1 /*
2  * Copyright (c) 2013, The WebRTC project authors. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions are
6  * met:
7  *
8  *   * Redistributions of source code must retain the above copyright
9  *     notice, this list of conditions and the following disclaimer.
10  *
11  *   * Redistributions in binary form must reproduce the above copyright
12  *     notice, this list of conditions and the following disclaimer in
13  *     the documentation and/or other materials provided with the
14  *     distribution.
15  *
16  *   * Neither the name of Google nor the names of its contributors may
17  *     be used to endorse or promote products derived from this software
18  *     without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include "libavutil/channel_layout.h"
34 #include "avcodec.h"
35 #include "codec_internal.h"
36 #include "internal.h"
37 #include "get_bits.h"
38 #include "ilbcdata.h"
39 
40 #define LPC_N_20MS            1
41 #define LPC_N_30MS            2
42 #define LPC_N_MAX             2
43 #define LSF_NSPLIT            3
44 #define NASUB_MAX             4
45 #define LPC_FILTERORDER       10
46 #define NSUB_MAX              6
47 #define SUBL                  40
48 
49 #define ST_MEM_L_TBL          85
50 #define MEM_LF_TBL            147
51 #define STATE_SHORT_LEN_20MS  57
52 #define STATE_SHORT_LEN_30MS  58
53 
54 #define BLOCKL_MAX            240
55 #define CB_MEML               147
56 #define CB_NSTAGES            3
57 #define CB_HALFFILTERLEN      4
58 #define CB_FILTERLEN          8
59 
60 #define ENH_NBLOCKS_TOT 8
61 #define ENH_BLOCKL     80
62 #define ENH_BUFL     (ENH_NBLOCKS_TOT)*ENH_BLOCKL
63 #define ENH_BUFL_FILTEROVERHEAD  3
64 #define BLOCKL_MAX      240
65 #define NSUB_20MS         4
66 #define NSUB_30MS         6
67 #define NSUB_MAX          6
68 #define NASUB_20MS        2
69 #define NASUB_30MS        4
70 #define NASUB_MAX         4
71 #define STATE_LEN        80
72 #define STATE_SHORT_LEN_30MS  58
73 #define STATE_SHORT_LEN_20MS  57
74 
75 #define SPL_MUL_16_16(a, b) ((int32_t) (((int16_t)(a)) * ((int16_t)(b))))
76 #define SPL_MUL_16_16_RSFT(a, b, c) (SPL_MUL_16_16(a, b) >> (c))
77 
78 typedef struct ILBCFrame {
79     int16_t  lsf[LSF_NSPLIT*LPC_N_MAX];
80     int16_t  cb_index[CB_NSTAGES*(NASUB_MAX + 1)];
81     int16_t  gain_index[CB_NSTAGES*(NASUB_MAX + 1)];
82     int16_t  ifm;
83     int16_t  state_first;
84     int16_t  idx[STATE_SHORT_LEN_30MS];
85     int16_t  firstbits;
86     int16_t  start;
87 } ILBCFrame;
88 
89 typedef struct ILBCContext {
90     AVClass         *class;
91     int              enhancer;
92 
93     int              mode;
94     GetBitContext    gb;
95     ILBCFrame        frame;
96 
97     int              prev_enh_pl;
98     int              consPLICount;
99     int              last_lag;
100     int              state_short_len;
101     int              lpc_n;
102     int16_t          nasub;
103     int16_t          nsub;
104     int              block_samples;
105     int16_t          no_of_words;
106     int16_t          no_of_bytes;
107     int16_t          lsfdeq[LPC_FILTERORDER*LPC_N_MAX];
108     int16_t          lsfold[LPC_FILTERORDER];
109     int16_t          syntMem[LPC_FILTERORDER];
110     int16_t          lsfdeqold[LPC_FILTERORDER];
111     int16_t          weightdenum[(LPC_FILTERORDER + 1) * NSUB_MAX];
112     int16_t          syntdenum[NSUB_MAX * (LPC_FILTERORDER + 1)];
113     int16_t          old_syntdenum[NSUB_MAX * (LPC_FILTERORDER + 1)];
114     int16_t          enh_buf[ENH_BUFL+ENH_BUFL_FILTEROVERHEAD];
115     int16_t          enh_period[ENH_NBLOCKS_TOT];
116     int16_t          prevResidual[NSUB_MAX*SUBL];
117     int16_t          decresidual[BLOCKL_MAX];
118     int16_t          plc_residual[BLOCKL_MAX + LPC_FILTERORDER];
119     int16_t          seed;
120     int16_t          prevPLI;
121     int16_t          prevScale;
122     int16_t          prevLag;
123     int16_t          per_square;
124     int16_t          prev_lpc[LPC_FILTERORDER + 1];
125     int16_t          plc_lpc[LPC_FILTERORDER + 1];
126     int16_t          hpimemx[2];
127     int16_t          hpimemy[4];
128 } ILBCContext;
129 
unpack_frame(ILBCContext *s)130 static int unpack_frame(ILBCContext *s)
131 {
132     ILBCFrame *frame = &s->frame;
133     GetBitContext *gb = &s->gb;
134     int j;
135 
136     frame->lsf[0] = get_bits(gb, 6);
137     frame->lsf[1] = get_bits(gb, 7);
138     frame->lsf[2] = get_bits(gb, 7);
139 
140     if (s->mode == 20) {
141         frame->start          = get_bits(gb, 2);
142         frame->state_first    = get_bits1(gb);
143         frame->ifm            = get_bits(gb, 6);
144         frame->cb_index[0]    = get_bits(gb, 6) << 1;
145         frame->gain_index[0]  = get_bits(gb, 2) << 3;
146         frame->gain_index[1]  = get_bits1(gb) << 3;
147         frame->cb_index[3]    = get_bits(gb, 7) << 1;
148         frame->gain_index[3]  = get_bits1(gb) << 4;
149         frame->gain_index[4]  = get_bits1(gb) << 3;
150         frame->gain_index[6]  = get_bits1(gb) << 4;
151     } else {
152         frame->lsf[3]         = get_bits(gb, 6);
153         frame->lsf[4]         = get_bits(gb, 7);
154         frame->lsf[5]         = get_bits(gb, 7);
155         frame->start          = get_bits(gb, 3);
156         frame->state_first    = get_bits1(gb);
157         frame->ifm            = get_bits(gb, 6);
158         frame->cb_index[0]    = get_bits(gb, 4) << 3;
159         frame->gain_index[0]  = get_bits1(gb) << 4;
160         frame->gain_index[1]  = get_bits1(gb) << 3;
161         frame->cb_index[3]    = get_bits(gb, 6) << 2;
162         frame->gain_index[3]  = get_bits1(gb) << 4;
163         frame->gain_index[4]  = get_bits1(gb) << 3;
164     }
165 
166     for (j = 0; j < 48; j++)
167         frame->idx[j] = get_bits1(gb) << 2;
168 
169     if (s->mode == 20) {
170         for (; j < 57; j++)
171             frame->idx[j] = get_bits1(gb) << 2;
172 
173         frame->gain_index[1] |= get_bits1(gb) << 2;
174         frame->gain_index[3] |= get_bits(gb, 2) << 2;
175         frame->gain_index[4] |= get_bits1(gb) << 2;
176         frame->gain_index[6] |= get_bits1(gb) << 3;
177         frame->gain_index[7]  = get_bits(gb, 2) << 2;
178     } else {
179         for (; j < 58; j++)
180             frame->idx[j] = get_bits1(gb) << 2;
181 
182         frame->cb_index[0]    |= get_bits(gb, 2) << 1;
183         frame->gain_index[0]  |= get_bits1(gb) << 3;
184         frame->gain_index[1]  |= get_bits1(gb) << 2;
185         frame->cb_index[3]    |= get_bits1(gb) << 1;
186         frame->cb_index[6]     = get_bits1(gb) << 7;
187         frame->cb_index[6]    |= get_bits(gb, 6) << 1;
188         frame->cb_index[9]     = get_bits(gb, 7) << 1;
189         frame->cb_index[12]    = get_bits(gb, 3) << 5;
190         frame->cb_index[12]   |= get_bits(gb, 4) << 1;
191         frame->gain_index[3]  |= get_bits(gb, 2) << 2;
