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/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 */
43static 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
51static 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
61static 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
78static int dec_delay3_1st(int index)
79{
80    if (index < 390) {
81        return index + 88;
82    } else
83        return 3 * index - 690;
84}
85
86static 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
97static 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 */
140static 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 */
159static 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
174void 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
269void 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}
281