ffmpeg/libavcodec/vp3dsp.c
Mike Melanson 116824d0aa reorganize and simplify the VP3 IDCT stuff
Originally committed as revision 3071 to svn://svn.ffmpeg.org/ffmpeg/trunk
2004-04-26 00:20:29 +00:00

259 lines
6.7 KiB
C

/*
* Copyright (C) 2004 the ffmpeg project
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* @file vp3dsp.c
* Standard C DSP-oriented functions cribbed from the original VP3
* source code.
*/
#include "common.h"
#include "avcodec.h"
#include "vp3data.h"
#define IdctAdjustBeforeShift 8
#define xC1S7 64277
#define xC2S6 60547
#define xC3S5 54491
#define xC4S4 46341
#define xC5S3 36410
#define xC6S2 25080
#define xC7S1 12785
void vp3_dsp_init_c(void)
{
/* nop */
}
void vp3_idct_c(int16_t *input_data, int16_t *dequant_matrix,
int coeff_count, int16_t *output_data)
{
int32_t dequantized_data[64];
int32_t *ip = dequantized_data;
int16_t *op = output_data;
int32_t A_, B_, C_, D_, _Ad, _Bd, _Cd, _Dd, E_, F_, G_, H_;
int32_t _Ed, _Gd, _Add, _Bdd, _Fd, _Hd;
int32_t t1, t2;
int i, j;
/* de-zigzag and dequantize */
for (i = 0; i < coeff_count; i++) {
j = dezigzag_index[i];
dequantized_data[j] = dequant_matrix[i] * input_data[i];
}
/* Inverse DCT on the rows now */
for (i = 0; i < 8; i++) {
/* Check for non-zero values */
if ( ip[0] | ip[1] | ip[2] | ip[3] | ip[4] | ip[5] | ip[6] | ip[7] ) {
t1 = (int32_t)(xC1S7 * ip[1]);
t2 = (int32_t)(xC7S1 * ip[7]);
t1 >>= 16;
t2 >>= 16;
A_ = t1 + t2;
t1 = (int32_t)(xC7S1 * ip[1]);
t2 = (int32_t)(xC1S7 * ip[7]);
t1 >>= 16;
t2 >>= 16;
B_ = t1 - t2;
t1 = (int32_t)(xC3S5 * ip[3]);
t2 = (int32_t)(xC5S3 * ip[5]);
t1 >>= 16;
t2 >>= 16;
C_ = t1 + t2;
t1 = (int32_t)(xC3S5 * ip[5]);
t2 = (int32_t)(xC5S3 * ip[3]);
t1 >>= 16;
t2 >>= 16;
D_ = t1 - t2;
t1 = (int32_t)(xC4S4 * (A_ - C_));
t1 >>= 16;
_Ad = t1;
t1 = (int32_t)(xC4S4 * (B_ - D_));
t1 >>= 16;
_Bd = t1;
_Cd = A_ + C_;
_Dd = B_ + D_;
t1 = (int32_t)(xC4S4 * (ip[0] + ip[4]));
t1 >>= 16;
E_ = t1;
t1 = (int32_t)(xC4S4 * (ip[0] - ip[4]));
t1 >>= 16;
F_ = t1;
t1 = (int32_t)(xC2S6 * ip[2]);
t2 = (int32_t)(xC6S2 * ip[6]);
t1 >>= 16;
t2 >>= 16;
G_ = t1 + t2;
t1 = (int32_t)(xC6S2 * ip[2]);
t2 = (int32_t)(xC2S6 * ip[6]);
t1 >>= 16;
t2 >>= 16;
H_ = t1 - t2;
_Ed = E_ - G_;
_Gd = E_ + G_;
_Add = F_ + _Ad;
_Bdd = _Bd - H_;
_Fd = F_ - _Ad;
