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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 "g723_1.h"
38 #include "internal.h"
39 
40 #define BITSTREAM_WRITER_LE
41 #include "put_bits.h"
42 
43 /**
44  * Hamming window coefficients scaled by 2^15
45  */
46 static const int16_t hamming_window[LPC_FRAME] = {
47      2621,  2631,  2659,  2705,  2770,  2853,  2955,  3074,  3212,  3367,
48      3541,  3731,  3939,  4164,  4405,  4663,  4937,  5226,  5531,  5851,
49      6186,  6534,  6897,  7273,  7661,  8062,  8475,  8899,  9334,  9780,
50     10235, 10699, 11172, 11653, 12141, 12636, 13138, 13645, 14157, 14673,
51     15193, 15716, 16242, 16769, 17298, 17827, 18356, 18884, 19411, 19935,
52     20457, 20975, 21489, 21999, 22503, 23002, 23494, 23978, 24455, 24924,
53     25384, 25834, 26274, 26704, 27122, 27529, 27924, 28306, 28675, 29031,
54     29373, 29700, 30012, 30310, 30592, 30857, 31107, 31340, 31557, 31756,
55     31938, 32102, 32249, 32377, 32488, 32580, 32654, 32710, 32747, 32766,
56     32766, 32747, 32710, 32654, 32580, 32488, 32377, 32249, 32102, 31938,
57     31756, 31557, 31340, 31107, 30857, 30592, 30310, 30012, 29700, 29373,
58     29031, 28675, 28306, 27924, 27529, 27122, 26704, 26274, 25834, 25384,
59     24924, 24455, 23978, 23494, 23002, 22503, 21999, 21489, 20975, 20457,
60     19935, 19411, 18884, 18356, 17827, 17298, 16769, 16242, 15716, 15193,
61     14673, 14157, 13645, 13138, 12636, 12141, 11653, 11172, 10699, 10235,
62      9780, 9334,   8899,  8475,  8062,  7661,  7273,  6897,  6534,  6186,
63      5851, 5531,   5226,  4937,  4663,  4405,  4164,  3939,  3731,  3541,
64      3367, 3212,   3074,  2955,  2853,  2770,  2705,  2659,  2631,  2621
65 };
66 
67 /**
68  * Binomial window coefficients scaled by 2^15
69  */
70 static const int16_t binomial_window[LPC_ORDER] = {
71     32749, 32695, 32604, 32477, 32315, 32118, 31887, 31622, 31324, 30995
72 };
73 
74 /**
75  * 0.994^i scaled by 2^15
76  */
77 static const int16_t bandwidth_expand[LPC_ORDER] = {
78     32571, 32376, 32182, 31989, 31797, 31606, 31416, 31228, 31040, 30854
79 };
80 
81 /**
82  * 0.5^i scaled by 2^15
83  */
84 static const int16_t percept_flt_tbl[2][LPC_ORDER] = {
85     /* Zero part */
86     {29491, 26542, 23888, 21499, 19349, 17414, 15673, 14106, 12695, 11425},
87     /* Pole part */
88     {16384,  8192,  4096,  2048,  1024,   512,   256,   128,    64,    32}
89 };
90 
g723_1_encode_init(AVCodecContext * avctx)91 static av_cold int g723_1_encode_init(AVCodecContext *avctx)
92 {
93     G723_1_Context *s = avctx->priv_data;
94     G723_1_ChannelContext *p = &s->ch[0];
95 
96     if (avctx->sample_rate != 8000) {
97         av_log(avctx, AV_LOG_ERROR, "Only 8000Hz sample rate supported\n");
98         return AVERROR(EINVAL);
99     }
100 
101     if (avctx->channels != 1) {
102         av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
103         return AVERROR(EINVAL);
104     }
105 
106     if (avctx->bit_rate == 6300) {
107         p->cur_rate = RATE_6300;
108     } else if (avctx->bit_rate == 5300) {
109         av_log(avctx, AV_LOG_ERROR, "Use bitrate 6300 instead of 5300.\n");
110         avpriv_report_missing_feature(avctx, "Bitrate 5300");
111         return AVERROR_PATCHWELCOME;
112     } else {
113         av_log(avctx, AV_LOG_ERROR, "Bitrate not supported, use 6300\n");
114         return AVERROR(EINVAL);
115     }
116     avctx->frame_size = 240;
117     memcpy(p->prev_lsp, dc_lsp, LPC_ORDER * sizeof(int16_t));
118 
119     return 0;
120 }
121 
122 /**
123  * Remove DC component from the input signal.
124  *
125  * @param buf input signal
126  * @param fir zero memory
127  * @param iir pole memory
128  */
highpass_filter(int16_t * buf,int16_t * fir,int * iir)129 static void highpass_filter(int16_t *buf, int16_t *fir, int *iir)
130 {
131     int i;
132     for (i = 0; i < FRAME_LEN; i++) {
133         *iir   = (buf[i] << 15) + ((-*fir) << 15) + MULL2(*iir, 0x7f00);
134         *fir   = buf[i];
135         buf[i] = av_clipl_int32((int64_t)*iir + (1 << 15)) >> 16;
136     }
137 }
138 
139 /**
140  * Estimate autocorrelation of the input vector.
141  *
142  * @param buf      input buffer
143  * @param autocorr autocorrelation coefficients vector
144  */
comp_autocorr(int16_t * buf,int16_t * autocorr)145 static void comp_autocorr(int16_t *buf, int16_t *autocorr)
146 {
147     int i, scale, temp;
148     int16_t vector[LPC_FRAME];
149 
150     ff_g723_1_scale_vector(vector, buf, LPC_FRAME);
151 
152     /* Apply the Hamming window */
153     for (i = 0; i < LPC_FRAME; i++)
154         vector[i] = (vector[i] * hamming_window[i] + (1 << 14)) >> 15;
155 
156     /* Compute the first autocorrelation coefficient */
157     temp = ff_dot_product(vector, vector, LPC_FRAME);
158 
159     /* Apply a white noise correlation factor of (1025/1024) */
160     temp += temp >> 10;
161 
162     /* Normalize */
163     scale       = ff_g723_1_normalize_bits(temp, 31);
164     autocorr[0] = av_clipl_int32((int64_t) (temp << scale) +
165                                  (1 << 15)) >> 16;
166 
167     /* Compute the remaining coefficients */
168     if (!autocorr[0]) {
169         memset(autocorr + 1, 0, LPC_ORDER * sizeof(int16_t));
170     } else {
171         for (i = 1; i <= LPC_ORDER; i++) {
172             temp        = ff_dot_product(vector, vector + i, LPC_FRAME - i);
173             temp        = MULL2((temp << scale), binomial_window[i - 1]);
174             autocorr[i] = av_clipl_int32((int64_t) temp + (1 << 15)) >> 16;
175         }
176     }
177 }
178 
179 /**
180  * Use Levinson-Durbin recursion to compute LPC coefficients from
181  * autocorrelation values.
