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share sample rate and blocksize tables between the FLAC encoder and FLAC
[FFMpeg-mirror/lagarith.git] / libavcodec / flacenc.c
blob679ad57b97b818d5c41426a5fb0e72632bb90764
1 /**
2 * FLAC audio encoder
3 * Copyright (c) 2006 Justin Ruggles <justin.ruggles@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 #include "libavutil/crc.h"
23 #include "libavutil/lls.h"
24 #include "libavutil/md5.h"
25 #include "avcodec.h"
26 #include "bitstream.h"
27 #include "dsputil.h"
28 #include "golomb.h"
29 #include "lpc.h"
30 #include "flac.h"
31 #include "flacdata.h"
32
33 #define FLAC_SUBFRAME_CONSTANT 0
34 #define FLAC_SUBFRAME_VERBATIM 1
35 #define FLAC_SUBFRAME_FIXED 8
36 #define FLAC_SUBFRAME_LPC 32
37
38 #define MAX_FIXED_ORDER 4
39 #define MAX_PARTITION_ORDER 8
40 #define MAX_PARTITIONS (1 << MAX_PARTITION_ORDER)
41 #define MAX_LPC_PRECISION 15
42 #define MAX_LPC_SHIFT 15
43 #define MAX_RICE_PARAM 14
44
45 typedef struct CompressionOptions {
46 int compression_level;
47 int block_time_ms;
48 int use_lpc;
49 int lpc_coeff_precision;
50 int min_prediction_order;
51 int max_prediction_order;
52 int prediction_order_method;
53 int min_partition_order;
54 int max_partition_order;
55 } CompressionOptions;
56
57 typedef struct RiceContext {
58 int porder;
59 int params[MAX_PARTITIONS];
60 } RiceContext;
61
62 typedef struct FlacSubframe {
63 int type;
64 int type_code;
65 int obits;
66 int order;
67 int32_t coefs[MAX_LPC_ORDER];
68 int shift;
69 RiceContext rc;
70 int32_t samples[FLAC_MAX_BLOCKSIZE];
71 int32_t residual[FLAC_MAX_BLOCKSIZE+1];
72 } FlacSubframe;
73
74 typedef struct FlacFrame {
75 FlacSubframe subframes[FLAC_MAX_CHANNELS];
76 int blocksize;
77 int bs_code[2];
78 uint8_t crc8;
79 int ch_mode;
80 } FlacFrame;
81
82 typedef struct FlacEncodeContext {
83 FLACSTREAMINFO
84 PutBitContext pb;
85 int sr_code[2];
86 int min_framesize;
87 int max_encoded_framesize;
88 uint32_t frame_count;
89 uint64_t sample_count;
90 uint8_t md5sum[16];
91 FlacFrame frame;
92 CompressionOptions options;
93 AVCodecContext *avctx;
94 DSPContext dsp;
95 struct AVMD5 *md5ctx;
96 } FlacEncodeContext;
97
98 /**
99 * Writes streaminfo metadata block to byte array
100 */
101 static void write_streaminfo(FlacEncodeContext *s, uint8_t *header)
102 {
103 PutBitContext pb;
104
105 memset(header, 0, FLAC_STREAMINFO_SIZE);
106 init_put_bits(&pb, header, FLAC_STREAMINFO_SIZE);
107
108 /* streaminfo metadata block */
109 put_bits(&pb, 16, s->avctx->frame_size);
110 put_bits(&pb, 16, s->avctx->frame_size);
111 put_bits(&pb, 24, s->min_framesize);
112 put_bits(&pb, 24, s->max_framesize);
113 put_bits(&pb, 20, s->samplerate);
114 put_bits(&pb, 3, s->channels-1);
115 put_bits(&pb, 5, 15); /* bits per sample - 1 */
116 /* write 36-bit sample count in 2 put_bits() calls */
117 put_bits(&pb, 24, (s->sample_count & 0xFFFFFF000LL) >> 12);
118 put_bits(&pb, 12, s->sample_count & 0x000000FFFLL);
119 flush_put_bits(&pb);
120 memcpy(&header[18], s->md5sum, 16);
121 }
122
123 /**
124 * Sets blocksize based on samplerate
125 * Chooses the closest predefined blocksize >= BLOCK_TIME_MS milliseconds
126 */
127 static int select_blocksize(int samplerate, int block_time_ms)
128 {
129 int i;
130 int target;
131 int blocksize;
132
133 assert(samplerate > 0);
134 blocksize = ff_flac_blocksize_table[1];
135 target = (samplerate * block_time_ms) / 1000;
136 for(i=0; i<16; i++) {
137 if(target >= ff_flac_blocksize_table[i] && ff_flac_blocksize_table[i] > blocksize) {
138 blocksize = ff_flac_blocksize_table[i];
139 }
140 }
141 return blocksize;
142 }
143
144 static av_cold int flac_encode_init(AVCodecContext *avctx)
145 {
146 int freq = avctx->sample_rate;
147 int channels = avctx->channels;
148 FlacEncodeContext *s = avctx->priv_data;
149 int i, level;
150 uint8_t *streaminfo;
151
152 s->avctx = avctx;
153
154 dsputil_init(&s->dsp, avctx);
155
156 if(avctx->sample_fmt != SAMPLE_FMT_S16) {
157 return -1;
158 }
159
160 if(channels < 1 || channels > FLAC_MAX_CHANNELS) {
161 return -1;
162 }
163 s->channels = channels;
164
165 /* find samplerate in table */
166 if(freq < 1)
167 return -1;
168 for(i=4; i<12; i++) {
169 if(freq == ff_flac_sample_rate_table[i]) {
170 s->samplerate = ff_flac_sample_rate_table[i];
171 s->sr_code[0] = i;
172 s->sr_code[1] = 0;
173 break;
174 }
175 }
176 /* if not in table, samplerate is non-standard */
177 if(i == 12) {
178 if(freq % 1000 == 0 && freq < 255000) {
179 s->sr_code[0] = 12;
180 s->sr_code[1] = freq / 1000;
181 } else if(freq % 10 == 0 && freq < 655350) {
182 s->sr_code[0] = 14;
183 s->sr_code[1] = freq / 10;
