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flacdec: split frame header decoding and validation into a separate
[FFMpeg-mirror/lagarith.git] / libavcodec / flacenc.c
blobb517cfa7206f0a8dbd631cf3d336a919aa6203f6
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 PutBitContext pb;
84 int channels;
85 int samplerate;
86 int sr_code[2];
87 int min_framesize;
88 int max_framesize;
89 int max_encoded_framesize;
90 uint32_t frame_count;
91 uint64_t sample_count;
92 uint8_t md5sum[16];
93 FlacFrame frame;
94 CompressionOptions options;
95 AVCodecContext *avctx;
96 DSPContext dsp;
97 struct AVMD5 *md5ctx;
98 } FlacEncodeContext;
99
100 /**
101 * Writes streaminfo metadata block to byte array
102 */
103 static void write_streaminfo(FlacEncodeContext *s, uint8_t *header)
104 {
105 PutBitContext pb;
106
107 memset(header, 0, FLAC_STREAMINFO_SIZE);
108 init_put_bits(&pb, header, FLAC_STREAMINFO_SIZE);
109
110 /* streaminfo metadata block */
111 put_bits(&pb, 16, s->avctx->frame_size);
112 put_bits(&pb, 16, s->avctx->frame_size);
113 put_bits(&pb, 24, s->min_framesize);
114 put_bits(&pb, 24, s->max_framesize);
115 put_bits(&pb, 20, s->samplerate);
116 put_bits(&pb, 3, s->channels-1);
117 put_bits(&pb, 5, 15); /* bits per sample - 1 */
118 /* write 36-bit sample count in 2 put_bits() calls */
119 put_bits(&pb, 24, (s->sample_count & 0xFFFFFF000LL) >> 12);
120 put_bits(&pb, 12, s->sample_count & 0x000000FFFLL);
121 flush_put_bits(&pb);
122 memcpy(&header[18], s->md5sum, 16);
123 }
124
125 /**
126 * Sets blocksize based on samplerate
127 * Chooses the closest predefined blocksize >= BLOCK_TIME_MS milliseconds
128 */
129 static int select_blocksize(int samplerate, int block_time_ms)
130 {
131 int i;
132 int target;
133 int blocksize;
134
135 assert(samplerate > 0);
136 blocksize = ff_flac_blocksize_table[1];
137 target = (samplerate * block_time_ms) / 1000;
138 for(i=0; i<16; i++) {
139 if(target >= ff_flac_blocksize_table[i] && ff_flac_blocksize_table[i] > blocksize) {
140 blocksize = ff_flac_blocksize_table[i];
141 }
142 }
143 return blocksize;
144 }
145
146 static av_cold int flac_encode_init(AVCodecContext *avctx)
147 {
148 int freq = avctx->sample_rate;
149 int channels = avctx->channels;
150 FlacEncodeContext *s = avctx->priv_data;
151 int i, level;
152 uint8_t *streaminfo;
153
154 s->avctx = avctx;
155
156 dsputil_init(&s->dsp, avctx);
157
158 if(avctx->sample_fmt != SAMPLE_FMT_S16) {
159 return -1;
160 }
161
162 if(channels < 1 || channels > FLAC_MAX_CHANNELS) {
163 return -1;
164 }
165 s->channels = channels;
166
167 /* find samplerate in table */
168 if(freq < 1)
169 return -1;
170 for(i=4; i<12; i++) {
171 if(freq == ff_flac_sample_rate_table[i]) {
172 s->samplerate = ff_flac_sample_rate_table[i];
173 s->sr_code[0] = i;
174 s->sr_code[1] = 0;
175 break;
176 }
177 }
178 /* if not in table, samplerate is non-standard */
179 if(i == 12) {
180 if(freq % 1000 == 0 && freq < 255000) {
181 s->sr_code[0] = 12;
182 s->sr_code[1] = freq / 1000;
183 } else if(freq % 10 == 0 && freq < 655350) {
184 s->sr_code[0] = 14;
185 s->sr_code[1] = freq / 10;
186 } else if(freq < 65535) {
187 s->sr_code[0] = 13;
188 s->sr_code[1] = freq;
189 } else {
190 return -1;
191 }
192 s->samplerate = freq;
193 }
194
195 /* set compression option defaults based on avctx->compression_level */
196 if(avctx->compression_level < 0) {
197 s->options.compression_level = 5;
198 } else {
199 s->options.compression_level = avctx->compression_level;
200 }
201 av_log(avctx, AV_LOG_DEBUG, " compression: %d\n", s->options.compression_level);
202
203 level= s->options.compression_level;
204 if(level > 12) {
205 av_log(avctx, AV_LOG_ERROR, "invalid compression level: %d\n",
206 s->options.compression_level);
207 return -1;
208 }
209
210 s->options.block_time_ms = ((int[]){ 27, 27, 27,105,105,105,105,105,105,105,105,105,105})[level];
211 s->options.use_lpc = ((int[]){ 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level];
212 s->options.min_prediction_order= ((int[]){ 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level];
213 s->options.max_prediction_order= ((int[]){ 3, 4, 4, 6, 8, 8, 8, 8, 12, 12, 12, 32, 32})[level];
214 s->options.prediction_order_method = ((int[]){ ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
215 ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST,
216 ORDER_METHOD_4LEVEL, ORDER_METHOD_LOG, ORDER_METHOD_4LEVEL,
