1 /*
2  * G.723.1 compatible encoder
3  * Copyright (c) Mohamed Naufal <naufal22@gmail.com>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * G.723.1 compatible encoder
25  */
26 
27 #include <stdint.h>
28 #include <string.h>
29 
30 #include "libavutil/channel_layout.h"
31 #include "libavutil/common.h"
32 #include "libavutil/mem.h"
33 #include "libavutil/opt.h"
34 
35 #include "avcodec.h"
36 #include "celp_math.h"
37 #include "codec_internal.h"
38 #include "encode.h"
39 #include "g723_1.h"
40 
41 #define BITSTREAM_WRITER_LE
42 #include "put_bits.h"
43 
44 /**
45  * Hamming window coefficients scaled by 2^15
46  */
47 static const int16_t hamming_window[LPC_FRAME] = {
48      2621,  2631,  2659,  2705,  2770,  2853,  2955,  3074,  3212,  3367,
49      3541,  3731,  3939,  4164,  4405,  4663,  4937,  5226,  5531,  5851,
50      6186,  6534,  6897,  7273,  7661,  8062,  8475,  8899,  9334,  9780,
51     10235, 10699, 11172, 11653, 12141, 12636, 13138, 13645, 14157, 14673,
52     15193, 15716, 16242, 16769, 17298, 17827, 18356, 18884, 19411, 19935,
53     20457, 20975, 21489, 21999, 22503, 23002, 23494, 23978, 24455, 24924,
54     25384, 25834, 26274, 26704, 27122, 27529, 27924, 28306, 28675, 29031,
55     29373, 29700, 30012, 30310, 30592, 30857, 31107, 31340, 31557, 31756,
56     31938, 32102, 32249, 32377, 32488, 32580, 32654, 32710, 32747, 32766,
57     32766, 32747, 32710, 32654, 32580, 32488, 32377, 32249, 32102, 31938,
58     31756, 31557, 31340, 31107, 30857, 30592, 30310, 30012, 29700, 29373,
59     29031, 28675, 28306, 27924, 27529, 27122, 26704, 26274, 25834, 25384,
60     24924, 24455, 23978, 23494, 23002, 22503, 21999, 21489, 20975, 20457,
61     19935, 19411, 18884, 18356, 17827, 17298, 16769, 16242, 15716, 15193,
62     14673, 14157, 13645, 13138, 12636, 12141, 11653, 11172, 10699, 10235,
63      9780, 9334,   8899,  8475,  8062,  7661,  7273,  6897,  6534,  6186,
64      5851, 5531,   5226,  4937,  4663,  4405,  4164,  3939,  3731,  3541,
65      3367, 3212,   3074,  2955,  2853,  2770,  2705,  2659,  2631,  2621
66 };
67 
68 /**
69  * Binomial window coefficients scaled by 2^15
70  */
71 static const int16_t binomial_window[LPC_ORDER] = {
72     32749, 32695, 32604, 32477, 32315, 32118, 31887, 31622, 31324, 30995
73 };
74 
75 /**
76  * 0.994^i scaled by 2^15
77  */
78 static const int16_t bandwidth_expand[LPC_ORDER] = {
79     32571, 32376, 32182, 31989, 31797, 31606, 31416, 31228, 31040, 30854
80 };
81 
82 /**
83  * 0.5^i scaled by 2^15
84  */
85 static const int16_t percept_flt_tbl[2][LPC_ORDER] = {
86     /* Zero part */
87     {29491, 26542, 23888, 21499, 19349, 17414, 15673, 14106, 12695, 11425},
88     /* Pole part */
89     {16384,  8192,  4096,  2048,  1024,   512,   256,   128,    64,    32}
90 };
91 
g723_1_encode_init(AVCodecContext *avctx)92 static av_cold int g723_1_encode_init(AVCodecContext *avctx)
93 {
94     G723_1_Context *s = avctx->priv_data;
95     G723_1_ChannelContext *p = &s->ch[0];
96 
97     if (avctx->sample_rate != 8000) {
98         av_log(avctx, AV_LOG_ERROR, "Only 8000Hz sample rate supported\n");
99         return AVERROR(EINVAL);
100     }
101 
102     if (avctx->bit_rate == 6300) {
103         p->cur_rate = RATE_6300;
104     } else if (avctx->bit_rate == 5300) {
105         av_log(avctx, AV_LOG_ERROR, "Use bitrate 6300 instead of 5300.\n");
106         avpriv_report_missing_feature(avctx, "Bitrate 5300");
107         return AVERROR_PATCHWELCOME;
108     } else {
109         av_log(avctx, AV_LOG_ERROR, "Bitrate not supported, use 6300\n");
110         return AVERROR(EINVAL);
111     }
112     avctx->frame_size = 240;
113     memcpy(p->prev_lsp, dc_lsp, LPC_ORDER * sizeof(int16_t));
114 
115     return 0;
116 }
117 
118 /**
119  * Remove DC component from the input signal.
120  *
121  * @param buf input signal
122  * @param fir zero memory
123  * @param iir pole memory
124  */
highpass_filter(int16_t *buf, int16_t *fir, int *iir)125 static void highpass_filter(int16_t *buf, int16_t *fir, int *iir)
126 {
127     int i;
128     for (i = 0; i < FRAME_LEN; i++) {
129         *iir   = (buf[i] << 15) + ((-*fir) << 15) + MULL2(*iir, 0x7f00);
130         *fir   = buf[i];
131         buf[i] = av_clipl_int32((int64_t)*iir + (1 << 15)) >> 16;
132     }
133 }
134 
135 /**
136  * Estimate autocorrelation of the input vector.
137  *
138  * @param buf      input buffer
139  * @param autocorr autocorrelation coefficients vector
140  */
comp_autocorr(int16_t *buf, int16_t *autocorr)141 static void comp_autocorr(int16_t *buf, int16_t *autocorr)
142 {
143     int i, scale, temp;
144     int16_t vector[LPC_FRAME];
145 
146     ff_g723_1_scale_vector(vector, buf, LPC_FRAME);
147 
148     /* Apply the Hamming window */
149     for (i = 0; i < LPC_FRAME; i++)
150         vector[i] = (vector[i] * hamming_window[i] + (1 << 14)) >> 15;
151 
152     /* Compute the first autocorrelation coefficient */
153     temp = ff_dot_product(vector, vector, LPC_FRAME);
154 
155     /* Apply a white noise correlation factor of (1025/1024) */
156     temp += temp >> 10;
157 
158     /* Normalize */
159     scale       = ff_g723_1_normalize_bits(temp, 31);
160     autocorr[0] = av_clipl_int32((int64_t) (temp << scale) +
161                                  (1 << 15)) >> 16;
162 
163     /* Compute the remaining coefficients */
164     if (!autocorr[0]) {
165         memset(autocorr + 1, 0, LPC_ORDER * sizeof(int16_t));
166     } else {
167         for (i = 1; i <= LPC_ORDER; i++) {
168             temp        = ff_dot_product(vector, vector + i, LPC_FRAME - i);
169             temp        = MULL2((temp << scale), binomial_window[i - 1]);
170             autocorr[i] = av_clipl_int32((int64_t) temp + (1 << 15)) >> 16;
171         }
172     }
173 }
174 
175 /**
176  * Use Levinson-Durbin recursion to compute LPC coefficients from
177  * autocorrelation values.
