1 /*
2 * Copyright (c) 2012 Andrew D'Addesio
3 * Copyright (c) 2013-2014 Mozilla Corporation
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 * Opus decoder/parser shared code
25 */
26
27 #include <stdint.h>
28
29 #include "libavutil/error.h"
30 #include "libavutil/ffmath.h"
31
32 #include "opus_celt.h"
33 #include "opustab.h"
34 #include "internal.h"
35 #include "vorbis.h"
36
37 static const uint16_t opus_frame_duration[32] = {
38 480, 960, 1920, 2880,
39 480, 960, 1920, 2880,
40 480, 960, 1920, 2880,
41 480, 960,
42 480, 960,
43 120, 240, 480, 960,
44 120, 240, 480, 960,
45 120, 240, 480, 960,
46 120, 240, 480, 960,
47 };
48
49 /**
50 * Read a 1- or 2-byte frame length
51 */
xiph_lacing_16bit(const uint8_t ** ptr,const uint8_t * end)52 static inline int xiph_lacing_16bit(const uint8_t **ptr, const uint8_t *end)
53 {
54 int val;
55
56 if (*ptr >= end)
57 return AVERROR_INVALIDDATA;
58 val = *(*ptr)++;
59 if (val >= 252) {
60 if (*ptr >= end)
61 return AVERROR_INVALIDDATA;
62 val += 4 * *(*ptr)++;
63 }
64 return val;
65 }
66
67 /**
68 * Read a multi-byte length (used for code 3 packet padding size)
69 */
xiph_lacing_full(const uint8_t ** ptr,const uint8_t * end)70 static inline int xiph_lacing_full(const uint8_t **ptr, const uint8_t *end)
71 {
72 int val = 0;
73 int next;
74
75 while (1) {
76 if (*ptr >= end || val > INT_MAX - 254)
77 return AVERROR_INVALIDDATA;
78 next = *(*ptr)++;
79 val += next;
80 if (next < 255)
81 break;
82 else
83 val--;
84 }
85 return val;
86 }
87
88 /**
89 * Parse Opus packet info from raw packet data
90 */
ff_opus_parse_packet(OpusPacket * pkt,const uint8_t * buf,int buf_size,int self_delimiting)91 int ff_opus_parse_packet(OpusPacket *pkt, const uint8_t *buf, int buf_size,
92 int self_delimiting)
93 {
94 const uint8_t *ptr = buf;
95 const uint8_t *end = buf + buf_size;
96 int padding = 0;
97 int frame_bytes, i;
98
99 if (buf_size < 1)
100 goto fail;
101
102 /* TOC byte */
103 i = *ptr++;
104 pkt->code = (i ) & 0x3;
105 pkt->stereo = (i >> 2) & 0x1;
106 pkt->config = (i >> 3) & 0x1F;
107
108 /* code 2 and code 3 packets have at least 1 byte after the TOC */
109 if (pkt->code >= 2 && buf_size < 2)
110 goto fail;
111
112 switch (pkt->code) {
113 case 0:
114 /* 1 frame */
115 pkt->frame_count = 1;
116 pkt->vbr = 0;
117
118 if (self_delimiting) {
119 int len = xiph_lacing_16bit(&ptr, end);
120 if (len < 0 || len > end - ptr)
121 goto fail;
122 end = ptr + len;
123 buf_size = end - buf;
124 }
125
126 frame_bytes = end - ptr;
127 if (frame_bytes > MAX_FRAME_SIZE)
128 goto fail;
129 pkt->frame_offset[0] = ptr - buf;
130 pkt->frame_size[0] = frame_bytes;
131 break;
132 case 1:
133 /* 2 frames, equal size */
134 pkt->frame_count = 2;
135 pkt->vbr = 0;
136
137 if (self_delimiting) {
138 int len = xiph_lacing_16bit(&ptr, end);
139 if (len < 0 || 2 * len > end - ptr)
140 goto fail;
141 end = ptr + 2 * len;
142 buf_size = end - buf;
143 }
144
145 frame_bytes = end - ptr;
146 if (frame_bytes & 1 || frame_bytes >> 1 > MAX_FRAME_SIZE)
147 goto fail;
148 pkt->frame_offset[0] = ptr - buf;
149 pkt->frame_size[0] = frame_bytes >> 1;
150 pkt->frame_offset[1] = pkt->frame_offset[0] + pkt->frame_size[0];
151 pkt->frame_size[1] = frame_bytes >> 1;
152 break;
153 case 2:
154 /* 2 frames, different sizes */
155 pkt->frame_count = 2;
156 pkt->vbr = 1;
157
158 /* read 1st frame size */
159 frame_bytes = xiph_lacing_16bit(&ptr, end);
160 if (frame_bytes < 0)
161 goto fail;