182  *
183  * @param lpc      LPC coefficients vector
184  * @param autocorr autocorrelation coefficients vector
185  * @param error    prediction error
186  */
levinson_durbin(int16_t * lpc,int16_t * autocorr,int16_t error)187 static void levinson_durbin(int16_t *lpc, int16_t *autocorr, int16_t error)
188 {
189     int16_t vector[LPC_ORDER];
190     int16_t partial_corr;
191     int i, j, temp;
192 
193     memset(lpc, 0, LPC_ORDER * sizeof(int16_t));
194 
195     for (i = 0; i < LPC_ORDER; i++) {
196         /* Compute the partial correlation coefficient */
197         temp = 0;
198         for (j = 0; j < i; j++)
199             temp -= lpc[j] * autocorr[i - j - 1];
200         temp = ((autocorr[i] << 13) + temp) << 3;
201 
202         if (FFABS(temp) >= (error << 16))
203             break;
204 
205         partial_corr = temp / (error << 1);
206 
207         lpc[i] = av_clipl_int32((int64_t) (partial_corr << 14) +
208                                 (1 << 15)) >> 16;
209 
210         /* Update the prediction error */
211         temp  = MULL2(temp, partial_corr);
212         error = av_clipl_int32((int64_t) (error << 16) - temp +
213                                (1 << 15)) >> 16;
214 
215         memcpy(vector, lpc, i * sizeof(int16_t));
216         for (j = 0; j < i; j++) {
217             temp   = partial_corr * vector[i - j - 1] << 1;
218             lpc[j] = av_clipl_int32((int64_t) (lpc[j] << 16) - temp +
219                                     (1 << 15)) >> 16;
220         }
221     }
222 }
223 
224 /**
225  * Calculate LPC coefficients for the current frame.
226  *
227  * @param buf       current frame
228  * @param prev_data 2 trailing subframes of the previous frame
229  * @param lpc       LPC coefficients vector
230  */
comp_lpc_coeff(int16_t * buf,int16_t * lpc)231 static void comp_lpc_coeff(int16_t *buf, int16_t *lpc)
232 {
233     int16_t autocorr[(LPC_ORDER + 1) * SUBFRAMES];
234     int16_t *autocorr_ptr = autocorr;
235     int16_t *lpc_ptr      = lpc;
236     int i, j;
237 
238     for (i = 0, j = 0; j < SUBFRAMES; i += SUBFRAME_LEN, j++) {
239         comp_autocorr(buf + i, autocorr_ptr);
240         levinson_durbin(lpc_ptr, autocorr_ptr + 1, autocorr_ptr[0]);
241 
242         lpc_ptr      += LPC_ORDER;
243         autocorr_ptr += LPC_ORDER + 1;
244     }
245 }
246 
lpc2lsp(int16_t * lpc,int16_t * prev_lsp,int16_t * lsp)247 static void lpc2lsp(int16_t *lpc, int16_t *prev_lsp, int16_t *lsp)
248 {
249     int f[LPC_ORDER + 2]; ///< coefficients of the sum and difference
250                           ///< polynomials (F1, F2) ordered as
251                           ///< f1[0], f2[0], ...., f1[5], f2[5]
252 
253     int max, shift, cur_val, prev_val, count, p;
254     int i, j;
255     int64_t temp;
256 
257     /* Initialize f1[0] and f2[0] to 1 in Q25 */
258     for (i = 0; i < LPC_ORDER; i++)
259         lsp[i] = (lpc[i] * bandwidth_expand[i] + (1 << 14)) >> 15;
260 
261     /* Apply bandwidth expansion on the LPC coefficients */
262     f[0] = f[1] = 1 << 25;
263 
264     /* Compute the remaining coefficients */
265     for (i = 0; i < LPC_ORDER / 2; i++) {
266         /* f1 */
267         f[2 * i + 2] = -f[2 * i] - ((lsp[i] + lsp[LPC_ORDER - 1 - i]) << 12);
268         /* f2 */
269         f[2 * i + 3] = f[2 * i + 1] - ((lsp[i] - lsp[LPC_ORDER - 1 - i]) << 12);
270     }
271 
272     /* Divide f1[5] and f2[5] by 2 for use in polynomial evaluation */
273     f[LPC_ORDER]     >>= 1;
274     f[LPC_ORDER + 1] >>= 1;
275 
276     /* Normalize and shorten */
277     max = FFABS(f[0]);
278     for (i = 1; i < LPC_ORDER + 2; i++)
279         max = FFMAX(max, FFABS(f[i]));
280 
281     shift = ff_g723_1_normalize_bits(max, 31);
282 
283     for (i = 0; i < LPC_ORDER + 2; i++)
284         f[i] = av_clipl_int32((int64_t) (f[i] << shift) + (1 << 15)) >> 16;
285 
286     /**
287      * Evaluate F1 and F2 at uniform intervals of pi/256 along the
288      * unit circle and check for zero crossings.
289      */
290     p    = 0;
291     temp = 0;
292     for (i = 0; i <= LPC_ORDER / 2; i++)
293         temp += f[2 * i] * G723_1_COS_TAB_FIRST_ELEMENT;
294     prev_val = av_clipl_int32(temp << 1);
295     count    = 0;
296     for (i = 1; i < COS_TBL_SIZE / 2; i++) {
297         /* Evaluate */
298         temp = 0;
299         for (j = 0; j <= LPC_ORDER / 2; j++)
300             temp += f[LPC_ORDER - 2 * j + p] * ff_g723_1_cos_tab[i * j % COS_TBL_SIZE];
301         cur_val = av_clipl_int32(temp << 1);
302 
303         /* Check for sign change, indicating a zero crossing */
304         if ((cur_val ^ prev_val) < 0) {
305             int abs_cur  = FFABS(cur_val);
306             int abs_prev = FFABS(prev_val);
307             int sum      = abs_cur + abs_prev;
308 
309             shift        = ff_g723_1_normalize_bits(sum, 31);
310             sum        <<= shift;
311             abs_prev     = abs_prev << shift >> 8;
312             lsp[count++] = ((i - 1) << 7) + (abs_prev >> 1) / (sum >> 16);
313 
314             if (count == LPC_ORDER)
315                 break;
316 
317             /* Switch between sum and difference polynomials */
318             p ^= 1;
319 
320             /* Evaluate */
321             temp = 0;
322             for (j = 0; j <= LPC_ORDER / 2; j++)
323                 temp += f[LPC_ORDER - 2 * j + p] *
324                         ff_g723_1_cos_tab[i * j % COS_TBL_SIZE];
325             cur_val = av_clipl_int32(temp << 1);
326         }
327         prev_val = cur_val;
328     }
329 
330     if (count != LPC_ORDER)
331         memcpy(lsp, prev_lsp, LPC_ORDER * sizeof(int16_t));
332 }
333 
334 /**
335  * Quantize the current LSP subvector.