184 } else if(freq < 65535) {
185 s->sr_code[0] = 13;
186 s->sr_code[1] = freq;
187 } else {
188 return -1;
189 }
190 s->samplerate = freq;
191 }
192
193 /* set compression option defaults based on avctx->compression_level */
194 if(avctx->compression_level < 0) {
195 s->options.compression_level = 5;
196 } else {
197 s->options.compression_level = avctx->compression_level;
198 }
199 av_log(avctx, AV_LOG_DEBUG, " compression: %d\n", s->options.compression_level);
200
201 level= s->options.compression_level;
202 if(level > 12) {
203 av_log(avctx, AV_LOG_ERROR, "invalid compression level: %d\n",
204 s->options.compression_level);
205 return -1;
206 }
207
208 s->options.block_time_ms = ((int[]){ 27, 27, 27,105,105,105,105,105,105,105,105,105,105})[level];
209 s->options.use_lpc = ((int[]){ 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level];
210 s->options.min_prediction_order= ((int[]){ 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level];
211 s->options.max_prediction_order= ((int[]){ 3, 4, 4, 6, 8, 8, 8, 8, 12, 12, 12, 32, 32})[level];
212 s->options.prediction_order_method = ((int[]){ ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
213 ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
214 ORDER_METHOD_4LEVEL, ORDER_METHOD_LOG, ORDER_METHOD_4LEVEL,
215 ORDER_METHOD_LOG, ORDER_METHOD_SEARCH, ORDER_METHOD_LOG,
216 ORDER_METHOD_SEARCH})[level];
217 s->options.min_partition_order = ((int[]){ 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})[level];
218 s->options.max_partition_order = ((int[]){ 2, 2, 3, 3, 3, 8, 8, 8, 8, 8, 8, 8, 8})[level];
219
220 /* set compression option overrides from AVCodecContext */
221 if(avctx->use_lpc >= 0) {
222 s->options.use_lpc = av_clip(avctx->use_lpc, 0, 11);
223 }
224 if(s->options.use_lpc == 1)
225 av_log(avctx, AV_LOG_DEBUG, " use lpc: Levinson-Durbin recursion with Welch window\n");
226 else if(s->options.use_lpc > 1)
227 av_log(avctx, AV_LOG_DEBUG, " use lpc: Cholesky factorization\n");
228
229 if(avctx->min_prediction_order >= 0) {
230 if(s->options.use_lpc) {
231 if(avctx->min_prediction_order < MIN_LPC_ORDER ||
232 avctx->min_prediction_order > MAX_LPC_ORDER) {
233 av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
234 avctx->min_prediction_order);
235 return -1;
236 }
237 } else {
238 if(avctx->min_prediction_order > MAX_FIXED_ORDER) {
239 av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
240 avctx->min_prediction_order);
241 return -1;
242 }
243 }
244 s->options.min_prediction_order = avctx->min_prediction_order;
245 }
246 if(avctx->max_prediction_order >= 0) {
247 if(s->options.use_lpc) {
248 if(avctx->max_prediction_order < MIN_LPC_ORDER ||
249 avctx->max_prediction_order > MAX_LPC_ORDER) {
250 av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
251 avctx->max_prediction_order);
252 return -1;
253 }
254 } else {
255 if(avctx->max_prediction_order > MAX_FIXED_ORDER) {
256 av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
257 avctx->max_prediction_order);
258 return -1;
259 }
260 }
261 s->options.max_prediction_order = avctx->max_prediction_order;
262 }
263 if(s->options.max_prediction_order < s->options.min_prediction_order) {
264 av_log(avctx, AV_LOG_ERROR, "invalid prediction orders: min=%d max=%d\n",
265 s->options.min_prediction_order, s->options.max_prediction_order);
266 return -1;
267 }
268 av_log(avctx, AV_LOG_DEBUG, " prediction order: %d, %d\n",
269 s->options.min_prediction_order, s->options.max_prediction_order);
270
271 if(avctx->prediction_order_method >= 0) {
272 if(avctx->prediction_order_method > ORDER_METHOD_LOG) {
273 av_log(avctx, AV_LOG_ERROR, "invalid prediction order method: %d\n",
274 avctx->prediction_order_method);
275 return -1;
276 }
277 s->options.prediction_order_method = avctx->prediction_order_method;
278 }
279 switch(s->options.prediction_order_method) {
280 case ORDER_METHOD_EST: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
281 "estimate"); break;
282 case ORDER_METHOD_2LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
283 "2-level"); break;
284 case ORDER_METHOD_4LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
285 "4-level"); break;
286 case ORDER_METHOD_8LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
287 "8-level"); break;
288 case ORDER_METHOD_SEARCH: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
289 "full search"); break;
290 case ORDER_METHOD_LOG: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
291 "log search"); break;
292 }
293
294 if(avctx->min_partition_order >= 0) {
295 if(avctx->min_partition_order > MAX_PARTITION_ORDER) {
296 av_log(avctx, AV_LOG_ERROR, "invalid min partition order: %d\n",
