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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 FFmpeg.
8  *
9  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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/attributes.h"
28 #include "libavutil/common.h"
29 #include "libavutil/float_dsp.h"
30 #include "libavutil/mathematics.h"
31 #include "lsp.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  */
lsf2lsp(const float * lsf,double * lsp)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 
dequant(float * out,const int * idx,const float * const cbs[])53 static void dequant(float *out, const int *idx, const float * const 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 
lsf_decode_fp_16k(float * lsf_history,float * isp_new,const int * parm,int ma_pred)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 
dec_delay3_1st(int index)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 
dec_delay3_2nd(int index,int pit_min,int pit_max,int pitch_lag_prev)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 
postfilter(float * out_data,float * synth,float * iir_mem,float * filt_mem[2],float * mem_preemph)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  */
acelp_lp_decodef(float * lp_1st,float * lp_2nd,const double * lsp_2nd,const double * lsp_prev)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  */
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)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 
ff_sipr_decode_frame_16k(SiprContext * ctx,SiprParameters * params,float * out_data)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 
ff_sipr_init_16k(SiprContext * ctx)271 av_cold 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 }
283