Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / evrcdec.c
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DM
1/*
2 * Enhanced Variable Rate Codec, Service Option 3 decoder
3 * Copyright (c) 2013 Paul B Mahol
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 * Enhanced Variable Rate Codec, Service Option 3 decoder
25 * @author Paul B Mahol
26 */
27
28#include "libavutil/mathematics.h"
29#include "avcodec.h"
30#include "internal.h"
31#include "get_bits.h"
32#include "evrcdata.h"
33#include "acelp_vectors.h"
34#include "lsp.h"
35
36#define MIN_LSP_SEP (0.05 / (2.0 * M_PI))
37#define MIN_DELAY 20
38#define MAX_DELAY 120
39#define NB_SUBFRAMES 3
40#define SUBFRAME_SIZE 54
41#define FILTER_ORDER 10
42#define ACB_SIZE 128
43
44typedef enum {
45 RATE_ERRS = -1,
46 SILENCE,
47 RATE_QUANT,
48 RATE_QUARTER,
49 RATE_HALF,
50 RATE_FULL,
51} evrc_packet_rate;
52
53/**
54 * EVRC-A unpacked data frame
55 */
56typedef struct EVRCAFrame {
57 uint8_t lpc_flag; ///< spectral change indicator
58 uint16_t lsp[4]; ///< index into LSP codebook
59 uint8_t pitch_delay; ///< pitch delay for entire frame
60 uint8_t delay_diff; ///< delay difference for entire frame
61 uint8_t acb_gain[3]; ///< adaptive codebook gain
62 uint16_t fcb_shape[3][4]; ///< fixed codebook shape
63 uint8_t fcb_gain[3]; ///< fixed codebook gain index
64 uint8_t energy_gain; ///< frame energy gain index
65 uint8_t tty; ///< tty baud rate bit
66} EVRCAFrame;
67
68typedef struct EVRCContext {
69 GetBitContext gb;
70 evrc_packet_rate bitrate;
71 evrc_packet_rate last_valid_bitrate;
72 EVRCAFrame frame;
73
74 float lspf[FILTER_ORDER];
75 float prev_lspf[FILTER_ORDER];
76 float synthesis[FILTER_ORDER];
77 float postfilter_fir[FILTER_ORDER];
78 float postfilter_iir[FILTER_ORDER];
79 float postfilter_residual[ACB_SIZE + SUBFRAME_SIZE];
80 float pitch_delay;
81 float prev_pitch_delay;
82 float avg_acb_gain; ///< average adaptive codebook gain
83 float avg_fcb_gain; ///< average fixed codebook gain
84 float pitch[ACB_SIZE + FILTER_ORDER + SUBFRAME_SIZE];
85 float pitch_back[ACB_SIZE];
86 float interpolation_coeffs[136];
87 float energy_vector[NB_SUBFRAMES];
88 float fade_scale;
89 float last;
90
91 uint8_t prev_energy_gain;
92 uint8_t prev_error_flag;
93 uint8_t warned_buf_mismatch_bitrate;
94} EVRCContext;
95
96/**
97 * Frame unpacking for RATE_FULL, RATE_HALF and RATE_QUANT
98 *
99 * @param e the context
100 *
101 * TIA/IS-127 Table 4.21-1
102 */
103static void unpack_frame(EVRCContext *e)
104{
105 EVRCAFrame *frame = &e->frame;
106 GetBitContext *gb = &e->gb;
107
108 switch (e->bitrate) {
109 case RATE_FULL:
110 frame->lpc_flag = get_bits1(gb);
111 frame->lsp[0] = get_bits(gb, 6);
112 frame->lsp[1] = get_bits(gb, 6);
113 frame->lsp[2] = get_bits(gb, 9);
114 frame->lsp[3] = get_bits(gb, 7);
115 frame->pitch_delay = get_bits(gb, 7);
116 frame->delay_diff = get_bits(gb, 5);
117 frame->acb_gain[0] = get_bits(gb, 3);
118 frame->fcb_shape[0][0] = get_bits(gb, 8);
119 frame->fcb_shape[0][1] = get_bits(gb, 8);
120 frame->fcb_shape[0][2] = get_bits(gb, 8);
121 frame->fcb_shape[0][3] = get_bits(gb, 11);
122 frame->fcb_gain[0] = get_bits(gb, 5);