297 avctx->min_partition_order);
298 return -1;
299 }
300 s->options.min_partition_order = avctx->min_partition_order;
301 }
302 if(avctx->max_partition_order >= 0) {
303 if(avctx->max_partition_order > MAX_PARTITION_ORDER) {
304 av_log(avctx, AV_LOG_ERROR, "invalid max partition order: %d\n",
305 avctx->max_partition_order);
306 return -1;
307 }
308 s->options.max_partition_order = avctx->max_partition_order;
309 }
310 if(s->options.max_partition_order < s->options.min_partition_order) {
311 av_log(avctx, AV_LOG_ERROR, "invalid partition orders: min=%d max=%d\n",
312 s->options.min_partition_order, s->options.max_partition_order);
313 return -1;
314 }
315 av_log(avctx, AV_LOG_DEBUG, " partition order: %d, %d\n",
316 s->options.min_partition_order, s->options.max_partition_order);
317
318 if(avctx->frame_size > 0) {
319 if(avctx->frame_size < FLAC_MIN_BLOCKSIZE ||
320 avctx->frame_size > FLAC_MAX_BLOCKSIZE) {
321 av_log(avctx, AV_LOG_ERROR, "invalid block size: %d\n",
322 avctx->frame_size);
323 return -1;
324 }
325 } else {
326 s->avctx->frame_size = select_blocksize(s->samplerate, s->options.block_time_ms);
327 }
328 av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", s->avctx->frame_size);
329
330 /* set LPC precision */
331 if(avctx->lpc_coeff_precision > 0) {
332 if(avctx->lpc_coeff_precision > MAX_LPC_PRECISION) {
333 av_log(avctx, AV_LOG_ERROR, "invalid lpc coeff precision: %d\n",
334 avctx->lpc_coeff_precision);
335 return -1;
336 }
337 s->options.lpc_coeff_precision = avctx->lpc_coeff_precision;
338 } else {
339 /* default LPC precision */
340 s->options.lpc_coeff_precision = 15;
341 }
342 av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n",
343 s->options.lpc_coeff_precision);
344
345 /* set maximum encoded frame size in verbatim mode */
346 if(s->channels == 2) {
347 s->max_framesize = 14 + ((s->avctx->frame_size * 33 + 7) >> 3);
348 } else {
349 s->max_framesize = 14 + (s->avctx->frame_size * s->channels * 2);
350 }
351
352 /* initialize MD5 context */
353 s->md5ctx = av_malloc(av_md5_size);
354 if(!s->md5ctx)
355 return AVERROR_NOMEM;
356 av_md5_init(s->md5ctx);
357
358 streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
359 write_streaminfo(s, streaminfo);
360 avctx->extradata = streaminfo;
361 avctx->extradata_size = FLAC_STREAMINFO_SIZE;
362
363 s->frame_count = 0;
364 s->min_framesize = s->max_framesize;
365
366 avctx->coded_frame = avcodec_alloc_frame();
367 avctx->coded_frame->key_frame = 1;
368
369 return 0;
370 }
371
372 static void init_frame(FlacEncodeContext *s)
373 {
374 int i, ch;
375 FlacFrame *frame;
376
377 frame = &s->frame;
378
379 for(i=0; i<16; i++) {
380 if(s->avctx->frame_size == ff_flac_blocksize_table[i]) {
381 frame->blocksize = ff_flac_blocksize_table[i];
382 frame->bs_code[0] = i;
383 frame->bs_code[1] = 0;
384 break;
385 }
386 }
387 if(i == 16) {
388 frame->blocksize = s->avctx->frame_size;
389 if(frame->blocksize <= 256) {
390 frame->bs_code[0] = 6;
391 frame->bs_code[1] = frame->blocksize-1;
392 } else {
393 frame->bs_code[0] = 7;
394 frame->bs_code[1] = frame->blocksize-1;
395 }
396 }
397
398 for(ch=0; ch<s->channels; ch++) {
399 frame->subframes[ch].obits = 16;
400 }
401 }
402
403 /**
404 * Copy channel-interleaved input samples into separate subframes
405 */
406 static void copy_samples(FlacEncodeContext *s, int16_t *samples)
407 {
408 int i, j, ch;
409 FlacFrame *frame;
410
411 frame = &s->frame;
412 for(i=0,j=0; i<frame->blocksize; i++) {
413 for(ch=0; ch<s->channels; ch++,j++) {
414 frame->subframes[ch].samples[i] = samples[j];
415 }
416 }
417 }
418
419
420 #define rice_encode_count(sum, n, k) (((n)*((k)+1))+((sum-(n>>1))>>(k)))
421
422 /**
423 * Solve for d/dk(rice_encode_count) = n-((sum-(n>>1))>>(k+1)) = 0
424 */
425 static int find_optimal_param(uint32_t sum, int n)
426 {
427 int k;
428 uint32_t sum2;
429
430 if(sum <= n>>1)
431 return 0;
432 sum2 = sum-(n>>1);
433 k = av_log2(n<256 ? FASTDIV(sum2,n) : sum2/n);
434 return FFMIN(k, MAX_RICE_PARAM);
435 }
436
437 static uint32_t calc_optimal_rice_params(RiceContext *rc, int porder,
438 uint32_t *sums, int n, int pred_order)
439 {
440 int i;
441 int k, cnt, part;
442 uint32_t all_bits;
443
444 part = (1 << porder);
445 all_bits = 4 * part;
446
447 cnt = (n >> porder) - pred_order;
448 for(i=0; i<part; i++) {
449 k = find_optimal_param(sums[i], cnt);
450 rc->params[i] = k;
451 all_bits += rice_encode_count(sums[i], cnt, k);
452 cnt = n >> porder;
453 }
454
455 rc->porder = porder;
456
457 return all_bits;
458 }
459
460 static void calc_sums(int pmin, int pmax, uint32_t *data, int n, int pred_order,