192         frame->gain_index[4]  |= get_bits(gb, 2) << 1;
193         frame->gain_index[6]   = get_bits(gb, 2) << 3;
194         frame->gain_index[7]   = get_bits(gb, 2) << 2;
195         frame->gain_index[9]   = get_bits1(gb) << 4;
196         frame->gain_index[10]  = get_bits1(gb) << 3;
197         frame->gain_index[12]  = get_bits1(gb) << 4;
198         frame->gain_index[13]  = get_bits1(gb) << 3;
199     }
200 
201     for (j = 0; j < 56; j++)
202         frame->idx[j] |= get_bits(gb, 2);
203 
204     if (s->mode == 20) {
205         frame->idx[56]        |= get_bits(gb, 2);
206         frame->cb_index[0]    |= get_bits1(gb);
207         frame->cb_index[1]     = get_bits(gb, 7);
208         frame->cb_index[2]     = get_bits(gb, 6) << 1;
209         frame->cb_index[2]    |= get_bits1(gb);
210         frame->gain_index[0]  |= get_bits(gb, 3);
211         frame->gain_index[1]  |= get_bits(gb, 2);
212         frame->gain_index[2]   = get_bits(gb, 3);
213         frame->cb_index[3]    |= get_bits1(gb);
214         frame->cb_index[4]     = get_bits(gb, 6) << 1;
215         frame->cb_index[4]    |= get_bits1(gb);
216         frame->cb_index[5]     = get_bits(gb, 7);
217         frame->cb_index[6]     = get_bits(gb, 8);
218         frame->cb_index[7]     = get_bits(gb, 8);
219         frame->cb_index[8]     = get_bits(gb, 8);
220         frame->gain_index[3]  |= get_bits(gb, 2);
221         frame->gain_index[4]  |= get_bits(gb, 2);
222         frame->gain_index[5]   = get_bits(gb, 3);
223         frame->gain_index[6]  |= get_bits(gb, 3);
224         frame->gain_index[7]  |= get_bits(gb, 2);
225         frame->gain_index[8]   = get_bits(gb, 3);
226     } else {
227         frame->idx[56]        |= get_bits(gb, 2);
228         frame->idx[57]        |= get_bits(gb, 2);
229         frame->cb_index[0]    |= get_bits1(gb);
230         frame->cb_index[1]     = get_bits(gb, 7);
231         frame->cb_index[2]     = get_bits(gb, 4) << 3;
232         frame->cb_index[2]    |= get_bits(gb, 3);
233         frame->gain_index[0]  |= get_bits(gb, 3);
234         frame->gain_index[1]  |= get_bits(gb, 2);
235         frame->gain_index[2]   = get_bits(gb, 3);
236         frame->cb_index[3]    |= get_bits1(gb);
237         frame->cb_index[4]     = get_bits(gb, 4) << 3;
238         frame->cb_index[4]    |= get_bits(gb, 3);
239         frame->cb_index[5]     = get_bits(gb, 7);
240         frame->cb_index[6]    |= get_bits1(gb);
241         frame->cb_index[7]     = get_bits(gb, 5) << 3;
242         frame->cb_index[7]    |= get_bits(gb, 3);
243         frame->cb_index[8]     = get_bits(gb, 8);
244         frame->cb_index[9]    |= get_bits1(gb);
245         frame->cb_index[10]    = get_bits(gb, 4) << 4;
246         frame->cb_index[10]   |= get_bits(gb, 4);
247         frame->cb_index[11]    = get_bits(gb, 8);
248         frame->cb_index[12]   |= get_bits1(gb);
249         frame->cb_index[13]    = get_bits(gb, 3) << 5;
250         frame->cb_index[13]   |= get_bits(gb, 5);
251         frame->cb_index[14]    = get_bits(gb, 8);
252         frame->gain_index[3]  |= get_bits(gb, 2);
253         frame->gain_index[4]  |= get_bits1(gb);
254         frame->gain_index[5]   = get_bits(gb, 3);
255         frame->gain_index[6]  |= get_bits(gb, 3);
256         frame->gain_index[7]  |= get_bits(gb, 2);
257         frame->gain_index[8]   = get_bits(gb, 3);
258         frame->gain_index[9]  |= get_bits(gb, 4);
259         frame->gain_index[10] |= get_bits1(gb) << 2;
260         frame->gain_index[10] |= get_bits(gb, 2);
261         frame->gain_index[11]  = get_bits(gb, 3);
262         frame->gain_index[12] |= get_bits(gb, 4);
263         frame->gain_index[13] |= get_bits(gb, 3);
264         frame->gain_index[14]  = get_bits(gb, 3);
265     }
266 
267     return get_bits1(gb);
268 }
269 
index_conv(int16_t *index)270 static void index_conv(int16_t *index)
271 {
272     int k;
273 
274     for (k = 4; k < 6; k++) {
275         if (index[k] >= 44 && index[k] < 108) {
276             index[k] += 64;
277         } else if (index[k] >= 108 && index[k] < 128) {
278             index[k] += 128;
279         }
280     }
281 }
282 
lsf_dequantization(int16_t *lsfdeq, int16_t *index, int16_t lpc_n)283 static void lsf_dequantization(int16_t *lsfdeq, int16_t *index, int16_t lpc_n)
284 {
285     int i, j, pos = 0, cb_pos = 0;
286 
287     for (i = 0; i < LSF_NSPLIT; i++) {
288         for (j = 0; j < lsf_dim_codebook[i]; j++) {
289             lsfdeq[pos + j] = lsf_codebook[cb_pos + index[i] * lsf_dim_codebook[i] + j];
290         }
291 
292         pos    += lsf_dim_codebook[i];
293         cb_pos += lsf_size_codebook[i] * lsf_dim_codebook[i];
294     }
295 
296     if (lpc_n > 1) {
297         pos = 0;
298         cb_pos = 0;
299         for (i = 0; i < LSF_NSPLIT; i++) {
300             for (j = 0; j < lsf_dim_codebook[i]; j++) {
301                 lsfdeq[LPC_FILTERORDER + pos + j] = lsf_codebook[cb_pos +
302                     index[LSF_NSPLIT + i] * lsf_dim_codebook[i] + j];
303             }
304 
305             pos    += lsf_dim_codebook[i];
306             cb_pos += lsf_size_codebook[i] * lsf_dim_codebook[i];
307         }
308     }
309 }
310 
lsf_check_stability(int16_t *lsf, int dim, int nb_vectors)311 static void lsf_check_stability(int16_t *lsf, int dim, int nb_vectors)
312 {
313     for (int n = 0; n < 2; n++) {
314         for (int m = 0; m < nb_vectors; m++) {
315             for (int k = 0; k < dim - 1; k++) {
316                 int i = m * dim + k;
317 
318                 if ((lsf[i + 1] - lsf[i]) < 319) {
319                     if (lsf[i + 1] < lsf[i]) {
320                         lsf[i + 1] = lsf[i] + 160;
321                         lsf[i]     = lsf[i + 1] - 160;
322                     } else {
323                         lsf[i]     -= 160;
324                         lsf[i + 1] += 160;
325                     }
326                 }
327 
328                 lsf[i] = av_clip(lsf[i], 82, 25723);
329             }
330         }
331     }
332 }
333 
lsf_interpolate(int16_t *out, int16_t *in1, int16_t *in2, int16_t coef, int size)334 static void lsf_interpolate(int16_t *out, int16_t *in1,
335                             int16_t *in2, int16_t coef,
336                             int size)
337 {
338     int invcoef = 16384 - coef, i;
339 
340     for (i = 0; i < size; i++)
341         out[i] = (coef * in1[i] + invcoef * in2[i] + 8192) >> 14;
342 }
343 
lsf2lsp(int16_t *lsf, int16_t *lsp, int order)344 static void lsf2lsp(int16_t *lsf, int16_t *lsp, int order)
345 {
346     int16_t diff, freq;
347     int32_t tmp;
348     int i, k;
349 
350     for (i = 0; i < order; i++) {
351         freq = (lsf[i] * 20861) >> 15;
352         /* 20861: 1.0/(2.0*PI) in Q17 */
353         /*
354            Upper 8 bits give the index k and
355            Lower 8 bits give the difference, which needs