162
163 if (self_delimiting) {
164 int len = xiph_lacing_16bit(&ptr, end);
165 if (len < 0 || len + frame_bytes > end - ptr)
166 goto fail;
167 end = ptr + frame_bytes + len;
168 buf_size = end - buf;
169 }
170
171 pkt->frame_offset[0] = ptr - buf;
172 pkt->frame_size[0] = frame_bytes;
173
174 /* calculate 2nd frame size */
175 frame_bytes = end - ptr - pkt->frame_size[0];
176 if (frame_bytes < 0 || frame_bytes > MAX_FRAME_SIZE)
177 goto fail;
178 pkt->frame_offset[1] = pkt->frame_offset[0] + pkt->frame_size[0];
179 pkt->frame_size[1] = frame_bytes;
180 break;
181 case 3:
182 /* 1 to 48 frames, can be different sizes */
183 i = *ptr++;
184 pkt->frame_count = (i ) & 0x3F;
185 padding = (i >> 6) & 0x01;
186 pkt->vbr = (i >> 7) & 0x01;
187
188 if (pkt->frame_count == 0 || pkt->frame_count > MAX_FRAMES)
189 goto fail;
190
191 /* read padding size */
192 if (padding) {
193 padding = xiph_lacing_full(&ptr, end);
194 if (padding < 0)
195 goto fail;
196 }
197
198 /* read frame sizes */
199 if (pkt->vbr) {
200 /* for VBR, all frames except the final one have their size coded
201 in the bitstream. the last frame size is implicit. */
202 int total_bytes = 0;
203 for (i = 0; i < pkt->frame_count - 1; i++) {
204 frame_bytes = xiph_lacing_16bit(&ptr, end);
205 if (frame_bytes < 0)
206 goto fail;
207 pkt->frame_size[i] = frame_bytes;
208 total_bytes += frame_bytes;
209 }
210
211 if (self_delimiting) {
212 int len = xiph_lacing_16bit(&ptr, end);
213 if (len < 0 || len + total_bytes + padding > end - ptr)
214 goto fail;
215 end = ptr + total_bytes + len + padding;
216 buf_size = end - buf;
217 }
218
219 frame_bytes = end - ptr - padding;
220 if (total_bytes > frame_bytes)
221 goto fail;
222 pkt->frame_offset[0] = ptr - buf;
223 for (i = 1; i < pkt->frame_count; i++)
224 pkt->frame_offset[i] = pkt->frame_offset[i-1] + pkt->frame_size[i-1];
225 pkt->frame_size[pkt->frame_count-1] = frame_bytes - total_bytes;
226 } else {
227 /* for CBR, the remaining packet bytes are divided evenly between
228 the frames */
229 if (self_delimiting) {
230 frame_bytes = xiph_lacing_16bit(&ptr, end);
231 if (frame_bytes < 0 || pkt->frame_count * frame_bytes + padding > end - ptr)
232 goto fail;
233 end = ptr + pkt->frame_count * frame_bytes + padding;
234 buf_size = end - buf;
235 } else {
236 frame_bytes = end - ptr - padding;
237 if (frame_bytes % pkt->frame_count ||
238 frame_bytes / pkt->frame_count > MAX_FRAME_SIZE)
239 goto fail;
240 frame_bytes /= pkt->frame_count;
241 }
242
243 pkt->frame_offset[0] = ptr - buf;
244 pkt->frame_size[0] = frame_bytes;
245 for (i = 1; i < pkt->frame_count; i++) {
246 pkt->frame_offset[i] = pkt->frame_offset[i-1] + pkt->frame_size[i-1];
247 pkt->frame_size[i] = frame_bytes;
248 }
249 }
250 }
251
252 pkt->packet_size = buf_size;
253 pkt->data_size = pkt->packet_size - padding;
254
255 /* total packet duration cannot be larger than 120ms */
256 pkt->frame_duration = opus_frame_duration[pkt->config];
257 if (pkt->frame_duration * pkt->frame_count > MAX_PACKET_DUR)
258 goto fail;
259
260 /* set mode and bandwidth */
261 if (pkt->config < 12) {
262 pkt->mode = OPUS_MODE_SILK;
263 pkt->bandwidth = pkt->config >> 2;
264 } else if (pkt->config < 16) {
265 pkt->mode = OPUS_MODE_HYBRID;
266 pkt->bandwidth = OPUS_BANDWIDTH_SUPERWIDEBAND + (pkt->config >= 14);
267 } else {
268 pkt->mode = OPUS_MODE_CELT;
269 pkt->bandwidth = (pkt->config - 16) >> 2;
270 /* skip medium band */
271 if (pkt->bandwidth)