461 uint32_t sums[][MAX_PARTITIONS])
462 {
463 int i, j;
464 int parts;
465 uint32_t *res, *res_end;
466
467 /* sums for highest level */
468 parts = (1 << pmax);
469 res = &data[pred_order];
470 res_end = &data[n >> pmax];
471 for(i=0; i<parts; i++) {
472 uint32_t sum = 0;
473 while(res < res_end){
474 sum += *(res++);
475 }
476 sums[pmax][i] = sum;
477 res_end+= n >> pmax;
478 }
479 /* sums for lower levels */
480 for(i=pmax-1; i>=pmin; i--) {
481 parts = (1 << i);
482 for(j=0; j<parts; j++) {
483 sums[i][j] = sums[i+1][2*j] + sums[i+1][2*j+1];
484 }
485 }
486 }
487
488 static uint32_t calc_rice_params(RiceContext *rc, int pmin, int pmax,
489 int32_t *data, int n, int pred_order)
490 {
491 int i;
492 uint32_t bits[MAX_PARTITION_ORDER+1];
493 int opt_porder;
494 RiceContext tmp_rc;
495 uint32_t *udata;
496 uint32_t sums[MAX_PARTITION_ORDER+1][MAX_PARTITIONS];
497
498 assert(pmin >= 0 && pmin <= MAX_PARTITION_ORDER);
499 assert(pmax >= 0 && pmax <= MAX_PARTITION_ORDER);
500 assert(pmin <= pmax);
501
502 udata = av_malloc(n * sizeof(uint32_t));
503 for(i=0; i<n; i++) {
504 udata[i] = (2*data[i]) ^ (data[i]>>31);
505 }
506
507 calc_sums(pmin, pmax, udata, n, pred_order, sums);
508
509 opt_porder = pmin;
510 bits[pmin] = UINT32_MAX;
511 for(i=pmin; i<=pmax; i++) {
512 bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums[i], n, pred_order);
513 if(bits[i] <= bits[opt_porder]) {
514 opt_porder = i;
515 *rc= tmp_rc;
516 }
517 }
518
519 av_freep(&udata);
520 return bits[opt_porder];
521 }
522
523 static int get_max_p_order(int max_porder, int n, int order)
524 {
525 int porder = FFMIN(max_porder, av_log2(n^(n-1)));
526 if(order > 0)
527 porder = FFMIN(porder, av_log2(n/order));
528 return porder;
529 }
530
531 static uint32_t calc_rice_params_fixed(RiceContext *rc, int pmin, int pmax,
532 int32_t *data, int n, int pred_order,
533 int bps)
534 {
535 uint32_t bits;
536 pmin = get_max_p_order(pmin, n, pred_order);
537 pmax = get_max_p_order(pmax, n, pred_order);
538 bits = pred_order*bps + 6;
539 bits += calc_rice_params(rc, pmin, pmax, data, n, pred_order);
540 return bits;
541 }
542
543 static uint32_t calc_rice_params_lpc(RiceContext *rc, int pmin, int pmax,
544 int32_t *data, int n, int pred_order,
545 int bps, int precision)
546 {
547 uint32_t bits;
548 pmin = get_max_p_order(pmin, n, pred_order);
549 pmax = get_max_p_order(pmax, n, pred_order);
550 bits = pred_order*bps + 4 + 5 + pred_order*precision + 6;
551 bits += calc_rice_params(rc, pmin, pmax, data, n, pred_order);
552 return bits;
553 }
554
555 /**
556 * Apply Welch window function to audio block
557 */
558 static void apply_welch_window(const int32_t *data, int len, double *w_data)
559 {
560 int i, n2;
561 double w;
562 double c;
563
564 assert(!(len&1)); //the optimization in r11881 does not support odd len
565 //if someone wants odd len extend the change in r11881
566
567 n2 = (len >> 1);
568 c = 2.0 / (len - 1.0);
569
570 w_data+=n2;
571 data+=n2;
572 for(i=0; i<n2; i++) {
573 w = c - n2 + i;
574 w = 1.0 - (w * w);
575 w_data[-i-1] = data[-i-1] * w;
576 w_data[+i ] = data[+i ] * w;
577 }
578 }
579
580 /**
581 * Calculates autocorrelation data from audio samples
582 * A Welch window function is applied before calculation.
583 */
584 void ff_flac_compute_autocorr(const int32_t *data, int len, int lag,
585 double *autoc)
586 {
587 int i, j;
588 double tmp[len + lag + 1];
589 double *data1= tmp + lag;
590
591 apply_welch_window(data, len, data1);
592
593 for(j=0; j<lag; j++)
594 data1[j-lag]= 0.0;
595 data1[len] = 0.0;
596
597 for(j=0; j<lag; j+=2){
598 double sum0 = 1.0, sum1 = 1.0;
599 for(i=0; i<len; i++){
600 sum0 += data1[i] * data1[i-j];
601 sum1 += data1[i] * data1[i-j-1];
602 }
603 autoc[j ] = sum0;
604 autoc[j+1] = sum1;
605 }
606
607 if(j==lag){
608 double sum = 1.0;
609 for(i=0; i<len; i+=2){
610 sum += data1[i ] * data1[i-j ]
611 + data1[i+1] * data1[i-j+1];
612 }
613 autoc[j] = sum;
614 }
615 }
616
617
618 static void encode_residual_verbatim(int32_t *res, int32_t *smp, int n)
619 {
620 assert(n > 0);
621 memcpy(res, smp, n * sizeof(int32_t));
622 }
623
624 static void encode_residual_fixed(int32_t *res, const int32_t *smp, int n,
625 int order)
626 {
627 int i;
628
629 for(i=0; i<order; i++) {
630 res[i] = smp[i];
631 }
632
633 if(order==0){
634 for(i=order; i<n; i++)
635 res[i]= smp[i];
636 }else if(order==1){
637 for(i=order; i<n; i++)
638 res[i]= smp[i] - smp[i-1];
639 }else if(order==2){
640 int a = smp[order-1] - smp[order-2];
641 for(i=order; i<n; i+=2) {
642 int b = smp[i] - smp[i-1];
643 res[i]= b - a;
644 a = smp[i+1] - smp[i];
645 res[i+1]= a - b;
