git.sesse.net Git - ffmpeg/blob - 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/common.h"
  28 #include "libavutil/mathematics.h"
  29 #include "lsp.h"
  30 #include "celp_math.h"
  31 #include "acelp_vectors.h"
  32 #include "acelp_pitch_delay.h"
  33 #include "acelp_filters.h"
  34 #include "celp_filters.h"
  35
  36 #include "sipr16kdata.h"
  37
  38 /**
  39  * Convert an lsf vector into an lsp vector.
  40  *
  41  * @param lsf               input lsf vector
  42  * @param lsp               output lsp vector
  43  */
  44 static void lsf2lsp(const float *lsf, double *lsp)
  45 {
  46     int i;
  47
  48     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
  49         lsp[i] = cosf(lsf[i]);
  50 }
  51
  52 static void dequant(float *out, const int *idx, const float *cbs[])
  53 {
  54     int i;
  55
  56     for (i = 0; i < 4; i++)
  57         memcpy(out + 3*i, cbs[i] + 3*idx[i], 3*sizeof(float));
  58
  59     memcpy(out + 12, cbs[4] + 4*idx[4], 4*sizeof(float));
  60 }
  61
  62 static void lsf_decode_fp_16k(float* lsf_history, float* isp_new,
  63                               const int* parm, int ma_pred)
  64 {
  65     int i;
  66     float isp_q[LP_FILTER_ORDER_16k];
  67
  68     dequant(isp_q, parm, lsf_codebooks_16k);
  69
  70     for (i = 0; i < LP_FILTER_ORDER_16k; i++) {
  71         isp_new[i] = (1 - qu[ma_pred]) * isp_q[i]
  72                     +     qu[ma_pred]  * lsf_history[i]
  73                     + mean_lsf_16k[i];
  74     }
  75
  76     memcpy(lsf_history, isp_q, LP_FILTER_ORDER_16k * sizeof(float));
  77 }
  78
  79 static int dec_delay3_1st(int index)
  80 {
  81     if (index < 390) {
  82         return index + 88;
  83     } else
  84         return 3 * index - 690;
  85 }
  86
  87 static int dec_delay3_2nd(int index, int pit_min, int pit_max,
  88                           int pitch_lag_prev)
  89 {
  90     if (index < 62) {
  91         int pitch_delay_min = av_clip(pitch_lag_prev - 10,
  92                                       pit_min, pit_max - 19);
  93         return 3 * pitch_delay_min + index - 2;
  94     } else
  95         return 3 * pitch_lag_prev;
  96 }
  97
  98 static void postfilter(float *out_data, float* synth, float* iir_mem,
  99                        float* filt_mem[2], float* mem_preemph)
 100 {
 101     float buf[30 + LP_FILTER_ORDER_16k];
 102     float *tmpbuf = buf + LP_FILTER_ORDER_16k;
 103     float s;
 104     int i;
 105
 106     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
 107         filt_mem[0][i] = iir_mem[i] * ff_pow_0_5[i];
 108
 109     memcpy(tmpbuf - LP_FILTER_ORDER_16k, mem_preemph,
 110            LP_FILTER_ORDER_16k*sizeof(*buf));
 111
 112     ff_celp_lp_synthesis_filterf(tmpbuf, filt_mem[1], synth, 30,
 113                                  LP_FILTER_ORDER_16k);
 114
 115     memcpy(synth - LP_FILTER_ORDER_16k, mem_preemph,
 116            LP_FILTER_ORDER_16k * sizeof(*synth));
 117
 118     ff_celp_lp_synthesis_filterf(synth, filt_mem[0], synth, 30,
 119                                  LP_FILTER_ORDER_16k);
 120
 121     memcpy(out_data + 30 - LP_FILTER_ORDER_16k,
 122            synth    + 30 - LP_FILTER_ORDER_16k,
 123            LP_FILTER_ORDER_16k * sizeof(*synth));
 124
 125     ff_celp_lp_synthesis_filterf(out_data + 30, filt_mem[0],
 126                                  synth + 30, 2 * L_SUBFR_16k - 30,
 127                                  LP_FILTER_ORDER_16k);
 128
 129
 130     memcpy(mem_preemph, out_data + 2*L_SUBFR_16k - LP_FILTER_ORDER_16k,
 131            LP_FILTER_ORDER_16k * sizeof(*synth));
 132
 133     FFSWAP(float *, filt_mem[0], filt_mem[1]);
 134     for (i = 0, s = 0; i < 30; i++, s += 1.0/30)
 135         out_data[i] = tmpbuf[i] + s * (synth[i] - tmpbuf[i]);
 136 }
 137
 138 /**
 139  * Floating point version of ff_acelp_lp_decode().
