/*!
 *************************************************************************************
 * \file intra4x4_pred.c
 *
 * \brief
 *    Functions for intra 4x4 prediction
 *
 * \author
 *      Main contributors (see contributors.h for copyright, 
 *                         address and affiliation details)
 *      - Alexis Michael Tourapis  <alexismt@ieee.org>
 *
 *************************************************************************************
 */
#include "global.h"
#include "intra4x4_pred.h"
#include "mb_access.h"
#include "image.h"

// 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])

static void memset_4x4(h264_imgpel_macroblock_row_t *mb_pred, int offset_x, int pred)
{
#ifdef _M_IX86
	// benski> can't believe the shitty code that the compiler generated...  this code is better
	int dword_pred = pred * 0x01010101;
	mb_pred = (h264_imgpel_macroblock_row_t *)&mb_pred[0][offset_x];
	*(int *)mb_pred[0] = dword_pred;
	*(int *)mb_pred[1] = dword_pred;
	*(int *)mb_pred[2] = dword_pred;
	*(int *)mb_pred[3] = dword_pred;
#else
	int ii, jj;
	for (jj = 0; jj < BLOCK_SIZE; jj++)
	{
		for (ii = 0; ii < BLOCK_SIZE; ii++)
		{
			mb_pred[jj][offset_x+ii]=(imgpel) pred;
		}
	}
#endif
}

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 4x4 DC prediction mode
 *
 * \param currMB
 *    current MB structure
 * \param pl
 *    color plane
 * \param ioff
 *    pixel offset X within MB
 * \param joff
 *    pixel offset Y within MB
 * \return
 *    DECODING_OK   decoding of intra prediction mode was successful            \n
 *
 ***********************************************************************
 */
static inline int intra4x4_dc_pred(Macroblock *currMB, 
                                   ColorPlane pl,               
                                   int ioff,
                                   int joff)
{
  Slice *currSlice = currMB->p_Slice;
  VideoParameters *p_Vid = currMB->p_Vid;  

  int i;
  int s0 = 0;  
  imgpel **imgY = (pl) ? p_Vid->dec_picture->imgUV[pl - 1]->img : p_Vid->dec_picture->imgY->img;

  PixelPos pix_a[4], pix_b;

  int block_available_up;
  int block_available_left;  

  p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +0 , &pix_a[0]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +1 , &pix_a[1]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +2 , &pix_a[2]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +3 , &pix_a[3]);
  p_Vid->getNeighbourPXLumaNB(currMB, ioff    , joff -1 , &pix_b);

  if (p_Vid->active_pps->constrained_intra_pred_flag)
  {
    for (i=0, block_available_left=1; i<4;++i)
      block_available_left  &= pix_a[i].available ? p_Vid->intra_block[pix_a[i].mb_addr]: 0;
    block_available_up       = pix_b.available ? p_Vid->intra_block [pix_b.mb_addr] : 0;
  }
  else
  {
    block_available_left     = pix_a[0].available;
    block_available_up       = pix_b.available;
  }
	// TODO:  ippiPredictIntra_4x4_H264_8u_C1IR
  // form predictor pels
  if (block_available_up)
  {
    s0 += imgY[pix_b.pos_y][pix_b.pos_x + 0];
    s0 += imgY[pix_b.pos_y][pix_b.pos_x + 1];
    s0 += imgY[pix_b.pos_y][pix_b.pos_x + 2];
    s0 += imgY[pix_b.pos_y][pix_b.pos_x + 3];
  }

  if (block_available_left)
  {
    s0 += imgY[pix_a[0].pos_y][pix_a[0].pos_x];
    s0 += imgY[pix_a[1].pos_y][pix_a[1].pos_x];
    s0 += imgY[pix_a[2].pos_y][pix_a[2].pos_x];
    s0 += imgY[pix_a[3].pos_y][pix_a[3].pos_x];
  }