646 }
647 }else if(order==3){
648 int a = smp[order-1] - smp[order-2];
649 int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
650 for(i=order; i<n; i+=2) {
651 int b = smp[i] - smp[i-1];
652 int d = b - a;
653 res[i]= d - c;
654 a = smp[i+1] - smp[i];
655 c = a - b;
656 res[i+1]= c - d;
657 }
658 }else{
659 int a = smp[order-1] - smp[order-2];
660 int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
661 int e = smp[order-1] - 3*smp[order-2] + 3*smp[order-3] - smp[order-4];
662 for(i=order; i<n; i+=2) {
663 int b = smp[i] - smp[i-1];
664 int d = b - a;
665 int f = d - c;
666 res[i]= f - e;
667 a = smp[i+1] - smp[i];
668 c = a - b;
669 e = c - d;
670 res[i+1]= e - f;
671 }
672 }
673 }
674
675 #define LPC1(x) {\
676 int c = coefs[(x)-1];\
677 p0 += c*s;\
678 s = smp[i-(x)+1];\
679 p1 += c*s;\
680 }
681
682 static av_always_inline void encode_residual_lpc_unrolled(
683 int32_t *res, const int32_t *smp, int n,
684 int order, const int32_t *coefs, int shift, int big)
685 {
686 int i;
687 for(i=order; i<n; i+=2) {
688 int s = smp[i-order];
689 int p0 = 0, p1 = 0;
690 if(big) {
691 switch(order) {
692 case 32: LPC1(32)
693 case 31: LPC1(31)
694 case 30: LPC1(30)
695 case 29: LPC1(29)
696 case 28: LPC1(28)
697 case 27: LPC1(27)
698 case 26: LPC1(26)
699 case 25: LPC1(25)
700 case 24: LPC1(24)
701 case 23: LPC1(23)
702 case 22: LPC1(22)
703 case 21: LPC1(21)
704 case 20: LPC1(20)
705 case 19: LPC1(19)
706 case 18: LPC1(18)
707 case 17: LPC1(17)
708 case 16: LPC1(16)
709 case 15: LPC1(15)
710 case 14: LPC1(14)
711 case 13: LPC1(13)
712 case 12: LPC1(12)
713 case 11: LPC1(11)
714 case 10: LPC1(10)
715 case 9: LPC1( 9)
716 LPC1( 8)
717 LPC1( 7)
718 LPC1( 6)
719 LPC1( 5)
720 LPC1( 4)
721 LPC1( 3)
722 LPC1( 2)
723 LPC1( 1)
724 }
725 } else {
726 switch(order) {
727 case 8: LPC1( 8)
728 case 7: LPC1( 7)
729 case 6: LPC1( 6)
730 case 5: LPC1( 5)
731 case 4: LPC1( 4)
732 case 3: LPC1( 3)
733 case 2: LPC1( 2)
734 case 1: LPC1( 1)
735 }
736 }
737 res[i ] = smp[i ] - (p0 >> shift);
738 res[i+1] = smp[i+1] - (p1 >> shift);
739 }
740 }
741
742 static void encode_residual_lpc(int32_t *res, const int32_t *smp, int n,
743 int order, const int32_t *coefs, int shift)
744 {
745 int i;
746 for(i=0; i<order; i++) {
747 res[i] = smp[i];
748 }
749 #if CONFIG_SMALL
750 for(i=order; i<n; i+=2) {
751 int j;
752 int s = smp[i];
753 int p0 = 0, p1 = 0;
754 for(j=0; j<order; j++) {
755 int c = coefs[j];
756 p1 += c*s;
757 s = smp[i-j-1];
758 p0 += c*s;
759 }
760 res[i ] = smp[i ] - (p0 >> shift);
761 res[i+1] = smp[i+1] - (p1 >> shift);
762 }
763 #else
764 switch(order) {
765 case 1: encode_residual_lpc_unrolled(res, smp, n, 1, coefs, shift, 0); break;
766 case 2: encode_residual_lpc_unrolled(res, smp, n, 2, coefs, shift, 0); break;
767 case 3: encode_residual_lpc_unrolled(res, smp, n, 3, coefs, shift, 0); break;
768 case 4: encode_residual_lpc_unrolled(res, smp, n, 4, coefs, shift, 0); break;
769 case 5: encode_residual_lpc_unrolled(res, smp, n, 5, coefs, shift, 0); break;
770 case 6: encode_residual_lpc_unrolled(res, smp, n, 6, coefs, shift, 0); break;
771 case 7: encode_residual_lpc_unrolled(res, smp, n, 7, coefs, shift, 0); break;
772 case 8: encode_residual_lpc_unrolled(res, smp, n, 8, coefs, shift, 0); break;
773 default: encode_residual_lpc_unrolled(res, smp, n, order, coefs, shift, 1); break;
774 }
775 #endif
776 }
777
778 static int encode_residual(FlacEncodeContext *ctx, int ch)
779 {
780 int i, n;
781 int min_order, max_order, opt_order, precision, omethod;
782 int min_porder, max_porder;
783 FlacFrame *frame;
784 FlacSubframe *sub;
785 int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER];
786 int shift[MAX_LPC_ORDER];
787 int32_t *res, *smp;
788
789 frame = &ctx->frame;
790 sub = &frame->subframes[ch];
791 res = sub->residual;
792 smp = sub->samples;
793 n = frame->blocksize;
794
795 /* CONSTANT */
796 for(i=1; i<n; i++) {
797 if(smp[i] != smp[0]) break;
798 }
799 if(i == n) {
800 sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT;
801 res[0] = smp[0];
802 return sub->obits;
803 }
804
805 /* VERBATIM */
806 if(n < 5) {
807 sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM;
808 encode_residual_verbatim(res, smp, n);
809 return sub->obits * n;
810 }
811
812 min_order = ctx->options.min_prediction_order;
813 max_order = ctx->options.max_prediction_order;
814 min_porder = ctx->options.min_partition_order;
815 max_porder = ctx->options.max_partition_order;
816 precision = ctx->options.lpc_coeff_precision;
817 omethod = ctx->options.prediction_order_method;
818
819 /* FIXED */
820 if(!ctx->options.use_lpc || max_order == 0 || (n <= max_order)) {
