ref: 6c93b4fdda100e449e25d57102a44d9bb63318b0
dir: /libfaad/sbr_qmf.c/
/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003 M. Bakker, Ahead Software AG, http://www.nero.com
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** Any non-GPL usage of this software or parts of this software is strictly
** forbidden.
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
**
** $Id: sbr_qmf.c,v 1.5 2003/07/29 08:20:13 menno Exp $
**/
#include "common.h"
#include "structs.h"
#ifdef SBR_DEC
#include <stdlib.h>
#include <string.h>
#include "sbr_dct.h"
#include "sbr_qmf.h"
#include "sbr_syntax.h"
qmfa_info *qmfa_init(uint8_t channels)
{
#if 0
int16_t n;
#endif
int size = 0;
qmfa_info *qmfa = (qmfa_info*)malloc(sizeof(qmfa_info));
qmfa->x = (real_t*)malloc(channels * 10 * sizeof(real_t));
memset(qmfa->x, 0, channels * 10 * sizeof(real_t));
qmfa->channels = channels;
if (channels == 32)
{
#if 0
for (n = 0; n < 32; n++)
{
qmfa->post_exp_re[n] = cos((M_PI/32.)*(0.75*n + 0.375));
qmfa->post_exp_im[n] = sin((M_PI/32.)*(0.75*n + 0.375));
}
#endif
} else if (channels == 64) {
#if 0
for (n = 0; n < 2*channels; n++)
{
qmfa->pre_exp_re[n] = cos(M_PI*n/(2.*channels));
qmfa->pre_exp_im[n] = sin(M_PI*n/(2.*channels));
}
for (n = 0; n < 64; n++)
{
qmfa->post_exp_re[n] = cos(M_PI*(2*n+1)/(2.*128.));
qmfa->post_exp_im[n] = sin(M_PI*(2*n+1)/(2.*128.));
}
#endif
}
return qmfa;
}
void qmfa_end(qmfa_info *qmfa)
{
if (qmfa)
{
if (qmfa->x) free(qmfa->x);
free(qmfa);
}
}
void sbr_qmf_analysis_32(qmfa_info *qmfa, const real_t *input,
qmf_t *X, uint8_t offset)
{
uint8_t l;
real_t u[64];
#ifndef SBR_LOW_POWER
real_t x[64], y[64];
#else
real_t y[32];
#endif
const real_t *inptr = input;
/* qmf subsample l */
for (l = 0; l < 32; l++)
{
int16_t n;
/* shift input buffer x */
memmove(qmfa->x + 32, qmfa->x, (320-32)*sizeof(real_t));
/* add new samples to input buffer x */
for (n = 32 - 1; n >= 0; n--)
{
#ifdef FIXED_POINT
qmfa->x[n] = (*inptr++) >> 5;
#else
qmfa->x[n] = *inptr++;
#endif
}
/* window and summation to create array u */
for (n = 0; n < 64; n++)
{
u[n] = MUL_R_C(qmfa->x[n], qmf_c_2[n]) +
MUL_R_C(qmfa->x[n + 64], qmf_c_2[n + 64]) +
MUL_R_C(qmfa->x[n + 128], qmf_c_2[n + 128]) +
MUL_R_C(qmfa->x[n + 192], qmf_c_2[n + 192]) +
MUL_R_C(qmfa->x[n + 256], qmf_c_2[n + 256]);
}
/* calculate 32 subband samples by introducing X */
#ifdef SBR_LOW_POWER
y[0] = u[48];
for (n = 1; n < 16; n++)
y[n] = u[n+48] + u[48-n];
for (n = 16; n < 32; n++)
y[n] = -u[n-16] + u[48-n];
DCT3_32_unscaled(u, y);
for (n = 0; n < 32; n++)
{
#ifdef FIXED_POINT
QMF_RE(X[((l + offset)<<5) + n]) = u[n] << 1;
#else
QMF_RE(X[((l + offset)<<5) + n]) = 2. * u[n];
#endif
#if 0
if (fabs(QMF_RE(X[((l + offset)<<5) + n])) > pow(2,20))
{
printf("%f\n", QMF_RE(X[((l + offset)<<5) + n]));
}
#endif
}
#else
x[0] = u[0];
x[63] = u[32];
for (n = 2; n < 64; n += 2)
{
x[n-1] = u[(n>>1)];
x[n] = -u[64-(n>>1)];
}
DCT4_64(y, x);
for (n = 0; n < 32; n++)
{
#ifdef FIXED_POINT
QMF_RE(X[((l + offset)<<5) + n]) = y[n] << 1;
QMF_IM(X[((l + offset)<<5) + n]) = -y[63-n] << 1;
#else
QMF_RE(X[((l + offset)<<5) + n]) = 2. * y[n];
QMF_IM(X[((l + offset)<<5) + n]) = -2. * y[63-n];
#endif
#if 0
if (fabs(QMF_RE(X[((l + offset)<<5) + n])) > pow(2,20))
