libavcodec/sipr16k.c

   1 /*
   2  * SIPR decoder for the 16k mode
   3  *
   4  * Copyright (c) 2008 Vladimir Voroshilov
   5  * Copyright (c) 2009 Vitor Sessak
   6  *
   7  * This file is part of Libav.
   8  *
   9  * Libav is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * Libav is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with Libav; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #include <math.h>
  25
  26 #include "sipr.h"
  27 #include "libavutil/mathematics.h"
  28 #include "lsp.h"
  29 #include "celp_math.h"
  30 #include "acelp_vectors.h"
  31 #include "acelp_pitch_delay.h"
  32 #include "acelp_filters.h"
  33 #include "celp_filters.h"
  34
  35 #include "sipr16kdata.h"
  36
  37 /**
  38  * Convert an lsf vector into an lsp vector.
  39  *
  40  * @param lsf               input lsf vector
  41  * @param lsp               output lsp vector
  42  */
  43 static void lsf2lsp(const float *lsf, double *lsp)
  44 {
  45     int i;
  46
  47     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
  48         lsp[i] = cosf(lsf[i]);
  49 }
  50
  51 static void dequant(float *out, const int *idx, const float *cbs[])
  52 {
  53     int i;
  54
  55     for (i = 0; i < 4; i++)
  56         memcpy(out + 3*i, cbs[i] + 3*idx[i], 3*sizeof(float));
  57
  58     memcpy(out + 12, cbs[4] + 4*idx[4], 4*sizeof(float));
  59 }
  60
  61 static void lsf_decode_fp_16k(float* lsf_history, float* isp_new,
  62                               const int* parm, int ma_pred)
  63 {
  64     int i;
  65     float isp_q[LP_FILTER_ORDER_16k];
  66
  67     dequant(isp_q, parm, lsf_codebooks_16k);
  68
  69     for (i = 0; i < LP_FILTER_ORDER_16k; i++) {
  70         isp_new[i] = (1 - qu[ma_pred]) * isp_q[i]
  71                     +     qu[ma_pred]  * lsf_history[i]
  72                     + mean_lsf_16k[i];
  73     }
  74
  75     memcpy(lsf_history, isp_q, LP_FILTER_ORDER_16k * sizeof(float));
  76 }
  77
  78 static int dec_delay3_1st(int index)
  79 {
  80     if (index < 390) {
  81         return index + 88;
  82     } else
  83         return 3 * index - 690;
  84 }
  85
  86 static int dec_delay3_2nd(int index, int pit_min, int pit_max,
  87                           int pitch_lag_prev)
  88 {
  89     if (index < 62) {
  90         int pitch_delay_min = av_clip(pitch_lag_prev - 10,
  91                                       pit_min, pit_max - 19);
  92         return 3 * pitch_delay_min + index - 2;
  93     } else
  94         return 3 * pitch_lag_prev;
  95 }
  96
  97 static void postfilter(float *out_data, float* synth, float* iir_mem,
  98                        float* filt_mem[2], float* mem_preemph)
  99 {
 100     float buf[30 + LP_FILTER_ORDER_16k];
 101     float *tmpbuf = buf + LP_FILTER_ORDER_16k;
 102     float s;
 103     int i;
 104
 105     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
 106         filt_mem[0][i] = iir_mem[i] * ff_pow_0_5[i];
 107
 108     memcpy(tmpbuf - LP_FILTER_ORDER_16k, mem_preemph,
 109            LP_FILTER_ORDER_16k*sizeof(*buf));
 110
 111     ff_celp_lp_synthesis_filterf(tmpbuf, filt_mem[1], synth, 30,
 112                                  LP_FILTER_ORDER_16k);
 113
 114     memcpy(synth - LP_FILTER_ORDER_16k, mem_preemph,
 115            LP_FILTER_ORDER_16k * sizeof(*synth));
 116
 117     ff_celp_lp_synthesis_filterf(synth, filt_mem[0], synth, 30,
 118                                  LP_FILTER_ORDER_16k);
 119
 120     memcpy(out_data + 30 - LP_FILTER_ORDER_16k,
 121            synth    + 30 - LP_FILTER_ORDER_16k,
 122            LP_FILTER_ORDER_16k * sizeof(*synth));
 123
 124     ff_celp_lp_synthesis_filterf(out_data + 30, filt_mem[0],
 125                                  synth + 30, 2 * L_SUBFR_16k - 30,
 126                                  LP_FILTER_ORDER_16k);
 127
 128
 129     memcpy(mem_preemph, out_data + 2*L_SUBFR_16k - LP_FILTER_ORDER_16k,
 130            LP_FILTER_ORDER_16k * sizeof(*synth));
 131
 132     FFSWAP(float *, filt_mem[0], filt_mem[1]);
 133     for (i = 0, s = 0; i < 30; i++, s += 1.0/30)
 134         out_data[i] = tmpbuf[i] + s * (synth[i] - tmpbuf[i]);
 135 }
 136
 137 /**
 138  * Floating point version of ff_acelp_lp_decode().
