[x265] [x265 Patch] Histogram Based Scene Cut Detection

Aruna Matheswaran aruna at multicorewareinc.com
Mon Nov 18 18:36:31 CET 2019


On Mon, Nov 18, 2019 at 12:20 PM Srikanth Kurapati <
srikanth.kurapati at multicorewareinc.com> wrote:

> # HG changeset patch
> # User Srikanth Kurapati <srikanth.kurapati at multicorewareinc.com>
> # Date 1573649311 -19800
> #      Wed Nov 13 18:18:31 2019 +0530
> # Node ID 40beab295ca274bf62cb2fd2e732da722d10eea3
> # Parent  04db2bfee5d628d931d1407355b909ac8ff1c898
> Histogram based scenecut detection
>
> This patch does the following.
> 1.Identifies scenecuts by thresholding against sad of edge and chroma
> histograms.
> 2.Add option "--hist-scenecut" to enable histogram based scenecut method.
> 3.Add option "--hist-threshold" to provide threshold for determining
> scene-cuts.
> 3.Optimizes frame duplication through reuse of sad for marking duplicate
> frames.
>
> diff -r 04db2bfee5d6 -r 40beab295ca2 doc/reST/cli.rst
> --- a/doc/reST/cli.rst Thu Oct 31 16:23:27 2019 +0530
> +++ b/doc/reST/cli.rst Wed Nov 13 18:18:31 2019 +0530
> @@ -1426,7 +1426,23 @@
>   This value represents the percentage difference between the inter cost
> and
>   intra cost of a frame used in scenecut detection. For example, a value
> of 5 indicates,
>   if the inter cost of a frame is greater than or equal to 95 percent of
> the intra cost of the frame,
> - then detect this frame as scenecut. Values between 5 and 15 are
> recommended. Default 5.
> + then detect this frame as scenecut. Values between 5 and 15 are
> recommended.
> + This value is evaluated only when --scenecut is enabled else it is
> ignored. Default 5.
> +
> +.. option:: --hist-scenecut, --no-hist-scenecut
> +
> + indicates that scenecuts need to be detected using luma edge and chroma
> histograms.
>
Case issue in "indicates".

> + option: `--hist-scenecut` enables scenecut detection using the
> histograms and disables the default scene cut algorithm.
> + option: `--no-hist-scenecut` disables histogram based scenecut algorithm.
> +
> + Note that if --hist-scenecut and --scenecut are enabled together the
> first choice of user is considered for processing.
> +
> +.. option:: --hist-threshold <0.0..2.0>
> +
> + This value represents the threshold for normalized SAD of edge
> histograms used in scenecut detection.
> + This requires hist-scenecut to be enabled. For example, a value of 0.2
> indicates that a frame with normalized SAD value
>
Add a link to hist-scenecut (option: `--hist-scenecut` )

> + greater than 0.2 against the previous frame as scenecut.
> + Default 0.01.
>
>  .. option:: --radl <integer>
>
> diff -r 04db2bfee5d6 -r 40beab295ca2 source/CMakeLists.txt
> --- a/source/CMakeLists.txt Thu Oct 31 16:23:27 2019 +0530
> +++ b/source/CMakeLists.txt Wed Nov 13 18:18:31 2019 +0530
> @@ -29,7 +29,7 @@
>  option(STATIC_LINK_CRT "Statically link C runtime for release builds" OFF)
>  mark_as_advanced(FPROFILE_USE FPROFILE_GENERATE NATIVE_BUILD)
>  # X265_BUILD must be incremented each time the public API is changed
> -set(X265_BUILD 182)
> +set(X265_BUILD 183)
>  configure_file("${PROJECT_SOURCE_DIR}/x265.def.in"
>                 "${PROJECT_BINARY_DIR}/x265.def")
>  configure_file("${PROJECT_SOURCE_DIR}/x265_config.h.in"
> diff -r 04db2bfee5d6 -r 40beab295ca2 source/common/common.h
> --- a/source/common/common.h Thu Oct 31 16:23:27 2019 +0530
> +++ b/source/common/common.h Wed Nov 13 18:18:31 2019 +0530
> @@ -129,12 +129,16 @@
>  typedef uint64_t sum2_t;
>  typedef uint64_t pixel4;
>  typedef int64_t  ssum2_t;
> +#define HISTOGRAM_BINS 1024
> +#define SHIFT 1
>  #else
>  typedef uint8_t  pixel;
>  typedef uint16_t sum_t;
>  typedef uint32_t sum2_t;
>  typedef uint32_t pixel4;
>  typedef int32_t  ssum2_t; // Signed sum
> +#define HISTOGRAM_BINS 256
> +#define SHIFT 0
>  #endif // if HIGH_BIT_DEPTH
>
>  #if X265_DEPTH < 10
> diff -r 04db2bfee5d6 -r 40beab295ca2 source/common/param.cpp
> --- a/source/common/param.cpp Thu Oct 31 16:23:27 2019 +0530
> +++ b/source/common/param.cpp Wed Nov 13 18:18:31 2019 +0530
> @@ -167,6 +167,8 @@
>      param->bFrameAdaptive = X265_B_ADAPT_TRELLIS;
>      param->bBPyramid = 1;
>      param->scenecutThreshold = 40; /* Magic number pulled in from x264 */
> +    param->edgeTransitionThreshold = 0.01;
> +    param->bHistBasedSceneCut = false;
>      param->lookaheadSlices = 8;
>      param->lookaheadThreads = 0;
>      param->scenecutBias = 5.0;
> @@ -572,6 +574,7 @@
>              param->bframes = 0;
>              param->lookaheadDepth = 0;
>              param->scenecutThreshold = 0;
> +            param->bHistBasedSceneCut = false;
>              param->rc.cuTree = 0;
>              param->frameNumThreads = 1;
>          }
> @@ -614,7 +617,7 @@
>      return 0;
>  }
>
> -static int x265_atobool(const char* str, bool& bError)
> +static bool x265_atobool(const char* str, bool& bError)
>  {
>      if (!strcmp(str, "1") ||
>          !strcmp(str, "true") ||
> @@ -764,6 +767,7 @@
>      bool bNameWasBool = false;
>      bool bValueWasNull = !value;
>      bool bExtraParams = false;
> +    static int scenecutChoice = -1;
>
Is this necessary? Can you make the latest option set to take effect?

