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ffmpeg/libavcodec/sbrdsp_fixed.c

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/*
* AAC Spectral Band Replication decoding functions
* Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
* Copyright (c) 2009-2010 Alex Converse <alex.converse@gmail.com>
*
* 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
*
* Note: Rounding-to-nearest used unless otherwise stated
*
*/
#define USE_FIXED 1
#include "aac.h"
#include "config.h"
#include "libavutil/attributes.h"
#include "libavutil/intfloat.h"
#include "sbrdsp.h"
static SoftFloat sbr_sum_square_c(int (*x)[2], int n)
{
SoftFloat ret;
int64_t accu = 0;
int i, nz, round;
for (i = 0; i < n; i += 2) {
// Larger values are inavlid and could cause overflows of accu.
av_assert2(FFABS(x[i + 0][0]) >> 29 == 0);
accu += (int64_t)x[i + 0][0] * x[i + 0][0];
av_assert2(FFABS(x[i + 0][1]) >> 29 == 0);
accu += (int64_t)x[i + 0][1] * x[i + 0][1];
av_assert2(FFABS(x[i + 1][0]) >> 29 == 0);
accu += (int64_t)x[i + 1][0] * x[i + 1][0];
av_assert2(FFABS(x[i + 1][1]) >> 29 == 0);
accu += (int64_t)x[i + 1][1] * x[i + 1][1];
}
i = (int)(accu >> 32);
if (i == 0) {
nz = 1;
} else {
nz = 0;
while (FFABS(i) < 0x40000000) {
i <<= 1;
nz++;
}
nz = 32 - nz;
}
round = 1 << (nz-1);
i = (int)((accu + round) >> nz);
i >>= 1;
ret = av_int2sf(i, 15 - nz);
return ret;
}
static void sbr_neg_odd_64_c(int *x)
{
int i;
for (i = 1; i < 64; i += 2)
x[i] = -x[i];
}
static void sbr_qmf_pre_shuffle_c(int *z)
{
int k;
z[64] = z[0];
z[65] = z[1];
for (k = 1; k < 32; k++) {
z[64+2*k ] = -z[64 - k];
z[64+2*k+1] = z[ k + 1];
}
}
static void sbr_qmf_post_shuffle_c(int W[32][2], const int *z)
{
int k;
for (k = 0; k < 32; k++) {
W[k][0] = -z[63-k];
W[k][1] = z[k];
}
}
static void sbr_qmf_deint_neg_c(int *v, const int *src)
{
int i;
for (i = 0; i < 32; i++) {
v[ i] = ( src[63 - 2*i ] + 0x10) >> 5;
v[63 - i] = (-src[63 - 2*i - 1] + 0x10) >> 5;
}
}
static av_always_inline SoftFloat autocorr_calc(int64_t accu)
{
int nz, mant, expo, round;
int i = (int)(accu >> 32);
if (i == 0) {
nz = 1;
} else {
nz = 0;
while (FFABS(i) < 0x40000000) {
i <<= 1;
nz++;
}
nz = 32-nz;
}
round = 1 << (nz-1);
mant = (int)((accu + round) >> nz);
mant = (mant + 0x40)>>7;
mant <<= 6;
expo = nz + 15;
return av_int2sf(mant, 30 - expo);
}
static av_always_inline void autocorrelate(const int x[40][2], SoftFloat phi[3][2][2], int lag)
{
int i;
int64_t real_sum, imag_sum;
int64_t accu_re = 0, accu_im = 0;
if (lag) {
for (i = 1; i < 38; i++) {
accu_re += (int64_t)x[i][0] * x[i+lag][0];
accu_re += (int64_t)x[i][1] * x[i+lag][1];
accu_im += (int64_t)x[i][0] * x[i+lag][1];
accu_im -= (int64_t)x[i][1] * x[i+lag][0];
}
real_sum = accu_re;
imag_sum = accu_im;
accu_re += (int64_t)x[ 0][0] * x[lag][0];
accu_re += (int64_t)x[ 0][1] * x[lag][1];
accu_im += (int64_t)x[ 0][0] * x[lag][1];
accu_im -= (int64_t)x[ 0][1] * x[lag][0];
phi[2-lag][1][0] = autocorr_calc(accu_re);
phi[2-lag][1][1] = autocorr_calc(accu_im);
if (lag == 1) {
accu_re = real_sum;
accu_im = imag_sum;
accu_re += (int64_t)x[38][0] * x[39][0];
accu_re += (int64_t)x[38][1] * x[39][1];
accu_im += (int64_t)x[38][0] * x[39][1];
accu_im -= (int64_t)x[38][1] * x[39][0];
