L0293_CPR mode

cfg/encoder_intra_vtm.cfg

@@ -111,6 +111,7 @@ LMChroma                     : 1      # use CCLM only
 DepQuant                     : 1
 IMV                          : 2
 ALF                          : 1
+CPR                          : 0      # turned off in CTC 
 
 # Fast tools
 PBIntraFast                  : 1

cfg/encoder_lowdelay_P_vtm.cfg

@@ -128,6 +128,7 @@ DepQuant                     : 1
 IMV                          : 2
 ALF                          : 1
 MHIntra                      : 1
+CPR                          : 0      # turned off in CTC
 
 # Fast tools
 PBIntraFast                  : 1

cfg/encoder_lowdelay_vtm.cfg

@@ -131,6 +131,7 @@ GBi                          : 1
 GBiFast                      : 1 
 MHIntra                      : 1
 Triangle                     : 1
+CPR                          : 0      # turned off in CTC
 
 # Fast tools
 PBIntraFast                  : 1

cfg/encoder_randomaccess_vtm.cfg

@@ -146,6 +146,7 @@ GBiFast                      : 1
 BIO                          : 1 
 MHIntra                      : 1
 Triangle                     : 1
+CPR                          : 0      # turned off in CTC
 
 # Fast tools
 PBIntraFast                  : 1

source/App/EncoderApp/EncApp.cpp

@@ -269,6 +269,17 @@ void EncApp::xInitLibCfg()
 #if JVET_L0124_L0208_TRIANGLE
   m_cEncLib.setUseTriangle                                       ( m_Triangle );
 #endif
+
+#if JVET_L0293_CPR
+  m_cEncLib.setCPRMode                                           ( m_CPRMode );
+  m_cEncLib.setCPRLocalSearchRangeX                              ( m_CPRLocalSearchRangeX );
+  m_cEncLib.setCPRLocalSearchRangeY                              ( m_CPRLocalSearchRangeY );
+  m_cEncLib.setCPRHashSearch                                     ( m_CPRHashSearch );
+  m_cEncLib.setCPRHashSearchMaxCand                              ( m_CPRHashSearchMaxCand );
+  m_cEncLib.setCPRHashSearchRange4SmallBlk                       ( m_CPRHashSearchRange4SmallBlk );
+  m_cEncLib.setCPRFastMethod                                     ( m_CPRFastMethod );
+#endif    
+
   // ADD_NEW_TOOL : (encoder app) add setting of tool enabling flags and associated parameters here
 
   m_cEncLib.setMaxCUWidth                                        ( m_QTBT ? m_uiCTUSize : m_uiMaxCUWidth );

source/App/EncoderApp/EncAppCfg.cpp

@@ -874,6 +874,17 @@ bool EncAppCfg::parseCfg( int argc, char* argv[] )
 #if JVET_L0124_L0208_TRIANGLE
   ("Triangle",                                        m_Triangle,                                       false, "Enable triangular shape motion vector prediction (0:off, 1:on)")
 #endif
+
+#if JVET_L0293_CPR
+  ( "CPR",                                            m_CPRMode,                                           0u, "CPRMode (0x1:enabled, 0x0:disabled)  [default: disabled]")
+  ( "CPRLocalSearchRangeX",                           m_CPRLocalSearchRangeX,                            128u, "Search range of CPR local search in x direction")
+  ( "CPRLocalSearchRangeY",                           m_CPRLocalSearchRangeY,                            128u, "Search range of CPR local search in y direction")
+  ( "CPRHashSearch",                                  m_CPRHashSearch,                                     1u, "Hash based CPR search")
+  ( "CPRHashSearchMaxCand",                           m_CPRHashSearchMaxCand,                            256u, "Max candidates for hash based CPR search")
+  ( "CPRHashSearchRange4SmallBlk",                    m_CPRHashSearchRange4SmallBlk,                     256u, "Small block search range in based CPR search")
+  ( "CPRFastMethod",                                  m_CPRFastMethod,                                     6u, "Fast methods for CPR")
+#endif
+
   // ADD_NEW_TOOL : (encoder app) add parsing parameters here
 