>      char nameBuf[64];
>      static int count;
>
> @@ -920,11 +924,16 @@
>      OPT("lookahead-slices") p->lookaheadSlices = atoi(value);
>      OPT("scenecut")
>      {
> -        p->scenecutThreshold = atobool(value);
> -        if (bError || p->scenecutThreshold)
> +        if (scenecutChoice == -1)
>          {
> -            bError = false;
> -            p->scenecutThreshold = atoi(value);
> +            p->scenecutThreshold = atobool(value);
> +            if (bError || p->scenecutThreshold)
> +            {
> +                bError = false;
> +                p->scenecutThreshold = atoi(value);
> +                p->bHistBasedSceneCut = false;
> +                scenecutChoice = 0;
> +            }
>          }
>      }
>      OPT("temporal-layers") p->bEnableTemporalSubLayers = atobool(value);
> @@ -1191,6 +1200,46 @@
>          OPT("opt-ref-list-length-pps") p->bOptRefListLengthPPS =
> atobool(value);
>          OPT("multi-pass-opt-rps") p->bMultiPassOptRPS = atobool(value);
>          OPT("scenecut-bias") p->scenecutBias = atof(value);
> +        OPT("hist-scenecut")
> +        {
> +            if (scenecutChoice == -1)
> +            {
> +                p->bHistBasedSceneCut = atobool(value);
> +                if (bError)
> +                {
> +                    bError = false;
> +                    p->bHistBasedSceneCut = false;
> +                }
> +                if (p->bHistBasedSceneCut)
> +                {
> +                    bError = false;
> +                    p->scenecutThreshold = 0;
> +                    scenecutChoice = 1;
> +                }
> +            }
> +            else
> +            {
> +                p->bHistBasedSceneCut = atobool(value);
> +                p->bHistBasedSceneCut = false;
> +            }
> +        }
> +        OPT("hist-threshold")
> +        {
> +            if (p->bHistBasedSceneCut)
>
Will this work if --hist-scenecut is set after --hist-threshold in the CLI?

> +            {
> +                p->edgeTransitionThreshold = atof(value);
> +                if (bError)
> +                {
> +                    bError = false;
> +                    p->edgeTransitionThreshold = 0.01;
> +                    x265_log(p, X265_LOG_INFO, "Using  default threshold
> %.2lf for scene cut detection\n", p->edgeTransitionThreshold);
> +                }
> +            }
> +            else
> +            {
> +                x265_log(p, X265_LOG_WARNING, "Histogram based scene cut
> detection not enabled\n", p->edgeTransitionThreshold);
> +            }
> +        }
>          OPT("lookahead-threads") p->lookaheadThreads = atoi(value);
>          OPT("opt-cu-delta-qp") p->bOptCUDeltaQP = atobool(value);
>          OPT("multi-pass-opt-analysis") p->analysisMultiPassRefine =
> atobool(value);
> @@ -1631,8 +1680,16 @@
>            "Valid Logging level -1:none 0:error 1:warning 2:info 3:debug
> 4:full");
>      CHECK(param->scenecutThreshold < 0,
>            "scenecutThreshold must be greater than 0");
> -    CHECK(param->scenecutBias < 0 || 100 < param->scenecutBias,
> -           "scenecut-bias must be between 0 and 100");
> +    if (param->scenecutThreshold)
> +    {
> +        CHECK(param->scenecutBias < 0 || 100 < param->scenecutBias,
> +            "scenecut-bias must be between 0 and 100");
> +    }
> +    else if (param->bHistBasedSceneCut)
> +    {
> +        CHECK(param->edgeTransitionThreshold < 0.0 || 2.0 <
> param->edgeTransitionThreshold,
> +            "hist-threshold must be between 0.0 and 2.0");
> +    }
>      CHECK(param->radl < 0 || param->radl > param->bframes,
>            "radl must be between 0 and bframes");
>      CHECK(param->rdPenalty < 0 || param->rdPenalty > 2,
> @@ -1792,9 +1849,13 @@
>          x265_log(param, X265_LOG_INFO, "ME / range / subpel / merge
>   : %s / %d / %d / %d\n",
>              x265_motion_est_names[param->searchMethod],
> param->searchRange, param->subpelRefine, param->maxNumMergeCand);
>
> -    if (param->keyframeMax != INT_MAX || param->scenecutThreshold)
> -        x265_log(param, X265_LOG_INFO, "Keyframe min / max / scenecut /
> bias: %d / %d / %d / %.2lf\n", param->keyframeMin, param->keyframeMax,
> param->scenecutThreshold, param->scenecutBias * 100);
> -    else
> +    if (param->scenecutThreshold && param->keyframeMax != INT_MAX)
> +        x265_log(param, X265_LOG_INFO, "Keyframe min / max / scenecut /
> bias  : %d / %d / %d / %.2lf \n",
> +                 param->keyframeMin, param->keyframeMax,
> param->scenecutThreshold, param->scenecutBias * 100);
> +    else if (param->bHistBasedSceneCut && param->keyframeMax != INT_MAX)
> +        x265_log(param, X265_LOG_INFO, "Keyframe min / max / scenecut /
> edge threshold  : %d / %d / %d / %.2lf\n",
> +                 param->keyframeMin, param->keyframeMax,
> param->bHistBasedSceneCut, param->edgeTransitionThreshold);
> +    else if (param->keyframeMax == INT_MAX)
>          x265_log(param, X265_LOG_INFO, "Keyframe min / max / scenecut
>   : disabled\n");
>
>      if (param->cbQpOffset || param->crQpOffset)
> @@ -1961,6 +2022,8 @@
>      s += sprintf(s, " rc-lookahead=%d", p->lookaheadDepth);
>      s += sprintf(s, " lookahead-slices=%d", p->lookaheadSlices);
>      s += sprintf(s, " scenecut=%d", p->scenecutThreshold);
> +    s += sprintf(s, " hist-scenecut=%d", p->bHistBasedSceneCut);
> +    s += sprintf(s, " hist-threshold=%.2f", p->edgeTransitionThreshold);
>      s += sprintf(s, " radl=%d", p->radl);
>      BOOL(p->bEnableHRDConcatFlag, "splice");
>      BOOL(p->bIntraRefresh, "intra-refresh");
> @@ -2108,6 +2171,8 @@
>      BOOL(p->bOptRefListLengthPPS, "opt-ref-list-length-pps");
>      BOOL(p->bMultiPassOptRPS, "multi-pass-opt-rps");
>      s += sprintf(s, " scenecut-bias=%.2f", p->scenecutBias);
> +    s += sprintf(s, " hist-threshold=%.2f", p->edgeTransitionThreshold);
> +
>

