/*!
 ***********************************************************************
 *  \file
 *      block.c
 *
 *  \brief
 *      Block functions
 *
 *  \author
 *      Main contributors (see contributors.h for copyright, address and affiliation details)
 *      - Inge Lille-Lang鴜          <inge.lille-langoy@telenor.com>
 *      - Rickard Sjoberg            <rickard.sjoberg@era.ericsson.se>
 ***********************************************************************
 */

#include "contributors.h"

#include <stdlib.h>

#include "global.h"
#include "block.h"
#include "image.h"
#include "mb_access.h"


#define Q_BITS          15

static const int quant_coef[6][4][4] = {
  {{13107, 8066,13107, 8066},{ 8066, 5243, 8066, 5243},{13107, 8066,13107, 8066},{ 8066, 5243, 8066, 5243}},
  {{11916, 7490,11916, 7490},{ 7490, 4660, 7490, 4660},{11916, 7490,11916, 7490},{ 7490, 4660, 7490, 4660}},
  {{10082, 6554,10082, 6554},{ 6554, 4194, 6554, 4194},{10082, 6554,10082, 6554},{ 6554, 4194, 6554, 4194}},
  {{ 9362, 5825, 9362, 5825},{ 5825, 3647, 5825, 3647},{ 9362, 5825, 9362, 5825},{ 5825, 3647, 5825, 3647}},
  {{ 8192, 5243, 8192, 5243},{ 5243, 3355, 5243, 3355},{ 8192, 5243, 8192, 5243},{ 5243, 3355, 5243, 3355}},
  {{ 7282, 4559, 7282, 4559},{ 4559, 2893, 4559, 2893},{ 7282, 4559, 7282, 4559},{ 4559, 2893, 4559, 2893}}
};
static const int A[4][4] = {
  { 16, 20, 16, 20},
  { 20, 25, 20, 25},
  { 16, 20, 16, 20},
  { 20, 25, 20, 25}
};

// Notation for comments regarding prediction and predictors.
// The pels of the 4x4 block are labelled a..p. The predictor pels above
// are labelled A..H, from the left I..L, and from above left X, as follows:
//
//  X A B C D E F G H
//  I a b c d
//  J e f g h
//  K i j k l
//  L m n o p
//

// Predictor array index definitions
#define P_X (PredPel[0])
#define P_A (PredPel[1])
#define P_B (PredPel[2])
#define P_C (PredPel[3])
#define P_D (PredPel[4])
#define P_E (PredPel[5])
#define P_F (PredPel[6])
#define P_G (PredPel[7])
#define P_H (PredPel[8])
#define P_I (PredPel[9])
#define P_J (PredPel[10])
#define P_K (PredPel[11])
#define P_L (PredPel[12])

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 4x4 blocks with all 5 intra prediction modes
 *
 * \return
 *    DECODING_OK   decoding of intraprediction mode was sucessfull            \n
 *    SEARCH_SYNC   search next sync element as errors while decoding occured
 ***********************************************************************
 */

int intrapred(
  struct img_par *img,  //!< image parameters
  int ioff,             //!< pixel offset X within MB
  int joff,             //!< pixel offset Y within MB
  int img_block_x,      //!< location of block X, multiples of 4
  int img_block_y)      //!< location of block Y, multiples of 4
{
  int i,j;
  int s0;
  int img_y,img_x;
  int PredPel[13];  // array of predictor pels

  byte **imgY = dec_picture->imgY;

  PixelPos pix_a[4];
  PixelPos pix_b, pix_c, pix_d;

  int block_available_up;
  int block_available_left;
  int block_available_up_left;
  int block_available_up_right;

  int mb_nr=img->current_mb_nr;

  byte predmode = img->ipredmode[img_block_x][img_block_y];

  img_x=img_block_x*4;
  img_y=img_block_y*4;

  for (i=0;i<4;i++)
  {
    getNeighbour(mb_nr, ioff -1 , joff +i , 1, &pix_a[i]);
  }
  
  
  getNeighbour(mb_nr, ioff    , joff -1 , 1, &pix_b);
  getNeighbour(mb_nr, ioff +4 , joff -1 , 1, &pix_c);
  getNeighbour(mb_nr, ioff -1 , joff -1 , 1, &pix_d);

  pix_c.available = pix_c.available && !(((ioff==4)||(ioff==12)) && ((joff==4)||(joff==12)));

  if (active_pps->constrained_intra_pred_flag)
  {
    for (i=0, block_available_left=1; i<4;i++)
      block_available_left  &= pix_a[i].available ? img->intra_block[pix_a[i].mb_addr]: 0;
    block_available_up       = pix_b.available ? img->intra_block [pix_b.mb_addr] : 0;
    block_available_up_right = pix_c.available ? img->intra_block [pix_c.mb_addr] : 0;
    block_available_up_left  = pix_d.available ? img->intra_block [pix_d.mb_addr] : 0;
  }
  else
  {
    block_available_left     = pix_a[0].available;
    block_available_up       = pix_b.available;
    block_available_up_right = pix_c.available;
    block_available_up_left  = pix_d.available;
  }