  if (block_available_up && block_available_left)
  {
    // no edge
    s0 = (s0 + 4)>>3;
  }
  else if (!block_available_up && block_available_left)
  {
    // upper edge
    s0 = (s0 + 2)>>2;
  }
  else if (block_available_up && !block_available_left)
  {
    // left edge
    s0 = (s0 + 2)>>2;
  }
  else //if (!block_available_up && !block_available_left)
  {
    // top left corner, nothing to predict from
    s0 = p_Vid->dc_pred_value_comp[pl];
  }

	memset_4x4(&currSlice->mb_pred[pl][joff], ioff, s0);
  return DECODING_OK;
}

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 4x4 vertical prediction mode
 *
 * \return
 *    DECODING_OK   decoding of intraprediction mode was sucessfull            \n
 *
 ***********************************************************************
 */
static inline int intra4x4_vert_pred(Macroblock *currMB,    //!< current macroblock
                                     ColorPlane pl,         //!< current image plane
                                     int ioff,              //!< pixel offset X within MB
                                     int joff)              //!< pixel offset Y within MB
{
  Slice *currSlice = currMB->p_Slice;
  VideoParameters *p_Vid = currMB->p_Vid;
  
  imgpel **imgY = (pl) ? p_Vid->dec_picture->imgUV[pl - 1]->img : p_Vid->dec_picture->imgY->img;
  imgpel *src;
  PixelPos pix_b;

  p_Vid->getNeighbourPXLumaNB(currMB, ioff, joff - 1 ,  &pix_b);
#ifdef H264_WARNINGS
	{
		  int block_available_up;

  if (p_Vid->active_pps->constrained_intra_pred_flag)
  {
    block_available_up = pix_b.available ? p_Vid->intra_block [pix_b.mb_addr] : 0;
  }
  else
  {
    block_available_up = pix_b.available;
  }
	
  if (!block_available_up)
    printf ("warning: Intra_4x4_Vertical prediction mode not allowed at mb %d\n", (int) p_Vid->current_mb_nr);
	}
#endif
	src = &(imgY[pix_b.pos_y][pix_b.pos_x]);
  /* store predicted 4x4 block */
    memcpy(&(currSlice->mb_pred[pl][joff][ioff]), src, BLOCK_SIZE * sizeof(imgpel));
		memcpy(&(currSlice->mb_pred[pl][joff+1][ioff]), src, BLOCK_SIZE * sizeof(imgpel));
		memcpy(&(currSlice->mb_pred[pl][joff+2][ioff]), src, BLOCK_SIZE * sizeof(imgpel));
		memcpy(&(currSlice->mb_pred[pl][joff+3][ioff]), src, BLOCK_SIZE * sizeof(imgpel));

  return DECODING_OK;
}

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 4x4 horizontal prediction mode
 *
 * \param currMB
 *    current MB structure
 * \param pl
 *    color plane
 * \param ioff
 *    pixel offset X within MB
 * \param joff
 *    pixel offset Y within MB
 *
 * \return
 *    DECODING_OK   decoding of intra prediction mode was successful
 *
 ***********************************************************************
 */
static inline int intra4x4_hor_pred(Macroblock *currMB, 
                                    ColorPlane pl,               
                                    int ioff,
                                    int joff)
{
  VideoParameters *p_Vid = currMB->p_Vid;
  Slice *currSlice = currMB->p_Slice;

  int j;
  imgpel **imgY = (pl) ? p_Vid->dec_picture->imgUV[pl - 1]->img : p_Vid->dec_picture->imgY->img;

  PixelPos pix_a[4];

  imgpel prediction;    

	p_Vid->getNeighbourXPLumaNB(currMB, ioff - 1 , joff + 0 ,  &pix_a[0]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff - 1 , joff + 1 ,  &pix_a[1]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff - 1 , joff + 2 ,  &pix_a[2]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff - 1 , joff + 3 ,  &pix_a[3]);