356            to be approximated linearly
357          */
358         k = FFMIN(freq >> 8, 63);
359         diff = freq & 0xFF;
360 
361         /* Calculate linear approximation */
362         tmp = cos_derivative_tbl[k] * diff;
363         lsp[i] = cos_tbl[k] + (tmp >> 12);
364     }
365 }
366 
get_lsp_poly(int16_t *lsp, int32_t *f)367 static void get_lsp_poly(int16_t *lsp, int32_t *f)
368 {
369     int16_t high, low;
370     int i, j, k, l;
371     int32_t tmp;
372 
373     f[0] = 16777216;
374     f[1] = lsp[0] * -1024;
375 
376     for (i = 2, k = 2, l = 2; i <= 5; i++, k += 2) {
377         f[l] = f[l - 2];
378 
379         for (j = i; j > 1; j--, l--) {
380             high = f[l - 1] >> 16;
381             low = (f[l - 1] - (high * (1 << 16))) >> 1;
382 
383             tmp = ((high * lsp[k]) * 4) + (((low * lsp[k]) >> 15) * 4);
384 
385             f[l] += f[l - 2];
386             f[l] -= (unsigned)tmp;
387         }
388 
389         f[l] -= lsp[k] * (1 << 10);
390         l += i;
391     }
392 }
393 
lsf2poly(int16_t *a, int16_t *lsf)394 static void lsf2poly(int16_t *a, int16_t *lsf)
395 {
396     int32_t f[2][6];
397     int16_t lsp[10];
398     int32_t tmp;
399     int i;
400 
401     lsf2lsp(lsf, lsp, LPC_FILTERORDER);
402 
403     get_lsp_poly(&lsp[0], f[0]);
404     get_lsp_poly(&lsp[1], f[1]);
405 
406     for (i = 5; i > 0; i--) {
407         f[0][i] += (unsigned)f[0][i - 1];
408         f[1][i] -= (unsigned)f[1][i - 1];
409     }
410 
411     a[0] = 4096;
412     for (i = 5; i > 0; i--) {
413         tmp = f[0][6 - i] + (unsigned)f[1][6 - i] + 4096;
414         a[6 - i] = tmp >> 13;
415 
416         tmp = f[0][6 - i] - (unsigned)f[1][6 - i] + 4096;
417         a[5 + i] = tmp >> 13;
418     }
419 }
420 
lsp_interpolate2polydec(int16_t *a, int16_t *lsf1, int16_t *lsf2, int coef, int length)421 static void lsp_interpolate2polydec(int16_t *a, int16_t *lsf1,
422                                    int16_t *lsf2, int coef, int length)
423 {
424     int16_t lsftmp[LPC_FILTERORDER];
425 
426     lsf_interpolate(lsftmp, lsf1, lsf2, coef, length);
427     lsf2poly(a, lsftmp);
428 }
429 
bw_expand(int16_t *out, const int16_t *in, const int16_t *coef, int length)430 static void bw_expand(int16_t *out, const int16_t *in, const int16_t *coef, int length)
431 {
432     int i;
433 
434     out[0] = in[0];
435     for (i = 1; i < length; i++)
436         out[i] = (coef[i] * in[i] + 16384) >> 15;
437 }
438 
lsp_interpolate(int16_t *syntdenum, int16_t *weightdenum, int16_t *lsfdeq, int16_t length, ILBCContext *s)439 static void lsp_interpolate(int16_t *syntdenum, int16_t *weightdenum,
440                             int16_t *lsfdeq, int16_t length,
441                             ILBCContext *s)
442 {
443     int16_t lp[LPC_FILTERORDER + 1], *lsfdeq2;
444     int i, pos, lp_length;
445 
446     lsfdeq2 = lsfdeq + length;
447     lp_length = length + 1;
448 
449     if (s->mode == 30) {
450         lsp_interpolate2polydec(lp, (*s).lsfdeqold, lsfdeq, lsf_weight_30ms[0], length);
451         memcpy(syntdenum, lp, lp_length * 2);
452         bw_expand(weightdenum, lp, kLpcChirpSyntDenum, lp_length);
453 
454         pos = lp_length;
455         for (i = 1; i < 6; i++) {
456             lsp_interpolate2polydec(lp, lsfdeq, lsfdeq2,
457                                                  lsf_weight_30ms[i],
458                                                  length);
459             memcpy(syntdenum + pos, lp, lp_length * 2);
460             bw_expand(weightdenum + pos, lp, kLpcChirpSyntDenum, lp_length);
461             pos += lp_length;
462         }
463     } else {
464         pos = 0;
465         for (i = 0; i < s->nsub; i++) {
466             lsp_interpolate2polydec(lp, s->lsfdeqold, lsfdeq,
467                                     lsf_weight_20ms[i], length);
468             memcpy(syntdenum + pos, lp, lp_length * 2);
469             bw_expand(weightdenum + pos, lp, kLpcChirpSyntDenum, lp_length);
470             pos += lp_length;
471         }
472     }
473 
474     if (s->mode == 30) {
475         memcpy(s->lsfdeqold, lsfdeq2, length * 2);
476     } else {
477         memcpy(s->lsfdeqold, lsfdeq, length * 2);
478     }
479 }
480 
filter_mafq12(int16_t *in_ptr, int16_t *out_ptr, int16_t *B, int16_t B_length, int16_t length)481 static void filter_mafq12(int16_t *in_ptr, int16_t *out_ptr,
482                           int16_t *B, int16_t B_length,
483                           int16_t length)
484 {
485     int o, i, j;
486 
487     for (i = 0; i < length; i++) {
488         const int16_t *b_ptr = &B[0];
489         const int16_t *x_ptr = &in_ptr[i];
490 
491         o = 0;
492         for (j = 0; j < B_length; j++)
493             o += b_ptr[j] * *x_ptr--;
494 
495         o = av_clip(o, -134217728, 134215679);
496 
497         out_ptr[i] = ((o + 2048) >> 12);
498     }
499 }
500 
filter_arfq12(const int16_t *data_in, int16_t *data_out, const int16_t *coefficients, int coefficients_length, int data_length)501 static void filter_arfq12(const int16_t *data_in,
502                           int16_t *data_out,
503                           const int16_t *coefficients,
504                           int coefficients_length,
505                           int data_length)
506 {
507     int i, j;
508 
509     for (i = 0; i < data_length; i++) {
510         int output = 0, sum = 0;
511 
512         for (j = coefficients_length - 1; j > 0; j--) {
513             sum += (unsigned)(coefficients[j] * data_out[i - j]);
514         }
515 
516         output = coefficients[0] * data_in[i] - (unsigned)sum;
517         output = av_clip(output, -134217728, 134215679);
518 
519         data_out[i] = (output + 2048) >> 12;
520     }
521 }
522 
state_construct(int16_t ifm, int16_t *idx, int16_t *synt_denum, int16_t *Out_fix, int16_t len)523 static void state_construct(int16_t ifm, int16_t *idx,
524                            int16_t *synt_denum, int16_t *Out_fix,
525                            int16_t len)
526 {
527     int k;
528     int16_t maxVal;
529     int16_t *tmp1, *tmp2, *tmp3;
530     /* Stack based */
531     int16_t numerator[1 + LPC_FILTERORDER];
532     int16_t sampleValVec[2 * STATE_SHORT_LEN_30MS + LPC_FILTERORDER];
533     int16_t sampleMaVec[2 * STATE_SHORT_LEN_30MS + LPC_FILTERORDER];
534     int16_t *sampleVal = &sampleValVec[LPC_FILTERORDER];
535     int16_t *sampleMa = &sampleMaVec[LPC_FILTERORDER];
536     int16_t *sampleAr = &sampleValVec[LPC_FILTERORDER];
537 
538     /* initialization of coefficients */
539 
540     for (k = 0; k < LPC_FILTERORDER + 1; k++) {
541         numerator[k] = synt_denum[LPC_FILTERORDER - k];
542     }
543 
544     /* decoding of the maximum value */
545 
546     maxVal = frg_quant_mod[ifm];
547 
548     /* decoding of the sample values */
549     tmp1 = sampleVal;
550     tmp2 = &idx[len - 1];
551 
552     if (ifm < 37) {
