xref: /third_party/ffmpeg/libavcodec/sipr16k.c (revision cabdff1a)
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 */
45static 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
53static 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
63static 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
80static int dec_delay3_1st(int index)
81{
82    if (index < 390) {
83        return index + 88;
84    } else
85        return 3 * index - 690;
86}
87
88static 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
99static 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 */
142static 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 */
161static 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
176void 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
271av_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