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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 */ /** * @file * AAC Spectral Band Replication decoding functions * @author Robert Swain ( rob opendot cl ) */#define USE_FIXED 0 #include "aac.h"#include "sbr.h"#include "aacsbr.h"#include "aacsbrdata.h"#include "aacsbr_tablegen.h"#include "fft.h"#include "internal.h"#include "aacps.h"#include "sbrdsp.h"#include "libavutil/internal.h"#include "libavutil/libm.h"#include "libavutil/avassert.h" #include <stdint.h>#include <float.h>#include <math.h> #if ARCH_MIPS#include "mips/aacsbr_mips.h"#endif /* ARCH_MIPS */ static VLC vlc_sbr[10];static void aacsbr_func_ptr_init(AACSBRContext *c); static void make_bands(int16_t* bands, int start, int stop, int num_bands){    int k, previous, present;    float base, prod;     base = powf((float)stop / start, 1.0f / num_bands);    prod = start;    previous = start;     for (k = 0; k < num_bands-1; k++) {        prod *= base;        present  = lrintf(prod);        bands[k] = present - previous;        previous = present;    }    bands[num_bands-1] = stop - previous;} /// Dequantization and stereo decoding (14496-3 sp04 p203)static void sbr_dequant(SpectralBandReplication *sbr, int id_aac){    int k, e;    int ch;    static const double exp2_tab[2] = {1, M_SQRT2};    if (id_aac == TYPE_CPE && sbr->bs_coupling) {        int pan_offset = sbr->data[0].bs_amp_res ? 12 : 24;        for (e = 1; e <= sbr->data[0].bs_num_env; e++) {            for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {                float temp1, temp2, fac;                if (sbr->data[0].bs_amp_res) {                    temp1 = ff_exp2fi(sbr->data[0].env_facs_q[e][k] + 7);                    temp2 = ff_exp2fi(pan_offset - sbr->data[1].env_facs_q[e][k]);                }                else {                    temp1 = ff_exp2fi((sbr->data[0].env_facs_q[e][k]>>1) + 7) *                            exp2_tab[sbr->data[0].env_facs_q[e][k] & 1];                    temp2 = ff_exp2fi((pan_offset - sbr->data[1].env_facs_q[e][k])>>1) *                            exp2_tab[(pan_offset - sbr->data[1].env_facs_q[e][k]) & 1];                }                if (temp1 > 1E20) {                    av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");                    temp1 = 1;                }                fac   = temp1 / (1.0f + temp2);                sbr->data[0].env_facs[e][k] = fac;                sbr->data[1].env_facs[e][k] = fac * temp2;            }        }        for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {            for (k = 0; k < sbr->n_q; k++) {                float temp1 = ff_exp2fi(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs_q[e][k] + 1);                float temp2 = ff_exp2fi(12 - sbr->data[1].noise_facs_q[e][k]);                float fac;                av_assert0(temp1 <= 1E20);                fac = temp1 / (1.0f + temp2);                sbr->data[0].noise_facs[e][k] = fac;                sbr->data[1].noise_facs[e][k] = fac * temp2;            }        }    } else { // SCE or one non-coupled CPE        for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {            for (e = 1; e <= sbr->data[ch].bs_num_env; e++)                for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++){                    if (sbr->data[ch].bs_amp_res)                        sbr->data[ch].env_facs[e][k] = ff_exp2fi(sbr->data[ch].env_facs_q[e][k] + 6);                    else                        sbr->data[ch].env_facs[e][k] = ff_exp2fi((sbr->data[ch].env_facs_q[e][k]>>1) + 6)                                                       * exp2_tab[sbr->data[ch].env_facs_q[e][k] & 1];                    if (sbr->data[ch].env_facs[e][k] > 1E20) {                        av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");                        sbr->data[ch].env_facs[e][k] = 1;                    }                }             for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)                for (k = 0; k < sbr->n_q; k++)                    sbr->data[ch].noise_facs[e][k] =                        ff_exp2fi(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs_q[e][k]);        }    }} /** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering * (14496-3 sp04 p214) * Warning: This routine does not seem numerically stable. */static void sbr_hf_inverse_filter(SBRDSPContext *dsp,                                  float (*alpha0)[2], float (*alpha1)[2],                                  const float X_low[32][40][2], int k0){    int k;    for (k = 0; k < k0; k++) {        LOCAL_ALIGNED_16(float, phi, [3], [2][2]);        float dk;         dsp->autocorrelate(X_low[k], phi);         dk =  phi[2][1][0] * phi[1][0][0] -             (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;         if (!dk) {            alpha1[k][0] = 0;            alpha1[k][1] = 0;        } else {            float temp_real, temp_im;            temp_real = phi[0][0][0] * phi[1][1][0] -                        phi[0][0][1] * phi[1][1][1] -                        phi[0][1][0] * phi[1][0][0];            temp_im   = phi[0][0][0] * phi[1][1][1] +                        phi[0][0][1] * phi[1][1][0] -                        phi[0][1][1] * phi[1][0][0];             alpha1[k][0] = temp_real / dk;            alpha1[k][1] = temp_im   / dk;        }         if (!phi[1][0][0]) {            alpha0[k][0] = 0;            alpha0[k][1] = 0;        } else {            float temp_real, temp_im;            temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +                                       alpha1[k][1] * phi[1][1][1];            temp_im   = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -                                       alpha1[k][0] * phi[1][1][1];             alpha0[k][0] = -temp_real / phi[1][0][0];            alpha0[k][1] = -temp_im   / phi[1][0][0];        }         if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||           alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {            alpha1[k][0] = 0;            alpha1[k][1] = 0;            alpha0[k][0] = 0;            alpha0[k][1] = 0;        }    }} /// Chirp Factors (14496-3 sp04 p214)static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data){    int i;    float new_bw;    static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };     for (i = 0; i < sbr->n_q; i++) {        if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {            new_bw = 0.6f;        } else            new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];         if (new_bw < ch_data->bw_array[i]) {            new_bw = 0.75f    * new_bw + 0.25f    * ch_data->bw_array[i];        } else            new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];        ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;    }} /** * Calculation of levels of additional HF signal components (14496-3 sp04 p219) * and Calculation of gain (14496-3 sp04 p219) */static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,                          SBRData *ch_data, const int e_a[2]){    int e, k, m;    // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)    static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };     for (e = 0; e < ch_data->bs_num_env; e++) {        int delta = !