macroblock.c

h.264/avc 视频编码程序,实现分数像素匹配功能,非原创.

/*
***********************************************************************
* 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
 *     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]>
 ***********************************************************************
*/

#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 "decodeiff.h"

/*!
 ************************************************************************
 * \brief
 *    Checks the availability of neighboring macroblocks of
 *    the current macroblock for prediction and context determination;
 *    marks the unavailable MBs for intra prediction in the
 *    ipredmode-array by -1. Only neighboring MBs in the causal
 *    past of the current MB are checked.
 ************************************************************************
 */
void CheckAvailabilityOfNeighbors(struct img_par *img)
{
  int i,j;
  const int mb_width = img->width/MB_BLOCK_SIZE;
  const int mb_nr = img->current_mb_nr;
  Macroblock *currMB = &img->mb_data[mb_nr];

  // mark all neighbors as unavailable
  for (i=0; i<3; i++)
    for (j=0; j<3; j++)
      img->mb_data[mb_nr].mb_available[i][j]=NULL;
  img->mb_data[mb_nr].mb_available[1][1]=currMB; // current MB

  // Check MB to the left
  if(img->pix_x >= MB_BLOCK_SIZE)
  {
    int remove_prediction = currMB->slice_nr != img->mb_data[mb_nr-1].slice_nr;
    // upper blocks
    if (remove_prediction || (img->UseConstrainedIntraPred && img->intra_block[mb_nr-1][1]==0))
    {
      img->ipredmode[img->block_x][img->block_y+1] = -1;
      img->ipredmode[img->block_x][img->block_y+2] = -1;
    }
    // lower blocks
    if (remove_prediction || (img->UseConstrainedIntraPred && img->intra_block[mb_nr-1][3]==0))
    {
      img->ipredmode[img->block_x][img->block_y+3] = -1;
      img->ipredmode[img->block_x][img->block_y+4] = -1;
    }
    if (!remove_prediction)
    {
      currMB->mb_available[1][0]=&(img->mb_data[mb_nr-1]);
    }
  }


  // Check MB above
  if(img->pix_y >= MB_BLOCK_SIZE)
  {
    int remove_prediction = currMB->slice_nr != img->mb_data[mb_nr-mb_width].slice_nr;
    // upper blocks
    if (remove_prediction || (img->UseConstrainedIntraPred && img->intra_block[mb_nr-mb_width][2]==0))
    {
      img->ipredmode[img->block_x+1][img->block_y] = -1;
      img->ipredmode[img->block_x+2][img->block_y] = -1;
    }
    // lower blocks
    if (remove_prediction || (img->UseConstrainedIntraPred && img->intra_block[mb_nr-mb_width][3]==0))
    {
      img->ipredmode[img->block_x+3][img->block_y] = -1;
      img->ipredmode[img->block_x+4][img->block_y] = -1;
    }
    if (!remove_prediction)
    {
      currMB->mb_available[0][1]=&(img->mb_data[mb_nr-mb_width]);
    }
  }

  // Check MB left above
  if(img->pix_x >= MB_BLOCK_SIZE && img->pix_y  >= MB_BLOCK_SIZE )
  {
    if(currMB->slice_nr == img->mb_data[mb_nr-mb_width-1].slice_nr)
      img->mb_data[mb_nr].mb_available[0][0]=&(img->mb_data[mb_nr-mb_width-1]);
  }

  // Check MB right above
  if(img->pix_y >= MB_BLOCK_SIZE && img->pix_x < (img->width-MB_BLOCK_SIZE ))
  {
    if(currMB->slice_nr == img->mb_data[mb_nr-mb_width+1].slice_nr)
      currMB->mb_available[0][2]=&(img->mb_data[mb_nr-mb_width+1]);
  }
}

/*!
 ************************************************************************
 * \brief
 *    initializes the current macroblock
 ************************************************************************
 */
void start_macroblock(struct img_par *img,struct inp_par *inp)
{
  int i,j,k,l;
  Macroblock *currMB = &img->mb_data[img->current_mb_nr];

  // WYK: Oct. 8, 2001, start ...
  // The following is moved and modified from exit_macroblock(), 
  // to make the decoding process correct when some macroblocks are lost
  /* Update coordinates of the current macroblock */
  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 * MB_BLOCK_SIZE/2; /* 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 * MB_BLOCK_SIZE/2; /* chroma pixel position */
  //WYK: Oct. 8, 2001, ... end

  // 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 MB is next to a slice boundary, mark neighboring blocks unavailable for prediction
  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;

  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;

  for (j=0; j < BLOCK_MULTIPLE; j++)
    for (i=0; i < BLOCK_MULTIPLE; i++)
      currMB->coeffs_count[j][i] = 0;
}

/*!
 ************************************************************************
 * \brief
 *    set coordinates of the next macroblock
 *    check end_of_slice condition (have to implement)
 ************************************************************************
 */
int exit_macroblock(struct img_par *img,struct inp_par *inp)
{
  const int number_mb_per_row = img->width / MB_BLOCK_SIZE ;
  Slice *currSlice = img->currentSlice;

  // Update coordinates of the next 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;      // luma block position
  img->pix_y   = img->mb_y * MB_BLOCK_SIZE;   // luma macroblock position
  img->pix_c_y = img->mb_y * MB_BLOCK_SIZE/2; // 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 * MB_BLOCK_SIZE/2; // chroma pixel position

  if (img->current_mb_nr == img->max_mb_nr)
  {
    if (currSlice->next_header != EOS)
      currSlice->next_header = SOP;
    return TRUE;
  }
  // ask for last mb in the slice  UVLC
  else
  {
    if(nal_startcode_follows(img, inp) == FALSE) return FALSE;
    if(img->type == INTRA_IMG || img->type == SP_IMG_1|| img->type == SP_IMG_MULT || inp->symbol_mode == 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)

  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;
    // b8mode and pdir are read and set later
  }
  else if(MODE_IS_I4x4)
  {
    currMB->mb_type = I4MB;
    for (i=0;i<4;i++) {currMB->b8mode[i]=IBLOCK; currMB->b8pdir[i]=-1; }
  }
  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
  {
    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) // 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%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
 *    init macroblock I and P frames
 ************************************************************************
 */
void init_macroblock(struct img_par *img)
{
  int i,j;
  int predframe_no;