217 ORDER_METHOD_LOG, ORDER_METHOD_SEARCH, ORDER_METHOD_LOG,
218 ORDER_METHOD_SEARCH})[level];
219 s->options.min_partition_order = ((int[]){ 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})[level];
220 s->options.max_partition_order = ((int[]){ 2, 2, 3, 3, 3, 8, 8, 8, 8, 8, 8, 8, 8})[level];
221
222 /* set compression option overrides from AVCodecContext */
223 if(avctx->use_lpc >= 0) {
224 s->options.use_lpc = av_clip(avctx->use_lpc, 0, 11);
225 }
226 if(s->options.use_lpc == 1)
227 av_log(avctx, AV_LOG_DEBUG, " use lpc: Levinson-Durbin recursion with Welch window\n");
228 else if(s->options.use_lpc > 1)
229 av_log(avctx, AV_LOG_DEBUG, " use lpc: Cholesky factorization\n");
230
231 if(avctx->min_prediction_order >= 0) {
232 if(s->options.use_lpc) {
233 if(avctx->min_prediction_order < MIN_LPC_ORDER ||
234 avctx->min_prediction_order > MAX_LPC_ORDER) {
235 av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
236 avctx->min_prediction_order);
237 return -1;
238 }
239 } else {
240 if(avctx->min_prediction_order > MAX_FIXED_ORDER) {
241 av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
242 avctx->min_prediction_order);
243 return -1;
244 }
245 }
246 s->options.min_prediction_order = avctx->min_prediction_order;
247 }
248 if(avctx->max_prediction_order >= 0) {
249 if(s->options.use_lpc) {
250 if(avctx->max_prediction_order < MIN_LPC_ORDER ||
251 avctx->max_prediction_order > MAX_LPC_ORDER) {
252 av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
253 avctx->max_prediction_order);
254 return -1;
255 }
256 } else {
257 if(avctx->max_prediction_order > MAX_FIXED_ORDER) {
258 av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
259 avctx->max_prediction_order);
260 return -1;
261 }
262 }
263 s->options.max_prediction_order = avctx->max_prediction_order;
264 }
265 if(s->options.max_prediction_order < s->options.min_prediction_order) {
266 av_log(avctx, AV_LOG_ERROR, "invalid prediction orders: min=%d max=%d\n",
267 s->options.min_prediction_order, s->options.max_prediction_order);
268 return -1;
269 }
270 av_log(avctx, AV_LOG_DEBUG, " prediction order: %d, %d\n",
271 s->options.min_prediction_order, s->options.max_prediction_order);
272
273 if(avctx->prediction_order_method >= 0) {
274 if(avctx->prediction_order_method > ORDER_METHOD_LOG) {
275 av_log(avctx, AV_LOG_ERROR, "invalid prediction order method: %d\n",
276 avctx->prediction_order_method);
277 return -1;
278 }
279 s->options.prediction_order_method = avctx->prediction_order_method;
280 }
281 switch(s->options.prediction_order_method) {
282 case ORDER_METHOD_EST: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
283 "estimate"); break;
284 case ORDER_METHOD_2LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
285 "2-level"); break;
286 case ORDER_METHOD_4LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
287 "4-level"); break;
288 case ORDER_METHOD_8LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
289 "8-level"); break;
290 case ORDER_METHOD_SEARCH: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
291 "full search"); break;
292 case ORDER_METHOD_LOG: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n",
293 "log search"); break;
294 }
295
296 if(avctx->min_partition_order >= 0) {
297 if(avctx->min_partition_order > MAX_PARTITION_ORDER) {
298 av_log(avctx, AV_LOG_ERROR, "invalid min partition order: %d\n",
299 avctx->min_partition_order);
300 return -1;
301 }
302 s->options.min_partition_order = avctx->min_partition_order;
303 }
304 if(avctx->max_partition_order >= 0) {
305 if(avctx->max_partition_order > MAX_PARTITION_ORDER) {
306 av_log(avctx, AV_LOG_ERROR, "invalid max partition order: %d\n",
307 avctx->max_partition_order);
308 return -1;
309 }
310 s->options.max_partition_order = avctx->max_partition_order;
311 }
312 if(s->options.max_partition_order < s->options.min_partition_order) {
313 av_log(avctx, AV_LOG_ERROR, "invalid partition orders: min=%d max=%d\n",
314 s->options.min_partition_order, s->options.max_partition_order);
315 return -1;
316 }
317 av_log(avctx, AV_LOG_DEBUG, " partition order: %d, %d\n",
318 s->options.min_partition_order, s->options.max_partition_order);
319
320 if(avctx->frame_size > 0) {
321 if(avctx->frame_size < FLAC_MIN_BLOCKSIZE ||
322 avctx->frame_size > FLAC_MAX_BLOCKSIZE) {
323 av_log(avctx, AV_LOG_ERROR, "invalid block size: %d\n",
324 avctx->frame_size);
325 return -1;
326 }
327 } else {
