macroblock.c

MPEG-4编解码的实现(包括MPEG4视音频编解码)

/*
***********************************************************************
* 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 macroblock.c
 *
 * \brief
 *    Process one macroblock
 *
 * \author
 *    Main contributors (see contributors.h for copyright, address and affiliation details)
 *    - Inge Lille-Lang鴜               <[e-mail]>
 *    - Rickard Sjoberg                 <[e-mail]>
 *    - Jani Lainema                    <[e-mail]>
 *    - Sebastian Purreiter             <[e-mail]>
 *    - Detlev Marpe                    <[e-mail]>
 *    - Thomas Wedi                     <[e-mail]>
 *    - Ragip Kurceren                  <[e-mail]>
 *************************************************************************************
 */
#include "contributors.h"

#include <math.h>
#include <stdlib.h>

#include "elements.h"
#include "macroblock.h"
#include "refbuf.h"


/*!
 ************************************************************************
 * \brief
 *    updates the coordinates and statistics parameter for the
 *    next macroblock
 ************************************************************************
 */
void proceed2nextMacroblock()
{
#if TRACE
  int use_bitstream_backing = (input->slice_mode == FIXED_RATE || input->slice_mode == CALLBACK);
#endif
  const int number_mb_per_row = img->width / MB_BLOCK_SIZE ;
  Macroblock *currMB = &img->mb_data[img->current_mb_nr];

#if TRACE
  int i;
  if (p_trace)
  {
    if(use_bitstream_backing)
      fprintf(p_trace, "\n*********** Pic: %i (I/P) MB: %i Slice: %i **********\n\n", frame_no, img->current_mb_nr, img->current_slice_nr);
   // Write out the tracestring for each symbol
     for (i=0; i<currMB->currSEnr; i++)
       trace2out(&(img->MB_SyntaxElements[i]));
  }
#endif

  // Update the statistics
  stat->bit_use_mb_type[img->type]      += currMB->bitcounter[BITS_MB_MODE];
  stat->bit_use_coeffY[img->type]       += currMB->bitcounter[BITS_COEFF_Y_MB] ;
  stat->bit_use_mode_inter[img->mb_mode]+= currMB->bitcounter[BITS_INTER_MB];
  stat->tmp_bit_use_cbp[img->type]      += currMB->bitcounter[BITS_CBP_MB];
  stat->bit_use_coeffC[img->type]       += currMB->bitcounter[BITS_COEFF_UV_MB];
  stat->bit_use_delta_quant[img->type]  += currMB->bitcounter[BITS_DELTA_QUANT_MB];

/*  if (input->symbol_mode == UVLC)
    stat->bit_ctr += currMB->bitcounter[BITS_TOTAL_MB]; */
  if (img->type==INTRA_IMG)
    ++stat->mode_use_intra[img->mb_mode];
  else
    if (img->type != B_IMG)
      ++stat->mode_use_inter[img->mb_mode];
    else
      ++stat->mode_use_Bframe[img->mb_mode];

  // Update coordinates of macroblock
  img->mb_x++;
  if (img->mb_x == number_mb_per_row) // next row of MBs
  {
    img->mb_x = 0; // start processing of next row
    img->mb_y++;
  }
  img->current_mb_nr++;


  // Define vertical positions
  img->block_y = img->mb_y * BLOCK_SIZE;      // vertical luma block position
  img->pix_y   = img->mb_y * MB_BLOCK_SIZE;   // vertical luma macroblock position
  img->pix_c_y = img->mb_y * MB_BLOCK_SIZE/2; // vertical chroma macroblock position

  if (img->type != B_IMG)
  {
    if (input->intra_upd > 0 && img->mb_y <= img->mb_y_intra)
      img->height_err=(img->mb_y_intra*16)+15;     // for extra intra MB
    else
      img->height_err=img->height-1;
  }

  // Define horizontal positions
  img->block_x = img->mb_x * BLOCK_SIZE;        // luma block
  img->pix_x   = img->mb_x * MB_BLOCK_SIZE;     // luma pixel
  img->block_c_x = img->mb_x * BLOCK_SIZE/2;    // chroma block
  img->pix_c_x   = img->mb_x * MB_BLOCK_SIZE/2; // chroma pixel

  // Statistics
  if ((img->type == INTER_IMG)||(img->types==SP_IMG) )
  {
    ++stat->quant0;
    stat->quant1 += img->qp;      // to find average quant for inter frames
  }
}

