/*
  * SIPR decoder for the 16k mode
  *
  * Copyright (c) 2008 Vladimir Voroshilov
  * Copyright (c) 2009 Vitor Sessak
  *
  * 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
  */
 
 #include <math.h>
 
 #include "sipr.h"

 #include "libavutil/attributes.h"

 #include "libavutil/common.h"

 #include "libavutil/float_dsp.h"

 #include "libavutil/mathematics.h"
 #include "lsp.h"
 #include "acelp_vectors.h"
 #include "acelp_pitch_delay.h"
 #include "acelp_filters.h"
 #include "celp_filters.h"
 
 #include "sipr16kdata.h"
 
 /**
  * Convert an lsf vector into an lsp vector.
  *
  * @param lsf               input lsf vector
  * @param lsp               output lsp vector
  */
 static void lsf2lsp(const float *lsf, double *lsp)
 {
     int i;
 
     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
         lsp[i] = cosf(lsf[i]);
 }
 

 static void dequant(float *out, const int *idx, const float * const cbs[])

 {
     int i;
 
     for (i = 0; i < 4; i++)
         memcpy(out + 3*i, cbs[i] + 3*idx[i], 3*sizeof(float));
 
     memcpy(out + 12, cbs[4] + 4*idx[4], 4*sizeof(float));
 }
 
 static void lsf_decode_fp_16k(float* lsf_history, float* isp_new,
                               const int* parm, int ma_pred)
 {
     int i;
     float isp_q[LP_FILTER_ORDER_16k];
 
     dequant(isp_q, parm, lsf_codebooks_16k);
 
     for (i = 0; i < LP_FILTER_ORDER_16k; i++) {
         isp_new[i] = (1 - qu[ma_pred]) * isp_q[i]
                     +     qu[ma_pred]  * lsf_history[i]
                     + mean_lsf_16k[i];
     }
 
     memcpy(lsf_history, isp_q, LP_FILTER_ORDER_16k * sizeof(float));
 }
 
 static int dec_delay3_1st(int index)
 {
     if (index < 390) {
         return index + 88;
     } else
         return 3 * index - 690;
 }
 
 static int dec_delay3_2nd(int index, int pit_min, int pit_max,
                           int pitch_lag_prev)
 {
     if (index < 62) {
         int pitch_delay_min = av_clip(pitch_lag_prev - 10,
                                       pit_min, pit_max - 19);
         return 3 * pitch_delay_min + index - 2;
     } else
         return 3 * pitch_lag_prev;
 }
 

 static void postfilter(float *out_data, float* synth, float* iir_mem,
                        float* filt_mem[2], float* mem_preemph)

 {
     float buf[30 + LP_FILTER_ORDER_16k];
     float *tmpbuf = buf + LP_FILTER_ORDER_16k;
     float s;
     int i;
 
     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
         filt_mem[0][i] = iir_mem[i] * ff_pow_0_5[i];
 
     memcpy(tmpbuf - LP_FILTER_ORDER_16k, mem_preemph,
            LP_FILTER_ORDER_16k*sizeof(*buf));
 
     ff_celp_lp_synthesis_filterf(tmpbuf, filt_mem[1], synth, 30,
                                  LP_FILTER_ORDER_16k);
 
     memcpy(synth - LP_FILTER_ORDER_16k, mem_preemph,
            LP_FILTER_ORDER_16k * sizeof(*synth));
 

     ff_celp_lp_synthesis_filterf(synth, filt_mem[0], synth, 30,

                                  LP_FILTER_ORDER_16k);
 

     memcpy(out_data + 30 - LP_FILTER_ORDER_16k,
            synth    + 30 - LP_FILTER_ORDER_16k,
            LP_FILTER_ORDER_16k * sizeof(*synth));
 
     ff_celp_lp_synthesis_filterf(out_data + 30, filt_mem[0],
                                  synth + 30, 2 * L_SUBFR_16k - 30,
                                  LP_FILTER_ORDER_16k);
 
 
     memcpy(mem_preemph, out_data + 2*L_SUBFR_16k - LP_FILTER_ORDER_16k,

            LP_FILTER_ORDER_16k * sizeof(*synth));
 
     FFSWAP(float *, filt_mem[0], filt_mem[1]);
     for (i = 0, s = 0; i < 30; i++, s += 1.0/30)

         out_data[i] = tmpbuf[i] + s * (synth[i] - tmpbuf[i]);

 }
 
 /**
  * Floating point version of ff_acelp_lp_decode().
  */
 static void acelp_lp_decodef(float *lp_1st, float *lp_2nd,
                              const double *lsp_2nd, const double *lsp_prev)
 {
     double lsp_1st[LP_FILTER_ORDER_16k];
     int i;
 
     /* LSP values for first subframe (3.2.5 of G.729, Equation 24) */
     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
         lsp_1st[i] = (lsp_2nd[i] + lsp_prev[i]) * 0.5;
 
     ff_acelp_lspd2lpc(lsp_1st, lp_1st, LP_FILTER_ORDER_16k >> 1);
 
     /* LSP values for second subframe (3.2.5 of G.729) */
     ff_acelp_lspd2lpc(lsp_2nd, lp_2nd, LP_FILTER_ORDER_16k >> 1);
 }
 
