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 31#define FLAC_MAX_CH 8 32#define FLAC_MIN_BLOCKSIZE 16 33#define FLAC_MAX_BLOCKSIZE 65535 34 35#define FLAC_SUBFRAME_CONSTANT 0 36#define FLAC_SUBFRAME_VERBATIM 1 37#define FLAC_SUBFRAME_FIXED 8 38#define FLAC_SUBFRAME_LPC 32 39 40#define FLAC_CHMODE_NOT_STEREO 0 41#define FLAC_CHMODE_LEFT_RIGHT 1 42#define FLAC_CHMODE_LEFT_SIDE 8 43#define FLAC_CHMODE_RIGHT_SIDE 9 44#define FLAC_CHMODE_MID_SIDE 10 45 46#define FLAC_STREAMINFO_SIZE 34 47 48#define MAX_FIXED_ORDER 4 49#define MAX_PARTITION_ORDER 8 50#define MAX_PARTITIONS (1 << MAX_PARTITION_ORDER) 51#define MAX_LPC_PRECISION 15 52#define MAX_LPC_SHIFT 15 53#define MAX_RICE_PARAM 14 54 55typedef struct CompressionOptions { 56 int compression_level; 57 int block_time_ms; 58 int use_lpc; 59 int lpc_coeff_precision; 60 int min_prediction_order; 61 int max_prediction_order; 62 int prediction_order_method; 63 int min_partition_order; 64 int max_partition_order; 65} CompressionOptions; 66 67typedef struct RiceContext { 68 int porder; 69 int params[MAX_PARTITIONS]; 70} RiceContext; 71 72typedef struct FlacSubframe { 73 int type; 74 int type_code; 75 int obits; 76 int order; 77 int32_t coefs[MAX_LPC_ORDER]; 78 int shift; 79 RiceContext rc; 80 int32_t samples[FLAC_MAX_BLOCKSIZE]; 81 int32_t residual[FLAC_MAX_BLOCKSIZE+1]; 82} FlacSubframe; 83 84typedef struct FlacFrame { 85 FlacSubframe subframes[FLAC_MAX_CH]; 86 int blocksize; 87 int bs_code[2]; 88 uint8_t crc8; 89 int ch_mode; 90} FlacFrame; 91 92typedef struct FlacEncodeContext { 93 PutBitContext pb; 94 int channels; 95 int ch_code; 96 int samplerate; 97 int sr_code[2]; 98 int min_framesize; 99 int min_encoded_framesize; 100 int max_framesize; 101 int max_encoded_framesize; 102 uint32_t frame_count; 103 uint64_t sample_count; 104 uint8_t md5sum[16]; 105 FlacFrame frame; 106 CompressionOptions options; 107 AVCodecContext *avctx; 108 DSPContext dsp; 109 struct AVMD5 *md5ctx; 110} FlacEncodeContext; 111 112static const int flac_samplerates[16] = { 113 0, 0, 0, 0, 114 8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000, 115 0, 0, 0, 0 116}; 117 118static const int flac_blocksizes[16] = { 119 0, 120 192, 121 576, 1152, 2304, 4608, 122 0, 0, 123 256, 512, 1024, 2048, 4096, 8192, 16384, 32768 124}; 125 126/** 127 * Writes streaminfo metadata block to byte array 128 */ 129static void write_streaminfo(FlacEncodeContext *s, uint8_t *header) 130{ 131 PutBitContext pb; 132 133 memset(header, 0, FLAC_STREAMINFO_SIZE); 134 init_put_bits(&pb, header, FLAC_STREAMINFO_SIZE); 135 136 /* streaminfo metadata block */ 137 put_bits(&pb, 16, s->avctx->frame_size); 138 put_bits(&pb, 16, s->avctx->frame_size); 139 put_bits(&pb, 24, s->min_framesize); 140 put_bits(&pb, 24, s->max_framesize); 141 put_bits(&pb, 20, s->samplerate); 142 put_bits(&pb, 3, s->channels-1); 143 put_bits(&pb, 5, 15); /* bits per sample - 1 */ 144 /* write 36-bit sample count in 2 put_bits() calls */ 145 put_bits(&pb, 24, (s->sample_count & 0xFFFFFF000LL) >> 12); 146 put_bits(&pb, 12, s->sample_count & 0x000000FFFLL); 147 flush_put_bits(&pb); 148 memcpy(&header[18], s->md5sum, 16); 149} 150 151/** 152 * Sets blocksize based on samplerate 153 * Chooses the closest predefined blocksize >= BLOCK_TIME_MS milliseconds 154 */ 155static int select_blocksize(int samplerate, int block_time_ms) 156{ 157 int i; 158 int target; 159 int blocksize; 160 161 assert(samplerate > 0); 162 blocksize = flac_blocksizes[1]; 163 target = (samplerate * block_time_ms) / 1000; 164 for(i=0; i<16; i++) { 165 if(target >= flac_blocksizes[i] && flac_blocksizes[i] > blocksize) { 166 blocksize = flac_blocksizes[i]; 167 } 168 } 169 return blocksize; 170} 171 172static av_cold int flac_encode_init(AVCodecContext *avctx) 173{ 174 int freq = avctx->sample_rate; 175 int channels = avctx->channels; 176 FlacEncodeContext *s = avctx->priv_data; 177 int i, level; 178 uint8_t *streaminfo; 179 180 s->avctx = avctx; 181 182 dsputil_init(&s->dsp, avctx); 183 184 if(avctx->sample_fmt != SAMPLE_FMT_S16) { 185 return -1; 186 } 187 188 if(channels < 1 || channels > FLAC_MAX_CH) { 189 return -1; 190 } 191 s->channels = channels; 192 s->ch_code = s->channels-1; 193 194 /* find samplerate in table */ 195 if(freq < 1) 196 return -1; 197 for(i=4; i<12; i++) { 198 if(freq == flac_samplerates[i]) { 199 s->samplerate = flac_samplerates[i]; 200 s->sr_code[0] = i; 201 s->sr_code[1] = 0; 202 break; 203 } 204 } 205 /* if not in table, samplerate is non-standard */ 206 if(i == 12) { 207 if(freq % 1000 == 0 && freq < 255000) { 208 s->sr_code[0] = 12; 209 s->sr_code[1] = freq / 1000; 210 } else if(freq % 10 == 0 && freq < 655350) { 211 s->sr_code[0] = 14; 212 s->sr_code[1] = freq / 10; 213 } else if(freq < 65535) { 214 s->sr_code[0] = 13; 215 s->sr_code[1] = freq; 216 } else { 217 return -1; 218 } 219 s->samplerate = freq; 220 } 221 222 /* set compression option defaults based on avctx->compression_level */ 223 if(avctx->compression_level < 0) { 224 s->options.compression_level = 5; 225 } else { 226 s->options.compression_level = avctx->compression_level; 227 } 228 av_log(avctx, AV_LOG_DEBUG, " compression: %d\n", s->options.compression_level); 229 230 level= s->options.compression_level; 231 if(level > 12) { 232 av_log(avctx, AV_LOG_ERROR, "invalid compression level: %d\n", 233 s->options.compression_level); 234 return -1; 235 } 236 237 s->options.block_time_ms = ((int[]){ 27, 27, 27,105,105,105,105,105,105,105,105,105,105})[level]; 238 s->options.use_lpc = ((int[]){ 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level]; 239 s->options.min_prediction_order= ((int[]){ 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})[level]; 240 s->options.max_prediction_order= ((int[]){ 3, 4, 4, 6, 8, 8, 8, 8, 12, 12, 12, 32, 32})[level]; 241 s->options.prediction_order_method = ((int[]){ ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST, 242 ORDER_METHOD_EST, ORDER_METHOD_EST, ORDER_METHOD_EST, 243 ORDER_METHOD_4LEVEL, ORDER_METHOD_LOG, ORDER_METHOD_4LEVEL, 244 ORDER_METHOD_LOG, ORDER_METHOD_SEARCH, ORDER_METHOD_LOG, 245 ORDER_METHOD_SEARCH})[level]; 246 s->options.min_partition_order = ((int[]){ 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})[level]; 247 s->options.max_partition_order = ((int[]){ 2, 2, 3, 3, 3, 8, 8, 8, 8, 8, 8, 8, 8})[level]; 248 249 /* set compression option overrides from AVCodecContext */ 250 if(avctx->use_lpc >= 0) { 251 s->options.use_lpc = av_clip(avctx->use_lpc, 0, 11); 252 } 253 if(s->options.use_lpc == 1) 254 av_log(avctx, AV_LOG_DEBUG, " use lpc: Levinson-Durbin recursion with Welch window\n"); 255 else if(s->options.use_lpc > 1) 256 av_log(avctx, AV_LOG_DEBUG, " use lpc: Cholesky factorization\n"); 257 258 if(avctx->min_prediction_order >= 0) { 259 if(s->options.use_lpc) { 260 if(avctx->min_prediction_order < MIN_LPC_ORDER || 261 avctx->min_prediction_order > MAX_LPC_ORDER) { 262 av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n", 263 avctx->min_prediction_order); 264 return -1; 265 } 266 } else { 267 if(avctx->min_prediction_order > MAX_FIXED_ORDER) { 268 av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n", 269 avctx->min_prediction_order); 270 return -1; 271 } 272 } 273 s->options.min_prediction_order = avctx->min_prediction_order; 274 } 275 if(avctx->max_prediction_order >= 0) { 276 if(s->options.use_lpc) { 277 if(avctx->max_prediction_order < MIN_LPC_ORDER || 278 avctx->max_prediction_order > MAX_LPC_ORDER) { 279 av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n", 280 avctx->max_prediction_order); 281 return -1; 282 } 283 } else { 284 if(avctx->max_prediction_order > MAX_FIXED_ORDER) { 285 av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n", 286 avctx->max_prediction_order); 287 return -1; 288 } 289 } 290 s->options.max_prediction_order = avctx->max_prediction_order; 291 } 292 if(s->options.max_prediction_order < s->options.min_prediction_order) { 293 av_log(avctx, AV_LOG_ERROR, "invalid prediction orders: min=%d max=%d\n", 294 s->options.min_prediction_order, s->options.max_prediction_order); 295 return -1; 296 } 297 av_log(avctx, AV_LOG_DEBUG, " prediction order: %d, %d\n", 298 s->options.min_prediction_order, s->options.max_prediction_order); 299 300 if(avctx->prediction_order_method >= 0) { 301 if(avctx->prediction_order_method > ORDER_METHOD_LOG) { 302 av_log(avctx, AV_LOG_ERROR, "invalid prediction order method: %d\n", 303 avctx->prediction_order_method); 304 return -1; 305 } 306 s->options.prediction_order_method = avctx->prediction_order_method; 307 } 308 switch(s->options.prediction_order_method) { 309 case ORDER_METHOD_EST: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", 310 "estimate"); break; 311 case ORDER_METHOD_2LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", 312 "2-level"); break; 313 case ORDER_METHOD_4LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", 314 "4-level"); break; 315 case ORDER_METHOD_8LEVEL: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", 316 "8-level"); break; 317 case ORDER_METHOD_SEARCH: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", 318 "full search"); break; 319 case ORDER_METHOD_LOG: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", 320 "log search"); break; 321 } 322 323 if(avctx->min_partition_order >= 0) { 324 if(avctx->min_partition_order > MAX_PARTITION_ORDER) { 325 av_log(avctx, AV_LOG_ERROR, "invalid min partition order: %d\n", 326 avctx->min_partition_order); 327 return -1; 328 } 329 s->options.min_partition_order = avctx->min_partition_order; 330 } 331 if(avctx->max_partition_order >= 0) { 332 if(avctx->max_partition_order > MAX_PARTITION_ORDER) { 333 av_log(avctx, AV_LOG_ERROR, "invalid max partition order: %d\n", 334 avctx->max_partition_order); 335 return -1; 336 } 337 s->options.max_partition_order = avctx->max_partition_order; 338 } 339 if(s->options.max_partition_order < s->options.min_partition_order) { 340 av_log(avctx, AV_LOG_ERROR, "invalid partition orders: min=%d max=%d\n", 341 s->options.min_partition_order, s->options.max_partition_order); 342 return -1; 343 } 344 av_log(avctx, AV_LOG_DEBUG, " partition order: %d, %d\n", 345 s->options.min_partition_order, s->options.max_partition_order); 346 347 if(avctx->frame_size > 0) { 348 if(avctx->frame_size < FLAC_MIN_BLOCKSIZE || 349 avctx->frame_size > FLAC_MAX_BLOCKSIZE) { 350 av_log(avctx, AV_LOG_ERROR, "invalid block size: %d\n", 351 avctx->frame_size); 352 return -1; 353 } 354 } else { 355 s->avctx->frame_size = select_blocksize(s->samplerate, s->options.block_time_ms); 356 } 357 av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", s->avctx->frame_size); 358 359 /* set LPC precision */ 360 if(avctx->lpc_coeff_precision > 0) { 361 if(avctx->lpc_coeff_precision > MAX_LPC_PRECISION) { 362 av_log(avctx, AV_LOG_ERROR, "invalid lpc coeff precision: %d\n", 363 avctx->lpc_coeff_precision); 364 return -1; 365 } 366 s->options.lpc_coeff_precision = avctx->lpc_coeff_precision; 367 } else { 368 /* default LPC precision */ 369 s->options.lpc_coeff_precision = 15; 370 } 371 av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n", 372 s->options.lpc_coeff_precision); 373 374 /* set maximum encoded frame size in verbatim mode */ 375 if(s->channels == 2) { 376 s->max_framesize = 14 + ((s->avctx->frame_size * 33 + 7) >> 3); 377 } else { 378 s->max_framesize = 14 + (s->avctx->frame_size * s->channels * 2); 379 } 380 s->min_encoded_framesize = 0xFFFFFF; 381 382 /* initialize MD5 context */ 383 s->md5ctx = av_malloc(av_md5_size); 384 if(!s->md5ctx) 385 return AVERROR_NOMEM; 386 av_md5_init(s->md5ctx); 387 388 streaminfo = av_malloc(FLAC_STREAMINFO_SIZE); 389 write_streaminfo(s, streaminfo); 390 avctx->extradata = streaminfo; 391 avctx->extradata_size = FLAC_STREAMINFO_SIZE; 392 393 s->frame_count = 0; 394 395 avctx->coded_frame = avcodec_alloc_frame(); 396 avctx->coded_frame->key_frame = 1; 397 398 return 0; 399} 400 401static void init_frame(FlacEncodeContext *s) 402{ 403 int i, ch; 404 FlacFrame *frame; 405 406 frame = &s->frame; 407 408 for(i=0; i<16; i++) { 409 if(s->avctx->frame_size == flac_blocksizes[i]) { 410 frame->blocksize = flac_blocksizes[i]; 411 frame->bs_code[0] = i; 412 frame->bs_code[1] = 0; 413 break; 414 } 415 } 416 if(i == 16) { 417 frame->blocksize = s->avctx->frame_size; 418 if(frame->blocksize <= 256) { 419 frame->bs_code[0] = 6; 420 frame->bs_code[1] = frame->blocksize-1; 421 } else { 422 frame->bs_code[0] = 7; 423 frame->bs_code[1] = frame->blocksize-1; 424 } 425 } 426 427 for(ch=0; ch<s->channels; ch++) { 428 frame->subframes[ch].obits = 16; 429 } 430} 431 432/** 433 * Copy channel-interleaved input samples into separate subframes 434 */ 435static void copy_samples(FlacEncodeContext *s, int16_t *samples) 436{ 437 int i, j, ch; 438 FlacFrame *frame; 439 440 frame = &s->frame; 441 for(i=0,j=0; i<frame->blocksize; i++) { 442 for(ch=0; ch<s->channels; ch++,j++) { 443 frame->subframes[ch].samples[i] = samples[j]; 444 } 445 } 446} 447 448 449#define rice_encode_count(sum, n, k) (((n)*((k)+1))+((sum-(n>>1))>>(k))) 450 451/** 452 * Solve for d/dk(rice_encode_count) = n-((sum-(n>>1))>>(k+1)) = 0 453 */ 454static int find_optimal_param(uint32_t sum, int n) 455{ 456 int k; 457 uint32_t sum2; 458 459 if(sum <= n>>1) 460 return 0; 461 sum2 = sum-(n>>1); 462 k = av_log2(n<256 ? FASTDIV(sum2,n) : sum2/n); 463 return FFMIN(k, MAX_RICE_PARAM); 464} 465 466static uint32_t calc_optimal_rice_params(RiceContext *rc, int porder, 467 uint32_t *sums, int n, int pred_order) 468{ 469 int i; 470 int k, cnt, part; 471 uint32_t all_bits; 472 473 part = (1 << porder); 474 all_bits = 4 * part; 475 476 cnt = (n >> porder) - pred_order; 477 for(i=0; i<part; i++) { 478 k = find_optimal_param(sums[i], cnt); 479 rc->params[i] = k; 480 all_bits += rice_encode_count(sums[i], cnt, k); 481 cnt = n >> porder; 482 } 483 484 rc->porder = porder; 485 486 return all_bits; 487} 488 489static