328 s->avctx->frame_size = select_blocksize(s->samplerate, s->options.block_time_ms);
329 }
330 av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", s->avctx->frame_size);
331
332 /* set LPC precision */
333 if(avctx->lpc_coeff_precision > 0) {
334 if(avctx->lpc_coeff_precision > MAX_LPC_PRECISION) {
335 av_log(avctx, AV_LOG_ERROR, "invalid lpc coeff precision: %d\n",
336 avctx->lpc_coeff_precision);
337 return -1;
338 }
339 s->options.lpc_coeff_precision = avctx->lpc_coeff_precision;
340 } else {
341 /* default LPC precision */
342 s->options.lpc_coeff_precision = 15;
343 }
344 av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n",
345 s->options.lpc_coeff_precision);
346
347 /* set maximum encoded frame size in verbatim mode */
348 s->max_framesize = ff_flac_get_max_frame_size(s->avctx->frame_size,
349 s->channels, 16);
350
351 /* initialize MD5 context */
352 s->md5ctx = av_malloc(av_md5_size);
353 if(!s->md5ctx)
354 return AVERROR_NOMEM;
355 av_md5_init(s->md5ctx);
356
357 streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
358 write_streaminfo(s, streaminfo);
359 avctx->extradata = streaminfo;
360 avctx->extradata_size = FLAC_STREAMINFO_SIZE;
361
362 s->frame_count = 0;
363 s->min_framesize = s->max_framesize;
364
365 avctx->coded_frame = avcodec_alloc_frame();
366 avctx->coded_frame->key_frame = 1;
367
368 return 0;
369 }
370
371 static void init_frame(FlacEncodeContext *s)
372 {
373 int i, ch;
374 FlacFrame *frame;
375
376 frame = &s->frame;
377
378 for(i=0; i<16; i++) {
379 if(s->avctx->frame_size == ff_flac_blocksize_table[i]) {
380 frame->blocksize = ff_flac_blocksize_table[i];
381 frame->bs_code[0] = i;
382 frame->bs_code[1] = 0;
383 break;
384 }
385 }
386 if(i == 16) {
387 frame->blocksize = s->avctx->frame_size;
388 if(frame->blocksize <= 256) {
389 frame->bs_code[0] = 6;
390 frame->bs_code[1] = frame->blocksize-1;
391 } else {
392 frame->bs_code[0] = 7;
393 frame->bs_code[1] = frame->blocksize-1;
394 }
395 }
396
397 for(ch=0; ch<s->channels; ch++) {
398 frame->subframes[ch].obits = 16;
399 }
400 }
401
402 /**
403 * Copy channel-interleaved input samples into separate subframes
404 */
405 static void copy_samples(FlacEncodeContext *s, int16_t *samples)
406 {
407 int i, j, ch;
408 FlacFrame *frame;
409
410 frame = &s->frame;
411 for(i=0,j=0; i<frame->blocksize; i++) {
412 for(ch=0; ch<s->channels; ch++,j++) {
413 frame->subframes[ch].samples[i] = samples[j];
414 }
415 }
416 }
417
418
419 #define rice_encode_count(sum, n, k) (((n)*((k)+1))+((sum-(n>>1))>>(k)))
420
421 /**
422 * Solve for d/dk(rice_encode_count) = n-((sum-(n>>1))>>(k+1)) = 0
423 */
424 static int find_optimal_param(uint32_t sum, int n)
425 {
426 int k;
427 uint32_t sum2;
428
429 if(sum <= n>>1)
430 return 0;
431 sum2 = sum-(n>>1);
432 k = av_log2(n<256 ? FASTDIV(sum2,n) : sum2/n);
433 return FFMIN(k, MAX_RICE_PARAM);
434 }
435
436 static uint32_t calc_optimal_rice_params(RiceContext *rc, int porder,
437 uint32_t *sums, int n, int pred_order)
438 {
439 int i;
440 int k, cnt, part;
441 uint32_t all_bits;
442
443 part = (1 << porder);
444 all_bits = 4 * part;
445
446 cnt = (n >> porder) - pred_order;
447 for(i=0; i<part; i++) {
448 k = find_optimal_param(sums[i], cnt);
449 rc->params[i] = k;
450 all_bits += rice_encode_count(sums[i], cnt, k);
451 cnt = n >> porder;
452 }
453
454 rc->porder = porder;
455
456 return all_bits;
457 }
458
459 static void calc_sums(int pmin, int pmax, uint32_t *data, int n, int pred_order,
460 uint32_t sums[][MAX_PARTITIONS])
461 {
462 int i, j;
463 int parts;
464 uint32_t *res, *res_end;
465
466 /* sums for highest level */
467 parts = (1 << pmax);
468 res = &data[pred_order];
469 res_end = &data[n >> pmax];
470 for(i=0; i<parts; i++) {
471 uint32_t sum = 0;
472 while(res < res_end){
473 sum += *(res++);
474 }
475 sums[pmax][i] = sum;
476 res_end+= n >> pmax;
477 }
478 /* sums for lower levels */
479 for(i=pmax-1; i>=pmin; i--) {
480 parts = (1 << i);
481 for(j=0; j<parts; j++) {
482 sums[i][j] = sums[i+1][2*j] + sums[i+1][2*j+1];
483 }
484 }
485 }
486
487 static uint32_t calc_rice_params(RiceContext *rc, int pmin, int pmax,
488 int32_t *data, int n, int pred_order)
489 {
490 int i;
491 uint32_t bits[MAX_PARTITION_ORDER+1];
492 int opt_porder;
493 RiceContext tmp_rc;
494 uint32_t *udata;
495 uint32_t sums[MAX_PARTITION_ORDER+1][MAX_PARTITIONS];
496
497 assert(pmin >= 0 && pmin <= MAX_PARTITION_ORDER);
498 assert(pmax >= 0 && pmax <= MAX_PARTITION_ORDER);
