macroblock.c

H.264视频编码器(ITU的264编码参考软件)

/*!
 ***********************************************************************
 * \file macroblock.c
 *
 * \brief
 *     Decode a 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]>
 *    - Thomas Wedi                     <[e-mail]>
 *    - Detlev Marpe                    <[e-mail]>
 *    - Gabi Blaettermann               <[e-mail]>
 *    - Ye-Kui Wang                     <[e-mail]>
 *    - Lowell Winger                   <[e-mail]>
 ***********************************************************************
*/

#include "contributors.h"

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

#include "global.h"
#include "mbuffer.h"
#include "elements.h"
#include "errorconcealment.h"
#include "macroblock.h"
#include "fmo.h"
#include "cabac.h"
#include "vlc.h"
#include "image.h"
#include "mb_access.h"
#include "biaridecod.h"

#include "transform8x8.h"

#if TRACE
#define TRACE_STRING(s) strncpy(currSE.tracestring, s, TRACESTRING_SIZE)
#else
#define TRACE_STRING(s) // do nothing
#endif

extern int last_dquant;
extern ColocatedParams *Co_located;


static void SetMotionVectorPredictor (struct img_par  *img,
                                      int             *pmv_x,
                                      int             *pmv_y,
                                      int             ref_frame,
                                      int             list,
                                      int             ***refPic,
                                      int             ****tmp_mv,
                                      int             block_x,
                                      int             block_y,
                                      int             blockshape_x,
                                      int             blockshape_y);


/*!
 ************************************************************************
 * \brief
 *    initializes the current macroblock
 ************************************************************************
 */
void start_macroblock(struct img_par *img,struct inp_par *inp, int CurrentMBInScanOrder)
{
  int i,j,k,l;
  Macroblock *currMB;   // intialization code deleted, see below, StW

  assert (img->current_mb_nr >=0 && img->current_mb_nr < img->PicSizeInMbs);

  currMB = &img->mb_data[img->current_mb_nr];

  /* Update coordinates of the current macroblock */
  if (img->MbaffFrameFlag)
  {
    img->mb_x = (img->current_mb_nr)%((2*img->width)/MB_BLOCK_SIZE);
    img->mb_y = 2*((img->current_mb_nr)/((2*img->width)/MB_BLOCK_SIZE));

    if (img->mb_x % 2)
    {
      img->mb_y++;
    }

    img->mb_x /= 2;
  }
  else
  {
    img->mb_x = (img->current_mb_nr)%(img->width/MB_BLOCK_SIZE);
    img->mb_y = (img->current_mb_nr)/(img->width/MB_BLOCK_SIZE);
  }
  
  /* Define vertical positions */
  img->block_y = img->mb_y * BLOCK_SIZE;      /* luma block position */
  img->pix_y   = img->mb_y * MB_BLOCK_SIZE;   /* luma macroblock position */
  img->pix_c_y = img->mb_y * img->mb_cr_size_y; /* chroma macroblock position */
  
  /* Define horizontal positions */
  img->block_x = img->mb_x * BLOCK_SIZE;      /* luma block position */
  img->pix_x   = img->mb_x * MB_BLOCK_SIZE;   /* luma pixel position */
  img->pix_c_x = img->mb_x * img->mb_cr_size_x; /* chroma pixel position */

  // 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
  currMB->slice_nr = img->current_slice_nr;
  
  if (img->current_slice_nr >= MAX_NUM_SLICES)
  {
    error ("maximum number of supported slices exceeded, please recompile with increased value for MAX_NUM_SLICES", 200);
  }

  dec_picture->slice_id[img->mb_x][img->mb_y] = img->current_slice_nr;
  if (img->current_slice_nr > dec_picture->max_slice_id)
  {
    dec_picture->max_slice_id=img->current_slice_nr;
  }
  
  CheckAvailabilityOfNeighbors(img);

  // Reset syntax element entries in MB struct
  currMB->qp          = img->qp ;
  currMB->mb_type     = 0;
  currMB->delta_quant = 0;
  currMB->cbp         = 0;
  currMB->cbp_blk     = 0;
  currMB->c_ipred_mode= DC_PRED_8; //GB

  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;

  currMB->cbp_bits   = 0;

  // initialize img->m7 for ABT
  for (j=0; j<MB_BLOCK_SIZE; j++)
    for (i=0; i<MB_BLOCK_SIZE; i++)
      img->m7[i][j] = 0;

  // store filtering parameters for this MB 
  currMB->LFDisableIdc = img->currentSlice->LFDisableIdc;
  currMB->LFAlphaC0Offset = img->currentSlice->LFAlphaC0Offset;
  currMB->LFBetaOffset = img->currentSlice->LFBetaOffset;

}

/*!
 ************************************************************************
 * \brief
 *    set coordinates of the next macroblock
 *    check end_of_slice condition 
 ************************************************************************
 */
int exit_macroblock(struct img_par *img,struct inp_par *inp,int eos_bit)
{
 //! The if() statement below resembles the original code, which tested 
  //! img->current_mb_nr == img->PicSizeInMbs.  Both is, of course, nonsense
  //! In an error prone environment, one can only be sure to have a new
  //! picture by checking the tr of the next slice header!

