[x265] [PATCH REVIEW] Lookahead: Implement wavefront parallel processing

deepthidevaki at multicorewareinc.com deepthidevaki at multicorewareinc.com
Thu Oct 17 12:39:09 CEST 2013


# HG changeset patch
# User Deepthi Devaki <deepthidevaki at multicorewareinc.com>
# Date 1382006045 -19800
# Node ID 677d71fd793959c7e98df56f99f0b02a89fe050d
# Parent  fc9dbd798ac37ec1acc0596aa179f0deb586c092
Lookahead: Implement wavefront parallel processing

diff -r fc9dbd798ac3 -r 677d71fd7939 source/common/wavefront.h
--- a/source/common/wavefront.h	Thu Oct 17 14:14:40 2013 +0530
+++ b/source/common/wavefront.h	Thu Oct 17 16:04:05 2013 +0530
@@ -47,11 +47,6 @@
 
     int m_numRows;
 
-    // WaveFront's implementation of JobProvider::findJob. Consults
-    // m_queuedBitmap and calls ProcessRow(row) for lowest numbered queued row
-    // or returns false
-    bool findJob();
-
 public:
 
     WaveFront(ThreadPool *pool) : JobProvider(pool), m_queuedBitmap(0) {}
@@ -69,6 +64,11 @@
 
     void clearEnabledRowMask();
 
+    // WaveFront's implementation of JobProvider::findJob. Consults
+    // m_queuedBitmap and calls ProcessRow(row) for lowest numbered queued row
+    // or returns false
+    bool findJob();
+
     // Returns true if a row above curRow is available for processing.  The processRow()
     // method may call this function periodically and voluntarily exit
     bool checkHigherPriorityRow(int curRow);
diff -r fc9dbd798ac3 -r 677d71fd7939 source/encoder/encoder.cpp
--- a/source/encoder/encoder.cpp	Thu Oct 17 14:14:40 2013 +0530
+++ b/source/encoder/encoder.cpp	Thu Oct 17 16:04:05 2013 +0530
@@ -92,6 +92,7 @@
         }
     }
     m_lookahead = new Lookahead(this);
+    m_lookahead->setThreadPool(m_threadPool);
     m_dpb = new DPB(this);
     m_rateControl = new RateControl(this);
 }
@@ -144,6 +145,7 @@
             m_frameEncoder[i].init(this, numRows);
         }
     }
+    m_lookahead->init();
 }
 
 int Encoder::getStreamHeaders(NALUnitEBSP **nalunits)
diff -r fc9dbd798ac3 -r 677d71fd7939 source/encoder/slicetype.cpp
--- a/source/encoder/slicetype.cpp	Thu Oct 17 14:14:40 2013 +0530
+++ b/source/encoder/slicetype.cpp	Thu Oct 17 16:04:05 2013 +0530
@@ -62,29 +62,67 @@
     dst.y = median(a.y, b.y, c.y);
 }
 
-Lookahead::Lookahead(TEncCfg *_cfg)
+Lookahead::Lookahead(TEncCfg *_cfg) : WaveFront(NULL)
 {
     this->cfg = _cfg;
     numDecided = 0;
     lastKeyframe = -cfg->param.keyframeMax;
     lastNonB = NULL;
-    predictions = (pixel*)X265_MALLOC(pixel, 35 * 8 * 8);
-    me.setQP(X265_LOOKAHEAD_QP);
-    me.setSearchMethod(X265_HEX_SEARCH);
-    me.setSubpelRefine(1);
     merange = 16;
     widthInCU = ((cfg->param.sourceWidth / 2) + X265_LOWRES_CU_SIZE - 1) >> X265_LOWRES_CU_BITS;
     heightInCU = ((cfg->param.sourceHeight / 2) + X265_LOWRES_CU_SIZE - 1) >> X265_LOWRES_CU_BITS;
+
+    lock = new Lock[heightInCU];
+    rowme = new MotionEstimate[heightInCU];
+
+    active = (bool*)X265_MALLOC(bool, heightInCU);
+    completed = (uint32_t*)X265_MALLOC(uint32_t, heightInCU);
+    rowpredictions = (pixel**)X265_MALLOC(pixel*, heightInCU);
+    rowcostEst = (int*)X265_MALLOC(int, heightInCU);
+    rowcostIntra = (int*)X265_MALLOC(int, heightInCU);
+    rowIntraMbs = (int*)X265_MALLOC(int, heightInCU);
+    for (int i = 0; i < heightInCU; i++)
+    {
+        rowme[i].setQP(X265_LOOKAHEAD_QP);
+        rowme[i].setSearchMethod(X265_HEX_SEARCH);
+        rowme[i].setSubpelRefine(1);
+        rowpredictions[i] = (pixel*)X265_MALLOC(pixel, 35 * 8 * 8);
+        rowcostEst[i] = 0;
+        rowcostIntra[i] = 0;
+        rowIntraMbs[i] = 0;
+    }
 }
 
