rdoq_cavlc.c

H.264编码实现

/*!
*************************************************************************************
* \file rdoq_cavlc.c
*
* \brief
*    Rate Distortion Optimized Quantization based on VCEG-AH21 related to CAVLC
*************************************************************************************
*/

#include "contributors.h"

#include <math.h>
#include <float.h>

#include "global.h"
#include "image.h"
#include "fmo.h"
#include "macroblock.h"
#include "mb_access.h"
#include "ratectl.h"
#include "rdoq.h"

extern const int estErr4x4[6][4][4];
extern const int estErr8x8[6][8][8];

extern const byte SNGL_SCAN[16][2]; // need to revisit
extern const byte FIELD_SCAN[16][2]; 

/*!
************************************************************************
* \brief
*    estimate VLC for Coeff Level
************************************************************************
*/
int estSyntaxElement_Level_VLC1(SyntaxElement *se)
{
  int level  = se->value1;
  int sign   = (level < 0 ? 1 : 0);
  int levabs = iabs(level);

  if (levabs < 8)
  {
    se->len = levabs * 2 + sign - 1;
  }
  else if (levabs < 16)
  {
    // escape code1
    se->len = 19;
  }
  else
  {
    // escape code2
    se->len = 28;
  }

  return (se->len);
}



/*!
************************************************************************
* \brief
*    estimate VLC for Coeff Level
************************************************************************
*/
int estSyntaxElement_Level_VLCN(SyntaxElement *se, int vlc)//, DataPartition *this_dataPart)
{
  int level = se->value1;
  int levabs = iabs(level) - 1;  

  int shift = vlc - 1;
  int escape = (15 << shift);

  if (levabs < escape)
  {
    se->len = ((levabs) >> shift) + 1 + vlc;
  }
  else
  {
    se->len = 28;
  }

  return (se->len);
}

int cmp(const void *arg1, const void *arg2)
{
  return (((levelDataStruct *)arg2)->levelDouble - ((levelDataStruct *)arg1)->levelDouble);
}

/*!
************************************************************************
* \brief
*    estimate CAVLC bits
************************************************************************
*/
int est_CAVLC_bits (levelDataStruct *levelData, int level_to_enc[16], int sign_to_enc[16], int nnz, int block_type)
{
  int           no_bits    = 0;
  SyntaxElement se;

  int coeff_ctr, scan_pos = 0;
  int k, level = 1, run = -1, vlcnum;
  int numcoeff = 0, lastcoeff = 0, numtrailingones = 0; 
  int numones = 0, totzeros = 0, zerosleft, numcoef;
  int numcoeff_vlc;
  int level_two_or_higher;
  int max_coeff_num = 0, cdc = (block_type == CHROMA_DC ? 1 : 0);
  int yuv = img->yuv_format - 1;
  static const int incVlc[] = {0, 3, 6, 12, 24, 48, 32768};  // maximum vlc = 6

  int  pLevel[16] = {0};
  int  pRun[16] = {0};

  static const int Token_lentab[3][4][17] = 
  {
    {
      { 1, 6, 8, 9,10,11,13,13,13,14,14,15,15,16,16,16,16},
      { 0, 2, 6, 8, 9,10,11,13,13,14,14,15,15,15,16,16,16},
      { 0, 0, 3, 7, 8, 9,10,11,13,13,14,14,15,15,16,16,16},
      { 0, 0, 0, 5, 6, 7, 8, 9,10,11,13,14,14,15,15,16,16}
    },
    {                                                  
      { 2, 6, 6, 7, 8, 8, 9,11,11,12,12,12,13,13,13,14,14},
      { 0, 2, 5, 6, 6, 7, 8, 9,11,11,12,12,13,13,14,14,14},
      { 0, 0, 3, 6, 6, 7, 8, 9,11,11,12,12,13,13,13,14,14},
      { 0, 0, 0, 4, 4, 5, 6, 6, 7, 9,11,11,12,13,13,13,14}
    },
    {                                                  
      { 4, 6, 6, 6, 7, 7, 7, 7, 8, 8, 9, 9, 9,10,10,10,10},
      { 0, 4, 5, 5, 5, 5, 6, 6, 7, 8, 8, 9, 9, 9,10,10,10},
      { 0, 0, 4, 5, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,10,10,10},
      { 0, 0, 0, 4, 4, 4, 4, 4, 5, 6, 7, 8, 8, 9,10,10,10}
    }
  };