   ("LCTUFast",                                        m_useFastLCTU,                                    false, "Fast methods for large CTU")
@@ -1964,6 +1975,9 @@ bool EncAppCfg::xCheckParameter()
     xConfirmPara( m_DisableMotionCompression, "Disable motion data compression only allowed with NEXT profile" );
     xConfirmPara( m_MTT, "Multi type tree is only allowed with NEXT profile" );
     xConfirmPara( m_ImvMode, "IMV is only allowed with NEXT profile" );
+#if JVET_L0293_CPR
+    xConfirmPara(m_CPRMode, "CPR Mode only allowed with NEXT profile");
+#endif
     xConfirmPara( m_useFastLCTU, "Fast large CTU can only be applied when encoding with NEXT profile" );
     xConfirmPara( m_EMT, "EMT only allowed with NEXT profile" );
     xConfirmPara( m_FastEMT, "EMT only allowed with NEXT profile" );
@@ -3208,6 +3222,9 @@ void EncAppCfg::xPrintParameter()
     msg( VERBOSE, "Triangle:%d ", m_Triangle );
 #endif
   }
+#if JVET_L0293_CPR
+    msg(VERBOSE, "CPR:%d ", m_CPRMode);
+#endif
   // ADD_NEW_TOOL (add some output indicating the usage of tools)
 
   msg( VERBOSE, "\nFAST TOOL CFG: " );

source/App/EncoderApp/EncAppCfg.h

@@ -246,6 +246,18 @@ protected:
 #if JVET_L0124_L0208_TRIANGLE
   bool      m_Triangle;
 #endif
+
+
+#if JVET_L0293_CPR
+  unsigned  m_CPRMode;
+  unsigned  m_CPRLocalSearchRangeX;
+  unsigned  m_CPRLocalSearchRangeY;
+  unsigned  m_CPRHashSearch;
+  unsigned  m_CPRHashSearchMaxCand;
+  unsigned  m_CPRHashSearchRange4SmallBlk;
+  unsigned  m_CPRFastMethod;
+#endif    
+  
   // ADD_NEW_TOOL : (encoder app) add tool enabling flags and associated parameters here
 
   unsigned  m_uiMaxCUWidth;                                   ///< max. CU width in pixel

source/Lib/CommonLib/CodingStructure.cpp

@@ -749,7 +749,11 @@ void CodingStructure::useSubStructure( const CodingStructure& subStruct, const C
   if( cpyResi ) picture->getResiBuf( clippedArea ).copyFrom( subResiBuf );
   if( cpyReco ) picture->getRecoBuf( clippedArea ).copyFrom( subRecoBuf );
 
+#if JVET_L0293_CPR
+  if (!subStruct.m_isTuEnc && (!slice->isIntra() && subStruct.chType != CHANNEL_TYPE_CHROMA))
+#else
   if( !subStruct.m_isTuEnc && !slice->isIntra() )
+#endif
   {
     // copy motion buffer
     MotionBuf ownMB  = getMotionBuf          ( clippedArea );
@@ -1302,3 +1306,38 @@ const TransformUnit* CodingStructure::getTURestricted( const Position &pos, cons
   }
 }
 