178  *
179  * @param lpc      LPC coefficients vector
180  * @param autocorr autocorrelation coefficients vector
181  * @param error    prediction error
182  */
levinson_durbin(int16_t *lpc, int16_t *autocorr, int16_t error)183 static void levinson_durbin(int16_t *lpc, int16_t *autocorr, int16_t error)
184 {
185     int16_t vector[LPC_ORDER];
186     int16_t partial_corr;
187     int i, j, temp;
188 
189     memset(lpc, 0, LPC_ORDER * sizeof(int16_t));
190 
191     for (i = 0; i < LPC_ORDER; i++) {
192         /* Compute the partial correlation coefficient */
193         temp = 0;
194         for (j = 0; j < i; j++)
195             temp -= lpc[j] * autocorr[i - j - 1];
196         temp = ((autocorr[i] << 13) + temp) << 3;
197 
198         if (FFABS(temp) >= (error << 16))
199             break;
200 
201         partial_corr = temp / (error << 1);
202 
203         lpc[i] = av_clipl_int32((int64_t) (partial_corr << 14) +
204                                 (1 << 15)) >> 16;
205 
206         /* Update the prediction error */
207         temp  = MULL2(temp, partial_corr);
208         error = av_clipl_int32((int64_t) (error << 16) - temp +
209                                (1 << 15)) >> 16;
210 
211         memcpy(vector, lpc, i * sizeof(int16_t));
212         for (j = 0; j < i; j++) {
213             temp   = partial_corr * vector[i - j - 1] << 1;
214             lpc[j] = av_clipl_int32((int64_t) (lpc[j] << 16) - temp +
215                                     (1 << 15)) >> 16;
216         }
217     }
218 }
219 
220 /**
221  * Calculate LPC coefficients for the current frame.
222  *
223  * @param buf       current frame
224  * @param prev_data 2 trailing subframes of the previous frame
225  * @param lpc       LPC coefficients vector
226  */
comp_lpc_coeff(int16_t *buf, int16_t *lpc)227 static void comp_lpc_coeff(int16_t *buf, int16_t *lpc)
228 {
229     int16_t autocorr[(LPC_ORDER + 1) * SUBFRAMES];
230     int16_t *autocorr_ptr = autocorr;
231     int16_t *lpc_ptr      = lpc;
232     int i, j;
233 
234     for (i = 0, j = 0; j < SUBFRAMES; i += SUBFRAME_LEN, j++) {
235         comp_autocorr(buf + i, autocorr_ptr);
236         levinson_durbin(lpc_ptr, autocorr_ptr + 1, autocorr_ptr[0]);
237 
238         lpc_ptr      += LPC_ORDER;
239         autocorr_ptr += LPC_ORDER + 1;
240     }
241 }
242 
lpc2lsp(int16_t *lpc, int16_t *prev_lsp, int16_t *lsp)243 static void lpc2lsp(int16_t *lpc, int16_t *prev_lsp, int16_t *lsp)
244 {
245     int f[LPC_ORDER + 2]; ///< coefficients of the sum and difference
246                           ///< polynomials (F1, F2) ordered as
247                           ///< f1[0], f2[0], ...., f1[5], f2[5]
248 
249     int max, shift, cur_val, prev_val, count, p;
250     int i, j;
251     int64_t temp;
252 
253     /* Initialize f1[0] and f2[0] to 1 in Q25 */
254     for (i = 0; i < LPC_ORDER; i++)
255         lsp[i] = (lpc[i] * bandwidth_expand[i] + (1 << 14)) >> 15;
256 
257     /* Apply bandwidth expansion on the LPC coefficients */
258     f[0] = f[1] = 1 << 25;
259 
260     /* Compute the remaining coefficients */
261     for (i = 0; i < LPC_ORDER / 2; i++) {
262         /* f1 */
263         f[2 * i + 2] = -f[2 * i] - ((lsp[i] + lsp[LPC_ORDER - 1 - i]) << 12);
264         /* f2 */
265         f[2 * i + 3] = f[2 * i + 1] - ((lsp[i] - lsp[LPC_ORDER - 1 - i]) << 12);
266     }
267 
268     /* Divide f1[5] and f2[5] by 2 for use in polynomial evaluation */
269     f[LPC_ORDER]     >>= 1;
270     f[LPC_ORDER + 1] >>= 1;
271 
272     /* Normalize and shorten */
273     max = FFABS(f[0]);
274     for (i = 1; i < LPC_ORDER + 2; i++)
275         max = FFMAX(max, FFABS(f[i]));
276 
277     shift = ff_g723_1_normalize_bits(max, 31);
278 
279     for (i = 0; i < LPC_ORDER + 2; i++)
280         f[i] = av_clipl_int32((int64_t) (f[i] << shift) + (1 << 15)) >> 16;
281 
282     /**
283      * Evaluate F1 and F2 at uniform intervals of pi/256 along the
284      * unit circle and check for zero crossings.
285      */
286     p    = 0;
287     temp = 0;
288     for (i = 0; i <= LPC_ORDER / 2; i++)
289         temp += f[2 * i] * G723_1_COS_TAB_FIRST_ELEMENT;
290     prev_val = av_clipl_int32(temp << 1);
291     count    = 0;
292     for (i = 1; i < COS_TBL_SIZE / 2; i++) {
293         /* Evaluate */
294         temp = 0;
295         for (j = 0; j <= LPC_ORDER / 2; j++)
296             temp += f[LPC_ORDER - 2 * j + p] * ff_g723_1_cos_tab[i * j % COS_TBL_SIZE];
297         cur_val = av_clipl_int32(temp << 1);
298 
299         /* Check for sign change, indicating a zero crossing */
300         if ((cur_val ^ prev_val) < 0) {
301             int abs_cur  = FFABS(cur_val);
302             int abs_prev = FFABS(prev_val);
303             int sum      = abs_cur + abs_prev;
304 
305             shift        = ff_g723_1_normalize_bits(sum, 31);
306             sum        <<= shift;
307             abs_prev     = abs_prev << shift >> 8;
308             lsp[count++] = ((i - 1) << 7) + (abs_prev >> 1) / (sum >> 16);
309 
310             if (count == LPC_ORDER)
311                 break;
312 
313             /* Switch between sum and difference polynomials */
314             p ^= 1;
315 
316             /* Evaluate */
317             temp = 0;
318             for (j = 0; j <= LPC_ORDER / 2; j++)
319                 temp += f[LPC_ORDER - 2 * j + p] *
320                         ff_g723_1_cos_tab[i * j % COS_TBL_SIZE];
321             cur_val = av_clipl_int32(temp << 1);
322         }
323         prev_val = cur_val;
324     }
325 
326     if (count != LPC_ORDER)
327         memcpy(lsp, prev_lsp, LPC_ORDER * sizeof(int16_t));
328 }
329 
330 /**
331  * Quantize the current LSP subvector.