// printf ("exit_macroblock: FmoGetLastMBOfPicture %d, img->current_mb_nr %d\n", FmoGetLastMBOfPicture(), img->current_mb_nr);
  img->num_dec_mb++;
  
  if (img->num_dec_mb == img->PicSizeInMbs)
//  if (img->current_mb_nr == FmoGetLastMBOfPicture(currSlice->structure))
  {
//thb
/*
    if (currSlice->next_header != EOS)
      currSlice->next_header = SOP;
*/
//the
    assert (nal_startcode_follows (img, inp, eos_bit) == TRUE);
    return TRUE;
  }
  // ask for last mb in the slice  UVLC
  else
  {
// printf ("exit_macroblock: Slice %d old MB %d, now using MB %d\n", img->current_slice_nr, img->current_mb_nr, FmoGetNextMBNr (img->current_mb_nr));

    img->current_mb_nr = FmoGetNextMBNr (img->current_mb_nr);

    if (img->current_mb_nr == -1)     // End of Slice group, MUST be end of slice
    {
      assert (nal_startcode_follows (img, inp, eos_bit) == TRUE);
      return TRUE;
    }

    if(nal_startcode_follows(img, inp, eos_bit) == FALSE) 
      return FALSE;

    if(img->type == I_SLICE  || img->type == SI_SLICE || active_pps->entropy_coding_mode_flag == CABAC)
      return TRUE;
    if(img->cod_counter<=0)
      return TRUE;
    return FALSE;
  }
}

/*!
 ************************************************************************
 * \brief
 *    Interpret the mb mode for P-Frames
 ************************************************************************
 */
void interpret_mb_mode_P(struct img_par *img)
{
  int i;
  const int ICBPTAB[6] = {0,16,32,15,31,47};
  Macroblock *currMB = &img->mb_data[img->current_mb_nr];
  int         mbmode = currMB->mb_type;

#define ZERO_P8x8     (mbmode==5)
#define MODE_IS_P8x8  (mbmode==4 || mbmode==5)
#define MODE_IS_I4x4  (mbmode==6)
#define I16OFFSET     (mbmode-7)
#define MODE_IS_IPCM  (mbmode==31)

  if(mbmode <4)
  {
    currMB->mb_type = mbmode;
    for (i=0;i<4;i++)
    {
      currMB->b8mode[i]   = mbmode;
      currMB->b8pdir[i]   = 0;
    }
  }
  else if(MODE_IS_P8x8)
  {
    currMB->mb_type = P8x8;
    img->allrefzero = ZERO_P8x8;
  }
  else if(MODE_IS_I4x4)
  {
    currMB->mb_type = I4MB;
    for (i=0;i<4;i++)
    {
      currMB->b8mode[i] = IBLOCK;
      currMB->b8pdir[i] = -1;
    }
  }
  else if(MODE_IS_IPCM)
  {
    currMB->mb_type=IPCM;
    
    for (i=0;i<4;i++) 
    {
      currMB->b8mode[i]=0; currMB->b8pdir[i]=-1; 
    }
    currMB->cbp= -1;
    currMB->i16mode = 0;
  }
  else
  {
    currMB->mb_type = I16MB;
    for (i=0;i<4;i++) {currMB->b8mode[i]=0; currMB->b8pdir[i]=-1; }
    currMB->cbp= ICBPTAB[(I16OFFSET)>>2];
    currMB->i16mode = (I16OFFSET) & 0x03;
  }
}

