xref: /third_party/ffmpeg/libavcodec/g723_1enc.c (revision cabdff1a)
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 */
47static 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 */
71static 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 */
78static 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 */
85static 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
92static 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 */
125static 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 */
141static 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 */
183static 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 */
227static 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
243static 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 */
363static 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 */
411static 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 */
434static 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 */
466static 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)) {
522update:
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 */
539static 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 */
612static 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
622static 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 */
641static 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 */
683static 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 */
801static 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 */
821static 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 */
976static 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 */
1011static 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 */
1043static 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
1099static 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
1236static const FFCodecDefault defaults[] = {
1237    { "b", "6300" },
1238    { NULL },
1239};
1240
1241const 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