/*!
 ************************************************************************
 * \brief
 *    initializes the current macroblock
 ************************************************************************
 */
void start_macroblock()
{
  int i,j,k,l;
  int x=0, y=0 ;
  int use_bitstream_backing = (input->slice_mode == FIXED_RATE || input->slice_mode == CALLBACK);
  Macroblock *currMB = &img->mb_data[img->current_mb_nr];
  Slice *curr_slice = img->currentSlice;
  DataPartition *dataPart;
  Bitstream *currStream;
  EncodingEnvironmentPtr eep;

  if(use_bitstream_backing)
  {
     // Save image to allow recoding if necessary
     for(y=0; y<img->height; y++)
       for(x=0; x<img->width; x++)
         imgY_tmp[y][x] = imgY[y][x];
     for(i=0; i<2; i++)
       for(y=0; y<img->height_cr; y++)
         for(x=0; x<img->width_cr; x++)
           imgUV_tmp[i][y][x] = imgUV[i][y][x];

    // Keep the current state of the bitstreams
    if(!img->cod_counter)
      for (i=0; i<curr_slice->max_part_nr; i++)
      {
        dataPart = &(curr_slice->partArr[i]);
        currStream = dataPart->bitstream;
        currStream->stored_bits_to_go   = currStream->bits_to_go;
        currStream->stored_byte_pos   = currStream->byte_pos;
        currStream->stored_byte_buf   = currStream->byte_buf;

        if (input->symbol_mode ==CABAC)
        {
          eep = &(dataPart->ee_cabac);
          eep->ElowS            = eep->Elow;
          eep->EhighS           = eep->Ehigh;
          eep->EbufferS         = eep->Ebuffer;
          eep->Ebits_to_goS     = eep->Ebits_to_go;
          eep->Ebits_to_followS = eep->Ebits_to_follow;
          eep->EcodestrmS       = eep->Ecodestrm;
          eep->Ecodestrm_lenS   = eep->Ecodestrm_len;
        }
      }
  }

  // Save the slice number of this macroblock. When the macroblock below
  // is coded it will use this to decide if prediction for above is possible
  img->slice_numbers[img->current_mb_nr] = img->current_slice_nr;

  // Save the slice and macroblock number of the current MB
  currMB->slice_nr = img->current_slice_nr;

    // Initialize delta qp change from last macroblock. Feature may be used for future rate control
  currMB->delta_qp=0;

  // Initialize counter for MB symbols
  currMB->currSEnr=0;

  // If MB is next to a slice boundary, mark neighboring blocks unavailable for prediction
  CheckAvailabilityOfNeighbors(img);

  // Reset vectors before doing motion search in motion_search().
  if (img->type != B_IMG)
  {
    for (k=0; k < 2; k++)
    {
      for (j=0; j < BLOCK_MULTIPLE; j++)
        for (i=0; i < BLOCK_MULTIPLE; i++)
          tmp_mv[k][img->block_y+j][img->block_x+i+4]=0;
    }
  }

  // Reset syntax element entries in MB struct
  currMB->ref_frame = 0;
  currMB->mb_type   = 0;
  currMB->cbp_blk   = 0;
  currMB->cbp       = 0;

  for (l=0; l < 2; l++)
    for (j=0; j < BLOCK_MULTIPLE; j++)
      for (i=0; i < BLOCK_MULTIPLE; i++)
        for (k=0; k < 2; k++)
          currMB->mvd[l][j][i][k] = 0;

  for (i=0; i < (BLOCK_MULTIPLE*BLOCK_MULTIPLE); i++)
    currMB->intra_pred_modes[i] = 0;


  // Initialize bitcounters for this macroblock
  if(img->current_mb_nr == 0) // No slice header to account for
  {
    currMB->bitcounter[BITS_HEADER] = 0;
  }
  else if (img->slice_numbers[img->current_mb_nr] == img->slice_numbers[img->current_mb_nr-1]) // current MB belongs to the
  // same slice as the last MB
  {
    currMB->bitcounter[BITS_HEADER] = 0;
  }

  currMB->bitcounter[BITS_MB_MODE] = 0;
  currMB->bitcounter[BITS_COEFF_Y_MB] = 0;
  currMB->bitcounter[BITS_INTER_MB] = 0;
  currMB->bitcounter[BITS_CBP_MB] = 0;
  currMB->bitcounter[BITS_DELTA_QUANT_MB] = 0;
  currMB->bitcounter[BITS_COEFF_UV_MB] = 0;