123 frame->acb_gain[1] = get_bits(gb, 3);
124 frame->fcb_shape[1][0] = get_bits(gb, 8);
125 frame->fcb_shape[1][1] = get_bits(gb, 8);
126 frame->fcb_shape[1][2] = get_bits(gb, 8);
127 frame->fcb_shape[1][3] = get_bits(gb, 11);
128 frame->fcb_gain [1] = get_bits(gb, 5);
129 frame->acb_gain [2] = get_bits(gb, 3);
130 frame->fcb_shape[2][0] = get_bits(gb, 8);
131 frame->fcb_shape[2][1] = get_bits(gb, 8);
132 frame->fcb_shape[2][2] = get_bits(gb, 8);
133 frame->fcb_shape[2][3] = get_bits(gb, 11);
134 frame->fcb_gain [2] = get_bits(gb, 5);
135 frame->tty = get_bits1(gb);
136 break;
137 case RATE_HALF:
138 frame->lsp [0] = get_bits(gb, 7);
139 frame->lsp [1] = get_bits(gb, 7);
140 frame->lsp [2] = get_bits(gb, 8);
141 frame->pitch_delay = get_bits(gb, 7);
142 frame->acb_gain [0] = get_bits(gb, 3);
143 frame->fcb_shape[0][0] = get_bits(gb, 10);
144 frame->fcb_gain [0] = get_bits(gb, 4);
145 frame->acb_gain [1] = get_bits(gb, 3);
146 frame->fcb_shape[1][0] = get_bits(gb, 10);
147 frame->fcb_gain [1] = get_bits(gb, 4);
148 frame->acb_gain [2] = get_bits(gb, 3);
149 frame->fcb_shape[2][0] = get_bits(gb, 10);
150 frame->fcb_gain [2] = get_bits(gb, 4);
151 break;
152 case RATE_QUANT:
153 frame->lsp [0] = get_bits(gb, 4);
154 frame->lsp [1] = get_bits(gb, 4);
155 frame->energy_gain = get_bits(gb, 8);
156 break;
157 }
158}
159
160static evrc_packet_rate buf_size2bitrate(const int buf_size)
161{
162 switch (buf_size) {
163 case 23: return RATE_FULL;
164 case 11: return RATE_HALF;
165 case 6: return RATE_QUARTER;
166 case 3: return RATE_QUANT;
167 case 1: return SILENCE;
168 }
169
170 return RATE_ERRS;
171}
172
173/**
174 * Determine the bitrate from the frame size and/or the first byte of the frame.
175 *
176 * @param avctx the AV codec context
177 * @param buf_size length of the buffer
178 * @param buf the bufffer
179 *
180 * @return the bitrate on success,
181 * RATE_ERRS if the bitrate cannot be satisfactorily determined
182 */
183static evrc_packet_rate determine_bitrate(AVCodecContext *avctx,
184 int *buf_size,
185 const uint8_t **buf)
186{
187 evrc_packet_rate bitrate;
188
189 if ((bitrate = buf_size2bitrate(*buf_size)) >= 0) {
190 if (bitrate > **buf) {
191 EVRCContext *e = avctx->priv_data;
192 if (!e->warned_buf_mismatch_bitrate) {
193 av_log(avctx, AV_LOG_WARNING,
194 "Claimed bitrate and buffer size mismatch.\n");
195 e->warned_buf_mismatch_bitrate = 1;
196 }
197 bitrate = **buf;
198 } else if (bitrate < **buf) {
199 av_log(avctx, AV_LOG_ERROR,
200 "Buffer is too small for the claimed bitrate.\n");
201 return RATE_ERRS;
202 }
203 (*buf)++;
204 *buf_size -= 1;
205 } else if ((bitrate = buf_size2bitrate(*buf_size + 1)) >= 0) {
206 av_log(avctx, AV_LOG_DEBUG,
207 "Bitrate byte is missing, guessing the bitrate from packet size.\n");
208 } else
209 return RATE_ERRS;
210
211 return bitrate;
212}
213
214static void warn_insufficient_frame_quality(AVCodecContext *avctx,
215 const char *message)
216{
217 av_log(avctx, AV_LOG_WARNING, "Frame #%d, %s\n",
218 avctx->frame_number, message);
219}
220
221/**
222 * Initialize the speech codec according to the specification.