336  *
337  * @param num    band number
338  * @param offset offset of the current subvector in an LPC_ORDER vector
339  * @param size   size of the current subvector
340  */
341 #define get_index(num, offset, size)                                          \
342 {                                                                             \
343     int error, max = -1;                                                      \
344     int16_t temp[4];                                                          \
345     int i, j;                                                                 \
346                                                                               \
347     for (i = 0; i < LSP_CB_SIZE; i++) {                                       \
348         for (j = 0; j < size; j++){                                           \
349             temp[j] = (weight[j + (offset)] * ff_g723_1_lsp_band##num[i][j] + \
350                       (1 << 14)) >> 15;                                       \
351         }                                                                     \
352         error  = ff_g723_1_dot_product(lsp + (offset), temp, size) << 1;      \
353         error -= ff_g723_1_dot_product(ff_g723_1_lsp_band##num[i], temp, size); \
354         if (error > max) {                                                    \
355             max = error;                                                      \
356             lsp_index[num] = i;                                               \
357         }                                                                     \
358     }                                                                         \
359 }
360 
361 /**
362  * Vector quantize the LSP frequencies.
363  *
364  * @param lsp      the current lsp vector
365  * @param prev_lsp the previous lsp vector
366  */
lsp_quantize(uint8_t * lsp_index,int16_t * lsp,int16_t * prev_lsp)367 static void lsp_quantize(uint8_t *lsp_index, int16_t *lsp, int16_t *prev_lsp)
368 {
369     int16_t weight[LPC_ORDER];
370     int16_t min, max;
371     int shift, i;
372 
373     /* Calculate the VQ weighting vector */
374     weight[0]             = (1 << 20) / (lsp[1] - lsp[0]);
375     weight[LPC_ORDER - 1] = (1 << 20) /
376                             (lsp[LPC_ORDER - 1] - lsp[LPC_ORDER - 2]);
377 
378     for (i = 1; i < LPC_ORDER - 1; i++) {
379         min = FFMIN(lsp[i] - lsp[i - 1], lsp[i + 1] - lsp[i]);
380         if (min > 0x20)
381             weight[i] = (1 << 20) / min;
382         else
383             weight[i] = INT16_MAX;
384     }
385 
386     /* Normalize */
387     max = 0;
388     for (i = 0; i < LPC_ORDER; i++)
389         max = FFMAX(weight[i], max);
390 
391     shift = ff_g723_1_normalize_bits(max, 15);
392     for (i = 0; i < LPC_ORDER; i++) {
393         weight[i] <<= shift;
394     }
395 
396     /* Compute the VQ target vector */
397     for (i = 0; i < LPC_ORDER; i++) {
398         lsp[i] -= dc_lsp[i] +
399                   (((prev_lsp[i] - dc_lsp[i]) * 12288 + (1 << 14)) >> 15);
400     }
401 
402     get_index(0, 0, 3);
403     get_index(1, 3, 3);
404     get_index(2, 6, 4);
405 }
406 
407 /**
408  * Perform IIR filtering.
409  *
410  * @param fir_coef FIR coefficients
411  * @param iir_coef IIR coefficients
412  * @param src      source vector
413  * @param dest     destination vector
414  */
iir_filter(int16_t * fir_coef,int16_t * iir_coef,int16_t * src,int16_t * dest)415 static void iir_filter(int16_t *fir_coef, int16_t *iir_coef,
416                        int16_t *src, int16_t *dest)
417 {
418     int m, n;
419 
420     for (m = 0; m < SUBFRAME_LEN; m++) {
421         int64_t filter = 0;
422         for (n = 1; n <= LPC_ORDER; n++) {
423             filter -= fir_coef[n - 1] * src[m - n] -
424                       iir_coef[n - 1] * dest[m - n];
425         }
426 
427         dest[m] = av_clipl_int32((src[m] << 16) + (filter << 3) +
428                                  (1 << 15)) >> 16;
429     }
430 }
431 
432 /**
433  * Apply the formant perceptual weighting filter.
434  *
435  * @param flt_coef filter coefficients
436  * @param unq_lpc  unquantized lpc vector
437  */
perceptual_filter(G723_1_ChannelContext * p,int16_t * flt_coef,int16_t * unq_lpc,int16_t * buf)438 static void perceptual_filter(G723_1_ChannelContext *p, int16_t *flt_coef,
439                               int16_t *unq_lpc, int16_t *buf)
440 {
441     int16_t vector[FRAME_LEN + LPC_ORDER];
442     int i, j, k, l = 0;
443 
444     memcpy(buf, p->iir_mem, sizeof(int16_t) * LPC_ORDER);
445     memcpy(vector, p->fir_mem, sizeof(int16_t) * LPC_ORDER);
446     memcpy(vector + LPC_ORDER, buf + LPC_ORDER, sizeof(int16_t) * FRAME_LEN);
447 
448     for (i = LPC_ORDER, j = 0; j < SUBFRAMES; i += SUBFRAME_LEN, j++) {
449         for (k = 0; k < LPC_ORDER; k++) {
450             flt_coef[k + 2 * l] = (unq_lpc[k + l] * percept_flt_tbl[0][k] +
451                                    (1 << 14)) >> 15;
452             flt_coef[k + 2 * l + LPC_ORDER] = (unq_lpc[k + l] *
453                                                percept_flt_tbl[1][k] +
454                                                (1 << 14)) >> 15;
455         }
456         iir_filter(flt_coef + 2 * l, flt_coef + 2 * l + LPC_ORDER,
457                    vector + i, buf + i);
458         l += LPC_ORDER;
459     }
460     memcpy(p->iir_mem, buf + FRAME_LEN, sizeof(int16_t) * LPC_ORDER);
461     memcpy(p->fir_mem, vector + FRAME_LEN, sizeof(int16_t) * LPC_ORDER);
462 }
463 
464 /**
465  * Estimate the open loop pitch period.
466  *
467  * @param buf   perceptually weighted speech
468  * @param start estimation is carried out from this position
469  */
estimate_pitch(int16_t * buf,int start)470 static int estimate_pitch(int16_t *buf, int start)
471 {
472     int max_exp = 32;
473     int max_ccr = 0x4000;
474     int max_eng = 0x7fff;
475     int index   = PITCH_MIN;
476     int offset  = start - PITCH_MIN + 1;
477 
478     int ccr, eng, orig_eng, ccr_eng, exp;
479     int diff, temp;
480 
481     int i;
482 
483     orig_eng = ff_dot_product(buf + offset, buf + offset, HALF_FRAME_LEN);
484 
485     for (i = PITCH_MIN; i <= PITCH_MAX - 3; i++) {
486         offset--;
487 
488         /* Update energy and compute correlation */
489         orig_eng += buf[offset] * buf[offset] -
490                     buf[offset + HALF_FRAME_LEN] * buf[offset + HALF_FRAME_LEN];
491         ccr = ff_dot_product(buf + start, buf + offset, HALF_FRAME_LEN);
492         if (ccr <= 0)
493             continue;
494 
495         /* Split into mantissa and exponent to maintain precision */
496         exp   = ff_g723_1_normalize_bits(ccr, 31);
497         ccr   = av_clipl_int32((int64_t) (ccr << exp) + (1 << 15)) >> 16;
498         exp <<= 1;
499         ccr  *= ccr;
500         temp  = ff_g723_1_normalize_bits(ccr, 31);
501         ccr   = ccr << temp >> 16;
502         exp  += temp;
503 
504         temp = ff_g723_1_normalize_bits(orig_eng, 31);
505         eng  = av_clipl_int32((int64_t) (orig_eng << temp) + (1 << 15)) >> 16;
506         exp -= temp;
507 
508         if (ccr >= eng) {
509             exp--;
510             ccr >>= 1;
511         }
512         if (exp > max_exp)
513             continue;
514 
515         if (exp + 1 < max_exp)
516             goto update;
517 
518         /* Equalize exponents before comparison */
519         if (exp + 1 == max_exp)
520             temp = max_ccr >> 1;
521         else
522             temp = max_ccr;
523         ccr_eng = ccr * max_eng;
524         diff    = ccr_eng - eng * temp;
525         if (diff > 0 && (i - index < PITCH_MIN || diff > ccr_eng >> 2)) {
526 update:
527             index   = i;
528             max_exp = exp;
529             max_ccr = ccr;
530             max_eng = eng;
531         }
532     }
533     return index;
534 }
535 
536 /**
537  * Compute harmonic noise filter parameters.