272 pkt->bandwidth++;
273 }
274
275 return 0;
276
277 fail:
278 memset(pkt, 0, sizeof(*pkt));
279 return AVERROR_INVALIDDATA;
280 }
281
channel_reorder_vorbis(int nb_channels,int channel_idx)282 static int channel_reorder_vorbis(int nb_channels, int channel_idx)
283 {
284 return ff_vorbis_channel_layout_offsets[nb_channels - 1][channel_idx];
285 }
286
channel_reorder_unknown(int nb_channels,int channel_idx)287 static int channel_reorder_unknown(int nb_channels, int channel_idx)
288 {
289 return channel_idx;
290 }
291
ff_opus_parse_extradata(AVCodecContext * avctx,OpusContext * s)292 av_cold int ff_opus_parse_extradata(AVCodecContext *avctx,
293 OpusContext *s)
294 {
295 static const uint8_t default_channel_map[2] = { 0, 1 };
296
297 int (*channel_reorder)(int, int) = channel_reorder_unknown;
298
299 const uint8_t *extradata, *channel_map;
300 int extradata_size;
301 int version, channels, map_type, streams, stereo_streams, i, j;
302 uint64_t layout;
303
304 if (!avctx->extradata) {
305 if (avctx->channels > 2) {
306 av_log(avctx, AV_LOG_ERROR,
307 "Multichannel configuration without extradata.\n");
308 return AVERROR(EINVAL);
309 }
310 extradata = opus_default_extradata;
311 extradata_size = sizeof(opus_default_extradata);
312 } else {
313 extradata = avctx->extradata;
314 extradata_size = avctx->extradata_size;
315 }
316
317 if (extradata_size < 19) {
318 av_log(avctx, AV_LOG_ERROR, "Invalid extradata size: %d\n",
319 extradata_size);
320 return AVERROR_INVALIDDATA;
321 }
322
323 version = extradata[8];
324 if (version > 15) {
325 avpriv_request_sample(avctx, "Extradata version %d", version);
326 return AVERROR_PATCHWELCOME;
327 }
328
329 avctx->delay = AV_RL16(extradata + 10);
330 if (avctx->internal)
331 avctx->internal->skip_samples = avctx->delay;
332
333 channels = avctx->extradata ? extradata[9] : (avctx->channels == 1) ? 1 : 2;
334 if (!channels) {
335 av_log(avctx, AV_LOG_ERROR, "Zero channel count specified in the extradata\n");
336 return AVERROR_INVALIDDATA;
337 }
338
339 s->gain_i = AV_RL16(extradata + 16);
340 if (s->gain_i)
341 s->gain = ff_exp10(s->gain_i / (20.0 * 256));
342
343 map_type = extradata[18];
344 if (!map_type) {
345 if (channels > 2) {
346 av_log(avctx, AV_LOG_ERROR,
347 "Channel mapping 0 is only specified for up to 2 channels\n");
348 return AVERROR_INVALIDDATA;
349 }
350 layout = (channels == 1) ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
351 streams = 1;
352 stereo_streams = channels - 1;
353 channel_map = default_channel_map;
354 } else if (map_type == 1 || map_type == 2 || map_type == 255) {
355 if (extradata_size < 21 + channels) {
356 av_log(avctx, AV_LOG_ERROR, "Invalid extradata size: %d\n",
357 extradata_size);
358 return AVERROR_INVALIDDATA;
359 }
360
361 streams = extradata[19];
362 stereo_streams = extradata[20];
363 if (!streams || stereo_streams > streams ||
364 streams + stereo_streams > 255) {
365 av_log(avctx, AV_LOG_ERROR,
366 "Invalid stream/stereo stream count: %d/%d\n", streams, stereo_streams);
367 return AVERROR_INVALIDDATA;
368 }
369
370 if (map_type == 1) {
371 if (channels > 8) {
372 av_log(avctx, AV_LOG_ERROR,
373 "Channel mapping 1 is only specified for up to 8 channels\n");
374 return AVERROR_INVALIDDATA;
375 }
376 layout = ff_vorbis_channel_layouts[channels - 1];
377 channel_reorder = channel_reorder_vorbis;
378 } else if (map_type == 2) {
379 int ambisonic_order = ff_sqrt(channels) - 1;