 139  */
 140 static void acelp_lp_decodef(float *lp_1st, float *lp_2nd,
 141                              const double *lsp_2nd, const double *lsp_prev)
 142 {
 143     double lsp_1st[LP_FILTER_ORDER_16k];
 144     int i;
 145
 146     /* LSP values for first subframe (3.2.5 of G.729, Equation 24) */
 147     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
 148         lsp_1st[i] = (lsp_2nd[i] + lsp_prev[i]) * 0.5;
 149
 150     ff_acelp_lspd2lpc(lsp_1st, lp_1st, LP_FILTER_ORDER_16k >> 1);
 151
 152     /* LSP values for second subframe (3.2.5 of G.729) */
 153     ff_acelp_lspd2lpc(lsp_2nd, lp_2nd, LP_FILTER_ORDER_16k >> 1);
 154 }
 155
 156 /**
 157  * Floating point version of ff_acelp_decode_gain_code().
 158  */
 159 static float acelp_decode_gain_codef(float gain_corr_factor, const float *fc_v,
 160                                      float mr_energy, const float *quant_energy,
 161                                      const float *ma_prediction_coeff,
 162                                      int subframe_size, int ma_pred_order)
 163 {
 164     mr_energy +=
 165         ff_dot_productf(quant_energy, ma_prediction_coeff, ma_pred_order);
 166
 167     mr_energy = gain_corr_factor * exp(M_LN10 / 20. * mr_energy) /
 168         sqrt((0.01 + ff_dot_productf(fc_v, fc_v, subframe_size)));
 169     return mr_energy;
 170 }
 171
 172 #define DIVIDE_BY_3(x) ((x) * 10923 >> 15)
 173
 174 void ff_sipr_decode_frame_16k(SiprContext *ctx, SiprParameters *params,
 175                               float *out_data)
 176 {
 177     int frame_size = SUBFRAME_COUNT_16k * L_SUBFR_16k;
 178     float *synth = ctx->synth_buf + LP_FILTER_ORDER_16k;
 179     float lsf_new[LP_FILTER_ORDER_16k];
 180     double lsp_new[LP_FILTER_ORDER_16k];
 181     float Az[2][LP_FILTER_ORDER_16k];
 182     float fixed_vector[L_SUBFR_16k];
 183     float pitch_fac, gain_code;
 184
 185     int i;
 186     int pitch_delay_3x;
 187
 188     float *excitation = ctx->excitation + 292;
 189
 190     lsf_decode_fp_16k(ctx->lsf_history, lsf_new, params->vq_indexes,
 191                       params->ma_pred_switch);
 192
 193     ff_set_min_dist_lsf(lsf_new, LSFQ_DIFF_MIN / 2, LP_FILTER_ORDER_16k);
 194
 195     lsf2lsp(lsf_new, lsp_new);
 196
 197     acelp_lp_decodef(Az[0], Az[1], lsp_new, ctx->lsp_history_16k);
 198
 199     memcpy(ctx->lsp_history_16k, lsp_new, LP_FILTER_ORDER_16k * sizeof(double));
 200
 201     memcpy(synth - LP_FILTER_ORDER_16k, ctx->synth,
 202            LP_FILTER_ORDER_16k * sizeof(*synth));
 203
 204     for (i = 0; i < SUBFRAME_COUNT_16k; i++) {
 205         int i_subfr = i * L_SUBFR_16k;
 206         AMRFixed f;
 207         float gain_corr_factor;
 208         int pitch_delay_int;
 209         int pitch_delay_frac;
 210
 211         if (!i) {
 212             pitch_delay_3x = dec_delay3_1st(params->pitch_delay[i]);
 213         } else