821 uint32_t bits[MAX_FIXED_ORDER+1];
822 if(max_order > MAX_FIXED_ORDER) max_order = MAX_FIXED_ORDER;
823 opt_order = 0;
824 bits[0] = UINT32_MAX;
825 for(i=min_order; i<=max_order; i++) {
826 encode_residual_fixed(res, smp, n, i);
827 bits[i] = calc_rice_params_fixed(&sub->rc, min_porder, max_porder, res,
828 n, i, sub->obits);
829 if(bits[i] < bits[opt_order]) {
830 opt_order = i;
831 }
832 }
833 sub->order = opt_order;
834 sub->type = FLAC_SUBFRAME_FIXED;
835 sub->type_code = sub->type | sub->order;
836 if(sub->order != max_order) {
837 encode_residual_fixed(res, smp, n, sub->order);
838 return calc_rice_params_fixed(&sub->rc, min_porder, max_porder, res, n,
839 sub->order, sub->obits);
840 }
841 return bits[sub->order];
842 }
843
844 /* LPC */
845 opt_order = ff_lpc_calc_coefs(&ctx->dsp, smp, n, min_order, max_order,
846 precision, coefs, shift, ctx->options.use_lpc,
847 omethod, MAX_LPC_SHIFT, 0);
848
849 if(omethod == ORDER_METHOD_2LEVEL ||
850 omethod == ORDER_METHOD_4LEVEL ||
851 omethod == ORDER_METHOD_8LEVEL) {
852 int levels = 1 << omethod;
853 uint32_t bits[levels];
854 int order;
855 int opt_index = levels-1;
856 opt_order = max_order-1;
857 bits[opt_index] = UINT32_MAX;
858 for(i=levels-1; i>=0; i--) {
859 order = min_order + (((max_order-min_order+1) * (i+1)) / levels)-1;
860 if(order < 0) order = 0;
861 encode_residual_lpc(res, smp, n, order+1, coefs[order], shift[order]);
862 bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder,
863 res, n, order+1, sub->obits, precision);
864 if(bits[i] < bits[opt_index]) {
865 opt_index = i;
866 opt_order = order;
867 }
868 }
869 opt_order++;
870 } else if(omethod == ORDER_METHOD_SEARCH) {
871 // brute-force optimal order search
872 uint32_t bits[MAX_LPC_ORDER];
873 opt_order = 0;
874 bits[0] = UINT32_MAX;
875 for(i=min_order-1; i<max_order; i++) {
876 encode_residual_lpc(res, smp, n, i+1, coefs[i], shift[i]);
877 bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder,
878 res, n, i+1, sub->obits, precision);
879 if(bits[i] < bits[opt_order]) {
880 opt_order = i;
881 }
882 }
883 opt_order++;
884 } else if(omethod == ORDER_METHOD_LOG) {
885 uint32_t bits[MAX_LPC_ORDER];
886 int step;
887
888 opt_order= min_order - 1 + (max_order-min_order)/3;
889 memset(bits, -1, sizeof(bits));
890
891 for(step=16 ;step; step>>=1){
892 int last= opt_order;
893 for(i=last-step; i<=last+step; i+= step){
894 if(i<min_order-1 || i>=max_order || bits[i] < UINT32_MAX)
895 continue;
896 encode_residual_lpc(res, smp, n, i+1, coefs[i], shift[i]);
897 bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder,
898 res, n, i+1, sub->obits, precision);
899 if(bits[i] < bits[opt_order])
900 opt_order= i;
901 }
902 }
903 opt_order++;
904 }
905
906 sub->order = opt_order;
907 sub->type = FLAC_SUBFRAME_LPC;
908 sub->type_code = sub->type | (sub->order-1);
909 sub->shift = shift[sub->order-1];
910 for(i=0; i<sub->order; i++) {
911 sub->coefs[i] = coefs[sub->order-1][i];
912 }
913 encode_residual_lpc(res, smp, n, sub->order, sub->coefs, sub->shift);
914 return calc_rice_params_lpc(&sub->rc, min_porder, max_porder, res, n, sub->order,
915 sub->obits, precision);
916 }
917
918 static int encode_residual_v(FlacEncodeContext *ctx, int ch)
919 {
920 int i, n;
921 FlacFrame *frame;
922 FlacSubframe *sub;
923 int32_t *res, *smp;
924
925 frame = &ctx->frame;
926 sub = &frame->subframes[ch];
927 res = sub->residual;
928 smp = sub->samples;
929 n = frame->blocksize;
930
931 /* CONSTANT */
932 for(i=1; i<n; i++) {
933 if(smp[i] != smp[0]) break;
934 }
935 if(i == n) {
936 sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT;
937 res[0] = smp[0];
938 return sub->obits;
939 }
940
941 /* VERBATIM */
942 sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM;
943 encode_residual_verbatim(res, smp, n);
944 return sub->obits * n;
945 }
946
947 static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n)
948 {
949 int i, best;
950 int32_t lt, rt;
951 uint64_t sum[4];
952 uint64_t score[4];
953 int k;
954
955 /* calculate sum of 2nd order residual for each channel */
956 sum[0] = sum[1] = sum[2] = sum[3] = 0;
957 for(i=2; i<n; i++) {
958 lt = left_ch[i] - 2*left_ch[i-1] + left_ch[i-2];
959 rt = right_ch[i] - 2*right_ch[i-1] + right_ch[i-2];
960 sum[2] += FFABS((lt + rt) >> 1);
961 sum[3] += FFABS(lt - rt);
962 sum[0] += FFABS(lt);
963 sum[1] += FFABS(rt);
964 }
965 /* estimate bit counts */
966 for(i=0; i<4; i++) {
967 k = find_optimal_param(2*sum[i], n);
968 sum[i] = rice_encode_count(2*sum[i], n, k);
969 }
970
971 /* calculate score for each mode */
972 score[0] = sum[0] + sum[1];
973 score[1] = sum[0] + sum[3];