380 if (channels != ((ambisonic_order + 1) * (ambisonic_order + 1)) &&
381 channels != ((ambisonic_order + 1) * (ambisonic_order + 1) + 2)) {
382 av_log(avctx, AV_LOG_ERROR,
383 "Channel mapping 2 is only specified for channel counts"
384 " which can be written as (n + 1)^2 or (n + 1)^2 + 2"
385 " for nonnegative integer n\n");
386 return AVERROR_INVALIDDATA;
387 }
388 if (channels > 227) {
389 av_log(avctx, AV_LOG_ERROR, "Too many channels\n");
390 return AVERROR_INVALIDDATA;
391 }
392 layout = 0;
393 } else
394 layout = 0;
395
396 channel_map = extradata + 21;
397 } else {
398 avpriv_request_sample(avctx, "Mapping type %d", map_type);
399 return AVERROR_PATCHWELCOME;
400 }
401
402 s->channel_maps = av_mallocz_array(channels, sizeof(*s->channel_maps));
403 if (!s->channel_maps)
404 return AVERROR(ENOMEM);
405
406 for (i = 0; i < channels; i++) {
407 ChannelMap *map = &s->channel_maps[i];
408 uint8_t idx = channel_map[channel_reorder(channels, i)];
409
410 if (idx == 255) {
411 map->silence = 1;
412 continue;
413 } else if (idx >= streams + stereo_streams) {
414 av_log(avctx, AV_LOG_ERROR,
415 "Invalid channel map for output channel %d: %d\n", i, idx);
416 av_freep(&s->channel_maps);
417 return AVERROR_INVALIDDATA;
418 }
419
420 /* check that we did not see this index yet */
421 map->copy = 0;
422 for (j = 0; j < i; j++)
423 if (channel_map[channel_reorder(channels, j)] == idx) {
424 map->copy = 1;
425 map->copy_idx = j;
426 break;
427 }
428
429 if (idx < 2 * stereo_streams) {
430 map->stream_idx = idx / 2;
431 map->channel_idx = idx & 1;
432 } else {
433 map->stream_idx = idx - stereo_streams;
434 map->channel_idx = 0;
435 }
436 }
437
438 avctx->channels = channels;
439 avctx->channel_layout = layout;
440 s->nb_streams = streams;
441 s->nb_stereo_streams = stereo_streams;
442
443 return 0;
444 }
445
ff_celt_quant_bands(CeltFrame * f,OpusRangeCoder * rc)446 void ff_celt_quant_bands(CeltFrame *f, OpusRangeCoder *rc)
447 {
448 float lowband_scratch[8 * 22];
449 float norm1[2 * 8 * 100];
450 float *norm2 = norm1 + 8 * 100;
451
452 int totalbits = (f->framebits << 3) - f->anticollapse_needed;
453
454 int update_lowband = 1;
455 int lowband_offset = 0;
456
457 int i, j;
458
459 for (i = f->start_band; i < f->end_band; i++) {
460 uint32_t cm[2] = { (1 << f->blocks) - 1, (1 << f->blocks) - 1 };
461 int band_offset = ff_celt_freq_bands[i] << f->size;
462 int band_size = ff_celt_freq_range[i] << f->size;
463 float *X = f->block[0].coeffs + band_offset;
464 float *Y = (f->channels == 2) ? f->block[1].coeffs + band_offset : NULL;
465 float *norm_loc1, *norm_loc2;
466
467 int consumed = opus_rc_tell_frac(rc);
468 int effective_lowband = -1;
469 int b = 0;
470
471 /* Compute how many bits we want to allocate to this band */
472 if (i != f->start_band)
473 f->remaining -= consumed;
474 f->remaining2 = totalbits - consumed - 1;
475 if (i <= f->coded_bands - 1) {
476 int curr_balance = f->remaining / FFMIN(3, f->coded_bands-i);
477 b = av_clip_uintp2(FFMIN(f->remaining2 + 1, f->pulses[i] + curr_balance), 14);
478 }
479
480 if ((ff_celt_freq_bands[i] - ff_celt_freq_range[i] >= ff_celt_freq_bands[f->start_band] ||
481 i == f->start_band + 1) && (update_lowband || lowband_offset == 0))
482 lowband_offset = i;
483
484 if (i == f->start_band + 1) {
485 /* Special Hybrid Folding (RFC 8251 section 9). Copy the first band into
486 the second to ensure the second band never has to use the LCG. */