void calc_sums(int pmin, int pmax, uint32_t *data, int n, int pred_order, 490 uint32_t sums[][MAX_PARTITIONS]) 491{ 492 int i, j; 493 int parts; 494 uint32_t *res, *res_end; 495 496 /* sums for highest level */ 497 parts = (1 << pmax); 498 res = &data[pred_order]; 499 res_end = &data[n >> pmax]; 500 for(i=0; i<parts; i++) { 501 uint32_t sum = 0; 502 while(res < res_end){ 503 sum += *(res++); 504 } 505 sums[pmax][i] = sum; 506 res_end+= n >> pmax; 507 } 508 /* sums for lower levels */ 509 for(i=pmax-1; i>=pmin; i--) { 510 parts = (1 << i); 511 for(j=0; j<parts; j++) { 512 sums[i][j] = sums[i+1][2*j] + sums[i+1][2*j+1]; 513 } 514 } 515} 516 517static uint32_t calc_rice_params(RiceContext *rc, int pmin, int pmax, 518 int32_t *data, int n, int pred_order) 519{ 520 int i; 521 uint32_t bits[MAX_PARTITION_ORDER+1]; 522 int opt_porder; 523 RiceContext tmp_rc; 524 uint32_t *udata; 525 uint32_t sums[MAX_PARTITION_ORDER+1][MAX_PARTITIONS]; 526 527 assert(pmin >= 0 && pmin <= MAX_PARTITION_ORDER); 528 assert(pmax >= 0 && pmax <= MAX_PARTITION_ORDER); 529 assert(pmin <= pmax); 530 531 udata = av_malloc(n * sizeof(uint32_t)); 532 for(i=0; i<n; i++) { 533 udata[i] = (2*data[i]) ^ (data[i]>>31); 534 } 535 536 calc_sums(pmin, pmax, udata, n, pred_order, sums); 537 538 opt_porder = pmin; 539 bits[pmin] = UINT32_MAX; 540 for(i=pmin; i<=pmax; i++) { 541 bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums[i], n, pred_order); 542 if(bits[i] <= bits[opt_porder]) { 543 opt_porder = i; 544 *rc= tmp_rc; 545 } 546 } 547 548 av_freep(&udata); 549 return bits[opt_porder]; 550} 551 552static int get_max_p_order(int max_porder, int n, int order) 553{ 554 int porder = FFMIN(max_porder, av_log2(n^(n-1))); 555 if(order > 0) 556 porder = FFMIN(porder, av_log2(n/order)); 557 return porder; 558} 559 560static uint32_t calc_rice_params_fixed(RiceContext *rc, int pmin, int pmax, 561 int32_t *data, int n, int pred_order, 562 int bps) 563{ 564 uint32_t bits; 565 pmin = get_max_p_order(pmin, n, pred_order); 566 pmax = get_max_p_order(pmax, n, pred_order); 567 bits = pred_order*bps + 6; 568 bits += calc_rice_params(rc, pmin, pmax, data, n, pred_order); 569 return bits; 570} 571 572static uint32_t calc_rice_params_lpc(RiceContext *rc, int pmin, int pmax, 573 int32_t *data, int n, int pred_order, 574 int bps, int precision) 575{ 576 uint32_t bits; 577 pmin = get_max_p_order(pmin, n, pred_order); 578 pmax = get_max_p_order(pmax, n, pred_order); 579 bits = pred_order*bps + 4 + 5 + pred_order*precision + 6; 580 bits += calc_rice_params(rc, pmin, pmax, data, n, pred_order); 581 return bits; 582} 583 584/** 585 * Apply Welch window function to audio block 586 */ 587static void apply_welch_window(const int32_t *data, int len, double *w_data) 588{ 589 int i, n2; 590 double w; 591 double c; 592 593 assert(!(len&1)); //the optimization in r11881 does not support odd len 594 //if someone wants odd len extend the change in r11881 595 596 n2 = (len >> 1); 597 c = 2.0 / (len - 1.0); 598 599 w_data+=n2; 600 data+=n2; 601 for(i=0; i<n2; i++) { 602 w = c - n2 + i; 603 w = 1.0 - (w * w); 604 w_data[-i-1] = data[-i-1] * w; 605 w_data[+i ] = data[+i ] * w; 606 } 607} 608 609/** 610 * Calculates autocorrelation data from audio samples 611 * A Welch window function is applied before calculation. 612 */ 613void ff_flac_compute_autocorr(const int32_t *data, int len, int lag, 614 double *autoc) 615{ 616 int i, j; 617 double tmp[len + lag + 1]; 618 double *data1= tmp + lag; 619 620 apply_welch_window(data, len, data1); 621 622 for(j=0; j<lag; j++) 623 data1[j-lag]= 0.0; 624 data1[len] = 0.0; 625 626 for(j=0; j<lag; j+=2){ 627 double sum0 = 1.0, sum1 = 1.0; 628 for(i=0; i<len; i++){ 629 sum0 += data1[i] * data1[i-j]; 630 sum1 += data1[i] * data1[i-j-1]; 631 } 632 autoc[j ] = sum0; 633 autoc[j+1] = sum1; 634 } 635 636 if(j==lag){ 637 double sum = 1.0; 638 for(i=0; i<len; i+=2){ 639 sum += data1[i ] * data1[i-j ] 640 + data1[i+1] * data1[i-j+1]; 641 } 642 autoc[j] = sum; 643 } 644} 645 646 647static void encode_residual_verbatim(int32_t *res, int32_t *smp, int n) 648{ 649 assert(n > 0); 650 memcpy(res, smp, n * sizeof(int32_t)); 651} 652 653static void encode_residual_fixed(int32_t *res, const int32_t *smp, int n, 654 int order) 655{ 656 int i; 657 658 for(i=0; i<order; i++) { 659 res[i] = smp[i]; 660 } 661 662 if(order==0){ 663 for(i=order; i<n; i++) 664 res[i]= smp[i]; 665 }else if(order==1){ 666 for(i=order; i<n; i++) 667 res[i]= smp[i] - smp[i-1]; 668 }else if(order==2){ 669 int a = smp[order-1] - smp[order-2]; 670 for(i=order; i<n; i+=2) { 671 int b = smp[i] - smp[i-1]; 672 res[i]= b - a; 673 a = smp[i+1] - smp[i]; 674 res[i+1]= a - b; 675 } 676 }else if(order==3){ 677 int a = smp[order-1] - smp[order-2]; 678 int c = smp[order-1] - 2*smp[order-2] + smp[order-3]; 679 for(i=order; i<n; i+=2) { 680 int b = smp[i] - smp[i-1]; 681 int d = b - a; 682 res[i]= d - c; 683 a = smp[i+1] - smp[i]; 684 c = a - b; 685 res[i+1]= c - d; 686 } 687 }else{ 688 int a = smp[order-1] - smp[order-2]; 689 int c = smp[order-1] - 2*smp[order-2] + smp[order-3]; 690 int e = smp[order-1] - 3*smp[order-2] + 3*smp[order-3] - smp[order-4]; 691 for(i=order; i<n; i+=2) { 692 int b = smp[i] - smp[i-1]; 693 int d = b - a; 694 int f = d - c; 695 res[i]= f - e; 696 a = smp[i+1] - smp[i]; 697 c = a - b; 698 e = c - d; 699 res[i+1]= e - f; 700 } 701 } 702} 703 704#define LPC1(x) {\ 705 int c = coefs[(x)-1];\ 706 p0 += c*s;\ 707 s = smp[i-(x)+1];\ 708 p1 += c*s;\ 709} 710 711static av_always_inline void encode_residual_lpc_unrolled( 712 int32_t *res, const int32_t *smp, int n, 713 int order, const int32_t *coefs, int shift, int big) 714{ 715 int i; 716 for(i=order; i<n; i+=2) { 717 int s = smp[i-order]; 718 int p0 = 0, p1 = 0; 719 if(big) { 720 switch(order) { 721 case 32: LPC1(32) 722 case 31: LPC1(31) 723 case 30: LPC1(30) 724 case 29: LPC1(29) 725 case 28: LPC1(28) 726 case 27: LPC1(27) 727 case 26: LPC1(26) 728 case 25: LPC1(25) 729 case 24: LPC1(24) 730 case 23: LPC1(23) 731 case 22: LPC1(22) 732 case 21: LPC1(21) 733 case 20: LPC1(20) 734 case 19: LPC1(19) 735 case 18: LPC1(18) 736 case 17: LPC1(17) 737 case 16: LPC1(16) 738 case 15: LPC1(15) 739 case 14: LPC1(14) 740 case 13: LPC1(13) 741 case 12: LPC1(12) 742 case 11: LPC1(11) 743 case 10: LPC1(10) 744 case 9: LPC1( 9) 745 LPC1( 8) 746 LPC1( 7) 747 LPC1( 6) 748 LPC1( 5) 749 LPC1( 4) 750 LPC1( 3) 751 LPC1( 2) 752 LPC1( 1) 753 } 754 } else { 755 switch(order) { 756 case 8: LPC1( 8) 757 case 7: LPC1( 7) 758 case 6: LPC1( 6) 759 case 5: LPC1( 5) 760 case 4: LPC1( 4) 761 case 3: LPC1( 3) 762 case 2: LPC1( 2) 763 case 1: LPC1( 1) 764 } 765 } 766 res[i ] = smp[i ] - (p0 >> shift); 767 res[i+1] = smp[i+1] - (p1 >> shift); 768 } 769} 770 771static void encode_residual_lpc(int32_t *res, const int32_t *smp, int n, 772 int order, const int32_t *coefs, int shift) 773{ 774 int i; 775 for(i=0; i<order; i++) { 776 res[i] = smp[i]; 777 } 778#if CONFIG_SMALL 779 for(i=order; i<n; i+=2) { 780 int j; 781 int s = smp[i]; 782 int p0 = 0, p1 = 0; 783 for(j=0; j<order; j++) { 784 int c = coefs[j]; 785 p1 += c*s; 786 s = smp[i-j-1]; 787 p0 += c*s; 788 } 789 res[i ] = smp[i ] - (p0 >> shift); 790 res[i+1] = smp[i+1] - (p1 >> shift); 791 } 792#else 793 switch(order) { 794 case 1: encode_residual_lpc_unrolled(res, smp, n, 1, coefs, shift, 0); break; 795 case 2: encode_residual_lpc_unrolled(res, smp, n, 2, coefs, shift, 0); break; 796 case 3: encode_residual_lpc_unrolled(res, smp, n, 3, coefs, shift, 0); break; 797 case 4: encode_residual_lpc_unrolled(res, smp, n, 4, coefs, shift, 0); break; 798 case 5: encode_residual_lpc_unrolled(res, smp, n, 5, coefs, shift, 0); break; 799 case 6: encode_residual_lpc_unrolled(res, smp, n, 6, coefs, shift, 0); break; 800 case 7: encode_residual_lpc_unrolled(res, smp, n, 7, coefs, shift, 0); break; 801 case 8: encode_residual_lpc_unrolled(res, smp, n, 8, coefs, shift, 0); break; 802 default: encode_residual_lpc_unrolled(res, smp, n, order, coefs, shift, 1); break; 803 } 804#endif 805} 806 807static int encode_residual(FlacEncodeContext *ctx, int ch) 808{ 809 int i, n; 810 int min_order, max_order, opt_order, precision, omethod; 811 int min_porder, max_porder; 812 FlacFrame *frame; 813 FlacSubframe *sub; 814 int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER]; 815 int shift[MAX_LPC_ORDER]; 816 int32_t *res, *smp; 817 818 frame = &ctx->frame; 819 sub = &frame->subframes[ch]; 820 res = sub->residual; 821 smp = sub->samples; 822 n = frame->blocksize; 823 824 /* CONSTANT */ 825 for(i=1; i<n; i++) { 826 if(smp[i] != smp[0]) break; 827 } 828 if(i == n) { 829 sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT; 830 res[0] = smp[0]; 831 return sub->obits; 832 } 833 834 /* VERBATIM */ 835 if(n < 5) { 836 sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM; 837 encode_residual_verbatim(res, smp, n); 838 return sub->obits * n; 839 } 840 841 min_order = ctx->options.min_prediction_order; 842 max_order = ctx->options.max_prediction_order; 843 min_porder = ctx->options.min_partition_order; 844 max_porder = ctx->options.max_partition_order; 845 precision = ctx->options.lpc_coeff_precision; 846 omethod = ctx->options.prediction_order_method; 847 848 /* FIXED */ 849 if(!ctx->options.use_lpc || max_order == 0 || (n <= max_order)) { 850 uint32_t bits[MAX_FIXED_ORDER+1]; 851 if(max_order > MAX_FIXED_ORDER) max_order = MAX_FIXED_ORDER; 852 opt_order = 0; 853 bits[0] = UINT32_MAX; 854 for(i=min_order; i<=max_order; i++) { 855 encode_residual_fixed(res, smp, n, i); 856 bits[i] = calc_rice_params_fixed(&sub->rc, min_porder, max_porder, res, 857 n, i, sub->obits); 858 if(bits[i] < bits[opt_order]) { 859 opt_order = i; 860 } 861 } 862 sub->order = opt_order; 863 sub->type = FLAC_SUBFRAME_FIXED; 864 sub->type_code = sub->type | sub->order; 865 if(sub->order != max_order) { 866 encode_residual_fixed(res, smp, n, sub->order); 867 return calc_rice_params_fixed(&sub->rc, min_porder, max_porder, res, n, 868 sub->order, sub->obits); 869 } 870 return bits[sub->order]; 871 } 872 873 /* LPC */ 874 opt_order = ff_lpc_calc_coefs(&ctx->dsp, smp, n, min_order, max_order, 875 precision, coefs, shift, ctx->options.use_lpc, 876 omethod, MAX_LPC_SHIFT, 0); 877 878 if(omethod == ORDER_METHOD_2LEVEL || 879 omethod == ORDER_METHOD_4LEVEL || 880 omethod == ORDER_METHOD_8LEVEL) { 881 int levels = 1 << omethod; 882 uint32_t bits[levels]; 883 int order; 884 int opt_index = levels-1; 885 opt_order = max_order-1; 886 bits[opt_index] = UINT32_MAX; 887 for(i=levels-1; i>=0; i--) { 888 order = min_order + (((max_order-min_order+1) * (i+1)) / levels)-1; 889 if(order < 0) order = 0; 890 encode_residual_lpc(res, smp, n, order+1, coefs[order], shift[order]); 891 bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder, 892 res, n, order+1, sub->obits, precision); 893 if(bits[i] < bits[opt_index]) { 894 opt_index = i; 895 opt_order = order; 896 } 897 } 898 opt_order++; 899 } else if(omethod == ORDER_METHOD_SEARCH) { 900 // brute-force optimal order search 901 uint32_t bits[MAX_LPC_ORDER]; 902 opt_order = 0; 903 bits[0] = UINT32_MAX; 904 for(i=min_order-1; i<max_order; i++) { 905 encode_residual_lpc(res, smp, n, i+1, coefs[i], shift[i]); 906 bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder, 907 res, n, i+1, sub->obits, precision); 908 if(bits[i] < bits[opt_order]) { 909 opt_order = i; 910 } 911 } 912 opt_order++; 913 } else if(omethod == ORDER_METHOD_LOG) { 914 uint32_t bits[MAX_LPC_ORDER]; 915 int step; 916 917 opt_order= min_order - 1 + (max_order-min_order)/3; 918 memset(bits, -1, sizeof(bits)); 919 920 for(step=16 ;step; step>>=1){ 921 int last= opt_order; 922 for(i=last-step; i<=last+step; i+= step){ 923 if(i<min_order-1 || i>=max_order || bits[i] < UINT32_MAX) 924 continue; 925 encode_residual_lpc(res, smp, n, i+1, coefs[i], shift[i]); 926 bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder, 927 res, n, i+1, sub->obits, precision); 928 if(bits[i] < bits[opt_order]) 929 opt_order= i; 930 } 931 } 932 opt_order++; 933 } 934 935 sub->order = opt_order; 936 sub->type = FLAC_SUBFRAME_LPC; 937 sub->type_code = sub->type | (sub->order-1); 938 sub->shift = shift[sub->order-1]; 939 for(i=0; i<sub->order; i++) { 940 sub->coefs[i] = coefs[sub->order-1][i]; 941 } 942 encode_residual_lpc(res, smp, n, sub->order, sub->coefs, sub->shift); 943 return calc_rice_params_lpc(&sub->rc, min_porder, max_porder, res, n, sub->order, 944 sub->obits, precision); 945} 946 947static int encode_residual_v(FlacEncodeContext *ctx, int ch) 948{ 949 int i, n; 950 FlacFrame *frame; 951 FlacSubframe *sub; 952 int32_t *res, *smp; 953 954 frame = &ctx->frame; 955 sub = &frame->subframes[ch]; 956 res = sub->residual; 957 smp = sub->samples; 958 n = frame->blocksize; 959 960 /* CONSTANT */ 961 for(i=1; i<n; i++) { 962 if(smp[i] != smp[0]) break; 963 } 964 if(i == n) { 965 sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT; 966 res[0] = smp[0]; 967 return sub->obits; 968 } 969 970 /* VERBATIM */ 971 sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM; 972 encode_residual_verbatim(res, smp, n); 973 return sub->obits * n; 974} 975 976static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n) 977{ 978 int i, best; 979 int32_t lt, rt; 980 uint64_t sum[4]; 981 uint64_t score[4]; 982 int k; 983 984 /* calculate sum of 2nd order residual for each channel */ 985 sum[0] = sum[1] = sum[2] = sum[3] = 0; 986 for(i=2; i<n; i++) { 987 lt = left_ch[i] - 2*left_ch[i-1] + left_ch[i-2]; 988 rt = right_ch[i] - 2*right_ch[i-1] + right_ch[i-2]; 989 sum[2] += FFABS((lt + rt) >> 1); 990 sum[3] += FFABS(lt - rt); 991 sum[0] += FFABS(lt); 992 sum[1] += FFABS(rt); 993 } 994 /* estimate bit counts */ 995 for(i=0; i<4; i++) { 996 k = find_optimal_param(2*sum[i], n); 997 sum[i] = rice_encode_count(2*sum[i], n, k); 998 } 999 1000 /* calculate score for each mode */ 1001 score[0] = sum[0] + sum[1]; 1002 score[1] = sum[0] + sum[3]; 