[x265] [PATCH] analysis: Fix blocking artifacts while sharing best merge candidates

[Gopu Govindaswamy]

On Fri, Jun 12, 2015 at 8:47 PM, Steve Borho <steve at borho.org> wrote:

> On 06/12, gopu at multicorewareinc.com wrote:
> > # HG changeset patch
> > # User Gopu Govindaswamy <gopu at multicorewareinc.com>
> > # Date 1434098206 -19800
> > #      Fri Jun 12 14:06:46 2015 +0530
> > # Node ID e0327556bbcda705af8689ec0a77206599f5de61
> > # Parent  2cd9183df03edff0b148bab6e133dfe1ae4f69a1
> > analysis: Fix blocking artifacts while sharing best merge candidates
> >
> > While ecoding with --analysis-mode=load mode noticed there will blocking
> > artifacts, this issue is while sharing best merge candidate,
> >
> > when sharing the merge candidate before selecting the best mode (SKIP
> MODE),
> > first encode merge with residual (no skip) and if this mode hasCbf then
> try
> > merge without residual(skip) then select the best mode (SKIP MODE) from
> this two
> >
> > diff -r 2cd9183df03e -r e0327556bbcd source/encoder/analysis.cpp
> > --- a/source/encoder/analysis.cpp     Thu Jun 11 17:06:46 2015 +0530
> > +++ b/source/encoder/analysis.cpp     Fri Jun 12 14:06:46 2015 +0530
> > @@ -1455,19 +1455,50 @@
> >      bool foundCbf0Merge = false;
> >      bool triedPZero = false, triedBZero = false;
> >      bestPred->rdCost = MAX_INT64;
> > +    uint8_t hasCbf = true;
> > +    bool swapped = false;
> >
> >      if (isSkipMode)
>
> this ends up being a lot of duplicate code.
>
> How about something like this instead?
>
>   uint32_t first = 0, last = numMergeCand - 1;
>   if (isSkipMode)
>       first = last = *m_reuseBestMergeCand;
>
>   for (uint32_t i = first; i <= last; i++)
>   {
>     ...
>   }
>
> also, isSkipMode should probably be renamed
>

yes  This is looks fine, i will resend the patch with the modifications

>
> >      {
> >          uint32_t i = *m_reuseBestMergeCand;
> > -        bestPred->cu.m_mvpIdx[0][0] = (uint8_t)i;
> > -        bestPred->cu.m_interDir[0] = candDir[i];
> > -        bestPred->cu.m_mv[0][0] = candMvField[i][0].mv;
> > -        bestPred->cu.m_mv[1][0] = candMvField[i][1].mv;
> > -        bestPred->cu.m_refIdx[0][0] = (int8_t)candMvField[i][0].refIdx;
> > -        bestPred->cu.m_refIdx[1][0] = (int8_t)candMvField[i][1].refIdx;
> > +        tempPred->cu.m_mvpIdx[0][0] = (uint8_t)i;    /* merge candidate
> ID is stored in L0 MVP idx */
> > +        tempPred->cu.m_interDir[0] = candDir[i];
> > +        tempPred->cu.m_mv[0][0] = candMvField[i][0].mv;
> > +        tempPred->cu.m_mv[1][0] = candMvField[i][1].mv;
> > +        tempPred->cu.m_refIdx[0][0] = (int8_t)candMvField[i][0].refIdx;
> > +        tempPred->cu.m_refIdx[1][0] = (int8_t)candMvField[i][1].refIdx;
> > +        tempPred->cu.setPredModeSubParts(MODE_INTER); /* must be
> cleared between encode iterations */
> >
> > -        motionCompensation(bestPred->cu, pu, bestPred->predYuv, true,
> true);
> > -        encodeResAndCalcRdSkipCU(*bestPred);
> > +        motionCompensation(tempPred->cu, pu, tempPred->predYuv, true,
> true);
> > +
> > +        /* if the best prediction has CBF (not a skip) then try merge
> with residual */
> > +        encodeResAndCalcRdInterCU(*tempPred, cuGeom);
> > +        if (tempPred->rdCost < bestPred->rdCost)
> > +        {
> > +            hasCbf = tempPred->cu.getQtRootCbf(0);
> > +            std::swap(tempPred, bestPred);
> > +            swapped = true;
> > +        }
> > +
> > +        if (!m_param->bLossless && hasCbf)
> > +        {
> > +            if (swapped)
> > +            {
> > +                tempPred->cu.m_mvpIdx[0][0] = (uint8_t)i;
> > +                tempPred->cu.m_interDir[0] = candDir[i];
> > +                tempPred->cu.m_mv[0][0] = candMvField[i][0].mv;
> > +                tempPred->cu.m_mv[1][0] = candMvField[i][1].mv;
> > +                tempPred->cu.m_refIdx[0][0] =
> (int8_t)candMvField[i][0].refIdx;
> > +                tempPred->cu.m_refIdx[1][0] =
> (int8_t)candMvField[i][1].refIdx;
> > +                tempPred->cu.setPredModeSubParts(MODE_INTER);
> > +                tempPred->predYuv.copyFromYuv(bestPred->predYuv);
> > +            }
> > +
> > +            /* try merge without residual (skip), if not lossless
> coding */
> > +            encodeResAndCalcRdSkipCU(*tempPred);
> > +            if (tempPred->rdCost < bestPred->rdCost)
> > +                std::swap(tempPred, bestPred);
> > +        }
> >      }
> >      else
> >      {
> > @@ -1504,8 +1535,6 @@
> >
> >              motionCompensation(tempPred->cu, pu, tempPred->predYuv,
> true, true);
> >
> > -            uint8_t hasCbf = true;
> > -            bool swapped = false;
> >              if (!foundCbf0Merge)
> >              {
> >                  /* if the best prediction has CBF (not a skip) then try
> merge with residual */
> > _______________________________________________
> > x265-devel mailing list
> > x265-devel at videolan.org
> > https://mailman.videolan.org/listinfo/x265-devel
>
> --
> Steve Borho
> _______________________________________________
> x265-devel mailing list
> x265-devel at videolan.org
> https://mailman.videolan.org/listinfo/x265-devel
>



-- 
Thanks & Regards
Gopu G
Multicoreware Inc
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