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 01 23 45 67 89 1011 1213 1415 1617 1819 2021 2223 2425 2627 2829 3031 3233 3435 3637 3839 4041 4243 4445 4647 4849 5051 5253 5455 5657 5859 6061 6263 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 LCU (e.g. 64x64, z-scan) 01 89 23 1011 1617 2425 1819 2627 45 1213 67 1415 2021 2829 2223 3031 3233 4041 3435 4243 4849 5657 5051 5859 3637 4445 3839 4647 5253 6061 5455 6263 LCU (e.g. 64x64, raster) g_auiZscanToRaster g_auiRasterToZscan 01 23 45 67 89 1011 1213 1415 1617 1819 2021 2223 2425 2627 2829 3031 3233 3435 3637 3839 4041 4243 4445 4647 4849 5051 5253 5455 5657 5859 6061 6263

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