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/float_dsp.h"
  29 #include "libavutil/mathematics.h"
  30 #include "lsp.h"
  31 #include "celp_filters.h"
  32 #include "acelp_vectors.h"
  33 #include "acelp_pitch_delay.h"
  34 #include "acelp_filters.h"
  35 #include "celp_filters.h"
  36
  37 #include "sipr16kdata.h"
  38
  39 /**
  40  * Convert an lsf vector into an lsp vector.
  41  *
  42  * @param lsf               input lsf vector
  43  * @param lsp               output lsp vector
  44  */
  45 static void lsf2lsp(const float *lsf, double *lsp)
  46 {
  47     int i;
  48
  49     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
  50         lsp[i] = cosf(lsf[i]);
  51 }
  52
  53 static void dequant(float *out, const int *idx, const float *cbs[])
  54 {
  55     int i;
  56
  57     for (i = 0; i < 4; i++)
  58         memcpy(out + 3*i, cbs[i] + 3*idx[i], 3*sizeof(float));
  59
  60     memcpy(out + 12, cbs[4] + 4*idx[4], 4*sizeof(float));
  61 }
  62
  63 static void lsf_decode_fp_16k(float* lsf_history, float* isp_new,
  64                               const int* parm, int ma_pred)
  65 {
  66     int i;
  67     float isp_q[LP_FILTER_ORDER_16k];
  68
  69     dequant(isp_q, parm, lsf_codebooks_16k);
  70
  71     for (i = 0; i < LP_FILTER_ORDER_16k; i++) {
  72         isp_new[i] = (1 - qu[ma_pred]) * isp_q[i]
  73                     +     qu[ma_pred]  * lsf_history[i]
  74                     + mean_lsf_16k[i];
  75     }
  76
  77     memcpy(lsf_history, isp_q, LP_FILTER_ORDER_16k * sizeof(float));
  78 }
  79
  80 static int dec_delay3_1st(int index)
  81 {
  82     if (index < 390) {
  83         return index + 88;
  84     } else
  85         return 3 * index - 690;
  86 }
  87
  88 static int dec_delay3_2nd(int index, int pit_min, int pit_max,
  89                           int pitch_lag_prev)
  90 {
  91     if (index < 62) {
  92         int pitch_delay_min = av_clip(pitch_lag_prev - 10,
  93                                       pit_min, pit_max - 19);
  94         return 3 * pitch_delay_min + index - 2;
  95     } else
  96         return 3 * pitch_lag_prev;
  97 }
  98
  99 static void postfilter(float *out_data, float* synth, float* iir_mem,
 100                        float* filt_mem[2], float* mem_preemph)
 101 {
 102     float buf[30 + LP_FILTER_ORDER_16k];
 103     float *tmpbuf = buf + LP_FILTER_ORDER_16k;
 104     float s;
 105     int i;
 106
 107     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
 108         filt_mem[0][i] = iir_mem[i] * ff_pow_0_5[i];
 109
 110     memcpy(tmpbuf - LP_FILTER_ORDER_16k, mem_preemph,
 111            LP_FILTER_ORDER_16k*sizeof(*buf));
 112
 113     ff_celp_lp_synthesis_filterf(tmpbuf, filt_mem[1], synth, 30,
 114                                  LP_FILTER_ORDER_16k);
 115
 116     memcpy(synth - LP_FILTER_ORDER_16k, mem_preemph,
 117            LP_FILTER_ORDER_16k * sizeof(*synth));
 118
 119     ff_celp_lp_synthesis_filterf(synth, filt_mem[0], synth, 30,
 120                                  LP_FILTER_ORDER_16k);
 121
 122     memcpy(out_data + 30 - LP_FILTER_ORDER_16k,
 123            synth    + 30 - LP_FILTER_ORDER_16k,
 124            LP_FILTER_ORDER_16k * sizeof(*synth));
 125
 126     ff_celp_lp_synthesis_filterf(out_data + 30, filt_mem[0],
 127                                  synth + 30, 2 * L_SUBFR_16k - 30,
 128                                  LP_FILTER_ORDER_16k);
 129
 130
 131     memcpy(mem_preemph, out_data + 2*L_SUBFR_16k - LP_FILTER_ORDER_16k,
 132            LP_FILTER_ORDER_16k * sizeof(*synth));
 133
 134     FFSWAP(float *, filt_mem[0], filt_mem[1]);
 135     for (i = 0, s = 0; i < 30; i++, s += 1.0/30)
 136         out_data[i] = tmpbuf[i] + s * (synth[i] - tmpbuf[i]);
 137 }
 138
 139 /**
 140  * Floating point version of ff_acelp_lp_decode().