223 *
224 * TIA/IS-127 5.2
225 */
226static av_cold int evrc_decode_init(AVCodecContext *avctx)
227{
228 EVRCContext *e = avctx->priv_data;
229 int i, n, idx = 0;
230 float denom = 2.0 / (2.0 * 8.0 + 1.0);
231
232 avctx->channels = 1;
233 avctx->channel_layout = AV_CH_LAYOUT_MONO;
234 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
235
236 for (i = 0; i < FILTER_ORDER; i++) {
237 e->prev_lspf[i] = (i + 1) * 0.048;
238 e->synthesis[i] = 0.0;
239 }
240
241 for (i = 0; i < ACB_SIZE; i++)
242 e->pitch[i] = e->pitch_back[i] = 0.0;
243
244 e->last_valid_bitrate = RATE_QUANT;
245 e->prev_pitch_delay = 40.0;
246 e->fade_scale = 1.0;
247 e->prev_error_flag = 0;
248 e->avg_acb_gain = e->avg_fcb_gain = 0.0;
249
250 for (i = 0; i < 8; i++) {
251 float tt = ((float)i - 8.0 / 2.0) / 8.0;
252
253 for (n = -8; n <= 8; n++, idx++) {
254 float arg1 = M_PI * 0.9 * (tt - n);
255 float arg2 = M_PI * (tt - n);
256
257 e->interpolation_coeffs[idx] = 0.9;
258 if (arg1)
259 e->interpolation_coeffs[idx] *= (0.54 + 0.46 * cos(arg2 * denom)) *
260 sin(arg1) / arg1;
261 }
262 }
263
264 return 0;
265}
266
267/**
268 * Decode the 10 vector quantized line spectral pair frequencies from the LSP
269 * transmission codes of any bitrate and check for badly received packets.
270 *
271 * @param e the context
272 *
273 * @return 0 on success, -1 if the packet is badly received
274 *
275 * TIA/IS-127 5.2.1, 5.7.1
276 */
277static int decode_lspf(EVRCContext *e)
278{
279 const float * const *codebooks = evrc_lspq_codebooks[e->bitrate];
280 int i, j, k = 0;
281
282 for (i = 0; i < evrc_lspq_nb_codebooks[e->bitrate]; i++) {
283 int row_size = evrc_lspq_codebooks_row_sizes[e->bitrate][i];
284 const float *codebook = codebooks[i];
285
286 for (j = 0; j < row_size; j++)
287 e->lspf[k++] = codebook[e->frame.lsp[i] * row_size + j];
288 }
289
290 // check for monotonic LSPs
291 for (i = 1; i < FILTER_ORDER; i++)
292 if (e->lspf[i] <= e->lspf[i - 1])
293 return -1;
294
295 // check for minimum separation of LSPs at the splits
296 for (i = 0, k = 0; i < evrc_lspq_nb_codebooks[e->bitrate] - 1; i++) {
297 k += evrc_lspq_codebooks_row_sizes[e->bitrate][i];
298 if (e->lspf[k] - e->lspf[k - 1] <= MIN_LSP_SEP)
299 return -1;
300 }
301
302 return 0;
303}
304
305/*
306 * Interpolation of LSP parameters.
307 *
308 * TIA/IS-127 5.2.3.1, 5.7.3.2
309 */
310static void interpolate_lsp(float *ilsp, const float *lsp,
311 const float *prev, int index)
312{
313 static const float lsp_interpolation_factors[] = { 0.1667, 0.5, 0.8333 };
314 ff_weighted_vector_sumf(ilsp, prev, lsp,
315 1.0 - lsp_interpolation_factors[index],
316 lsp_interpolation_factors[index], FILTER_ORDER);
317}
318
319/*
320 * Reconstruction of the delay contour.
321 *
322 * TIA/IS-127 5.2.2.3.2
323 */
324static void interpolate_delay(float *dst, float current, float prev, int index)
325{
326 static const float d_interpolation_factors[] = { 0, 0.3313, 0.6625, 1, 1 };
327 dst[0] = (1.0 - d_interpolation_factors[index ]) * prev
328 + d_interpolation_factors[index ] * current;
329 dst[1] = (1.0 - d_interpolation_factors[index + 1]) * prev
330 + d_interpolation_factors[index + 1] * current;
331 dst[2] = (1.0 - d_interpolation_factors[index + 2]) * prev
332 + d_interpolation_factors[index + 2] * current;
333}
334
335/*
336 * Convert the quantized, interpolated line spectral frequencies,
337 * to prediction coefficients.