phi[0][0][0] = autocorr_calc(accu_re);
phi[0][0][1] = autocorr_calc(accu_im);
}
} else {
for (i = 1; i < 38; i++) {
accu_re += (int64_t)x[i][0] * x[i][0];
accu_re += (int64_t)x[i][1] * x[i][1];
}
real_sum = accu_re;
accu_re += (int64_t)x[ 0][0] * x[ 0][0];
accu_re += (int64_t)x[ 0][1] * x[ 0][1];
phi[2][1][0] = autocorr_calc(accu_re);
accu_re = real_sum;
accu_re += (int64_t)x[38][0] * x[38][0];
accu_re += (int64_t)x[38][1] * x[38][1];
phi[1][0][0] = autocorr_calc(accu_re);
}
}
static void sbr_autocorrelate_c(const int x[40][2], SoftFloat phi[3][2][2])
{
autocorrelate(x, phi, 0);
autocorrelate(x, phi, 1);
autocorrelate(x, phi, 2);
}
static void sbr_hf_gen_c(int (*X_high)[2], const int (*X_low)[2],
const int alpha0[2], const int alpha1[2],
int bw, int start, int end)
{
int alpha[4];
int i;
int64_t accu;
accu = (int64_t)alpha0[0] * bw;
alpha[2] = (int)((accu + 0x40000000) >> 31);
accu = (int64_t)alpha0[1] * bw;
alpha[3] = (int)((accu + 0x40000000) >> 31);
accu = (int64_t)bw * bw;
bw = (int)((accu + 0x40000000) >> 31);
accu = (int64_t)alpha1[0] * bw;
alpha[0] = (int)((accu + 0x40000000) >> 31);
accu = (int64_t)alpha1[1] * bw;
alpha[1] = (int)((accu + 0x40000000) >> 31);
for (i = start; i < end; i++) {
accu = (int64_t)X_low[i][0] * 0x20000000;
accu += (int64_t)X_low[i - 2][0] * alpha[0];
accu -= (int64_t)X_low[i - 2][1] * alpha[1];
accu += (int64_t)X_low[i - 1][0] * alpha[2];
accu -= (int64_t)X_low[i - 1][1] * alpha[3];
X_high[i][0] = (int)((accu + 0x10000000) >> 29);
accu = (int64_t)X_low[i][1] * 0x20000000;
accu += (int64_t)X_low[i - 2][1] * alpha[0];
accu += (int64_t)X_low[i - 2][0] * alpha[1];
accu += (int64_t)X_low[i - 1][1] * alpha[2];
accu += (int64_t)X_low[i - 1][0] * alpha[3];
X_high[i][1] = (int)((accu + 0x10000000) >> 29);
}
}
static void sbr_hf_g_filt_c(int (*Y)[2], const int (*X_high)[40][2],
const SoftFloat *g_filt, int m_max, intptr_t ixh)
{
int m, r;
int64_t accu;
for (m = 0; m < m_max; m++) {
r = 1 << (22-g_filt[m].exp);
accu = (int64_t)X_high[m][ixh][0] * ((g_filt[m].mant + 0x40)>>7);
Y[m][0] = (int)((accu + r) >> (23-g_filt[m].exp));
accu = (int64_t)X_high[m][ixh][1] * ((g_filt[m].mant + 0x40)>>7);
Y[m][1] = (int)((accu + r) >> (23-g_filt[m].exp));
}
}
static av_always_inline void sbr_hf_apply_noise(int (*Y)[2],
const SoftFloat *s_m,
const SoftFloat *q_filt,
int noise,
int phi_sign0,
int phi_sign1,
int m_max)
{
int m;
for (m = 0; m < m_max; m++) {
int y0 = Y[m][0];
int y1 = Y[m][1];
noise = (noise + 1) & 0x1ff;
if (s_m[m].mant) {
int shift, round;
shift = 22 - s_m[m].exp;
if (shift < 30) {
round = 1 << (shift-1);
y0 += (s_m[m].mant * phi_sign0 + round) >> shift;
y1 += (s_m[m].mant * phi_sign1 + round) >> shift;
}
} else {
int shift, round, tmp;
int64_t accu;
shift = 22 - q_filt[m].exp;
if (shift < 30) {
round = 1 << (shift-1);
accu = (int64_t)q_filt[m].mant * ff_sbr_noise_table_fixed[noise][0];
tmp = (int)((accu + 0x40000000) >> 31);
y0 += (tmp + round) >> shift;
accu = (int64_t)q_filt[m].mant * ff_sbr_noise_table_fixed[noise][1];
tmp = (int)((accu + 0x40000000) >> 31);
y1 += (tmp + round) >> shift;
}
}
Y[m][0] = y0;
Y[m][1] = y1;
phi_sign1 = -phi_sign1;
}
}
#include "sbrdsp_template.c"
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