[x265] [PATCH] analysis: re-order RD 5/6 analysis to do splits before ME or intra
Steve Borho
steve at borho.org
Tue May 26 13:46:54 CEST 2015
On 05/26, Deepthi Nandakumar wrote:
> On Mon, May 25, 2015 at 8:31 PM, <ashok at multicorewareinc.com> wrote:
>
> > # HG changeset patch
> > # User Ashok Kumar Mishra<ashok at multicorewareinc.com>
> > # Date 1432215988 -19800
> > # Thu May 21 19:16:28 2015 +0530
> > # Node ID b11c2f1f8425425cfe190a45c710b65304d07db1
> > # Parent a7bf7a150a705489cb63d0454c59ec599bad8c93
> > analysis: re-order RD 5/6 analysis to do splits before ME or intra
> >
> > This commit changes outputs because splits used to be avoided when an
> > inter or
> > intra mode was chosen without residual coding. This recursion early-out is
> > no
> > longer possible. Only merge without residual (aka skip) can abort
> > recursion.
> >
> > This commit changes the order of analysis such that the four split blocks
> > are
> > analyzed prior to attempting any ME or intra modes. Future commits we will
> > use
> > the knowledge learned during split analysis to avoid unlikely work at the
> > current depth (reducing motion references avoiding unlikely intra,
> > rectangular,
> > asymmetric, and lossless modes)
>
> Ok, I've edited this commit message, because this gives the impression
> that the new patch introduces
> less early outs, whereas the new patch now makes early outs more likely.
> Earlier : Abort recursion if Best(Merge, Skip, All Inter, Intra ) is
> a skip mode
> New patch : Abort recursion of Best(Merge Skip) is a skip mode.
>
> We should do some subjective quality testing before we push this in. Is
> this making skips more likely and blurring the video?
FWIW: skips are normally not blurry, but I agree with subjective testing
of the changes.
> > diff -r a7bf7a150a70 -r b11c2f1f8425 source/encoder/analysis.cpp
> > --- a/source/encoder/analysis.cpp Fri May 22 14:29:35 2015 +0530
> > +++ b/source/encoder/analysis.cpp Thu May 21 19:16:28 2015 +0530
> > @@ -1170,14 +1170,72 @@
> > }
> > }
> >
> > + bool foundSkip = false;
> > + /* Step 1. Evaluate Merge/Skip candidates for likely early-outs */
> > if (mightNotSplit)
> > {
> > md.pred[PRED_SKIP].cu.initSubCU(parentCTU, cuGeom, qp);
> > md.pred[PRED_MERGE].cu.initSubCU(parentCTU, cuGeom, qp);
> > checkMerge2Nx2N_rd5_6(md.pred[PRED_SKIP], md.pred[PRED_MERGE],
> > cuGeom, false);
> > - bool earlySkip = m_param->bEnableEarlySkip && md.bestMode &&
> > !md.bestMode->cu.getQtRootCbf(0);
> > + foundSkip = md.bestMode && !md.bestMode->cu.getQtRootCbf(0);
> > + }
> >
> > - if (!earlySkip)
> > + // estimate split cost
> > + /* Step 2. Evaluate each of the 4 split sub-blocks in series */
> > + if (mightSplit && !foundSkip)
> > + {
> > + Mode* splitPred = &md.pred[PRED_SPLIT];
> > + splitPred->initCosts();
> > + CUData* splitCU = &splitPred->cu;
> > + splitCU->initSubCU(parentCTU, cuGeom, qp);
> > +
> > + uint32_t nextDepth = depth + 1;
> > + ModeDepth& nd = m_modeDepth[nextDepth];
> > + invalidateContexts(nextDepth);
> > + Entropy* nextContext = &m_rqt[depth].cur;
> > + int nextQP = qp;
> > +
> > + for (uint32_t subPartIdx = 0; subPartIdx < 4; subPartIdx++)
> > + {
> > + const CUGeom& childGeom = *(&cuGeom + cuGeom.childOffset +
> > subPartIdx);
> > + if (childGeom.flags & CUGeom::PRESENT)
> > + {
> > + m_modeDepth[0].fencYuv.copyPartToYuv(nd.fencYuv,
> > childGeom.absPartIdx);
> > + m_rqt[nextDepth].cur.load(*nextContext);
> > +
> > + if (m_slice->m_pps->bUseDQP && nextDepth <=
> > m_slice->m_pps->maxCuDQPDepth)
> > + nextQP = setLambdaFromQP(parentCTU,
> > calculateQpforCuSize(parentCTU, childGeom));
> > +
> > + compressInterCU_rd5_6(parentCTU, childGeom, zOrder,
> > nextQP);
> > +
> > + // Save best CU and pred data for this sub CU
> > + splitCU->copyPartFrom(nd.bestMode->cu, childGeom,
> > subPartIdx);