  // form predictor pels
  if (block_available_up)
  {
    P_A = imgY[pix_b.pos_y][pix_b.pos_x+0];
    P_B = imgY[pix_b.pos_y][pix_b.pos_x+1];
    P_C = imgY[pix_b.pos_y][pix_b.pos_x+2];
    P_D = imgY[pix_b.pos_y][pix_b.pos_x+3];

  }
  else
  {
    P_A = P_B = P_C = P_D = 128;
  }

  if (block_available_up_right)
  {
    P_E = imgY[pix_c.pos_y][pix_c.pos_x+0];
    P_F = imgY[pix_c.pos_y][pix_c.pos_x+1];
    P_G = imgY[pix_c.pos_y][pix_c.pos_x+2];
    P_H = imgY[pix_c.pos_y][pix_c.pos_x+3];
  }
  else
  {
    P_E = P_F = P_G = P_H = P_D;
  }

  if (block_available_left)
  {
    P_I = imgY[pix_a[0].pos_y][pix_a[0].pos_x];
    P_J = imgY[pix_a[1].pos_y][pix_a[1].pos_x];
    P_K = imgY[pix_a[2].pos_y][pix_a[2].pos_x];
    P_L = imgY[pix_a[3].pos_y][pix_a[3].pos_x];
  }
  else
  {
    P_I = P_J = P_K = P_L = 128;
  }

  if (block_available_up_left)
  {
    P_X = imgY[pix_d.pos_y][pix_d.pos_x];
  }
  else
  {
    P_X = 128;
  }

  
  switch (predmode)
  {
  case DC_PRED:                         /* DC prediction */

    s0 = 0;
    if (block_available_up && block_available_left)
    {   
      // no edge
      s0 = (P_A + P_B + P_C + P_D + P_I + P_J + P_K + P_L + 4)/(2*BLOCK_SIZE);
    }
    else if (!block_available_up && block_available_left)
    {
      // upper edge
      s0 = (P_I + P_J + P_K + P_L + 2)/BLOCK_SIZE;             
    }
    else if (block_available_up && !block_available_left)
    {
      // left edge
      s0 = (P_A + P_B + P_C + P_D + 2)/BLOCK_SIZE;             
    }
    else //if (!block_available_up && !block_available_left)
    {
      // top left corner, nothing to predict from
      s0 = 128;                           
    }

    for (j=0; j < BLOCK_SIZE; j++)
    {
      for (i=0; i < BLOCK_SIZE; i++)
      {
        // store DC prediction
        img->mpr[i+ioff][j+joff] = s0;
      }
    }
    break;

  case VERT_PRED:                       /* vertical prediction from block above */
    if (!block_available_up)
      printf ("warning: Intra_4x4_Vertical prediction mode not allowed at mb %d\n",img->current_mb_nr);

    for(j=0;j<BLOCK_SIZE;j++)
      for(i=0;i<BLOCK_SIZE;i++)
        img->mpr[i+ioff][j+joff]=imgY[pix_b.pos_y][pix_b.pos_x+i];/* store predicted 4x4 block */
    break;

  case HOR_PRED:                        /* horizontal prediction from left block */
    if (!block_available_left)
      printf ("warning: Intra_4x4_Horizontal prediction mode not allowed at mb %d\n",img->current_mb_nr);

    for(j=0;j<BLOCK_SIZE;j++)
      for(i=0;i<BLOCK_SIZE;i++)
        img->mpr[i+ioff][j+joff]=imgY[pix_a[j].pos_y][pix_a[j].pos_x]; /* store predicted 4x4 block */
    break;

  case DIAG_DOWN_RIGHT_PRED:
    if ((!block_available_up)||(!block_available_left)||(!block_available_up_left))
      printf ("warning: Intra_4x4_Diagonal_Down_Right prediction mode not allowed at mb %d\n",img->current_mb_nr);

