cabac.c

本源码是H.26L标准的Visual C++源代码

/*
***********************************************************************
* COPYRIGHT AND WARRANTY INFORMATION
*
* Copyright 2001, International Telecommunications Union, Geneva
*
* DISCLAIMER OF WARRANTY
*
* These software programs are available to the user without any
* license fee or royalty on an "as is" basis. The ITU disclaims
* any and all warranties, whether express, implied, or
* statutory, including any implied warranties of merchantability
* or of fitness for a particular purpose.  In no event shall the
* contributor or the ITU be liable for any incidental, punitive, or
* consequential damages of any kind whatsoever arising from the
* use of these programs.
*
* This disclaimer of warranty extends to the user of these programs
* and user's customers, employees, agents, transferees, successors,
* and assigns.
*
* The ITU does not represent or warrant that the programs furnished
* hereunder are free of infringement of any third-party patents.
* Commercial implementations of ITU-T Recommendations, including
* shareware, may be subject to royalty fees to patent holders.
* Information regarding the ITU-T patent policy is available from
* the ITU Web site at http://www.itu.int.
*
* THIS IS NOT A GRANT OF PATENT RIGHTS - SEE THE ITU-T PATENT POLICY.
************************************************************************
*/

/*!
 *************************************************************************************
 * \file cabac.c
 *
 * \brief
 *    CABAC entropy coding routines
 *
 * \author
 *    Main contributors (see contributors.h for copyright, address and affiliation details)
 *    - Detlev Marpe                    <[e-mail]>
 **************************************************************************************
 */

#include <stdlib.h>
#include <math.h>
#include <memory.h>
#include "cabac.h"

/*!
 ************************************************************************
 * \brief
 *    Allocation of contexts models for the motion info
 *    used for arithmetic encoding
 ************************************************************************
 */
MotionInfoContexts* create_contexts_MotionInfo(void)
{

  int j;
  MotionInfoContexts *enco_ctx;


  enco_ctx = (MotionInfoContexts*) calloc(1, sizeof(MotionInfoContexts) );
  if( enco_ctx == NULL )
    no_mem_exit("create_contexts_MotionInfo: enco_ctx");

  for (j=0; j<2; j++)//separately  for P and B
  {
    enco_ctx->mb_type_contexts[j] = (BiContextTypePtr) malloc(NUM_MB_TYPE_CTX  * sizeof( BiContextType ) );

    if( enco_ctx->mb_type_contexts[j] == NULL )
      no_mem_exit("create_contexts_MotionInfo: enco_ctx->mb_type_contexts");

    enco_ctx->mv_res_contexts[j] = (BiContextTypePtr) malloc(NUM_MV_RES_CTX  * sizeof( BiContextType ) );

    if( enco_ctx->mv_res_contexts[j] == NULL )
      no_mem_exit("create_contexts_MotionInfo: enco_ctx->mv_res_contexts");
  }

  enco_ctx->ref_no_contexts = (BiContextTypePtr) malloc(NUM_REF_NO_CTX * sizeof( BiContextType ) );

  if( enco_ctx->ref_no_contexts == NULL )
    no_mem_exit("create_contexts_MotionInfo: enco_ctx->ref_no_contexts");

  enco_ctx->delta_qp_contexts = (BiContextTypePtr) malloc(NUM_DELTA_QP_CTX * sizeof( BiContextType ) );

  if( enco_ctx->delta_qp_contexts == NULL )
    no_mem_exit("create_contexts_MotionInfo: enco_ctx->delta_qp_contexts");

  return enco_ctx;
}


/*!
 ************************************************************************
 * \brief
 *    Allocates of contexts models for the texture info
 *    used for arithmetic encoding
 ************************************************************************
 */
TextureInfoContexts* create_contexts_TextureInfo(void)
{

  int j,k;
  TextureInfoContexts *enco_ctx;

  enco_ctx = (TextureInfoContexts*) calloc(1, sizeof(TextureInfoContexts) );
  if( enco_ctx == NULL )
    no_mem_exit("create_contexts_TextureInfo: enco_ctx");

  for (j=0; j < 6; j++)// 6 different prediction modes,each for Intra 4x4 and Intra 16x16.
  {

    enco_ctx->ipr_contexts[j] = (BiContextTypePtr) malloc(NUM_IPR_CTX  * sizeof( BiContextType ) );

    if( enco_ctx->ipr_contexts[j] == NULL )
      no_mem_exit("create_contexts_TextureInfo: enco_ctx->ipr_contexts");
  }

  for (k=0; k<2; k++)// two for Intra 4x4 and Intra 16x16,three for 3 bits???
    for (j=0; j<3; j++)
    {