 214             pitch_delay_3x = dec_delay3_2nd(params->pitch_delay[i],
 215                                             PITCH_MIN, PITCH_MAX,
 216                                             ctx->pitch_lag_prev);
 217
 218         pitch_fac = gain_pitch_cb_16k[params->gp_index[i]];
 219         f.pitch_fac = FFMIN(pitch_fac, 1.0);
 220         f.pitch_lag = DIVIDE_BY_3(pitch_delay_3x+1);
 221         ctx->pitch_lag_prev = f.pitch_lag;
 222
 223         pitch_delay_int  = DIVIDE_BY_3(pitch_delay_3x + 2);
 224         pitch_delay_frac = pitch_delay_3x + 2 - 3*pitch_delay_int;
 225
 226         ff_acelp_interpolatef(&excitation[i_subfr],
 227                               &excitation[i_subfr] - pitch_delay_int + 1,
 228                               sinc_win, 3, pitch_delay_frac + 1,
 229                               LP_FILTER_ORDER, L_SUBFR_16k);
 230
 231
 232         memset(fixed_vector, 0, sizeof(fixed_vector));
 233
 234         ff_decode_10_pulses_35bits(params->fc_indexes[i], &f,
 235                                    ff_fc_4pulses_8bits_tracks_13, 5, 4);
 236
 237         ff_set_fixed_vector(fixed_vector, &f, 1.0, L_SUBFR_16k);
 238
 239         gain_corr_factor = gain_cb_16k[params->gc_index[i]];
 240         gain_code = gain_corr_factor *
 241             acelp_decode_gain_codef(sqrt(L_SUBFR_16k), fixed_vector,
 242                                     19.0 - 15.0/(0.05*M_LN10/M_LN2),
 243                                     pred_16k, ctx->energy_history,
 244                                     L_SUBFR_16k, 2);
 245
 246         ctx->energy_history[1] = ctx->energy_history[0];
 247         ctx->energy_history[0] = 20.0 * log10f(gain_corr_factor);
 248
 249         ff_weighted_vector_sumf(&excitation[i_subfr], &excitation[i_subfr],
 250                                 fixed_vector, pitch_fac,
 251                                 gain_code, L_SUBFR_16k);
 252
 253         ff_celp_lp_synthesis_filterf(synth + i_subfr, Az[i],
 254                                      &excitation[i_subfr], L_SUBFR_16k,
 255                                      LP_FILTER_ORDER_16k);
 256
 257     }
 258     memcpy(ctx->synth, synth + frame_size - LP_FILTER_ORDER_16k,
 259            LP_FILTER_ORDER_16k * sizeof(*synth));
 260
 261     memmove(ctx->excitation, ctx->excitation + 2 * L_SUBFR_16k,
 262             (L_INTERPOL+PITCH_MAX) * sizeof(float));
 263
 264     postfilter(out_data, synth, ctx->iir_mem, ctx->filt_mem, ctx->mem_preemph);
 265
 266     memcpy(ctx->iir_mem, Az[1], LP_FILTER_ORDER_16k * sizeof(float));
 267 }
 268
 269 void ff_sipr_init_16k(SiprContext *ctx)
 270 {
 271     int i;
 272
 273     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
 274         ctx->lsp_history_16k[i] = cos((i + 1) * M_PI/(LP_FILTER_ORDER_16k + 1));
 275
 276     ctx->filt_mem[0] = ctx->filt_buf[0];
 277     ctx->filt_mem[1] = ctx->filt_buf[1];
 278
 279     ctx->pitch_lag_prev = 180;
 280 }