/src/libde265/libde265/intrapred.cc

Source
/*
 * H.265 video codec.
 * Copyright (c) 2013-2014 struktur AG, Dirk Farin <farin@struktur.de>
 *
 * This file is part of libde265.
 *
 * libde265 is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * libde265 is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with libde265.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "intrapred.h"
#include "transform.h"
#include "util.h"
#include "decctx.h"
#include <assert.h>


#include <sys/types.h>
#include <string.h>



void fillIntraPredModeCandidates(enum IntraPredMode candModeList[3],
                                 enum IntraPredMode candIntraPredModeA,
                                 enum IntraPredMode candIntraPredModeB)
{
  // build candidate list

  if (candIntraPredModeA == candIntraPredModeB) {
    if (candIntraPredModeA < 2) {
      candModeList[0] = INTRA_PLANAR;
      candModeList[1] = INTRA_DC;
      candModeList[2] = INTRA_ANGULAR_26;
    }
    else {
      candModeList[0] = candIntraPredModeA;
      candModeList[1] = (enum IntraPredMode)(2 + ((candIntraPredModeA-2 -1 +32) % 32));
      candModeList[2] = (enum IntraPredMode)(2 + ((candIntraPredModeA-2 +1    ) % 32));
    }
  }
  else {
    candModeList[0] = candIntraPredModeA;
    candModeList[1] = candIntraPredModeB;

    if (candIntraPredModeA != INTRA_PLANAR &&
        candIntraPredModeB != INTRA_PLANAR) {
      candModeList[2] = INTRA_PLANAR;
    }
    else if (candIntraPredModeA != INTRA_DC &&
             candIntraPredModeB != INTRA_DC) {
      candModeList[2] = INTRA_DC;
    }
    else {
      candModeList[2] = INTRA_ANGULAR_26;
    }
  }

  /*
    printf("candModeList: %d %d %d\n",
    candModeList[0],
    candModeList[1],
    candModeList[2]
    );
  */
}


void fillIntraPredModeCandidates(enum IntraPredMode candModeList[3], int x,int y, int PUidx,
                                 bool availableA, // left
                                 bool availableB, // top
                                 const de265_image* img)
{
  const seq_parameter_set* sps = &img->get_sps();

  // block on left side

  enum IntraPredMode candIntraPredModeA, candIntraPredModeB;
  if (availableA==false) {
    candIntraPredModeA=INTRA_DC;
  }
  else if (img->get_pred_mode(x-1,y) != MODE_INTRA ||
           img->get_pcm_flag (x-1,y)) {
    candIntraPredModeA=INTRA_DC;
 }
  else {
    candIntraPredModeA = img->get_IntraPredMode_atIndex(PUidx-1);
  }

  // block above

  if (availableB==false) {
    candIntraPredModeB=INTRA_DC;
  }
  else if (img->get_pred_mode(x,y-1) != MODE_INTRA ||
           img->get_pcm_flag (x,y-1)) {
    candIntraPredModeB=INTRA_DC;
  }
  else if (y-1 < ((y >> sps->Log2CtbSizeY) << sps->Log2CtbSizeY)) {
    candIntraPredModeB=INTRA_DC;
  }
  else {
    candIntraPredModeB = img->get_IntraPredMode_atIndex(PUidx-sps->PicWidthInMinPUs);
  }


  logtrace(LogSlice,"%d;%d candA:%d / candB:%d\n", x,y,
           availableA ? candIntraPredModeA : -999,
           availableB ? candIntraPredModeB : -999);


  fillIntraPredModeCandidates(candModeList,
                              candIntraPredModeA,
                              candIntraPredModeB);
}


int find_intra_pred_mode(enum IntraPredMode mode,
                         enum IntraPredMode candModeList[3])
{
  // check whether the mode is in the candidate list

  for (int i=0;i<3;i++) {
    if (candModeList[i] == mode) {
      return i;
    }
  }

  // sort candModeList

  if (candModeList[0] > candModeList[1]) {
    std::swap(candModeList[0],candModeList[1]);
  }
  if (candModeList[0] > candModeList[2]) {
    std::swap(candModeList[0],candModeList[2]);
  }
  if (candModeList[1] > candModeList[2]) {
    std::swap(candModeList[1],candModeList[2]);
  }