338 *
339 * TIA/IS-127 5.2.3.2, 4.7.2.2
340 */
341static void decode_predictor_coeffs(const float *ilspf, float *ilpc)
342{
343 double lsp[FILTER_ORDER];
344 float a[FILTER_ORDER / 2 + 1], b[FILTER_ORDER / 2 + 1];
345 float a1[FILTER_ORDER / 2] = { 0 };
346 float a2[FILTER_ORDER / 2] = { 0 };
347 float b1[FILTER_ORDER / 2] = { 0 };
348 float b2[FILTER_ORDER / 2] = { 0 };
349 int i, k;
350
351 ff_acelp_lsf2lspd(lsp, ilspf, FILTER_ORDER);
352
353 for (k = 0; k <= FILTER_ORDER; k++) {
354 a[0] = k < 2 ? 0.25 : 0;
355 b[0] = k < 2 ? k < 1 ? 0.25 : -0.25 : 0;
356
357 for (i = 0; i < FILTER_ORDER / 2; i++) {
358 a[i + 1] = a[i] - 2 * lsp[i * 2 ] * a1[i] + a2[i];
359 b[i + 1] = b[i] - 2 * lsp[i * 2 + 1] * b1[i] + b2[i];
360 a2[i] = a1[i];
361 a1[i] = a[i];
362 b2[i] = b1[i];
363 b1[i] = b[i];
364 }
365
366 if (k)
367 ilpc[k - 1] = 2.0 * (a[FILTER_ORDER / 2] + b[FILTER_ORDER / 2]);
368 }
369}
370
371static void bl_intrp(EVRCContext *e, float *ex, float delay)
372{
373 float *f;
374 int offset, i, coef_idx;
375 int16_t t;
376
377 offset = lrintf(delay);
378
379 t = (offset - delay + 0.5) * 8.0 + 0.5;
380 if (t == 8) {
381 t = 0;
382 offset--;
383 }
384
385 f = ex - offset - 8;
386
387 coef_idx = t * (2 * 8 + 1);
388
389 ex[0] = 0.0;
390 for (i = 0; i < 2 * 8 + 1; i++)
391 ex[0] += e->interpolation_coeffs[coef_idx + i] * f[i];
392}
393
394/*
395 * Adaptive codebook excitation.
396 *
397 * TIA/IS-127 5.2.2.3.3, 4.12.5.2
398 */
399static void acb_excitation(EVRCContext *e, float *excitation, float gain,
400 const float delay[3], int length)
401{
402 float denom, locdelay, dpr, invl;
403 int i;
404
405 invl = 1.0 / ((float) length);
406 dpr = length;
407
408 /* first at-most extra samples */
409 denom = (delay[1] - delay[0]) * invl;
410 for (i = 0; i < dpr; i++) {
411 locdelay = delay[0] + i * denom;
412 bl_intrp(e, excitation + i, locdelay);
413 }
414
415 denom = (delay[2] - delay[1]) * invl;
416 /* interpolation */
417 for (i = dpr; i < dpr + 10; i++) {
418 locdelay = delay[1] + (i - dpr) * denom;
419 bl_intrp(e, excitation + i, locdelay);
420 }
421
422 for (i = 0; i < length; i++)
423 excitation[i] *= gain;
424}
425
426static void decode_8_pulses_35bits(const uint16_t *fixed_index, float *cod)
427{
428 int i, pos1, pos2, offset;
429
430 offset = (fixed_index[3] >> 9) & 3;
431
432 for (i = 0; i < 3; i++) {
433 pos1 = ((fixed_index[i] & 0x7f) / 11) * 5 + ((i + offset) % 5);
434 pos2 = ((fixed_index[i] & 0x7f) % 11) * 5 + ((i + offset) % 5);
435
436 cod[pos1] = (fixed_index[i] & 0x80) ? -1.0 : 1.0;
437
438 if (pos2 < pos1)
439 cod[pos2] = -cod[pos1];
440 else
441 cod[pos2] += cod[pos1];
442 }
443
444 pos1 = ((fixed_index[3] & 0x7f) / 11) * 5 + ((3 + offset) % 5);
445 pos2 = ((fixed_index[3] & 0x7f) % 11) * 5 + ((4 + offset) % 5);
446
447 cod[pos1] = (fixed_index[3] & 0x100) ? -1.0 : 1.0;
448 cod[pos2] = (fixed_index[3] & 0x80 ) ? -1.0 : 1.0;
449}
450
451static void decode_3_pulses_10bits(uint16_t fixed_index, float *cod)
452{
453 float sign;
454 int pos;
455
456 sign = (fixed_index & 0x200) ? -1.0 : 1.0;
457
458 pos = ((fixed_index & 0x7) * 7) + 4;
459 cod[pos] += sign;
460 pos = (((fixed_index >> 3) & 0x7) * 7) + 2;
461 cod[pos] -= sign;
462 pos = (((fixed_index >> 6) & 0x7) * 7);
463 cod[pos] += sign;
464}
465
466/*
467 * Reconstruction of ACELP fixed codebook excitation for full and half rate.
468 *
469 * TIA/IS-127 5.2.3.7
470 */
471static void fcb_excitation(EVRCContext *e, const uint16_t *codebook,
472 float *excitation, float pitch_gain,
473 int pitch_lag, int subframe_size)
474{
475 int i;
476
477 if (e->bitrate == RATE_FULL)
478 decode_8_pulses_35bits(codebook, excitation);
479 else
480 decode_3_pulses_10bits(*codebook, excitation);
481
482 pitch_gain = av_clipf(pitch_gain, 0.2, 0.9);
483
484 for (i = pitch_lag; i < subframe_size; i++)
485 excitation[i] += pitch_gain * excitation[i - pitch_lag];
486}
487
488/**
489 * Synthesis of the decoder output signal.
