📄 intra8x8_pred.c
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/*!
*************************************************************************************
* \file intra8x8_pred.c
*
* \brief
* Functions for intra 8x8 prediction
*
* \author
* Main contributors (see contributors.h for copyright,
* address and affiliation details)
* - Yuri Vatis
* - Jan Muenster
* - Alexis Michael Tourapis <alexismt@ieee.org>
*
*************************************************************************************
*/
#include "global.h"
#include "intra8x8_pred.h"
#include "mb_access.h"
#include "image.h"
// Notation for comments regarding prediction and predictors.
// The pels of the 8x8 block are labeled a..p. The predictor pels above
// are labeled A..H, from the left I..P, and from above left X, as follows:
//
// Z A B C D E F G H I J K L M N O P
// Q a1 b1 c1 d1 e1 f1 g1 h1
// R a2 b2 c2 d2 e2 f2 g2 h2
// S a3 b3 c3 d3 e3 f3 g3 h3
// T a4 b4 c4 d4 e4 f4 g4 h4
// U a5 b5 c5 d5 e5 f5 g5 h5
// V a6 b6 c6 d6 e6 f6 g6 h6
// W a7 b7 c7 d7 e7 f7 g7 h7
// X a8 b8 c8 d8 e8 f8 g8 h8
// Predictor array index definitions
#define P_Z (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])
#define P_M (PredPel[13])
#define P_N (PredPel[14])
#define P_O (PredPel[15])
#define P_P (PredPel[16])
#define P_Q (PredPel[17])
#define P_R (PredPel[18])
#define P_S (PredPel[19])
#define P_T (PredPel[20])
#define P_U (PredPel[21])
#define P_V (PredPel[22])
#define P_W (PredPel[23])
#define P_X (PredPel[24])
/*!
*************************************************************************************
* \brief
* Prefiltering for Intra8x8 prediction
*************************************************************************************
*/
static inline void LowPassForIntra8x8Pred(imgpel *PredPel, int block_up_left, int block_up, int block_left)
{
int i;
static imgpel LoopArray[25];
memcpy(&LoopArray[0], &PredPel[0], 25 * sizeof(imgpel));
if(block_up_left)
{
if(block_up && block_left)
{
LoopArray[0] = (imgpel) ((P_Q + (P_Z<<1) + P_A + 2)>>2);
}
else
{
if(block_up)
LoopArray[0] = (imgpel) ((P_Z + (P_Z<<1) + P_A + 2)>>2);
else if (block_left)
LoopArray[0] = (imgpel) ((P_Z + (P_Z<<1) + P_Q + 2)>>2);
}
}
if(block_up)
{
if(block_up_left)
{
LoopArray[1] = (imgpel) ((PredPel[0] + (PredPel[1]<<1) + PredPel[2] + 2)>>2);
}
else
LoopArray[1] = (imgpel) ((PredPel[1] + (PredPel[1]<<1) + PredPel[2] + 2)>>2);
for(i = 2; i <16; i++)
{
LoopArray[i] = (imgpel) ((PredPel[i-1] + (PredPel[i]<<1) + PredPel[i+1] + 2)>>2);
}
LoopArray[16] = (imgpel) ((P_P + (P_P<<1) + P_O + 2)>>2);
}
if(block_left)
{
if(block_up_left)
LoopArray[17] = (imgpel) ((P_Z + (P_Q<<1) + P_R + 2)>>2);
else
LoopArray[17] = (imgpel) ((P_Q + (P_Q<<1) + P_R + 2)>>2);
for(i = 18; i <24; i++)
{
LoopArray[i] = (imgpel) ((PredPel[i-1] + (PredPel[i]<<1) + PredPel[i+1] + 2)>>2);
}
LoopArray[24] = (imgpel) ((P_W + (P_X<<1) + P_X + 2) >> 2);
}
memcpy(&PredPel[0], &LoopArray[0], 25 * sizeof(imgpel));
}
/*!
*************************************************************************************
* \brief
* Prefiltering for Intra8x8 prediction (Horizontal)
*************************************************************************************
*/
static inline void LowPassForIntra8x8PredHor(imgpel *PredPel, int block_up_left, int block_up, int block_left)
{
int i;
static imgpel LoopArray[25];
memcpy(&LoopArray[0], &PredPel[0], 25 * sizeof(imgpel));
if(block_up_left)
{
if(block_up && block_left)
{
LoopArray[0] = (imgpel) ((P_Q + (P_Z<<1) + P_A + 2)>>2);
}
else
{
if(block_up)
LoopArray[0] = (imgpel) ((P_Z + (P_Z<<1) + P_A + 2)>>2);
else if (block_left)
LoopArray[0] = (imgpel) ((P_Z + (P_Z<<1) + P_Q + 2)>>2);
}
}
if(block_up)
{
if(block_up_left)
{
LoopArray[1] = (imgpel) ((PredPel[0] + (PredPel[1]<<1) + PredPel[2] + 2)>>2);
}
else
LoopArray[1] = (imgpel) ((PredPel[1] + (PredPel[1]<<1) + PredPel[2] + 2)>>2);
for(i = 2; i <16; i++)
{
LoopArray[i] = (imgpel) ((PredPel[i-1] + (PredPel[i]<<1) + PredPel[i+1] + 2)>>2);
}
LoopArray[16] = (imgpel) ((P_P + (P_P<<1) + P_O + 2)>>2);
}
memcpy(&PredPel[0], &LoopArray[0], 17 * sizeof(imgpel));
}
/*!