499 assert(pmin <= pmax);
500
501 udata = av_malloc(n * sizeof(uint32_t));
502 for(i=0; i<n; i++) {
503 udata[i] = (2*data[i]) ^ (data[i]>>31);
504 }
505
506 calc_sums(pmin, pmax, udata, n, pred_order, sums);
507
508 opt_porder = pmin;
509 bits[pmin] = UINT32_MAX;
510 for(i=pmin; i<=pmax; i++) {
511 bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums[i], n, pred_order);
512 if(bits[i] <= bits[opt_porder]) {
513 opt_porder = i;
514 *rc= tmp_rc;
515 }
516 }
517
518 av_freep(&udata);
519 return bits[opt_porder];
520 }
521
522 static int get_max_p_order(int max_porder, int n, int order)
523 {
524 int porder = FFMIN(max_porder, av_log2(n^(n-1)));
525 if(order > 0)
526 porder = FFMIN(porder, av_log2(n/order));
527 return porder;
528 }
529
530 static uint32_t calc_rice_params_fixed(RiceContext *rc, int pmin, int pmax,
531 int32_t *data, int n, int pred_order,
532 int bps)
533 {
534 uint32_t bits;
535 pmin = get_max_p_order(pmin, n, pred_order);
536 pmax = get_max_p_order(pmax, n, pred_order);
537 bits = pred_order*bps + 6;
538 bits += calc_rice_params(rc, pmin, pmax, data, n, pred_order);
539 return bits;
540 }
541
542 static uint32_t calc_rice_params_lpc(RiceContext *rc, int pmin, int pmax,
543 int32_t *data, int n, int pred_order,
544 int bps, int precision)
545 {
546 uint32_t bits;
547 pmin = get_max_p_order(pmin, n, pred_order);
548 pmax = get_max_p_order(pmax, n, pred_order);
549 bits = pred_order*bps + 4 + 5 + pred_order*precision + 6;
550 bits += calc_rice_params(rc, pmin, pmax, data, n, pred_order);
551 return bits;
552 }
553
554 /**
555 * Apply Welch window function to audio block
556 */
557 static void apply_welch_window(const int32_t *data, int len, double *w_data)
558 {
559 int i, n2;
560 double w;
561 double c;
562
563 assert(!(len&1)); //the optimization in r11881 does not support odd len
564 //if someone wants odd len extend the change in r11881
565
566 n2 = (len >> 1);
567 c = 2.0 / (len - 1.0);
568
569 w_data+=n2;
570 data+=n2;
571 for(i=0; i<n2; i++) {
572 w = c - n2 + i;
573 w = 1.0 - (w * w);
574 w_data[-i-1] = data[-i-1] * w;
575 w_data[+i ] = data[+i ] * w;
576 }
577 }
578
579 /**
580 * Calculates autocorrelation data from audio samples
581 * A Welch window function is applied before calculation.
582 */
583 void ff_flac_compute_autocorr(const int32_t *data, int len, int lag,
584 double *autoc)
585 {
586 int i, j;
587 double tmp[len + lag + 1];
588 double *data1= tmp + lag;
589
590 apply_welch_window(data, len, data1);
591
592 for(j=0; j<lag; j++)
593 data1[j-lag]= 0.0;
594 data1[len] = 0.0;
595
596 for(j=0; j<lag; j+=2){
597 double sum0 = 1.0, sum1 = 1.0;
598 for(i=0; i<len; i++){
599 sum0 += data1[i] * data1[i-j];
600 sum1 += data1[i] * data1[i-j-1];
601 }
602 autoc[j ] = sum0;
603 autoc[j+1] = sum1;
604 }
605
606 if(j==lag){
607 double sum = 1.0;
608 for(i=0; i<len; i+=2){
609 sum += data1[i ] * data1[i-j ]
610 + data1[i+1] * data1[i-j+1];
611 }
612 autoc[j] = sum;
613 }
614 }
615
616
617 static void encode_residual_verbatim(int32_t *res, int32_t *smp, int n)
618 {
619 assert(n > 0);
620 memcpy(res, smp, n * sizeof(int32_t));
621 }
622
623 static void encode_residual_fixed(int32_t *res, const int32_t *smp, int n,
624 int order)
625 {
626 int i;
627
628 for(i=0; i<order; i++) {
629 res[i] = smp[i];
630 }
631
632 if(order==0){
633 for(i=order; i<n; i++)
634 res[i]= smp[i];
635 }else if(order==1){
636 for(i=order; i<n; i++)
637 res[i]= smp[i] - smp[i-1];
638 }else if(order==2){
639 int a = smp[order-1] - smp[order-2];
640 for(i=order; i<n; i+=2) {
641 int b = smp[i] - smp[i-1];
642 res[i]= b - a;
643 a = smp[i+1] - smp[i];
644 res[i+1]= a - b;
645 }
646 }else if(order==3){
647 int a = smp[order-1] - smp[order-2];
648 int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
649 for(i=order; i<n; i+=2) {
650 int b = smp[i] - smp[i-1];
651 int d = b - a;
652 res[i]= d - c;
653 a = smp[i+1] - smp[i];
654 c = a - b;
655 res[i+1]= c - d;
656 }
657 }else{
658 int a = smp[order-1] - smp[order-2];
659 int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
660 int e = smp[order-1] - 3*smp[order-2] + 3*smp[order-3] - smp[order-4];
661 for(i=order; i<n; i+=2) {
662 int b = smp[i] - smp[i-1];
663 int d = b - a;
664 int f = d - c;
665 res[i]= f - e;
666 a = smp[i+1] - smp[i];
667 c = a - b;
668 e = c - d;
669 res[i+1]= e - f;
670 }
671 }
672 }
673
674 #define LPC1(x) {\
675 int c = coefs[(x)-1];\
676 p0 += c*s;\
677 s = smp[i-(x)+1];\