490 *
491 * param[in] in input signal
492 * param[in] filter_coeffs LPC coefficients
493 * param[in/out] memory synthesis filter memory
494 * param buffer_length amount of data to process
495 * param[out] samples output samples
496 *
497 * TIA/IS-127 5.2.3.15, 5.7.3.4
498 */
499static void synthesis_filter(const float *in, const float *filter_coeffs,
500 float *memory, int buffer_length, float *samples)
501{
502 int i, j;
503
504 for (i = 0; i < buffer_length; i++) {
505 samples[i] = in[i];
506 for (j = FILTER_ORDER - 1; j > 0; j--) {
507 samples[i] -= filter_coeffs[j] * memory[j];
508 memory[j] = memory[j - 1];
509 }
510 samples[i] -= filter_coeffs[0] * memory[0];
511 memory[0] = samples[i];
512 }
513}
514
515static void bandwidth_expansion(float *coeff, const float *inbuf, float gamma)
516{
517 double fac = gamma;
518 int i;
519
520 for (i = 0; i < FILTER_ORDER; i++) {
521 coeff[i] = inbuf[i] * fac;
522 fac *= gamma;
523 }
524}
525
526static void residual_filter(float *output, const float *input,
527 const float *coef, float *memory, int length)
528{
529 float sum;
530 int i, j;
531
532 for (i = 0; i < length; i++) {
533 sum = input[i];
534
535 for (j = FILTER_ORDER - 1; j > 0; j--) {
536 sum += coef[j] * memory[j];
537 memory[j] = memory[j - 1];
538 }
539 sum += coef[0] * memory[0];
540 memory[0] = input[i];
541 output[i] = sum;
542 }
543}
544
545/*
546 * TIA/IS-127 Table 5.9.1-1.
547 */
548static const struct PfCoeff {
549 float tilt;
550 float ltgain;
551 float p1;
552 float p2;
553} postfilter_coeffs[5] = {
554 { 0.0 , 0.0 , 0.0 , 0.0 },
555 { 0.0 , 0.0 , 0.57, 0.57 },
556 { 0.0 , 0.0 , 0.0 , 0.0 },
557 { 0.35, 0.50, 0.50, 0.75 },
558 { 0.20, 0.50, 0.57, 0.75 },
559};
560
561/*
562 * Adaptive postfilter.
563 *
564 * TIA/IS-127 5.9
565 */
566static void postfilter(EVRCContext *e, float *in, const float *coeff,
567 float *out, int idx, const struct PfCoeff *pfc,
568 int length)
569{
570 float wcoef1[FILTER_ORDER], wcoef2[FILTER_ORDER],
571 scratch[SUBFRAME_SIZE], temp[SUBFRAME_SIZE],
572 mem[SUBFRAME_SIZE];
573 float sum1 = 0.0, sum2 = 0.0, gamma, gain;
574 float tilt = pfc->tilt;
575 int i, n, best;
576
577 bandwidth_expansion(wcoef1, coeff, pfc->p1);
578 bandwidth_expansion(wcoef2, coeff, pfc->p2);
579
580 /* Tilt compensation filter, TIA/IS-127 5.9.1 */
581 for (i = 0; i < length - 1; i++)
582 sum2 += in[i] * in[i + 1];
583 if (sum2 < 0.0)
584 tilt = 0.0;
585
586 for (i = 0; i < length; i++) {
587 scratch[i] = in[i] - tilt * e->last;
588 e->last = in[i];
589 }
590
591 /* Short term residual filter, TIA/IS-127 5.9.2 */
592 residual_filter(&e->postfilter_residual[ACB_SIZE], scratch, wcoef1, e->postfilter_fir, length);
593
594 /* Long term postfilter */
595 best = idx;
596 for (i = FFMIN(MIN_DELAY, idx - 3); i <= FFMAX(MAX_DELAY, idx + 3); i++) {
597 for (n = ACB_SIZE, sum2 = 0; n < ACB_SIZE + length; n++)
598 sum2 += e->postfilter_residual[n] * e->postfilter_residual[n - i];
599 if (sum2 > sum1) {
600 sum1 = sum2;
601 best = i;
602 }
603 }
604
605 for (i = ACB_SIZE, sum1 = 0; i < ACB_SIZE + length; i++)
606 sum1 += e->postfilter_residual[i - best] * e->postfilter_residual[i - best];
607 for (i = ACB_SIZE, sum2 = 0; i < ACB_SIZE + length; i++)
