x16 = 256 entries