678 p1 += c*s;\
679 }
680
681 static av_always_inline void encode_residual_lpc_unrolled(
682 int32_t *res, const int32_t *smp, int n,
683 int order, const int32_t *coefs, int shift, int big)
684 {
685 int i;
686 for(i=order; i<n; i+=2) {
687 int s = smp[i-order];
688 int p0 = 0, p1 = 0;
689 if(big) {
690 switch(order) {
691 case 32: LPC1(32)
692 case 31: LPC1(31)
693 case 30: LPC1(30)
694 case 29: LPC1(29)
695 case 28: LPC1(28)
696 case 27: LPC1(27)
697 case 26: LPC1(26)
698 case 25: LPC1(25)
699 case 24: LPC1(24)
700 case 23: LPC1(23)
701 case 22: LPC1(22)
702 case 21: LPC1(21)
703 case 20: LPC1(20)
704 case 19: LPC1(19)
705 case 18: LPC1(18)
706 case 17: LPC1(17)
707 case 16: LPC1(16)
708 case 15: LPC1(15)
709 case 14: LPC1(14)
710 case 13: LPC1(13)
711 case 12: LPC1(12)
712 case 11: LPC1(11)
713 case 10: LPC1(10)
714 case 9: LPC1( 9)
715 LPC1( 8)
716 LPC1( 7)
717 LPC1( 6)
718 LPC1( 5)
719 LPC1( 4)
720 LPC1( 3)
721 LPC1( 2)
722 LPC1( 1)
723 }
724 } else {
725 switch(order) {
726 case 8: LPC1( 8)
727 case 7: LPC1( 7)
728 case 6: LPC1( 6)
729 case 5: LPC1( 5)
730 case 4: LPC1( 4)
731 case 3: LPC1( 3)
732 case 2: LPC1( 2)
733 case 1: LPC1( 1)
734 }
735 }
736 res[i ] = smp[i ] - (p0 >> shift);
737 res[i+1] = smp[i+1] - (p1 >> shift);
738 }
739 }
740
741 static void encode_residual_lpc(int32_t *res, const int32_t *smp, int n,
742 int order, const int32_t *coefs, int shift)
743 {
744 int i;
745 for(i=0; i<order; i++) {
746 res[i] = smp[i];
747 }
748 #if CONFIG_SMALL
749 for(i=order; i<n; i+=2) {
750 int j;
751 int s = smp[i];
752 int p0 = 0, p1 = 0;
753 for(j=0; j<order; j++) {
754 int c = coefs[j];
755 p1 += c*s;
756 s = smp[i-j-1];
757 p0 += c*s;
758 }
759 res[i ] = smp[i ] - (p0 >> shift);
760 res[i+1] = smp[i+1] - (p1 >> shift);
761 }
762 #else
763 switch(order) {
764 case 1: encode_residual_lpc_unrolled(res, smp, n, 1, coefs, shift, 0); break;
765 case 2: encode_residual_lpc_unrolled(res, smp, n, 2, coefs, shift, 0); break;
766 case 3: encode_residual_lpc_unrolled(res, smp, n, 3, coefs, shift, 0); break;
767 case 4: encode_residual_lpc_unrolled(res, smp, n, 4, coefs, shift, 0); break;
768 case 5: encode_residual_lpc_unrolled(res, smp, n, 5, coefs, shift, 0); break;
769 case 6: encode_residual_lpc_unrolled(res, smp, n, 6, coefs, shift, 0); break;
770 case 7: encode_residual_lpc_unrolled(res, smp, n, 7, coefs, shift, 0); break;
771 case 8: encode_residual_lpc_unrolled(res, smp, n, 8, coefs, shift, 0); break;
772 default: encode_residual_lpc_unrolled(res, smp, n, order, coefs, shift, 1); break;
773 }
774 #endif
775 }
776
777 static int encode_residual(FlacEncodeContext *ctx, int ch)
778 {
779 int i, n;
780 int min_order, max_order, opt_order, precision, omethod;
781 int min_porder, max_porder;
782 FlacFrame *frame;
783 FlacSubframe *sub;
784 int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER];
785 int shift[MAX_LPC_ORDER];
786 int32_t *res, *smp;
787
788 frame = &ctx->frame;
789 sub = &frame->subframes[ch];
790 res = sub->residual;
791 smp = sub->samples;
792 n = frame->blocksize;
793
794 /* CONSTANT */
795 for(i=1; i<n; i++) {
796 if(smp[i] != smp[0]) break;
797 }
798 if(i == n) {
799 sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT;
800 res[0] = smp[0];
801 return sub->obits;
802 }
803
804 /* VERBATIM */
805 if(n < 5) {
806 sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM;
807 encode_residual_verbatim(res, smp, n);
808 return sub->obits * n;
809 }
810
811 min_order = ctx->options.min_prediction_order;
812 max_order = ctx->options.max_prediction_order;
813 min_porder = ctx->options.min_partition_order;
814 max_porder = ctx->options.max_partition_order;
815 precision = ctx->options.lpc_coeff_precision;
816 omethod = ctx->options.prediction_order_method;
817
818 /* FIXED */
819 if(!ctx->options.use_lpc || max_order == 0 || (n <= max_order)) {
820 uint32_t bits[MAX_FIXED_ORDER+1];
821 if(max_order > MAX_FIXED_ORDER) max_order = MAX_FIXED_ORDER;
822 opt_order = 0;
823 bits[0] = UINT32_MAX;
824 for(i=min_order; i<=max_order; i++) {
825 encode_residual_fixed(res, smp, n, i);
826 bits[i] = calc_rice_params_fixed(&sub->rc, min_porder, max_porder, res,
827 n, i, sub->obits);
828 if(bits[i] < bits[opt_order]) {
829 opt_order = i;
830 }
831 }
832 sub->order = opt_order;
833 sub->type = FLAC_SUBFRAME_FIXED;
834 sub->type_code = sub->type | sub->order;
835 if(sub->order != max_order) {
836 encode_residual_fixed(res, smp, n, sub->order);