608 sum2 += e->postfilter_residual[i] * e->postfilter_residual[i - best];
609
610 if (sum2 * sum1 == 0 || e->bitrate == RATE_QUANT) {
611 memcpy(temp, e->postfilter_residual + ACB_SIZE, length * sizeof(float));
612 } else {
613 gamma = sum2 / sum1;
614 if (gamma < 0.5)
615 memcpy(temp, e->postfilter_residual + ACB_SIZE, length * sizeof(float));
616 else {
617 gamma = FFMIN(gamma, 1.0);
618
619 for (i = 0; i < length; i++) {
620 temp[i] = e->postfilter_residual[ACB_SIZE + i] + gamma *
621 pfc->ltgain * e->postfilter_residual[ACB_SIZE + i - best];
622 }
623 }
624 }
625
626 memcpy(scratch, temp, length * sizeof(float));
627 memcpy(mem, e->postfilter_iir, FILTER_ORDER * sizeof(float));
628 synthesis_filter(scratch, wcoef2, mem, length, scratch);
629
630 /* Gain computation, TIA/IS-127 5.9.4-2 */
631 for (i = 0, sum1 = 0, sum2 = 0; i < length; i++) {
632 sum1 += in[i] * in[i];
633 sum2 += scratch[i] * scratch[i];
634 }
635 gain = sum2 ? sqrt(sum1 / sum2) : 1.0;
636
637 for (i = 0; i < length; i++)
638 temp[i] *= gain;
639
640 /* Short term postfilter */
641 synthesis_filter(temp, wcoef2, e->postfilter_iir, length, out);
642
643 memmove(e->postfilter_residual,
644 e->postfilter_residual + length, ACB_SIZE * sizeof(float));
645}
646
647static void frame_erasure(EVRCContext *e, float *samples)
648{
649 float ilspf[FILTER_ORDER], ilpc[FILTER_ORDER], idelay[NB_SUBFRAMES],
650 tmp[SUBFRAME_SIZE + 6], f;
651 int i, j;
652
653 for (i = 0; i < FILTER_ORDER; i++) {
654 if (e->bitrate != RATE_QUANT)
655 e->lspf[i] = e->prev_lspf[i] * 0.875 + 0.125 * (i + 1) * 0.048;
656 else
657 e->lspf[i] = e->prev_lspf[i];
658 }
659
660 if (e->prev_error_flag)
661 e->avg_acb_gain *= 0.75;
662 if (e->bitrate == RATE_FULL)
663 memcpy(e->pitch_back, e->pitch, ACB_SIZE * sizeof(float));
664 if (e->last_valid_bitrate == RATE_QUANT)
665 e->bitrate = RATE_QUANT;
666 else
667 e->bitrate = RATE_FULL;
668
669 if (e->bitrate == RATE_FULL || e->bitrate == RATE_HALF) {
670 e->pitch_delay = e->prev_pitch_delay;
671 } else {
672 float sum = 0;
673
674 idelay[0] = idelay[1] = idelay[2] = MIN_DELAY;
675
676 for (i = 0; i < NB_SUBFRAMES; i++)
677 sum += evrc_energy_quant[e->prev_energy_gain][i];
678 sum /= (float) NB_SUBFRAMES;
679 sum = pow(10, sum);
680 for (i = 0; i < NB_SUBFRAMES; i++)
681 e->energy_vector[i] = sum;
682 }
683
684 if (fabs(e->pitch_delay - e->prev_pitch_delay) > 15)
685 e->prev_pitch_delay = e->pitch_delay;
686
687 for (i = 0; i < NB_SUBFRAMES; i++) {
688 int subframe_size = subframe_sizes[i];
689 int pitch_lag;
690
691 interpolate_lsp(ilspf, e->lspf, e->prev_lspf, i);
692
693 if (e->bitrate != RATE_QUANT) {
694 if (e->avg_acb_gain < 0.3) {
695 idelay[0] = estimation_delay[i];
696 idelay[1] = estimation_delay[i + 1];
697 idelay[2] = estimation_delay[i + 2];
698 } else {
699 interpolate_delay(idelay, e->pitch_delay, e->prev_pitch_delay, i);
700 }
701 }
702
703 pitch_lag = lrintf((idelay[1] + idelay[0]) / 2.0);
704 decode_predictor_coeffs(ilspf, ilpc);
705
706 if (e->bitrate != RATE_QUANT) {
707 acb_excitation(e, e->pitch + ACB_SIZE,
708 e->avg_acb_gain, idelay, subframe_size);
709 for (j = 0; j < subframe_size; j++)
710 e->pitch[ACB_SIZE + j] *= e->fade_scale;
711 e->fade_scale = FFMAX(e->fade_scale - 0.05, 0.0);