332  *
333  * @param num    band number
334  * @param offset offset of the current subvector in an LPC_ORDER vector
335  * @param size   size of the current subvector
336  */
337 #define get_index(num, offset, size)                                          \
338 {                                                                             \
339     int error, max = -1;                                                      \
340     int16_t temp[4];                                                          \
341     int i, j;                                                                 \
342                                                                               \
343     for (i = 0; i < LSP_CB_SIZE; i++) {                                       \
344         for (j = 0; j < size; j++){                                           \
345             temp[j] = (weight[j + (offset)] * ff_g723_1_lsp_band##num[i][j] + \
346                       (1 << 14)) >> 15;                                       \
347         }                                                                     \
348         error  = ff_g723_1_dot_product(lsp + (offset), temp, size) << 1;      \
349         error -= ff_g723_1_dot_product(ff_g723_1_lsp_band##num[i], temp, size); \
350         if (error > max) {                                                    \
351             max = error;                                                      \
352             lsp_index[num] = i;                                               \
353         }                                                                     \
354     }                                                                         \
355 }
356 
357 /**
358  * Vector quantize the LSP frequencies.
359  *
360  * @param lsp      the current lsp vector
361  * @param prev_lsp the previous lsp vector
362  */
lsp_quantize(uint8_t *lsp_index, int16_t *lsp, int16_t *prev_lsp)363 static void lsp_quantize(uint8_t *lsp_index, int16_t *lsp, int16_t *prev_lsp)
364 {
365     int16_t weight[LPC_ORDER];
366     int16_t min, max;
367     int shift, i;
368 
369     /* Calculate the VQ weighting vector */
370     weight[0]             = (1 << 20) / (lsp[1] - lsp[0]);
371     weight[LPC_ORDER - 1] = (1 << 20) /
372                             (lsp[LPC_ORDER - 1] - lsp[LPC_ORDER - 2]);
373 
374     for (i = 1; i < LPC_ORDER - 1; i++) {
375         min = FFMIN(lsp[i] - lsp[i - 1], lsp[i + 1] - lsp[i]);
376         if (min > 0x20)
377             weight[i] = (1 << 20) / min;
378         else
379             weight[i] = INT16_MAX;
380     }
381 
382     /* Normalize */
383     max = 0;
384     for (i = 0; i < LPC_ORDER; i++)
385         max = FFMAX(weight[i], max);
386 
387     shift = ff_g723_1_normalize_bits(max, 15);
388     for (i = 0; i < LPC_ORDER; i++) {
389         weight[i] <<= shift;
390     }
391 
392     /* Compute the VQ target vector */
393     for (i = 0; i < LPC_ORDER; i++) {
394         lsp[i] -= dc_lsp[i] +
395                   (((prev_lsp[i] - dc_lsp[i]) * 12288 + (1 << 14)) >> 15);
396     }
397 
398     get_index(0, 0, 3);
399     get_index(1, 3, 3);
400     get_index(2, 6, 4);
401 }
402 
403 /**
404  * Perform IIR filtering.
405  *
406  * @param fir_coef FIR coefficients
407  * @param iir_coef IIR coefficients
408  * @param src      source vector
409  * @param dest     destination vector
410  */
iir_filter(int16_t *fir_coef, int16_t *iir_coef, int16_t *src, int16_t *dest)411 static void iir_filter(int16_t *fir_coef, int16_t *iir_coef,
412                        int16_t *src, int16_t *dest)
413 {
414     int m, n;
415 
416     for (m = 0; m < SUBFRAME_LEN; m++) {
417         int64_t filter = 0;
418         for (n = 1; n <= LPC_ORDER; n++) {
419             filter -= fir_coef[n - 1] * src[m - n] -
420                       iir_coef[n - 1] * dest[m - n];
421         }
422 
423         dest[m] = av_clipl_int32((src[m] << 16) + (filter << 3) +
424                                  (1 << 15)) >> 16;
425     }
426 }
427 
428 /**
429  * Apply the formant perceptual weighting filter.
430  *
431  * @param flt_coef filter coefficients
432  * @param unq_lpc  unquantized lpc vector
433  */
perceptual_filter(G723_1_ChannelContext *p, int16_t *flt_coef, int16_t *unq_lpc, int16_t *buf)434 static void perceptual_filter(G723_1_ChannelContext *p, int16_t *flt_coef,
435                               int16_t *unq_lpc, int16_t *buf)
436 {
437     int16_t vector[FRAME_LEN + LPC_ORDER];
438     int i, j, k, l = 0;
439 
440     memcpy(buf, p->iir_mem, sizeof(int16_t) * LPC_ORDER);
441     memcpy(vector, p->fir_mem, sizeof(int16_t) * LPC_ORDER);
442     memcpy(vector + LPC_ORDER, buf + LPC_ORDER, sizeof(int16_t) * FRAME_LEN);
443 
444     for (i = LPC_ORDER, j = 0; j < SUBFRAMES; i += SUBFRAME_LEN, j++) {
445         for (k = 0; k < LPC_ORDER; k++) {
446             flt_coef[k + 2 * l] = (unq_lpc[k + l] * percept_flt_tbl[0][k] +
447                                    (1 << 14)) >> 15;
448             flt_coef[k + 2 * l + LPC_ORDER] = (unq_lpc[k + l] *
449                                                percept_flt_tbl[1][k] +
450                                                (1 << 14)) >> 15;
451         }
452         iir_filter(flt_coef + 2 * l, flt_coef + 2 * l + LPC_ORDER,
453                    vector + i, buf + i);
454         l += LPC_ORDER;
455     }
456     memcpy(p->iir_mem, buf + FRAME_LEN, sizeof(int16_t) * LPC_ORDER);
457     memcpy(p->fir_mem, vector + FRAME_LEN, sizeof(int16_t) * LPC_ORDER);
458 }
459 
460 /**
461  * Estimate the open loop pitch period.