538  *
539  * @param buf       perceptually weighted speech
540  * @param pitch_lag open loop pitch period
541  * @param hf        harmonic filter parameters
542  */
comp_harmonic_coeff(int16_t * buf,int16_t pitch_lag,HFParam * hf)543 static void comp_harmonic_coeff(int16_t *buf, int16_t pitch_lag, HFParam *hf)
544 {
545     int ccr, eng, max_ccr, max_eng;
546     int exp, max, diff;
547     int energy[15];
548     int i, j;
549 
550     for (i = 0, j = pitch_lag - 3; j <= pitch_lag + 3; i++, j++) {
551         /* Compute residual energy */
552         energy[i << 1] = ff_dot_product(buf - j, buf - j, SUBFRAME_LEN);
553         /* Compute correlation */
554         energy[(i << 1) + 1] = ff_dot_product(buf, buf - j, SUBFRAME_LEN);
555     }
556 
557     /* Compute target energy */
558     energy[14] = ff_dot_product(buf, buf, SUBFRAME_LEN);
559 
560     /* Normalize */
561     max = 0;
562     for (i = 0; i < 15; i++)
563         max = FFMAX(max, FFABS(energy[i]));
564 
565     exp = ff_g723_1_normalize_bits(max, 31);
566     for (i = 0; i < 15; i++) {
567         energy[i] = av_clipl_int32((int64_t)(energy[i] << exp) +
568                                    (1 << 15)) >> 16;
569     }
570 
571     hf->index = -1;
572     hf->gain  =  0;
573     max_ccr   =  1;
574     max_eng   =  0x7fff;
575 
576     for (i = 0; i <= 6; i++) {
577         eng = energy[i << 1];
578         ccr = energy[(i << 1) + 1];
579 
580         if (ccr <= 0)
581             continue;
582 
583         ccr  = (ccr * ccr + (1 << 14)) >> 15;
584         diff = ccr * max_eng - eng * max_ccr;
585         if (diff > 0) {
586             max_ccr   = ccr;
587             max_eng   = eng;
588             hf->index = i;
589         }
590     }
591 
592     if (hf->index == -1) {
593         hf->index = pitch_lag;
594         return;
595     }
596 
597     eng = energy[14] * max_eng;
598     eng = (eng >> 2) + (eng >> 3);
599     ccr = energy[(hf->index << 1) + 1] * energy[(hf->index << 1) + 1];
600     if (eng < ccr) {
601         eng = energy[(hf->index << 1) + 1];
602 
603         if (eng >= max_eng)
604             hf->gain = 0x2800;
605         else
606             hf->gain = ((eng << 15) / max_eng * 0x2800 + (1 << 14)) >> 15;
607     }
608     hf->index += pitch_lag - 3;
609 }
610 
611 /**
612  * Apply the harmonic noise shaping filter.
613  *
614  * @param hf filter parameters
615  */
harmonic_filter(HFParam * hf,const int16_t * src,int16_t * dest)616 static void harmonic_filter(HFParam *hf, const int16_t *src, int16_t *dest)
617 {
618     int i;
619 
620     for (i = 0; i < SUBFRAME_LEN; i++) {
621         int64_t temp = hf->gain * src[i - hf->index] << 1;
622         dest[i] = av_clipl_int32((src[i] << 16) - temp + (1 << 15)) >> 16;
623     }
624 }
625 
harmonic_noise_sub(HFParam * hf,const int16_t * src,int16_t * dest)626 static void harmonic_noise_sub(HFParam *hf, const int16_t *src, int16_t *dest)
627 {
628     int i;
629     for (i = 0; i < SUBFRAME_LEN; i++) {
630         int64_t temp = hf->gain * src[i - hf->index] << 1;
631         dest[i] = av_clipl_int32(((dest[i] - src[i]) << 16) + temp +
632                                  (1 << 15)) >> 16;
633     }
634 }
635 
636 /**
637  * Combined synthesis and formant perceptual weighting filer.
638  *
639  * @param qnt_lpc  quantized lpc coefficients
640  * @param perf_lpc perceptual filter coefficients
641  * @param perf_fir perceptual filter fir memory
642  * @param perf_iir perceptual filter iir memory
643  * @param scale    the filter output will be scaled by 2^scale
644  */
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)645 static void synth_percept_filter(int16_t *qnt_lpc, int16_t *perf_lpc,
646                                  int16_t *perf_fir, int16_t *perf_iir,
647                                  const int16_t *src, int16_t *dest, int scale)
648 {
649     int i, j;
650     int16_t buf_16[SUBFRAME_LEN + LPC_ORDER];
651     int64_t buf[SUBFRAME_LEN];
652 
653     int16_t *bptr_16 = buf_16 + LPC_ORDER;
654 
655     memcpy(buf_16, perf_fir, sizeof(int16_t) * LPC_ORDER);
656     memcpy(dest - LPC_ORDER, perf_iir, sizeof(int16_t) * LPC_ORDER);
657 
658     for (i = 0; i < SUBFRAME_LEN; i++) {
659         int64_t temp = 0;
660         for (j = 1; j <= LPC_ORDER; j++)
661             temp -= qnt_lpc[j - 1] * bptr_16[i - j];
662 
663         buf[i]     = (src[i] << 15) + (temp << 3);
664         bptr_16[i] = av_clipl_int32(buf[i] + (1 << 15)) >> 16;
665     }
666 
667     for (i = 0; i < SUBFRAME_LEN; i++) {
668         int64_t fir = 0, iir = 0;
669         for (j = 1; j <= LPC_ORDER; j++) {
670             fir -= perf_lpc[j - 1] * bptr_16[i - j];
671             iir += perf_lpc[j + LPC_ORDER - 1] * dest[i - j];
672         }
673         dest[i] = av_clipl_int32(((buf[i] + (fir << 3)) << scale) + (iir << 3) +
674                                  (1 << 15)) >> 16;
675     }
676     memcpy(perf_fir, buf_16 + SUBFRAME_LEN, sizeof(int16_t) * LPC_ORDER);
677     memcpy(perf_iir, dest + SUBFRAME_LEN - LPC_ORDER,
678            sizeof(int16_t) * LPC_ORDER);
679 }
680 
681 /**
682  * Compute the adaptive codebook contribution.