1003 score[2] = sum[1] + sum[3]; 1004 score[3] = sum[2] + sum[3]; 1005 1006 /* return mode with lowest score */ 1007 best = 0; 1008 for(i=1; i<4; i++) { 1009 if(score[i] < score[best]) { 1010 best = i; 1011 } 1012 } 1013 if(best == 0) { 1014 return FLAC_CHMODE_LEFT_RIGHT; 1015 } else if(best == 1) { 1016 return FLAC_CHMODE_LEFT_SIDE; 1017 } else if(best == 2) { 1018 return FLAC_CHMODE_RIGHT_SIDE; 1019 } else { 1020 return FLAC_CHMODE_MID_SIDE; 1021 } 1022} 1023 1024/** 1025 * Perform stereo channel decorrelation 1026 */ 1027static void channel_decorrelation(FlacEncodeContext *ctx) 1028{ 1029 FlacFrame *frame; 1030 int32_t *left, *right; 1031 int i, n; 1032 1033 frame = &ctx->frame; 1034 n = frame->blocksize; 1035 left = frame->subframes[0].samples; 1036 right = frame->subframes[1].samples; 1037 1038 if(ctx->channels != 2) { 1039 frame->ch_mode = FLAC_CHMODE_NOT_STEREO; 1040 return; 1041 } 1042 1043 frame->ch_mode = estimate_stereo_mode(left, right, n); 1044 1045 /* perform decorrelation and adjust bits-per-sample */ 1046 if(frame->ch_mode == FLAC_CHMODE_LEFT_RIGHT) { 1047 return; 1048 } 1049 if(frame->ch_mode == FLAC_CHMODE_MID_SIDE) { 1050 int32_t tmp; 1051 for(i=0; i<n; i++) { 1052 tmp = left[i]; 1053 left[i] = (tmp + right[i]) >> 1; 1054 right[i] = tmp - right[i]; 1055 } 1056 frame->subframes[1].obits++; 1057 } else if(frame->ch_mode == FLAC_CHMODE_LEFT_SIDE) { 1058 for(i=0; i<n; i++) { 1059 right[i] = left[i] - right[i]; 1060 } 1061 frame->subframes[1].obits++; 1062 } else { 1063 for(i=0; i<n; i++) { 1064 left[i] -= right[i]; 1065 } 1066 frame->subframes[0].obits++; 1067 } 1068} 1069 1070static void write_utf8(PutBitContext *pb, uint32_t val) 1071{ 1072 uint8_t tmp; 1073 PUT_UTF8(val, tmp, put_bits(pb, 8, tmp);) 1074} 1075 1076static void output_frame_header(FlacEncodeContext *s) 1077{ 1078 FlacFrame *frame; 1079 int crc; 1080 1081 frame = &s->frame; 1082 1083 put_bits(&s->pb, 16, 0xFFF8); 1084 put_bits(&s->pb, 4, frame->bs_code[0]); 1085 put_bits(&s->pb, 4, s->sr_code[0]); 1086 if(frame->ch_mode == FLAC_CHMODE_NOT_STEREO) { 1087 put_bits(&s->pb, 4, s->ch_code); 1088 } else { 1089 put_bits(&s->pb, 4, frame->ch_mode); 1090 } 1091 put_bits(&s->pb, 3, 4); /* bits-per-sample code */ 1092 put_bits(&s->pb, 1, 0); 1093 write_utf8(&s->pb, s->frame_count); 1094 if(frame->bs_code[0] == 6) { 1095 put_bits(&s->pb, 8, frame->bs_code[1]); 1096 } else if(frame->bs_code[0] == 7) { 1097 put_bits(&s->pb, 16, frame->bs_code[1]); 1098 } 1099 if(s->sr_code[0] == 12) { 1100 put_bits(&s->pb, 8, s->sr_code[1]); 1101 } else if(s->sr_code[0] > 12) { 1102 put_bits(&s->pb, 16, s->sr_code[1]); 1103 } 1104 flush_put_bits(&s->pb); 1105 crc = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, 1106 s->pb.buf, put_bits_count(&s->pb)>>3); 1107 put_bits(&s->pb, 8, crc); 1108} 1109 1110static void output_subframe_constant(FlacEncodeContext *s, int ch) 1111{ 1112 FlacSubframe *sub; 1113 int32_t res; 1114 1115 sub = &s->frame.subframes[ch]; 1116 res = sub->residual[0]; 1117 put_sbits(&s->pb, sub->obits, res); 1118} 1119 1120static void output_subframe_verbatim(FlacEncodeContext *s, int ch) 1121{ 1122 int i; 1123 FlacFrame *frame; 1124 FlacSubframe *sub; 1125 int32_t res; 1126 1127 frame = &s->frame; 1128 sub = &frame->subframes[ch]; 1129 1130 for(i=0; i<frame->blocksize; i++) { 1131 res = sub->residual[i]; 1132 put_sbits(&s->pb, sub->obits, res); 1133 } 1134} 1135 1136static void output_residual(FlacEncodeContext *ctx, int ch) 1137{ 1138 int i, j, p, n, parts; 1139 int k, porder, psize, res_cnt; 1140 FlacFrame *frame; 1141 FlacSubframe *sub; 1142 int32_t *res; 1143 1144 frame = &ctx->frame; 1145 sub = &frame->subframes[ch]; 1146 res = sub->residual; 1147 n = frame->blocksize; 1148 1149 /* rice-encoded block */ 1150 put_bits(&ctx->pb, 2, 0); 1151 1152 /* partition order */ 1153 porder = sub->rc.porder; 1154 psize = n >> porder; 1155 parts = (1 << porder); 1156 put_bits(&ctx->pb, 4, porder); 1157 res_cnt = psize - sub->order; 1158 1159 /* residual */ 1160 j = sub->order; 1161 for(p=0; p<parts; p++) { 1162 k = sub->rc.params[p]; 1163 put_bits(&ctx->pb, 4, k); 1164 if(p == 1) res_cnt = psize; 1165 for(i=0; i<res_cnt && j<n; i++, j++) { 1166 set_sr_golomb_flac(&ctx->pb, res[j], k, INT32_MAX, 0); 1167 } 1168 } 1169} 1170 1171static void output_subframe_fixed(FlacEncodeContext *ctx, int ch) 1172{ 1173 int i; 1174 FlacFrame *frame; 1175 FlacSubframe *sub; 1176 1177 frame = &ctx->frame; 1178 sub = &frame->subframes[ch]; 1179 1180 /* warm-up samples */ 1181 for(i=0; i<sub->order; i++) { 1182 put_sbits(&ctx->pb, sub->obits, sub->residual[i]); 1183 } 1184 1185 /* residual */ 1186 