mirror of https://git.ffmpeg.org/ffmpeg.git
371 lines
14 KiB
C
371 lines
14 KiB
C
/*
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* AAC Spectral Band Replication decoding functions
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* Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
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* Copyright (c) 2009-2010 Alex Converse <alex.converse@gmail.com>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* AAC Spectral Band Replication decoding functions
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* @author Robert Swain ( rob opendot cl )
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*/
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#define USE_FIXED 0
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#include "aac.h"
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#include "sbr.h"
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#include "aacsbr.h"
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#include "aacsbrdata.h"
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#include "aacsbr_tablegen.h"
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#include "fft.h"
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#include "internal.h"
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#include "aacps.h"
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#include "sbrdsp.h"
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#include "libavutil/internal.h"
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#include "libavutil/libm.h"
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#include "libavutil/avassert.h"
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#include <stdint.h>
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#include <float.h>
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#include <math.h>
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#if ARCH_MIPS
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#include "mips/aacsbr_mips.h"
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#endif /* ARCH_MIPS */
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static VLC vlc_sbr[10];
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static void aacsbr_func_ptr_init(AACSBRContext *c);
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static void make_bands(int16_t* bands, int start, int stop, int num_bands)
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{
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int k, previous, present;
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float base, prod;
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base = powf((float)stop / start, 1.0f / num_bands);
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prod = start;
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previous = start;
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for (k = 0; k < num_bands-1; k++) {
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prod *= base;
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present = lrintf(prod);
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bands[k] = present - previous;
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previous = present;
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}
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bands[num_bands-1] = stop - previous;
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}
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/// Dequantization and stereo decoding (14496-3 sp04 p203)
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static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)
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{
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int k, e;
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int ch;
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static const double exp2_tab[2] = {1, M_SQRT2};
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if (id_aac == TYPE_CPE && sbr->bs_coupling) {
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int pan_offset = sbr->data[0].bs_amp_res ? 12 : 24;
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for (e = 1; e <= sbr->data[0].bs_num_env; e++) {
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for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {
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float temp1, temp2, fac;
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if (sbr->data[0].bs_amp_res) {
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temp1 = ff_exp2fi(sbr->data[0].env_facs_q[e][k] + 7);
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temp2 = ff_exp2fi(pan_offset - sbr->data[1].env_facs_q[e][k]);
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}
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else {
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temp1 = ff_exp2fi((sbr->data[0].env_facs_q[e][k]>>1) + 7) *
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exp2_tab[sbr->data[0].env_facs_q[e][k] & 1];
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temp2 = ff_exp2fi((pan_offset - sbr->data[1].env_facs_q[e][k])>>1) *
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exp2_tab[(pan_offset - sbr->data[1].env_facs_q[e][k]) & 1];
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}
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if (temp1 > 1E20) {
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av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");
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temp1 = 1;
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}
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fac = temp1 / (1.0f + temp2);
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sbr->data[0].env_facs[e][k] = fac;
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sbr->data[1].env_facs[e][k] = fac * temp2;
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}
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}
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for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {
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for (k = 0; k < sbr->n_q; k++) {
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float temp1 = ff_exp2fi(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs_q[e][k] + 1);
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float temp2 = ff_exp2fi(12 - sbr->data[1].noise_facs_q[e][k]);
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float fac;
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av_assert0(temp1 <= 1E20);
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fac = temp1 / (1.0f + temp2);
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sbr->data[0].noise_facs[e][k] = fac;
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sbr->data[1].noise_facs[e][k] = fac * temp2;
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}
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}
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} else { // SCE or one non-coupled CPE
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for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {
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for (e = 1; e <= sbr->data[ch].bs_num_env; e++)
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for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++){
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if (sbr->data[ch].bs_amp_res)
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sbr->data[ch].env_facs[e][k] = ff_exp2fi(sbr->data[ch].env_facs_q[e][k] + 6);
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else
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sbr->data[ch].env_facs[e][k] = ff_exp2fi((sbr->data[ch].env_facs_q[e][k]>>1) + 6)
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* exp2_tab[sbr->data[ch].env_facs_q[e][k] & 1];
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if (sbr->data[ch].env_facs[e][k] > 1E20) {
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av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");
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sbr->data[ch].env_facs[e][k] = 1;
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}
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}
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for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)
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for (k = 0; k < sbr->n_q; k++)
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sbr->data[ch].noise_facs[e][k] =
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ff_exp2fi(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs_q[e][k]);
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}
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}
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}
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/** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering
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* (14496-3 sp04 p214)
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* Warning: This routine does not seem numerically stable.