  static const int Totalzeros_lentab[TOTRUN_NUM][16] = 
  {
    { 1,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9},  
    { 3,3,3,3,3,4,4,4,4,5,5,6,6,6,6},  
    { 4,3,3,3,4,4,3,3,4,5,5,6,5,6},  
    { 5,3,4,4,3,3,3,4,3,4,5,5,5},  
    { 4,4,4,3,3,3,3,3,4,5,4,5},  
    { 6,5,3,3,3,3,3,3,4,3,6},  
    { 6,5,3,3,3,2,3,4,3,6},  
    { 6,4,5,3,2,2,3,3,6},  
    { 6,6,4,2,2,3,2,5},  
    { 5,5,3,2,2,2,4},  
    { 4,4,3,3,1,3},  
    { 4,4,2,1,3},  
    { 3,3,1,2},  
    { 2,2,1},  
    { 1,1},  
  };
  static const int Run_lentab[TOTRUN_NUM][16] = 
  {
    {1,1},
    {1,2,2},
    {2,2,2,2},
    {2,2,2,3,3},
    {2,2,3,3,3,3},
    {2,3,3,3,3,3,3},
    {3,3,3,3,3,3,3,4,5,6,7,8,9,10,11},
  };
  static const int Token_lentab_cdc[3][4][17] =
  {
    //YUV420
   {{ 2, 6, 6, 6, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
    { 0, 1, 6, 7, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
    { 0, 0, 3, 7, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
    { 0, 0, 0, 6, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
    //YUV422
   {{ 1, 7, 7, 9, 9,10,11,12,13, 0, 0, 0, 0, 0, 0, 0, 0},
    { 0, 2, 7, 7, 9,10,11,12,12, 0, 0, 0, 0, 0, 0, 0, 0},
    { 0, 0, 3, 7, 7, 9,10,11,12, 0, 0, 0, 0, 0, 0, 0, 0},
    { 0, 0, 0, 5, 6, 7, 7,10,11, 0, 0, 0, 0, 0, 0, 0, 0}},
    //YUV444
   {{ 1, 6, 8, 9,10,11,13,13,13,14,14,15,15,16,16,16,16},
    { 0, 2, 6, 8, 9,10,11,13,13,14,14,15,15,15,16,16,16},
    { 0, 0, 3, 7, 8, 9,10,11,13,13,14,14,15,15,16,16,16},
    { 0, 0, 0, 5, 6, 7, 8, 9,10,11,13,14,14,15,15,16,16}}
  };
  static const int Totalzeros_lentab_cdc[3][TOTRUN_NUM][16] =
  {
    //YUV420
   {{ 1,2,3,3},
    { 1,2,2},
    { 1,1}},
    //YUV422
   {{ 1,3,3,4,4,4,5,5},
    { 3,2,3,3,3,3,3},
    { 3,3,2,2,3,3},
    { 3,2,2,2,3},
    { 2,2,2,2},
    { 2,2,1},
    { 1,1}},
    //YUV444
   {{ 1,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9},
    { 3,3,3,3,3,4,4,4,4,5,5,6,6,6,6},
    { 4,3,3,3,4,4,3,3,4,5,5,6,5,6},
    { 5,3,4,4,3,3,3,4,3,4,5,5,5},
    { 4,4,4,3,3,3,3,3,4,5,4,5},
    { 6,5,3,3,3,3,3,3,4,3,6},
    { 6,5,3,3,3,2,3,4,3,6},
    { 6,4,5,3,2,2,3,3,6},
    { 6,6,4,2,2,3,2,5},
    { 5,5,3,2,2,2,4},
    { 4,4,3,3,1,3},
    { 4,4,2,1,3},
    { 3,3,1,2},
    { 2,2,1},
    { 1,1}}
  };


  max_coeff_num = ( (block_type == CHROMA_DC) ? img->num_cdc_coeff : 
  ( (block_type == LUMA_INTRA16x16AC || block_type == CB_INTRA16x16AC || block_type == CR_INTRA16x16AC || block_type == CHROMA_AC) ? 15 : 16) );