Added twice; Please remove one.
>
     BOOL(p->bOptCUDeltaQP, "opt-cu-delta-qp");
>      BOOL(p->bAQMotion, "aq-motion");
>      BOOL(p->bEmitHDRSEI, "hdr");
> @@ -2261,6 +2326,7 @@
>      dst->lookaheadSlices = src->lookaheadSlices;
>      dst->lookaheadThreads = src->lookaheadThreads;
>      dst->scenecutThreshold = src->scenecutThreshold;
> +    dst->bHistBasedSceneCut = src->bHistBasedSceneCut;
>      dst->bIntraRefresh = src->bIntraRefresh;
>      dst->maxCUSize = src->maxCUSize;
>      dst->minCUSize = src->minCUSize;
> @@ -2420,6 +2486,7 @@
>      dst->bOptRefListLengthPPS = src->bOptRefListLengthPPS;
>      dst->bMultiPassOptRPS = src->bMultiPassOptRPS;
>      dst->scenecutBias = src->scenecutBias;
> +    dst->edgeTransitionThreshold = src->edgeTransitionThreshold;
>      dst->gopLookahead = src->lookaheadDepth;
>      dst->bOptCUDeltaQP = src->bOptCUDeltaQP;
>      dst->analysisMultiPassDistortion = src->analysisMultiPassDistortion;
> diff -r 04db2bfee5d6 -r 40beab295ca2 source/encoder/encoder.cpp
> --- a/source/encoder/encoder.cpp Thu Oct 31 16:23:27 2019 +0530
> +++ b/source/encoder/encoder.cpp Wed Nov 13 18:18:31 2019 +0530
> @@ -130,12 +130,17 @@
>  #if SVT_HEVC
>      m_svtAppData = NULL;
>  #endif
> -
>      m_prevTonemapPayload.payload = NULL;
>      m_startPoint = 0;
>      m_saveCTUSize = 0;
> +    m_edgePic = NULL;
> +    m_edgeHistThreshold = 0;
> +    m_chromaHistThreshold = 0.0;
> +    m_scaledEdgeThreshold = 0.0;
> +    m_scaledChromaThreshold = 0.0;
>      m_zoneIndex = 0;
>  }
> +
>  inline char *strcatFilename(const char *input, const char *suffix)
>  {
>      char *output = X265_MALLOC(char, strlen(input) + strlen(suffix) + 1);
> @@ -210,6 +215,24 @@
>          }
>      }
>
> +    if (m_param->bHistBasedSceneCut)
> +    {
> +        for (int i = 0; i < x265_cli_csps[m_param->internalCsp].planes;
> i++)
> +        {
> +            m_planeSizes[i] = m_param->sourceWidth *
> m_param->sourceHeight >> x265_cli_csps[m_param->internalCsp].height[i];
> +        }
> +        uint32_t pixelbytes = m_param->sourceBitDepth > 8 ? 2 : 1;
> +        m_edgePic = X265_MALLOC(pixel, m_planeSizes[0]*pixelbytes);
>
Indentation issue // m_planeSizes[0]*pixelbytes

> +        double strengthFactor = 2.0;
>
Replace the constant with a macro

> +        m_edgeHistThreshold = m_param->edgeTransitionThreshold;
> +        m_chromaHistThreshold = m_edgeHistThreshold * 10.0;
> +        m_chromaHistThreshold = x265_min(m_chromaHistThreshold,
> MAX_SCENECUT_THRESHOLD);
> +        m_scaledEdgeThreshold = m_edgeHistThreshold * strengthFactor;
> +        m_scaledEdgeThreshold = x265_min(m_scaledEdgeThreshold,
> MAX_SCENECUT_THRESHOLD);
> +        m_scaledChromaThreshold = m_chromaHistThreshold * strengthFactor;
> +        m_scaledChromaThreshold = x265_min(m_scaledChromaThreshold,
> MAX_SCENECUT_THRESHOLD);
> +    }
> +
>      // Do not allow WPP if only one row or fewer than 3 columns, it is
> pointless and unstable
>      if (rows == 1 || cols < 3)
>      {
> @@ -854,6 +877,12 @@
>          }
>      }
>
> +    if (m_param->bHistBasedSceneCut)
> +    {
> +        if(m_edgePic != NULL)
> +           X265_FREE_ZERO(m_edgePic);
> +    }
> +
>      for (int i = 0; i < m_param->frameNumThreads; i++)
>      {
>          if (m_frameEncoder[i])
> @@ -1313,6 +1342,141 @@
>      dest->planes[2] = (char*)dest->planes[1] + src->stride[1] *
> (src->height >> x265_cli_csps[src->colorSpace].height[1]);
>  }
>
> +bool Encoder::computeHistograms(x265_picture *pic)
> +{
> +    pixel *src = (pixel*)pic->planes[0];
> +    size_t bufSize = sizeof(pixel) * m_planeSizes[0];
> +    int32_t planeCount = x265_cli_csps[m_param->internalCsp].planes;
> +    int32_t numBytes = m_param->sourceBitDepth > 8 ? 2 : 1;
> +    memset(m_edgePic, 0, bufSize*numBytes);
> +
> +    if (!computeEdge(m_edgePic, src, NULL, pic->width, pic->height,
> pic->width, false))
> +    {
> +       x265_log(m_param, X265_LOG_ERROR, "Failed edge computation!");
> +       return false;
> +    }
> +
> +    pixel pixelVal;
> +    int64_t size = pic->height * (pic->stride[0] >> SHIFT);
> +    int32_t *edgeHist = m_curEdgeHist;
> +    memset(edgeHist, 0, 2 * sizeof(int32_t));
> +    for (int64_t i = 0; i < size; i++)
> +    {
> +        if (!m_edgePic[i])
> +           edgeHist[0]++;
> +        else
> +           edgeHist[1]++;
> +    }
> +
> +    /*U Histogram Calculation*/
> +    int32_t HeightL = (pic->height >>
> x265_cli_csps[pic->colorSpace].height[1]);
> +    size = HeightL * (pic->stride[1] >> SHIFT);
> +    int32_t *uHist = m_curUVHist[0];
> +    pixel *chromaPlane = (pixel *)pic->planes[1];
>
Encoder crashes with X265_CSP_I400 input; You need to check the CSP type
before accessing the UV planes.