#ifdef H264_WARNINGS
	{
		int i;
		int block_available_left;

		if (p_Vid->active_pps->constrained_intra_pred_flag)
		{
			for (i=0, block_available_left=1; i<4;++i)
				block_available_left  &= pix_a[i].available ? p_Vid->intra_block[pix_a[i].mb_addr]: 0;
		}
		else
		{
			block_available_left     = pix_a[0].available;
		}

		if (!block_available_left)
			printf ("warning: Intra_4x4_Horizontal prediction mode not allowed at mb %d\n",(int) p_Vid->current_mb_nr);
	}
#endif
  for(j=0;j<BLOCK_SIZE;++j)
  {
		// TODO: write using imgY's stride
    prediction = imgY[pix_a[j].pos_y][pix_a[j].pos_x];
    //for(i = ioff;i < ioff + BLOCK_SIZE;++i)
      currSlice->mb_pred[pl][j+joff][ioff]= prediction; /* store predicted 4x4 block */
		currSlice->mb_pred[pl][j+joff][ioff+1]= prediction; /* store predicted 4x4 block */
		currSlice->mb_pred[pl][j+joff][ioff+2]= prediction; /* store predicted 4x4 block */
		currSlice->mb_pred[pl][j+joff][ioff+3]= prediction; /* store predicted 4x4 block */
  }

  return DECODING_OK;
}

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 4x4 diagonal down right prediction mode
 *
 * \return
 *    DECODING_OK   decoding of intraprediction mode was sucessfull            \n
 *
 ***********************************************************************
 */
static inline int intra4x4_diag_down_right_pred(Macroblock *currMB,    //!< current macroblock
                                                ColorPlane pl,         //!< current image plane
                                                int ioff,              //!< pixel offset X within MB
                                                int joff)              //!< pixel offset Y within MB
{
  Slice *currSlice = currMB->p_Slice;
  VideoParameters *p_Vid = currMB->p_Vid;
  
  
  imgpel PredPel[13];  // array of predictor pels
  imgpel **imgY = (pl) ? p_Vid->dec_picture->imgUV[pl - 1]->img : p_Vid->dec_picture->imgY->img;

  PixelPos pix_a[4];
  PixelPos pix_b, pix_d;

  

	p_Vid->getNeighbourXPLumaNB(currMB, ioff - 1 , joff + 0 ,  &pix_a[0]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff - 1 , joff + 1 ,  &pix_a[1]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff - 1 , joff + 2 ,  &pix_a[2]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff - 1 , joff + 3 ,  &pix_a[3]);

  p_Vid->getNeighbourPXLumaNB(currMB, ioff    , joff -1 ,  &pix_b);
  p_Vid->getNeighbourLuma(currMB, ioff -1 , joff -1 ,  &pix_d);
#ifdef H264_WARNINGS
	{
		int block_available_up;
  int block_available_left;
  int block_available_up_left;
  if (p_Vid->active_pps->constrained_intra_pred_flag)
  {
		int i;
    for (i=0, block_available_left=1; i<4;++i)
      block_available_left  &= pix_a[i].available ? p_Vid->intra_block[pix_a[i].mb_addr]: 0;
    block_available_up       = pix_b.available ? p_Vid->intra_block [pix_b.mb_addr] : 0;
    block_available_up_left  = pix_d.available ? p_Vid->intra_block [pix_d.mb_addr] : 0;
  }
  else
  {
    block_available_left     = pix_a[0].available;
    block_available_up       = pix_b.available;
    block_available_up_left  = pix_d.available;
  }

  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",(int) p_Vid->current_mb_nr);
}
#endif
  // form predictor pels
  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];

  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];

  P_X = imgY[pix_d.pos_y][pix_d.pos_x];