683  *
684  * @param buf   input signal
685  * @param index the current subframe index
686  */
acb_search(G723_1_ChannelContext * p,int16_t * residual,int16_t * impulse_resp,const int16_t * buf,int index)687 static void acb_search(G723_1_ChannelContext *p, int16_t *residual,
688                        int16_t *impulse_resp, const int16_t *buf,
689                        int index)
690 {
691     int16_t flt_buf[PITCH_ORDER][SUBFRAME_LEN];
692 
693     const int16_t *cb_tbl = ff_g723_1_adaptive_cb_gain85;
694 
695     int ccr_buf[PITCH_ORDER * SUBFRAMES << 2];
696 
697     int pitch_lag = p->pitch_lag[index >> 1];
698     int acb_lag   = 1;
699     int acb_gain  = 0;
700     int odd_frame = index & 1;
701     int iter      = 3 + odd_frame;
702     int count     = 0;
703     int tbl_size  = 85;
704 
705     int i, j, k, l, max;
706     int64_t temp;
707 
708     if (!odd_frame) {
709         if (pitch_lag == PITCH_MIN)
710             pitch_lag++;
711         else
712             pitch_lag = FFMIN(pitch_lag, PITCH_MAX - 5);
713     }
714 
715     for (i = 0; i < iter; i++) {
716         ff_g723_1_get_residual(residual, p->prev_excitation, pitch_lag + i - 1);
717 
718         for (j = 0; j < SUBFRAME_LEN; j++) {
719             temp = 0;
720             for (k = 0; k <= j; k++)
721                 temp += residual[PITCH_ORDER - 1 + k] * impulse_resp[j - k];
722             flt_buf[PITCH_ORDER - 1][j] = av_clipl_int32((temp << 1) +
723                                                          (1 << 15)) >> 16;
724         }
725 
726         for (j = PITCH_ORDER - 2; j >= 0; j--) {
727             flt_buf[j][0] = ((residual[j] << 13) + (1 << 14)) >> 15;
728             for (k = 1; k < SUBFRAME_LEN; k++) {
729                 temp = (flt_buf[j + 1][k - 1] << 15) +
730                        residual[j] * impulse_resp[k];
731                 flt_buf[j][k] = av_clipl_int32((temp << 1) + (1 << 15)) >> 16;
732             }
733         }
734 
735         /* Compute crosscorrelation with the signal */
736         for (j = 0; j < PITCH_ORDER; j++) {
737             temp             = ff_dot_product(buf, flt_buf[j], SUBFRAME_LEN);
738             ccr_buf[count++] = av_clipl_int32(temp << 1);
739         }
740 
741         /* Compute energies */
742         for (j = 0; j < PITCH_ORDER; j++) {
743             ccr_buf[count++] = ff_g723_1_dot_product(flt_buf[j], flt_buf[j],
744                                                      SUBFRAME_LEN);
745         }
746 
747         for (j = 1; j < PITCH_ORDER; j++) {
748             for (k = 0; k < j; k++) {
749                 temp             = ff_dot_product(flt_buf[j], flt_buf[k], SUBFRAME_LEN);
750                 ccr_buf[count++] = av_clipl_int32(temp << 2);
751             }
752         }
753     }
754 
755     /* Normalize and shorten */
756     max = 0;
757     for (i = 0; i < 20 * iter; i++)
758         max = FFMAX(max, FFABS(ccr_buf[i]));
759 
760     temp = ff_g723_1_normalize_bits(max, 31);
761 
762     for (i = 0; i < 20 * iter; i++)
763         ccr_buf[i] = av_clipl_int32((int64_t) (ccr_buf[i] << temp) +
764                                     (1 << 15)) >> 16;
765 
766     max = 0;
767     for (i = 0; i < iter; i++) {
768         /* Select quantization table */
769         if (!odd_frame && pitch_lag + i - 1 >= SUBFRAME_LEN - 2 ||
770             odd_frame && pitch_lag >= SUBFRAME_LEN - 2) {
771             cb_tbl   = ff_g723_1_adaptive_cb_gain170;
772             tbl_size = 170;
773         }
774 
775         for (j = 0, k = 0; j < tbl_size; j++, k += 20) {
776             temp = 0;
777             for (l = 0; l < 20; l++)
778                 temp += ccr_buf[20 * i + l] * cb_tbl[k + l];
779             temp = av_clipl_int32(temp);
780 
781             if (temp > max) {
782                 max      = temp;
783                 acb_gain = j;
784                 acb_lag  = i;
785             }
786         }
787     }
788 
789     if (!odd_frame) {
790         pitch_lag += acb_lag - 1;
791         acb_lag    = 1;
792     }
793 
794     p->pitch_lag[index >> 1]      = pitch_lag;
795     p->subframe[index].ad_cb_lag  = acb_lag;
796     p->subframe[index].ad_cb_gain = acb_gain;
797 }
798 
799 /**
800  * Subtract the adaptive codebook contribution from the input
801  * to obtain the residual.
802  *
803  * @param buf target vector
804  */
sub_acb_contrib(const int16_t * residual,const int16_t * impulse_resp,int16_t * buf)805 static void sub_acb_contrib(const int16_t *residual, const int16_t *impulse_resp,
806                             int16_t *buf)
807 {
808     int i, j;
809     /* Subtract adaptive CB contribution to obtain the residual */
810     for (i = 0; i < SUBFRAME_LEN; i++) {
811         int64_t temp = buf[i] << 14;
812         for (j = 0; j <= i; j++)
813             temp -= residual[j] * impulse_resp[i - j];
814 
815         buf[i] = av_clipl_int32((temp << 2) + (1 << 15)) >> 16;
816     }
817 }
818 
819 /**
820  * Quantize the residual signal using the fixed codebook (MP-MLQ).