/*!
 ************************************************************************
 * \brief
 *    Interpret the mb mode for I-Frames
 ************************************************************************
 */
void interpret_mb_mode_I(struct img_par *img)
{
  int i;
  const int ICBPTAB[6] = {0,16,32,15,31,47};
  Macroblock *currMB   = &img->mb_data[img->current_mb_nr];
  int         mbmode   = currMB->mb_type;

  if (mbmode==0)
  {
    currMB->mb_type = I4MB;
    for (i=0;i<4;i++) {currMB->b8mode[i]=IBLOCK; currMB->b8pdir[i]=-1; }
  }
  else if(mbmode==25)
  {
    currMB->mb_type=IPCM;

    for (i=0;i<4;i++) {currMB->b8mode[i]=0; currMB->b8pdir[i]=-1; }
    currMB->cbp= -1;
    currMB->i16mode = 0;

  }
  else
  {
    currMB->mb_type = I16MB;
    for (i=0;i<4;i++) {currMB->b8mode[i]=0; currMB->b8pdir[i]=-1; }
    currMB->cbp= ICBPTAB[(mbmode-1)>>2];
    currMB->i16mode = (mbmode-1) & 0x03;
  }
}

/*!
 ************************************************************************
 * \brief
 *    Interpret the mb mode for B-Frames
 ************************************************************************
 */
void interpret_mb_mode_B(struct img_par *img)
{
  static const int offset2pdir16x16[12]   = {0, 0, 1, 2, 0,0,0,0,0,0,0,0};
  static const int offset2pdir16x8[22][2] = {{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},{1,1},{0,0},{0,1},{0,0},{1,0},
                                             {0,0},{0,2},{0,0},{1,2},{0,0},{2,0},{0,0},{2,1},{0,0},{2,2},{0,0}};
  static const int offset2pdir8x16[22][2] = {{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},{1,1},{0,0},{0,1},{0,0},
                                             {1,0},{0,0},{0,2},{0,0},{1,2},{0,0},{2,0},{0,0},{2,1},{0,0},{2,2}};

  const int ICBPTAB[6] = {0,16,32,15,31,47};
  Macroblock *currMB = &img->mb_data[img->current_mb_nr];

  int i, mbmode;
  int mbtype  = currMB->mb_type;
  int *b8mode = currMB->b8mode;
  int *b8pdir = currMB->b8pdir;

  //--- set mbtype, b8type, and b8pdir ---
  if (mbtype==0)       // direct
  {
      mbmode=0;       for(i=0;i<4;i++) {b8mode[i]=0;          b8pdir[i]=2; }
  }
  else if (mbtype==23) // intra4x4
  {
    mbmode=I4MB;    for(i=0;i<4;i++) {b8mode[i]=IBLOCK;     b8pdir[i]=-1; }
  }
  else if ((mbtype>23) && (mbtype<48) ) // intra16x16
  {
    mbmode=I16MB;   for(i=0;i<4;i++) {b8mode[i]=0;          b8pdir[i]=-1; }
    currMB->cbp     = ICBPTAB[(mbtype-24)>>2];
    currMB->i16mode = (mbtype-24) & 0x03;
  }
  else if (mbtype==22) // 8x8(+split)
  {
    mbmode=P8x8;       // b8mode and pdir is transmitted in additional codewords
  }
  else if (mbtype<4)   // 16x16
  {
    mbmode=1;       for(i=0;i<4;i++) {b8mode[i]=1;          b8pdir[i]=offset2pdir16x16[mbtype]; }
  }
  else if(mbtype==48)
  {
    mbmode=IPCM;
    for (i=0;i<4;i++) {currMB->b8mode[i]=0; currMB->b8pdir[i]=-1; }
    currMB->cbp= -1;
    currMB->i16mode = 0;
  }

  else if (mbtype%2==0) // 16x8
  {
    mbmode=2;       for(i=0;i<4;i++) {b8mode[i]=2;          b8pdir[i]=offset2pdir16x8 [mbtype][i/2]; }
  }
  else
  {
    mbmode=3;       for(i=0;i<4;i++) {b8mode[i]=3;          b8pdir[i]=offset2pdir8x16 [mbtype][i%2]; }
  }
  currMB->mb_type = mbmode;
}
/*!
 ************************************************************************
 * \brief
 *    Interpret the mb mode for SI-Frames
 ************************************************************************
 */
void interpret_mb_mode_SI(struct img_par *img)
{
  int i;
  const int ICBPTAB[6] = {0,16,32,15,31,47};
  Macroblock *currMB   = &img->mb_data[img->current_mb_nr];
  int         mbmode   = currMB->mb_type;

  if (mbmode==0)
  {
    currMB->mb_type = SI4MB;
    for (i=0;i<4;i++) {currMB->b8mode[i]=IBLOCK; currMB->b8pdir[i]=-1; }
    img->siblock[img->mb_x][img->mb_y]=1;
  }
  else if (mbmode==1)