 /**
  * Floating point version of ff_acelp_decode_gain_code().
  */
 static float acelp_decode_gain_codef(float gain_corr_factor, const float *fc_v,
                                      float mr_energy, const float *quant_energy,
                                      const float *ma_prediction_coeff,
                                      int subframe_size, int ma_pred_order)
 {

     mr_energy += avpriv_scalarproduct_float_c(quant_energy, ma_prediction_coeff,
                                               ma_pred_order);

 
     mr_energy = gain_corr_factor * exp(M_LN10 / 20. * mr_energy) /

         sqrt((0.01 + avpriv_scalarproduct_float_c(fc_v, fc_v, subframe_size)));

     return mr_energy;
 }
 
 #define DIVIDE_BY_3(x) ((x) * 10923 >> 15)
 
 void ff_sipr_decode_frame_16k(SiprContext *ctx, SiprParameters *params,
                               float *out_data)
 {
     int frame_size = SUBFRAME_COUNT_16k * L_SUBFR_16k;
     float *synth = ctx->synth_buf + LP_FILTER_ORDER_16k;
     float lsf_new[LP_FILTER_ORDER_16k];
     double lsp_new[LP_FILTER_ORDER_16k];
     float Az[2][LP_FILTER_ORDER_16k];
     float fixed_vector[L_SUBFR_16k];
     float pitch_fac, gain_code;
 
     int i;
     int pitch_delay_3x;
 
     float *excitation = ctx->excitation + 292;
 
     lsf_decode_fp_16k(ctx->lsf_history, lsf_new, params->vq_indexes,
                       params->ma_pred_switch);
 
     ff_set_min_dist_lsf(lsf_new, LSFQ_DIFF_MIN / 2, LP_FILTER_ORDER_16k);
 
     lsf2lsp(lsf_new, lsp_new);
 
     acelp_lp_decodef(Az[0], Az[1], lsp_new, ctx->lsp_history_16k);
 
     memcpy(ctx->lsp_history_16k, lsp_new, LP_FILTER_ORDER_16k * sizeof(double));
 
     memcpy(synth - LP_FILTER_ORDER_16k, ctx->synth,
            LP_FILTER_ORDER_16k * sizeof(*synth));
 
     for (i = 0; i < SUBFRAME_COUNT_16k; i++) {
         int i_subfr = i * L_SUBFR_16k;
         AMRFixed f;
         float gain_corr_factor;
         int pitch_delay_int;
         int pitch_delay_frac;
 
         if (!i) {
             pitch_delay_3x = dec_delay3_1st(params->pitch_delay[i]);
         } else
             pitch_delay_3x = dec_delay3_2nd(params->pitch_delay[i],
                                             PITCH_MIN, PITCH_MAX,
                                             ctx->pitch_lag_prev);
 
         pitch_fac = gain_pitch_cb_16k[params->gp_index[i]];
         f.pitch_fac = FFMIN(pitch_fac, 1.0);
         f.pitch_lag = DIVIDE_BY_3(pitch_delay_3x+1);
         ctx->pitch_lag_prev = f.pitch_lag;
 
         pitch_delay_int  = DIVIDE_BY_3(pitch_delay_3x + 2);
         pitch_delay_frac = pitch_delay_3x + 2 - 3*pitch_delay_int;
 
         ff_acelp_interpolatef(&excitation[i_subfr],
                               &excitation[i_subfr] - pitch_delay_int + 1,
                               sinc_win, 3, pitch_delay_frac + 1,
                               LP_FILTER_ORDER, L_SUBFR_16k);
 
 
         memset(fixed_vector, 0, sizeof(fixed_vector));
 
         ff_decode_10_pulses_35bits(params->fc_indexes[i], &f,
                                    ff_fc_4pulses_8bits_tracks_13, 5, 4);
 
         ff_set_fixed_vector(fixed_vector, &f, 1.0, L_SUBFR_16k);
 
         gain_corr_factor = gain_cb_16k[params->gc_index[i]];
         gain_code = gain_corr_factor *
             acelp_decode_gain_codef(sqrt(L_SUBFR_16k), fixed_vector,
                                     19.0 - 15.0/(0.05*M_LN10/M_LN2),
                                     pred_16k, ctx->energy_history,
                                     L_SUBFR_16k, 2);
 
         ctx->energy_history[1] = ctx->energy_history[0];
         ctx->energy_history[0] = 20.0 * log10f(gain_corr_factor);
 
         ff_weighted_vector_sumf(&excitation[i_subfr], &excitation[i_subfr],
                                 fixed_vector, pitch_fac,
                                 gain_code, L_SUBFR_16k);
 
         ff_celp_lp_synthesis_filterf(synth + i_subfr, Az[i],
                                      &excitation[i_subfr], L_SUBFR_16k,
                                      LP_FILTER_ORDER_16k);
 
     }
     memcpy(ctx->synth, synth + frame_size - LP_FILTER_ORDER_16k,
            LP_FILTER_ORDER_16k * sizeof(*synth));
 
     memmove(ctx->excitation, ctx->excitation + 2 * L_SUBFR_16k,
             (L_INTERPOL+PITCH_MAX) * sizeof(float));
 

     postfilter(out_data, synth, ctx->iir_mem, ctx->filt_mem, ctx->mem_preemph);

 
     memcpy(ctx->iir_mem, Az[1], LP_FILTER_ORDER_16k * sizeof(float));
 }
 

 av_cold void ff_sipr_init_16k(SiprContext *ctx)

 {
     int i;
 
     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
         ctx->lsp_history_16k[i] = cos((i + 1) * M_PI/(LP_FILTER_ORDER_16k + 1));
 
     ctx->filt_mem[0] = ctx->filt_buf[0];
     ctx->filt_mem[1] = ctx->filt_buf[1];
 
     ctx->pitch_lag_prev = 180;
 }