 Lookahead::~Lookahead()
 {
 }
 
+void Lookahead::init()
+{
+    if (!WaveFront::init(heightInCU))
+    {
+        m_pool = NULL;
+    }
+    memset((void*)completed, 0, heightInCU * sizeof(uint32_t));
+    memset((void*)active, 0, heightInCU * sizeof(bool));
+}
+
 void Lookahead::destroy()
 {
-    if (predictions)
-        X265_FREE(predictions);
+    delete[] lock;
+    delete[] rowme;
+
+    X265_FREE((void*)active);
+    X265_FREE((void*)completed);
+    for (int i = 0; i < heightInCU; i++)
+    {
+        X265_FREE(rowpredictions[i]);
+    }
+
+    X265_FREE(rowpredictions);
+    X265_FREE(rowcostEst);
+    X265_FREE(rowcostIntra);
+    X265_FREE(rowIntraMbs);
 
     // these two queues will be empty, unless the encode was aborted
     while (!inputQueue.empty())
@@ -165,9 +203,12 @@
 int Lookahead::estimateFrameCost(int p0, int p1, int b, bool bIntraPenalty)
 {
     int score = 0;
-    bool bDoSearch[2];
     Lowres *fenc = frames[b];
 
+    curb = b;
+    curp0 = p0;
+    curp1 = p1;
+
     if (fenc->costEst[b - p0][p1 - b] >= 0 && fenc->rowSatds[b - p0][p1 - b][0] != -1)
         score = fenc->costEst[b - p0][p1 - b];
     else
@@ -185,23 +226,58 @@
          * predictors in the main encode.  This considerably improves MV
          * prediction overall. */
         // TODO: use lowres MVs as motion candidates in full-res search
-        me.setSourcePlane(fenc->lowresPlane[0], fenc->lumaStride);
-        for (int j = heightInCU - 1; j >= 0; j--)
+
+        for (int i = 0; i < heightInCU; i++)
         {
-            if (!fenc->bIntraCalculated)
-                fenc->rowSatds[0][0][j] = 0;
-            fenc->rowSatds[b - p0][p1 - b][j] = 0;
+            rowme[i].setSourcePlane(fenc->lowresPlane[0], fenc->lumaStride);
+        }
 
-            for (int i = widthInCU - 1; i >= 0; i--)
+        memset((void*)completed, 0, heightInCU * sizeof(uint32_t));
+        memset((void*)active, 0, heightInCU * sizeof(bool));
+        memset((void*)rowcostEst, 0, heightInCU * sizeof(int));
+        memset((void*)rowcostIntra, 0, heightInCU * sizeof(int));
+        memset((void*)rowIntraMbs, 0, heightInCU * sizeof(int));
+        rowsCompleted = false;
+
+        if (m_pool && cfg->param.bEnableWavefront)
+        {
+            WaveFront::clearEnabledRowMask();
+            WaveFront::enqueue();
+
+            for (int row = 0; row < heightInCU; row++)
             {
-                estimateCUCost(i, j, p0, p1, b, bDoSearch);
+                enableRow(row);
+                if (row == 0)
+                    enqueueRow(0);
+                else
+                    m_pool->pokeIdleThread();
+            }
+
+            while (!rowsCompleted)
+            {
+                WaveFront::findJob();
+            }
+
+            WaveFront::dequeue();
+        }
+        else
+        {
+            for (int row = 0; row < heightInCU; row++)
+            {
+                processRow(row);
             }
         }
 
+        //Accumulate cost from each row
+        for (int row = 0; row < heightInCU; row++)
+        {
+            score += rowcostEst[row];
+            fenc->costEst[0][0] += rowcostIntra[row];
+            fenc->intraMbs[b - p0] += rowIntraMbs[row];
+        }
+
         fenc->bIntraCalculated = true;
 
-        score = fenc->costEst[b - p0][p1 - b];
-
         if (b != p1)
             score = (uint64_t)score * 100 / (130 + cfg->param.bFrameBias);
 
@@ -218,7 +294,7 @@
     return score;
 }
 
-void Lookahead::estimateCUCost(int cux, int cuy, int p0, int p1, int b, bool bDoSearch[2])
+void Lookahead::estimateCUCost(int cux, int cuy, int p0, int p1, int b, bool bDoSearch[2], int row)
 {
     Lowres *fref0 = frames[p0];
     Lowres *fref1 = frames[p1];
@@ -233,7 +309,7 @@
     const bool bFrameScoreCU = (cux > 0 && cux < widthInCU - 1 &&
                                 cuy > 0 && cuy < heightInCU - 1) || widthInCU <= 2 || heightInCU <= 2;
 