output_residual(ctx, ch); 1187} 1188 1189static void output_subframe_lpc(FlacEncodeContext *ctx, int ch) 1190{ 1191 int i, cbits; 1192 FlacFrame *frame; 1193 FlacSubframe *sub; 1194 1195 frame = &ctx->frame; 1196 sub = &frame->subframes[ch]; 1197 1198 /* warm-up samples */ 1199 for(i=0; i<sub->order; i++) { 1200 put_sbits(&ctx->pb, sub->obits, sub->residual[i]); 1201 } 1202 1203 /* LPC coefficients */ 1204 cbits = ctx->options.lpc_coeff_precision; 1205 put_bits(&ctx->pb, 4, cbits-1); 1206 put_sbits(&ctx->pb, 5, sub->shift); 1207 for(i=0; i<sub->order; i++) { 1208 put_sbits(&ctx->pb, cbits, sub->coefs[i]); 1209 } 1210 1211 /* residual */ 1212 output_residual(ctx, ch); 1213} 1214 1215static void output_subframes(FlacEncodeContext *s) 1216{ 1217 FlacFrame *frame; 1218 FlacSubframe *sub; 1219 int ch; 1220 1221 frame = &s->frame; 1222 1223 for(ch=0; ch<s->channels; ch++) { 1224 sub = &frame->subframes[ch]; 1225 1226 /* subframe header */ 1227 put_bits(&s->pb, 1, 0); 1228 put_bits(&s->pb, 6, sub->type_code); 1229 put_bits(&s->pb, 1, 0); /* no wasted bits */ 1230 1231 /* subframe */ 1232 if(sub->type == FLAC_SUBFRAME_CONSTANT) { 1233 output_subframe_constant(s, ch); 1234 } else if(sub->type == FLAC_SUBFRAME_VERBATIM) { 1235 output_subframe_verbatim(s, ch); 1236 } else if(sub->type == FLAC_SUBFRAME_FIXED) { 1237 output_subframe_fixed(s, ch); 1238 } else if(sub->type == FLAC_SUBFRAME_LPC) { 1239 output_subframe_lpc(s, ch); 1240 } 1241 } 1242} 1243 1244static void output_frame_footer(FlacEncodeContext *s) 1245{ 1246 int crc; 1247 flush_put_bits(&s->pb); 1248 crc = bswap_16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, 1249 s->pb.buf, put_bits_count(&s->pb)>>3)); 1250 put_bits(&s->pb, 16, crc); 1251 flush_put_bits(&s->pb); 1252} 1253 1254static void update_md5_sum(FlacEncodeContext *s, int16_t *samples) 1255{ 1256#ifdef WORDS_BIGENDIAN 1257 int i; 1258 for(i = 0; i < s->frame.blocksize*s->channels; i++) { 1259 int16_t smp = le2me_16(samples[i]); 1260 av_md5_update(s->md5ctx, (uint8_t *)&smp, 2); 1261 } 1262#else 1263 av_md5_update(s->md5ctx, (uint8_t *)samples, s->frame.blocksize*s->channels*2); 1264#endif 1265} 1266 1267static int flac_encode_frame(AVCodecContext *avctx, uint8_t *frame, 1268 int buf_size, void *data) 1269{ 1270 int ch; 1271 FlacEncodeContext *s; 1272 int16_t *samples = data; 1273 int out_bytes; 1274 int reencoded=0; 1275 1276 s = avctx->priv_data; 1277 1278 if(buf_size < s->max_framesize*2) { 1279 av_log(avctx, AV_LOG_ERROR, "output buffer too small\n"); 1280 return 0; 1281 } 1282 1283 /* when the last block is reached, update the header in extradata */ 1284 if (!data) { 1285 s->min_framesize = s->min_encoded_framesize; 1286 s->max_framesize = s->max_encoded_framesize; 1287 av_md5_final(s->md5ctx, s->md5sum); 1288 write_streaminfo(s, avctx->extradata); 1289 return 0; 1290 } 1291 1292 init_frame(s); 1293 1294 copy_samples(s, samples); 1295 1296 channel_decorrelation(s); 1297 1298 for(ch=0; ch<s->channels; ch++) { 1299 encode_residual(s, ch); 1300 } 1301 1302write_frame: 1303 init_put_bits(&s->pb, frame, buf_size); 1304 output_frame_header(s); 1305 output_subframes(s); 1306 output_frame_footer(s); 1307 out_bytes = put_bits_count(&s->pb) >> 3; 1308 1309 if(out_bytes > s->max_framesize) { 1310 if(reencoded) { 1311 /* still too large. must be an error. */ 1312 av_log(avctx, AV_LOG_ERROR, "error encoding frame\n"); 1313 return -1; 1314 } 1315 1316 /* frame too large. use verbatim mode */ 1317 for(ch=0; ch<s->channels; ch++) { 1318 encode_residual_v(s, ch); 1319 } 1320 reencoded = 1; 1321 goto write_frame; 1322 } 1323 1324 s->frame_count++; 1325 s->sample_count += avctx->frame_size; 1326 update_md5_sum(s, samples); 1327 if (out_bytes > s->max_encoded_framesize) 1328 s->max_encoded_framesize = out_bytes; 1329 if (out_bytes < s->min_encoded_framesize) 1330 s->min_encoded_framesize = out_bytes; 1331 1332 return out_bytes; 1333} 1334 1335static av_cold int flac_encode_close(AVCodecContext *avctx) 1336{ 1337 if (avctx->priv_data) { 1338 FlacEncodeContext *s = avctx->priv_data; 1339 av_freep(&s->md5ctx); 1340 } 1341 av_freep(&avctx->extradata); 1342 avctx->extradata_size = 0; 1343 av_freep(&avctx->coded_frame); 1344 return 0; 1345} 1346 1347AVCodec flac_encoder = { 1348 "flac", 1349 CODEC_TYPE_AUDIO, 1350 CODEC_ID_FLAC, 1351 sizeof(FlacEncodeContext), 1352 flac_encode_init, 1353 flac_encode_frame, 1354 flac_encode_close, 1355 NULL, 1356 .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY, 1357 .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE}, 1358 .long_name = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"), 1359}; 1360