((e == e_a[1]) || (e == e_a[0]));        for (k = 0; k < sbr->n_lim; k++) {            float gain_boost, gain_max;            float sum[2] = { 0.0f, 0.0f };            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {                const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);                sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);                sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);                if (!sbr->s_mapped[e][m]) {                    sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /                                            ((1.0f + sbr->e_curr[e][m]) *                                             (1.0f + sbr->q_mapped[e][m] * delta)));                } else {                    sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /                                            ((1.0f + sbr->e_curr[e][m]) *                                             (1.0f + sbr->q_mapped[e][m])));                }                sbr->gain[e][m] += FLT_MIN;            }            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {                sum[0] += sbr->e_origmapped[e][m];                sum[1] += sbr->e_curr[e][m];            }            gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));            gain_max = FFMIN(100000.f, gain_max);            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {                float q_m_max   = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];                sbr->q_m[e][m]  = FFMIN(sbr->q_m[e][m], q_m_max);                sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);            }            sum[0] = sum[1] = 0.0f;            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {                sum[0] += sbr->e_origmapped[e][m];                sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]                          + sbr->s_m[e][m] * sbr->s_m[e][m]                          + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];            }            gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));            gain_boost = FFMIN(1.584893192f, gain_boost);            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {                sbr->gain[e][m] *= gain_boost;                sbr->q_m[e][m]  *= gain_boost;                sbr->s_m[e][m]  *= gain_boost;            }        }    }} /// Assembling HF Signals (14496-3 sp04 p220)static void sbr_hf_assemble(float Y1[38][64][2],                            const float X_high[64][40][2],                            SpectralBandReplication *sbr, SBRData *ch_data,                            const int e_a[2]){    int e, i, j, m;    const int h_SL = 4 * !sbr->bs_smoothing_mode;    const int kx = sbr->kx[1];    const int m_max = sbr->m[1];    static const float h_smooth[5] = {        0.33333333333333,        0.30150283239582,        0.21816949906249,        0.11516383427084,        0.03183050093751,    };    float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;    int indexnoise = ch_data->f_indexnoise;    int indexsine  = ch_data->f_indexsine;     if (sbr->reset) {        for (i = 0; i < h_SL; i++) {            memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));            memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0],  m_max * sizeof(sbr->q_m[0][0]));        }    } else if (h_SL) {        for (i = 0; i < 4; i++) {            memcpy(g_temp[i + 2 * ch_data->t_env[0]],                   g_temp[i + 2 * ch_data->t_env_num_env_old],                   sizeof(g_temp[0]));            memcpy(q_temp[i + 2 * ch_data->t_env[0]],                   q_temp[i + 2 * ch_data->t_env_num_env_old],                   sizeof(q_temp[0]));        }    }     for (e = 0; e < ch_data->bs_num_env; e++) {        for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {            memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));            memcpy(q_temp[h_SL + i], sbr->q_m[e],  m_max * sizeof(sbr->q_m[0][0]));        }    }     for (e = 0; e < ch_data->bs_num_env; e++) {        for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {            LOCAL_ALIGNED_16(float, g_filt_tab, [48]);            LOCAL_ALIGNED_16(float, q_filt_tab, [48]);            float *g_filt, *q_filt;             if (h_SL && e != e_a[0] && e != e_a[1]) {                g_filt = g_filt_tab;                q_filt = q_filt_tab;                for (m = 0; m < m_max; m++) {                    const int idx1 = i + h_SL;                    g_filt[m] = 0.0f;                    q_filt[m] = 0.0f;                    for (j = 0; j <= h_SL; j++) {                        g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];                        q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];                    }                }            } else {                g_filt = g_temp[i + h_SL];                q_filt = q_temp[i];            }             sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,                               i + ENVELOPE_ADJUSTMENT_OFFSET);             if (e != e_a[0] && e != e_a[1]) {                sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],                                                   q_filt, indexnoise,                                                   kx, m_max);            } else {                int idx = indexsine&1;                int A = (1-((indexsine+(kx & 1))&2));                int B = (A^(-idx)) + idx;                float *out = &Y1[i][kx][idx];                float *in  = sbr->s_m[e];                for (m = 0; m+1 < m_max; m+=2) {                    out[2*m  ] += in[m  ] * A;                    out[2*m+2] += in[m+1] * B;                }                if(m_max&1)                    out[2*m  ] += in[m  ] * A;            }            indexnoise = (indexnoise + m_max) & 0x1ff;            indexsine = (indexsine + 1) & 3;        }    }    ch_data->f_indexnoise = indexnoise;    ch_data->f_indexsine  = indexsine;} #include "aacsbr_template.c"

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