462  *
463  * @param buf   perceptually weighted speech
464  * @param start estimation is carried out from this position
465  */
estimate_pitch(int16_t *buf, int start)466 static int estimate_pitch(int16_t *buf, int start)
467 {
468     int max_exp = 32;
469     int max_ccr = 0x4000;
470     int max_eng = 0x7fff;
471     int index   = PITCH_MIN;
472     int offset  = start - PITCH_MIN + 1;
473 
474     int ccr, eng, orig_eng, ccr_eng, exp;
475     int diff, temp;
476 
477     int i;
478 
479     orig_eng = ff_dot_product(buf + offset, buf + offset, HALF_FRAME_LEN);
480 
481     for (i = PITCH_MIN; i <= PITCH_MAX - 3; i++) {
482         offset--;
483 
484         /* Update energy and compute correlation */
485         orig_eng += buf[offset] * buf[offset] -
486                     buf[offset + HALF_FRAME_LEN] * buf[offset + HALF_FRAME_LEN];
487         ccr = ff_dot_product(buf + start, buf + offset, HALF_FRAME_LEN);
488         if (ccr <= 0)
489             continue;
490 
491         /* Split into mantissa and exponent to maintain precision */
492         exp   = ff_g723_1_normalize_bits(ccr, 31);
493         ccr   = av_clipl_int32((int64_t) (ccr << exp) + (1 << 15)) >> 16;
494         exp <<= 1;
495         ccr  *= ccr;
496         temp  = ff_g723_1_normalize_bits(ccr, 31);
497         ccr   = ccr << temp >> 16;
498         exp  += temp;
499 
500         temp = ff_g723_1_normalize_bits(orig_eng, 31);
501         eng  = av_clipl_int32((int64_t) (orig_eng << temp) + (1 << 15)) >> 16;
502         exp -= temp;
503 
504         if (ccr >= eng) {
505             exp--;
506             ccr >>= 1;
507         }
508         if (exp > max_exp)
509             continue;
510 
511         if (exp + 1 < max_exp)
512             goto update;
513 
514         /* Equalize exponents before comparison */
515         if (exp + 1 == max_exp)
516             temp = max_ccr >> 1;
517         else
518             temp = max_ccr;
519         ccr_eng = ccr * max_eng;
520         diff    = ccr_eng - eng * temp;
521         if (diff > 0 && (i - index < PITCH_MIN || diff > ccr_eng >> 2)) {
522 update:
523             index   = i;
524             max_exp = exp;
525             max_ccr = ccr;
526             max_eng = eng;
527         }
528     }
529     return index;
530 }
531 
532 /**
533  * Compute harmonic noise filter parameters.
534  *
535  * @param buf       perceptually weighted speech
536  * @param pitch_lag open loop pitch period
537  * @param hf        harmonic filter parameters
538  */
comp_harmonic_coeff(int16_t *buf, int16_t pitch_lag, HFParam *hf)539 static void comp_harmonic_coeff(int16_t *buf, int16_t pitch_lag, HFParam *hf)
540 {
541     int ccr, eng, max_ccr, max_eng;
542     int exp, max, diff;
543     int energy[15];
544     int i, j;
545 
546     for (i = 0, j = pitch_lag - 3; j <= pitch_lag + 3; i++, j++) {
547         /* Compute residual energy */
548         energy[i << 1] = ff_dot_product(buf - j, buf - j, SUBFRAME_LEN);
549         /* Compute correlation */
550         energy[(i << 1) + 1] = ff_dot_product(buf, buf - j, SUBFRAME_LEN);
551     }
552 
553     /* Compute target energy */
554     energy[14] = ff_dot_product(buf, buf, SUBFRAME_LEN);
555 
556     /* Normalize */
557     max = 0;
558     for (i = 0; i < 15; i++)
559         max = FFMAX(max, FFABS(energy[i]));
560 
561     exp = ff_g723_1_normalize_bits(max, 31);
562     for (i = 0; i < 15; i++) {
563         energy[i] = av_clipl_int32((int64_t)(energy[i] << exp) +
564                                    (1 << 15)) >> 16;
565     }
566 
567     hf->index = -1;
568     hf->gain  =  0;
569     max_ccr   =  1;
570     max_eng   =  0x7fff;
571 
572     for (i = 0; i <= 6; i++) {
573         eng = energy[i << 1];
574         ccr = energy[(i << 1) + 1];
575 
576         if (ccr <= 0)
577             continue;
578 
579         ccr  = (ccr * ccr + (1 << 14)) >> 15;
580         diff = ccr * max_eng - eng * max_ccr;
581         if (diff > 0) {
582             max_ccr   = ccr;
583             max_eng   = eng;
584             hf->index = i;
585         }
586     }
587 
588     if (hf->index == -1) {
589         hf->index = pitch_lag;
590         return;
591     }
592 
593     eng = energy[14] * max_eng;
594     eng = (eng >> 2) + (eng >> 3);
595     ccr = energy[(hf->index << 1) + 1] * energy[(hf->index << 1) + 1];
596     if (eng < ccr) {
597         eng = energy[(hf->index << 1) + 1];
598 
599         if (eng >= max_eng)
600             hf->gain = 0x2800;
601         else
602             hf->gain = ((eng << 15) / max_eng * 0x2800 + (1 << 14)) >> 15;
603     }
604     hf->index += pitch_lag - 3;
605 }
606 
607 /**
608  * Apply the harmonic noise shaping filter.
609  *
610  * @param hf filter parameters
611  */
harmonic_filter(HFParam *hf, const int16_t *src, int16_t *dest)612 static void harmonic_filter(HFParam *hf, const int16_t *src, int16_t *dest)
613 {
614     int i;
615 
616     for (i = 0; i < SUBFRAME_LEN; i++) {
617         int64_t temp = hf->gain * src[i - hf->index] << 1;
618         dest[i] = av_clipl_int32((src[i] << 16) - temp + (1 << 15)) >> 16;
619     }
620 }
621 
harmonic_noise_sub(HFParam *hf, const int16_t *src, int16_t *dest)622 static void harmonic_noise_sub(HFParam *hf, const int16_t *src, int16_t *dest)
623 {
624     int i;
625     for (i = 0; i < SUBFRAME_LEN; i++) {
626         int64_t temp = hf->gain * src[i - hf->index] << 1;
627         dest[i] = av_clipl_int32(((dest[i] - src[i]) << 16) + temp +
628                                  (1 << 15)) >> 16;
629     }
630 }
631 
632 /**
633  * Combined synthesis and formant perceptual weighting filer.
634  *
635  * @param qnt_lpc  quantized lpc coefficients
636  * @param perf_lpc perceptual filter coefficients
637  * @param perf_fir perceptual filter fir memory
638  * @param perf_iir perceptual filter iir memory
639  * @param scale    the filter output will be scaled by 2^scale
640  */
synth_percept_filter(int16_t *qnt_lpc, int16_t *perf_lpc, int16_t *perf_fir, int16_t *perf_iir, const int16_t *src, int16_t *dest, int scale)641 static void synth_percept_filter(int16_t *qnt_lpc, int16_t *perf_lpc,
642                                  int16_t *perf_fir, int16_t *perf_iir,
643                                  const int16_t *src, int16_t *dest, int scale)
644 {
645     int i, j;
646     int16_t buf_16[SUBFRAME_LEN + LPC_ORDER];
647     int64_t buf[SUBFRAME_LEN];
648 
649     int16_t *bptr_16 = buf_16 + LPC_ORDER;
650 
651     memcpy(buf_16, perf_fir, sizeof(int16_t) * LPC_ORDER);
652     memcpy(dest - LPC_ORDER, perf_iir, sizeof(int16_t) * LPC_ORDER);
653 
654     for (i = 0; i < SUBFRAME_LEN; i++) {
655         int64_t temp = 0;
656         for (j = 1; j <= LPC_ORDER; j++)
657             temp -= qnt_lpc[j - 1] * bptr_16[i - j];
658 
659         buf[i]     = (src[i] << 15) + (temp << 3);
660         bptr_16[i] = av_clipl_int32(buf[i] + (1 << 15)) >> 16;
661     }
662 
663     for (i = 0; i < SUBFRAME_LEN; i++) {
664         int64_t fir = 0, iir = 0;
665         for (j = 1; j <= LPC_ORDER; j++) {
666             fir -= perf_lpc[j - 1] * bptr_16[i - j];
667             iir += perf_lpc[j + LPC_ORDER - 1] * dest[i - j];
668         }
669         dest[i] = av_clipl_int32(((buf[i] + (fir << 3)) << scale) + (iir << 3) +
670                                  (1 << 15)) >> 16;
671     }
672     memcpy(perf_fir, buf_16 + SUBFRAME_LEN, sizeof(int16_t) * LPC_ORDER);
673     memcpy(perf_iir, dest + SUBFRAME_LEN - LPC_ORDER,
674            sizeof(int16_t) * LPC_ORDER);
675 }
676 
677 /**
678  * Compute the adaptive codebook contribution.