  currSlice->mb_pred[pl][joff+3][ioff+0] = (imgpel) ((P_L + 2*P_K + P_J + 2) >> 2);
  currSlice->mb_pred[pl][joff+2][ioff+0] =
  currSlice->mb_pred[pl][joff+3][ioff+1] = (imgpel) ((P_K + 2*P_J + P_I + 2) >> 2);
  currSlice->mb_pred[pl][joff+1][ioff+0] =
  currSlice->mb_pred[pl][joff+2][ioff+1] =
  currSlice->mb_pred[pl][joff+3][ioff+2] = (imgpel) ((P_J + 2*P_I + P_X + 2) >> 2);
  currSlice->mb_pred[pl][joff+0][ioff+0] =
  currSlice->mb_pred[pl][joff+1][ioff+1] =
  currSlice->mb_pred[pl][joff+2][ioff+2] =
  currSlice->mb_pred[pl][joff+3][ioff+3] = (imgpel) ((P_I + 2*P_X + P_A + 2) >> 2);
  currSlice->mb_pred[pl][joff+0][ioff+1] =
  currSlice->mb_pred[pl][joff+1][ioff+2] =
  currSlice->mb_pred[pl][joff+2][ioff+3] = (imgpel) ((P_X + 2*P_A + P_B + 2) >> 2);
  currSlice->mb_pred[pl][joff+0][ioff+2] =
  currSlice->mb_pred[pl][joff+1][ioff+3] = (imgpel) ((P_A + 2*P_B + P_C + 2) >> 2);
  currSlice->mb_pred[pl][joff+0][ioff+3] = (imgpel) ((P_B + 2*P_C + P_D + 2) >> 2);

  return DECODING_OK;
}

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 4x4 diagonal down left prediction mode
 *
 * \return
 *    DECODING_OK   decoding of intraprediction mode was sucessfull            \n
 *
 ***********************************************************************
 */
static inline int intra4x4_diag_down_left_pred(Macroblock *currMB,    //!< current macroblock
                                               ColorPlane pl,         //!< current image plane
                                               int ioff,              //!< pixel offset X within MB
                                               int joff)              //!< pixel offset Y within MB
{
  Slice *currSlice = currMB->p_Slice;
  VideoParameters *p_Vid = currMB->p_Vid;
  int block_available_up_right;
		#ifdef H264_WARNINGS
		int block_available_up;
#endif
  imgpel PredPel[13];  // array of predictor pels
  imgpel **imgY = (pl) ? p_Vid->dec_picture->imgUV[pl - 1]->img : p_Vid->dec_picture->imgY->img;

  PixelPos pix_b, pix_c;

  p_Vid->getNeighbourPXLumaNB(currMB, ioff    , joff - 1,  &pix_b);
  p_Vid->getNeighbourLuma(currMB, ioff + 4, joff - 1,  &pix_c);

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

	
	
  if (p_Vid->active_pps->constrained_intra_pred_flag)
  {
		#ifdef H264_WARNINGS
    block_available_up       = pix_b.available ? p_Vid->intra_block [pix_b.mb_addr] : 0;
#endif
    block_available_up_right = pix_c.available ? p_Vid->intra_block [pix_c.mb_addr] : 0;
  }
  else
  {
		#ifdef H264_WARNINGS
    block_available_up       = pix_b.available;
#endif
    block_available_up_right = pix_c.available;
  }
#ifdef H264_WARNINGS
  if (!block_available_up)
    printf ("warning: Intra_4x4_Diagonal_Down_Left prediction mode not allowed at mb %d\n", (int) p_Vid->current_mb_nr);

#endif
  // form predictor pels
  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];

  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;
  }

  currSlice->mb_pred[pl][joff+0][ioff+0] = (imgpel) ((P_A + P_C + 2*(P_B) + 2) >> 2);
  currSlice->mb_pred[pl][joff+0][ioff+1] =
  currSlice->mb_pred[pl][joff+1][ioff+0] = (imgpel) ((P_B + P_D + 2*(P_C) + 2) >> 2);
  currSlice->mb_pred[pl][joff+0][ioff+2] =
  currSlice->mb_pred[pl][joff+1][ioff+1] =
  currSlice->mb_pred[pl][joff+2][ioff+0] = (imgpel) ((P_C + P_E + 2*(P_D) + 2) >> 2);
  currSlice->mb_pred[pl][joff+0][ioff+3] =
  currSlice->mb_pred[pl][joff+1][ioff+2] =
  currSlice->mb_pred[pl][joff+2][ioff+1] =
  currSlice->mb_pred[pl][joff+3][ioff+0] = (imgpel) ((P_D + P_F + 2*(P_E) + 2) >> 2);
  currSlice->mb_pred[pl][joff+1][ioff+3] =
  currSlice->mb_pred[pl][joff+2][ioff+2] =
  currSlice->mb_pred[pl][joff+3][ioff+1] = (imgpel) ((P_E + P_G + 2*(P_F) + 2) >> 2);
  currSlice->mb_pred[pl][joff+2][ioff+3] =
  currSlice->mb_pred[pl][joff+3][ioff+2] = (imgpel) ((P_F + P_H + 2*(P_G) + 2) >> 2);
  currSlice->mb_pred[pl][joff+3][ioff+3] = (imgpel) ((P_G + 3*(P_H) + 2) >> 2);