-    me.setSourcePU(pelOffset, cuSize, cuSize);
+    rowme[row].setSourcePU(pelOffset, cuSize, cuSize);
 
     MV(*fenc_mvs[2]) = { &fenc->lowresMvs[0][b - p0 - 1][cuXY],
                          &fenc->lowresMvs[1][p1 - b - 1][cuXY] };
@@ -241,7 +317,7 @@
                             &fenc->lowresMvCosts[1][p1 - b - 1][cuXY] };
 
     MV mvmin, mvmax;
-    int bcost = me.COST_MAX;
+    int bcost = rowme[row].COST_MAX;
     int listused = 0;
 
     // establish search bounds that don't cross extended frame boundaries
@@ -286,7 +362,7 @@
                 median_mv(mvp, mvc[0], mvc[1], mvc[2]);
             }
 
-            *fenc_costs[i] = me.motionEstimate(i ? fref1 : fref0, mvmin, mvmax, mvp, numc, mvc, merange, *fenc_mvs[i]);
+            *fenc_costs[i] = rowme[row].motionEstimate(i ? fref1 : fref0, mvmin, mvmax, mvp, numc, mvc, merange, *fenc_mvs[i]);
             COPY2_IF_LT(bcost, *fenc_costs[i], listused, i + 1);
         }
         if (bBidir)
@@ -388,23 +464,23 @@
         int predsize = cuSize * cuSize;
 
         // generate 35 intra predictions into tmp
-        primitives.intra_pred_dc(pAbove0 + 1, pLeft0 + 1, predictions, cuSize, cuSize, (cuSize <= 16));
+        primitives.intra_pred_dc(pAbove0 + 1, pLeft0 + 1, rowpredictions[row], cuSize, cuSize, (cuSize <= 16));
         pixel *above = (cuSize >= 8) ? pAbove1 : pAbove0;
         pixel *left  = (cuSize >= 8) ? pLeft1 : pLeft0;
-        primitives.intra_pred_planar((pixel*)above + 1, (pixel*)left + 1, predictions + predsize, cuSize, cuSize);
-        primitives.intra_pred_allangs[nLog2SizeMinus2](predictions + 2 * predsize, pAbove0, pLeft0, pAbove1, pLeft1, (cuSize <= 16));
+        primitives.intra_pred_planar((pixel*)above + 1, (pixel*)left + 1, rowpredictions[row] + predsize, cuSize, cuSize);
+        primitives.intra_pred_allangs[nLog2SizeMinus2](rowpredictions[row] + 2 * predsize, pAbove0, pLeft0, pAbove1, pLeft1, (cuSize <= 16));
 
         // calculate 35 satd costs, keep least cost
         ALIGN_VAR_32(pixel, buf_trans[32 * 32]);
-        primitives.transpose[nLog2SizeMinus2](buf_trans, me.fenc, FENC_STRIDE);
+        primitives.transpose[nLog2SizeMinus2](buf_trans, rowme[row].fenc, FENC_STRIDE);
         pixelcmp_t satd = primitives.satd[PartitionFromSizes(cuSize, cuSize)];
-        int icost = me.COST_MAX, cost;
+        int icost = rowme[row].COST_MAX, cost;
         for (UInt mode = 0; mode < 35; mode++)
         {
             if ((mode >= 2) && (mode < 18))
-                cost = satd(buf_trans, cuSize, &predictions[mode * predsize], cuSize);
+                cost = satd(buf_trans, cuSize, &rowpredictions[row][mode * predsize], cuSize);
             else
-                cost = satd(me.fenc, FENC_STRIDE, &predictions[mode * predsize], cuSize);
+                cost = satd(rowme[row].fenc, FENC_STRIDE, &rowpredictions[row][mode * predsize], cuSize);
             if (cost < icost)
                 icost = cost;
         }
@@ -412,14 +488,14 @@
         // TOOD: i_icost += intra_penalty + lowres_penalty;
         fenc->intraCost[cuXY] = icost;
         fenc->rowSatds[0][0][cuy] += icost;
-        if (bFrameScoreCU) fenc->costEst[0][0] += icost;
+        if (bFrameScoreCU) rowcostIntra[row] += icost;
     }
 