487 int count = (ff_celt_freq_range[i] - ff_celt_freq_range[i-1]) << f->size;
488
489 memcpy(&norm1[band_offset], &norm1[band_offset - count], count * sizeof(float));
490
491 if (f->channels == 2)
492 memcpy(&norm2[band_offset], &norm2[band_offset - count], count * sizeof(float));
493 }
494
495 /* Get a conservative estimate of the collapse_mask's for the bands we're
496 going to be folding from. */
497 if (lowband_offset != 0 && (f->spread != CELT_SPREAD_AGGRESSIVE ||
498 f->blocks > 1 || f->tf_change[i] < 0)) {
499 int foldstart, foldend;
500
501 /* This ensures we never repeat spectral content within one band */
502 effective_lowband = FFMAX(ff_celt_freq_bands[f->start_band],
503 ff_celt_freq_bands[lowband_offset] - ff_celt_freq_range[i]);
504 foldstart = lowband_offset;
505 while (ff_celt_freq_bands[--foldstart] > effective_lowband);
506 foldend = lowband_offset - 1;
507 while (++foldend < i && ff_celt_freq_bands[foldend] < effective_lowband + ff_celt_freq_range[i]);
508
509 cm[0] = cm[1] = 0;
510 for (j = foldstart; j < foldend; j++) {
511 cm[0] |= f->block[0].collapse_masks[j];
512 cm[1] |= f->block[f->channels - 1].collapse_masks[j];
513 }
514 }
515
516 if (f->dual_stereo && i == f->intensity_stereo) {
517 /* Switch off dual stereo to do intensity */
518 f->dual_stereo = 0;
519 for (j = ff_celt_freq_bands[f->start_band] << f->size; j < band_offset; j++)
520 norm1[j] = (norm1[j] + norm2[j]) / 2;
521 }
522
523 norm_loc1 = effective_lowband != -1 ? norm1 + (effective_lowband << f->size) : NULL;
524 norm_loc2 = effective_lowband != -1 ? norm2 + (effective_lowband << f->size) : NULL;
525
526 if (f->dual_stereo) {
527 cm[0] = f->pvq->quant_band(f->pvq, f, rc, i, X, NULL, band_size, b >> 1,
528 f->blocks, norm_loc1, f->size,
529 norm1 + band_offset, 0, 1.0f,
530 lowband_scratch, cm[0]);
531
532 cm[1] = f->pvq->quant_band(f->pvq, f, rc, i, Y, NULL, band_size, b >> 1,
533 f->blocks, norm_loc2, f->size,
534 norm2 + band_offset, 0, 1.0f,
535 lowband_scratch, cm[1]);
536 } else {
537 cm[0] = f->pvq->quant_band(f->pvq, f, rc, i, X, Y, band_size, b >> 0,
538 f->blocks, norm_loc1, f->size,
539 norm1 + band_offset, 0, 1.0f,
540 lowband_scratch, cm[0] | cm[1]);
541 cm[1] = cm[0];
542 }
543
544 f->block[0].collapse_masks[i] = (uint8_t)cm[0];
545 f->block[f->channels - 1].collapse_masks[i] = (uint8_t)cm[1];
546 f->remaining += f->pulses[i] + consumed;
547
548 /* Update the folding position only as long as we have 1 bit/sample depth */
549 update_lowband = (b > band_size << 3);
550 }
551 }
552
553 #define NORMC(bits) ((bits) << (f->channels - 1) << f->size >> 2)
554
ff_celt_bitalloc(CeltFrame * f,OpusRangeCoder * rc,int encode)555 void ff_celt_bitalloc(CeltFrame *f, OpusRangeCoder *rc, int encode)
556 {
557 int i, j, low, high, total, done, bandbits, remaining, tbits_8ths;
558 int skip_startband = f->start_band;
559 int skip_bit = 0;
560 int intensitystereo_bit = 0;
561 int dualstereo_bit = 0;
562 int dynalloc = 6;
563 int extrabits = 0;
564
565 int boost[CELT_MAX_BANDS] = { 0 };
566 int trim_offset[CELT_MAX_BANDS];
567 int threshold[CELT_MAX_BANDS];
568 int bits1[CELT_MAX_BANDS];
569 int bits2[CELT_MAX_BANDS];
570
571 /* Spread */
572 if (opus_rc_tell(rc) + 4 <= f->framebits) {
573 if (encode)
574 ff_opus_rc_enc_cdf(rc, f->spread, ff_celt_model_spread);
575 else
576 f->spread = ff_opus_rc_dec_cdf(rc, ff_celt_model_spread);
577 } else {
578 f->spread = CELT_SPREAD_NORMAL;
579 }
580