{
printf("%f\n", QMF_RE(X[((l + offset)<<5) + n]));
}
if (fabs(QMF_IM(X[((l + offset)<<5) + n])) > pow(2,20))
{
printf("%f\n", QMF_IM(X[((l + offset)<<5) + n]));
}
#endif
}
#endif
}
}
qmfs_info *qmfs_init(uint8_t channels)
{
int size = 0;
qmfs_info *qmfs = (qmfs_info*)malloc(sizeof(qmfs_info));
qmfs->v = (real_t*)malloc(channels * 20 * sizeof(real_t));
memset(qmfs->v, 0, channels * 20 * sizeof(real_t));
qmfs->channels = channels;
return qmfs;
}
void qmfs_end(qmfs_info *qmfs)
{
if (qmfs)
{
if (qmfs->v) free(qmfs->v);
free(qmfs);
}
}
#if 0
void sbr_qmf_synthesis_32(qmfs_info *qmfs, const complex_t *X,
real_t *output)
{
uint8_t l;
int16_t n, k;
real_t w[320];
complex_t x[128];
real_t *outptr = output;
/* qmf subsample l */
for (l = 0; l < 32; l++)
{
/* shift buffer */
for (n = 640 - 1; n >= 64; n--)
{
qmfs->v[n] = qmfs->v[n - 64];
}
/* calculate 64 samples */
memset(x, 0, 2*64*sizeof(real_t));
for (k = 0; k < 32; k++)
{
real_t er, ei, Xr, Xi;
er = qmfs->pre_exp_re[k];
ei = qmfs->pre_exp_im[k];
Xr = RE(X[l * 32 + k]);
Xi = IM(X[l * 32 + k]);
RE(x[k]) = Xr * er - Xi * ei;
IM(x[k]) = Xi * er + Xr * ei;
}
cfftb(qmfs->cffts, x);
for (n = 0; n < 64; n++)
{
real_t er, ei;
er = qmfs->post_exp_re[n];
ei = qmfs->post_exp_im[n];
qmfs->v[n] = RE(x[n]) * er - IM(x[n]) * ei;
}
for (n = 0; n < 5; n++)
{
for (k = 0; k < 32; k++)
{
w[64 * n + k] = qmfs->v[128 * n + k];
w[64 * n + 32 + k] = qmfs->v[128 * n + 96 + k];
}
}
/* window */
for (n = 0; n < 320; n++)
{
w[n] *= qmf_c_2[n];
}
/* calculate 32 output samples */
for (k = 0; k < 32; k++)
{
real_t sample = 0.0;
for (n = 0; n < 10; n++)
{
sample += w[32 * n + k];
}
*outptr++ = sample;
}
}
}
#endif
void sbr_qmf_synthesis_64(qmfs_info *qmfs, const qmf_t *X,
real_t *output)
{
uint8_t l;
int16_t n, k;
#ifdef SBR_LOW_POWER
real_t x[64];
#else
real_t x1[64], x2[64];
#endif
real_t *outptr = output;
/* qmf subsample l */
for (l = 0; l < 32; l++)
{
/* shift buffer */
memmove(qmfs->v + 128, qmfs->v, (1280-128)*sizeof(real_t));
/* calculate 128 samples */
#ifdef SBR_LOW_POWER
for (k = 0; k < 64; k++)
{
#ifdef FIXED_POINT
x[k] = QMF_RE(X[(l<<6) + k]);
#else
x[k] = QMF_RE(X[(l<<6) + k]) / 32.;
#endif
}
DCT2_64_unscaled(x, x);
for (n = 0; n < 64; n++)
{
qmfs->v[n+32] = x[n];
}
qmfs->v[0] = qmfs->v[64];
for (n = 1; n < 32; n++)
{
qmfs->v[32 - n] = qmfs->v[n + 32];
qmfs->v[n + 96] = -qmfs->v[96 - n];
}
#else
for (k = 0; k < 64; k++)
{
x1[k] = QMF_RE(X[(l<<6) + k])/64.;
x2[k] = QMF_IM(X[(l<<6) + k])/64.;
}
DCT4_64(x1, x1);
DST4_64(x2, x2);
for (n = 0; n < 64; n++)
{
qmfs->v[n] = x2[n] - x1[n];
qmfs->v[127-n] = x2[n] + x1[n];
}
#endif
/* calculate 64 output samples and window */
for (k = 0; k < 64; k++)
{
*outptr++ = MUL_R_C(qmfs->v[k], qmf_c[k]) +
MUL_R_C(qmfs->v[192 + k], qmf_c[64 + k]) +
MUL_R_C(qmfs->v[256 + k], qmf_c[128 + k]) +
MUL_R_C(qmfs->v[256 + 192 + k], qmf_c[128 + 64 + k]) +
MUL_R_C(qmfs->v[512 + k], qmf_c[256 + k]) +
MUL_R_C(qmfs->v[512 + 192 + k], qmf_c[256 + 64 + k]) +
MUL_R_C(qmfs->v[768 + k], qmf_c[384 + k]) +
MUL_R_C(qmfs->v[768 + 192 + k], qmf_c[384 + 64 + k]) +
MUL_R_C(qmfs->v[1024 + k], qmf_c[512 + k]) +
MUL_R_C(qmfs->v[1024 + 192 + k], qmf_c[512 + 64 + k]);
}
}
}
#endif