     if (!bBidir)
     {
         if (fenc->intraCost[cuXY] < bcost)
         {
-            if (bFrameScoreCU) fenc->intraMbs[b - p0]++;
+            if (bFrameScoreCU) rowIntraMbs[row]++;
             bcost = fenc->intraCost[cuXY];
             listused = 0;
         }
@@ -429,7 +505,7 @@
     if (p0 != p1)
     {
         fenc->rowSatds[b - p0][p1 - b][cuy] += bcost;
-        if (bFrameScoreCU) fenc->costEst[b - p0][p1 - b] += bcost;
+        if (bFrameScoreCU) rowcostEst[row] += bcost;
     }
     fenc->lowresCosts[b - p0][p1 - b][cuXY] = (uint16_t)(X265_MIN(bcost, LOWRES_COST_MASK) | (listused << LOWRES_COST_SHIFT));
 }
@@ -547,6 +623,7 @@
             {
                 frames[i + 1] = &list[i]->m_lowres;
             }
+
             if (IS_X265_TYPE_I(frames[bframes + 1]->sliceType))
                 p0 = bframes + 1;
             else // P
@@ -914,7 +991,7 @@
 {
     char paths[2][X265_LOOKAHEAD_MAX + 1];
     int num_paths = X265_MIN(cfg->param.bframes + 1, length);
-    int best_cost = me.COST_MAX;
+    int best_cost = rowme[0].COST_MAX;
     int idx = 0;
 
     /* Iterate over all currently possible paths */
@@ -993,3 +1070,41 @@
 
     return cost;
 }
+
+void Lookahead::processRow(int row)
+{
+    int realrow = heightInCU - 1 - row;
+    Lowres *fenc = frames[curb];
+
+    if (!fenc->bIntraCalculated)
+        fenc->rowSatds[0][0][realrow] = 0;
+    fenc->rowSatds[curb - curp0][curp1 - curb][realrow] = 0;
+    for (int i = widthInCU - 1 - completed[row]; i >= 0; i--) //Go backwards
+    {
+        estimateCUCost(i, realrow, curp0, curp1, curb, bDoSearch, row);
+        completed[row]++;
+
+        if (completed[row] >= 2 && row < heightInCU - 1)
+        {
+            ScopedLock below(lock[row + 1]);
+            if (active[row + 1] == false &&
+                completed[row + 1] + 2 <= completed[row])
+            {
+                active[row + 1] = true;
+                enqueueRow(row + 1);
+            }
+        }
+
+        ScopedLock self(lock[row]);
+        if (row > 0 && (int32_t)completed[row] < widthInCU - 1 && completed[row - 1] < completed[row] + 2)
+        {
+            active[row] = false;
+            return;
+        }
+    }
+
+    if (row == heightInCU - 1)
+    {
+        rowsCompleted = true;
+    }
+}
diff -r fc9dbd798ac3 -r 677d71fd7939 source/encoder/slicetype.h
--- a/source/encoder/slicetype.h	Thu Oct 17 14:14:40 2013 +0530
+++ b/source/encoder/slicetype.h	Thu Oct 17 16:04:05 2013 +0530
@@ -26,7 +26,7 @@
 
 #include "motion.h"
 #include "piclist.h"
-#include "common.h"
+#include "wavefront.h"
 
 namespace x265 {
 // private namespace
@@ -35,11 +35,9 @@
 class TComPic;
 class TEncCfg;
 
-struct Lookahead
+struct Lookahead : public WaveFront
 {
-    MotionEstimate   me;
     TEncCfg         *cfg;
-    pixel           *predictions;   // buffer for 35 intra predictions
     Lowres          *frames[X265_LOOKAHEAD_MAX];
     Lowres          *lastNonB;
     int              merange;
@@ -51,9 +49,24 @@
     PicList inputQueue;  // input pictures in order received
     PicList outputQueue; // pictures to be encoded, in encode order
 
+    bool bDoSearch[2];
+    int curb, curp0, curp1;
+    bool rowsCompleted;
+
+    //For wavefront parallelism
+    Lock*                lock;
+    volatile bool*       active;
+    volatile uint32_t*   completed;
+    pixel**              rowpredictions;    // buffer for 35 intra predictions
+    MotionEstimate*      rowme;
+    int*                 rowcostEst;
+    int*                 rowcostIntra;
+    int*                 rowIntraMbs;
+
     Lookahead(TEncCfg *);
     ~Lookahead();
 
+    void init();
     void addPicture(TComPic*, int sliceType);
     void flush();
     void destroy();
@@ -61,13 +74,15 @@
     int getEstimatedPictureCost(TComPic *pic);
 
     int estimateFrameCost(int p0, int p1, int b, bool bIntraPenalty);
-    void estimateCUCost(int cux, int cuy, int p0, int p1, int b, bool bDoSearch[2]);
+    void estimateCUCost(int cux, int cuy, int p0, int p1, int b, bool bDoSearch[2], int row);
 
     void slicetypeAnalyse(bool bKeyframe);
     int scenecut(int p0, int p1, bool bRealScenecut, int numFrames, int maxSearch);
     int scenecutInternal(int p0, int p1, bool bRealScenecut);
     void slicetypePath(int length, char(*best_paths)[X265_LOOKAHEAD_MAX + 1]);
     int slicetypePathCost(char *path, int threshold);
+
+    void processRow(int row);
 };
 }
 


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