553         for (k = 0; k < len; k++) {
554             /*the shifting is due to the Q13 in sq4_fixQ13[i], also the adding of 2097152 (= 0.5 << 22)
555                maxVal is in Q8 and result is in Q(-1) */
556             (*tmp1) = (int16_t) ((SPL_MUL_16_16(maxVal, ilbc_state[(*tmp2)]) + 2097152) >> 22);
557             tmp1++;
558             tmp2--;
559         }
560     } else if (ifm < 59) {
561         for (k = 0; k < len; k++) {
562             /*the shifting is due to the Q13 in sq4_fixQ13[i], also the adding of 262144 (= 0.5 << 19)
563                maxVal is in Q5 and result is in Q(-1) */
564             (*tmp1) = (int16_t) ((SPL_MUL_16_16(maxVal, ilbc_state[(*tmp2)]) + 262144) >> 19);
565             tmp1++;
566             tmp2--;
567         }
568     } else {
569         for (k = 0; k < len; k++) {
570             /*the shifting is due to the Q13 in sq4_fixQ13[i], also the adding of 65536 (= 0.5 << 17)
571                maxVal is in Q3 and result is in Q(-1) */
572             (*tmp1) = (int16_t) ((SPL_MUL_16_16(maxVal, ilbc_state[(*tmp2)]) + 65536) >> 17);
573             tmp1++;
574             tmp2--;
575         }
576     }
577 
578     /* Set the rest of the data to zero */
579     memset(&sampleVal[len], 0, len * 2);
580 
581     /* circular convolution with all-pass filter */
582 
583     /* Set the state to zero */
584     memset(sampleValVec, 0, LPC_FILTERORDER * 2);
585 
586     /* Run MA filter + AR filter */
587     filter_mafq12(sampleVal, sampleMa, numerator, LPC_FILTERORDER + 1, len + LPC_FILTERORDER);
588     memset(&sampleMa[len + LPC_FILTERORDER], 0, (len - LPC_FILTERORDER) * 2);
589     filter_arfq12(sampleMa, sampleAr, synt_denum, LPC_FILTERORDER + 1, 2 * len);
590 
591     tmp1 = &sampleAr[len - 1];
592     tmp2 = &sampleAr[2 * len - 1];
593     tmp3 = Out_fix;
594     for (k = 0; k < len; k++) {
595         (*tmp3) = (*tmp1) + (*tmp2);
596         tmp1--;
597         tmp2--;
598         tmp3++;
599     }
600 }
601 
gain_dequantization(int index, int max_in, int stage)602 static int16_t gain_dequantization(int index, int max_in, int stage)
603 {
604     int16_t scale = FFMAX(1638, FFABS(max_in));
605 
606     return ((scale * ilbc_gain[stage][index]) + 8192) >> 14;
607 }
608 
vector_rmultiplication(int16_t *out, const int16_t *in, const int16_t *win, int length, int shift)609 static void vector_rmultiplication(int16_t *out, const int16_t *in,
610                                    const int16_t *win,
611                                    int length, int shift)
612 {
613     for (int i = 0; i < length; i++)
614         out[i] = (in[i] * win[-i]) >> shift;
615 }
616 
vector_multiplication(int16_t *out, const int16_t *in, const int16_t *win, int length, int shift)617 static void vector_multiplication(int16_t *out, const int16_t *in,
618                                   const int16_t *win, int length,
619                                   int shift)
620 {
621     for (int i = 0; i < length; i++)
622         out[i] = (in[i] * win[i]) >> shift;
623 }
624 
add_vector_and_shift(int16_t *out, const int16_t *in1, const int16_t *in2, int length, int shift)625 static void add_vector_and_shift(int16_t *out, const int16_t *in1,
626                                  const int16_t *in2, int length,
627                                  int shift)
628 {
629     for (int i = 0; i < length; i++)
630         out[i] = (in1[i] + in2[i]) >> shift;
631 }
632 
create_augmented_vector(int index, int16_t *buffer, int16_t *cbVec)633 static void create_augmented_vector(int index, int16_t *buffer, int16_t *cbVec)
634 {
635     int16_t cbVecTmp[4];
636     int interpolation_length = FFMIN(4, index);
637     int16_t ilow = index - interpolation_length;
638 
639     memcpy(cbVec, buffer - index, index * 2);
640 
641     vector_multiplication(&cbVec[ilow], buffer - index - interpolation_length, alpha, interpolation_length, 15);
642     vector_rmultiplication(cbVecTmp, buffer - interpolation_length, &alpha[interpolation_length - 1], interpolation_length, 15);
643     add_vector_and_shift(&cbVec[ilow], &cbVec[ilow], cbVecTmp, interpolation_length, 0);
644 
645     memcpy(cbVec + index, buffer - index, FFMIN(SUBL - index, index) * sizeof(*cbVec));
646 }
647 
get_codebook(int16_t * cbvec, int16_t * mem, int16_t index, int16_t lMem, int16_t cbveclen )648 static void get_codebook(int16_t * cbvec,   /* (o) Constructed codebook vector */
649                      int16_t * mem,     /* (i) Codebook buffer */
650                      int16_t index,     /* (i) Codebook index */
651                      int16_t lMem,      /* (i) Length of codebook buffer */
652                      int16_t cbveclen   /* (i) Codebook vector length */
653 )
654 {
655     int16_t k, base_size;
656     int16_t lag;
657     /* Stack based */
658     int16_t tempbuff2[SUBL + 5];
659 
660     /* Determine size of codebook sections */
661     base_size = lMem - cbveclen + 1;
662 
663     if (cbveclen == SUBL) {
664         base_size += cbveclen / 2;
665     }
666 
667     /* No filter -> First codebook section */
668     if (index < lMem - cbveclen + 1) {
669         /* first non-interpolated vectors */
670 
671         k = index + cbveclen;
672         /* get vector */
673         memcpy(cbvec, mem + lMem - k, cbveclen * 2);
674     } else if (index < base_size) {
675 
676         /* Calculate lag */
677 
678         k = (int16_t) SPL_MUL_16_16(2, (index - (lMem - cbveclen + 1))) + cbveclen;
679 
680         lag = k / 2;
681 
682         create_augmented_vector(lag, mem + lMem, cbvec);
683     } else {
684         int16_t memIndTest;
685 
686         /* first non-interpolated vectors */
687 
688         if (index - base_size < lMem - cbveclen + 1) {
689 
690             /* Set up filter memory, stuff zeros outside memory buffer */
691 
692             memIndTest = lMem - (index - base_size + cbveclen);
693 
694             memset(mem - CB_HALFFILTERLEN, 0, CB_HALFFILTERLEN * 2);
695             memset(mem + lMem, 0, CB_HALFFILTERLEN * 2);
696 
697             /* do filtering to get the codebook vector */
698 
699             filter_mafq12(&mem[memIndTest + 4], cbvec, (int16_t *) kCbFiltersRev, CB_FILTERLEN, cbveclen);
700         } else {
701             /* interpolated vectors */
702             /* Stuff zeros outside memory buffer  */
703             memIndTest = lMem - cbveclen - CB_FILTERLEN;
704             memset(mem + lMem, 0, CB_HALFFILTERLEN * 2);
705 
706             /* do filtering */
707             filter_mafq12(&mem[memIndTest + 7], tempbuff2, (int16_t *) kCbFiltersRev, CB_FILTERLEN, (int16_t) (cbveclen + 5));
708 
709             /* Calculate lag index */
710             lag = (cbveclen << 1) - 20 + index - base_size - lMem - 1;
711 
712             create_augmented_vector(lag, tempbuff2 + SUBL + 5, cbvec);
713         }
714     }
715 }
716 