> +
>
+    memset(uHist, 0, HISTOGRAM_BINS * sizeof(int32_t));
> +
> +    for (int64_t i = 0; i < size; i++)
> +    {
> +        pixelVal = chromaPlane[i];
> +        uHist[pixelVal]++;
> +    }
> +
> +    /*V Histogram Calculation */
> +    if (planeCount == 3)
>
+    {
> +        pixelVal = 0;
> +        int32_t heightV = (pic->height >>
> x265_cli_csps[pic->colorSpace].height[2]);
> +        size = heightV * (pic->stride[2] >> SHIFT);
> +        int32_t *vHist = m_curUVHist[1];
> +        chromaPlane = (pixel *)pic->planes[2];
> +
> +        memset(vHist, 0, HISTOGRAM_BINS * sizeof(int32_t));
> +        for (int64_t i = 0; i < size; i++)
> +        {
> +            pixelVal = chromaPlane[i];
> +            vHist[pixelVal]++;
> +        }
> +        for (int i = 0; i < HISTOGRAM_BINS; i++)
> +        {
> +            m_curMaxUVHist[i] = x265_max(uHist[i],vHist[i]);
>
Intendation issue

> +        }
> +    }
> +    else
> +    {   /* in case of bi planar color space */
> +
>  memcpy(m_curMaxUVHist,m_curUVHist[0],HISTOGRAM_BINS*sizeof(int32_t));
>
Intendation issue

> +    }
> +
> +    return true;
> +}
> +
> +void Encoder::computeHistogramSAD(double *maxUVNormalizedSad, double
> *edgeNormalizedSad, int curPoc)
> +{
> +
> +    if (curPoc == 0)
> +    {  /* first frame is scenecut by default no sad computation for the
> same. */
> +       *maxUVNormalizedSad = 0.0;
> +       *edgeNormalizedSad  = 0.0;
> +    }
> +    else
> +    {
> +        /* compute sum of absolute difference of normalized histogram
> bins for maxUV and edge histograms. */
> +        int32_t edgefreqDiff = 0;
> +        int32_t maxUVfreqDiff = 0;
> +        double  edgeProbabilityDiff = 0;
> +
> +        for (int j = 0; j < HISTOGRAM_BINS; j++)
> +        {
> +            if (j < 2 )
>
indentation issue

> +            {
> +               edgefreqDiff = abs(m_curEdgeHist[j] - m_prevEdgeHist[j]);
> +               edgeProbabilityDiff = (double) edgefreqDiff /
> m_planeSizes[0];
> +               *edgeNormalizedSad += edgeProbabilityDiff;
> +            }
> +            maxUVfreqDiff = abs(m_curMaxUVHist[j] - m_prevMaxUVHist[j]);
> +            *maxUVNormalizedSad += (double)maxUVfreqDiff /
> m_planeSizes[2];
> +        }
> +    }
> +
> +    /* store histograms of previous frame for reference */
> +    size_t bufsize = HISTOGRAM_BINS * sizeof(int32_t);
> +    memcpy(m_prevMaxUVHist, m_curMaxUVHist, bufsize);
> +    memcpy(m_prevEdgeHist, m_curEdgeHist, 2*sizeof(int32_t));
>
indentation issue

> +
> +}
> +
> +void Encoder::findSceneCuts(x265_picture * pic, bool& bDup, double
> maxUVSad, double edgeSad)
> +{
> +    pic->frameData.bScenecut = false;
> +
> +    if (pic->poc == 0)
> +    {
> +       /* for first frame */
> +       pic->frameData.bScenecut = false;
> +       bDup = false;
> +    }
> +    else
> +    {
> +        if (edgeSad == 0.0 && maxUVSad == 0.0)
> +        {
> +           bDup = true;
> +        }
> +        else if (edgeSad > m_edgeHistThreshold && maxUVSad >=
> m_chromaHistThreshold)
> +        {
> +             pic->frameData.bScenecut = true;
> +             bDup = false;
> +        }
> +        else if (edgeSad > m_scaledEdgeThreshold || maxUVSad >=
> m_scaledChromaThreshold)
> +        {
> +             pic->frameData.bScenecut = true;
> +             bDup = false;
> +        }
> +    }
> +
> +    if (pic->frameData.bScenecut)
> +       x265_log(m_param, X265_LOG_DEBUG, "scene cut at %d \n",pic->poc);
>
indentation issue

> +}
> +
>  /**
>   * Feed one new input frame into the encoder, get one frame out. If
> pic_in is
>   * NULL, a flush condition is implied and pic_in must be NULL for all
> subsequent
> @@ -1339,6 +1503,8 @@
>      const x265_picture* inputPic = NULL;
>      static int written = 0, read = 0;
>      bool dontRead = false;
> +    bool bdropFrame = false;
> +    bool dropflag = false;
>
>      if (m_exportedPic)
>      {
> @@ -1350,6 +1516,17 @@
>      }
>      if ((pic_in && (!m_param->chunkEnd || (m_encodedFrameNum <
> m_param->chunkEnd))) || (m_param->bEnableFrameDuplication && !pic_in &&
> (read < written)))
>      {
> +        if (m_param->bHistBasedSceneCut && pic_in)
> +        {
> +            x265_picture *pic = (x265_picture *) pic_in;
> +            if (computeHistograms(pic))
> +            {
> +               double  maxUVSad = 0.0, edgeSad = 0.0;
> +               computeHistogramSAD(&maxUVSad, &edgeSad,pic_in->poc);
>
indentation issue.