    img->mpr[0+ioff][3+joff] = (P_L + 2*P_K + P_J + 2) / 4; 
    img->mpr[0+ioff][2+joff] =
    img->mpr[1+ioff][3+joff] = (P_K + 2*P_J + P_I + 2) / 4; 
    img->mpr[0+ioff][1+joff] =
    img->mpr[1+ioff][2+joff] = 
    img->mpr[2+ioff][3+joff] = (P_J + 2*P_I + P_X + 2) / 4; 
    img->mpr[0+ioff][0+joff] =
    img->mpr[1+ioff][1+joff] =
    img->mpr[2+ioff][2+joff] =
    img->mpr[3+ioff][3+joff] = (P_I + 2*P_X + P_A + 2) / 4; 
    img->mpr[1+ioff][0+joff] =
    img->mpr[2+ioff][1+joff] =
    img->mpr[3+ioff][2+joff] = (P_X + 2*P_A + P_B + 2) / 4;
    img->mpr[2+ioff][0+joff] =
    img->mpr[3+ioff][1+joff] = (P_A + 2*P_B + P_C + 2) / 4;
    img->mpr[3+ioff][0+joff] = (P_B + 2*P_C + P_D + 2) / 4;
    break;

  case DIAG_DOWN_LEFT_PRED:
    if (!block_available_up)
      printf ("warning: Intra_4x4_Diagonal_Down_Left prediction mode not allowed at mb %d\n",img->current_mb_nr);

    img->mpr[0+ioff][0+joff] = (P_A + P_C + 2*(P_B) + 2) / 4;
    img->mpr[1+ioff][0+joff] = 
    img->mpr[0+ioff][1+joff] = (P_B + P_D + 2*(P_C) + 2) / 4;
    img->mpr[2+ioff][0+joff] =
    img->mpr[1+ioff][1+joff] =
    img->mpr[0+ioff][2+joff] = (P_C + P_E + 2*(P_D) + 2) / 4;
    img->mpr[3+ioff][0+joff] = 
    img->mpr[2+ioff][1+joff] = 
    img->mpr[1+ioff][2+joff] = 
    img->mpr[0+ioff][3+joff] = (P_D + P_F + 2*(P_E) + 2) / 4;
    img->mpr[3+ioff][1+joff] = 
    img->mpr[2+ioff][2+joff] = 
    img->mpr[1+ioff][3+joff] = (P_E + P_G + 2*(P_F) + 2) / 4;
    img->mpr[3+ioff][2+joff] = 
    img->mpr[2+ioff][3+joff] = (P_F + P_H + 2*(P_G) + 2) / 4;
    img->mpr[3+ioff][3+joff] = (P_G + 3*(P_H) + 2) / 4;
    break;

  case  VERT_RIGHT_PRED:/* diagonal prediction -22.5 deg to horizontal plane */
    if ((!block_available_up)||(!block_available_left)||(!block_available_up_left))
      printf ("warning: Intra_4x4_Vertical_Right prediction mode not allowed at mb %d\n",img->current_mb_nr);

    img->mpr[0+ioff][0+joff] = 
    img->mpr[1+ioff][2+joff] = (P_X + P_A + 1) / 2;
    img->mpr[1+ioff][0+joff] = 
    img->mpr[2+ioff][2+joff] = (P_A + P_B + 1) / 2;
    img->mpr[2+ioff][0+joff] = 
    img->mpr[3+ioff][2+joff] = (P_B + P_C + 1) / 2;
    img->mpr[3+ioff][0+joff] = (P_C + P_D + 1) / 2;
    img->mpr[0+ioff][1+joff] = 
    img->mpr[1+ioff][3+joff] = (P_I + 2*P_X + P_A + 2) / 4;
    img->mpr[1+ioff][1+joff] = 
    img->mpr[2+ioff][3+joff] = (P_X + 2*P_A + P_B + 2) / 4;
    img->mpr[2+ioff][1+joff] = 
    img->mpr[3+ioff][3+joff] = (P_A + 2*P_B + P_C + 2) / 4;
    img->mpr[3+ioff][1+joff] = (P_B + 2*P_C + P_D + 2) / 4;
    img->mpr[0+ioff][2+joff] = (P_X + 2*P_I + P_J + 2) / 4;
    img->mpr[0+ioff][3+joff] = (P_I + 2*P_J + P_K + 2) / 4;
    break;

  case  VERT_LEFT_PRED:/* diagonal prediction -22.5 deg to horizontal plane */
    if (!block_available_up)
      printf ("warning: Intra_4x4_Vertical_Left prediction mode not allowed at mb %d\n",img->current_mb_nr);
    