581 /* Initialize static allocation caps */
582 for (i = 0; i < CELT_MAX_BANDS; i++)
583 f->caps[i] = NORMC((ff_celt_static_caps[f->size][f->channels - 1][i] + 64) * ff_celt_freq_range[i]);
584
585 /* Band boosts */
586 tbits_8ths = f->framebits << 3;
587 for (i = f->start_band; i < f->end_band; i++) {
588 int quanta = ff_celt_freq_range[i] << (f->channels - 1) << f->size;
589 int b_dynalloc = dynalloc;
590 int boost_amount = f->alloc_boost[i];
591 quanta = FFMIN(quanta << 3, FFMAX(6 << 3, quanta));
592
593 while (opus_rc_tell_frac(rc) + (b_dynalloc << 3) < tbits_8ths && boost[i] < f->caps[i]) {
594 int is_boost;
595 if (encode) {
596 is_boost = boost_amount--;
597 ff_opus_rc_enc_log(rc, is_boost, b_dynalloc);
598 } else {
599 is_boost = ff_opus_rc_dec_log(rc, b_dynalloc);
600 }
601
602 if (!is_boost)
603 break;
604
605 boost[i] += quanta;
606 tbits_8ths -= quanta;
607
608 b_dynalloc = 1;
609 }
610
611 if (boost[i])
612 dynalloc = FFMAX(dynalloc - 1, 2);
613 }
614
615 /* Allocation trim */
616 if (!encode)
617 f->alloc_trim = 5;
618 if (opus_rc_tell_frac(rc) + (6 << 3) <= tbits_8ths)
619 if (encode)
620 ff_opus_rc_enc_cdf(rc, f->alloc_trim, ff_celt_model_alloc_trim);
621 else
622 f->alloc_trim = ff_opus_rc_dec_cdf(rc, ff_celt_model_alloc_trim);
623
624 /* Anti-collapse bit reservation */
625 tbits_8ths = (f->framebits << 3) - opus_rc_tell_frac(rc) - 1;
626 f->anticollapse_needed = 0;
627 if (f->transient && f->size >= 2 && tbits_8ths >= ((f->size + 2) << 3))
628 f->anticollapse_needed = 1 << 3;
629 tbits_8ths -= f->anticollapse_needed;
630
631 /* Band skip bit reservation */
632 if (tbits_8ths >= 1 << 3)
633 skip_bit = 1 << 3;
634 tbits_8ths -= skip_bit;
635
636 /* Intensity/dual stereo bit reservation */
637 if (f->channels == 2) {
638 intensitystereo_bit = ff_celt_log2_frac[f->end_band - f->start_band];
639 if (intensitystereo_bit <= tbits_8ths) {
640 tbits_8ths -= intensitystereo_bit;
641 if (tbits_8ths >= 1 << 3) {
642 dualstereo_bit = 1 << 3;
643 tbits_8ths -= 1 << 3;
644 }
645 } else {
646 intensitystereo_bit = 0;
647 }
648 }
649
650 /* Trim offsets */
651 for (i = f->start_band; i < f->end_band; i++) {
652 int trim = f->alloc_trim - 5 - f->size;
653 int band = ff_celt_freq_range[i] * (f->end_band - i - 1);
654 int duration = f->size + 3;
655 int scale = duration + f->channels - 1;
656
657 /* PVQ minimum allocation threshold, below this value the band is
658 * skipped */
659 threshold[i] = FFMAX(3 * ff_celt_freq_range[i] << duration >> 4,
660 f->channels << 3);
661
662 trim_offset[i] = trim * (band << scale) >> 6;
663
664 if (ff_celt_freq_range[i] << f->size == 1)
665 trim_offset[i] -= f->channels << 3;
666 }
667
668 /* Bisection */
669 low = 1;
670 high = CELT_VECTORS - 1;
671 while (low <= high) {
672 int center = (low + high) >> 1;
673 done = total = 0;
674
675 for (i = f->end_band - 1; i >= f->start_band; i--) {
676 bandbits = NORMC(ff_celt_freq_range[i] * ff_celt_static_alloc[center][i]);
677
678 if (bandbits)
679 bandbits = FFMAX(bandbits + trim_offset[i], 0);
680 bandbits += boost[i];
681
682 if (bandbits >= threshold[i] || done) {
683 done = 1;
684 total += FFMIN(bandbits, f->caps[i]);
685 } else if (bandbits >= f->channels << 3) {
686 total += f->channels << 3;
687 }
688 }
689
690 if (total > tbits_8ths)
691 high = center - 1;
692 else
693 low = center + 1;
694 }
695 high = low--;
696
697 /* Bisection */
698 for (i = f->start_band; i < f->end_band; i++) {