> +               findSceneCuts(pic, bdropFrame, maxUVSad, edgeSad);
> +            }
> +        }
> +
>          if ((m_param->bEnableFrameDuplication && !pic_in && (read <
> written)))
>              dontRead = true;
>          else
> @@ -1393,9 +1570,27 @@
>                      written++;
>                  }
>
> -                psnrWeight = ComputePSNR(m_dupBuffer[0]->dupPic,
> m_dupBuffer[1]->dupPic, m_param);
> -
> -                if (psnrWeight >= m_param->dupThreshold)
> +                if (m_param->bEnableFrameDuplication &&
> m_param->bHistBasedSceneCut)
> +                {
> +                    if (!bdropFrame &&
> m_dupBuffer[1]->dupPic->frameData.bScenecut == false)
> +                    {
> +                       psnrWeight = ComputePSNR(m_dupBuffer[0]->dupPic,
> m_dupBuffer[1]->dupPic, m_param);
> +                       if (psnrWeight >= m_param->dupThreshold)
> +                          dropflag = true;
> +                    }
> +                    else
> +                    {
> +                       dropflag = true;
> +                    }
> +                }
> +                else if (m_param->bEnableFrameDuplication)
> +                {
> +                    psnrWeight = ComputePSNR(m_dupBuffer[0]->dupPic,
> m_dupBuffer[1]->dupPic, m_param);
> +                    if (psnrWeight >= m_param->dupThreshold)
> +                       dropflag = true;
> +                }
> +
> +                if (dropflag)
>                  {
>                      if (m_dupBuffer[0]->bDup)
>                      {
> @@ -1498,6 +1693,10 @@
>          inFrame->m_poc       = ++m_pocLast;
>          inFrame->m_userData  = inputPic->userData;
>          inFrame->m_pts       = inputPic->pts;
> +        if (m_param->bHistBasedSceneCut)
> +        {
> +           inFrame->m_lowres.bScenecut = inputPic->frameData.bScenecut;
> +        }
>          inFrame->m_forceqp   = inputPic->forceqp;
>          inFrame->m_param     = (m_reconfigure || m_reconfigureRc) ?
> m_latestParam : m_param;
>          inFrame->m_picStruct = inputPic->picStruct;
> @@ -3209,6 +3408,7 @@
>           * adaptive I frame placement */
>          p->keyframeMax = INT_MAX;
>          p->scenecutThreshold = 0;
> +        p->bHistBasedSceneCut = 0;
>      }
>      else if (p->keyframeMax <= 1)
>      {
> @@ -3222,6 +3422,7 @@
>          p->lookaheadDepth = 0;
>          p->bframes = 0;
>          p->scenecutThreshold = 0;
> +        p->bHistBasedSceneCut = 0;
>          p->bFrameAdaptive = 0;
>          p->rc.cuTree = 0;
>          p->bEnableWeightedPred = 0;
> @@ -3881,6 +4082,17 @@
>              m_param->searchMethod = m_param->hmeSearchMethod[2];
>          }
>      }
> +
> +    if (p->scenecutThreshold && p->edgeTransitionThreshold != 0.01)
> +    {
>
float point comparison; might result in rounding errors.
Also, why are you checking  p->edgeTransitionThreshold when naive scenecut
algorithm is enabled?

> +       x265_log(p, X265_LOG_WARNING, "using default scenecut-bias %.2lf
> for scene cut detection\n",p->scenecutBias);
> +    }
> +    else if (p->bHistBasedSceneCut && p->edgeTransitionThreshold == 0.0)
>
float point comparison; might result in rounding errors.