construct_vector( int16_t *decvector, int16_t *index, int16_t *gain_index, int16_t *mem, int16_t lMem, int16_t veclen)717 static void construct_vector (
718     int16_t *decvector,   /* (o) Decoded vector */
719     int16_t *index,       /* (i) Codebook indices */
720     int16_t *gain_index,  /* (i) Gain quantization indices */
721     int16_t *mem,         /* (i) Buffer for codevector construction */
722     int16_t lMem,         /* (i) Length of buffer */
723     int16_t veclen)
724 {
725     int16_t gain[CB_NSTAGES];
726     int16_t cbvec0[SUBL];
727     int16_t cbvec1[SUBL];
728     int16_t cbvec2[SUBL];
729     unsigned a32;
730     int16_t *gainPtr;
731     int j;
732 
733     /* gain de-quantization */
734 
735     gain[0] = gain_dequantization(gain_index[0], 16384, 0);
736     gain[1] = gain_dequantization(gain_index[1], gain[0], 1);
737     gain[2] = gain_dequantization(gain_index[2], gain[1], 2);
738 
739     /* codebook vector construction and construction of total vector */
740 
741     /* Stack based */
742     get_codebook(cbvec0, mem, index[0], lMem, veclen);
743     get_codebook(cbvec1, mem, index[1], lMem, veclen);
744     get_codebook(cbvec2, mem, index[2], lMem, veclen);
745 
746     gainPtr = &gain[0];
747     for (j = 0; j < veclen; j++) {
748         a32 = SPL_MUL_16_16(*gainPtr++, cbvec0[j]);
749         a32 += SPL_MUL_16_16(*gainPtr++, cbvec1[j]);
750         a32 += SPL_MUL_16_16(*gainPtr, cbvec2[j]);
751         gainPtr -= 2;
752         decvector[j] = (int)(a32 + 8192) >> 14;
753     }
754 }
755 
reverse_memcpy(int16_t *dest, int16_t *source, int length)756 static void reverse_memcpy(int16_t *dest, int16_t *source, int length)
757 {
758     int16_t* destPtr = dest;
759     int16_t* sourcePtr = source;
760     int j;
761 
762     for (j = 0; j < length; j++)
763         *destPtr-- = *sourcePtr++;
764 }
765 
decode_residual(ILBCContext *s, ILBCFrame *encbits, int16_t *decresidual, int16_t *syntdenum)766 static void decode_residual(ILBCContext *s,
767                             ILBCFrame *encbits,
768                             int16_t *decresidual,
769                             int16_t *syntdenum)
770 {
771     int16_t meml_gotten, Nfor, Nback, diff, start_pos;
772     int16_t subcount, subframe;
773     int16_t *reverseDecresidual = s->enh_buf;        /* Reversed decoded data, used for decoding backwards in time (reuse memory in state) */
774     int16_t *memVec = s->prevResidual;
775     int16_t *mem = &memVec[CB_HALFFILTERLEN];   /* Memory for codebook */
776 
777     diff = STATE_LEN - s->state_short_len;
778 
779     if (encbits->state_first == 1) {
780         start_pos = (encbits->start - 1) * SUBL;
781     } else {
782         start_pos = (encbits->start - 1) * SUBL + diff;
783     }
784 
785     /* decode scalar part of start state */
786 
787     state_construct(encbits->ifm, encbits->idx, &syntdenum[(encbits->start - 1) * (LPC_FILTERORDER + 1)], &decresidual[start_pos], s->state_short_len);
788 
789     if (encbits->state_first) { /* put adaptive part in the end */
790         /* setup memory */
791         memset(mem, 0, (int16_t) (CB_MEML - s->state_short_len) * 2);
792         memcpy(mem + CB_MEML - s->state_short_len, decresidual + start_pos, s->state_short_len * 2);
793 
794         /* construct decoded vector */
795 
796         construct_vector(&decresidual[start_pos + s->state_short_len], encbits->cb_index, encbits->gain_index, mem + CB_MEML - ST_MEM_L_TBL, ST_MEM_L_TBL, (int16_t) diff);
797 
798     } else { /* put adaptive part in the beginning */
799         /* setup memory */
800         meml_gotten = s->state_short_len;
801         reverse_memcpy(mem + CB_MEML - 1, decresidual + start_pos, meml_gotten);
802         memset(mem, 0, (int16_t) (CB_MEML - meml_gotten) * 2);
803 
804         /* construct decoded vector */
805         construct_vector(reverseDecresidual, encbits->cb_index, encbits->gain_index, mem + CB_MEML - ST_MEM_L_TBL, ST_MEM_L_TBL, diff);
806 
807         /* get decoded residual from reversed vector */
808         reverse_memcpy(&decresidual[start_pos - 1], reverseDecresidual, diff);
809     }
810 
811     /* counter for predicted subframes */
812     subcount = 1;
813 
814     /* forward prediction of subframes */
815     Nfor = s->nsub - encbits->start - 1;
816 
817     if (Nfor > 0) {
818         /* setup memory */
819         memset(mem, 0, (CB_MEML - STATE_LEN) * 2);
820         memcpy(mem + CB_MEML - STATE_LEN, decresidual + (encbits->start - 1) * SUBL, STATE_LEN * 2);
821 
822         /* loop over subframes to encode */
823         for (subframe = 0; subframe < Nfor; subframe++) {
824             /* construct decoded vector */
825             construct_vector(&decresidual[(encbits->start + 1 + subframe) * SUBL], encbits->cb_index + subcount * CB_NSTAGES, encbits->gain_index + subcount * CB_NSTAGES, mem, MEM_LF_TBL, SUBL);
826 
827             /* update memory */
828             memmove(mem, mem + SUBL, (CB_MEML - SUBL) * sizeof(*mem));
829             memcpy(mem + CB_MEML - SUBL, &decresidual[(encbits->start + 1 + subframe) * SUBL], SUBL * 2);
830 
831             subcount++;
832         }
833 
834     }
835 
836     /* backward prediction of subframes */
837     Nback = encbits->start - 1;
838 
839     if (Nback > 0) {
840         /* setup memory */
841         meml_gotten = SUBL * (s->nsub + 1 - encbits->start);
842         if (meml_gotten > CB_MEML) {
843             meml_gotten = CB_MEML;
844         }
845 
846         reverse_memcpy(mem + CB_MEML - 1, decresidual + (encbits->start - 1) * SUBL, meml_gotten);
847         memset(mem, 0, (int16_t) (CB_MEML - meml_gotten) * 2);
848 
849         /* loop over subframes to decode */
850         for (subframe = 0; subframe < Nback; subframe++) {
851             /* construct decoded vector */
852             construct_vector(&reverseDecresidual[subframe * SUBL], encbits->cb_index + subcount * CB_NSTAGES,
853                         encbits->gain_index + subcount * CB_NSTAGES, mem, MEM_LF_TBL, SUBL);
854 
855             /* update memory */
856             memmove(mem, mem + SUBL, (CB_MEML - SUBL) * sizeof(*mem));
857             memcpy(mem + CB_MEML - SUBL, &reverseDecresidual[subframe * SUBL], SUBL * 2);
858 
859             subcount++;
860         }
861 
862         /* get decoded residual from reversed vector */
863         reverse_memcpy(decresidual + SUBL * Nback - 1, reverseDecresidual, SUBL * Nback);
864     }
865 }
866 
max_abs_value_w16(const int16_t* vector, int length)867 static int16_t max_abs_value_w16(const int16_t* vector, int length)
868 {
869     int i = 0, absolute = 0, maximum = 0;
870 
871     if (vector == NULL || length <= 0) {
872         return -1;
873     }
874 
875     for (i = 0; i < length; i++) {
876         absolute = FFABS(vector[i]);
877         if (absolute > maximum)
878             maximum = absolute;
879     }
880 
881     // Guard the case for abs(-32768).