      enco_ctx->cbp_contexts[k][j] = (BiContextTypePtr) malloc(NUM_CBP_CTX  * sizeof( BiContextType ) );

      if( enco_ctx->cbp_contexts[k][j] == NULL )
        no_mem_exit("create_contexts_TextureInfo: enco_ctx->cbp_contexts");
    }


  for (j=0; j < NUM_TRANS_TYPE; j++) // there are 9 different contexts.
  {

    enco_ctx->level_context[j] = (BiContextTypePtr) malloc(NUM_LEVEL_CTX  * sizeof( BiContextType ) );
   
    if( enco_ctx->level_context[j] == NULL )
      no_mem_exit("create_contexts_TextureInfo: enco_ctx->level_context");


    enco_ctx->run_context[j] = (BiContextTypePtr) malloc(NUM_RUN_CTX  * sizeof( BiContextType ) );

    if( enco_ctx->run_context[j] == NULL )
      no_mem_exit("create_contexts_TextureInfo: enco_ctx->run_context");

  }
  return enco_ctx;
}


/*!
 ************************************************************************
 * \brief
 *    Initializes an array of contexts models with some pre-defined
 *    counts (ini_flag = 1) or with a flat histogram (ini_flag = 0)
 ************************************************************************
 */
void init_contexts_MotionInfo(MotionInfoContexts *enco_ctx, int ini_flag)
{

  int i,j;
  int scale_factor;
  int qp_factor;
  int ini[3];

  if ( (img->width*img->height) <=  (IMG_WIDTH * IMG_HEIGHT) ) //  format <= QCIF
    scale_factor=1;
  else
    scale_factor=2;

  if(img->qp <= 10)
    qp_factor=0;
  else
    qp_factor=img->qp-10;

  for (j=0; j<2; j++)
  {
    if (ini_flag)
    {
      for (i=0; i < NUM_MB_TYPE_CTX; i++)
      {
        ini[0] = MB_TYPE_Ini[j][i][0]+(MB_TYPE_Ini[j][i][3]*qp_factor)/10;
        ini[1] = MB_TYPE_Ini[j][i][1]+(MB_TYPE_Ini[j][i][4]*qp_factor)/10;
        ini[2] = MB_TYPE_Ini[j][i][2]*scale_factor;
        biari_init_context(enco_ctx->mb_type_contexts[j] + i,ini[0],ini[1],ini[2]);
      }
    }
    else
    {
      for (i=0; i < NUM_MB_TYPE_CTX; i++)
        biari_init_context(enco_ctx->mb_type_contexts[j] + i,1,1,100);
    }

    if (ini_flag)
    {
      for (i=0; i < NUM_MV_RES_CTX; i++)
        biari_init_context(enco_ctx->mv_res_contexts[j] + i,MV_RES_Ini[j][i][0]*scale_factor,MV_RES_Ini[j][i][1]*scale_factor,MV_RES_Ini[j][i][2]*scale_factor);
    }
    else
    {
      for (i=0; i < NUM_MV_RES_CTX; i++)
        biari_init_context(enco_ctx->mv_res_contexts[j] + i,1,1,1000);
    }
  }

  if (ini_flag)
  {
    for (i=0; i < NUM_REF_NO_CTX; i++)
      biari_init_context(enco_ctx->ref_no_contexts + i,REF_NO_Ini[i][0]*scale_factor,REF_NO_Ini[i][1]*scale_factor,REF_NO_Ini[i][2]*scale_factor);
  }
  else
  {
    for (i=0; i < NUM_REF_NO_CTX; i++)
      biari_init_context(enco_ctx->ref_no_contexts + i,1,1,1000);
  }

  if (ini_flag)
  {
    for (i=0; i < NUM_DELTA_QP_CTX; i++)
      biari_init_context(enco_ctx->delta_qp_contexts + i,DELTA_QP_Ini[i][0]*scale_factor,DELTA_QP_Ini[i][1]*scale_factor,DELTA_QP_Ini[i][2]*scale_factor);
  }
  else
  {
    for (i=0; i < NUM_DELTA_QP_CTX; i++)
      biari_init_context(enco_ctx->delta_qp_contexts + i,1,1,1000);
  }
}

