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/*
* Simple IDCT
*
* Copyright (c) 2001 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* simpleidct in C.
*/
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "dsputil.h"
#include "mathops.h"
#include "simple_idct.h"
#define BIT_DEPTH 8
#include "simple_idct_template.c"
#undef BIT_DEPTH
#define BIT_DEPTH 10
#include "simple_idct_template.c"
#undef BIT_DEPTH
/* 2x4x8 idct */
#define CN_SHIFT 12
#define C_FIX(x) ((int)((x) * (1 << CN_SHIFT) + 0.5))
#define C1 C_FIX(0.6532814824)
#define C2 C_FIX(0.2705980501)
/* row idct is multiple by 16 * sqrt(2.0), col idct4 is normalized,
and the butterfly must be multiplied by 0.5 * sqrt(2.0) */
#define C_SHIFT (4+1+12)
static inline void idct4col_put(uint8_t *dest, int line_size, const DCTELEM *col)
{
int c0, c1, c2, c3, a0, a1, a2, a3;
a0 = col[8*0];
a1 = col[8*2];
a2 = col[8*4];
a3 = col[8*6];
c0 = ((a0 + a2) << (CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
c2 = ((a0 - a2) << (CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
c1 = a1 * C1 + a3 * C2;
c3 = a1 * C2 - a3 * C1;
dest[0] = av_clip_uint8((c0 + c1) >> C_SHIFT);
dest += line_size;
dest[0] = av_clip_uint8((c2 + c3) >> C_SHIFT);
dest += line_size;
dest[0] = av_clip_uint8((c2 - c3) >> C_SHIFT);
dest += line_size;
dest[0] = av_clip_uint8((c0 - c1) >> C_SHIFT);
}
#define BF(k) \
{\
int a0, a1;\
a0 = ptr[k];\
a1 = ptr[8 + k];\
ptr[k] = a0 + a1;\
ptr[8 + k] = a0 - a1;\
}
/* only used by DV codec. The input must be interlaced. 128 is added
to the pixels before clamping to avoid systematic error
(1024*sqrt(2)) offset would be needed otherwise. */
/* XXX: I think a 1.0/sqrt(2) normalization should be needed to
compensate the extra butterfly stage - I don't have the full DV
specification */
void ff_simple_idct248_put(uint8_t *dest, int line_size, DCTELEM *block)
{
int i;
DCTELEM *ptr;
/* butterfly */
ptr = block;
for(i=0;i<4;i++) {
BF(0);
BF(1);
BF(2);
BF(3);
BF(4);
BF(5);
BF(6);
BF(7);
ptr += 2 * 8;
}
/* IDCT8 on each line */
for(i=0; i<8; i++) {
idctRowCondDC_8(block + i*8, 0);
}
/* IDCT4 and store */
for(i=0;i<8;i++) {
idct4col_put(dest + i, 2 * line_size, block + i);
idct4col_put(dest + line_size + i, 2 * line_size, block + 8 + i);
}
}
/* 8x4 & 4x8 WMV2 IDCT */
#undef CN_SHIFT
#undef C_SHIFT
#undef C_FIX
#undef C1
#undef C2
#define CN_SHIFT 12
#define C_FIX(x) ((int)((x) * 1.414213562 * (1 << CN_SHIFT) + 0.5))
#define C1 C_FIX(0.6532814824)
#define C2 C_FIX(0.2705980501)
#define C3 C_FIX(0.5)
#define C_SHIFT (4+1+12)
static inline void idct4col_add(uint8_t *dest, int line_size, const DCTELEM *col)
{
int c0, c1, c2, c3, a0, a1, a2, a3;
a0 = col[8*0];
a1 = col[8*1];
a2 = col[8*2];
a3 = col[8*3];
c0 = (a0 + a2)*C3 + (1 << (C_SHIFT - 1));
c2 = (a0 - a2)*C3 + (1 << (C_SHIFT - 1));
c1 = a1 * C1 + a3 * C2;
c3 = a1 * C2 - a3 * C1;
dest[0] = av_clip_uint8(dest[0] + ((c0 + c1) >> C_SHIFT));
dest += line_size;
dest[0] = av_clip_uint8(dest[0] + ((c2 + c3) >> C_SHIFT));
dest += line_size;
dest[0] = av_clip_uint8(dest[0] + ((c2 - c3) >> C_SHIFT));
dest += line_size;
dest[0] = av_clip_uint8(dest[0] + ((c0 - c1) >> C_SHIFT));
}
#define RN_SHIFT 15
#define R_FIX(x) ((int)((x) * 1.414213562 * (1 << RN_SHIFT) + 0.5))
#define R1 R_FIX(0.6532814824)
#define R2 R_FIX(0.2705980501)
#define R3 R_FIX(0.5)
#define R_SHIFT 11
static inline void idct4row(DCTELEM *row)
{
int c0, c1, c2, c3, a0, a1, a2, a3;
a0 = row[0];
a1 = row[1];
a2 = row[2];
a3 = row[3];
c0 = (a0 + a2)*R3 + (1 << (R_SHIFT - 1));
c2 = (a0 - a2)*R3 + (1 << (R_SHIFT - 1));
c1 = a1 * R1 + a3 * R2;
c3 = a1 * R2 - a3 * R1;
row[0]= (c0 + c1) >> R_SHIFT;
row[1]= (c2 + c3) >> R_SHIFT;
row[2]= (c2 - c3) >> R_SHIFT;
row[3]= (c0 - c1) >> R_SHIFT;
}
void ff_simple_idct84_add(uint8_t *dest, int line_size, DCTELEM *block)
{
int i;
/* IDCT8 on each line */
for(i=0; i<4; i++) {
idctRowCondDC_8(block + i*8, 0);
}
/* IDCT4 and store */
for(i=0;i<8;i++) {
idct4col_add(dest + i, line_size, block + i);
}
}
void ff_simple_idct48_add(uint8_t *dest, int line_size, DCTELEM *block)
{
int i;
/* IDCT4 on each line */
for(i=0; i<8; i++) {
idct4row(block + i*8);
}
/* IDCT8 and store */
for(i=0; i<4; i++){
idctSparseColAdd_8(dest + i, line_size, block + i);
}
}
void ff_simple_idct44_add(uint8_t *dest, int line_size, DCTELEM *block)
{
int i;
/* IDCT4 on each line */
for(i=0; i<4; i++) {
idct4row(block + i*8);
}
/* IDCT4 and store */
for(i=0; i<4; i++){
idct4col_add(dest + i, line_size, block + i);
}
}
void ff_prores_idct(DCTELEM *block, const int16_t *qmat)
{
int i;
for (i = 0; i < 64; i++)
block[i] *= qmat[i];
for (i = 0; i < 8; i++)
idctRowCondDC_10(block + i*8, 2);
for (i = 0; i < 8; i++)
idctSparseCol_10(block + i);
}
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