882     return FFMIN(maximum, INT16_MAX);
883 }
884 
get_size_in_bits(uint32_t n)885 static int16_t get_size_in_bits(uint32_t n)
886 {
887     int16_t bits;
888 
889     if (0xFFFF0000 & n) {
890         bits = 16;
891     } else {
892         bits = 0;
893     }
894 
895     if (0x0000FF00 & (n >> bits)) bits += 8;
896     if (0x000000F0 & (n >> bits)) bits += 4;
897     if (0x0000000C & (n >> bits)) bits += 2;
898     if (0x00000002 & (n >> bits)) bits += 1;
899     if (0x00000001 & (n >> bits)) bits += 1;
900 
901     return bits;
902 }
903 
scale_dot_product(const int16_t *v1, const int16_t *v2, int length, int scaling)904 static int32_t scale_dot_product(const int16_t *v1, const int16_t *v2, int length, int scaling)
905 {
906     int64_t sum = 0;
907 
908     for (int i = 0; i < length; i++)
909         sum += (v1[i] * v2[i]) >> scaling;
910 
911     return av_clipl_int32(sum);
912 }
913 
correlation(int32_t *corr, int32_t *ener, int16_t *buffer, int16_t lag, int16_t blen, int16_t srange, int16_t scale)914 static void correlation(int32_t *corr, int32_t *ener, int16_t *buffer,
915                         int16_t lag, int16_t blen, int16_t srange, int16_t scale)
916 {
917     int16_t *w16ptr;
918 
919     w16ptr = &buffer[blen - srange - lag];
920 
921     *corr = scale_dot_product(&buffer[blen - srange], w16ptr, srange, scale);
922     *ener = scale_dot_product(w16ptr, w16ptr, srange, scale);
923 
924     if (*ener == 0) {
925         *corr = 0;
926         *ener = 1;
927     }
928 }
929 
930 #define SPL_SHIFT_W32(x, c) (((c) >= 0) ? ((x) << (c)) : ((x) >> (-(c))))
931 
norm_w32(int32_t a)932 static int16_t norm_w32(int32_t a)
933 {
934     if (a == 0) {
935         return 0;
936     } else if (a < 0) {
937         a = ~a;
938     }
939 
940     return ff_clz(a);
941 }
942 
div_w32_w16(int32_t num, int16_t den)943 static int32_t div_w32_w16(int32_t num, int16_t den)
944 {
945     if (den != 0)
946         return num / den;
947     else
948         return 0x7FFFFFFF;
949 }
950 
do_plc(int16_t *plc_residual, int16_t *plc_lpc, int16_t PLI, int16_t *decresidual, int16_t *lpc, int16_t inlag, ILBCContext *s)951 static void do_plc(int16_t *plc_residual,      /* (o) concealed residual */
952                    int16_t *plc_lpc,           /* (o) concealed LP parameters */
953                    int16_t PLI,                /* (i) packet loss indicator
954                                                       0 - no PL, 1 = PL */
955                    int16_t *decresidual,       /* (i) decoded residual */
956                    int16_t *lpc,               /* (i) decoded LPC (only used for no PL) */
957                    int16_t inlag,              /* (i) pitch lag */
958                    ILBCContext *s)             /* (i/o) decoder instance */
959 {
960     int16_t i, pick;
961     int32_t cross, ener, cross_comp, ener_comp = 0;
962     int32_t measure, max_measure, energy;
963     int16_t max, cross_square_max, cross_square;
964     int16_t j, lag, tmp1, tmp2, randlag;
965     int16_t shift1, shift2, shift3, shift_max;
966     int16_t scale3;
967     int16_t corrLen;
968     int32_t tmpW32, tmp2W32;
969     int16_t use_gain;
970     int16_t tot_gain;
971     int16_t max_perSquare;
972     int16_t scale1, scale2;
973     int16_t totscale;
974     int32_t nom;
975     int16_t denom;
976     int16_t pitchfact;
977     int16_t use_lag;
978     int ind;
979     int16_t randvec[BLOCKL_MAX];
980 
981     /* Packet Loss */
982     if (PLI == 1) {
983 
984         s->consPLICount += 1;
985 
986         /* if previous frame not lost,
987            determine pitch pred. gain */
988 
989         if (s->prevPLI != 1) {
990 
991             /* Maximum 60 samples are correlated, preserve as high accuracy
992                as possible without getting overflow */
993             max = max_abs_value_w16(s->prevResidual, s->block_samples);
994             scale3 = (get_size_in_bits(max) << 1) - 25;
995             if (scale3 < 0) {
996                 scale3 = 0;
997             }
998 
999             /* Store scale for use when interpolating between the
1000              * concealment and the received packet */
1001             s->prevScale = scale3;
1002 
1003             /* Search around the previous lag +/-3 to find the
1004                best pitch period */
1005             lag = inlag - 3;
1006 
1007             /* Guard against getting outside the frame */
1008             corrLen = FFMIN(60, s->block_samples - (inlag + 3));
1009 
1010             correlation(&cross, &ener, s->prevResidual, lag, s->block_samples, corrLen, scale3);
1011 
1012             /* Normalize and store cross^2 and the number of shifts */
1013             shift_max = get_size_in_bits(FFABS(cross)) - 15;
1014             cross_square_max = (int16_t) SPL_MUL_16_16_RSFT(SPL_SHIFT_W32(cross, -shift_max), SPL_SHIFT_W32(cross, -shift_max), 15);
1015 
1016             for (j = inlag - 2; j <= inlag + 3; j++) {
1017                 correlation(&cross_comp, &ener_comp, s->prevResidual, j, s->block_samples, corrLen, scale3);
1018 
1019                 /* Use the criteria (corr*corr)/energy to compare if
1020                    this lag is better or not. To avoid the division,
1021                    do a cross multiplication */
1022                 shift1 = get_size_in_bits(FFABS(cross_comp)) - 15;
1023                 cross_square = (int16_t) SPL_MUL_16_16_RSFT(SPL_SHIFT_W32(cross_comp, -shift1), SPL_SHIFT_W32(cross_comp, -shift1), 15);
1024 
1025                 shift2 = get_size_in_bits(ener) - 15;
1026                 measure = SPL_MUL_16_16(SPL_SHIFT_W32(ener, -shift2), cross_square);
1027 
1028                 shift3 = get_size_in_bits(ener_comp) - 15;
1029                 max_measure = SPL_MUL_16_16(SPL_SHIFT_W32(ener_comp, -shift3), cross_square_max);
1030 
1031                 /* Calculate shift value, so that the two measures can
1032                    be put in the same Q domain */
1033                 if (((shift_max << 1) + shift3) > ((shift1 << 1) + shift2)) {
1034                     tmp1 = FFMIN(31, (shift_max << 1) + shift3 - (shift1 << 1) - shift2);
1035                     tmp2 = 0;
1036                 } else {
1037                     tmp1 = 0;
1038                     tmp2 = FFMIN(31, (shift1 << 1) + shift2 - (shift_max << 1) - shift3);
1039                 }
1040 
1041                 if ((measure >> tmp1) > (max_measure >> tmp2)) {
1042                     /* New lag is better => record lag, measure and domain */
1043                     lag = j;
1044                     cross_square_max = cross_square;
1045                     cross = cross_comp;
1046                     shift_max = shift1;
1047                     ener = ener_comp;
1048                 }
1049             }
1050 
1051             /* Calculate the periodicity for the lag with the maximum correlation.
1052 
1053                Definition of the periodicity:
1054                abs(corr(vec1, vec2))/(sqrt(energy(vec1))*sqrt(energy(vec2)))
1055 
1056                Work in the Square domain to simplify the calculations
1057                max_perSquare is less than 1 (in Q15)
1058              */
1059             tmp2W32 = scale_dot_product(&s->prevResidual[s->block_samples - corrLen], &s->prevResidual[s->block_samples - corrLen], corrLen, scale3);
1060 
1061             if ((tmp2W32 > 0) && (ener_comp > 0)) {
1062                 /* norm energies to int16_t, compute the product of the energies and
1063                    use the upper int16_t as the denominator */
1064 
1065                 scale1 = norm_w32(tmp2W32) - 16;
1066                 tmp1 = SPL_SHIFT_W32(tmp2W32, scale1);
1067 
1068                 scale2 = norm_w32(ener) - 16;
1069                 tmp2 =  SPL_SHIFT_W32(ener, scale2);
1070                 denom = SPL_MUL_16_16_RSFT(tmp1, tmp2, 16);    /* denom in Q(scale1+scale2-16) */
1071 
1072                 /* Square the cross correlation and norm it such that max_perSquare
1073                    will be in Q15 after the division */
1074 
1075                 totscale = scale1 + scale2 - 1;
1076                 tmp1 = SPL_SHIFT_W32(cross, (totscale >> 1));
1077                 tmp2 = SPL_SHIFT_W32(cross, totscale - (totscale >> 1));
1078 
1079                 nom = SPL_MUL_16_16(tmp1, tmp2);
