[x265] revert getSigCtxInc() to 0.7

Satoshi Nakagawa nakagawa424 at oki.com
Mon Mar 10 09:11:29 CET 2014


# HG changeset patch
# User Satoshi Nakagawa <nakagawa424 at oki.com>
# Date 1394438812 -32400
#      Mon Mar 10 17:06:52 2014 +0900
# Node ID d1d80d6baa3fa2db76ec769e461201ae68405f27
# Parent  82a66870fc8b35519cbd7cb4f803740aba98b98b
revert getSigCtxInc() to 0.7

diff -r 82a66870fc8b -r d1d80d6baa3f source/Lib/TLibCommon/TComTrQuant.cpp
--- a/source/Lib/TLibCommon/TComTrQuant.cpp	Sun Mar 09 21:49:30 2014 -0500
+++ b/source/Lib/TLibCommon/TComTrQuant.cpp	Mon Mar 10 17:06:52 2014 +0900
@@ -488,6 +488,7 @@
 {
     //set the group layout
     const uint32_t log2TrSizeCG = log2TrSize - MLS_CG_LOG2_SIZE;
+    result.log2TrSize   = log2TrSize;
     result.log2TrSizeCG = log2TrSizeCG;
 
     //set the scan orders
@@ -497,6 +498,7 @@
 
     //set the significance map context selection parameters
     TextType ctype = ttype == TEXT_LUMA ? TEXT_LUMA : TEXT_CHROMA;
+    result.ctype = ctype;
     if (log2TrSize == 2)
     {
         result.firstSignificanceMapContext = significanceMapContextSetStart[ctype][CONTEXT_TYPE_4x4];
@@ -625,7 +627,7 @@
                 }
                 else
                 {
-                    uint16_t ctxSig = getSigCtxInc(patternSigCtx, codingParameters, scanPos, log2TrSize, ttype);
+                    uint16_t ctxSig = getSigCtxInc(patternSigCtx, codingParameters, blkPos);
                     level           = xGetCodedLevel(costCoeff[scanPos], costCoeff0[scanPos], costSig[scanPos],
                                                      levelDouble, maxAbsLevel, ctxSig, oneCtx, absCtx, goRiceParam,
                                                      c1Idx, c2Idx, qbits, scaleFactor, 0);
@@ -1026,9 +1028,7 @@
  */
 int TComTrQuant::getSigCtxInc(int                              patternSigCtx,
                               const TUEntropyCodingParameters &codingParameters,
-                              const int                        scanPosition,
-                              const int                        log2TrSize,
-                              const TextType                   ttype)
+                              const int                        blkPos)
 {
     static const int ctxIndMap[16] =
     {
@@ -1037,73 +1037,60 @@
         6, 6, 8, 8,
         7, 7, 8, 8
     };
-    const uint32_t rasterPosition = codingParameters.scan[scanPosition];
-    const uint32_t posY           = rasterPosition >> log2TrSize;
-    const uint32_t posX           = rasterPosition - (posY << log2TrSize);
 
-    if ((posX + posY) == 0) return 0; //special case for the DC context variable
+    if (blkPos == 0) return 0; //special case for the DC context variable
 
-    int offset = MAX_INT;
-
+    const int log2TrSize = codingParameters.log2TrSize;
     if (log2TrSize == 2) //4x4
     {
-        offset = ctxIndMap[(4 * posY) + posX];
+        return ctxIndMap[blkPos];
     }
-    else
+
+    const uint32_t posY           = blkPos >> log2TrSize;
+    const uint32_t posX           = blkPos - (posY << log2TrSize);
+
+    int posXinSubset = posX & 3;
+    int posYinSubset = posY & 3;
+
+    // NOTE: [patternSigCtx][posXinSubset][posYinSubset]
+    static const uint8_t table_cnt[4][4][4] =
     {
-        int cnt = 0;
+        // patternSigCtx = 0
+        {
+            { 2, 1, 1, 0 },
+            { 1, 1, 0, 0 },
+            { 1, 0, 0, 0 },
+            { 0, 0, 0, 0 },
+        },
+        // patternSigCtx = 1
+        {
+            { 2, 1, 0, 0 },
+            { 2, 1, 0, 0 },
+            { 2, 1, 0, 0 },
+            { 2, 1, 0, 0 },
+        },
+        // patternSigCtx = 2
+        {
+            { 2, 2, 2, 2 },
+            { 1, 1, 1, 1 },
+            { 0, 0, 0, 0 },
+            { 0, 0, 0, 0 },
+        },
+        // patternSigCtx = 3
+        {
+            { 2, 2, 2, 2 },
+            { 2, 2, 2, 2 },
+            { 2, 2, 2, 2 },
+            { 2, 2, 2, 2 },
+        }
+    };
 
-        switch (patternSigCtx)
-        {
-        case 0: //neither neighbouring group is significant
-        {
-            const int posXinSubset     = posX & ((1 << MLS_CG_LOG2_SIZE) - 1);
-            const int posYinSubset     = posY & ((1 << MLS_CG_LOG2_SIZE) - 1);
-            const int posTotalInSubset = posXinSubset + posYinSubset;
+    int cnt = table_cnt[patternSigCtx][posXinSubset][posYinSubset];
+    int offset = codingParameters.firstSignificanceMapContext;
 
-            //first N coefficients in scan order use 2; the next few use 1; the rest use 0.
-            const uint32_t context1Threshold = NEIGHBOURHOOD_00_CONTEXT_1_THRESHOLD_4x4;
-            const uint32_t context2Threshold = NEIGHBOURHOOD_00_CONTEXT_2_THRESHOLD_4x4;
+    offset += cnt;
 