 140  */
 141 static void acelp_lp_decodef(float *lp_1st, float *lp_2nd,
 142                              const double *lsp_2nd, const double *lsp_prev)
 143 {
 144     double lsp_1st[LP_FILTER_ORDER_16k];
 145     int i;
 146
 147     /* LSP values for first subframe (3.2.5 of G.729, Equation 24) */
 148     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
 149         lsp_1st[i] = (lsp_2nd[i] + lsp_prev[i]) * 0.5;
 150
 151     ff_acelp_lspd2lpc(lsp_1st, lp_1st, LP_FILTER_ORDER_16k >> 1);
 152
 153     /* LSP values for second subframe (3.2.5 of G.729) */
 154     ff_acelp_lspd2lpc(lsp_2nd, lp_2nd, LP_FILTER_ORDER_16k >> 1);
 155 }
 156
 157 /**
 158  * Floating point version of ff_acelp_decode_gain_code().
 159  */
 160 static float acelp_decode_gain_codef(float gain_corr_factor, const float *fc_v,
 161                                      float mr_energy, const float *quant_energy,
 162                                      const float *ma_prediction_coeff,
 163                                      int subframe_size, int ma_pred_order)
 164 {
 165     mr_energy +=
 166         ff_dot_productf(quant_energy, ma_prediction_coeff, ma_pred_order);
 167
 168     mr_energy = gain_corr_factor * exp(M_LN10 / 20. * mr_energy) /
 169         sqrt((0.01 + ff_dot_productf(fc_v, fc_v, subframe_size)));
 170     return mr_energy;
 171 }
 172
 173 #define DIVIDE_BY_3(x) ((x) * 10923 >> 15)
 174
 175 void ff_sipr_decode_frame_16k(SiprContext *ctx, SiprParameters *params,
 176                               float *out_data)
 177 {
 178     int frame_size = SUBFRAME_COUNT_16k * L_SUBFR_16k;
 179     float *synth = ctx->synth_buf + LP_FILTER_ORDER_16k;
 180     float lsf_new[LP_FILTER_ORDER_16k];
 181     double lsp_new[LP_FILTER_ORDER_16k];
 182     float Az[2][LP_FILTER_ORDER_16k];
 183     float fixed_vector[L_SUBFR_16k];
 184     float pitch_fac, gain_code;
 185
 186     int i;
 187     int pitch_delay_3x;
 188
 189     float *excitation = ctx->excitation + 292;
 190
 191     lsf_decode_fp_16k(ctx->lsf_history, lsf_new, params->vq_indexes,
 192                       params->ma_pred_switch);
 193
 194     ff_set_min_dist_lsf(lsf_new, LSFQ_DIFF_MIN / 2, LP_FILTER_ORDER_16k);
 195
 196     lsf2lsp(lsf_new, lsp_new);
 197
 198     acelp_lp_decodef(Az[0], Az[1], lsp_new, ctx->lsp_history_16k);
 199
 200     memcpy(ctx->lsp_history_16k, lsp_new, LP_FILTER_ORDER_16k * sizeof(double));
 201
 202     memcpy(synth - LP_FILTER_ORDER_16k, ctx->synth,
 203            LP_FILTER_ORDER_16k * sizeof(*synth));
 204
 205     for (i = 0; i < SUBFRAME_COUNT_16k; i++) {
 206         int i_subfr = i * L_SUBFR_16k;
 207         AMRFixed f;
 208         float gain_corr_factor;
 209         int pitch_delay_int;
 210         int pitch_delay_frac;
 211
 212         if (!i) {
 213             pitch_delay_3x = dec_delay3_1st(params->pitch_delay[i]);
 214         } else