1080                 max_perSquare = div_w32_w16(nom, denom);
1081             } else {
1082                 max_perSquare = 0;
1083             }
1084         } else {
1085             /* previous frame lost, use recorded lag and gain */
1086             lag = s->prevLag;
1087             max_perSquare = s->per_square;
1088         }
1089 
1090         /* Attenuate signal and scale down pitch pred gain if
1091            several frames lost consecutively */
1092 
1093         use_gain = 32767;       /* 1.0 in Q15 */
1094 
1095         if (s->consPLICount * s->block_samples > 320) {
1096             use_gain = 29491;   /* 0.9 in Q15 */
1097         } else if (s->consPLICount * s->block_samples > 640) {
1098             use_gain = 22938;   /* 0.7 in Q15 */
1099         } else if (s->consPLICount * s->block_samples > 960) {
1100             use_gain = 16384;   /* 0.5 in Q15 */
1101         } else if (s->consPLICount * s->block_samples > 1280) {
1102             use_gain = 0;       /* 0.0 in Q15 */
1103         }
1104 
1105         /* Compute mixing factor of picth repeatition and noise:
1106            for max_per>0.7 set periodicity to 1.0
1107            0.4<max_per<0.7 set periodicity to (maxper-0.4)/0.7-0.4)
1108            max_per<0.4 set periodicity to 0.0
1109          */
1110 
1111         if (max_perSquare > 7868) {     /* periodicity > 0.7  (0.7^4=0.2401 in Q15) */
1112             pitchfact = 32767;
1113         } else if (max_perSquare > 839) {       /* 0.4 < periodicity < 0.7 (0.4^4=0.0256 in Q15) */
1114             /* find best index and interpolate from that */
1115             ind = 5;
1116             while ((max_perSquare < kPlcPerSqr[ind]) && (ind > 0)) {
1117                 ind--;
1118             }
1119             /* pitch fact is approximated by first order */
1120             tmpW32 = kPlcPitchFact[ind] + SPL_MUL_16_16_RSFT(kPlcPfSlope[ind], (max_perSquare - kPlcPerSqr[ind]), 11);
1121 
1122             pitchfact = FFMIN(tmpW32, 32767); /* guard against overflow */
1123 
1124         } else {                /* periodicity < 0.4 */
1125             pitchfact = 0;
1126         }
1127 
1128         /* avoid repetition of same pitch cycle (buzzyness) */
1129         use_lag = lag;
1130         if (lag < 80) {
1131             use_lag = 2 * lag;
1132         }
1133 
1134         /* compute concealed residual */
1135         energy = 0;
1136 
1137         for (i = 0; i < s->block_samples; i++) {
1138             /* noise component -  52 < randlagFIX < 117 */
1139             s->seed = SPL_MUL_16_16(s->seed, 31821) + 13849;
1140             randlag = 53 + (s->seed & 63);
1141 
1142             pick = i - randlag;
1143 
1144             if (pick < 0) {
1145                 randvec[i] = s->prevResidual[s->block_samples + pick];
1146             } else {
1147                 randvec[i] = s->prevResidual[pick];
1148             }
1149 
1150             /* pitch repeatition component */
1151             pick = i - use_lag;
1152 
1153             if (pick < 0) {
1154                 plc_residual[i] = s->prevResidual[s->block_samples + pick];
1155             } else {
1156                 plc_residual[i] = plc_residual[pick];
1157             }
1158 
1159             /* Attinuate total gain for each 10 ms */
1160             if (i < 80) {
1161                 tot_gain = use_gain;
1162             } else if (i < 160) {
1163                 tot_gain = SPL_MUL_16_16_RSFT(31130, use_gain, 15);    /* 0.95*use_gain */
1164             } else {
1165                 tot_gain = SPL_MUL_16_16_RSFT(29491, use_gain, 15);    /* 0.9*use_gain */
1166             }
1167 
1168             /* mix noise and pitch repeatition */
1169             plc_residual[i] = SPL_MUL_16_16_RSFT(tot_gain, (pitchfact * plc_residual[i] + (32767 - pitchfact) * randvec[i] + 16384) >> 15, 15);
1170 
1171             /* Shifting down the result one step extra to ensure that no overflow
1172                will occur */
1173             energy += SPL_MUL_16_16_RSFT(plc_residual[i], plc_residual[i], (s->prevScale + 1));
1174 
1175         }
1176 
1177         /* less than 30 dB, use only noise */
1178         if (energy < SPL_SHIFT_W32(s->block_samples * 900, -s->prevScale - 1)) {
1179             energy = 0;
1180             for (i = 0; i < s->block_samples; i++) {
1181                 plc_residual[i] = randvec[i];
1182             }
1183         }
1184 
1185         /* use the old LPC */
1186         memcpy(plc_lpc, (*s).prev_lpc, (LPC_FILTERORDER + 1) * 2);
1187 
1188         /* Update state in case there are multiple frame losses */
1189         s->prevLag = lag;
1190         s->per_square = max_perSquare;
1191     } else { /* no packet loss, copy input */
1192         memcpy(plc_residual, decresidual, s->block_samples * 2);
1193         memcpy(plc_lpc, lpc, (LPC_FILTERORDER + 1) * 2);
1194         s->consPLICount = 0;
1195     }
1196 
1197     /* update state */
1198     s->prevPLI = PLI;
1199     memcpy(s->prev_lpc, plc_lpc, (LPC_FILTERORDER + 1) * 2);
1200     memcpy(s->prevResidual, plc_residual, s->block_samples * 2);
1201 
1202     return;
1203 }
1204 
xcorr_coeff(int16_t *target, int16_t *regressor, int16_t subl, int16_t searchLen, int16_t offset, int16_t step)1205 static int xcorr_coeff(int16_t *target, int16_t *regressor,
1206                        int16_t subl, int16_t searchLen,
1207                        int16_t offset, int16_t step)
1208 {
1209     int16_t maxlag;
1210     int16_t pos;
1211     int16_t max;
1212     int16_t cross_corr_scale, energy_scale;
1213     int16_t cross_corr_sg_mod, cross_corr_sg_mod_max;
1214     int32_t cross_corr, energy;
1215     int16_t cross_corr_mod, energy_mod, enery_mod_max;
1216     int16_t *tp, *rp;
1217     int16_t *rp_beg, *rp_end;
1218     int16_t totscale, totscale_max;
1219     int16_t scalediff;
1220     int32_t new_crit, max_crit;
1221     int shifts;
1222     int k;
1223 
1224     /* Initializations, to make sure that the first one is selected */
1225     cross_corr_sg_mod_max = 0;
1226     enery_mod_max = INT16_MAX;
1227     totscale_max = -500;
1228     maxlag = 0;
1229     pos = 0;
1230 
1231     /* Find scale value and start position */
1232     if (step == 1) {
1233         max = max_abs_value_w16(regressor, (int16_t) (subl + searchLen - 1));
1234         rp_beg = regressor;
1235         rp_end = &regressor[subl];
1236     } else {                    /* step== -1 */
1237         max = max_abs_value_w16(&regressor[-searchLen], (int16_t) (subl + searchLen - 1));
1238         rp_beg = &regressor[-1];
1239         rp_end = &regressor[subl - 1];
1240     }
1241 
1242     /* Introduce a scale factor on the energy in int32_t in
1243        order to make sure that the calculation does not
1244        overflow */
1245 
1246     if (max > 5000) {
1247         shifts = 2;
1248     } else {
1249         shifts = 0;
1250     }
1251 
1252     /* Calculate the first energy, then do a +/- to get the other energies */
1253     energy = scale_dot_product(regressor, regressor, subl, shifts);
1254 
1255     for (k = 0; k < searchLen; k++) {
1256         tp = target;
1257         rp = &regressor[pos];
1258 
1259         cross_corr = scale_dot_product(tp, rp, subl, shifts);
1260 
1261         if ((energy > 0) && (cross_corr > 0)) {
1262             /* Put cross correlation and energy on 16 bit word */
1263             cross_corr_scale = norm_w32(cross_corr) - 16;
1264             cross_corr_mod = (int16_t) SPL_SHIFT_W32(cross_corr, cross_corr_scale);
1265             energy_scale = norm_w32(energy) - 16;
1266             energy_mod = (int16_t) SPL_SHIFT_W32(energy, energy_scale);
1267 
1268             /* Square cross correlation and store upper int16_t */
1269             cross_corr_sg_mod = (int16_t) SPL_MUL_16_16_RSFT(cross_corr_mod, cross_corr_mod, 16);
1270 
1271             /* Calculate the total number of (dynamic) right shifts that have
1272                been performed on (cross_corr*cross_corr)/energy
1273              */
1274             totscale = energy_scale - (cross_corr_scale * 2);
1275 
1276             /* Calculate the shift difference in order to be able to compare the two
1277                (cross_corr*cross_corr)/energy in the same domain
1278              */