712 } else {
713 for (j = 0; j < subframe_size; j++)
714 e->pitch[ACB_SIZE + j] = e->energy_vector[i];
715 }
716
717 memmove(e->pitch, e->pitch + subframe_size, ACB_SIZE * sizeof(float));
718
719 if (e->bitrate != RATE_QUANT && e->avg_acb_gain < 0.4) {
720 f = 0.1 * e->avg_fcb_gain;
721 for (j = 0; j < subframe_size; j++)
722 e->pitch[ACB_SIZE + j] += f;
723 } else if (e->bitrate == RATE_QUANT) {
724 for (j = 0; j < subframe_size; j++)
725 e->pitch[ACB_SIZE + j] = e->energy_vector[i];
726 }
727
728 synthesis_filter(e->pitch + ACB_SIZE, ilpc,
729 e->synthesis, subframe_size, tmp);
730 postfilter(e, tmp, ilpc, samples, pitch_lag,
731 &postfilter_coeffs[e->bitrate], subframe_size);
732
733 samples += subframe_size;
734 }
735}
736
737static int evrc_decode_frame(AVCodecContext *avctx, void *data,
738 int *got_frame_ptr, AVPacket *avpkt)
739{
740 const uint8_t *buf = avpkt->data;
741 AVFrame *frame = data;
742 EVRCContext *e = avctx->priv_data;
743 int buf_size = avpkt->size;
744 float ilspf[FILTER_ORDER], ilpc[FILTER_ORDER], idelay[NB_SUBFRAMES];
745 float *samples;
746 int i, j, ret, error_flag = 0;
747
748 frame->nb_samples = 160;
749 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
750 return ret;
751 samples = (float *)frame->data[0];
752
753 if ((e->bitrate = determine_bitrate(avctx, &buf_size, &buf)) == RATE_ERRS) {
754 warn_insufficient_frame_quality(avctx, "bitrate cannot be determined.");
755 goto erasure;
756 }
757 if (e->bitrate <= SILENCE || e->bitrate == RATE_QUARTER)
758 goto erasure;
759 if (e->bitrate == RATE_QUANT && e->last_valid_bitrate == RATE_FULL
760 && !e->prev_error_flag)
761 goto erasure;
762
763 init_get_bits(&e->gb, buf, 8 * buf_size);
764 memset(&e->frame, 0, sizeof(EVRCAFrame));
765
766 unpack_frame(e);
767
768 if (e->bitrate != RATE_QUANT) {
769 uint8_t *p = (uint8_t *) &e->frame;
770 for (i = 0; i < sizeof(EVRCAFrame); i++) {
771 if (p[i])
772 break;
773 }
774 if (i == sizeof(EVRCAFrame))
775 goto erasure;
776 } else if (e->frame.lsp[0] == 0xf &&
777 e->frame.lsp[1] == 0xf &&
778 e->frame.energy_gain == 0xff) {
779 goto erasure;
780 }
781
782 if (decode_lspf(e) < 0)
783 goto erasure;
784
785 if (e->bitrate == RATE_FULL || e->bitrate == RATE_HALF) {
786 /* Pitch delay parameter checking as per TIA/IS-127 5.1.5.1 */
787 if (e->frame.pitch_delay > MAX_DELAY - MIN_DELAY)
788 goto erasure;
789
790 e->pitch_delay = e->frame.pitch_delay + MIN_DELAY;
791
792 /* Delay diff parameter checking as per TIA/IS-127 5.1.5.2 */
793 if (e->frame.delay_diff) {
794 int p = e->pitch_delay - e->frame.delay_diff + 16;
795 if (p < MIN_DELAY || p > MAX_DELAY)
796 goto erasure;
797 }
798
799 /* Delay contour reconstruction as per TIA/IS-127 5.2.2.2 */
800 if (e->frame.delay_diff &&
801 e->bitrate == RATE_FULL && e->prev_error_flag) {
802 float delay;
803
804 memcpy(e->pitch, e->pitch_back, ACB_SIZE * sizeof(float));
805
806 delay = e->prev_pitch_delay;
807 e->prev_pitch_delay = delay - e->frame.delay_diff + 16.0;
808
809 if (fabs(e->pitch_delay - delay) > 15)
810 delay = e->pitch_delay;
811
812 for (i = 0; i < NB_SUBFRAMES; i++) {
813 int subframe_size = subframe_sizes[i];
814
815 interpolate_delay(idelay, delay, e->prev_pitch_delay, i);