699 bits1[i] = NORMC(ff_celt_freq_range[i] * ff_celt_static_alloc[low][i]);
700 bits2[i] = high >= CELT_VECTORS ? f->caps[i] :
701 NORMC(ff_celt_freq_range[i] * ff_celt_static_alloc[high][i]);
702
703 if (bits1[i])
704 bits1[i] = FFMAX(bits1[i] + trim_offset[i], 0);
705 if (bits2[i])
706 bits2[i] = FFMAX(bits2[i] + trim_offset[i], 0);
707
708 if (low)
709 bits1[i] += boost[i];
710 bits2[i] += boost[i];
711
712 if (boost[i])
713 skip_startband = i;
714 bits2[i] = FFMAX(bits2[i] - bits1[i], 0);
715 }
716
717 /* Bisection */
718 low = 0;
719 high = 1 << CELT_ALLOC_STEPS;
720 for (i = 0; i < CELT_ALLOC_STEPS; i++) {
721 int center = (low + high) >> 1;
722 done = total = 0;
723
724 for (j = f->end_band - 1; j >= f->start_band; j--) {
725 bandbits = bits1[j] + (center * bits2[j] >> CELT_ALLOC_STEPS);
726
727 if (bandbits >= threshold[j] || done) {
728 done = 1;
729 total += FFMIN(bandbits, f->caps[j]);
730 } else if (bandbits >= f->channels << 3)
731 total += f->channels << 3;
732 }
733 if (total > tbits_8ths)
734 high = center;
735 else
736 low = center;
737 }
738
739 /* Bisection */
740 done = total = 0;
741 for (i = f->end_band - 1; i >= f->start_band; i--) {
742 bandbits = bits1[i] + (low * bits2[i] >> CELT_ALLOC_STEPS);
743
744 if (bandbits >= threshold[i] || done)
745 done = 1;
746 else
747 bandbits = (bandbits >= f->channels << 3) ?
748 f->channels << 3 : 0;
749
750 bandbits = FFMIN(bandbits, f->caps[i]);
751 f->pulses[i] = bandbits;
752 total += bandbits;
753 }
754
755 /* Band skipping */
756 for (f->coded_bands = f->end_band; ; f->coded_bands--) {
757 int allocation;
758 j = f->coded_bands - 1;
759
760 if (j == skip_startband) {
761 /* all remaining bands are not skipped */
762 tbits_8ths += skip_bit;
763 break;
764 }
765
766 /* determine the number of bits available for coding "do not skip" markers */
767 remaining = tbits_8ths - total;
768 bandbits = remaining / (ff_celt_freq_bands[j+1] - ff_celt_freq_bands[f->start_band]);
769 remaining -= bandbits * (ff_celt_freq_bands[j+1] - ff_celt_freq_bands[f->start_band]);
770 allocation = f->pulses[j] + bandbits * ff_celt_freq_range[j];
771 allocation += FFMAX(remaining - (ff_celt_freq_bands[j] - ff_celt_freq_bands[f->start_band]), 0);
772
773 /* a "do not skip" marker is only coded if the allocation is
774 * above the chosen threshold */
775 if (allocation >= FFMAX(threshold[j], (f->channels + 1) << 3)) {
776 int do_not_skip;
777 if (encode) {
778 do_not_skip = f->coded_bands <= f->skip_band_floor;
779 ff_opus_rc_enc_log(rc, do_not_skip, 1);
780 } else {
781 do_not_skip = ff_opus_rc_dec_log(rc, 1);
782 }
783
784 if (do_not_skip)
785 break;
786
787 total += 1 << 3;
788 allocation -= 1 << 3;
789 }
790
791 /* the band is skipped, so reclaim its bits */
792 total -= f->pulses[j];
793 if (intensitystereo_bit) {
794 total -= intensitystereo_bit;
795 intensitystereo_bit = ff_celt_log2_frac[j - f->start_band];
796 total += intensitystereo_bit;
797 }
798
799 total += f->pulses[j] = (allocation >= f->channels << 3) ? f->channels << 3 : 0;
800 }
801
802 /* IS start band */
803 if (encode) {
804 if (intensitystereo_bit) {
805 f->intensity_stereo = FFMIN(f->intensity_stereo, f->coded_bands);
806 ff_opus_rc_enc_uint(rc, f->intensity_stereo, f->coded_bands + 1 - f->start_band);
807 }
808 } else {
809 f->intensity_stereo = f->dual_stereo = 0;
810 if (intensitystereo_bit)
811 f->intensity_stereo = f->start_band + ff_opus_rc_dec_uint(rc, f->coded_bands + 1 - f->start_band);
