[x265] [PATCH] rd: determine CU complexity to skip analysis of higher depths

[kavitha at multicorewareinc.com]

# HG changeset patch
# User Kavitha Sampath <kavitha at multicorewareinc.com>
# Date 1466062058 -19800
#      Thu Jun 16 12:57:38 2016 +0530
# Node ID 0d3fe50466f995ad519e20d1dc7ab7ec6920db00
# Parent  78ffb67a844e3e76facf18c52790f1bd544754d6
rd: determine CU complexity to skip analysis of higher depths

Complexity check is performed for RD level 2 of 4K videos

diff -r 78ffb67a844e -r 0d3fe50466f9 source/encoder/analysis.cpp
--- a/source/encoder/analysis.cpp	Fri Jun 10 15:53:28 2016 +0530
+++ b/source/encoder/analysis.cpp	Thu Jun 16 12:57:38 2016 +0530
@@ -74,6 +74,7 @@
 {
     m_reuseInterDataCTU = NULL;
     m_reuseRef = NULL;
+    m_is4k = false;
 }
 bool Analysis::create(ThreadLocalData *tld)
 {
@@ -105,6 +106,8 @@
             md.pred[j].fencYuv = &md.fencYuv;
         }
     }
+    if (m_param->sourceWidth >= 3840)
+        m_is4k = true;
 
     return ok;
 }
@@ -944,8 +947,13 @@
     if (md.bestMode && m_param->bEnableRecursionSkip)
     {
         skipRecursion = md.bestMode->cu.isSkipped(0);
-        if (mightSplit && depth && depth >= minDepth && !skipRecursion)
-            skipRecursion = recursionDepthCheck(parentCTU, cuGeom, *md.bestMode);
+        if (mightSplit && depth >= minDepth && !skipRecursion)
+        {
+            if (depth)
+                skipRecursion = recursionDepthCheck(parentCTU, cuGeom, *md.bestMode);
+            if (m_is4k && !skipRecursion && m_param->rdLevel == 2 && md.fencYuv.m_size != MAX_CU_SIZE)
+                skipRecursion = complexityCheckCU(*md.bestMode);
+        }
     }
 
     /* Step 2. Evaluate each of the 4 split sub-blocks in series */
@@ -2593,6 +2601,30 @@
     return false;
 }
 
+bool Analysis::complexityCheckCU(const Mode& bestMode)
+{
+    uint32_t mean = 0;
+    uint32_t homo = 0;
+    uint32_t cuSize = bestMode.fencYuv->m_size;
+    for (uint32_t y = 0; y < cuSize; y++) {
+        for (uint32_t x = 0; x < cuSize; x++) {
+            mean += (bestMode.fencYuv->m_buf[0][y * cuSize + x]);
+        }
+    }
+    mean = mean / (cuSize * cuSize);
+    for (uint32_t y = 0 ; y < cuSize; y++){
+        for (uint32_t x = 0 ; x < cuSize; x++){
+            homo += abs(int(bestMode.fencYuv->m_buf[0][y * cuSize + x] - mean));
+        }
+    }
+    homo = homo / (cuSize * cuSize);
+
+    if (homo < (.1 * mean))
+        return true;
+
+    return false;
+}
+
 int Analysis::calculateQpforCuSize(const CUData& ctu, const CUGeom& cuGeom, double baseQp)
 {
     FrameData& curEncData = *m_frame->m_encData;
diff -r 78ffb67a844e -r 0d3fe50466f9 source/encoder/analysis.h
--- a/source/encoder/analysis.h	Fri Jun 10 15:53:28 2016 +0530
+++ b/source/encoder/analysis.h	Thu Jun 16 12:57:38 2016 +0530
@@ -108,6 +108,7 @@
     ModeDepth m_modeDepth[NUM_CU_DEPTH];
     bool      m_bTryLossless;
     bool      m_bChromaSa8d;
+    bool      m_is4k;
 
     Analysis();
 
@@ -160,6 +161,7 @@
     /* work-avoidance heuristics for RD levels < 5 */
     uint32_t topSkipMinDepth(const CUData& parentCTU, const CUGeom& cuGeom);
     bool recursionDepthCheck(const CUData& parentCTU, const CUGeom& cuGeom, const Mode& bestMode);
+    bool complexityCheckCU(const Mode& bestMode);
 
     /* generate residual and recon pixels for an entire CTU recursively (RD0) */
     void encodeResidue(const CUData& parentCTU, const CUGeom& cuGeom);