*************************************************************************************
* \brief
* Prefiltering for Intra8x8 prediction (Vertical)
*************************************************************************************
*/
static inline void LowPassForIntra8x8PredVer(imgpel *PredPel, int block_up_left, int block_up, int block_left)
{
// These functions need some cleanup and can be further optimized.
// For convenience, let us copy all data for now. It is obvious that the filtering makes things a bit more "complex"
int i;
static imgpel LoopArray[25];
memcpy(&LoopArray[0], &PredPel[0], 25 * sizeof(imgpel));
if(block_up_left)
{
if(block_up && block_left)
{
LoopArray[0] = (imgpel) ((P_Q + (P_Z<<1) + P_A + 2)>>2);
}
else
{
if(block_up)
LoopArray[0] = (imgpel) ((P_Z + (P_Z<<1) + P_A + 2)>>2);
else if (block_left)
LoopArray[0] = (imgpel) ((P_Z + (P_Z<<1) + P_Q + 2)>>2);
}
}
if(block_left)
{
if(block_up_left)
LoopArray[17] = (imgpel) ((P_Z + (P_Q<<1) + P_R + 2)>>2);
else
LoopArray[17] = (imgpel) ((P_Q + (P_Q<<1) + P_R + 2)>>2);
for(i = 18; i <24; i++)
{
LoopArray[i] = (imgpel) ((PredPel[i-1] + (PredPel[i]<<1) + PredPel[i+1] + 2)>>2);
}
LoopArray[24] = (imgpel) ((P_W + (P_X<<1) + P_X + 2) >> 2);
}
memcpy(&PredPel[0], &LoopArray[0], 25 * sizeof(imgpel));
}
/*!
***********************************************************************
* \brief
* makes and returns 8x8 DC prediction mode
*
* \return
* DECODING_OK decoding of intraprediction mode was sucessfull \n
*
***********************************************************************
*/
static inline int intra8x8_dc_pred(ImageParameters *img, //!< image parameters
Macroblock *currMB, //!< current macroblock
ColorPlane pl, //!< current image plane
int ioff, //!< pixel offset X within MB
int joff) //!< pixel offset Y within MB
{
int i,j;
int s0 = 0;
imgpel PredPel[25]; // array of predictor pels
imgpel **imgY = (pl) ? dec_picture->imgUV[pl - 1] : dec_picture->imgY; // For MB level frame/field coding tools -- set default to imgY
PixelPos pix_a[8];
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;
imgpel *pred_pels, **mpr = img->mb_pred[pl];
int *mb_size = img->mb_size[IS_LUMA];
for (i=0;i<8;i++)
{
getNeighbour(currMB, ioff - 1, joff + i, mb_size, &pix_a[i]);
}
getNeighbour(currMB, ioff , joff - 1, mb_size, &pix_b);
getNeighbour(currMB, ioff + 8, joff - 1, mb_size, &pix_c);
getNeighbour(currMB, ioff - 1, joff - 1, mb_size, &pix_d);
pix_c.available = pix_c.available &&!(ioff == 8 && joff == 8);
if (active_pps->constrained_intra_pred_flag)
{
for (i=0, block_available_left=1; i<8;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)
{
pred_pels = &imgY[pix_b.pos_y][pix_b.pos_x];
P_A = pred_pels[0];
P_B = pred_pels[1];
P_C = pred_pels[2];
P_D = pred_pels[3];
P_E = pred_pels[4];
P_F = pred_pels[5];
P_G = pred_pels[6];
P_H = pred_pels[7];
}
else
{
P_A = P_B = P_C = P_D = P_E = P_F = P_G = P_H = (imgpel) img->dc_pred_value_comp[pl];
}
if (block_available_up_right)
{
pred_pels = &imgY[pix_c.pos_y][pix_c.pos_x];
P_I = pred_pels[0];
P_J = pred_pels[1];
P_K = pred_pels[2];
P_L = pred_pels[3];
P_M = pred_pels[4];
P_N = pred_pels[5];
P_O = pred_pels[6];
P_P = pred_pels[7];
}
else
{
P_I = P_J = P_K = P_L = P_M = P_N = P_O = P_P = P_H;
}
if (block_available_left)
{
P_Q = imgY[pix_a[0].pos_y][pix_a[0].pos_x];
P_R = imgY[pix_a[1].pos_y][pix_a[1].pos_x];
P_S = imgY[pix_a[2].pos_y][pix_a[2].pos_x];