+#if JVET_L0293_CPR 
+CprLumaCoverage CodingStructure::getCprLumaCoverage(const CompArea& chromaArea) const
+{
+  CHECK(chType != CHANNEL_TYPE_CHROMA, "Error");
+
+  const unsigned int unitAreaSubBlock = MIN_PU_SIZE * MIN_PU_SIZE;
+  CompArea lumaArea = CompArea(COMPONENT_Y, chromaArea.chromaFormat, chromaArea.lumaPos(), recalcSize(chromaArea.chromaFormat, CHANNEL_TYPE_CHROMA, CHANNEL_TYPE_LUMA, chromaArea.size()));
+  lumaArea = clipArea(lumaArea, picture->block(COMPONENT_Y));
+  const unsigned int fullArea = lumaArea.area();
+  unsigned int cprArea = 0;
+  for (SizeType y = 0; y < lumaArea.height; y += MIN_PU_SIZE)
+  {
+    for (SizeType x = 0; x < lumaArea.width; x += MIN_PU_SIZE)
+    {
+      Position pos = lumaArea.offset(x, y);
+      if (picture->cs->getMotionInfo(pos).isInter) // need to change if inter slice allows dualtree
+      {
+        cprArea += unitAreaSubBlock;
+      }
+    }
+  }
+
+  CprLumaCoverage coverage = CPR_LUMA_COVERAGE_FULL;
+  if (cprArea == 0)
+  {
+    coverage = CPR_LUMA_COVERAGE_NONE;
+  }
+  else if (cprArea < fullArea)
+  {
+    coverage = CPR_LUMA_COVERAGE_PARTIAL;
+  }
+
+  return coverage;
+}
+#endif
\ No newline at end of file

source/Lib/CommonLib/CodingStructure.h

@@ -58,6 +58,15 @@ enum PictureType
   PIC_ORG_RESI,
   NUM_PIC_TYPES
 };
+#if JVET_L0293_CPR
+enum CprLumaCoverage
+{
+  CPR_LUMA_COVERAGE_FULL = 0,
+  CPR_LUMA_COVERAGE_PARTIAL,
+  CPR_LUMA_COVERAGE_NONE,
+  NUM_CPR_LUMA_COVERAGE,
+};
+#endif
 extern XUCache g_globalUnitCache;
 
 // ---------------------------------------------------------------------------
@@ -76,6 +85,9 @@ public:
   Slice           *slice;
 
   UnitScale        unitScale[MAX_NUM_COMPONENT];
+#if JVET_L0293_CPR
+  ChannelType chType;
+#endif
 
   int         baseQP;
   int         prevQP[MAX_NUM_CHANNEL_TYPE];
@@ -146,6 +158,9 @@ public:
   cCUTraverser    traverseCUs(const UnitArea& _unit, const ChannelType _chType) const;
   cPUTraverser    traversePUs(const UnitArea& _unit, const ChannelType _chType) const;
   cTUTraverser    traverseTUs(const UnitArea& _unit, const ChannelType _chType) const;
+#if JVET_L0293_CPR
+  CprLumaCoverage getCprLumaCoverage(const CompArea& chromaArea) const;
+#endif
   // ---------------------------------------------------------------------------
   // encoding search utilities
   // ---------------------------------------------------------------------------

source/Lib/CommonLib/Common.h

@@ -114,6 +114,28 @@ struct UnitScale
   Size     scale( const Size     &size ) const { return { size.width >> posx, size.height >> posy }; }
   Area     scale( const Area    &_area ) const { return Area( scale( _area.pos() ), scale( _area.size() ) ); }
 };
+#if JVET_L0293_CPR
+namespace std
+{
+  template <>
+  struct hash<Position> : public unary_function<Position, uint64_t>
+  {
+    uint64_t operator()(const Position& value) const
+    {
+      return (((uint64_t)value.x << 32) + value.y);
+    }
+  };
+
+  template <>
+  struct hash<Size> : public unary_function<Size, uint64_t>
+  {
+    uint64_t operator()(const Size& value) const
+    {
+      return (((uint64_t)value.width << 32) + value.height);
+    }
+  };
+}
+#endif
 inline size_t rsAddr(const Position &pos, const uint32_t stride, const UnitScale &unitScale )
 {
   return (size_t)(stride >> unitScale.posx) * (size_t)(pos.y >> unitScale.posy) + (size_t)(pos.x >> unitScale.posx);

source/Lib/CommonLib/CommonDef.h

@@ -435,6 +435,15 @@ static const int TRIANGLE_MAX_NUM_SATD_CANDS =                      3;
 static const int TRIANGLE_MIN_SIZE =                            8 * 8;
 #endif
 
