/*
  * 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"