837 return calc_rice_params_fixed(&sub->rc, min_porder, max_porder, res, n,
838 sub->order, sub->obits);
839 }
840 return bits[sub->order];
841 }
842
843 /* LPC */
844 opt_order = ff_lpc_calc_coefs(&ctx->dsp, smp, n, min_order, max_order,
845 precision, coefs, shift, ctx->options.use_lpc,
846 omethod, MAX_LPC_SHIFT, 0);
847
848 if(omethod == ORDER_METHOD_2LEVEL ||
849 omethod == ORDER_METHOD_4LEVEL ||
850 omethod == ORDER_METHOD_8LEVEL) {
851 int levels = 1 << omethod;
852 uint32_t bits[levels];
853 int order;
854 int opt_index = levels-1;
855 opt_order = max_order-1;
856 bits[opt_index] = UINT32_MAX;
857 for(i=levels-1; i>=0; i--) {
858 order = min_order + (((max_order-min_order+1) * (i+1)) / levels)-1;
859 if(order < 0) order = 0;
860 encode_residual_lpc(res, smp, n, order+1, coefs[order], shift[order]);
861 bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder,
862 res, n, order+1, sub->obits, precision);
863 if(bits[i] < bits[opt_index]) {
864 opt_index = i;
865 opt_order = order;
866 }
867 }
868 opt_order++;
869 } else if(omethod == ORDER_METHOD_SEARCH) {
870 // brute-force optimal order search
871 uint32_t bits[MAX_LPC_ORDER];
872 opt_order = 0;
873 bits[0] = UINT32_MAX;
874 for(i=min_order-1; i<max_order; i++) {
875 encode_residual_lpc(res, smp, n, i+1, coefs[i], shift[i]);
876 bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder,
877 res, n, i+1, sub->obits, precision);
878 if(bits[i] < bits[opt_order]) {
879 opt_order = i;
880 }
881 }
882 opt_order++;
883 } else if(omethod == ORDER_METHOD_LOG) {
884 uint32_t bits[MAX_LPC_ORDER];
885 int step;
886
887 opt_order= min_order - 1 + (max_order-min_order)/3;
888 memset(bits, -1, sizeof(bits));
889
890 for(step=16 ;step; step>>=1){
891 int last= opt_order;
892 for(i=last-step; i<=last+step; i+= step){
893 if(i<min_order-1 || i>=max_order || bits[i] < UINT32_MAX)
894 continue;
895 encode_residual_lpc(res, smp, n, i+1, coefs[i], shift[i]);
896 bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder,
897 res, n, i+1, sub->obits, precision);
898 if(bits[i] < bits[opt_order])
899 opt_order= i;
900 }
901 }
902 opt_order++;
903 }
904
905 sub->order = opt_order;
906 sub->type = FLAC_SUBFRAME_LPC;
907 sub->type_code = sub->type | (sub->order-1);
908 sub->shift = shift[sub->order-1];
909 for(i=0; i<sub->order; i++) {
910 sub->coefs[i] = coefs[sub->order-1][i];
911 }
912 encode_residual_lpc(res, smp, n, sub->order, sub->coefs, sub->shift);
913 return calc_rice_params_lpc(&sub->rc, min_porder, max_porder, res, n, sub->order,
914 sub->obits, precision);
915 }
916
917 static int encode_residual_v(FlacEncodeContext *ctx, int ch)
918 {
919 int i, n;
920 FlacFrame *frame;
921 FlacSubframe *sub;
922 int32_t *res, *smp;
923
924 frame = &ctx->frame;
925 sub = &frame->subframes[ch];
926 res = sub->residual;
927 smp = sub->samples;
928 n = frame->blocksize;
929
930 /* CONSTANT */
931 for(i=1; i<n; i++) {
932 if(smp[i] != smp[0]) break;
933 }
934 if(i == n) {
935 sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT;
936 res[0] = smp[0];
937 return sub->obits;
938 }
939
940 /* VERBATIM */
941 sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM;
942 encode_residual_verbatim(res, smp, n);
943 return sub->obits * n;
944 }
945
946 static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n)
947 {
948 int i, best;
949 int32_t lt, rt;
950 uint64_t sum[4];
951 uint64_t score[4];
952 int k;
953
954 /* calculate sum of 2nd order residual for each channel */
955 sum[0] = sum[1] = sum[2] = sum[3] = 0;
956 for(i=2; i<n; i++) {
957 lt = left_ch[i] - 2*left_ch[i-1] + left_ch[i-2];
958 rt = right_ch[i] - 2*right_ch[i-1] + right_ch[i-2];
959 sum[2] += FFABS((lt + rt) >> 1);
960 sum[3] += FFABS(lt - rt);
961 sum[0] += FFABS(lt);
962 sum[1] += FFABS(rt);
963 }
964 /* estimate bit counts */
965 for(i=0; i<4; i++) {
966 k = find_optimal_param(2*sum[i], n);
967 sum[i] = rice_encode_count(2*sum[i], n, k);
968 }
969
970 /* calculate score for each mode */
971 score[0] = sum[0] + sum[1];
972 score[1] = sum[0] + sum[3];
973 score[2] = sum[1] + sum[3];
974 score[3] = sum[2] + sum[3];
975
976 /* return mode with lowest score */
977 best = 0;
978 for(i=1; i<4; i++) {
979 if(score[i] < score[best]) {
980 best = i;
981 }
982 }
983 if(best == 0) {
984 return FLAC_CHMODE_INDEPENDENT;
985 } else if(best == 1) {
986 return FLAC_CHMODE_LEFT_SIDE;
987 } else if(best == 2) {
988 return FLAC_CHMODE_RIGHT_SIDE;
989 } else {
