/*
* Copyright (C) 2016 foo86
*
* 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
*/
#include "libavutil/common.h"
#include "dcadct.h"
#include "dcamath.h"
static void sum_a(const int *input, int *output, int len)
{
int i;
for (i = 0; i < len; i++)
output[i] = input[2 * i] + input[2 * i + 1];
}
static void sum_b(const int *input, int *output, int len)
{
int i;
output[0] = input[0];
for (i = 1; i < len; i++)
output[i] = input[2 * i] + input[2 * i - 1];
}
static void sum_c(const int *input, int *output, int len)
{
int i;
for (i = 0; i < len; i++)
output[i] = input[2 * i];
}
static void sum_d(const int *input, int *output, int len)
{
int i;
output[0] = input[1];
for (i = 1; i < len; i++)
output[i] = input[2 * i - 1] + input[2 * i + 1];
}
static void dct_a(const int *input, int *output)
{
static const int cos_mod[8][8] = {
{ 8348215, 8027397, 7398092, 6484482, 5321677, 3954362, 2435084, 822227 },
{ 8027397, 5321677, 822227, -3954362, -7398092, -8348215, -6484482, -2435084 },
{ 7398092, 822227, -6484482, -8027397, -2435084, 5321677, 8348215, 3954362 },
{ 6484482, -3954362, -8027397, 822227, 8348215, 2435084, -7398092, -5321677 },
{ 5321677, -7398092, -2435084, 8348215, -822227, -8027397, 3954362, 6484482 },
{ 3954362, -8348215, 5321677, 2435084, -8027397, 6484482, 822227, -7398092 },
{ 2435084, -6484482, 8348215, -7398092, 3954362, 822227, -5321677, 8027397 },
{ 822227, -2435084, 3954362, -5321677, 6484482, -7398092, 8027397, -8348215 }
};
int i, j;
for (i = 0; i < 8; i++) {
int64_t res = 0;
for (j = 0; j < 8; j++)
res += (int64_t)cos_mod[i][j] * input[j];
output[i] = norm23(res);
}
}
static void dct_b(const int *input, int *output)
{
static const int cos_mod[8][7] = {
{ 8227423, 7750063, 6974873, 5931642, 4660461, 3210181, 1636536 },
{ 6974873, 3210181, -1636536, -5931642, -8227423, -7750063, -4660461 },
{ 4660461, -3210181, -8227423, -5931642, 1636536, 7750063, 6974873 },
{ 1636536, -7750063, -4660461, 5931642, 6974873, -3210181, -8227423 },
{ -1636536, -7750063, 4660461, 5931642, -6974873, -3210181, 8227423 },
{ -4660461, -3210181, 8227423, -5931642, -1636536, 7750063, -6974873 },
{ -6974873, 3210181, 1636536, -5931642, 8227423, -7750063, 4660461 },
{ -8227423, 7750063, -6974873, 5931642, -4660461, 3210181, -1636536 }
};
int i, j;
for (i = 0; i < 8; i++) {
int64_t res = input[0] * (INT64_C(1) << 23);
for (j = 0; j < 7; j++)
res += (int64_t)cos_mod[i][j] * input[1 + j];
output[i] = norm23(res);
}
}
static void mod_a(const int *input, int *output)
{
static const int cos_mod[16] = {
4199362, 4240198, 4323885, 4454708,
4639772, 4890013, 5221943, 5660703,
-6245623, -7040975, -8158494, -9809974,
-12450076, -17261920, -28585092, -85479984
};
int i, k;
for (i = 0; i < 8; i++)
output[i] = mul23(cos_mod[i], input[i] + input[8 + i]);
for (i = 8, k = 7; i < 16; i++, k--)