  return DECODING_OK;
}

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 4x4 vertical right prediction mode
 *
 * \return
 *    DECODING_OK   decoding of intraprediction mode was sucessfull            \n
 *
 ***********************************************************************
 */
static inline int intra4x4_vert_right_pred(Macroblock *currMB,    //!< current macroblock
                                           ColorPlane pl,         //!< current image plane
                                           int ioff,              //!< pixel offset X within MB
                                           int joff)              //!< pixel offset Y within MB
{
  Slice *currSlice = currMB->p_Slice;
  VideoParameters *p_Vid = currMB->p_Vid;
  

  imgpel PredPel[13];  // array of predictor pels
  imgpel **imgY = (pl) ? p_Vid->dec_picture->imgUV[pl - 1]->img : p_Vid->dec_picture->imgY->img;

  PixelPos pix_a[4];
  PixelPos pix_b, pix_d;

	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +0 , &pix_a[0]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +1 , &pix_a[1]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +2 , &pix_a[2]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +3 , &pix_a[3]);

	p_Vid->getNeighbourPXLumaNB(currMB, ioff    , joff -1 ,  &pix_b);
	p_Vid->getNeighbourLuma(currMB, ioff -1 , joff -1 ,  &pix_d);
#ifdef H264_WARNINGS
	{
		  int i;
		  int block_available_up;
  int block_available_left;
  int block_available_up_left;

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

  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", (int) p_Vid->current_mb_nr);
}
#endif
  // form predictor pels
  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];

  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];

  P_X = imgY[pix_d.pos_y][pix_d.pos_x];

  currSlice->mb_pred[pl][joff+0][ioff+0] =
  currSlice->mb_pred[pl][joff+2][ioff+1] = (imgpel) ((P_X + P_A + 1) >> 1);
  currSlice->mb_pred[pl][joff+0][ioff+1] =
  currSlice->mb_pred[pl][joff+2][ioff+2] = (imgpel) ((P_A + P_B + 1) >> 1);
  currSlice->mb_pred[pl][joff+0][ioff+2] =
  currSlice->mb_pred[pl][joff+2][ioff+3] = (imgpel) ((P_B + P_C + 1) >> 1);
  currSlice->mb_pred[pl][joff+0][ioff+3] = (imgpel) ((P_C + P_D + 1) >> 1);
  currSlice->mb_pred[pl][joff+1][ioff+0] =
  currSlice->mb_pred[pl][joff+3][ioff+1] = (imgpel) ((P_I + 2*P_X + P_A + 2) >> 2);
  currSlice->mb_pred[pl][joff+1][ioff+1] =
  currSlice->mb_pred[pl][joff+3][ioff+2] = (imgpel) ((P_X + 2*P_A + P_B + 2) >> 2);
  currSlice->mb_pred[pl][joff+1][ioff+2] =
  currSlice->mb_pred[pl][joff+3][ioff+3] = (imgpel) ((P_A + 2*P_B + P_C + 2) >> 2);
  currSlice->mb_pred[pl][joff+1][ioff+3] = (imgpel) ((P_B + 2*P_C + P_D + 2) >> 2);
  currSlice->mb_pred[pl][joff+2][ioff+0] = (imgpel) ((P_X + 2*P_I + P_J + 2) >> 2);
  currSlice->mb_pred[pl][joff+3][ioff+0] = (imgpel) ((P_I + 2*P_J + P_K + 2) >> 2);