821  *
822  * @param optim optimized fixed codebook parameters
823  * @param buf   excitation vector
824  */
get_fcb_param(FCBParam * optim,int16_t * impulse_resp,int16_t * buf,int pulse_cnt,int pitch_lag)825 static void get_fcb_param(FCBParam *optim, int16_t *impulse_resp,
826                           int16_t *buf, int pulse_cnt, int pitch_lag)
827 {
828     FCBParam param;
829     int16_t impulse_r[SUBFRAME_LEN];
830     int16_t temp_corr[SUBFRAME_LEN];
831     int16_t impulse_corr[SUBFRAME_LEN];
832 
833     int ccr1[SUBFRAME_LEN];
834     int ccr2[SUBFRAME_LEN];
835     int amp, err, max, max_amp_index, min, scale, i, j, k, l;
836 
837     int64_t temp;
838 
839     /* Update impulse response */
840     memcpy(impulse_r, impulse_resp, sizeof(int16_t) * SUBFRAME_LEN);
841     param.dirac_train = 0;
842     if (pitch_lag < SUBFRAME_LEN - 2) {
843         param.dirac_train = 1;
844         ff_g723_1_gen_dirac_train(impulse_r, pitch_lag);
845     }
846 
847     for (i = 0; i < SUBFRAME_LEN; i++)
848         temp_corr[i] = impulse_r[i] >> 1;
849 
850     /* Compute impulse response autocorrelation */
851     temp = ff_g723_1_dot_product(temp_corr, temp_corr, SUBFRAME_LEN);
852 
853     scale           = ff_g723_1_normalize_bits(temp, 31);
854     impulse_corr[0] = av_clipl_int32((temp << scale) + (1 << 15)) >> 16;
855 
856     for (i = 1; i < SUBFRAME_LEN; i++) {
857         temp = ff_g723_1_dot_product(temp_corr + i, temp_corr,
858                                      SUBFRAME_LEN - i);
859         impulse_corr[i] = av_clipl_int32((temp << scale) + (1 << 15)) >> 16;
860     }
861 
862     /* Compute crosscorrelation of impulse response with residual signal */
863     scale -= 4;
864     for (i = 0; i < SUBFRAME_LEN; i++) {
865         temp = ff_g723_1_dot_product(buf + i, impulse_r, SUBFRAME_LEN - i);
866         if (scale < 0)
867             ccr1[i] = temp >> -scale;
868         else
869             ccr1[i] = av_clipl_int32(temp << scale);
870     }
871 
872     /* Search loop */
873     for (i = 0; i < GRID_SIZE; i++) {
874         /* Maximize the crosscorrelation */
875         max = 0;
876         for (j = i; j < SUBFRAME_LEN; j += GRID_SIZE) {
877             temp = FFABS(ccr1[j]);
878             if (temp >= max) {
879                 max                = temp;
880                 param.pulse_pos[0] = j;
881             }
882         }
883 
884         /* Quantize the gain (max crosscorrelation/impulse_corr[0]) */
885         amp           = max;
886         min           = 1 << 30;
887         max_amp_index = GAIN_LEVELS - 2;
888         for (j = max_amp_index; j >= 2; j--) {
889             temp = av_clipl_int32((int64_t) ff_g723_1_fixed_cb_gain[j] *
890                                   impulse_corr[0] << 1);
891             temp = FFABS(temp - amp);
892             if (temp < min) {
893                 min           = temp;
894                 max_amp_index = j;
895             }
896         }
897 
898         max_amp_index--;
899         /* Select additional gain values */
900         for (j = 1; j < 5; j++) {
901             for (k = i; k < SUBFRAME_LEN; k += GRID_SIZE) {
902                 temp_corr[k] = 0;
903                 ccr2[k]      = ccr1[k];
904             }
905             param.amp_index = max_amp_index + j - 2;
906             amp             = ff_g723_1_fixed_cb_gain[param.amp_index];
907 
908             param.pulse_sign[0] = (ccr2[param.pulse_pos[0]] < 0) ? -amp : amp;
909             temp_corr[param.pulse_pos[0]] = 1;
910 
911             for (k = 1; k < pulse_cnt; k++) {
912                 max = INT_MIN;
913                 for (l = i; l < SUBFRAME_LEN; l += GRID_SIZE) {
914                     if (temp_corr[l])
915                         continue;
916                     temp = impulse_corr[FFABS(l - param.pulse_pos[k - 1])];
917                     temp = av_clipl_int32((int64_t) temp *
918                                           param.pulse_sign[k - 1] << 1);
919                     ccr2[l] -= temp;
920                     temp     = FFABS(ccr2[l]);
921                     if (temp > max) {
922                         max                = temp;
923                         param.pulse_pos[k] = l;
924                     }
925                 }
926 
927                 param.pulse_sign[k] = (ccr2[param.pulse_pos[k]] < 0) ?
928                                       -amp : amp;
929                 temp_corr[param.pulse_pos[k]] = 1;
930             }
931 
932             /* Create the error vector */
933             memset(temp_corr, 0, sizeof(int16_t) * SUBFRAME_LEN);
934 
935             for (k = 0; k < pulse_cnt; k++)
936                 temp_corr[param.pulse_pos[k]] = param.pulse_sign[k];
937 
938             for (k = SUBFRAME_LEN - 1; k >= 0; k--) {
939                 temp = 0;
940                 for (l = 0; l <= k; l++) {
941                     int prod = av_clipl_int32((int64_t) temp_corr[l] *
942                                               impulse_r[k - l] << 1);
943                     temp = av_clipl_int32(temp + prod);
944                 }
945                 temp_corr[k] = temp << 2 >> 16;
946             }
947 
948             /* Compute square of error */
949             err = 0;
950             for (k = 0; k < SUBFRAME_LEN; k++) {
951                 int64_t prod;
952                 prod = av_clipl_int32((int64_t) buf[k] * temp_corr[k] << 1);
953                 err  = av_clipl_int32(err - prod);
954                 prod = av_clipl_int32((int64_t) temp_corr[k] * temp_corr[k]);
955                 err  = av_clipl_int32(err + prod);
956             }
957 
958             /* Minimize */
959             if (err < optim->min_err) {
960                 optim->min_err     = err;
961                 optim->grid_index  = i;
962                 optim->amp_index   = param.amp_index;
963                 optim->dirac_train = param.dirac_train;
964 
965                 for (k = 0; k < pulse_cnt; k++) {
966                     optim->pulse_sign[k] = param.pulse_sign[k];
967                     optim->pulse_pos[k]  = param.pulse_pos[k];
968                 }
969             }
970         }
971     }
972 }
973 
974 /**
975  * Encode the pulse position and gain of the current subframe.
976  *
977  * @param optim optimized fixed CB parameters
978  * @param buf   excitation vector
979  */
pack_fcb_param(G723_1_Subframe * subfrm,FCBParam * optim,int16_t * buf,int pulse_cnt)980 static void pack_fcb_param(G723_1_Subframe *subfrm, FCBParam *optim,
981                            int16_t *buf, int pulse_cnt)
982 {
983     int i, j;
984 
985     j = PULSE_MAX - pulse_cnt;
986 
987     subfrm->pulse_sign = 0;
988     subfrm->pulse_pos  = 0;
989 
990     for (i = 0; i < SUBFRAME_LEN >> 1; i++) {
991         int val = buf[optim->grid_index + (i << 1)];
992         if (!val) {
993             subfrm->pulse_pos += ff_g723_1_combinatorial_table[j][i];
994         } else {
995             subfrm->pulse_sign <<= 1;
996             if (val < 0)
997                 subfrm->pulse_sign++;
998             j++;
999 
1000             if (j == PULSE_MAX)
1001                 break;
1002         }
1003     }
1004     subfrm->amp_index   = optim->amp_index;
1005     subfrm->grid_index  = optim->grid_index;
1006     subfrm->dirac_train = optim->dirac_train;
1007 }
1008 
1009 /**
1010  * Compute the fixed codebook excitation.