990 return FLAC_CHMODE_MID_SIDE;
991 }
992 }
993
994 /**
995 * Perform stereo channel decorrelation
996 */
997 static void channel_decorrelation(FlacEncodeContext *ctx)
998 {
999 FlacFrame *frame;
1000 int32_t *left, *right;
1001 int i, n;
1002
1003 frame = &ctx->frame;
1004 n = frame->blocksize;
1005 left = frame->subframes[0].samples;
1006 right = frame->subframes[1].samples;
1007
1008 if(ctx->channels != 2) {
1009 frame->ch_mode = FLAC_CHMODE_INDEPENDENT;
1010 return;
1011 }
1012
1013 frame->ch_mode = estimate_stereo_mode(left, right, n);
1014
1015 /* perform decorrelation and adjust bits-per-sample */
1016 if(frame->ch_mode == FLAC_CHMODE_INDEPENDENT) {
1017 return;
1018 }
1019 if(frame->ch_mode == FLAC_CHMODE_MID_SIDE) {
1020 int32_t tmp;
1021 for(i=0; i<n; i++) {
1022 tmp = left[i];
1023 left[i] = (tmp + right[i]) >> 1;
1024 right[i] = tmp - right[i];
1025 }
1026 frame->subframes[1].obits++;
1027 } else if(frame->ch_mode == FLAC_CHMODE_LEFT_SIDE) {
1028 for(i=0; i<n; i++) {
1029 right[i] = left[i] - right[i];
1030 }
1031 frame->subframes[1].obits++;
1032 } else {
1033 for(i=0; i<n; i++) {
1034 left[i] -= right[i];
1035 }
1036 frame->subframes[0].obits++;
1037 }
1038 }
1039
1040 static void write_utf8(PutBitContext *pb, uint32_t val)
1041 {
1042 uint8_t tmp;
1043 PUT_UTF8(val, tmp, put_bits(pb, 8, tmp);)
1044 }
1045
1046 static void output_frame_header(FlacEncodeContext *s)
1047 {
1048 FlacFrame *frame;
1049 int crc;
1050
1051 frame = &s->frame;
1052
1053 put_bits(&s->pb, 16, 0xFFF8);
1054 put_bits(&s->pb, 4, frame->bs_code[0]);
1055 put_bits(&s->pb, 4, s->sr_code[0]);
1056 if(frame->ch_mode == FLAC_CHMODE_INDEPENDENT) {
1057 put_bits(&s->pb, 4, s->channels-1);
1058 } else {
1059 put_bits(&s->pb, 4, frame->ch_mode);
1060 }
1061 put_bits(&s->pb, 3, 4); /* bits-per-sample code */
1062 put_bits(&s->pb, 1, 0);
1063 write_utf8(&s->pb, s->frame_count);
1064 if(frame->bs_code[0] == 6) {
1065 put_bits(&s->pb, 8, frame->bs_code[1]);
1066 } else if(frame->bs_code[0] == 7) {
1067 put_bits(&s->pb, 16, frame->bs_code[1]);
1068 }
1069 if(s->sr_code[0] == 12) {
1070 put_bits(&s->pb, 8, s->sr_code[1]);
1071 } else if(s->sr_code[0] > 12) {
1072 put_bits(&s->pb, 16, s->sr_code[1]);
1073 }
1074 flush_put_bits(&s->pb);
1075 crc = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0,
1076 s->pb.buf, put_bits_count(&s->pb)>>3);
1077 put_bits(&s->pb, 8, crc);
1078 }
1079
1080 static void output_subframe_constant(FlacEncodeContext *s, int ch)
1081 {
1082 FlacSubframe *sub;
1083 int32_t res;
1084
1085 sub = &s->frame.subframes[ch];
1086 res = sub->residual[0];
1087 put_sbits(&s->pb, sub->obits, res);
1088 }
1089
1090 static void output_subframe_verbatim(FlacEncodeContext *s, int ch)
1091 {
1092 int i;
1093 FlacFrame *frame;
1094 FlacSubframe *sub;
1095 int32_t res;
1096
1097 frame = &s->frame;
1098 sub = &frame->subframes[ch];
1099
1100 for(i=0; i<frame->blocksize; i++) {
1101 res = sub->residual[i];
1102 put_sbits(&s->pb, sub->obits, res);
1103 }
1104 }
1105
1106 static void output_residual(FlacEncodeContext *ctx, int ch)
1107 {
1108 int i, j, p, n, parts;
1109 int k, porder, psize, res_cnt;
1110 FlacFrame *frame;
1111 FlacSubframe *sub;
1112 int32_t *res;
1113
1114 frame = &ctx->frame;
1115 sub = &frame->subframes[ch];
1116 res = sub->residual;
1117 n = frame->blocksize;
1118
1119 /* rice-encoded block */
1120 put_bits(&ctx->pb, 2, 0);
1121
1122 /* partition order */
1123 porder = sub->rc.porder;
1124 psize = n >> porder;
1125 parts = (1 << porder);
1126 put_bits(&ctx->pb, 4, porder);
1127 res_cnt = psize - sub->order;
1128
1129 /* residual */
1130 j = sub->order;
1131 for(p=0; p<parts; p++) {
1132 k = sub->rc.params[p];
1133 put_bits(&ctx->pb, 4, k);
1134 if(p == 1) res_cnt = psize;
1135 for(i=0; i<res_cnt && j<n; i++, j++) {
1136 set_sr_golomb_flac(&ctx->pb, res[j], k, INT32_MAX, 0);
1137 }
1138 }
1139 }
1140
1141 static void output_subframe_fixed(FlacEncodeContext *ctx, int ch)
1142 {
1143 int i;
1144 FlacFrame *frame;
1145 FlacSubframe *sub;
1146
1147 frame = &ctx->frame;
1148 sub = &frame->subframes[ch];
1149
1150 /* warm-up samples */
1151 for(i=0; i<sub->order; i++) {
1152 put_sbits(&ctx->pb, sub->obits, sub->residual[i]);
1153 }
1154
1155 /* residual */
1156 output_residual(ctx, ch);
1157 }
1158
1159 static void output_subframe_lpc(FlacEncodeContext *ctx, int ch)
1160 {
1161 int i, cbits;
1162 FlacFrame *frame;
1163 FlacSubframe *sub;
1164