  return DECODING_OK;
}

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 4x4 vertical left prediction mode
 *
 * \return
 *    DECODING_OK   decoding of intraprediction mode was sucessfull            \n
 *
 ***********************************************************************
 */
static inline int intra4x4_vert_left_pred(Macroblock *currMB,    //!< current macroblock
                                          ColorPlane pl,         //!< current image plane
                                          int ioff,              //!< pixel offset X within MB
                                          int joff)              //!< pixel offset Y within MB
{
  Slice *currSlice = currMB->p_Slice;
  VideoParameters *p_Vid = currMB->p_Vid;
  
  imgpel PredPel[13];  // array of predictor pels  
  imgpel **imgY = (pl) ? p_Vid->dec_picture->imgUV[pl - 1]->img : p_Vid->dec_picture->imgY->img;

  PixelPos pix_b, pix_c;

  int block_available_up;
  int block_available_up_right;

  p_Vid->getNeighbourPXLumaNB(currMB, ioff    , joff -1 ,  &pix_b);
  p_Vid->getNeighbourLuma(currMB, ioff +4 , joff -1 ,  &pix_c);

  pix_c.available = pix_c.available && !((ioff==4) && ((joff==4)||(joff==12)));
  
  if (p_Vid->active_pps->constrained_intra_pred_flag)
  {
    block_available_up       = pix_b.available ? p_Vid->intra_block [pix_b.mb_addr] : 0;
    block_available_up_right = pix_c.available ? p_Vid->intra_block [pix_c.mb_addr] : 0;
  }
  else
  {
    block_available_up       = pix_b.available;
    block_available_up_right = pix_c.available;
  }


  if (!block_available_up)
    printf ("warning: Intra_4x4_Vertical_Left prediction mode not allowed at mb %d\n", (int) p_Vid->current_mb_nr);

  // form predictor pels
  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];

  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;
  }

  currSlice->mb_pred[pl][joff+0][ioff+0] = (imgpel) ((P_A + P_B + 1) >> 1);
  currSlice->mb_pred[pl][joff+0][ioff+1] =
  currSlice->mb_pred[pl][joff+2][ioff+0] = (imgpel) ((P_B + P_C + 1) >> 1);
  currSlice->mb_pred[pl][joff+0][ioff+2] =
  currSlice->mb_pred[pl][joff+2][ioff+1] = (imgpel) ((P_C + P_D + 1) >> 1);
  currSlice->mb_pred[pl][joff+0][ioff+3] =
  currSlice->mb_pred[pl][joff+2][ioff+2] = (imgpel) ((P_D + P_E + 1) >> 1);
  currSlice->mb_pred[pl][joff+2][ioff+3] = (imgpel) ((P_E + P_F + 1) >> 1);
  currSlice->mb_pred[pl][joff+1][ioff+0] = (imgpel) ((P_A + 2*P_B + P_C + 2) >> 2);
  currSlice->mb_pred[pl][joff+1][ioff+1] =
  currSlice->mb_pred[pl][joff+3][ioff+0] = (imgpel) ((P_B + 2*P_C + P_D + 2) >> 2);
  currSlice->mb_pred[pl][joff+1][ioff+2] =
  currSlice->mb_pred[pl][joff+3][ioff+1] = (imgpel) ((P_C + 2*P_D + P_E + 2) >> 2);
  currSlice->mb_pred[pl][joff+1][ioff+3] =
  currSlice->mb_pred[pl][joff+3][ioff+2] = (imgpel) ((P_D + 2*P_E + P_F + 2) >> 2);
  currSlice->mb_pred[pl][joff+3][ioff+3] = (imgpel) ((P_E + 2*P_F + P_G + 2) >> 2);

  return DECODING_OK;
}

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 4x4 horizontal up prediction mode
 *
 * \return
 *    DECODING_OK   decoding of intraprediction mode was sucessfull            \n
 *
 ***********************************************************************
 */
static inline int intra4x4_hor_up_pred(Macroblock *currMB,    //!< current macroblock
                                       ColorPlane pl,         //!< current image plane
                                       int ioff,              //!< pixel offset X within MB
                                       int joff)              //!< pixel offset Y within MB
{
  Slice *currSlice = currMB->p_Slice;
  VideoParameters *p_Vid = currMB->p_Vid;
  
  imgpel PredPel[13];  // array of predictor pels
  imgpel **imgY = (pl) ? p_Vid->dec_picture->imgUV[pl - 1]->img : p_Vid->dec_picture->imgY->img;

