[x265] [PATCH 1 of 2] rc: don't update predictors from previous frames, after reset at scenecut

[Deepthi Nandakumar]

On Thu, Sep 24, 2015 at 1:56 PM, <aarthi at multicorewareinc.com> wrote:

> # HG changeset patch
> # User Aarthi Thirumalai
> # Date 1442909407 -19800
> #      Tue Sep 22 13:40:07 2015 +0530
> # Branch stable
> # Node ID c44b32bc7c906456ad242dd237831ec96c1f5c3d
> # Parent  69d55d4c53ebff6d98e4431e0f8fe6103705b8ec
> rc: don't update predictors from previous frames, after reset at scenecut.
>
> diff -r 69d55d4c53eb -r c44b32bc7c90 source/encoder/ratecontrol.cpp
> --- a/source/encoder/ratecontrol.cpp    Tue Sep 22 13:33:13 2015 +0530
> +++ b/source/encoder/ratecontrol.cpp    Tue Sep 22 13:40:07 2015 +0530
> @@ -182,6 +182,7 @@
>      m_finalFrameCount = 0;
>      m_numEntries = 0;
>      m_isSceneTransition = false;
> +    m_lastPredictorReset = 0;
>      if (m_param->rc.rateControlMode == X265_RC_CRF)
>      {
>          m_param->rc.qp = (int)m_param->rc.rfConstant;
> @@ -370,20 +371,8 @@
>      m_accumPNorm = .01;
>      m_accumPQp = (m_param->rc.rateControlMode == X265_RC_CRF ?
> CRF_INIT_QP : ABR_INIT_QP_MIN) * m_accumPNorm;
>
> -    /* Frame Predictors and Row predictors used in vbv */
> -    for (int i = 0; i < 4; i++)
> -    {
> -        m_pred[i].coeff = 1.0;
> -        m_pred[i].count = 1.0;
> -        m_pred[i].decay = 0.5;
> -        m_pred[i].offset = 0.0;
> -    }
> -    m_pred[0].coeff = m_pred[3].coeff = 0.75;
> -    if (m_param->rc.qCompress >= 0.8) // when tuned for grain
> -    {
> -        m_pred[1].coeff = 0.75;
> -        m_pred[0].coeff = m_pred[3].coeff = 0.50;
> -    }
> +    /* Frame Predictors used in vbv */
> +    initFramePredictors();
>      if (!m_statFileOut && (m_param->rc.bStatWrite ||
> m_param->rc.bStatRead))
>      {
>          /* If the user hasn't defined the stat filename, use the default
> value */
> @@ -932,6 +921,24 @@
>          return X265_TYPE_AUTO;
>  }
>
> +void RateControl::initFramePredictors()
> +{
> +    /* Frame Predictors used in vbv */
> +    for (int i = 0; i < 4; i++)
> +    {
> +        m_pred[i].coeff = 1.0;
> +        m_pred[i].count = 1.0;
> +        m_pred[i].decay = 0.5;
> +        m_pred[i].offset = 0.0;
> +    }
> +    m_pred[0].coeff = m_pred[3].coeff = 0.75;
> +    if (m_param->rc.qCompress >= 0.8) // when tuned for grain
> +    {
> +        m_pred[1].coeff = 0.75;
> +        m_pred[0].coeff = m_pred[3].coeff = 0.50;
> +    }
> +}
> +
>  int RateControl::rateControlStart(Frame* curFrame, RateControlEntry* rce,
> Encoder* enc)
>  {
>      int orderValue = m_startEndOrder.get();
> @@ -961,23 +968,21 @@
>          copyRceData(rce, &m_rce2Pass[rce->poc]);
>      }
>      rce->isActive = true;
> -    bool isframeAfterKeyframe = m_sliceType != I_SLICE &&
> m_curSlice->m_refPicList[0][0]->m_encData->m_slice->m_sliceType == I_SLICE;
> +    bool isRefFrameScenecut = m_sliceType!= I_SLICE &&
> m_curSlice->m_refPicList[0][0]->m_lowres.bScenecut == 1;
>      if (curFrame->m_lowres.bScenecut)
>      {
>

This should be if (isRefFrameScenecut)?


>          m_isSceneTransition = true;
> -        /* Frame Predictors and Row predictors used in vbv */
> -        for (int i = 0; i < 4; i++)
> -        {
> -            m_pred[i].coeff = 1.0;
> -            m_pred[i].count = 1.0;
> -            m_pred[i].decay = 0.5;
> -            m_pred[i].offset = 0.0;
> -        }
> -        m_pred[0].coeff = m_pred[3].coeff = 0.75;
> +        m_lastPredictorReset = rce->encodeOrder;
> +        initFramePredictors();
>      }
> -    else if (m_sliceType != B_SLICE && !isframeAfterKeyframe)
> +    else if (m_sliceType != B_SLICE && !isRefFrameScenecut)
>          m_isSceneTransition = false;
>
> +    if (rce->encodeOrder < m_lastPredictorReset +
> m_param->frameNumThreads)
> +    {
> +        rce->rowPreds[0][0].count = 0;
> +    }
> +
>      rce->bLastMiniGopBFrame = curFrame->m_lowres.bLastMiniGopBFrame;
>      rce->bufferRate = m_bufferRate;
>      rce->rowCplxrSum = 0.0;
> @@ -2149,7 +2154,7 @@
>  {
>      int predType = rce->sliceType;
>      predType = rce->sliceType == B_SLICE && rce->keptAsRef ? 3 : predType;
> -    if (rce->lastSatd >= m_ncu)
> +    if (rce->lastSatd >= m_ncu && rce->encodeOrder >=
> m_lastPredictorReset)
>          updatePredictor(&m_pred[predType], x265_qp2qScale(rce->qpaRc),
> (double)rce->lastSatd, (double)bits);
>      if (!m_isVbv)
>          return;
> diff -r 69d55d4c53eb -r c44b32bc7c90 source/encoder/ratecontrol.h
> --- a/source/encoder/ratecontrol.h      Tue Sep 22 13:33:13 2015 +0530
> +++ b/source/encoder/ratecontrol.h      Tue Sep 22 13:40:07 2015 +0530
> @@ -173,6 +173,7 @@
>      int     m_numBframesInPattern;
>      bool    m_isPatternPresent;
>      bool    m_isSceneTransition;
> +    int     m_lastPredictorReset;
>
>      /* a common variable on which rateControlStart, rateControlEnd and
> rateControUpdateStats waits to
>       * sync the calls to these functions. For example
> @@ -257,6 +258,7 @@
>      void   checkAndResetABR(RateControlEntry* rce, bool isFrameDone);
>      double predictRowsSizeSum(Frame* pic, RateControlEntry* rce, double
> qpm, int32_t& encodedBits);
>      bool   initPass2();
> +    void   initFramePredictors();
>      double getDiffLimitedQScale(RateControlEntry *rce, double q);
>      double countExpectedBits();
>      bool   vbv2Pass(uint64_t allAvailableBits);
> _______________________________________________
> x265-devel mailing list
> x265-devel at videolan.org
> https://mailman.videolan.org/listinfo/x265-devel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.videolan.org/pipermail/x265-devel/attachments/20150928/32087dd2/attachment-0001.html>