_Hd = _Bd + H_;
/* Final sequence of operations over-write original inputs. */
ip[0] = (int16_t)((_Gd + _Cd ) >> 0);
ip[7] = (int16_t)((_Gd - _Cd ) >> 0);
ip[1] = (int16_t)((_Add + _Hd ) >> 0);
ip[2] = (int16_t)((_Add - _Hd ) >> 0);
ip[3] = (int16_t)((_Ed + _Dd ) >> 0);
ip[4] = (int16_t)((_Ed - _Dd ) >> 0);
ip[5] = (int16_t)((_Fd + _Bdd ) >> 0);
ip[6] = (int16_t)((_Fd - _Bdd ) >> 0);
}
ip += 8; /* next row */
}
ip = dequantized_data;
for ( i = 0; i < 8; i++) {
/* Check for non-zero values (bitwise or faster than ||) */
if ( ip[0 * 8] | ip[1 * 8] | ip[2 * 8] | ip[3 * 8] |
ip[4 * 8] | ip[5 * 8] | ip[6 * 8] | ip[7 * 8] ) {
t1 = (int32_t)(xC1S7 * ip[1*8]);
t2 = (int32_t)(xC7S1 * ip[7*8]);
t1 >>= 16;
t2 >>= 16;
A_ = t1 + t2;
t1 = (int32_t)(xC7S1 * ip[1*8]);
t2 = (int32_t)(xC1S7 * ip[7*8]);
t1 >>= 16;
t2 >>= 16;
B_ = t1 - t2;
t1 = (int32_t)(xC3S5 * ip[3*8]);
t2 = (int32_t)(xC5S3 * ip[5*8]);
t1 >>= 16;
t2 >>= 16;
C_ = t1 + t2;
t1 = (int32_t)(xC3S5 * ip[5*8]);
t2 = (int32_t)(xC5S3 * ip[3*8]);
t1 >>= 16;
t2 >>= 16;
D_ = t1 - t2;
t1 = (int32_t)(xC4S4 * (A_ - C_));
t1 >>= 16;
_Ad = t1;
t1 = (int32_t)(xC4S4 * (B_ - D_));
t1 >>= 16;
_Bd = t1;
_Cd = A_ + C_;
_Dd = B_ + D_;
t1 = (int32_t)(xC4S4 * (ip[0*8] + ip[4*8]));
t1 >>= 16;
E_ = t1;
t1 = (int32_t)(xC4S4 * (ip[0*8] - ip[4*8]));
t1 >>= 16;
F_ = t1;
t1 = (int32_t)(xC2S6 * ip[2*8]);
t2 = (int32_t)(xC6S2 * ip[6*8]);
t1 >>= 16;
t2 >>= 16;
G_ = t1 + t2;
t1 = (int32_t)(xC6S2 * ip[2*8]);
t2 = (int32_t)(xC2S6 * ip[6*8]);
t1 >>= 16;
t2 >>= 16;
H_ = t1 - t2;
_Ed = E_ - G_;
_Gd = E_ + G_;
_Add = F_ + _Ad;
_Bdd = _Bd - H_;
_Fd = F_ - _Ad;
_Hd = _Bd + H_;
_Gd += IdctAdjustBeforeShift;
_Add += IdctAdjustBeforeShift;
_Ed += IdctAdjustBeforeShift;
_Fd += IdctAdjustBeforeShift;
/* Final sequence of operations over-write original inputs. */
op[0*8] = (int16_t)((_Gd + _Cd ) >> 4);
op[7*8] = (int16_t)((_Gd - _Cd ) >> 4);
op[1*8] = (int16_t)((_Add + _Hd ) >> 4);
op[2*8] = (int16_t)((_Add - _Hd ) >> 4);
op[3*8] = (int16_t)((_Ed + _Dd ) >> 4);
op[4*8] = (int16_t)((_Ed - _Dd ) >> 4);
op[5*8] = (int16_t)((_Fd + _Bdd ) >> 4);
op[6*8] = (int16_t)((_Fd - _Bdd ) >> 4);
} else {
op[0*8] = 0;
op[7*8] = 0;
op[1*8] = 0;
op[2*8] = 0;
op[3*8] = 0;
op[4*8] = 0;
op[5*8] = 0;
op[6*8] = 0;
}
ip++; /* next column */
op++;
}
}