679  *
680  * @param buf   input signal
681  * @param index the current subframe index
682  */
acb_search(G723_1_ChannelContext *p, int16_t *residual, int16_t *impulse_resp, const int16_t *buf, int index)683 static void acb_search(G723_1_ChannelContext *p, int16_t *residual,
684                        int16_t *impulse_resp, const int16_t *buf,
685                        int index)
686 {
687     int16_t flt_buf[PITCH_ORDER][SUBFRAME_LEN];
688 
689     const int16_t *cb_tbl = ff_g723_1_adaptive_cb_gain85;
690 
691     int ccr_buf[PITCH_ORDER * SUBFRAMES << 2];
692 
693     int pitch_lag = p->pitch_lag[index >> 1];
694     int acb_lag   = 1;
695     int acb_gain  = 0;
696     int odd_frame = index & 1;
697     int iter      = 3 + odd_frame;
698     int count     = 0;
699     int tbl_size  = 85;
700 
701     int i, j, k, l, max;
702     int64_t temp;
703 
704     if (!odd_frame) {
705         if (pitch_lag == PITCH_MIN)
706             pitch_lag++;
707         else
708             pitch_lag = FFMIN(pitch_lag, PITCH_MAX - 5);
709     }
710 
711     for (i = 0; i < iter; i++) {
712         ff_g723_1_get_residual(residual, p->prev_excitation, pitch_lag + i - 1);
713 
714         for (j = 0; j < SUBFRAME_LEN; j++) {
715             temp = 0;
716             for (k = 0; k <= j; k++)
717                 temp += residual[PITCH_ORDER - 1 + k] * impulse_resp[j - k];
718             flt_buf[PITCH_ORDER - 1][j] = av_clipl_int32((temp << 1) +
719                                                          (1 << 15)) >> 16;
720         }
721 
722         for (j = PITCH_ORDER - 2; j >= 0; j--) {
723             flt_buf[j][0] = ((residual[j] << 13) + (1 << 14)) >> 15;
724             for (k = 1; k < SUBFRAME_LEN; k++) {
725                 temp = (flt_buf[j + 1][k - 1] << 15) +
726                        residual[j] * impulse_resp[k];
727                 flt_buf[j][k] = av_clipl_int32((temp << 1) + (1 << 15)) >> 16;
728             }
729         }
730 
731         /* Compute crosscorrelation with the signal */
732         for (j = 0; j < PITCH_ORDER; j++) {
733             temp             = ff_dot_product(buf, flt_buf[j], SUBFRAME_LEN);
734             ccr_buf[count++] = av_clipl_int32(temp << 1);
735         }
736 
737         /* Compute energies */
738         for (j = 0; j < PITCH_ORDER; j++) {
739             ccr_buf[count++] = ff_g723_1_dot_product(flt_buf[j], flt_buf[j],
740                                                      SUBFRAME_LEN);
741         }
742 
743         for (j = 1; j < PITCH_ORDER; j++) {
744             for (k = 0; k < j; k++) {
745                 temp             = ff_dot_product(flt_buf[j], flt_buf[k], SUBFRAME_LEN);
746                 ccr_buf[count++] = av_clipl_int32(temp << 2);
747             }
748         }
749     }
750 
751     /* Normalize and shorten */
752     max = 0;
753     for (i = 0; i < 20 * iter; i++)
754         max = FFMAX(max, FFABS(ccr_buf[i]));
755 
756     temp = ff_g723_1_normalize_bits(max, 31);
757 
758     for (i = 0; i < 20 * iter; i++)
759         ccr_buf[i] = av_clipl_int32((int64_t) (ccr_buf[i] << temp) +
760                                     (1 << 15)) >> 16;
761 
762     max = 0;
763     for (i = 0; i < iter; i++) {
764         /* Select quantization table */
765         if (!odd_frame && pitch_lag + i - 1 >= SUBFRAME_LEN - 2 ||
766             odd_frame && pitch_lag >= SUBFRAME_LEN - 2) {
767             cb_tbl   = ff_g723_1_adaptive_cb_gain170;
768             tbl_size = 170;
769         }
770 
771         for (j = 0, k = 0; j < tbl_size; j++, k += 20) {
772             temp = 0;
773             for (l = 0; l < 20; l++)
774                 temp += ccr_buf[20 * i + l] * cb_tbl[k + l];
775             temp = av_clipl_int32(temp);
776 
777             if (temp > max) {
778                 max      = temp;
779                 acb_gain = j;
780                 acb_lag  = i;
781             }
782         }
783     }
784 
785     if (!odd_frame) {
786         pitch_lag += acb_lag - 1;
787         acb_lag    = 1;
788     }
789 
790     p->pitch_lag[index >> 1]      = pitch_lag;
791     p->subframe[index].ad_cb_lag  = acb_lag;
792     p->subframe[index].ad_cb_gain = acb_gain;
793 }
794 
795 /**
796  * Subtract the adaptive codebook contribution from the input
797  * to obtain the residual.
798  *
799  * @param buf target vector
800  */
sub_acb_contrib(const int16_t *residual, const int16_t *impulse_resp, int16_t *buf)801 static void sub_acb_contrib(const int16_t *residual, const int16_t *impulse_resp,
802                             int16_t *buf)
803 {
804     int i, j;
805     /* Subtract adaptive CB contribution to obtain the residual */
806     for (i = 0; i < SUBFRAME_LEN; i++) {
807         int64_t temp = buf[i] << 14;
808         for (j = 0; j <= i; j++)
809             temp -= residual[j] * impulse_resp[i - j];
810 
811         buf[i] = av_clipl_int32((temp << 2) + (1 << 15)) >> 16;
812     }
813 }
814 
815 /**
816  * Quantize the residual signal using the fixed codebook (MP-MLQ).