output[i] = mul23(cos_mod[i], input[k] - input[8 + k]);
}
static void mod_b(int *input, int *output)
{
static const int cos_mod[8] = {
4214598, 4383036, 4755871, 5425934,
6611520, 8897610, 14448934, 42791536
};
int i, k;
for (i = 0; i < 8; i++)
input[8 + i] = mul23(cos_mod[i], input[8 + i]);
for (i = 0; i < 8; i++)
output[i] = input[i] + input[8 + i];
for (i = 8, k = 7; i < 16; i++, k--)
output[i] = input[k] - input[8 + k];
}
static void mod_c(const int *input, int *output)
{
static const int cos_mod[32] = {
1048892, 1051425, 1056522, 1064244,
1074689, 1087987, 1104313, 1123884,
1146975, 1173922, 1205139, 1241133,
1282529, 1330095, 1384791, 1447815,
-1520688, -1605358, -1704360, -1821051,
-1959964, -2127368, -2332183, -2587535,
-2913561, -3342802, -3931480, -4785806,
-6133390, -8566050, -14253820, -42727120
};
int i, k;
for (i = 0; i < 16; i++)
output[i] = mul23(cos_mod[i], input[i] + input[16 + i]);
for (i = 16, k = 15; i < 32; i++, k--)
output[i] = mul23(cos_mod[i], input[k] - input[16 + k]);
}
static void clp_v(int *input, int len)
{
int i;
for (i = 0; i < len; i++)
input[i] = clip23(input[i]);
}
static void imdct_half_32(int32_t *output, const int32_t *input)
{
int buf_a[32], buf_b[32];
int i, k, mag, shift, round;
mag = 0;
for (i = 0; i < 32; i++)
mag += abs(input[i]);
shift = mag > 0x400000 ? 2 : 0;
round = shift > 0 ? 1 << (shift - 1) : 0;
for (i = 0; i < 32; i++)
buf_a[i] = (input[i] + round) >> shift;
sum_a(buf_a, buf_b + 0, 16);
sum_b(buf_a, buf_b + 16, 16);
clp_v(buf_b, 32);
sum_a(buf_b + 0, buf_a + 0, 8);
sum_b(buf_b + 0, buf_a + 8, 8);
sum_c(buf_b + 16, buf_a + 16, 8);
sum_d(buf_b + 16, buf_a + 24, 8);
clp_v(buf_a, 32);
dct_a(buf_a + 0, buf_b + 0);
dct_b(buf_a + 8, buf_b + 8);
dct_b(buf_a + 16, buf_b + 16);
dct_b(buf_a + 24, buf_b + 24);
clp_v(buf_b, 32);
mod_a(buf_b + 0, buf_a + 0);
mod_b(buf_b + 16, buf_a + 16);
clp_v(buf_a, 32);
mod_c(buf_a, buf_b);
for (i = 0; i < 32; i++)
buf_b[i] = clip23(buf_b[i] * (1 << shift));
for (i = 0, k = 31; i < 16; i++, k--) {
output[ i] = clip23(buf_b[i] - buf_b[k]);
output[16 + i] = clip23(buf_b[i] + buf_b[k]);
}
}
static void mod64_a(const int *input, int *output)
{
static const int cos_mod[32] = {
4195568, 4205700, 4226086, 4256977,
4298755, 4351949, 4417251, 4495537,
4587901, 4695690, 4820557, 4964534,
5130115, 5320382, 5539164, 5791261,
-6082752, -6421430, -6817439, -7284203,
-7839855, -8509474, -9328732, -10350140,
-11654242, -13371208, -15725922, -19143224,
-24533560, -34264200, -57015280, -170908480
};
int i, k;
for (i = 0; i < 16; i++)
output[i] = mul23(cos_mod[i], input[i] + input[16 + i]);
for (i = 16, k = 15; i < 32; i++, k--)
output[i] = mul23(cos_mod[i], input[k] - input[16 + k]);
}
static void mod64_b(int *input, int *output)
{
static const int cos_mod[16] = {
4199362, 4240198, 4323885, 4454708,
4639772, 4890013, 5221943, 5660703,