+#if JVET_L0293_CPR
+static const int CPR_MAX_CAND_SIZE = 16; // max block size for cpr search
+static const int CPR_NUM_CANDIDATES = 64; ///< Maximum number of candidates to store/test
+static const int CHROMA_REFINEMENT_CANDIDATES = 8; /// 8 candidates BV to choose from
+static const int CPR_FAST_METHOD_NOINTRA_CPRCBF0 = 0x01;
+static const int CPR_FAST_METHOD_BUFFERBV = 0X02;
+static const int CPR_FAST_METHOD_ADAPTIVE_SEARCHRANGE = 0X04;
+#endif
+
 // ====================================================================================================================
 // Macro functions
 // ====================================================================================================================

source/Lib/CommonLib/ContextModelling.cpp

@@ -397,7 +397,14 @@ void MergeCtx::setMergeInfo( PredictionUnit& pu, int candIdx )
   pu.mvpIdx [REF_PIC_LIST_1] = NOT_VALID;
   pu.mvpNum [REF_PIC_LIST_0] = NOT_VALID;
   pu.mvpNum [REF_PIC_LIST_1] = NOT_VALID;
-
+#if JVET_L0293_CPR
+  if (interDirNeighbours[candIdx] == 1 && pu.cs->slice->getRefPic(REF_PIC_LIST_0, mvFieldNeighbours[candIdx << 1].refIdx)->getPOC() == pu.cs->slice->getPOC())
+  {
+    pu.cu->cpr = true;
+    pu.bv = pu.mv[REF_PIC_LIST_0];
+    pu.bv >>= (2 + VCEG_AZ07_MV_ADD_PRECISION_BIT_FOR_STORE); // used for only integer resolution
+  }
+#endif
 #if JVET_L0646_GBI 
   pu.cu->GBiIdx = ( interDirNeighbours[candIdx] == 3 ) ? GBiIdx[candIdx] : GBI_DEFAULT;
 #endif