817  *
818  * @param optim optimized fixed codebook parameters
819  * @param buf   excitation vector
820  */
get_fcb_param(FCBParam *optim, int16_t *impulse_resp, int16_t *buf, int pulse_cnt, int pitch_lag)821 static void get_fcb_param(FCBParam *optim, int16_t *impulse_resp,
822                           int16_t *buf, int pulse_cnt, int pitch_lag)
823 {
824     FCBParam param;
825     int16_t impulse_r[SUBFRAME_LEN];
826     int16_t temp_corr[SUBFRAME_LEN];
827     int16_t impulse_corr[SUBFRAME_LEN];
828 
829     int ccr1[SUBFRAME_LEN];
830     int ccr2[SUBFRAME_LEN];
831     int amp, err, max, max_amp_index, min, scale, i, j, k, l;
832 
833     int64_t temp;
834 
835     /* Update impulse response */
836     memcpy(impulse_r, impulse_resp, sizeof(int16_t) * SUBFRAME_LEN);
837     param.dirac_train = 0;
838     if (pitch_lag < SUBFRAME_LEN - 2) {
839         param.dirac_train = 1;
840         ff_g723_1_gen_dirac_train(impulse_r, pitch_lag);
841     }
842 
843     for (i = 0; i < SUBFRAME_LEN; i++)
844         temp_corr[i] = impulse_r[i] >> 1;
845 
846     /* Compute impulse response autocorrelation */
847     temp = ff_g723_1_dot_product(temp_corr, temp_corr, SUBFRAME_LEN);
848 
849     scale           = ff_g723_1_normalize_bits(temp, 31);
850     impulse_corr[0] = av_clipl_int32((temp << scale) + (1 << 15)) >> 16;
851 
852     for (i = 1; i < SUBFRAME_LEN; i++) {
853         temp = ff_g723_1_dot_product(temp_corr + i, temp_corr,
854                                      SUBFRAME_LEN - i);
855         impulse_corr[i] = av_clipl_int32((temp << scale) + (1 << 15)) >> 16;
856     }
857 
858     /* Compute crosscorrelation of impulse response with residual signal */
859     scale -= 4;
860     for (i = 0; i < SUBFRAME_LEN; i++) {
861         temp = ff_g723_1_dot_product(buf + i, impulse_r, SUBFRAME_LEN - i);
862         if (scale < 0)
863             ccr1[i] = temp >> -scale;
864         else
865             ccr1[i] = av_clipl_int32(temp << scale);
866     }
867 
868     /* Search loop */
869     for (i = 0; i < GRID_SIZE; i++) {
870         /* Maximize the crosscorrelation */
871         max = 0;
872         for (j = i; j < SUBFRAME_LEN; j += GRID_SIZE) {
873             temp = FFABS(ccr1[j]);
874             if (temp >= max) {
875                 max                = temp;
876                 param.pulse_pos[0] = j;
877             }
878         }
879 
880         /* Quantize the gain (max crosscorrelation/impulse_corr[0]) */
881         amp           = max;
882         min           = 1 << 30;
883         max_amp_index = GAIN_LEVELS - 2;
884         for (j = max_amp_index; j >= 2; j--) {
885             temp = av_clipl_int32((int64_t) ff_g723_1_fixed_cb_gain[j] *
886                                   impulse_corr[0] << 1);
887             temp = FFABS(temp - amp);
888             if (temp < min) {
889                 min           = temp;
890                 max_amp_index = j;
891             }
892         }
893 
894         max_amp_index--;
895         /* Select additional gain values */
896         for (j = 1; j < 5; j++) {
897             for (k = i; k < SUBFRAME_LEN; k += GRID_SIZE) {
898                 temp_corr[k] = 0;
899                 ccr2[k]      = ccr1[k];
900             }
901             param.amp_index = max_amp_index + j - 2;
902             amp             = ff_g723_1_fixed_cb_gain[param.amp_index];
903 
904             param.pulse_sign[0] = (ccr2[param.pulse_pos[0]] < 0) ? -amp : amp;
905             temp_corr[param.pulse_pos[0]] = 1;
906 
907             for (k = 1; k < pulse_cnt; k++) {
908                 max = INT_MIN;
909                 for (l = i; l < SUBFRAME_LEN; l += GRID_SIZE) {
910                     if (temp_corr[l])
911                         continue;
912                     temp = impulse_corr[FFABS(l - param.pulse_pos[k - 1])];
913                     temp = av_clipl_int32((int64_t) temp *
914                                           param.pulse_sign[k - 1] << 1);
915                     ccr2[l] -= temp;
916                     temp     = FFABS(ccr2[l]);
917                     if (temp > max) {
918                         max                = temp;
919                         param.pulse_pos[k] = l;
920                     }
921                 }
922 
923                 param.pulse_sign[k] = (ccr2[param.pulse_pos[k]] < 0) ?
924                                       -amp : amp;
925                 temp_corr[param.pulse_pos[k]] = 1;
926             }
927 
928             /* Create the error vector */
929             memset(temp_corr, 0, sizeof(int16_t) * SUBFRAME_LEN);
930 
931             for (k = 0; k < pulse_cnt; k++)
932                 temp_corr[param.pulse_pos[k]] = param.pulse_sign[k];
933 
934             for (k = SUBFRAME_LEN - 1; k >= 0; k--) {
935                 temp = 0;
936                 for (l = 0; l <= k; l++) {
937                     int prod = av_clipl_int32((int64_t) temp_corr[l] *
938                                               impulse_r[k - l] << 1);
939                     temp = av_clipl_int32(temp + prod);
940                 }
941                 temp_corr[k] = temp << 2 >> 16;
942             }
943 
944             /* Compute square of error */
945             err = 0;
946             for (k = 0; k < SUBFRAME_LEN; k++) {
947                 int64_t prod;
948                 prod = av_clipl_int32((int64_t) buf[k] * temp_corr[k] << 1);
949                 err  = av_clipl_int32(err - prod);
950                 prod = av_clipl_int32((int64_t) temp_corr[k] * temp_corr[k]);
951                 err  = av_clipl_int32(err + prod);
952             }
953 
954             /* Minimize */
955             if (err < optim->min_err) {
956                 optim->min_err     = err;
957                 optim->grid_index  = i;
958                 optim->amp_index   = param.amp_index;
959                 optim->dirac_train = param.dirac_train;
960 
961                 for (k = 0; k < pulse_cnt; k++) {
962                     optim->pulse_sign[k] = param.pulse_sign[k];
963                     optim->pulse_pos[k]  = param.pulse_pos[k];
964                 }
965             }
966         }
967     }
968 }
969 
970 /**
971  * Encode the pulse position and gain of the current subframe.
972  *
973  * @param optim optimized fixed CB parameters
974  * @param buf   excitation vector
975  */
pack_fcb_param(G723_1_Subframe *subfrm, FCBParam *optim, int16_t *buf, int pulse_cnt)976 static void pack_fcb_param(G723_1_Subframe *subfrm, FCBParam *optim,
977                            int16_t *buf, int pulse_cnt)
978 {
979     int i, j;
980 
981     j = PULSE_MAX - pulse_cnt;
982 
983     subfrm->pulse_sign = 0;
984     subfrm->pulse_pos  = 0;
985 
986     for (i = 0; i < SUBFRAME_LEN >> 1; i++) {
987         int val = buf[optim->grid_index + (i << 1)];
988         if (!val) {
989             subfrm->pulse_pos += ff_g723_1_combinatorial_table[j][i];
990         } else {
991             subfrm->pulse_sign <<= 1;
992             if (val < 0)
993                 subfrm->pulse_sign++;
994             j++;
995 
996             if (j == PULSE_MAX)
997                 break;
998         }
999     }
1000     subfrm->amp_index   = optim->amp_index;
1001     subfrm->grid_index  = optim->grid_index;
1002     subfrm->dirac_train = optim->dirac_train;
1003 }
1004 
1005 /**
1006  * Compute the fixed codebook excitation.