> > + splitPred->addSubCosts(*nd.bestMode);
> > + nd.bestMode->reconYuv.copyToPartYuv(splitPred->reconYuv,
> > childGeom.numPartitions * subPartIdx);
> > + nextContext = &nd.bestMode->contexts;
> > + }
> > + else
> > + {
> > + splitCU->setEmptyPart(childGeom, subPartIdx);
> > + zOrder += g_depthInc[g_maxCUDepth - 1][nextDepth];
> > + }
> > + }
> > + nextContext->store(splitPred->contexts);
> > + if (mightNotSplit)
> > + addSplitFlagCost(*splitPred, cuGeom.depth);
> > + else
> > + updateModeCost(*splitPred);
> > +
> > + checkDQPForSplitPred(*splitPred, cuGeom);
> > + }
> > +
> > + /* Step 3. Evaluate ME (2Nx2N, rect, amp) and intra modes at current
> > depth */
> > + if (mightNotSplit)
> > + {
> > + if (m_slice->m_pps->bUseDQP && depth <=
> > m_slice->m_pps->maxCuDQPDepth && m_slice->m_pps->maxCuDQPDepth != 0)
> > + setLambdaFromQP(parentCTU, qp);
> > +
> > + if (!(foundSkip && m_param->bEnableEarlySkip))
> > {
> > md.pred[PRED_2Nx2N].cu.initSubCU(parentCTU, cuGeom, qp);
> > checkInter_rd5_6(md.pred[PRED_2Nx2N], cuGeom, SIZE_2Nx2N);
> > @@ -1263,59 +1321,13 @@
> > addSplitFlagCost(*md.bestMode, cuGeom.depth);
> > }
> >
> > - // estimate split cost
> > - if (mightSplit && (!md.bestMode || !md.bestMode->cu.isSkipped(0)))
> > - {
> > - Mode* splitPred = &md.pred[PRED_SPLIT];
> > - splitPred->initCosts();
> > - CUData* splitCU = &splitPred->cu;
> > - splitCU->initSubCU(parentCTU, cuGeom, qp);
> > -
> > - uint32_t nextDepth = depth + 1;
> > - ModeDepth& nd = m_modeDepth[nextDepth];
> > - invalidateContexts(nextDepth);
> > - Entropy* nextContext = &m_rqt[depth].cur;
> > - int nextQP = qp;
> > -
> > - for (uint32_t subPartIdx = 0; subPartIdx < 4; subPartIdx++)
> > - {
> > - const CUGeom& childGeom = *(&cuGeom + cuGeom.childOffset +
> > subPartIdx);
> > - if (childGeom.flags & CUGeom::PRESENT)
> > - {
> > - m_modeDepth[0].fencYuv.copyPartToYuv(nd.fencYuv,
> > childGeom.absPartIdx);
> > - m_rqt[nextDepth].cur.load(*nextContext);
> > -
> > - if (m_slice->m_pps->bUseDQP && nextDepth <=
> > m_slice->m_pps->maxCuDQPDepth)
> > - nextQP = setLambdaFromQP(parentCTU,
> > calculateQpforCuSize(parentCTU, childGeom));
> > -
> > - compressInterCU_rd5_6(parentCTU, childGeom, zOrder,
> > nextQP);
> > -
> > - // Save best CU and pred data for this sub CU
> > - splitCU->copyPartFrom(nd.bestMode->cu, childGeom,
> > subPartIdx);
> > - splitPred->addSubCosts(*nd.bestMode);
> > - nd.bestMode->reconYuv.copyToPartYuv(splitPred->reconYuv,
> > childGeom.numPartitions * subPartIdx);
> > - nextContext = &nd.bestMode->contexts;
> > - }
> > - else
> > - {
> > - splitCU->setEmptyPart(childGeom, subPartIdx);
> > - zOrder += g_depthInc[g_maxCUDepth - 1][nextDepth];
> > - }
> > - }
> > - nextContext->store(splitPred->contexts);
> > - if (mightNotSplit)
> > - addSplitFlagCost(*splitPred, cuGeom.depth);
> > - else
> > - updateModeCost(*splitPred);
> > -
> > - checkDQPForSplitPred(*splitPred, cuGeom);
> > - checkBestMode(*splitPred, depth);
> > - }
> > + /* compare split RD cost against best cost */
> > + if (mightSplit && !foundSkip)
> > + checkBestMode(md.pred[PRED_SPLIT], depth);
> >
> > /* Copy best data to encData CTU and recon */
> > md.bestMode->cu.copyToPic(depth);
> > - if (md.bestMode != &md.pred[PRED_SPLIT])
> > - md.bestMode->reconYuv.copyToPicYuv(*m_frame->m_reconPic,
> > parentCTU.m_cuAddr, cuGeom.absPartIdx);
> > + md.bestMode->reconYuv.copyToPicYuv(*m_frame->m_reconPic,
> > parentCTU.m_cuAddr, cuGeom.absPartIdx);
> > }
> >
> > /* sets md.bestMode if a valid merge candidate is found, else leaves it
> > NULL */
> > _______________________________________________
> > x265-devel mailing list
> > x265-devel at videolan.org
> > https://mailman.videolan.org/listinfo/x265-devel
> >
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--
Steve Borho
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