  //convert zigzag scan to (run, level) pairs
  for (coeff_ctr = 0; coeff_ctr < max_coeff_num; coeff_ctr++)
  {
    run++;
    level = level_to_enc[coeff_ctr];
    if (level != 0)
    {
      pLevel[scan_pos] = isignab(level, sign_to_enc[coeff_ctr]);
      pRun  [scan_pos] = run;
      ++scan_pos;
      run = -1;                     // reset zero level counter
    }
  }

  level = 1;
  for(k = 0; (k < max_coeff_num) && level != 0; k++)    
  {
    level = pLevel[k]; // level
    run   = pRun[k];   // run

    if (level)
    {
      totzeros += run; // lets add run always (even if zero) to avoid conditional
      if (iabs(level) == 1)
      {
        numones ++;
        numtrailingones ++;
        numtrailingones = imin(numtrailingones, 3); // clip to 3
      }
      else
      {
        numtrailingones = 0;
      }
      numcoeff ++;
      lastcoeff = k;
    }
  }

  if (!cdc)
  {
    if (nnz < 2)
    {
      numcoeff_vlc = 0;
    }
    else if (nnz < 4)
    {
      numcoeff_vlc = 1;
    }
    else if (nnz < 8)
    {
      numcoeff_vlc = 2;
    }
    else 
    {
      numcoeff_vlc = 3;
    }
  }
  else
  {
    // chroma DC (has its own VLC)
    // numcoeff_vlc not relevant
    numcoeff_vlc = 0;
  }

  se.value1 = numcoeff;
  se.value2 = numtrailingones;
  se.len    = numcoeff_vlc; /* use len to pass vlcnum */

  if (!cdc)
  {
    if (se.len == 3)
      no_bits += 6;  // 4 + 2 bit FLC
    else
      no_bits += Token_lentab[se.len][se.value2][se.value1];
  }
  else
    no_bits += Token_lentab_cdc[yuv][se.value2][se.value1];  

  if (!numcoeff)
    return no_bits;
  else
  {
    if (numtrailingones)
      no_bits += numtrailingones;

    // encode levels
    level_two_or_higher = (numcoeff > 3 && numtrailingones == 3) ? 0 : 1;

    vlcnum = (numcoeff > 10 && numtrailingones < 3) ? 1 : 0;

    for (k = lastcoeff - numtrailingones; k >= 0; k--)
    {
      level = pLevel[k]; // level

      se.value1 = level;

      if (level_two_or_higher)
      {
        level_two_or_higher = 0;
        if (se.value1 > 0)
          se.value1 --;
        else
          se.value1 ++;
      }

      //    encode level
      if (vlcnum == 0)
        estSyntaxElement_Level_VLC1(&se);
      else
        estSyntaxElement_Level_VLCN(&se, vlcnum);

      // update VLC table
      if (iabs(level) > incVlc[vlcnum])
        vlcnum++;

      if ((k == lastcoeff - numtrailingones) && iabs(level) > 3)
        vlcnum = 2;

      no_bits  += se.len;
    }

    // encode total zeroes
    if (numcoeff < max_coeff_num)
    {
      se.value1 = totzeros;

      vlcnum = numcoeff-1;

      se.len = vlcnum;

      if (!cdc)
        no_bits += Totalzeros_lentab[se.len][se.value1];
      else
        no_bits += Totalzeros_lentab_cdc[yuv][se.len][se.value1];
    }

    // encode run before each coefficient
    zerosleft = totzeros;
    numcoef = numcoeff;
    for (k = lastcoeff; k >= 0; k--)
    {
      run = pRun[k]; // run

      se.value1 = run;

      // for last coeff, run is remaining totzeros
      // when zerosleft is zero, remaining coeffs have 0 run
      if ((!zerosleft) || (numcoeff <= 1 ))
        break;