/*!
 ************************************************************************
 * \brief
 *    Initializes an array of contexts models with some pre-defined
 *    counts (ini_flag = 1) or with a flat histogram (ini_flag = 0)
 ************************************************************************
 */
void init_contexts_TextureInfo(TextureInfoContexts *enco_ctx, int ini_flag)
{

  int i,j,k;
  int scale_factor;
  int qp_factor;
  int ini[3];

  if ( (img->width*img->height) <=  (IMG_WIDTH * IMG_HEIGHT) ) //  format <= QCIF
   scale_factor=1;
  else
   scale_factor=2;

  if(img->qp <= 10)
    qp_factor=0;
  else
    qp_factor=img->qp-10;

  for (j=0; j < 6; j++)
  {
    if (ini_flag)
    {
      for (i=0; i < NUM_IPR_CTX; i++)
        biari_init_context(enco_ctx->ipr_contexts[j] + i,IPR_Ini[j][i][0]*scale_factor,IPR_Ini[j][i][1]*scale_factor,IPR_Ini[j][i][2]*scale_factor);
    }
    else
    {
      for (i=0; i < NUM_IPR_CTX; i++)
        biari_init_context(enco_ctx->ipr_contexts[j] + i,2,1,50);
    }
  }

  for (k=0; k<2; k++)
    for (j=0; j<3; j++)
    {
      if (ini_flag)
      {
        for (i=0; i < NUM_CBP_CTX; i++)
        {
          ini[0] = CBP_Ini[k][j][i][0]+(CBP_Ini[k][j][i][3]*qp_factor)/10;
          ini[1] = CBP_Ini[k][j][i][1]+(CBP_Ini[k][j][i][4]*qp_factor)/10;
          ini[2] = CBP_Ini[k][j][i][2]*scale_factor;
          biari_init_context(enco_ctx->cbp_contexts[k][j] + i,ini[0],ini[1],ini[2]);
        }
      }
      else
      {
        for (i=0; i < NUM_CBP_CTX; i++)
          biari_init_context(enco_ctx->cbp_contexts[k][j] + i,1,1,100);
      }
    }

  for (j=0; j < NUM_TRANS_TYPE; j++)
  {

    if (ini_flag)
    {
      for (i=0; i < NUM_LEVEL_CTX; i++)
      {
        ini[0] = (Level_Ini[j][i][0]+(Level_Ini[j][i][3]*qp_factor)/10)*scale_factor;
        ini[1] = (Level_Ini[j][i][1]+(Level_Ini[j][i][4]*qp_factor)/10)*scale_factor;
        ini[2] = Level_Ini[j][i][2]*scale_factor;
        biari_init_context(enco_ctx->level_context[j] + i,ini[0],ini[1],ini[2]);
      }
    }
    else
    {
      for (i=0; i < NUM_LEVEL_CTX; i++)
        biari_init_context(enco_ctx->level_context[j] + i,1,1,100);
    }

    if (ini_flag)
    {
      for (i=0; i < NUM_RUN_CTX; i++)
      {
        ini[0] = Run_Ini[j][i][0]*scale_factor;
        ini[1] = Run_Ini[j][i][1]*scale_factor;
        ini[2] = Run_Ini[j][i][2]*scale_factor;
        biari_init_context(enco_ctx->run_context[j] + i,ini[0],ini[1],ini[2]);
      }
    }
    else
    {
      for (i=0; i < NUM_RUN_CTX; i++)
        biari_init_context(enco_ctx->run_context[j] + i,1,1,100);
    }
  }
}


/*!
 ************************************************************************
 * \brief
 *    Frees the memory of the contexts models
 *    used for arithmetic encoding of the motion info.
 ************************************************************************
 */
void delete_contexts_MotionInfo(MotionInfoContexts *enco_ctx)
{

  int j;

  if( enco_ctx == NULL )
    return;

  for (j=0; j<2; j++)
  {
    if (enco_ctx->mb_type_contexts[j] != NULL)
      free(enco_ctx->mb_type_contexts[j] );

    if (enco_ctx->mv_res_contexts[j]  != NULL)
      free(enco_ctx->mv_res_contexts[j] );
  }

  if (enco_ctx->ref_no_contexts != NULL)
    free(enco_ctx->ref_no_contexts);

  if (enco_ctx->delta_qp_contexts != NULL)
    free(enco_ctx->delta_qp_contexts);


  free( enco_ctx );

  return;

}

/*!
 ************************************************************************
 * \brief
 *    Frees the memory of the contexts models
 *    used for arithmetic encoding of the texture info.
 ************************************************************************
 */
void delete_contexts_TextureInfo(TextureInfoContexts *enco_ctx)
{

  int j,k;

  if( enco_ctx == NULL )
    return;

  for (j=0; j < 6; j++)
  {
    if (enco_ctx->ipr_contexts[j] != NULL)
      free(enco_ctx->ipr_contexts[j]);
  }

  for (k=0; k<2; k++)
    for (j=0; j<3; j++)
    {
      if (enco_ctx->cbp_contexts[k][j] != NULL)
        free(enco_ctx->cbp_contexts[k][j]);
    }