 141  */
 142 static void acelp_lp_decodef(float *lp_1st, float *lp_2nd,
 143                              const double *lsp_2nd, const double *lsp_prev)
 144 {
 145     double lsp_1st[LP_FILTER_ORDER_16k];
 146     int i;
 147
 148     /* LSP values for first subframe (3.2.5 of G.729, Equation 24) */
 149     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
 150         lsp_1st[i] = (lsp_2nd[i] + lsp_prev[i]) * 0.5;
 151
 152     ff_acelp_lspd2lpc(lsp_1st, lp_1st, LP_FILTER_ORDER_16k >> 1);
 153
 154     /* LSP values for second subframe (3.2.5 of G.729) */
 155     ff_acelp_lspd2lpc(lsp_2nd, lp_2nd, LP_FILTER_ORDER_16k >> 1);
 156 }
 157
 158 /**
 159  * Floating point version of ff_acelp_decode_gain_code().
 160  */
 161 static float acelp_decode_gain_codef(float gain_corr_factor, const float *fc_v,
 162                                      float mr_energy, const float *quant_energy,
 163                                      const float *ma_prediction_coeff,
 164                                      int subframe_size, int ma_pred_order)
 165 {
 166     mr_energy += avpriv_scalarproduct_float_c(quant_energy, ma_prediction_coeff,
 167                                               ma_pred_order);
 168
 169     mr_energy = gain_corr_factor * exp(M_LN10 / 20. * mr_energy) /
 170         sqrt((0.01 + avpriv_scalarproduct_float_c(fc_v, fc_v, subframe_size)));
 171     return mr_energy;
 172 }
 173
 174 #define DIVIDE_BY_3(x) ((x) * 10923 >> 15)
 175
 176 void ff_sipr_decode_frame_16k(SiprContext *ctx, SiprParameters *params,
 177                               float *out_data)
 178 {
 179     int frame_size = SUBFRAME_COUNT_16k * L_SUBFR_16k;
 180     float *synth = ctx->synth_buf + LP_FILTER_ORDER_16k;
 181     float lsf_new[LP_FILTER_ORDER_16k];
 182     double lsp_new[LP_FILTER_ORDER_16k];
 183     float Az[2][LP_FILTER_ORDER_16k];
 184     float fixed_vector[L_SUBFR_16k];
 185     float pitch_fac, gain_code;
 186
 187     int i;
 188     int pitch_delay_3x;
 189
 190     float *excitation = ctx->excitation + 292;
 191
 192     lsf_decode_fp_16k(ctx->lsf_history, lsf_new, params->vq_indexes,
 193                       params->ma_pred_switch);
 194
 195     ff_set_min_dist_lsf(lsf_new, LSFQ_DIFF_MIN / 2, LP_FILTER_ORDER_16k);
 196
 197     lsf2lsp(lsf_new, lsp_new);
 198
 199     acelp_lp_decodef(Az[0], Az[1], lsp_new, ctx->lsp_history_16k);
 200
 201     memcpy(ctx->lsp_history_16k, lsp_new, LP_FILTER_ORDER_16k * sizeof(double));
 202
 203     memcpy(synth - LP_FILTER_ORDER_16k, ctx->synth,
 204            LP_FILTER_ORDER_16k * sizeof(*synth));
 205
 206     for (i = 0; i < SUBFRAME_COUNT_16k; i++) {
 207         int i_subfr = i * L_SUBFR_16k;
 208         AMRFixed f;
 209         float gain_corr_factor;
 210         int pitch_delay_int;
 211         int pitch_delay_frac;
 212
 213         if (!i) {
 214             pitch_delay_3x = dec_delay3_1st(params->pitch_delay[i]);
