[x265] [PATCH] improved getTUEntropyCodingParameters() function

[ashok at multicorewareinc.com]

# HG changeset patch
# User Ashok Kumar Mishra<ashok at multicorewareinc.com>
# Date 1424765356 -19800
#      Tue Feb 24 13:39:16 2015 +0530
# Node ID 0a570547df48890dd7db0df2559f42f874292f8f
# Parent  f513ae68dd7eb8c72f44dd74ea151041fea82492
improved getTUEntropyCodingParameters() function

diff -r f513ae68dd7e -r 0a570547df48 source/common/cudata.cpp
--- a/source/common/cudata.cpp	Wed Feb 25 16:38:59 2015 +0530
+++ b/source/common/cudata.cpp	Tue Feb 24 13:39:16 2015 +0530
@@ -1980,60 +1980,47 @@
                            + (puWidth  >> (LOG2_UNIT_SIZE + 1))];
 }
 
-ScanType CUData::getCoefScanIdx(uint32_t absPartIdx, uint32_t log2TrSize, bool bIsLuma, bool bIsIntra) const
-{
-    uint32_t dirMode;
-
-    if (!bIsIntra)
-        return SCAN_DIAG;
-
-    // check that MDCS can be used for this TU
-    if (bIsLuma)
-    {
-        if (log2TrSize > MDCS_LOG2_MAX_SIZE)
-            return SCAN_DIAG;
-
-        dirMode = m_lumaIntraDir[absPartIdx];
-    }
-    else
-    {
-        if (log2TrSize > (uint32_t)(MDCS_LOG2_MAX_SIZE - m_hChromaShift))
-            return SCAN_DIAG;
-
-        dirMode = m_chromaIntraDir[absPartIdx];
-        if (dirMode == DM_CHROMA_IDX)
-        {
-            dirMode = m_lumaIntraDir[(m_chromaFormat == X265_CSP_I444) ? absPartIdx : absPartIdx & 0xFC];
-            dirMode = (m_chromaFormat == X265_CSP_I422) ? g_chroma422IntraAngleMappingTable[dirMode] : dirMode;
-        }
-    }
-
-    if (abs((int)dirMode - VER_IDX) <= MDCS_ANGLE_LIMIT)
-        return SCAN_HOR;
-    else if (abs((int)dirMode - HOR_IDX) <= MDCS_ANGLE_LIMIT)
-        return SCAN_VER;
-    else
-        return SCAN_DIAG;
-}
-
 void CUData::getTUEntropyCodingParameters(TUEntropyCodingParameters &result, uint32_t absPartIdx, uint32_t log2TrSize, bool bIsLuma) const
 {
+    bool bIsIntra = isIntra(absPartIdx);
+
     // set the group layout
     result.log2TrSizeCG = log2TrSize - 2;
 
     // set the scan orders
-    result.scanType = getCoefScanIdx(absPartIdx, log2TrSize, bIsLuma, isIntra(absPartIdx));
+    if (!bIsIntra)
+    {
+        result.scanType = SCAN_DIAG;
+    }
+    else
+    {
+        uint32_t dirMode;
+
+        if (bIsLuma)
+            dirMode = m_lumaIntraDir[absPartIdx];
+        else
+        {
+            dirMode = m_chromaIntraDir[absPartIdx];
+            if (dirMode == DM_CHROMA_IDX)
+            {
+                dirMode = m_lumaIntraDir[(m_chromaFormat == X265_CSP_I444) ? absPartIdx : absPartIdx & 0xFC];
+                dirMode = (m_chromaFormat == X265_CSP_I422) ? g_chroma422IntraAngleMappingTable[dirMode] : dirMode;
+            }
+        }
+
+        if (log2TrSize <= (MDCS_LOG2_MAX_SIZE - m_hChromaShift) || (bIsLuma && log2TrSize == MDCS_LOG2_MAX_SIZE))
+            result.scanType = dirMode >= 22 && dirMode <= 30 ? SCAN_HOR : dirMode >= 6 && dirMode <= 14 ? SCAN_VER : SCAN_DIAG;
+        else
+            result.scanType = SCAN_DIAG;
+    }
+
     result.scan     = g_scanOrder[result.scanType][log2TrSize - 2];
     result.scanCG   = g_scanOrderCG[result.scanType][result.log2TrSizeCG];
 
     if (log2TrSize == 2)
         result.firstSignificanceMapContext = 0;
     else if (log2TrSize == 3)
-    {
-        result.firstSignificanceMapContext = 9;
-        if (result.scanType != SCAN_DIAG && bIsLuma)
-            result.firstSignificanceMapContext += 6;
-    }
+        result.firstSignificanceMapContext = (result.scanType != SCAN_DIAG && bIsLuma) ? 15 : 9;
     else
         result.firstSignificanceMapContext = bIsLuma ? 21 : 12;
 }
diff -r f513ae68dd7e -r 0a570547df48 source/common/cudata.h
--- a/source/common/cudata.h	Wed Feb 25 16:38:59 2015 +0530
+++ b/source/common/cudata.h	Tue Feb 24 13:39:16 2015 +0530
@@ -122,9 +122,9 @@
     uint32_t      m_cuPelY;           // CU position within the picture, in pixels (Y)
     uint32_t      m_numPartitions;    // maximum number of 4x4 partitions within this CU
 
-    int           m_chromaFormat;
-    int           m_hChromaShift;
-    int           m_vChromaShift;
+    uint32_t      m_chromaFormat;
+    uint32_t      m_hChromaShift;
+    uint32_t      m_vChromaShift;
 
     /* Per-part data, stored contiguously */
     int8_t*       m_qp;               // array of QP values
@@ -216,7 +216,6 @@
     uint32_t getSCUAddr() const                  { return (m_cuAddr << g_unitSizeDepth * 2) + m_absIdxInCTU; }
     uint32_t getCtxSplitFlag(uint32_t absPartIdx, uint32_t depth) const;
     uint32_t getCtxSkipFlag(uint32_t absPartIdx) const;
-    ScanType getCoefScanIdx(uint32_t absPartIdx, uint32_t log2TrSize, bool bIsLuma, bool bIsIntra) const;
     void     getTUEntropyCodingParameters(TUEntropyCodingParameters &result, uint32_t absPartIdx, uint32_t log2TrSize, bool bIsLuma) const;
 
     const CUData* getPULeft(uint32_t& lPartUnitIdx, uint32_t curPartUnitIdx) const;