> +    {
> +         p->edgeTransitionThreshold = 0.01;
> +         x265_log(p, X265_LOG_WARNING, "using  default threshold %.2lf
> for scene cut detection\n", p->edgeTransitionThreshold);
> +    }
> +
>  }
>
>  void Encoder::readAnalysisFile(x265_analysis_data* analysis, int curPoc,
> const x265_picture* picIn, int paramBytes)
> diff -r 04db2bfee5d6 -r 40beab295ca2 source/encoder/encoder.h
> --- a/source/encoder/encoder.h Thu Oct 31 16:23:27 2019 +0530
> +++ b/source/encoder/encoder.h Wed Nov 13 18:18:31 2019 +0530
> @@ -156,7 +156,6 @@
>      bool bDup;
>  };
>
> -
>  class FrameEncoder;
>  class DPB;
>  class Lookahead;
> @@ -164,6 +163,8 @@
>  class ThreadPool;
>  class FrameData;
>
> +#define MAX_SCENECUT_THRESHOLD 2.0
> +
>  class Encoder : public x265_encoder
>  {
>  public:
> @@ -228,7 +229,7 @@
>      bool               m_reconfigureRc;
>      bool               m_reconfigureZone;
>
> -    int               m_saveCtuDistortionLevel;
> +    int                m_saveCtuDistortionLevel;
>
>      /* Begin intra refresh when one not in progress or else begin one as
> soon as the current
>       * one is done. Requires bIntraRefresh to be set.*/
> @@ -245,11 +246,24 @@
>      Lock               m_rpsInSpsLock;
>      int                m_rpsInSpsCount;
>      /* For HDR*/
> -    double                m_cB;
> -    double                m_cR;
> +    double             m_cB;
> +    double             m_cR;
> +
> +    int                m_bToneMap; // Enables tone-mapping
> +    int                m_enableNal;
>
> -    int                     m_bToneMap; // Enables tone-mapping
> -    int                     m_enableNal;
> +    /* For histogram based scene-cut detection */
> +    pixel*             m_edgePic;
> +    int32_t            m_curUVHist[2][HISTOGRAM_BINS];
> +    int32_t            m_curMaxUVHist[HISTOGRAM_BINS];
> +    int32_t            m_prevMaxUVHist[HISTOGRAM_BINS];
> +    int32_t            m_curEdgeHist[2];
> +    int32_t            m_prevEdgeHist[2];
> +    uint32_t           m_planeSizes[3];
> +    double             m_edgeHistThreshold;
> +    double             m_chromaHistThreshold;
> +    double             m_scaledEdgeThreshold;
> +    double             m_scaledChromaThreshold;
>
>  #ifdef ENABLE_HDR10_PLUS
>      const hdr10plus_api     *m_hdr10plus_api;
> @@ -355,6 +369,10 @@
>
>      void copyPicture(x265_picture *dest, const x265_picture *src);
>
> +    bool computeHistograms(x265_picture *pic);
> +    void computeHistogramSAD(double *maxUVNormalizedSAD, double
> *edgeNormalizedSAD, int curPoc);
> +    void findSceneCuts(x265_picture * pic, bool& bDup, double
> m_maxUVSADVal, double m_edgeSADVal);
> +
>      void initRefIdx();
>      void analyseRefIdx(int *numRefIdx);
>      void updateRefIdx();
> diff -r 04db2bfee5d6 -r 40beab295ca2 source/encoder/ratecontrol.cpp
> --- a/source/encoder/ratecontrol.cpp Thu Oct 31 16:23:27 2019 +0530
> +++ b/source/encoder/ratecontrol.cpp Wed Nov 13 18:18:31 2019 +0530
> @@ -508,6 +508,7 @@
>                  CMP_OPT_FIRST_PASS("open-gop", m_param->bOpenGOP);
>                  CMP_OPT_FIRST_PASS(" keyint", m_param->keyframeMax);
>                  CMP_OPT_FIRST_PASS("scenecut",
> m_param->scenecutThreshold);
> +                CMP_OPT_FIRST_PASS("hist-threshold",
> m_param->edgeTransitionThreshold);
>                  CMP_OPT_FIRST_PASS("intra-refresh",
> m_param->bIntraRefresh);
>                  if (m_param->bMultiPassOptRPS)
>                  {
> @@ -1200,6 +1201,7 @@
>              m_param->rc.bStatRead = 0;
>              m_param->bFrameAdaptive = 0;
>              m_param->scenecutThreshold = 0;
> +            m_param->bHistBasedSceneCut = false;
>              m_param->rc.cuTree = 0;
>              if (m_param->bframes > 1)
>                  m_param->bframes = 1;
> @@ -2284,7 +2286,7 @@
>      if (m_isVbv && m_currentSatd > 0 && curFrame)
>      {
>          if (m_param->lookaheadDepth || m_param->rc.cuTree ||
> -            m_param->scenecutThreshold ||
> +            (m_param->scenecutThreshold || m_param->bHistBasedSceneCut) ||
>              (m_param->bFrameAdaptive && m_param->bframes))
>          {
>             /* Lookahead VBV: If lookahead is done, raise the quantizer as
> necessary
> diff -r 04db2bfee5d6 -r 40beab295ca2 source/encoder/slicetype.cpp
> --- a/source/encoder/slicetype.cpp Thu Oct 31 16:23:27 2019 +0530
> +++ b/source/encoder/slicetype.cpp Wed Nov 13 18:18:31 2019 +0530
> @@ -85,6 +85,69 @@
>
>  } // end anonymous namespace
>
> +namespace X265_NS {
> +
> +bool computeEdge(pixel *edgePic, pixel *refPic, pixel *edgeTheta,
> intptr_t stride, int height, int width, bool bcalcTheta)
> +{
> +    intptr_t rowOne = 0, rowTwo = 0, rowThree = 0, colOne = 0, colTwo =
> 0, colThree = 0;
> +    intptr_t middle = 0, topLeft = 0, topRight = 0, bottomLeft = 0,
> bottomRight = 0;
> +
> +    const int startIndex = 1;
> +
> +    if (!edgePic || !refPic || (!edgeTheta && bcalcTheta))
> +    {
> +        return false;
> +    }
> +    else
> +    {
> +        float gradientH = 0, gradientV = 0, radians = 0, theta = 0;
> +        float gradientMagnitude = 0;
> +        pixel blackPixel = 0;
> +
> +        //Applying Sobel filter expect for border pixels
> +        height = height - startIndex;
> +        width = width - startIndex;
> +        for (int rowNum = startIndex; rowNum < height; rowNum++)
> +        {
> +            rowTwo = rowNum * stride;
> +            rowOne = rowTwo - stride;
> +            rowThree = rowTwo + stride;
> +
> +            for (int colNum = startIndex; colNum < width; colNum++)
> +            {
> +
> +                /* Horizontal and vertical gradients
> +                [ -3   0   3 ]        [-3   -10  -3 ]
> +            gH =[ -10  0   10]   gV = [ 0    0    0 ]
> +                [ -3   0   3 ]        [ 3    10   3 ] */
> +
> +                colTwo = colNum;
> +                colOne = colTwo - startIndex;
> +                colThree = colTwo + startIndex;
> +                middle = rowTwo + colTwo;
> +                topLeft = rowOne + colOne;
> +                topRight = rowOne + colThree;
> +                bottomLeft = rowThree + colOne;
> +                bottomRight = rowThree + colThree;
> +                gradientH = (float)(-3 * refPic[topLeft] + 3 *
> refPic[topRight] - 10 * refPic[rowTwo + colOne] + 10 * refPic[rowTwo +
> colThree] - 3 * refPic[bottomLeft] + 3 * refPic[bottomRight]);
> +                gradientV = (float)(-3 * refPic[topLeft] - 10 *
> refPic[rowOne + colTwo] - 3 * refPic[topRight] + 3 * refPic[bottomLeft] +
> 10 * refPic[rowThree + colTwo] + 3 * refPic[bottomRight]);
> +                gradientMagnitude = sqrtf(gradientH * gradientH +
> gradientV * gradientV);
> +                if(bcalcTheta)
> +                  {
> +                    edgeTheta[middle] = 0;
> +                    radians = atan2(gradientV, gradientH);
> +                    theta = (float)((radians * 180) / PI);
> +                    if (theta < 0)
> +                       theta = 180 + theta;
> +                    edgeTheta[middle] = (pixel)theta;
> +                  }
> +                edgePic[middle] = (pixel)(gradientMagnitude >=
> edgeThreshold ? edgeThreshold : blackPixel);
> +            }
> +        }
> +        return true;
> +    }
> +}
> +
>  void edgeFilter(Frame *curFrame, x265_param* param)
>  {
>      int height = curFrame->m_fencPic->m_picHeight;
> @@ -114,6 +177,7 @@
>      //Applying Gaussian filter on the picture
>      src = (pixel*)curFrame->m_fencPic->m_picOrg[0];
>      refPic = curFrame->m_gaussianPic + curFrame->m_fencPic->m_lumaMarginY
> * stride + curFrame->m_fencPic->m_lumaMarginX;
> +    edgePic = curFrame->m_edgePic + curFrame->m_fencPic->m_lumaMarginY *
> stride + curFrame->m_fencPic->m_lumaMarginX;