1007  *
1008  * @param buf          target vector
1009  * @param impulse_resp impulse response of the combined filter
1010  */
fcb_search(G723_1_ChannelContext *p, int16_t *impulse_resp, int16_t *buf, int index)1011 static void fcb_search(G723_1_ChannelContext *p, int16_t *impulse_resp,
1012                        int16_t *buf, int index)
1013 {
1014     FCBParam optim;
1015     int pulse_cnt = pulses[index];
1016     int i;
1017 
1018     optim.min_err = 1 << 30;
1019     get_fcb_param(&optim, impulse_resp, buf, pulse_cnt, SUBFRAME_LEN);
1020 
1021     if (p->pitch_lag[index >> 1] < SUBFRAME_LEN - 2) {
1022         get_fcb_param(&optim, impulse_resp, buf, pulse_cnt,
1023                       p->pitch_lag[index >> 1]);
1024     }
1025 
1026     /* Reconstruct the excitation */
1027     memset(buf, 0, sizeof(int16_t) * SUBFRAME_LEN);
1028     for (i = 0; i < pulse_cnt; i++)
1029         buf[optim.pulse_pos[i]] = optim.pulse_sign[i];
1030 
1031     pack_fcb_param(&p->subframe[index], &optim, buf, pulse_cnt);
1032 
1033     if (optim.dirac_train)
1034         ff_g723_1_gen_dirac_train(buf, p->pitch_lag[index >> 1]);
1035 }
1036 
1037 /**
1038  * Pack the frame parameters into output bitstream.
1039  *
1040  * @param frame output buffer
1041  * @param size  size of the buffer
1042  */
pack_bitstream(G723_1_ChannelContext *p, AVPacket *avpkt, int info_bits)1043 static void pack_bitstream(G723_1_ChannelContext *p, AVPacket *avpkt, int info_bits)
1044 {
1045     PutBitContext pb;
1046     int i, temp;
1047 
1048     init_put_bits(&pb, avpkt->data, avpkt->size);
1049 
1050     put_bits(&pb, 2, info_bits);
1051 
1052     put_bits(&pb, 8, p->lsp_index[2]);
1053     put_bits(&pb, 8, p->lsp_index[1]);
1054     put_bits(&pb, 8, p->lsp_index[0]);
1055 
1056     put_bits(&pb, 7, p->pitch_lag[0] - PITCH_MIN);
1057     put_bits(&pb, 2, p->subframe[1].ad_cb_lag);
1058     put_bits(&pb, 7, p->pitch_lag[1] - PITCH_MIN);
1059     put_bits(&pb, 2, p->subframe[3].ad_cb_lag);
1060 
1061     /* Write 12 bit combined gain */
1062     for (i = 0; i < SUBFRAMES; i++) {
1063         temp = p->subframe[i].ad_cb_gain * GAIN_LEVELS +
1064                p->subframe[i].amp_index;
1065         if (p->cur_rate == RATE_6300)
1066             temp += p->subframe[i].dirac_train << 11;
1067         put_bits(&pb, 12, temp);
1068     }
1069 
1070     put_bits(&pb, 1, p->subframe[0].grid_index);
1071     put_bits(&pb, 1, p->subframe[1].grid_index);
1072     put_bits(&pb, 1, p->subframe[2].grid_index);
1073     put_bits(&pb, 1, p->subframe[3].grid_index);
1074 
1075     if (p->cur_rate == RATE_6300) {
1076         put_bits(&pb, 1, 0); /* reserved bit */
1077 
1078         /* Write 13 bit combined position index */
1079         temp = (p->subframe[0].pulse_pos >> 16) * 810 +
1080                (p->subframe[1].pulse_pos >> 14) *  90 +
1081                (p->subframe[2].pulse_pos >> 16) *   9 +
1082                (p->subframe[3].pulse_pos >> 14);
1083         put_bits(&pb, 13, temp);
1084 
1085         put_bits(&pb, 16, p->subframe[0].pulse_pos & 0xffff);
1086         put_bits(&pb, 14, p->subframe[1].pulse_pos & 0x3fff);
1087         put_bits(&pb, 16, p->subframe[2].pulse_pos & 0xffff);
1088         put_bits(&pb, 14, p->subframe[3].pulse_pos & 0x3fff);
1089 
1090         put_bits(&pb, 6, p->subframe[0].pulse_sign);
1091         put_bits(&pb, 5, p->subframe[1].pulse_sign);
1092         put_bits(&pb, 6, p->subframe[2].pulse_sign);
1093         put_bits(&pb, 5, p->subframe[3].pulse_sign);
1094     }
1095 
1096     flush_put_bits(&pb);
1097 }
1098 
g723_1_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)1099 static int g723_1_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
1100                                const AVFrame *frame, int *got_packet_ptr)
1101 {
1102     G723_1_Context *s = avctx->priv_data;
1103     G723_1_ChannelContext *p = &s->ch[0];
1104     int16_t unq_lpc[LPC_ORDER * SUBFRAMES];
1105     int16_t qnt_lpc[LPC_ORDER * SUBFRAMES];
1106     int16_t cur_lsp[LPC_ORDER];
1107     int16_t weighted_lpc[LPC_ORDER * SUBFRAMES << 1];
1108     int16_t vector[FRAME_LEN + PITCH_MAX];
1109     int offset, ret, i, j, info_bits = 0;
1110     int16_t *in, *start;
1111     HFParam hf[4];
1112 
1113     /* duplicate input */
1114     start = in = av_memdup(frame->data[0], frame->nb_samples * sizeof(int16_t));
1115     if (!in)
1116         return AVERROR(ENOMEM);
1117 
1118     highpass_filter(in, &p->hpf_fir_mem, &p->hpf_iir_mem);
1119 
1120     memcpy(vector, p->prev_data, HALF_FRAME_LEN * sizeof(int16_t));
1121     memcpy(vector + HALF_FRAME_LEN, in, FRAME_LEN * sizeof(int16_t));
1122 
1123     comp_lpc_coeff(vector, unq_lpc);
1124     lpc2lsp(&unq_lpc[LPC_ORDER * 3], p->prev_lsp, cur_lsp);
1125     lsp_quantize(p->lsp_index, cur_lsp, p->prev_lsp);
1126 
1127     /* Update memory */
1128     memcpy(vector + LPC_ORDER, p->prev_data + SUBFRAME_LEN,
1129            sizeof(int16_t) * SUBFRAME_LEN);
1130     memcpy(vector + LPC_ORDER + SUBFRAME_LEN, in,
1131            sizeof(int16_t) * (HALF_FRAME_LEN + SUBFRAME_LEN));
1132     memcpy(p->prev_data, in + HALF_FRAME_LEN,
1133            sizeof(int16_t) * HALF_FRAME_LEN);
1134     memcpy(in, vector + LPC_ORDER, sizeof(int16_t) * FRAME_LEN);
1135 
1136     perceptual_filter(p, weighted_lpc, unq_lpc, vector);
1137 
1138     memcpy(in, vector + LPC_ORDER, sizeof(int16_t) * FRAME_LEN);
1139     memcpy(vector, p->prev_weight_sig, sizeof(int16_t) * PITCH_MAX);