1279             scalediff = totscale - totscale_max;
1280             scalediff = FFMIN(scalediff, 31);
1281             scalediff = FFMAX(scalediff, -31);
1282 
1283             /* Compute the cross multiplication between the old best criteria
1284                and the new one to be able to compare them without using a
1285                division */
1286 
1287             if (scalediff < 0) {
1288                 new_crit = ((int32_t) cross_corr_sg_mod * enery_mod_max) >> (-scalediff);
1289                 max_crit = ((int32_t) cross_corr_sg_mod_max * energy_mod);
1290             } else {
1291                 new_crit = ((int32_t) cross_corr_sg_mod * enery_mod_max);
1292                 max_crit = ((int32_t) cross_corr_sg_mod_max * energy_mod) >> scalediff;
1293             }
1294 
1295             /* Store the new lag value if the new criteria is larger
1296                than previous largest criteria */
1297 
1298             if (new_crit > max_crit) {
1299                 cross_corr_sg_mod_max = cross_corr_sg_mod;
1300                 enery_mod_max = energy_mod;
1301                 totscale_max = totscale;
1302                 maxlag = k;
1303             }
1304         }
1305         pos += step;
1306 
1307         /* Do a +/- to get the next energy */
1308         energy += (unsigned)step * ((*rp_end * *rp_end - *rp_beg * *rp_beg) >> shifts);
1309 
1310         rp_beg += step;
1311         rp_end += step;
1312     }
1313 
1314     return maxlag + offset;
1315 }
1316 
hp_output(int16_t *signal, const int16_t *ba, int16_t *y, int16_t *x, int16_t len)1317 static void hp_output(int16_t *signal, const int16_t *ba, int16_t *y,
1318                       int16_t *x, int16_t len)
1319 {
1320     int32_t tmp;
1321 
1322     for (int i = 0; i < len; i++) {
1323         tmp = SPL_MUL_16_16(y[1], ba[3]);     /* (-a[1])*y[i-1] (low part) */
1324         tmp += SPL_MUL_16_16(y[3], ba[4]);    /* (-a[2])*y[i-2] (low part) */
1325         tmp = (tmp >> 15);
1326         tmp += SPL_MUL_16_16(y[0], ba[3]);    /* (-a[1])*y[i-1] (high part) */
1327         tmp += SPL_MUL_16_16(y[2], ba[4]);    /* (-a[2])*y[i-2] (high part) */
1328         tmp = (tmp * 2);
1329 
1330         tmp += SPL_MUL_16_16(signal[i], ba[0]);       /* b[0]*x[0] */
1331         tmp += SPL_MUL_16_16(x[0], ba[1]);    /* b[1]*x[i-1] */
1332         tmp += SPL_MUL_16_16(x[1], ba[2]);    /* b[2]*x[i-2] */
1333 
1334         /* Update state (input part) */
1335         x[1] = x[0];
1336         x[0] = signal[i];
1337 
1338         /* Convert back to Q0 and multiply with 2 */
1339         signal[i] = av_clip_intp2(tmp + 1024, 26) >> 11;
1340 
1341         /* Update state (filtered part) */
1342         y[2] = y[0];
1343         y[3] = y[1];
1344 
1345         /* upshift tmp by 3 with saturation */
1346         if (tmp > 268435455) {
1347             tmp = INT32_MAX;
1348         } else if (tmp < -268435456) {
1349             tmp = INT32_MIN;
1350         } else {
1351             tmp = tmp * 8;
1352         }
1353 
1354         y[0] = tmp >> 16;
1355         y[1] = (tmp - (y[0] * (1 << 16))) >> 1;
1356     }
1357 }
1358 
ilbc_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt)1359 static int ilbc_decode_frame(AVCodecContext *avctx, AVFrame *frame,
1360                              int *got_frame_ptr, AVPacket *avpkt)
1361 {
1362     const uint8_t *buf = avpkt->data;
1363     ILBCContext *s     = avctx->priv_data;
1364     int mode = s->mode, ret;
1365     int16_t *plc_data = &s->plc_residual[LPC_FILTERORDER];
1366 
1367     if ((ret = init_get_bits8(&s->gb, buf, avpkt->size)) < 0)
1368         return ret;
1369     memset(&s->frame, 0, sizeof(ILBCFrame));
1370 
1371     frame->nb_samples = s->block_samples;
1372     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1373         return ret;
1374 
1375     if (unpack_frame(s))
1376         mode = 0;
1377     if (s->frame.start < 1 || s->frame.start > 5)
1378         mode = 0;
1379 
1380     if (mode) {
1381         index_conv(s->frame.cb_index);
1382 
1383         lsf_dequantization(s->lsfdeq, s->frame.lsf, s->lpc_n);
1384         lsf_check_stability(s->lsfdeq, LPC_FILTERORDER, s->lpc_n);
1385         lsp_interpolate(s->syntdenum, s->weightdenum,
1386                         s->lsfdeq, LPC_FILTERORDER, s);
1387         decode_residual(s, &s->frame, s->decresidual, s->syntdenum);
1388 
1389         do_plc(s->plc_residual, s->plc_lpc, 0,
1390                                s->decresidual, s->syntdenum + (LPC_FILTERORDER + 1) * (s->nsub - 1),
1391                                s->last_lag, s);
1392 
1393         memcpy(s->decresidual, s->plc_residual, s->block_samples * 2);
1394     }
1395 
1396     if (s->enhancer) {
1397         /* TODO */
1398     } else {
1399         int16_t lag, i;
1400 
1401         /* Find last lag (since the enhancer is not called to give this info) */
1402         if (s->mode == 20) {
1403             lag = xcorr_coeff(&s->decresidual[s->block_samples-60], &s->decresidual[s->block_samples-80],
1404                               60, 80, 20, -1);
1405         } else {
1406             lag = xcorr_coeff(&s->decresidual[s->block_samples-ENH_BLOCKL],
1407                               &s->decresidual[s->block_samples-ENH_BLOCKL-20],
1408                               ENH_BLOCKL, 100, 20, -1);
1409         }
1410 
1411         /* Store lag (it is needed if next packet is lost) */
1412         s->last_lag = lag;
1413 
1414         /* copy data and run synthesis filter */
1415         memcpy(plc_data, s->decresidual, s->block_samples * 2);
1416 
1417         /* Set up the filter state */
1418         memcpy(&plc_data[-LPC_FILTERORDER], s->syntMem, LPC_FILTERORDER * 2);
1419 
1420         for (i = 0; i < s->nsub; i++) {
1421             filter_arfq12(plc_data+i*SUBL, plc_data+i*SUBL,
1422                                       s->syntdenum + i*(LPC_FILTERORDER + 1),
1423                                       LPC_FILTERORDER + 1, SUBL);
1424         }
1425 
1426         /* Save the filter state */
1427         memcpy(s->syntMem, &plc_data[s->block_samples-LPC_FILTERORDER], LPC_FILTERORDER * 2);
1428     }
1429 
1430     memcpy(frame->data[0], plc_data, s->block_samples * 2);
1431 
1432     hp_output((int16_t *)frame->data[0], hp_out_coeffs,
1433               s->hpimemy, s->hpimemx, s->block_samples);
1434 
1435     memcpy(s->old_syntdenum, s->syntdenum, s->nsub*(LPC_FILTERORDER + 1) * 2);
1436 
1437     s->prev_enh_pl = 0;
1438     if (mode == 0)
1439         s->prev_enh_pl = 1;
1440 
1441     *got_frame_ptr = 1;
1442 
1443     return avpkt->size;
1444 }
1445 
ilbc_decode_init(AVCodecContext *avctx)1446 static av_cold int ilbc_decode_init(AVCodecContext *avctx)
1447 {
1448     ILBCContext *s  = avctx->priv_data;
1449 
1450     if (avctx->block_align == 38)
1451         s->mode = 20;
1452     else if (avctx->block_align == 50)
1453         s->mode = 30;
1454     else if (avctx->bit_rate > 0)
1455         s->mode = avctx->bit_rate <= 14000 ? 30 : 20;
1456     else
1457         return AVERROR_INVALIDDATA;
1458 
1459     av_channel_layout_uninit(&avctx->ch_layout);
1460     avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
1461     avctx->sample_rate    = 8000;
1462     avctx->sample_fmt     = AV_SAMPLE_FMT_S16;
1463 
1464     if (s->mode == 30) {
1465         s->block_samples = 240;
1466         s->nsub = NSUB_30MS;
1467         s->nasub = NASUB_30MS;
1468         s->lpc_n = LPC_N_30MS;
1469         s->state_short_len = STATE_SHORT_LEN_30MS;
1470     } else {
1471         s->block_samples = 160;
1472         s->nsub = NSUB_20MS;
1473         s->nasub = NASUB_20MS;
1474         s->lpc_n = LPC_N_20MS;
1475         s->state_short_len = STATE_SHORT_LEN_20MS;
1476     }
1477 
1478     return 0;
1479 }
1480 
1481 const FFCodec ff_ilbc_decoder = {
1482     .p.name         = "ilbc",
1483     .p.long_name    = NULL_IF_CONFIG_SMALL("iLBC (Internet Low Bitrate Codec)"),
1484     .p.type         = AVMEDIA_TYPE_AUDIO,
1485     .p.id           = AV_CODEC_ID_ILBC,
1486     .init           = ilbc_decode_init,
1487     FF_CODEC_DECODE_CB(ilbc_decode_frame),
1488     .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
1489     .priv_data_size = sizeof(ILBCContext),
1490     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
1491 };
1492