816 acb_excitation(e, e->pitch + ACB_SIZE, e->avg_acb_gain, idelay, subframe_size);
817 memmove(e->pitch, e->pitch + subframe_size, ACB_SIZE * sizeof(float));
818 }
819 }
820
821 /* Smoothing of the decoded delay as per TIA/IS-127 5.2.2.5 */
822 if (fabs(e->pitch_delay - e->prev_pitch_delay) > 15)
823 e->prev_pitch_delay = e->pitch_delay;
824
825 e->avg_acb_gain = e->avg_fcb_gain = 0.0;
826 } else {
827 idelay[0] = idelay[1] = idelay[2] = MIN_DELAY;
828
829 /* Decode frame energy vectors as per TIA/IS-127 5.7.2 */
830 for (i = 0; i < NB_SUBFRAMES; i++)
831 e->energy_vector[i] = pow(10, evrc_energy_quant[e->frame.energy_gain][i]);
832 e->prev_energy_gain = e->frame.energy_gain;
833 }
834
835 for (i = 0; i < NB_SUBFRAMES; i++) {
836 float tmp[SUBFRAME_SIZE + 6] = { 0 };
837 int subframe_size = subframe_sizes[i];
838 int pitch_lag;
839
840 interpolate_lsp(ilspf, e->lspf, e->prev_lspf, i);
841
842 if (e->bitrate != RATE_QUANT)
843 interpolate_delay(idelay, e->pitch_delay, e->prev_pitch_delay, i);
844
845 pitch_lag = lrintf((idelay[1] + idelay[0]) / 2.0);
846 decode_predictor_coeffs(ilspf, ilpc);
847
848 /* Bandwidth expansion as per TIA/IS-127 5.2.3.3 */
849 if (e->frame.lpc_flag && e->prev_error_flag)
850 bandwidth_expansion(ilpc, ilpc, 0.75);
851
852 if (e->bitrate != RATE_QUANT) {
853 float acb_sum, f;
854
855 f = exp((e->bitrate == RATE_HALF ? 0.5 : 0.25)
856 * (e->frame.fcb_gain[i] + 1));
857 acb_sum = pitch_gain_vq[e->frame.acb_gain[i]];
858 e->avg_acb_gain += acb_sum / NB_SUBFRAMES;
859 e->avg_fcb_gain += f / NB_SUBFRAMES;
860
861 acb_excitation(e, e->pitch + ACB_SIZE,
862 acb_sum, idelay, subframe_size);
863 fcb_excitation(e, e->frame.fcb_shape[i], tmp,
864 acb_sum, pitch_lag, subframe_size);
865
866 /* Total excitation generation as per TIA/IS-127 5.2.3.9 */
867 for (j = 0; j < subframe_size; j++)
868 e->pitch[ACB_SIZE + j] += f * tmp[j];
869 e->fade_scale = FFMIN(e->fade_scale + 0.2, 1.0);
870 } else {
871 for (j = 0; j < subframe_size; j++)
872 e->pitch[ACB_SIZE + j] = e->energy_vector[i];
873 }
874
875 memmove(e->pitch, e->pitch + subframe_size, ACB_SIZE * sizeof(float));
876
877 synthesis_filter(e->pitch + ACB_SIZE, ilpc,
878 e->synthesis, subframe_size, tmp);
879 postfilter(e, tmp, ilpc, samples, pitch_lag,
880 &postfilter_coeffs[e->bitrate], subframe_size);
881
882 samples += subframe_size;
883 }
884
885 if (error_flag) {
886erasure:
887 error_flag = 1;
888 av_log(avctx, AV_LOG_WARNING, "frame erasure\n");
889 frame_erasure(e, samples);
890 }
891
892 memcpy(e->prev_lspf, e->lspf, sizeof(e->prev_lspf));
893 e->prev_error_flag = error_flag;
894 e->last_valid_bitrate = e->bitrate;
895
896 if (e->bitrate != RATE_QUANT)
897 e->prev_pitch_delay = e->pitch_delay;
898
899 samples = (float *)frame->data[0];
900 for (i = 0; i < 160; i++)
901 samples[i] /= 32768;
902
903 *got_frame_ptr = 1;
904
905 return avpkt->size;
906}
907
908AVCodec ff_evrc_decoder = {
909 .name = "evrc",
910 .long_name = NULL_IF_CONFIG_SMALL("EVRC (Enhanced Variable Rate Codec)"),
911 .type = AVMEDIA_TYPE_AUDIO,
912 .id = AV_CODEC_ID_EVRC,
913 .init = evrc_decode_init,
914 .decode = evrc_decode_frame,
915 .capabilities = CODEC_CAP_DR1,
916 .priv_data_size = sizeof(EVRCContext),
917};