  // skip modes already in the candidate list

  int intraMode = mode;

  for (int i=2;i>=0;i--) {
    if (intraMode >= candModeList[i]) { intraMode--; }
  }

  return -intraMode-1;
}


#if 0
void list_chroma_pred_candidates(enum IntraPredMode chroma_mode[5],
                                 enum IntraPredMode luma_mode)
{
  enum IntraPredMode chroma_cand[5];
  chroma_cand[0] = INTRA_PLANAR;
  chroma_cand[1] = INTRA_ANGULAR_26;
  chroma_cand[2] = INTRA_ANGULAR_10;
  chroma_cand[3] = INTRA_DC;
  chroma_cand[4] = luma_mode;

  switch (luma_mode) {
  case INTRA_PLANAR:     chroma_cand[0] = INTRA_ANGULAR_34; break;
  case INTRA_ANGULAR_26: chroma_cand[1] = INTRA_ANGULAR_34; break;
  case INTRA_ANGULAR_10: chroma_cand[2] = INTRA_ANGULAR_34; break;
  case INTRA_DC:         chroma_cand[3] = INTRA_ANGULAR_34; break;
  default:
    // use defaults from above
    break;
  }
}
#endif


int get_intra_scan_idx(int log2TrafoSize, enum IntraPredMode intraPredMode, int cIdx,
                       const seq_parameter_set* sps)
{
  if (log2TrafoSize==2 ||
      (log2TrafoSize==3 && (cIdx==0 ||
                            sps->ChromaArrayType==CHROMA_444))) {
    /**/ if (intraPredMode >=  6 && intraPredMode <= 14) return 2;
    else if (intraPredMode >= 22 && intraPredMode <= 30) return 1;
    else return 0;
  }
  else { return 0; }
}


int get_intra_scan_idx_luma(int log2TrafoSize, enum IntraPredMode intraPredMode)
{
  if (log2TrafoSize==2 || log2TrafoSize==3) {
    /**/ if (intraPredMode >=  6 && intraPredMode <= 14) return 2;
    else if (intraPredMode >= 22 && intraPredMode <= 30) return 1;
    else return 0;
  }
  else { return 0; }
}

int get_intra_scan_idx_chroma(int log2TrafoSize, enum IntraPredMode intraPredMode)
{
  if (log2TrafoSize==1 || log2TrafoSize==2) {
    /**/ if (intraPredMode >=  6 && intraPredMode <= 14) return 2;
    else if (intraPredMode >= 22 && intraPredMode <= 30) return 1;
    else return 0;
  }
  else { return 0; }
}


enum IntraPredMode lumaPredMode_to_chromaPredMode(enum IntraPredMode luma,
                                                  enum IntraChromaPredMode chroma)
{
  switch (chroma) {
  case INTRA_CHROMA_LIKE_LUMA:
    return luma;

  case INTRA_CHROMA_PLANAR_OR_34:
    if (luma==INTRA_PLANAR) return INTRA_ANGULAR_34;
    else                    return INTRA_PLANAR;

  case INTRA_CHROMA_ANGULAR_26_OR_34:
    if (luma==INTRA_ANGULAR_26) return INTRA_ANGULAR_34;
    else                        return INTRA_ANGULAR_26;

  case INTRA_CHROMA_ANGULAR_10_OR_34:
    if (luma==INTRA_ANGULAR_10) return INTRA_ANGULAR_34;
    else                        return INTRA_ANGULAR_10;

  case INTRA_CHROMA_DC_OR_34:
    if (luma==INTRA_DC)         return INTRA_ANGULAR_34;
    else                        return INTRA_DC;
  }


  assert(false);
  return INTRA_DC;
}




// (8.4.4.2.2)
template <class pixel_t>
void fill_border_samples(de265_image* img,
                         int xB,int yB,  // in component specific resolution
                         int nT, int cIdx,
                         pixel_t* out_border)
{
  intra_border_computer<pixel_t> c;
  c.init(out_border, img, nT, cIdx, xB, yB);
  c.preproc();
  c.fill_from_image();
  c.reference_sample_substitution();
}