source/Lib/CommonLib/CprHashMap.cpp

+/* The copyright in this software is being made available under the BSD
+ * License, included below. This software may be subject to other third party
+ * and contributor rights, including patent rights, and no such rights are
+ * granted under this license.
+ *
+ * Copyright (c) 2010-2018, ITU/ISO/IEC
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *  * Neither the name of the ITU/ISO/IEC nor the names of its contributors may
+ *    be used to endorse or promote products derived from this software without
+ *    specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** \file     CprHashMap.cpp
+    \brief    CPR hash map encoder class
+*/
+
+#include "CommonLib/dtrace_codingstruct.h"
+#include "CommonLib/Picture.h"
+#include "CommonLib/UnitTools.h"
+#include "CprHashMap.h"
+
+
+using namespace std;
+
+//! \ingroup CprHashMap
+//! \{
+
+// ====================================================================================================================
+// Constructor / destructor / create / destroy
+// ====================================================================================================================
+
+CprHashMap::CprHashMap()
+{
+  m_picWidth = 0;
+  m_picHeight = 0;
+  m_pos2Hash = NULL;
+  m_computeCrc32c = xxComputeCrc32c16bit;
+
+#if ENABLE_SIMD_OPT_CPR
+#ifdef TARGET_SIMD_X86
+  initCprHashMapX86();
+#endif
+#endif
+
+}
+
+CprHashMap::~CprHashMap()
+{
+  destroy();
+}
+
+void CprHashMap::init(const int picWidth, const int picHeight)
+{
+  if (picWidth != m_picWidth || picHeight != m_picHeight)
+  {
+    destroy();
+  }
+
+  m_picWidth = picWidth;
+  m_picHeight = picHeight;
+  m_pos2Hash = new unsigned int*[m_picHeight];
+  m_pos2Hash[0] = new unsigned int[m_picWidth * m_picHeight];
+  for (int n = 1; n < m_picHeight; n++)
+  {
+    m_pos2Hash[n] = m_pos2Hash[n - 1] + m_picWidth;
+  }
+}
+
+void CprHashMap::destroy()
+{
+  if (m_pos2Hash != NULL)
+  {
+    if (m_pos2Hash[0] != NULL)
+    {
+      delete[] m_pos2Hash[0];
+    }
+    delete[] m_pos2Hash;
+  }
+  m_pos2Hash = NULL;
+}
+////////////////////////////////////////////////////////
+// CRC32C calculation in C code, same results as SSE 4.2's implementation
+static const uint32_t crc32Table[256] = {
+  0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L,
+  0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
+  0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL,
+  0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
+  0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL,
+  0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
+  0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L,
+  0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
+  0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL,
+  0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
+  0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L,
+  0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
+  0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L,
+  0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
+  0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL,
+  0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
+  0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L,
+  0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
+  0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L,
+  0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
+  0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L,
+  0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
+  0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L,
+  0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
+  0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L,
+  0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
+  0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L,
+  0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
+  0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L,
+  0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
+  0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L,
+  0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
+  0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL,
+  0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
+  0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L,
+  0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
+  0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L,
+  0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
+  0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL,
+  0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
+  0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L,
+  0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
+  0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL,
+  0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
+  0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL,
+  0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
+  0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L,
+  0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
+  0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L,
+  0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
+  0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL,
+  0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
+  0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL,
+  0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
+  0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L,