1165 frame = &ctx->frame;
1166 sub = &frame->subframes[ch];
1167
1168 /* warm-up samples */
1169 for(i=0; i<sub->order; i++) {
1170 put_sbits(&ctx->pb, sub->obits, sub->residual[i]);
1171 }
1172
1173 /* LPC coefficients */
1174 cbits = ctx->options.lpc_coeff_precision;
1175 put_bits(&ctx->pb, 4, cbits-1);
1176 put_sbits(&ctx->pb, 5, sub->shift);
1177 for(i=0; i<sub->order; i++) {
1178 put_sbits(&ctx->pb, cbits, sub->coefs[i]);
1179 }
1180
1181 /* residual */
1182 output_residual(ctx, ch);
1183 }
1184
1185 static void output_subframes(FlacEncodeContext *s)
1186 {
1187 FlacFrame *frame;
1188 FlacSubframe *sub;
1189 int ch;
1190
1191 frame = &s->frame;
1192
1193 for(ch=0; ch<s->channels; ch++) {
1194 sub = &frame->subframes[ch];
1195
1196 /* subframe header */
1197 put_bits(&s->pb, 1, 0);
1198 put_bits(&s->pb, 6, sub->type_code);
1199 put_bits(&s->pb, 1, 0); /* no wasted bits */
1200
1201 /* subframe */
1202 if(sub->type == FLAC_SUBFRAME_CONSTANT) {
1203 output_subframe_constant(s, ch);
1204 } else if(sub->type == FLAC_SUBFRAME_VERBATIM) {
1205 output_subframe_verbatim(s, ch);
1206 } else if(sub->type == FLAC_SUBFRAME_FIXED) {
1207 output_subframe_fixed(s, ch);
1208 } else if(sub->type == FLAC_SUBFRAME_LPC) {
1209 output_subframe_lpc(s, ch);
1210 }
1211 }
1212 }
1213
1214 static void output_frame_footer(FlacEncodeContext *s)
1215 {
1216 int crc;
1217 flush_put_bits(&s->pb);
1218 crc = bswap_16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0,
1219 s->pb.buf, put_bits_count(&s->pb)>>3));
1220 put_bits(&s->pb, 16, crc);
1221 flush_put_bits(&s->pb);
1222 }
1223
1224 static void update_md5_sum(FlacEncodeContext *s, int16_t *samples)
1225 {
1226 #ifdef WORDS_BIGENDIAN
1227 int i;
1228 for(i = 0; i < s->frame.blocksize*s->channels; i++) {
1229 int16_t smp = le2me_16(samples[i]);
1230 av_md5_update(s->md5ctx, (uint8_t *)&smp, 2);
1231 }
1232 #else
1233 av_md5_update(s->md5ctx, (uint8_t *)samples, s->frame.blocksize*s->channels*2);
1234 #endif
1235 }
1236
1237 static int flac_encode_frame(AVCodecContext *avctx, uint8_t *frame,
1238 int buf_size, void *data)
1239 {
1240 int ch;
1241 FlacEncodeContext *s;
1242 int16_t *samples = data;
1243 int out_bytes;
1244 int reencoded=0;
1245
1246 s = avctx->priv_data;
1247
1248 if(buf_size < s->max_framesize*2) {
1249 av_log(avctx, AV_LOG_ERROR, "output buffer too small\n");
1250 return 0;
1251 }
1252
1253 /* when the last block is reached, update the header in extradata */
1254 if (!data) {
1255 s->max_framesize = s->max_encoded_framesize;
1256 av_md5_final(s->md5ctx, s->md5sum);
1257 write_streaminfo(s, avctx->extradata);
1258 return 0;
1259 }
1260
1261 init_frame(s);
1262
1263 copy_samples(s, samples);
1264
1265 channel_decorrelation(s);
1266
1267 for(ch=0; ch<s->channels; ch++) {
1268 encode_residual(s, ch);
1269 }
1270
1271 write_frame:
1272 init_put_bits(&s->pb, frame, buf_size);
1273 output_frame_header(s);
1274 output_subframes(s);
1275 output_frame_footer(s);
1276 out_bytes = put_bits_count(&s->pb) >> 3;
1277
1278 if(out_bytes > s->max_framesize) {
1279 if(reencoded) {
1280 /* still too large. must be an error. */
1281 av_log(avctx, AV_LOG_ERROR, "error encoding frame\n");
1282 return -1;
1283 }
1284
1285 /* frame too large. use verbatim mode */
1286 for(ch=0; ch<s->channels; ch++) {
1287 encode_residual_v(s, ch);
1288 }
1289 reencoded = 1;
1290 goto write_frame;
1291 }
1292
1293 s->frame_count++;
1294 s->sample_count += avctx->frame_size;
1295 update_md5_sum(s, samples);
1296 if (out_bytes > s->max_encoded_framesize)
1297 s->max_encoded_framesize = out_bytes;
1298 if (out_bytes < s->min_framesize)
1299 s->min_framesize = out_bytes;
1300
1301 return out_bytes;
1302 }
1303
1304 static av_cold int flac_encode_close(AVCodecContext *avctx)
1305 {
1306 if (avctx->priv_data) {
1307 FlacEncodeContext *s = avctx->priv_data;
1308 av_freep(&s->md5ctx);
1309 }
1310 av_freep(&avctx->extradata);
1311 avctx->extradata_size = 0;
1312 av_freep(&avctx->coded_frame);
1313 return 0;
1314 }
1315
1316 AVCodec flac_encoder = {
1317 "flac",
1318 CODEC_TYPE_AUDIO,
1319 CODEC_ID_FLAC,
1320 sizeof(FlacEncodeContext),
1321 flac_encode_init,
1322 flac_encode_frame,
1323 flac_encode_close,
1324 NULL,
1325 .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY,
1326 .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
1327 .long_name = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
1328 };
ffmpeg Lagarith lossless decoder