974 score[2] = sum[1] + sum[3];
975 score[3] = sum[2] + sum[3];
976
977 /* return mode with lowest score */
978 best = 0;
979 for(i=1; i<4; i++) {
980 if(score[i] < score[best]) {
981 best = i;
982 }
983 }
984 if(best == 0) {
985 return FLAC_CHMODE_INDEPENDENT;
986 } else if(best == 1) {
987 return FLAC_CHMODE_LEFT_SIDE;
988 } else if(best == 2) {
989 return FLAC_CHMODE_RIGHT_SIDE;
990 } else {
991 return FLAC_CHMODE_MID_SIDE;
992 }
993 }
994
995 /**
996 * Perform stereo channel decorrelation
997 */
998 static void channel_decorrelation(FlacEncodeContext *ctx)
999 {
1000 FlacFrame *frame;
1001 int32_t *left, *right;
1002 int i, n;
1003
1004 frame = &ctx->frame;
1005 n = frame->blocksize;
1006 left = frame->subframes[0].samples;
1007 right = frame->subframes[1].samples;
1008
1009 if(ctx->channels != 2) {
1010 frame->ch_mode = FLAC_CHMODE_INDEPENDENT;
1011 return;
1012 }
1013
1014 frame->ch_mode = estimate_stereo_mode(left, right, n);
1015
1016 /* perform decorrelation and adjust bits-per-sample */
1017 if(frame->ch_mode == FLAC_CHMODE_INDEPENDENT) {
1018 return;
1019 }
1020 if(frame->ch_mode == FLAC_CHMODE_MID_SIDE) {
1021 int32_t tmp;
1022 for(i=0; i<n; i++) {
1023 tmp = left[i];
1024 left[i] = (tmp + right[i]) >> 1;
1025 right[i] = tmp - right[i];
1026 }
1027 frame->subframes[1].obits++;
1028 } else if(frame->ch_mode == FLAC_CHMODE_LEFT_SIDE) {
1029 for(i=0; i<n; i++) {
1030 right[i] = left[i] - right[i];
1031 }
1032 frame->subframes[1].obits++;
1033 } else {
1034 for(i=0; i<n; i++) {
1035 left[i] -= right[i];
1036 }
1037 frame->subframes[0].obits++;
1038 }
1039 }
1040
1041 static void write_utf8(PutBitContext *pb, uint32_t val)
1042 {
1043 uint8_t tmp;
1044 PUT_UTF8(val, tmp, put_bits(pb, 8, tmp);)
1045 }
1046
1047 static void output_frame_header(FlacEncodeContext *s)
1048 {
1049 FlacFrame *frame;
1050 int crc;
1051
1052 frame = &s->frame;
1053
1054 put_bits(&s->pb, 16, 0xFFF8);
1055 put_bits(&s->pb, 4, frame->bs_code[0]);
1056 put_bits(&s->pb, 4, s->sr_code[0]);
1057 if(frame->ch_mode == FLAC_CHMODE_INDEPENDENT) {
1058 put_bits(&s->pb, 4, s->channels-1);
1059 } else {
1060 put_bits(&s->pb, 4, frame->ch_mode);
1061 }
1062 put_bits(&s->pb, 3, 4); /* bits-per-sample code */
1063 put_bits(&s->pb, 1, 0);
1064 write_utf8(&s->pb, s->frame_count);
1065 if(frame->bs_code[0] == 6) {
1066 put_bits(&s->pb, 8, frame->bs_code[1]);
1067 } else if(frame->bs_code[0] == 7) {
1068 put_bits(&s->pb, 16, frame->bs_code[1]);
1069 }
1070 if(s->sr_code[0] == 12) {
1071 put_bits(&s->pb, 8, s->sr_code[1]);
1072 } else if(s->sr_code[0] > 12) {
1073 put_bits(&s->pb, 16, s->sr_code[1]);
1074 }
1075 flush_put_bits(&s->pb);
1076 crc = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0,
1077 s->pb.buf, put_bits_count(&s->pb)>>3);
1078 put_bits(&s->pb, 8, crc);
1079 }
1080
1081 static void output_subframe_constant(FlacEncodeContext *s, int ch)
1082 {
1083 FlacSubframe *sub;
1084 int32_t res;
1085
1086 sub = &s->frame.subframes[ch];
1087 res = sub->residual[0];
1088 put_sbits(&s->pb, sub->obits, res);
1089 }
1090
1091 static void output_subframe_verbatim(FlacEncodeContext *s, int ch)
1092 {
1093 int i;
1094 FlacFrame *frame;
1095 FlacSubframe *sub;
1096 int32_t res;
1097
1098 frame = &s->frame;
1099 sub = &frame->subframes[ch];
1100
1101 for(i=0; i<frame->blocksize; i++) {
1102 res = sub->residual[i];
1103 put_sbits(&s->pb, sub->obits, res);
1104 }
1105 }
1106
1107 static void output_residual(FlacEncodeContext *ctx, int ch)
1108 {
1109 int i, j, p, n, parts;
1110 int k, porder, psize, res_cnt;
1111 FlacFrame *frame;
1112 FlacSubframe *sub;
1113 int32_t *res;
1114
1115 frame = &ctx->frame;
1116 sub = &frame->subframes[ch];
1117 res = sub->residual;
1118 n = frame->blocksize;
1119
1120 /* rice-encoded block */
1121 put_bits(&ctx->pb, 2, 0);
1122
1123 /* partition order */
1124 porder = sub->rc.porder;
1125 psize = n >> porder;
1126 parts = (1 << porder);
1127 put_bits(&ctx->pb, 4, porder);
1128 res_cnt = psize - sub->order;
1129
1130 /* residual */
1131 j = sub->order;
1132 for(p=0; p<parts; p++) {
1133 k = sub->rc.params[p];
1134 put_bits(&ctx->pb, 4, k);
1135 if(p == 1) res_cnt = psize;
1136 for(i=0; i<res_cnt && j<n; i++, j++) {
1137 set_sr_golomb_flac(&ctx->pb, res[j], k, INT32_MAX, 0);
1138 }
1139 }
1140 }
1141
1142 static void output_subframe_fixed(FlacEncodeContext *ctx, int ch)
1143 {
1144 int i;
1145 FlacFrame *frame;
1146 FlacSubframe *sub;
1147
1148 frame = &ctx->frame;
1149 sub = &frame->subframes[ch];
1150
1151 /* warm-up samples */
1152 for(i=0; i<sub->order; i++) {
1153 put_sbits(&ctx->pb, sub->obits, sub->residual[i]);
1154 }
1155
1156 /* residual */