812 }
813
814 /* DS flag */
815 if (f->intensity_stereo <= f->start_band)
816 tbits_8ths += dualstereo_bit; /* no intensity stereo means no dual stereo */
817 else if (dualstereo_bit)
818 if (encode)
819 ff_opus_rc_enc_log(rc, f->dual_stereo, 1);
820 else
821 f->dual_stereo = ff_opus_rc_dec_log(rc, 1);
822
823 /* Supply the remaining bits in this frame to lower bands */
824 remaining = tbits_8ths - total;
825 bandbits = remaining / (ff_celt_freq_bands[f->coded_bands] - ff_celt_freq_bands[f->start_band]);
826 remaining -= bandbits * (ff_celt_freq_bands[f->coded_bands] - ff_celt_freq_bands[f->start_band]);
827 for (i = f->start_band; i < f->coded_bands; i++) {
828 const int bits = FFMIN(remaining, ff_celt_freq_range[i]);
829 f->pulses[i] += bits + bandbits * ff_celt_freq_range[i];
830 remaining -= bits;
831 }
832
833 /* Finally determine the allocation */
834 for (i = f->start_band; i < f->coded_bands; i++) {
835 int N = ff_celt_freq_range[i] << f->size;
836 int prev_extra = extrabits;
837 f->pulses[i] += extrabits;
838
839 if (N > 1) {
840 int dof; /* degrees of freedom */
841 int temp; /* dof * channels * log(dof) */
842 int fine_bits;
843 int max_bits;
844 int offset; /* fine energy quantization offset, i.e.
845 * extra bits assigned over the standard
846 * totalbits/dof */
847
848 extrabits = FFMAX(f->pulses[i] - f->caps[i], 0);
849 f->pulses[i] -= extrabits;
850
851 /* intensity stereo makes use of an extra degree of freedom */
852 dof = N * f->channels + (f->channels == 2 && N > 2 && !f->dual_stereo && i < f->intensity_stereo);
853 temp = dof * (ff_celt_log_freq_range[i] + (f->size << 3));
854 offset = (temp >> 1) - dof * CELT_FINE_OFFSET;
855 if (N == 2) /* dof=2 is the only case that doesn't fit the model */
856 offset += dof << 1;
857
858 /* grant an additional bias for the first and second pulses */
859 if (f->pulses[i] + offset < 2 * (dof << 3))
860 offset += temp >> 2;
861 else if (f->pulses[i] + offset < 3 * (dof << 3))
862 offset += temp >> 3;
863
864 fine_bits = (f->pulses[i] + offset + (dof << 2)) / (dof << 3);
865 max_bits = FFMIN((f->pulses[i] >> 3) >> (f->channels - 1), CELT_MAX_FINE_BITS);
866 max_bits = FFMAX(max_bits, 0);
867 f->fine_bits[i] = av_clip(fine_bits, 0, max_bits);
868
869 /* If fine_bits was rounded down or capped,
870 * give priority for the final fine energy pass */
871 f->fine_priority[i] = (f->fine_bits[i] * (dof << 3) >= f->pulses[i] + offset);
872
873 /* the remaining bits are assigned to PVQ */
874 f->pulses[i] -= f->fine_bits[i] << (f->channels - 1) << 3;
875 } else {
876 /* all bits go to fine energy except for the sign bit */
877 extrabits = FFMAX(f->pulses[i] - (f->channels << 3), 0);
878 f->pulses[i] -= extrabits;
879 f->fine_bits[i] = 0;
880 f->fine_priority[i] = 1;
881 }
882
883 /* hand back a limited number of extra fine energy bits to this band */
884 if (extrabits > 0) {
885 int fineextra = FFMIN(extrabits >> (f->channels + 2),
886 CELT_MAX_FINE_BITS - f->fine_bits[i]);
887 f->fine_bits[i] += fineextra;
888
889 fineextra <<= f->channels + 2;
890 f->fine_priority[i] = (fineextra >= extrabits - prev_extra);
891 extrabits -= fineextra;
892 }
893 }
894 f->remaining = extrabits;
895
896 /* skipped bands dedicate all of their bits for fine energy */
897 for (; i < f->end_band; i++) {
898 f->fine_bits[i] = f->pulses[i] >> (f->channels - 1) >> 3;
899 f->pulses[i] = 0;
900 f->fine_priority[i] = f->fine_bits[i] < 1;
901 }
902 }
903