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*/
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static void sbr_hf_inverse_filter(SBRDSPContext *dsp,
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float (*alpha0)[2], float (*alpha1)[2],
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const float X_low[32][40][2], int k0)
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{
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int k;
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for (k = 0; k < k0; k++) {
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LOCAL_ALIGNED_16(float, phi, [3], [2][2]);
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float dk;
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dsp->autocorrelate(X_low[k], phi);
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dk = phi[2][1][0] * phi[1][0][0] -
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(phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;
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if (!dk) {
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alpha1[k][0] = 0;
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alpha1[k][1] = 0;
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} else {
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float temp_real, temp_im;
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temp_real = phi[0][0][0] * phi[1][1][0] -
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phi[0][0][1] * phi[1][1][1] -
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phi[0][1][0] * phi[1][0][0];
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temp_im = phi[0][0][0] * phi[1][1][1] +
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phi[0][0][1] * phi[1][1][0] -
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phi[0][1][1] * phi[1][0][0];
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alpha1[k][0] = temp_real / dk;
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alpha1[k][1] = temp_im / dk;
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}
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if (!phi[1][0][0]) {
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alpha0[k][0] = 0;
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alpha0[k][1] = 0;
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} else {
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float temp_real, temp_im;
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temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +
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alpha1[k][1] * phi[1][1][1];
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temp_im = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -
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alpha1[k][0] * phi[1][1][1];
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alpha0[k][0] = -temp_real / phi[1][0][0];
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alpha0[k][1] = -temp_im / phi[1][0][0];
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}
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if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||
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alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {
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alpha1[k][0] = 0;
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alpha1[k][1] = 0;
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alpha0[k][0] = 0;
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alpha0[k][1] = 0;
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}
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}
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}
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/// Chirp Factors (14496-3 sp04 p214)
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static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)
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{
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int i;
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float new_bw;
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static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };
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for (i = 0; i < sbr->n_q; i++) {
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if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {
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new_bw = 0.6f;
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} else
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new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];
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if (new_bw < ch_data->bw_array[i]) {
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new_bw = 0.75f * new_bw + 0.25f * ch_data->bw_array[i];
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} else
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new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];
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ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;
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}
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}
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/**
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* Calculation of levels of additional HF signal components (14496-3 sp04 p219)
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* and Calculation of gain (14496-3 sp04 p219)
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*/
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static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,
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SBRData *ch_data, const int e_a[2])
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{
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int e, k, m;
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// max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)
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static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };
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for (e = 0; e < ch_data->bs_num_env; e++) {
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int delta = !((e == e_a[1]) || (e == e_a[0]));
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for (k = 0; k < sbr->n_lim; k++) {
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float gain_boost, gain_max;
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float sum[2] = { 0.0f, 0.0f };
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for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
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const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);
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sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);
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sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);
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if (!sbr->s_mapped[e][m]) {
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sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /
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((1.0f + sbr->e_curr[e][m]) *
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(1.0f + sbr->q_mapped[e][m] * delta)));
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} else {
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sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /
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((1.0f + sbr->e_curr[e][m]) *
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(1.0f + sbr->q_mapped[e][m])));
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}
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sbr->gain[e][m] += FLT_MIN;
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}
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for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
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sum[0] += sbr->e_origmapped[e][m];
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sum[1] += sbr->e_curr[e][m];
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}
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gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
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gain_max = FFMIN(100000.f, gain_max);
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for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
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float q_m_max = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];
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sbr->q_m[e][m] = FFMIN(sbr->q_m[e][m], q_m_max);