>      pixel pixelValue = 0;
>
>      for (int rowNum = 0; rowNum < height; rowNum++)
> @@ -146,51 +210,8 @@
>          }
>      }
>
> -#if HIGH_BIT_DEPTH //10-bit build
> -    float threshold = 1023;
> -    pixel whitePixel = 1023;
> -#else
> -    float threshold = 255;
> -    pixel whitePixel = 255;
> -#endif
> -#define PI 3.14159265
> -
> -    float gradientH = 0, gradientV = 0, radians = 0, theta = 0;
> -    float gradientMagnitude = 0;
> -    pixel blackPixel = 0;
> -    edgePic = curFrame->m_edgePic + curFrame->m_fencPic->m_lumaMarginY *
> stride + curFrame->m_fencPic->m_lumaMarginX;
> -    //Applying Sobel filter on the gaussian filtered picture
> -    for (int rowNum = 0; rowNum < height; rowNum++)
> -    {
> -        for (int colNum = 0; colNum < width; colNum++)
> -        {
> -            edgeTheta[(rowNum*stride) + colNum] = 0;
> -            if ((rowNum != 0) && (colNum != 0) && (rowNum != height - 1)
> && (colNum != width - 1)) //Ignoring the border pixels of the picture
> -            {
> -                /*Horizontal and vertical gradients
> -                       [ -3   0   3 ]        [-3   -10  -3 ]
> -                  gH = [ -10  0   10]   gV = [ 0    0    0 ]
> -                       [ -3   0   3 ]        [ 3    10   3 ]*/
> -
> -                const intptr_t rowOne = (rowNum - 1)*stride, colOne =
> colNum -1;
> -                const intptr_t rowTwo = rowNum * stride, colTwo = colNum;
> -                const intptr_t rowThree = (rowNum + 1)*stride, colThree =
> colNum + 1;
> -                const intptr_t index = (rowNum*stride) + colNum;
> -
> -                gradientH = (float)(-3 * refPic[rowOne + colOne] + 3 *
> refPic[rowOne + colThree] - 10 * refPic[rowTwo + colOne] + 10 *
> refPic[rowTwo + colThree] - 3 * refPic[rowThree + colOne] + 3 *
> refPic[rowThree + colThree]);
> -                gradientV = (float)(-3 * refPic[rowOne + colOne] - 10 *
> refPic[rowOne + colTwo] - 3 * refPic[rowOne + colThree] + 3 *
> refPic[rowThree + colOne] + 10 * refPic[rowThree + colTwo] + 3 *
> refPic[rowThree + colThree]);
> -
> -                gradientMagnitude = sqrtf(gradientH * gradientH +
> gradientV * gradientV);
> -                radians = atan2(gradientV, gradientH);
> -                theta = (float)((radians * 180) / PI);
> -                if (theta < 0)
> -                    theta = 180 + theta;
> -                edgeTheta[(rowNum*stride) + colNum] = (pixel)theta;
> -
> -                edgePic[index] = gradientMagnitude >= threshold ?
> whitePixel : blackPixel;
> -            }
> -        }
> -    }
> +    if(!computeEdge(edgePic, refPic, edgeTheta, stride, height, width,
> true))
> +        x265_log(NULL, X265_LOG_ERROR, "Failed edge computation!");
>  }
>
>  //Find the angle of a block by averaging the pixel angles
> @@ -1471,7 +1492,7 @@
>
>      if (m_lastNonB && !m_param->rc.bStatRead &&
>          ((m_param->bFrameAdaptive && m_param->bframes) ||
> -         m_param->rc.cuTree || m_param->scenecutThreshold ||
> +         m_param->rc.cuTree || m_param->scenecutThreshold ||
> m_param->bHistBasedSceneCut ||
>           (m_param->lookaheadDepth && m_param->rc.vbvBufferSize)))
>      {
>          slicetypeAnalyse(frames, false);
> @@ -1971,10 +1992,15 @@
>
>      int numBFrames = 0;
>      int numAnalyzed = numFrames;
> -    bool isScenecut = scenecut(frames, 0, 1, true, origNumFrames);
> +    bool isScenecut = false;
>
>      /* When scenecut threshold is set, use scenecut detection for I frame
> placements */
> -    if (m_param->scenecutThreshold && isScenecut)
> +    if (m_param->scenecutThreshold)
> +        isScenecut = scenecut(frames, 0, 1, true, origNumFrames);
> +    else if (m_param->bHistBasedSceneCut)
> +        isScenecut = frames[1]->bScenecut;
> +
> +    if (isScenecut)
>      {
>          frames[1]->sliceType = X265_TYPE_I;
>          return;
> @@ -1985,14 +2011,17 @@
>          m_extendGopBoundary = false;
>          for (int i = m_param->bframes + 1; i < origNumFrames; i +=
> m_param->bframes + 1)
>          {
> -            scenecut(frames, i, i + 1, true, origNumFrames);
> +            if (m_param->scenecutThreshold)
> +               scenecut(frames, i, i + 1, true, origNumFrames);
> +
>              for (int j = i + 1; j <= X265_MIN(i + m_param->bframes + 1,
> origNumFrames); j++)
>              {
> -                if (frames[j]->bScenecut && scenecutInternal(frames, j -
> 1, j, true) )
> -                {
> -                    m_extendGopBoundary = true;
> -                    break;
> -                }
> +                if (( m_param->scenecutThreshold && frames[j]->bScenecut
> && scenecutInternal(frames, j - 1, j, true)) ||
> +                    (m_param->bHistBasedSceneCut && frames[j]->bScenecut))
> +                    {
> +                        m_extendGopBoundary = true;
> +                        break;
> +                    }
>              }
>              if (m_extendGopBoundary)
>                  break;
> @@ -2097,13 +2126,14 @@
>          {
>              for (int j = 1; j < numBFrames + 1; j++)
>              {
> -                if (scenecut(frames, j, j + 1, false, origNumFrames) ||
> +                if ((m_param->scenecutThreshold && scenecut(frames, j, j
> + 1, false, origNumFrames)) ||
> +                    (m_param->bHistBasedSceneCut && frames[j +
> 1]->bScenecut) ||
>                      (bForceRADL && (frames[j]->frameNum == preRADL)))
> -                {
> -                    frames[j]->sliceType = X265_TYPE_P;
> -                    numAnalyzed = j;
> -                    break;
> -                }
> +                    {
> +                        frames[j]->sliceType = X265_TYPE_P;
> +                        numAnalyzed = j;
> +                        break;
> +                    }
>              }
>          }
>          resetStart = bKeyframe ? 1 : X265_MIN(numBFrames + 2, numAnalyzed
> + 1);
> @@ -3289,3 +3319,5 @@
>      fenc->rowSatds[b - p0][p1 - b][cuY] += bcostAq;
>      fenc->lowresCosts[b - p0][p1 - b][cuXY] = (uint16_t)(X265_MIN(bcost,
> LOWRES_COST_MASK) | (listused << LOWRES_COST_SHIFT));
>  }
> +
> +}
> diff -r 04db2bfee5d6 -r 40beab295ca2 source/encoder/slicetype.h
> --- a/source/encoder/slicetype.h Thu Oct 31 16:23:27 2019 +0530
> +++ b/source/encoder/slicetype.h Wed Nov 13 18:18:31 2019 +0530
> @@ -43,6 +43,13 @@
>  #define AQ_EDGE_BIAS 0.5
>  #define EDGE_INCLINATION 45
>
> +#ifdef HIGH_BIT_DEPTH
> +#define edgeThreshold 1023.0
> +#else
> +#define edgeThreshold 255.0
> +#endif
> +#define PI 3.14159265
> +
>  /* Thread local data for lookahead tasks */
>  struct LookaheadTLD
>  {
> @@ -258,6 +265,7 @@
>      CostEstimateGroup& operator=(const CostEstimateGroup&);
>  };
>
> -}
> +bool computeEdge(pixel *edgePic, pixel *refPic, pixel *edgeTheta,
> intptr_t stride, int height, int width, bool bcalcTheta);
>
> +}
>  #endif // ifndef X265_SLICETYPE_H
> diff -r 04db2bfee5d6 -r 40beab295ca2 source/test/regression-tests.txt
> --- a/source/test/regression-tests.txt Thu Oct 31 16:23:27 2019 +0530
> +++ b/source/test/regression-tests.txt Wed Nov 13 18:18:31 2019 +0530
> @@ -159,6 +159,7 @@
>  Traffic_4096x2048_30p.y4m, --preset medium --frame-dup --dup-threshold 60
> --hrd --bitrate 10000 --vbv-bufsize 15000 --vbv-maxrate 12000
>  Kimono1_1920x1080_24_400.yuv,--preset superfast --qp 28 --zones 0,139,q=32
>  Island_960x540_420p_8bit_24fps.yuv,--no-cutree --aq-mode 0 --bitrate 6000
> --scenecut-aware-qp
> +sintel_trailer_2k_1920x1080_24.yuv, --preset medium --hist-scenecut
> --hist-threshold 0.02 --frame-dup --dup-threshold 60 --hrd --bitrate 10000
> --vbv-bufsize 15000 --vbv-maxrate 12000
>
Please add one more CLI to test the functionality of hist-scenecut in the
absence of frame duplication.