1011  *
1012  * @param buf          target vector
1013  * @param impulse_resp impulse response of the combined filter
1014  */
fcb_search(G723_1_ChannelContext * p,int16_t * impulse_resp,int16_t * buf,int index)1015 static void fcb_search(G723_1_ChannelContext *p, int16_t *impulse_resp,
1016                        int16_t *buf, int index)
1017 {
1018     FCBParam optim;
1019     int pulse_cnt = pulses[index];
1020     int i;
1021 
1022     optim.min_err = 1 << 30;
1023     get_fcb_param(&optim, impulse_resp, buf, pulse_cnt, SUBFRAME_LEN);
1024 
1025     if (p->pitch_lag[index >> 1] < SUBFRAME_LEN - 2) {
1026         get_fcb_param(&optim, impulse_resp, buf, pulse_cnt,
1027                       p->pitch_lag[index >> 1]);
1028     }
1029 
1030     /* Reconstruct the excitation */
1031     memset(buf, 0, sizeof(int16_t) * SUBFRAME_LEN);
1032     for (i = 0; i < pulse_cnt; i++)
1033         buf[optim.pulse_pos[i]] = optim.pulse_sign[i];
1034 
1035     pack_fcb_param(&p->subframe[index], &optim, buf, pulse_cnt);
1036 
1037     if (optim.dirac_train)
1038         ff_g723_1_gen_dirac_train(buf, p->pitch_lag[index >> 1]);
1039 }
1040 
1041 /**
1042  * Pack the frame parameters into output bitstream.
1043  *
1044  * @param frame output buffer
1045  * @param size  size of the buffer
1046  */
pack_bitstream(G723_1_ChannelContext * p,AVPacket * avpkt)1047 static int pack_bitstream(G723_1_ChannelContext *p, AVPacket *avpkt)
1048 {
1049     PutBitContext pb;
1050     int info_bits = 0;
1051     int i, temp;
1052 
1053     init_put_bits(&pb, avpkt->data, avpkt->size);
1054 
1055     put_bits(&pb, 2, info_bits);
1056 
1057     put_bits(&pb, 8, p->lsp_index[2]);
1058     put_bits(&pb, 8, p->lsp_index[1]);
1059     put_bits(&pb, 8, p->lsp_index[0]);
1060 
1061     put_bits(&pb, 7, p->pitch_lag[0] - PITCH_MIN);
1062     put_bits(&pb, 2, p->subframe[1].ad_cb_lag);
1063     put_bits(&pb, 7, p->pitch_lag[1] - PITCH_MIN);
1064     put_bits(&pb, 2, p->subframe[3].ad_cb_lag);
1065 
1066     /* Write 12 bit combined gain */
1067     for (i = 0; i < SUBFRAMES; i++) {
1068         temp = p->subframe[i].ad_cb_gain * GAIN_LEVELS +
1069                p->subframe[i].amp_index;
1070         if (p->cur_rate == RATE_6300)
1071             temp += p->subframe[i].dirac_train << 11;
1072         put_bits(&pb, 12, temp);
1073     }
1074 
1075     put_bits(&pb, 1, p->subframe[0].grid_index);
1076     put_bits(&pb, 1, p->subframe[1].grid_index);
1077     put_bits(&pb, 1, p->subframe[2].grid_index);
1078     put_bits(&pb, 1, p->subframe[3].grid_index);
1079 
1080     if (p->cur_rate == RATE_6300) {
1081         put_bits(&pb, 1, 0); /* reserved bit */
1082 
1083         /* Write 13 bit combined position index */
1084         temp = (p->subframe[0].pulse_pos >> 16) * 810 +
1085                (p->subframe[1].pulse_pos >> 14) *  90 +
1086                (p->subframe[2].pulse_pos >> 16) *   9 +
1087                (p->subframe[3].pulse_pos >> 14);
1088         put_bits(&pb, 13, temp);
1089 
1090         put_bits(&pb, 16, p->subframe[0].pulse_pos & 0xffff);
1091         put_bits(&pb, 14, p->subframe[1].pulse_pos & 0x3fff);
1092         put_bits(&pb, 16, p->subframe[2].pulse_pos & 0xffff);
1093         put_bits(&pb, 14, p->subframe[3].pulse_pos & 0x3fff);
1094 
1095         put_bits(&pb, 6, p->subframe[0].pulse_sign);
1096         put_bits(&pb, 5, p->subframe[1].pulse_sign);
1097         put_bits(&pb, 6, p->subframe[2].pulse_sign);
1098         put_bits(&pb, 5, p->subframe[3].pulse_sign);
1099     }
1100 
1101     flush_put_bits(&pb);
1102     return frame_size[info_bits];
1103 }
1104 
g723_1_encode_frame(AVCodecContext * avctx,AVPacket * avpkt,const AVFrame * frame,int * got_packet_ptr)1105 static int g723_1_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
1106                                const AVFrame *frame, int *got_packet_ptr)
1107 {
1108     G723_1_Context *s = avctx->priv_data;
1109     G723_1_ChannelContext *p = &s->ch[0];
1110     int16_t unq_lpc[LPC_ORDER * SUBFRAMES];
1111     int16_t qnt_lpc[LPC_ORDER * SUBFRAMES];
1112     int16_t cur_lsp[LPC_ORDER];
1113     int16_t weighted_lpc[LPC_ORDER * SUBFRAMES << 1];
1114     int16_t vector[FRAME_LEN + PITCH_MAX];
1115     int offset, ret, i, j;
1116     int16_t *in, *start;
1117     HFParam hf[4];
1118 
1119     /* duplicate input */
1120     start = in = av_malloc(frame->nb_samples * sizeof(int16_t));
1121     if (!in)
1122         return AVERROR(ENOMEM);
1123     memcpy(in, frame->data[0], frame->nb_samples * sizeof(int16_t));
1124 
1125     highpass_filter(in, &p->hpf_fir_mem, &p->hpf_iir_mem);
1126 
1127     memcpy(vector, p->prev_data, HALF_FRAME_LEN * sizeof(int16_t));
1128     memcpy(vector + HALF_FRAME_LEN, in, FRAME_LEN * sizeof(int16_t));
1129 
1130     comp_lpc_coeff(vector, unq_lpc);
1131     lpc2lsp(&unq_lpc[LPC_ORDER * 3], p->prev_lsp, cur_lsp);
1132     lsp_quantize(p->lsp_index, cur_lsp, p->prev_lsp);
1133 
1134     /* Update memory */
1135     memcpy(vector + LPC_ORDER, p->prev_data + SUBFRAME_LEN,
1136            sizeof(int16_t) * SUBFRAME_LEN);
1137     memcpy(vector + LPC_ORDER + SUBFRAME_LEN, in,
1138            sizeof(int16_t) * (HALF_FRAME_LEN + SUBFRAME_LEN));
1139     memcpy(p->prev_data, in + HALF_FRAME_LEN,
1140            sizeof(int16_t) * HALF_FRAME_LEN);
1141     memcpy(in, vector + LPC_ORDER, sizeof(int16_t) * FRAME_LEN);