1157 output_residual(ctx, ch);
1158 }
1159
1160 static void output_subframe_lpc(FlacEncodeContext *ctx, int ch)
1161 {
1162 int i, cbits;
1163 FlacFrame *frame;
1164 FlacSubframe *sub;
1165
1166 frame = &ctx->frame;
1167 sub = &frame->subframes[ch];
1168
1169 /* warm-up samples */
1170 for(i=0; i<sub->order; i++) {
1171 put_sbits(&ctx->pb, sub->obits, sub->residual[i]);
1172 }
1173
1174 /* LPC coefficients */
1175 cbits = ctx->options.lpc_coeff_precision;
1176 put_bits(&ctx->pb, 4, cbits-1);
1177 put_sbits(&ctx->pb, 5, sub->shift);
1178 for(i=0; i<sub->order; i++) {
1179 put_sbits(&ctx->pb, cbits, sub->coefs[i]);
1180 }
1181
1182 /* residual */
1183 output_residual(ctx, ch);
1184 }
1185
1186 static void output_subframes(FlacEncodeContext *s)
1187 {
1188 FlacFrame *frame;
1189 FlacSubframe *sub;
1190 int ch;
1191
1192 frame = &s->frame;
1193
1194 for(ch=0; ch<s->channels; ch++) {
1195 sub = &frame->subframes[ch];
1196
1197 /* subframe header */
1198 put_bits(&s->pb, 1, 0);
1199 put_bits(&s->pb, 6, sub->type_code);
1200 put_bits(&s->pb, 1, 0); /* no wasted bits */
1201
1202 /* subframe */
1203 if(sub->type == FLAC_SUBFRAME_CONSTANT) {
1204 output_subframe_constant(s, ch);
1205 } else if(sub->type == FLAC_SUBFRAME_VERBATIM) {
1206 output_subframe_verbatim(s, ch);
1207 } else if(sub->type == FLAC_SUBFRAME_FIXED) {
1208 output_subframe_fixed(s, ch);
1209 } else if(sub->type == FLAC_SUBFRAME_LPC) {
1210 output_subframe_lpc(s, ch);
1211 }
1212 }
1213 }
1214
1215 static void output_frame_footer(FlacEncodeContext *s)
1216 {
1217 int crc;
1218 flush_put_bits(&s->pb);
1219 crc = bswap_16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0,
1220 s->pb.buf, put_bits_count(&s->pb)>>3));
1221 put_bits(&s->pb, 16, crc);
1222 flush_put_bits(&s->pb);
1223 }
1224
1225 static void update_md5_sum(FlacEncodeContext *s, int16_t *samples)
1226 {
1227 #ifdef WORDS_BIGENDIAN
1228 int i;
1229 for(i = 0; i < s->frame.blocksize*s->channels; i++) {
1230 int16_t smp = le2me_16(samples[i]);
1231 av_md5_update(s->md5ctx, (uint8_t *)&smp, 2);
1232 }
1233 #else
1234 av_md5_update(s->md5ctx, (uint8_t *)samples, s->frame.blocksize*s->channels*2);
1235 #endif
1236 }
1237
1238 static int flac_encode_frame(AVCodecContext *avctx, uint8_t *frame,
1239 int buf_size, void *data)
1240 {
1241 int ch;
1242 FlacEncodeContext *s;
1243 int16_t *samples = data;
1244 int out_bytes;
1245 int reencoded=0;
1246
1247 s = avctx->priv_data;
1248
1249 if(buf_size < s->max_framesize*2) {
1250 av_log(avctx, AV_LOG_ERROR, "output buffer too small\n");
1251 return 0;
1252 }
1253
1254 /* when the last block is reached, update the header in extradata */
1255 if (!data) {
1256 s->max_framesize = s->max_encoded_framesize;
1257 av_md5_final(s->md5ctx, s->md5sum);
1258 write_streaminfo(s, avctx->extradata);
1259 return 0;
1260 }
1261
1262 init_frame(s);
1263
1264 copy_samples(s, samples);
1265
1266 channel_decorrelation(s);
1267
1268 for(ch=0; ch<s->channels; ch++) {
1269 encode_residual(s, ch);
1270 }
1271
1272 write_frame:
1273 init_put_bits(&s->pb, frame, buf_size);
1274 output_frame_header(s);
1275 output_subframes(s);
1276 output_frame_footer(s);
1277 out_bytes = put_bits_count(&s->pb) >> 3;
1278
1279 if(out_bytes > s->max_framesize) {
1280 if(reencoded) {
1281 /* still too large. must be an error. */
1282 av_log(avctx, AV_LOG_ERROR, "error encoding frame\n");
1283 return -1;
1284 }
1285
1286 /* frame too large. use verbatim mode */
1287 for(ch=0; ch<s->channels; ch++) {
1288 encode_residual_v(s, ch);
1289 }
1290 reencoded = 1;
1291 goto write_frame;
1292 }
1293
1294 s->frame_count++;
1295 s->sample_count += avctx->frame_size;
1296 update_md5_sum(s, samples);
1297 if (out_bytes > s->max_encoded_framesize)
1298 s->max_encoded_framesize = out_bytes;
1299 if (out_bytes < s->min_framesize)
1300 s->min_framesize = out_bytes;
1301
1302 return out_bytes;
1303 }
1304
1305 static av_cold int flac_encode_close(AVCodecContext *avctx)
1306 {
1307 if (avctx->priv_data) {
1308 FlacEncodeContext *s = avctx->priv_data;
1309 av_freep(&s->md5ctx);
1310 }
1311 av_freep(&avctx->extradata);
1312 avctx->extradata_size = 0;
1313 av_freep(&avctx->coded_frame);
1314 return 0;
1315 }
1316
1317 AVCodec flac_encoder = {
1318 "flac",
1319 CODEC_TYPE_AUDIO,
1320 CODEC_ID_FLAC,
1321 sizeof(FlacEncodeContext),
1322 flac_encode_init,
1323 flac_encode_frame,
1324 flac_encode_close,
1325 NULL,
1326 .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY,
1327 .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
1328 .long_name = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
1329 };
ffmpeg Lagarith lossless decoder