#ifdef _FAST_FULL_ME_
  ResetFastFullIntegerSearch ();
#endif
}

/*!
 ************************************************************************
 * \brief
 *    terminates processing of the current macroblock depending
 *    on the chosen slice mode
 ************************************************************************
 */
void terminate_macroblock(Boolean *end_of_slice, Boolean *recode_macroblock)
{
  int i,x=0, y=0 ;
  Slice *currSlice = img->currentSlice;
  Macroblock    *currMB    = &img->mb_data[img->current_mb_nr];
  SyntaxElement *currSE    = &img->MB_SyntaxElements[currMB->currSEnr];
  int *partMap = assignSE2partition[input->partition_mode];
  DataPartition *dataPart;
  Bitstream *currStream;
  int rlc_bits=0;
  EncodingEnvironmentPtr eep;
  int use_bitstream_backing = (input->slice_mode == FIXED_RATE || input->slice_mode == CALLBACK);
  int new_slice = ( (img->current_mb_nr == 0) || img->mb_data[img->current_mb_nr-1].slice_nr != img->current_slice_nr);
  static int skip = FALSE;

  switch(input->slice_mode)
  {
  case NO_SLICES:
    *recode_macroblock = FALSE;
    if ((img->current_mb_nr+1) == img->total_number_mb) // maximum number of MBs
      *end_of_slice = TRUE;
    break;
  case FIXED_MB:
    // For slice mode one, check if a new slice boundary follows
    *recode_macroblock = FALSE;
    if ( ((img->current_mb_nr+1) % input->slice_argument == 0) || ((img->current_mb_nr+1) == img->total_number_mb) )
    {
      *end_of_slice = TRUE;
    }
    break;

    // For slice modes two and three, check if coding of this macroblock
    // resulted in too many bits for this slice. If so, indicate slice
    // boundary before this macroblock and code the macroblock again
  case FIXED_RATE:
     // in case of skip MBs check if there is a slice boundary
     // only for UVLC (img->cod_counter is always 0 in case of CABAC)
     if(img->cod_counter)
     {
       // write out the skip MBs to know how many bits we need for the RLC
       dataPart = &(currSlice->partArr[partMap[SE_MBTYPE]]);
       currSE->value1 = img->cod_counter;
       currSE->mapping = n_linfo2;
       currSE->type = SE_MBTYPE;
       dataPart->writeSyntaxElement(  currSE, dataPart);
       rlc_bits=currSE->len;

       currStream = dataPart->bitstream;
       // save the bitstream as it would be if we write the skip MBs
       currStream->bits_to_go_skip  = currStream->bits_to_go;
       currStream->byte_pos_skip    = currStream->byte_pos;
       currStream->byte_buf_skip    = currStream->byte_buf;
       // restore the bitstream
       currStream->bits_to_go = currStream->stored_bits_to_go;
       currStream->byte_pos = currStream->stored_byte_pos;
       currStream->byte_buf = currStream->stored_byte_buf;
       skip = TRUE;
     }
     //! Check if the last coded macroblock fits into the size of the slice
     //! But only if this is not the first macroblock of this slice
     if (!new_slice)
     {
       if(slice_too_big(rlc_bits))
       {
         *recode_macroblock = TRUE;
         *end_of_slice = TRUE;
       }
       else if(!img->cod_counter)
         skip = FALSE;
     }
     // maximum number of MBs
     if ((*recode_macroblock == FALSE) && ((img->current_mb_nr+1) == img->total_number_mb)) 
     {
       *end_of_slice = TRUE;
       if(!img->cod_counter)
         skip = FALSE;
     }
   
     //! (first MB OR first MB in a slice) AND bigger that maximum size of slice
     if (new_slice && slice_too_big(rlc_bits))
     {
       *end_of_slice = TRUE;
       if(!img->cod_counter)
         skip = FALSE;
     }
     break;

  case  CALLBACK:
    if (img->current_mb_nr > 0 && !new_slice)
    {
      if (currSlice->slice_too_big(rlc_bits))
      {
        *recode_macroblock = TRUE;
        *end_of_slice = TRUE;
      }
    }
    if ( (*recode_macroblock == FALSE) && ((img->current_mb_nr+1) == img->total_number_mb) ) // maximum number of MBs
      *end_of_slice = TRUE;
    break;
  default:
    snprintf(errortext, ET_SIZE, "Slice Mode %d not supported", input->slice_mode);
    error(errortext, 600);
  }

  if(*recode_macroblock == TRUE)
  {
    // Restore everything
    for (i=0; i<currSlice->max_part_nr; i++)
    {
      dataPart = &(currSlice->partArr[i]);
      currStream = dataPart->bitstream;
      currStream->bits_to_go = currStream->stored_bits_to_go;
      currStream->byte_pos  = currStream->stored_byte_pos;
      currStream->byte_buf  = currStream->stored_byte_buf;
      if (input->symbol_mode == CABAC)
      {
        eep = &(dataPart->ee_cabac);
        eep->Elow            = eep->ElowS;
        eep->Ehigh           = eep->EhighS;
        eep->Ebuffer         = eep->EbufferS;
        eep->Ebits_to_go     = eep->Ebits_to_goS;
        eep->Ebits_to_follow = eep->Ebits_to_followS;
        eep->Ecodestrm       = eep->EcodestrmS;
        eep->Ecodestrm_len   = eep->Ecodestrm_lenS;