6245623, 7040975, 8158494, 9809974,
12450076, 17261920, 28585092, 85479984
};
int i, k;
for (i = 0; i < 16; i++)
input[16 + i] = mul23(cos_mod[i], input[16 + i]);
for (i = 0; i < 16; i++)
output[i] = input[i] + input[16 + i];
for (i = 16, k = 15; i < 32; i++, k--)
output[i] = input[k] - input[16 + k];
}
static void mod64_c(const int *input, int *output)
{
static const int cos_mod[64] = {
741511, 741958, 742853, 744199,
746001, 748262, 750992, 754197,
757888, 762077, 766777, 772003,
777772, 784105, 791021, 798546,
806707, 815532, 825054, 835311,
846342, 858193, 870912, 884554,
899181, 914860, 931667, 949686,
969011, 989747, 1012012, 1035941,
-1061684, -1089412, -1119320, -1151629,
-1186595, -1224511, -1265719, -1310613,
-1359657, -1413400, -1472490, -1537703,
-1609974, -1690442, -1780506, -1881904,
-1996824, -2128058, -2279225, -2455101,
-2662128, -2909200, -3208956, -3579983,
-4050785, -4667404, -5509372, -6726913,
-8641940, -12091426, -20144284, -60420720
};
int i, k;
for (i = 0; i < 32; i++)
output[i] = mul23(cos_mod[i], input[i] + input[32 + i]);
for (i = 32, k = 31; i < 64; i++, k--)
output[i] = mul23(cos_mod[i], input[k] - input[32 + k]);
}
static void imdct_half_64(int32_t *output, const int32_t *input)
{
int buf_a[64], buf_b[64];
int i, k, mag, shift, round;
mag = 0;
for (i = 0; i < 64; i++)
mag += abs(input[i]);
shift = mag > 0x400000 ? 2 : 0;
round = shift > 0 ? 1 << (shift - 1) : 0;
for (i = 0; i < 64; i++)
buf_a[i] = (input[i] + round) >> shift;
sum_a(buf_a, buf_b + 0, 32);
sum_b(buf_a, buf_b + 32, 32);
clp_v(buf_b, 64);
sum_a(buf_b + 0, buf_a + 0, 16);
sum_b(buf_b + 0, buf_a + 16, 16);
sum_c(buf_b + 32, buf_a + 32, 16);
sum_d(buf_b + 32, buf_a + 48, 16);
clp_v(buf_a, 64);
sum_a(buf_a + 0, buf_b + 0, 8);
sum_b(buf_a + 0, buf_b + 8, 8);
sum_c(buf_a + 16, buf_b + 16, 8);
sum_d(buf_a + 16, buf_b + 24, 8);
sum_c(buf_a + 32, buf_b + 32, 8);
sum_d(buf_a + 32, buf_b + 40, 8);
sum_c(buf_a + 48, buf_b + 48, 8);
sum_d(buf_a + 48, buf_b + 56, 8);
clp_v(buf_b, 64);
dct_a(buf_b + 0, buf_a + 0);
dct_b(buf_b + 8, buf_a + 8);
dct_b(buf_b + 16, buf_a + 16);
dct_b(buf_b + 24, buf_a + 24);
dct_b(buf_b + 32, buf_a + 32);
dct_b(buf_b + 40, buf_a + 40);
dct_b(buf_b + 48, buf_a + 48);
dct_b(buf_b + 56, buf_a + 56);
clp_v(buf_a, 64);
mod_a(buf_a + 0, buf_b + 0);
mod_b(buf_a + 16, buf_b + 16);
mod_b(buf_a + 32, buf_b + 32);
mod_b(buf_a + 48, buf_b + 48);
clp_v(buf_b, 64);
mod64_a(buf_b + 0, buf_a + 0);
mod64_b(buf_b + 32, buf_a + 32);
clp_v(buf_a, 64);
mod64_c(buf_a, buf_b);
for (i = 0; i < 64; i++)
buf_b[i] = clip23(buf_b[i] * (1 << shift));
for (i = 0, k = 63; i < 32; i++, k--) {
output[ i] = clip23(buf_b[i] - buf_b[k]);
output[32 + i] = clip23(buf_b[i] + buf_b[k]);
}
}
av_cold void ff_dcadct_init(DCADCTContext *c)
{
c->imdct_half[0] = imdct_half_32;
c->imdct_half[1] = imdct_half_64;
}