+  0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
+  0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL,
+  0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
+  0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L,
+  0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
+  0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L,
+  0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
+  0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL,
+  0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L
+};
+
+uint32_t CprHashMap::xxComputeCrc32c16bit(uint32_t crc, const Pel pel)
+{
+  const void *buf = &pel;
+  const uint8_t *p = (const uint8_t *)buf;
+  size_t size = 2;
+
+  while (size--)
+  {
+    crc = crc32Table[(crc ^ *p++) & 0xff] ^ (crc >> 8);
+  }
+
+  return crc;
+}
+// CRC calculation in C code
+////////////////////////////////////////////////////////
+
+unsigned int CprHashMap::xxCalcBlockHash(const Pel* pel, const int stride, const int width, const int height, unsigned int crc)
+{
+  for (int y = 0; y < height; y++)
+  {
+    for (int x = 0; x < width; x++)
+    {
+      crc = m_computeCrc32c(crc, pel[x]);
+    }
+    pel += stride;
+  }
+  return crc;
+}
+
+template<ChromaFormat chromaFormat>
+void CprHashMap::xxBuildPicHashMap(const PelUnitBuf& pic)
+{
+  const int chromaScalingX = getChannelTypeScaleX(CHANNEL_TYPE_CHROMA, chromaFormat);
+  const int chromaScalingY = getChannelTypeScaleY(CHANNEL_TYPE_CHROMA, chromaFormat);
+  const int chromaMinBlkWidth = MIN_PU_SIZE >> chromaScalingX;
+  const int chromaMinBlkHeight = MIN_PU_SIZE >> chromaScalingY;
+  const Pel* pelY = NULL;
+  const Pel* pelCb = NULL;
+  const Pel* pelCr = NULL;
+
+  Position pos;
+  for (pos.y = 0; pos.y + MIN_PU_SIZE <= pic.Y().height; pos.y++)
+  {
+    // row pointer
+    pelY = pic.Y().bufAt(0, pos.y);
+    if (chromaFormat != CHROMA_400)
+    {
+      int chromaY = pos.y >> chromaScalingY;
+      pelCb = pic.Cb().bufAt(0, chromaY);
+      pelCr = pic.Cr().bufAt(0, chromaY);
+    }
+
+    for (pos.x = 0; pos.x + MIN_PU_SIZE <= pic.Y().width; pos.x++)
+    {
+      // 0x1FF is just an initial value
+      unsigned int hashValue = 0x1FF;
+
+      // luma part
+      hashValue = xxCalcBlockHash(&pelY[pos.x], pic.Y().stride, MIN_PU_SIZE, MIN_PU_SIZE, hashValue);
+
+      // chroma part
+      if (chromaFormat != CHROMA_400)
+      {
+        int chromaX = pos.x >> chromaScalingX;
+        hashValue = xxCalcBlockHash(&pelCb[chromaX], pic.Cb().stride, chromaMinBlkWidth, chromaMinBlkHeight, hashValue);
+        hashValue = xxCalcBlockHash(&pelCr[chromaX], pic.Cr().stride, chromaMinBlkWidth, chromaMinBlkHeight, hashValue);
+      }
+
+      // hash table
+      m_hash2Pos[hashValue].push_back(pos);
+      m_pos2Hash[pos.y][pos.x] = hashValue;
+    }
+  }
+}
+
+void CprHashMap::rebuildPicHashMap(const PelUnitBuf& pic)
+{
+  m_hash2Pos.clear();
+
+  switch (pic.chromaFormat)
+  {
+  case CHROMA_400:
+    xxBuildPicHashMap<CHROMA_400>(pic);
+    break;
+  case CHROMA_420:
+    xxBuildPicHashMap<CHROMA_420>(pic);
+    break;
+  case CHROMA_422:
+    xxBuildPicHashMap<CHROMA_422>(pic);
+    break;
+  case CHROMA_444:
+    xxBuildPicHashMap<CHROMA_444>(pic);
+    break;
+  default:
+    THROW("invalid chroma fomat");
+    break;
+  }
+}
+
+bool CprHashMap::cprHashMatch(const Area& lumaArea, std::vector<Position>& cand, const CodingStructure& cs, const int maxCand, const int searchRange4SmallBlk)
+{
+  cand.clear();
+
+  // find the block with least candidates
+  size_t minSize = MAX_UINT;
+  unsigned int targetHashOneBlock = 0;
+  for (SizeType y = 0; y < lumaArea.height && minSize > 1; y += MIN_PU_SIZE)
+  {
+    for (SizeType x = 0; x < lumaArea.width && minSize > 1; x += MIN_PU_SIZE)
+    {
+      unsigned int hash = m_pos2Hash[lumaArea.pos().y + y][lumaArea.pos().x + x];
+      if (m_hash2Pos[hash].size() < minSize)
+      {
+        minSize = m_hash2Pos[hash].size();
+        targetHashOneBlock = hash;
+      }
+    }
+  }
+
+  if (m_hash2Pos[targetHashOneBlock].size() > 1)
+  {
+    std::vector<Position>& candOneBlock = m_hash2Pos[targetHashOneBlock];
+
+    // check whether whole block match
+    for (std::vector<Position>::iterator refBlockPos = candOneBlock.begin(); refBlockPos != candOneBlock.end(); refBlockPos++)
+    {
+      Position bottomRight = refBlockPos->offset(lumaArea.width - 1, lumaArea.height - 1);
+      bool wholeBlockMatch = true;
+      if (lumaArea.width > MIN_PU_SIZE || lumaArea.height > MIN_PU_SIZE)
+      {
+#if JVET_L0293_CPR
+        if (!cs.isDecomp(bottomRight, cs.chType) || bottomRight.x >= m_picWidth || bottomRight.y >= m_picHeight)
+#else
+        if (!cs.isDecomp(bottomRight, CHANNEL_TYPE_LUMA) || bottomRight.x >= m_picWidth || bottomRight.y >= m_picHeight)
+#endif
+        {
+          continue;
+        }
+        for (SizeType y = 0; y < lumaArea.height && wholeBlockMatch; y += MIN_PU_SIZE)
+        {
+          for (SizeType x = 0; x < lumaArea.width && wholeBlockMatch; x += MIN_PU_SIZE)
+          {
+            // whether the reference block and current block has the same hash
+            wholeBlockMatch &= (m_pos2Hash[lumaArea.pos().y + y][lumaArea.pos().x + x] == m_pos2Hash[refBlockPos->y + y][refBlockPos->x + x]);
+          }
+        }
+      }
+      else
+      {
+#if JVET_L0293_CPR
+        if (abs(refBlockPos->x - lumaArea.x) > searchRange4SmallBlk || abs(refBlockPos->y - lumaArea.y) > searchRange4SmallBlk || !cs.isDecomp(bottomRight, cs.chType))
+#else
+        if (abs(refBlockPos->x -