1140     memcpy(vector + PITCH_MAX, in, sizeof(int16_t) * FRAME_LEN);
1141 
1142     ff_g723_1_scale_vector(vector, vector, FRAME_LEN + PITCH_MAX);
1143 
1144     p->pitch_lag[0] = estimate_pitch(vector, PITCH_MAX);
1145     p->pitch_lag[1] = estimate_pitch(vector, PITCH_MAX + HALF_FRAME_LEN);
1146 
1147     for (i = PITCH_MAX, j = 0; j < SUBFRAMES; i += SUBFRAME_LEN, j++)
1148         comp_harmonic_coeff(vector + i, p->pitch_lag[j >> 1], hf + j);
1149 
1150     memcpy(vector, p->prev_weight_sig, sizeof(int16_t) * PITCH_MAX);
1151     memcpy(vector + PITCH_MAX, in, sizeof(int16_t) * FRAME_LEN);
1152     memcpy(p->prev_weight_sig, vector + FRAME_LEN, sizeof(int16_t) * PITCH_MAX);
1153 
1154     for (i = 0, j = 0; j < SUBFRAMES; i += SUBFRAME_LEN, j++)
1155         harmonic_filter(hf + j, vector + PITCH_MAX + i, in + i);
1156 
1157     ff_g723_1_inverse_quant(cur_lsp, p->prev_lsp, p->lsp_index, 0);
1158     ff_g723_1_lsp_interpolate(qnt_lpc, cur_lsp, p->prev_lsp);
1159 
1160     memcpy(p->prev_lsp, cur_lsp, sizeof(int16_t) * LPC_ORDER);
1161 
1162     offset = 0;
1163     for (i = 0; i < SUBFRAMES; i++) {
1164         int16_t impulse_resp[SUBFRAME_LEN];
1165         int16_t residual[SUBFRAME_LEN + PITCH_ORDER - 1];
1166         int16_t flt_in[SUBFRAME_LEN];
1167         int16_t zero[LPC_ORDER], fir[LPC_ORDER], iir[LPC_ORDER];
1168 
1169         /**
1170          * Compute the combined impulse response of the synthesis filter,
1171          * formant perceptual weighting filter and harmonic noise shaping filter
1172          */
1173         memset(zero, 0, sizeof(int16_t) * LPC_ORDER);
1174         memset(vector, 0, sizeof(int16_t) * PITCH_MAX);
1175         memset(flt_in, 0, sizeof(int16_t) * SUBFRAME_LEN);
1176 
1177         flt_in[0] = 1 << 13; /* Unit impulse */
1178         synth_percept_filter(qnt_lpc + offset, weighted_lpc + (offset << 1),
1179                              zero, zero, flt_in, vector + PITCH_MAX, 1);
1180         harmonic_filter(hf + i, vector + PITCH_MAX, impulse_resp);
1181 
1182         /* Compute the combined zero input response */
1183         flt_in[0] = 0;
1184         memcpy(fir, p->perf_fir_mem, sizeof(int16_t) * LPC_ORDER);
1185         memcpy(iir, p->perf_iir_mem, sizeof(int16_t) * LPC_ORDER);
1186 
1187         synth_percept_filter(qnt_lpc + offset, weighted_lpc + (offset << 1),
1188                              fir, iir, flt_in, vector + PITCH_MAX, 0);
1189         memcpy(vector, p->harmonic_mem, sizeof(int16_t) * PITCH_MAX);
1190         harmonic_noise_sub(hf + i, vector + PITCH_MAX, in);
1191 
1192         acb_search(p, residual, impulse_resp, in, i);
1193         ff_g723_1_gen_acb_excitation(residual, p->prev_excitation,
1194                                      p->pitch_lag[i >> 1], &p->subframe[i],
1195                                      p->cur_rate);
1196         sub_acb_contrib(residual, impulse_resp, in);
1197 
1198         fcb_search(p, impulse_resp, in, i);
1199 
1200         /* Reconstruct the excitation */
1201         ff_g723_1_gen_acb_excitation(impulse_resp, p->prev_excitation,
1202                                      p->pitch_lag[i >> 1], &p->subframe[i],
1203                                      RATE_6300);
1204 
1205         memmove(p->prev_excitation, p->prev_excitation + SUBFRAME_LEN,
1206                 sizeof(int16_t) * (PITCH_MAX - SUBFRAME_LEN));
1207         for (j = 0; j < SUBFRAME_LEN; j++)
1208             in[j] = av_clip_int16((in[j] << 1) + impulse_resp[j]);
1209         memcpy(p->prev_excitation + PITCH_MAX - SUBFRAME_LEN, in,
1210                sizeof(int16_t) * SUBFRAME_LEN);
1211 
1212         /* Update filter memories */
1213         synth_percept_filter(qnt_lpc + offset, weighted_lpc + (offset << 1),
1214                              p->perf_fir_mem, p->perf_iir_mem,
1215                              in, vector + PITCH_MAX, 0);
1216         memmove(p->harmonic_mem, p->harmonic_mem + SUBFRAME_LEN,
1217                 sizeof(int16_t) * (PITCH_MAX - SUBFRAME_LEN));
1218         memcpy(p->harmonic_mem + PITCH_MAX - SUBFRAME_LEN, vector + PITCH_MAX,
1219                sizeof(int16_t) * SUBFRAME_LEN);
1220 
1221         in     += SUBFRAME_LEN;
1222         offset += LPC_ORDER;
1223     }
1224 
1225     av_free(start);
1226 
1227     ret = ff_get_encode_buffer(avctx, avpkt, frame_size[info_bits], 0);
1228     if (ret < 0)
1229         return ret;
1230 
1231     *got_packet_ptr = 1;
1232     pack_bitstream(p, avpkt, info_bits);
1233     return 0;
1234 }
1235 
1236 static const FFCodecDefault defaults[] = {
1237     { "b", "6300" },
1238     { NULL },
1239 };
1240 
1241 const FFCodec ff_g723_1_encoder = {
1242     .p.name         = "g723_1",
1243     .p.long_name    = NULL_IF_CONFIG_SMALL("G.723.1"),
1244     .p.type         = AVMEDIA_TYPE_AUDIO,
1245     .p.id           = AV_CODEC_ID_G723_1,
1246     .p.capabilities = AV_CODEC_CAP_DR1,
1247     .priv_data_size = sizeof(G723_1_Context),
1248     .init           = g723_1_encode_init,
1249     FF_CODEC_ENCODE_CB(g723_1_encode_frame),
1250     .defaults       = defaults,
1251     .p.sample_fmts  = (const enum AVSampleFormat[]) {
1252         AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE
1253     },
1254     .p.ch_layouts   = (const AVChannelLayout[]){
1255         AV_CHANNEL_LAYOUT_MONO, { 0 }
1256     },
1257     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
1258 };
1259