P_T = imgY[pix_a[3].pos_y][pix_a[3].pos_x];
P_U = imgY[pix_a[4].pos_y][pix_a[4].pos_x];
P_V = imgY[pix_a[5].pos_y][pix_a[5].pos_x];
P_W = imgY[pix_a[6].pos_y][pix_a[6].pos_x];
P_X = imgY[pix_a[7].pos_y][pix_a[7].pos_x];
}
else
{
P_Q = P_R = P_S = P_T = P_U = P_V = P_W = P_X = (imgpel) img->dc_pred_value_comp[pl];
}
if (block_available_up_left)
{
P_Z = imgY[pix_d.pos_y][pix_d.pos_x];
}
else
{
P_Z = (imgpel) img->dc_pred_value_comp[pl];
}
LowPassForIntra8x8Pred(&(P_Z), block_available_up_left, block_available_up, block_available_left);
if (block_available_up && block_available_left)
{
// no edge
s0 = (P_A + P_B + P_C + P_D + P_E + P_F + P_G + P_H + P_Q + P_R + P_S + P_T + P_U + P_V + P_W + P_X + 8) >> 4;
}
else if (!block_available_up && block_available_left)
{
// upper edge
s0 = (P_Q + P_R + P_S + P_T + P_U + P_V + P_W + P_X + 4) >> 3;
}
else if (block_available_up && !block_available_left)
{
// left edge
s0 = (P_A + P_B + P_C + P_D + P_E + P_F + P_G + P_H + 4) >> 3;
}
else //if (!block_available_up && !block_available_left)
{
// top left corner, nothing to predict from
s0 = img->dc_pred_value_comp[pl];
}
for(j = joff; j < joff + BLOCK_SIZE_8x8; j++)
for(i = ioff; i < ioff + BLOCK_SIZE_8x8; i++)
mpr[j][i] = (imgpel) s0;
return DECODING_OK;
}
/*!
***********************************************************************
* \brief
* makes and returns 8x8 vertical prediction mode
*
* \return
* DECODING_OK decoding of intraprediction mode was sucessfull \n
*
***********************************************************************
*/
static inline int intra8x8_vert_pred(ImageParameters *img, //!< image parameters
Macroblock *currMB, //!< current macroblock
ColorPlane pl, //!< current image plane
int ioff, //!< pixel offset X within MB
int joff) //!< pixel offset Y within MB
{
int i;
imgpel PredPel[25]; // array of predictor pels
imgpel **imgY = (pl) ? dec_picture->imgUV[pl - 1] : dec_picture->imgY; // For MB level frame/field coding tools -- set default to imgY
PixelPos pix_a[8];
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;
imgpel *pred_pels, **mpr = img->mb_pred[pl];
int *mb_size = img->mb_size[IS_LUMA];
for (i=0;i<8;i++)
{
getNeighbour(currMB, ioff - 1, joff + i, mb_size, &pix_a[i]);
}
getNeighbour(currMB, ioff , joff - 1, mb_size, &pix_b);
getNeighbour(currMB, ioff + 8, joff - 1, mb_size, &pix_c);
getNeighbour(currMB, ioff - 1, joff - 1, mb_size, &pix_d);
pix_c.available = pix_c.available &&!(ioff == 8 && joff == 8);
if (active_pps->constrained_intra_pred_flag)
{
for (i=0, block_available_left=1; i<8;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;
}
if (!block_available_up)
printf ("warning: Intra_8x8_Vertical prediction mode not allowed at mb %d\n", (int) img->current_mb_nr);
// form predictor pels
if (block_available_up)
{
pred_pels = &imgY[pix_b.pos_y][pix_b.pos_x];
P_A = *(pred_pels ++);
P_B = *(pred_pels ++);
P_C = *(pred_pels ++);
P_D = *(pred_pels ++);
P_E = *(pred_pels ++);
P_F = *(pred_pels ++);
P_G = *(pred_pels ++);
P_H = *pred_pels;
}
else
{
P_A = P_B = P_C = P_D = P_E = P_F = P_G = P_H = (imgpel) img->dc_pred_value_comp[pl];
}
if (block_available_up_right)
{
pred_pels = &imgY[pix_c.pos_y][pix_c.pos_x];
P_I = *(pred_pels ++);
P_J = *(pred_pels ++);
P_K = *(pred_pels ++);
P_L = *(pred_pels ++);
P_M = *(pred_pels ++);
P_N = *(pred_pels ++);
P_O = *(pred_pels ++);
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