1142 
1143     perceptual_filter(p, weighted_lpc, unq_lpc, vector);
1144 
1145     memcpy(in, vector + LPC_ORDER, sizeof(int16_t) * FRAME_LEN);
1146     memcpy(vector, p->prev_weight_sig, sizeof(int16_t) * PITCH_MAX);
1147     memcpy(vector + PITCH_MAX, in, sizeof(int16_t) * FRAME_LEN);
1148 
1149     ff_g723_1_scale_vector(vector, vector, FRAME_LEN + PITCH_MAX);
1150 
1151     p->pitch_lag[0] = estimate_pitch(vector, PITCH_MAX);
1152     p->pitch_lag[1] = estimate_pitch(vector, PITCH_MAX + HALF_FRAME_LEN);
1153 
1154     for (i = PITCH_MAX, j = 0; j < SUBFRAMES; i += SUBFRAME_LEN, j++)
1155         comp_harmonic_coeff(vector + i, p->pitch_lag[j >> 1], hf + j);
1156 
1157     memcpy(vector, p->prev_weight_sig, sizeof(int16_t) * PITCH_MAX);
1158     memcpy(vector + PITCH_MAX, in, sizeof(int16_t) * FRAME_LEN);
1159     memcpy(p->prev_weight_sig, vector + FRAME_LEN, sizeof(int16_t) * PITCH_MAX);
1160 
1161     for (i = 0, j = 0; j < SUBFRAMES; i += SUBFRAME_LEN, j++)
1162         harmonic_filter(hf + j, vector + PITCH_MAX + i, in + i);
1163 
1164     ff_g723_1_inverse_quant(cur_lsp, p->prev_lsp, p->lsp_index, 0);
1165     ff_g723_1_lsp_interpolate(qnt_lpc, cur_lsp, p->prev_lsp);
1166 
1167     memcpy(p->prev_lsp, cur_lsp, sizeof(int16_t) * LPC_ORDER);
1168 
1169     offset = 0;
1170     for (i = 0; i < SUBFRAMES; i++) {
1171         int16_t impulse_resp[SUBFRAME_LEN];
1172         int16_t residual[SUBFRAME_LEN + PITCH_ORDER - 1];
1173         int16_t flt_in[SUBFRAME_LEN];
1174         int16_t zero[LPC_ORDER], fir[LPC_ORDER], iir[LPC_ORDER];
1175 
1176         /**
1177          * Compute the combined impulse response of the synthesis filter,
1178          * formant perceptual weighting filter and harmonic noise shaping filter
1179          */
1180         memset(zero, 0, sizeof(int16_t) * LPC_ORDER);
1181         memset(vector, 0, sizeof(int16_t) * PITCH_MAX);
1182         memset(flt_in, 0, sizeof(int16_t) * SUBFRAME_LEN);
1183 
1184         flt_in[0] = 1 << 13; /* Unit impulse */
1185         synth_percept_filter(qnt_lpc + offset, weighted_lpc + (offset << 1),
1186                              zero, zero, flt_in, vector + PITCH_MAX, 1);
1187         harmonic_filter(hf + i, vector + PITCH_MAX, impulse_resp);
1188 
1189         /* Compute the combined zero input response */
1190         flt_in[0] = 0;
1191         memcpy(fir, p->perf_fir_mem, sizeof(int16_t) * LPC_ORDER);
1192         memcpy(iir, p->perf_iir_mem, sizeof(int16_t) * LPC_ORDER);
1193 
1194         synth_percept_filter(qnt_lpc + offset, weighted_lpc + (offset << 1),
1195                              fir, iir, flt_in, vector + PITCH_MAX, 0);
1196         memcpy(vector, p->harmonic_mem, sizeof(int16_t) * PITCH_MAX);
1197         harmonic_noise_sub(hf + i, vector + PITCH_MAX, in);
1198 
1199         acb_search(p, residual, impulse_resp, in, i);
1200         ff_g723_1_gen_acb_excitation(residual, p->prev_excitation,
1201                                      p->pitch_lag[i >> 1], &p->subframe[i],
1202                                      p->cur_rate);
1203         sub_acb_contrib(residual, impulse_resp, in);
1204 
1205         fcb_search(p, impulse_resp, in, i);
1206 
1207         /* Reconstruct the excitation */
1208         ff_g723_1_gen_acb_excitation(impulse_resp, p->prev_excitation,
1209                                      p->pitch_lag[i >> 1], &p->subframe[i],
1210                                      RATE_6300);
1211 
1212         memmove(p->prev_excitation, p->prev_excitation + SUBFRAME_LEN,
1213                 sizeof(int16_t) * (PITCH_MAX - SUBFRAME_LEN));
1214         for (j = 0; j < SUBFRAME_LEN; j++)
1215             in[j] = av_clip_int16((in[j] << 1) + impulse_resp[j]);
1216         memcpy(p->prev_excitation + PITCH_MAX - SUBFRAME_LEN, in,
1217                sizeof(int16_t) * SUBFRAME_LEN);
1218 
1219         /* Update filter memories */
1220         synth_percept_filter(qnt_lpc + offset, weighted_lpc + (offset << 1),
1221                              p->perf_fir_mem, p->perf_iir_mem,
1222                              in, vector + PITCH_MAX, 0);
1223         memmove(p->harmonic_mem, p->harmonic_mem + SUBFRAME_LEN,
1224                 sizeof(int16_t) * (PITCH_MAX - SUBFRAME_LEN));
1225         memcpy(p->harmonic_mem + PITCH_MAX - SUBFRAME_LEN, vector + PITCH_MAX,
1226                sizeof(int16_t) * SUBFRAME_LEN);
1227 
1228         in     += SUBFRAME_LEN;
1229         offset += LPC_ORDER;
1230     }
1231 
1232     av_free(start);
1233 
1234     if ((ret = ff_alloc_packet2(avctx, avpkt, 24, 0)) < 0)
1235         return ret;
1236 
1237     *got_packet_ptr = 1;
1238     avpkt->size = pack_bitstream(p, avpkt);
1239     return 0;
1240 }
1241 
1242 static const AVCodecDefault defaults[] = {
1243     { "b", "6300" },
1244     { NULL },
1245 };
1246 
1247 AVCodec ff_g723_1_encoder = {
1248     .name           = "g723_1",
1249     .long_name      = NULL_IF_CONFIG_SMALL("G.723.1"),
1250     .type           = AVMEDIA_TYPE_AUDIO,
1251     .id             = AV_CODEC_ID_G723_1,
1252     .priv_data_size = sizeof(G723_1_Context),
1253     .init           = g723_1_encode_init,
1254     .encode2        = g723_1_encode_frame,
1255     .defaults       = defaults,
1256     .sample_fmts    = (const enum AVSampleFormat[]) {
1257         AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE
1258     },
1259 };
1260