const int intraPredAngle_table[1+34] =
  { 0, 0,32,26,21,17,13, 9, 5, 2, 0,-2,-5,-9,-13,-17,-21,-26,
    -32,-26,-21,-17,-13,-9,-5,-2,0,2,5,9,13,17,21,26,32 };

const int invAngle_table[25-10] =
  { -4096,-1638,-910,-630,-482,-390,-315,-256,
    -315,-390,-482,-630,-910,-1638,-4096 };


template <class pixel_t>
void decode_intra_prediction_internal(de265_image* img,
                                      int xB0,int yB0,
                                      enum IntraPredMode intraPredMode,
                                      pixel_t* dst, int dstStride,
                                      int nT, int cIdx)
{
  pixel_t  border_pixels_mem[4*MAX_INTRA_PRED_BLOCK_SIZE+1];
  pixel_t* border_pixels = &border_pixels_mem[2*MAX_INTRA_PRED_BLOCK_SIZE];

  fill_border_samples(img, xB0,yB0, nT, cIdx, border_pixels);

  if (img->get_sps().range_extension.intra_smoothing_disabled_flag == 0 &&
      (cIdx==0 || img->get_sps().ChromaArrayType==CHROMA_444))
    {
      intra_prediction_sample_filtering(img->get_sps(), border_pixels, nT, cIdx, intraPredMode);
    }


  const acceleration_functions& acceleration = img->decctx->acceleration;

  switch (intraPredMode) {
  case INTRA_PLANAR:
    acceleration.intra_pred_planar<pixel_t>(dst,dstStride, nT,cIdx, border_pixels);
    break;
  case INTRA_DC:
    acceleration.intra_pred_dc<pixel_t>(dst,dstStride, nT,cIdx, border_pixels);
    break;
  default:
    {
      int bit_depth = img->get_bit_depth(cIdx);
      bool disableIntraBoundaryFilter =
        (img->get_sps().range_extension.implicit_rdpcm_enabled_flag &&
         img->get_cu_transquant_bypass(xB0,yB0));

      acceleration.intra_pred_angular<pixel_t>(dst,dstStride, bit_depth,disableIntraBoundaryFilter,
                                               xB0,yB0,intraPredMode,nT,cIdx, border_pixels);
    }
    break;
  }
}


// (8.4.4.2.1)
void decode_intra_prediction(de265_image* img,
                             int xB0,int yB0,
                             enum IntraPredMode intraPredMode,
                             int nT, int cIdx)
{
  logtrace(LogIntraPred,"decode_intra_prediction xy0:%d/%d mode=%d nT=%d, cIdx=%d\n",
           xB0,yB0, intraPredMode, nT,cIdx);
  /*
    printf("decode_intra_prediction xy0:%d/%d mode=%d nT=%d, cIdx=%d\n",
    xB0,yB0, intraPredMode, nT,cIdx);
  */

  if (img->high_bit_depth(cIdx)) {
    decode_intra_prediction_internal<uint16_t>(img,xB0,yB0, intraPredMode,
                                               img->get_image_plane_at_pos_NEW<uint16_t>(cIdx,xB0,yB0),
                                               img->get_image_stride(cIdx),
                                               nT,cIdx);
  }
  else {
    decode_intra_prediction_internal<uint8_t>(img,xB0,yB0, intraPredMode,
                                              img->get_image_plane_at_pos_NEW<uint8_t>(cIdx,xB0,yB0),
                                              img->get_image_stride(cIdx),
                                              nT,cIdx);
  }
}


// TODO: remove this
template <> void decode_intra_prediction<uint8_t>(de265_image* img,
                                                  int xB0,int yB0,
                                                  enum IntraPredMode intraPredMode,
                                                  uint8_t* dst, int nT, int cIdx)
{
    decode_intra_prediction_internal<uint8_t>(img,xB0,yB0, intraPredMode,
                                              dst,nT,
                                              nT,cIdx);
}


// TODO: remove this
template <> void decode_intra_prediction<uint16_t>(de265_image* img,
                                                   int xB0,int yB0,
                                                   enum IntraPredMode intraPredMode,
                                                   uint16_t* dst, int nT, int cIdx)
{
  decode_intra_prediction_internal<uint16_t>(img,xB0,yB0, intraPredMode,
                                             dst,nT,
                                             nT,cIdx);
}

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Created: 2026-09-14 07:37