-            cnt = (posTotalInSubset >= context1Threshold) ? 0 : ((posTotalInSubset >= context2Threshold) ? 1 : 2);
-        }
-        break;
-
-        case 1: //right group is significant, below is not
-        {
-            const int posYinSubset = posY & ((1 << MLS_CG_LOG2_SIZE) - 1);
-            const int groupHeight  = 1 << MLS_CG_LOG2_SIZE;
-
-            cnt = (posYinSubset >= (groupHeight >> 1)) ? 0 : ((posYinSubset >= (groupHeight >> 2)) ? 1 : 2); //top quarter uses 2; second-from-top quarter uses 1; bottom half uses 0
-        }
-        break;
-
-        case 2: //below group is significant, right is not
-        {
-            const int posXinSubset = posX & ((1 << MLS_CG_LOG2_SIZE)  - 1);
-            const int groupWidth   = 1 << MLS_CG_LOG2_SIZE;
-
-            cnt = (posXinSubset >= (groupWidth >> 1)) ? 0 : ((posXinSubset >= (groupWidth >> 2)) ? 1 : 2); //left quarter uses 2; second-from-left quarter uses 1; right half uses 0
-        }
-        break;
-
-        case 3: //both neighbouring groups are significant
-        {
-            cnt = 2;
-        }
-        break;
-
-        default:
-            x265_log(NULL, X265_LOG_ERROR, "TComTrQuant: ERROR - Invalid patternSigCtx");
-            exit(1);
-            break;
-        }
-
-        const bool notFirstGroup = ((posX >> MLS_CG_LOG2_SIZE) + (posY >> MLS_CG_LOG2_SIZE)) > 0;
-        TextType ctype = ttype == TEXT_LUMA ? TEXT_LUMA : TEXT_CHROMA;
-        offset = (notFirstGroup ? notFirstGroupNeighbourhoodContextOffset[ctype] : 0) + cnt;
-    }
-    return codingParameters.firstSignificanceMapContext + offset;
+    return (codingParameters.ctype == TEXT_LUMA && (posX | posY) >= 4) ? 3 + offset : offset;
 }
 
 /** Get the best level in RD sense
diff -r 82a66870fc8b -r d1d80d6baa3f source/Lib/TLibCommon/TComTrQuant.h
--- a/source/Lib/TLibCommon/TComTrQuant.h	Sun Mar 09 21:49:30 2014 -0500
+++ b/source/Lib/TLibCommon/TComTrQuant.h	Mon Mar 10 17:06:52 2014 +0900
@@ -159,7 +159,7 @@
     void processScalingListEnc(int32_t *coeff, int32_t *quantcoeff, int quantScales, uint32_t height, uint32_t width, uint32_t ratio, int sizuNum, uint32_t dc);
     void processScalingListDec(int32_t *coeff, int32_t *dequantcoeff, int invQuantScales, uint32_t height, uint32_t width, uint32_t ratio, int sizuNum, uint32_t dc);
     static int calcPatternSigCtx(const uint32_t* sigCoeffGroupFlag, uint32_t cgPosX, uint32_t cgPosY, uint32_t log2TrSizeCG);
-    static int getSigCtxInc(int patternSigCtx, const TUEntropyCodingParameters &codingParameters, const int scanPosition, const int log2TrSize, const TextType ttype);
+    static int getSigCtxInc(int patternSigCtx, const TUEntropyCodingParameters &codingParameters, const int blkPos);
     static uint32_t getSigCoeffGroupCtxInc(const uint32_t* sigCoeffGroupFlag, uint32_t cgPosX, uint32_t cgPosY, const uint32_t log2TrSizeCG);
     static void getTUEntropyCodingParameters(TComDataCU* cu, TUEntropyCodingParameters &result, uint32_t absPartIdx, uint32_t log2TrSize, TextType ttype);
     estBitsSbacStruct* m_estBitsSbac;
diff -r 82a66870fc8b -r d1d80d6baa3f source/Lib/TLibCommon/TypeDef.h
--- a/source/Lib/TLibCommon/TypeDef.h	Sun Mar 09 21:49:30 2014 -0500
+++ b/source/Lib/TLibCommon/TypeDef.h	Mon Mar 10 17:06:52 2014 +0900
@@ -176,6 +176,8 @@
     const uint32_t            *scan;
     const uint32_t            *scanCG;
     COEFF_SCAN_TYPE      scanType;
+    TextType             ctype;
+    uint32_t             log2TrSize;
     uint32_t             log2TrSizeCG;
     uint32_t             firstSignificanceMapContext;
 };
diff -r 82a66870fc8b -r d1d80d6baa3f source/Lib/TLibEncoder/TEncSbac.cpp
--- a/source/Lib/TLibEncoder/TEncSbac.cpp	Sun Mar 09 21:49:30 2014 -0500
+++ b/source/Lib/TLibEncoder/TEncSbac.cpp	Mon Mar 10 17:06:52 2014 +0900
@@ -2185,7 +2185,7 @@
                 sig     = (coeff[blkPos] != 0);
                 if (scanPosSig > subPos || subSet == 0 || numNonZero)
                 {
-                    ctxSig  = TComTrQuant::getSigCtxInc(patternSigCtx, codingParameters, scanPosSig, log2TrSize, ttype);
+                    ctxSig  = TComTrQuant::getSigCtxInc(patternSigCtx, codingParameters, blkPos);
                     m_binIf->encodeBin(sig, baseCtx[ctxSig]);
                 }
                 if (sig)


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