  PixelPos pix_a[4];

  p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +0 , &pix_a[0]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +1 , &pix_a[1]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +2 , &pix_a[2]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +3 , &pix_a[3]);

#ifdef H264_WARNINGS
	{
		int i;
		int block_available_left;
  if (p_Vid->active_pps->constrained_intra_pred_flag)
  {
    for (i=0, block_available_left=1; i<4;++i)
      block_available_left  &= pix_a[i].available ? p_Vid->intra_block[pix_a[i].mb_addr]: 0;
  }
  else
  {
    block_available_left     = pix_a[0].available;
  }

  if (!block_available_left)
    printf ("warning: Intra_4x4_Horizontal_Up prediction mode not allowed at mb %d\n",(int) p_Vid->current_mb_nr);
	}
#endif
  // form predictor pels
  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];

  currSlice->mb_pred[pl][joff+0][ioff+0] = (imgpel) ((P_I + P_J + 1) >> 1);
  currSlice->mb_pred[pl][joff+0][ioff+1] = (imgpel) ((P_I + 2*P_J + P_K + 2) >> 2);
  currSlice->mb_pred[pl][joff+0][ioff+2] =
  currSlice->mb_pred[pl][joff+1][ioff+0] = (imgpel) ((P_J + P_K + 1) >> 1);
  currSlice->mb_pred[pl][joff+0][ioff+3] =
  currSlice->mb_pred[pl][joff+1][ioff+1] = (imgpel) ((P_J + 2*P_K + P_L + 2) >> 2);
  currSlice->mb_pred[pl][joff+1][ioff+2] =
  currSlice->mb_pred[pl][joff+2][ioff+0] = (imgpel) ((P_K + P_L + 1) >> 1);
  currSlice->mb_pred[pl][joff+1][ioff+3] =
  currSlice->mb_pred[pl][joff+2][ioff+1] = (imgpel) ((P_K + 2*P_L + P_L + 2) >> 2);
  currSlice->mb_pred[pl][joff+2][ioff+3] =
  currSlice->mb_pred[pl][joff+3][ioff+1] =
  currSlice->mb_pred[pl][joff+3][ioff+0] =
  currSlice->mb_pred[pl][joff+2][ioff+2] =
  currSlice->mb_pred[pl][joff+3][ioff+2] =
  currSlice->mb_pred[pl][joff+3][ioff+3] = (imgpel) P_L;

  return DECODING_OK;
}

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 4x4 horizontal down prediction mode
 *
 * \return
 *    DECODING_OK   decoding of intraprediction mode was sucessfull            \n
 *
 ***********************************************************************
 */
static inline int intra4x4_hor_down_pred(Macroblock *currMB,    //!< current macroblock
                                         ColorPlane pl,         //!< current image plane
                                         int ioff,              //!< pixel offset X within MB
                                         int joff)              //!< pixel offset Y within MB
{
  Slice *currSlice = currMB->p_Slice;
  VideoParameters *p_Vid = currMB->p_Vid;
  
  int i;
  imgpel PredPel[13];  // array of predictor pels
  imgpel **imgY = (pl) ? p_Vid->dec_picture->imgUV[pl - 1]->img : p_Vid->dec_picture->imgY->img;

  PixelPos pix_a[4];
  PixelPos pix_b, pix_d;

  int block_available_up;
  int block_available_left;
  int block_available_up_left;

	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +0 , &pix_a[0]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +1 , &pix_a[1]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +2 , &pix_a[2]);
	p_Vid->getNeighbourXPLumaNB(currMB, ioff -1 , joff +3 , &pix_a[3]);

  p_Vid->getNeighbourPXLumaNB(currMB, ioff    , joff -1 ,  &pix_b);
  p_Vid->getNeighbourLuma(currMB, ioff -1 , joff -1 ,  &pix_d);