 215         } else
 216             pitch_delay_3x = dec_delay3_2nd(params->pitch_delay[i],
 217                                             PITCH_MIN, PITCH_MAX,
 218                                             ctx->pitch_lag_prev);
 219
 220         pitch_fac = gain_pitch_cb_16k[params->gp_index[i]];
 221         f.pitch_fac = FFMIN(pitch_fac, 1.0);
 222         f.pitch_lag = DIVIDE_BY_3(pitch_delay_3x+1);
 223         ctx->pitch_lag_prev = f.pitch_lag;
 224
 225         pitch_delay_int  = DIVIDE_BY_3(pitch_delay_3x + 2);
 226         pitch_delay_frac = pitch_delay_3x + 2 - 3*pitch_delay_int;
 227
 228         ff_acelp_interpolatef(&excitation[i_subfr],
 229                               &excitation[i_subfr] - pitch_delay_int + 1,
 230                               sinc_win, 3, pitch_delay_frac + 1,
 231                               LP_FILTER_ORDER, L_SUBFR_16k);
 232
 233
 234         memset(fixed_vector, 0, sizeof(fixed_vector));
 235
 236         ff_decode_10_pulses_35bits(params->fc_indexes[i], &f,
 237                                    ff_fc_4pulses_8bits_tracks_13, 5, 4);
 238
 239         ff_set_fixed_vector(fixed_vector, &f, 1.0, L_SUBFR_16k);
 240
 241         gain_corr_factor = gain_cb_16k[params->gc_index[i]];
 242         gain_code = gain_corr_factor *
 243             acelp_decode_gain_codef(sqrt(L_SUBFR_16k), fixed_vector,
 244                                     19.0 - 15.0/(0.05*M_LN10/M_LN2),
 245                                     pred_16k, ctx->energy_history,
 246                                     L_SUBFR_16k, 2);
 247
 248         ctx->energy_history[1] = ctx->energy_history[0];
 249         ctx->energy_history[0] = 20.0 * log10f(gain_corr_factor);
 250
 251         ff_weighted_vector_sumf(&excitation[i_subfr], &excitation[i_subfr],
 252                                 fixed_vector, pitch_fac,
 253                                 gain_code, L_SUBFR_16k);
 254
 255         ff_celp_lp_synthesis_filterf(synth + i_subfr, Az[i],
 256                                      &excitation[i_subfr], L_SUBFR_16k,
 257                                      LP_FILTER_ORDER_16k);
 258
 259     }
 260     memcpy(ctx->synth, synth + frame_size - LP_FILTER_ORDER_16k,
 261            LP_FILTER_ORDER_16k * sizeof(*synth));
 262
 263     memmove(ctx->excitation, ctx->excitation + 2 * L_SUBFR_16k,
 264             (L_INTERPOL+PITCH_MAX) * sizeof(float));
 265
 266     postfilter(out_data, synth, ctx->iir_mem, ctx->filt_mem, ctx->mem_preemph);
 267
 268     memcpy(ctx->iir_mem, Az[1], LP_FILTER_ORDER_16k * sizeof(float));
 269 }
 270
 271 void ff_sipr_init_16k(SiprContext *ctx)
 272 {
 273     int i;
 274
 275     for (i = 0; i < LP_FILTER_ORDER_16k; i++)
 276         ctx->lsp_history_16k[i] = cos((i + 1) * M_PI/(LP_FILTER_ORDER_16k + 1));
 277
 278     ctx->filt_mem[0] = ctx->filt_buf[0];
 279     ctx->filt_mem[1] = ctx->filt_buf[1];
 280
 281     ctx->pitch_lag_prev = 180;
 282 }