 215             pitch_delay_3x = dec_delay3_2nd(params->pitch_delay[i],
 216                                             PITCH_MIN, PITCH_MAX,
 217                                             ctx->pitch_lag_prev);
 218
 219         pitch_fac = gain_pitch_cb_16k[params->gp_index[i]];
 220         f.pitch_fac = FFMIN(pitch_fac, 1.0);
 221         f.pitch_lag = DIVIDE_BY_3(pitch_delay_3x+1);
 222         ctx->pitch_lag_prev = f.pitch_lag;
 223
 224         pitch_delay_int  = DIVIDE_BY_3(pitch_delay_3x + 2);
 225         pitch_delay_frac = pitch_delay_3x + 2 - 3*pitch_delay_int;
 226
 227         ff_acelp_interpolatef(&excitation[i_subfr],
 228                               &excitation[i_subfr] - pitch_delay_int + 1,
 229                               sinc_win, 3, pitch_delay_frac + 1,
 230                               LP_FILTER_ORDER, L_SUBFR_16k);
 231
 232
 233         memset(fixed_vector, 0, sizeof(fixed_vector));
 234
 235         ff_decode_10_pulses_35bits(params->fc_indexes[i], &f,
 236                                    ff_fc_4pulses_8bits_tracks_13, 5, 4);
 237
 238         ff_set_fixed_vector(fixed_vector, &f, 1.0, L_SUBFR_16k);
 239
 240         gain_corr_factor = gain_cb_16k[params->gc_index[i]];
 241         gain_code = gain_corr_factor *
 242             acelp_decode_gain_codef(sqrt(L_SUBFR_16k), fixed_vector,
 243                                     19.0 - 15.0/(0.05*M_LN10/M_LN2),
 244                                     pred_16k, ctx->energy_history,
 245                                     L_SUBFR_16k, 2);
 246
 247         ctx->energy_history[1] = ctx->energy_history[0];
 248         ctx->energy_history[0] = 20.0 * log10f(gain_corr_factor);
 249
 250         ff_weighted_vector_sumf(&excitation[i_subfr], &excitation[i_subfr],
 251                                 fixed_vector, pitch_fac,
 252                                 gain_code, L_SUBFR_16k);
 253
 254         ff_celp_lp_synthesis_filterf(synth + i_subfr, Az[i],
 255                                      &excitation[i_subfr], L_SUBFR_16k,
 256                                      LP_FILTER_ORDER_16k);
 257
 258     }
 259     memcpy(ctx->synth, synth + frame_size - LP_FILTER_ORDER_16k,
 260            LP_FILTER_ORDER_16k * sizeof(*synth));
 261
 262     memmove(ctx->excitation, ctx->excitation + 2 * L_SUBFR_16k,
 263             (L_INTERPOL+PITCH_MAX) * sizeof(float));
 264
 265     postfilter(out_data, synth, ctx->iir_mem, ctx->filt_mem, ctx->mem_preemph);
 266
 267     memcpy(ctx->iir_mem, Az[1], LP_FILTER_ORDER_16k * sizeof(float));
 268 }
 269
 270 void ff_sipr_init_16k(SiprContext *ctx)
 271 {
 272     int i;
 273
 274     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
 275         ctx->lsp_history_16k[i] = cos((i + 1) * M_PI/(LP_FILTER_ORDER_16k + 1));
 276
 277     ctx->filt_mem[0] = ctx->filt_buf[0];
 278     ctx->filt_mem[1] = ctx->filt_buf[1];
 279
 280     ctx->pitch_lag_prev = 180;
 281 }