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

  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", (int) p_Vid->current_mb_nr);

  // form predictor pels
  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];

  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];

  P_X = imgY[pix_d.pos_y][pix_d.pos_x];

  currSlice->mb_pred[pl][joff+0][ioff+0] =
  currSlice->mb_pred[pl][joff+1][ioff+2] = (imgpel) ((P_X + P_I + 1) >> 1);
  currSlice->mb_pred[pl][joff+0][ioff+1] =
  currSlice->mb_pred[pl][joff+1][ioff+3] = (imgpel) ((P_I + 2*P_X + P_A + 2) >> 2);
  currSlice->mb_pred[pl][joff+0][ioff+2] = (imgpel) ((P_X + 2*P_A + P_B + 2) >> 2);
  currSlice->mb_pred[pl][joff+0][ioff+3] = (imgpel) ((P_A + 2*P_B + P_C + 2) >> 2);
  currSlice->mb_pred[pl][joff+1][ioff+0] =
  currSlice->mb_pred[pl][joff+2][ioff+2] = (imgpel) ((P_I + P_J + 1) >> 1);
  currSlice->mb_pred[pl][joff+1][ioff+1] =
  currSlice->mb_pred[pl][joff+2][ioff+3] = (imgpel) ((P_X + 2*P_I + P_J + 2) >> 2);
  currSlice->mb_pred[pl][joff+2][ioff+0] =
  currSlice->mb_pred[pl][joff+3][ioff+2] = (imgpel) ((P_J + P_K + 1) >> 1);
  currSlice->mb_pred[pl][joff+2][ioff+1] =
  currSlice->mb_pred[pl][joff+3][ioff+3] = (imgpel) ((P_I + 2*P_J + P_K + 2) >> 2);
  currSlice->mb_pred[pl][joff+3][ioff+0] = (imgpel) ((P_K + P_L + 1) >> 1);
  currSlice->mb_pred[pl][joff+3][ioff+1] = (imgpel) ((P_J + 2*P_K + P_L + 2) >> 2);

  return DECODING_OK;
}


/*!
 ***********************************************************************
 * \brief
 *    makes and returns 4x4 intra prediction blocks 
 *
 * \return
 *    DECODING_OK   decoding of intraprediction mode was sucessfull            \n
 *    SEARCH_SYNC   search next sync element as errors while decoding occured
 ***********************************************************************
 */
int intrapred(Macroblock *currMB,    //!< current macroblock
              ColorPlane pl,         //!< current image plane
              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
{
  VideoParameters *p_Vid = currMB->p_Vid;
  byte predmode = p_Vid->ipredmode[img_block_y][img_block_x];
  currMB->ipmode_DPCM = predmode; //For residual DPCM

  switch (predmode)
  {
  case DC_PRED:
    return (intra4x4_dc_pred(currMB, pl, ioff, joff));
    break;
  case VERT_PRED:
    return (intra4x4_vert_pred(currMB, pl, ioff, joff));
    break;
  case HOR_PRED:
    return (intra4x4_hor_pred(currMB, pl, ioff, joff));
    break;
  case DIAG_DOWN_RIGHT_PRED:
    return (intra4x4_diag_down_right_pred(currMB, pl, ioff, joff));
    break;
  case DIAG_DOWN_LEFT_PRED:
    return (intra4x4_diag_down_left_pred(currMB, pl, ioff, joff));
    break;
  case VERT_RIGHT_PRED:
    return (intra4x4_vert_right_pred(currMB, pl, ioff, joff));
    break;
  case VERT_LEFT_PRED:
    return (intra4x4_vert_left_pred(currMB, pl, ioff, joff));
    break;
  case HOR_UP_PRED:
    return (intra4x4_hor_up_pred(currMB, pl, ioff, joff));
    break;
  case HOR_DOWN_PRED:  
    return (intra4x4_hor_down_pred(currMB, pl, ioff, joff));
  default:
    printf("Error: illegal intra_4x4 prediction mode: %d\n", (int) predmode);
    return SEARCH_SYNC;
    break;
  }
}