    img->mpr[0+ioff][0+joff] = (P_A + P_B + 1) / 2;
    img->mpr[1+ioff][0+joff] = 
    img->mpr[0+ioff][2+joff] = (P_B + P_C + 1) / 2;
    img->mpr[2+ioff][0+joff] = 
    img->mpr[1+ioff][2+joff] = (P_C + P_D + 1) / 2;
    img->mpr[3+ioff][0+joff] = 
    img->mpr[2+ioff][2+joff] = (P_D + P_E + 1) / 2;
    img->mpr[3+ioff][2+joff] = (P_E + P_F + 1) / 2;
    img->mpr[0+ioff][1+joff] = (P_A + 2*P_B + P_C + 2) / 4;
    img->mpr[1+ioff][1+joff] = 
    img->mpr[0+ioff][3+joff] = (P_B + 2*P_C + P_D + 2) / 4;
    img->mpr[2+ioff][1+joff] = 
    img->mpr[1+ioff][3+joff] = (P_C + 2*P_D + P_E + 2) / 4;
    img->mpr[3+ioff][1+joff] = 
    img->mpr[2+ioff][3+joff] = (P_D + 2*P_E + P_F + 2) / 4;
    img->mpr[3+ioff][3+joff] = (P_E + 2*P_F + P_G + 2) / 4;
    break;

  case  HOR_UP_PRED:/* diagonal prediction -22.5 deg to horizontal plane */
    if (!block_available_left)
      printf ("warning: Intra_4x4_Horizontal_Up prediction mode not allowed at mb %d\n",img->current_mb_nr);
    
    img->mpr[0+ioff][0+joff] = (P_I + P_J + 1) / 2;
    img->mpr[1+ioff][0+joff] = (P_I + 2*P_J + P_K + 2) / 4;
    img->mpr[2+ioff][0+joff] = 
    img->mpr[0+ioff][1+joff] = (P_J + P_K + 1) / 2;
    img->mpr[3+ioff][0+joff] = 
    img->mpr[1+ioff][1+joff] = (P_J + 2*P_K + P_L + 2) / 4;
    img->mpr[2+ioff][1+joff] = 
    img->mpr[0+ioff][2+joff] = (P_K + P_L + 1) / 2;
    img->mpr[3+ioff][1+joff] = 
    img->mpr[1+ioff][2+joff] = (P_K + 2*P_L + P_L + 2) / 4;
    img->mpr[3+ioff][2+joff] = 
    img->mpr[1+ioff][3+joff] = 
    img->mpr[0+ioff][3+joff] = 
    img->mpr[2+ioff][2+joff] = 
    img->mpr[2+ioff][3+joff] = 
    img->mpr[3+ioff][3+joff] = P_L;
    break;

  case  HOR_DOWN_PRED:/* diagonal prediction -22.5 deg to horizontal plane */
    if ((!block_available_up)||(!block_available_left)||(!block_available_up_left))
      printf ("warning: Intra_4x4_Horizontal_Down prediction mode not allowed at mb %d\n",img->current_mb_nr);

    img->mpr[0+ioff][0+joff] = 
    img->mpr[2+ioff][1+joff] = (P_X + P_I + 1) / 2;
    img->mpr[1+ioff][0+joff] = 
    img->mpr[3+ioff][1+joff] = (P_I + 2*P_X + P_A + 2) / 4;
    img->mpr[2+ioff][0+joff] = (P_X + 2*P_A + P_B + 2) / 4;
    img->mpr[3+ioff][0+joff] = (P_A + 2*P_B + P_C + 2) / 4;
    img->mpr[0+ioff][1+joff] = 
    img->mpr[2+ioff][2+joff] = (P_I + P_J + 1) / 2;
    img->mpr[1+ioff][1+joff] = 
    img->mpr[3+ioff][2+joff] = (P_X + 2*P_I + P_J + 2) / 4;
    img->mpr[0+ioff][2+joff] = 
    img->mpr[2+ioff][3+joff] = (P_J + P_K + 1) / 2;
    img->mpr[1+ioff][2+joff] = 
    img->mpr[3+ioff][3+joff] = (P_I + 2*P_J + P_K + 2) / 4;
    img->mpr[0+ioff][3+joff] = (P_K + P_L + 1) / 2;
    img->mpr[1+ioff][3+joff] = (P_J + 2*P_K + P_L + 2) / 4;
    break;

  default:
    printf("Error: illegal intra_4x4 prediction mode: %d\n",predmode);
    return SEARCH_SYNC;
    break;
  }

  return DECODING_OK;
}


/*!
 ***********************************************************************
 * \return
 *    best SAD
 ***********************************************************************
 */
int intrapred_luma_16x16(struct img_par *img, //!< image parameters
                         int predmode)        //!< prediction mode