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sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);
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}
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sum[0] = sum[1] = 0.0f;
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for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
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sum[0] += sbr->e_origmapped[e][m];
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sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]
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+ sbr->s_m[e][m] * sbr->s_m[e][m]
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+ (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];
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}
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gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
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gain_boost = FFMIN(1.584893192f, gain_boost);
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for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
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sbr->gain[e][m] *= gain_boost;
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sbr->q_m[e][m] *= gain_boost;
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sbr->s_m[e][m] *= gain_boost;
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}
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}
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}
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}
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/// Assembling HF Signals (14496-3 sp04 p220)
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static void sbr_hf_assemble(float Y1[38][64][2],
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const float X_high[64][40][2],
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SpectralBandReplication *sbr, SBRData *ch_data,
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const int e_a[2])
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{
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int e, i, j, m;
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const int h_SL = 4 * !sbr->bs_smoothing_mode;
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const int kx = sbr->kx[1];
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const int m_max = sbr->m[1];
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static const float h_smooth[5] = {
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0.33333333333333,
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0.30150283239582,
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0.21816949906249,
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0.11516383427084,
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0.03183050093751,
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};
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float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;
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int indexnoise = ch_data->f_indexnoise;
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int indexsine = ch_data->f_indexsine;
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if (sbr->reset) {
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for (i = 0; i < h_SL; i++) {
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memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));
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memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0], m_max * sizeof(sbr->q_m[0][0]));
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}
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} else if (h_SL) {
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for (i = 0; i < 4; i++) {
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memcpy(g_temp[i + 2 * ch_data->t_env[0]],
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g_temp[i + 2 * ch_data->t_env_num_env_old],
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sizeof(g_temp[0]));
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memcpy(q_temp[i + 2 * ch_data->t_env[0]],
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q_temp[i + 2 * ch_data->t_env_num_env_old],
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sizeof(q_temp[0]));
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}
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}
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for (e = 0; e < ch_data->bs_num_env; e++) {
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for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
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memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));
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memcpy(q_temp[h_SL + i], sbr->q_m[e], m_max * sizeof(sbr->q_m[0][0]));
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}
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}
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for (e = 0; e < ch_data->bs_num_env; e++) {
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for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
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LOCAL_ALIGNED_16(float, g_filt_tab, [48]);
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LOCAL_ALIGNED_16(float, q_filt_tab, [48]);
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float *g_filt, *q_filt;
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if (h_SL && e != e_a[0] && e != e_a[1]) {
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g_filt = g_filt_tab;
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q_filt = q_filt_tab;
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for (m = 0; m < m_max; m++) {
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const int idx1 = i + h_SL;
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g_filt[m] = 0.0f;
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q_filt[m] = 0.0f;
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for (j = 0; j <= h_SL; j++) {
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g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];
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q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];
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}
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}
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} else {
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g_filt = g_temp[i + h_SL];
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q_filt = q_temp[i];
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}
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sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,
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i + ENVELOPE_ADJUSTMENT_OFFSET);
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if (e != e_a[0] && e != e_a[1]) {
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sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],
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q_filt, indexnoise,
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kx, m_max);
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} else {
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int idx = indexsine&1;
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int A = (1-((indexsine+(kx & 1))&2));
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int B = (A^(-idx)) + idx;
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float *out = &Y1[i][kx][idx];
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float *in = sbr->s_m[e];
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for (m = 0; m+1 < m_max; m+=2) {
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out[2*m ] += in[m ] * A;
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out[2*m+2] += in[m+1] * B;
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}
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if(m_max&1)
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out[2*m ] += in[m ] * A;
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}
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indexnoise = (indexnoise + m_max) & 0x1ff;
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indexsine = (indexsine + 1) & 3;
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}
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}
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ch_data->f_indexnoise = indexnoise;
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ch_data->f_indexsine = indexsine;
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}
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#include "aacsbr_template.c"
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