>
>  # Main12 intraCost overflow bug test
>  720p50_parkrun_ter.y4m,--preset medium
> diff -r 04db2bfee5d6 -r 40beab295ca2 source/x265.h
> --- a/source/x265.h Thu Oct 31 16:23:27 2019 +0530
> +++ b/source/x265.h Wed Nov 13 18:18:31 2019 +0530
> @@ -211,7 +211,7 @@
>      uint32_t                          numCUsInFrame;
>      uint32_t                          numPartitions;
>      uint32_t                          depthBytes;
> -    int                               bScenecut;
> +    bool                              bScenecut;
>
This will affect backward compatibility.

>      x265_weight_param*                wt;
>      x265_analysis_inter_data*         interData;
>      x265_analysis_intra_data*         intraData;
> @@ -294,7 +294,7 @@
>      double           avgChromaVLevel;
>
>      char             sliceType;
> -    int              bScenecut;
> +    bool             bScenecut;
>
Affects backward compatibility.

>      double           ipCostRatio;
>      int              frameLatency;
>      x265_cu_stats    cuStats;
> @@ -1024,7 +1024,8 @@
>      int       lookaheadSlices;
>
>      /* An arbitrary threshold which determines how aggressively the
> lookahead
> -     * should detect scene cuts. The default (40) is recommended. */
> +     * should detect scene cuts for cost based scenecut detection.
> +     * The default (40) is recommended. */
>      int       scenecutThreshold;
>
>      /* Replace keyframes by using a column of intra blocks that move
> across the video
> @@ -1846,6 +1847,16 @@
>      /* The offset by which QP is incremented for inter-frames when
> bEnableSceneCutAwareQp is set.
>       * Default is +5. */
>      int       maxQpDelta;
> +
> +    /* A genuine threshold used for histogram based scene cut detection.
> +      * This threshold determines whether a frame is a scenecut or not
> +      * when compared against the edge and chroma histogram sad values.
> +      * Default 0.01. Range: Real number in the interval (0,2). */
> +      double    edgeTransitionThreshold;
> +
> +    /* Enables histogram based scenecut detection algorithm to detect
> scenecuts. */
> +      bool      bHistBasedSceneCut;
> +
>
Indentation issue

>  } x265_param;
>  /* x265_param_alloc:
>   *  Allocates an x265_param instance. The returned param structure is not
> diff -r 04db2bfee5d6 -r 40beab295ca2 source/x265cli.h
> --- a/source/x265cli.h Thu Oct 31 16:23:27 2019 +0530
> +++ b/source/x265cli.h Wed Nov 13 18:18:31 2019 +0530
> @@ -129,6 +129,9 @@
>      { "scenecut",       required_argument, NULL, 0 },
>      { "no-scenecut",          no_argument, NULL, 0 },
>      { "scenecut-bias",  required_argument, NULL, 0 },
> +    { "hist-scenecut",        no_argument, NULL, 0},
> +    { "no-hist-scenecut",     no_argument, NULL, 0},
> +    { "hist-threshold", required_argument, NULL, 0},
>      { "fades",                no_argument, NULL, 0 },
>      { "no-fades",             no_argument, NULL, 0 },
>      { "scenecut-aware-qp",    no_argument, NULL, 0 },
> @@ -489,7 +492,10 @@
>      H0("   --gop-lookahead <integer>     Extends gop boundary if a
> scenecut is found within this from keyint boundary. Default 0\n");
>      H0("   --no-scenecut                 Disable adaptive I-frame
> decision\n");
>      H0("   --scenecut <integer>          How aggressively to insert extra
> I-frames. Default %d\n", param->scenecutThreshold);
> -    H1("   --scenecut-bias <0..100.0>    Bias for scenecut detection.
> Default %.2f\n", param->scenecutBias);
> +    H1("   --scenecut-bias <0..100.0>    Bias for scenecut detection.
> Default %.2f\n", param->scenecutBias);
> +    H0("   --hist-scenecut               Enables histogram based
> scene-cut detection using histogram based algorithm.\n");
> +    H0("   --no-hist-scenecut            Disables histogram based
> scene-cut detection using histogram based algorithm.\n");
> +    H1("   --hist-threshold <0.0..2.0>   Luma Edge histogram's Normalized
> SAD threshold for histogram based scenecut detection Default %.2f\n",
> param->edgeTransitionThreshold);
>      H0("   --[no-]fades                  Enable detection and handling of
> fade-in regions. Default %s\n", OPT(param->bEnableFades));
>      H1("   --[no-]scenecut-aware-qp      Enable increasing QP for frames
> inside the scenecut window after scenecut. Default %s\n",
> OPT(param->bEnableSceneCutAwareQp));
>      H1("   --scenecut-window <0..1000>   QP incremental duration(in
> milliseconds) when scenecut-aware-qp is enabled. Default %d\n",
> param->scenecutWindow);
>
> --
> *With Regards,*
> *Srikanth Kurapati.*
> _______________________________________________
> x265-devel mailing list
> x265-devel at videolan.org
> https://mailman.videolan.org/listinfo/x265-devel
>


-- 
Regards,
*Aruna Matheswaran,*
Video Codec Engineer,
Media & AI analytics BU,
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