1/* grabbag - Convenience lib for various routines common to several tools 2 * Copyright (C) 2002,2003,2004,2005,2006,2007 Josh Coalson 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Lesser General Public 6 * License as published by the Free Software Foundation; either 7 * version 2.1 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Lesser General Public License for more details. 13 * 14 * You should have received a copy of the GNU Lesser General Public 15 * License along with this library; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 19#if HAVE_CONFIG_H 20# include <config.h> 21#endif 22 23#include "share/grabbag.h" 24#include "share/replaygain_analysis.h" 25#include "FLAC/assert.h" 26#include "FLAC/metadata.h" 27#include "FLAC/stream_decoder.h" 28#include <locale.h> 29#include <math.h> 30#include <stdio.h> 31#include <stdlib.h> 32#include <string.h> 33#if defined _MSC_VER || defined __MINGW32__ 34#include <io.h> /* for chmod() */ 35#endif 36#include <sys/stat.h> /* for stat(), maybe chmod() */ 37 38#ifdef local_min 39#undef local_min 40#endif 41#define local_min(a,b) ((a)<(b)?(a):(b)) 42 43#ifdef local_max 44#undef local_max 45#endif 46#define local_max(a,b) ((a)>(b)?(a):(b)) 47 48static const char *reference_format_ = "%s=%2.1f dB"; 49static const char *gain_format_ = "%s=%+2.2f dB"; 50static const char *peak_format_ = "%s=%1.8f"; 51 52static double album_peak_, title_peak_; 53 54const unsigned GRABBAG__REPLAYGAIN_MAX_TAG_SPACE_REQUIRED = 190; 55/* 56 FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN/8 + 29 + 1 + 8 + 57 FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN/8 + 21 + 1 + 10 + 58 FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN/8 + 21 + 1 + 12 + 59 FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN/8 + 21 + 1 + 10 + 60 FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN/8 + 21 + 1 + 12 61*/ 62 63const FLAC__byte * const GRABBAG__REPLAYGAIN_TAG_REFERENCE_LOUDNESS = (const FLAC__byte * const)"REPLAYGAIN_REFERENCE_LOUDNESS"; 64const FLAC__byte * const GRABBAG__REPLAYGAIN_TAG_TITLE_GAIN = (const FLAC__byte * const)"REPLAYGAIN_TRACK_GAIN"; 65const FLAC__byte * const GRABBAG__REPLAYGAIN_TAG_TITLE_PEAK = (const FLAC__byte * const)"REPLAYGAIN_TRACK_PEAK"; 66const FLAC__byte * const GRABBAG__REPLAYGAIN_TAG_ALBUM_GAIN = (const FLAC__byte * const)"REPLAYGAIN_ALBUM_GAIN"; 67const FLAC__byte * const GRABBAG__REPLAYGAIN_TAG_ALBUM_PEAK = (const FLAC__byte * const)"REPLAYGAIN_ALBUM_PEAK"; 68 69 70static FLAC__bool get_file_stats_(const char *filename, struct stat *stats) 71{ 72 FLAC__ASSERT(0 != filename); 73 FLAC__ASSERT(0 != stats); 74 return (0 == stat(filename, stats)); 75} 76 77static void set_file_stats_(const char *filename, struct stat *stats) 78{ 79 FLAC__ASSERT(0 != filename); 80 FLAC__ASSERT(0 != stats); 81 82 (void)chmod(filename, stats->st_mode); 83} 84 85static FLAC__bool append_tag_(FLAC__StreamMetadata *block, const char *format, const FLAC__byte *name, float value) 86{ 87 char buffer[256]; 88 char *saved_locale; 89 FLAC__StreamMetadata_VorbisComment_Entry entry; 90 91 FLAC__ASSERT(0 != block); 92 FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT); 93 FLAC__ASSERT(0 != format); 94 FLAC__ASSERT(0 != name); 95 96 buffer[sizeof(buffer)-1] = '\0'; 97 /* 98 * We need to save the old locale and switch to "C" because the locale 99 * influences the formatting of %f and we want it a certain way. 100 */ 101 saved_locale = strdup(setlocale(LC_ALL, 0)); 102 if (0 == saved_locale) 103 return false; 104 setlocale(LC_ALL, "C"); 105#if defined _MSC_VER || defined __MINGW32__ 106 _snprintf(buffer, sizeof(buffer)-1, format, name, value); 107#else 108 snprintf(buffer, sizeof(buffer)-1, format, name, value); 109#endif 110 setlocale(LC_ALL, saved_locale); 111 free(saved_locale); 112 113 entry.entry = (FLAC__byte *)buffer; 114 entry.length = strlen(buffer); 115 116 return FLAC__metadata_object_vorbiscomment_append_comment(block, entry, /*copy=*/true); 117} 118 119FLAC__bool grabbag__replaygain_is_valid_sample_frequency(unsigned sample_frequency) 120{ 121 static const unsigned valid_sample_rates[] = { 122 8000, 123 11025, 124 12000, 125 16000, 126 22050, 127 24000, 128 32000, 129 44100, 130 48000 131 }; 132 static const unsigned n_valid_sample_rates = sizeof(valid_sample_rates) / sizeof(valid_sample_rates[0]); 133 134 unsigned i; 135 136 for(i = 0; i < n_valid_sample_rates; i++) 137 if(sample_frequency == valid_sample_rates[i]) 138 return true; 139 return false; 140} 141 142FLAC__bool grabbag__replaygain_init(unsigned sample_frequency) 143{ 144 title_peak_ = album_peak_ = 0.0; 145 return InitGainAnalysis((long)sample_frequency) == INIT_GAIN_ANALYSIS_OK; 146} 147 148FLAC__bool grabbag__replaygain_analyze(const FLAC__int32 * const input[], FLAC__bool is_stereo, unsigned bps, unsigned samples) 149{ 150 /* using a small buffer improves data locality; we'd like it to fit easily in the dcache */ 151 static Float_t lbuffer[2048], rbuffer[2048]; 152 static const unsigned nbuffer = sizeof(lbuffer) / sizeof(lbuffer[0]); 153 FLAC__int32 block_peak = 0, s; 154 unsigned i, j; 155 156 FLAC__ASSERT(bps >= 4 && bps <= FLAC__REFERENCE_CODEC_MAX_BITS_PER_SAMPLE); 157 FLAC__ASSERT(FLAC__MIN_BITS_PER_SAMPLE == 4); 158 /* 159 * We use abs() on a FLAC__int32 which is undefined for the most negative value. 160 * If the reference codec ever handles 32bps we will have to write a special 161 * case here. 162 */ 163 FLAC__ASSERT(FLAC__REFERENCE_CODEC_MAX_BITS_PER_SAMPLE < 32); 164 165 if(bps == 16) { 166 if(is_stereo) { 167 j = 0; 168 while(samples > 0) { 169 const unsigned n = local_min(samples, nbuffer); 170 for(i = 0; i < n; i++, j++) { 171 s = input[0][j]; 172 lbuffer[i] = (Float_t)s; 173 s = abs(s); 174 block_peak = local_max(block_peak, s); 175 176 s = input[1][j]; 177 rbuffer[i] = (Float_t)s; 178 s = abs(s); 179 block_peak = local_max(block_peak, s); 180 } 181 samples -= n; 182 if(AnalyzeSamples(lbuffer, rbuffer, n, 2) != GAIN_ANALYSIS_OK) 183 return false; 184 } 185 } 186 else { 187 j = 0; 188 while(samples > 0) { 189 const unsigned n = local_min(samples, nbuffer); 190 for(i = 0; i < n; i++, j++) { 191 s = input[0][j]; 192 lbuffer[i] = (Float_t)s; 193 s = abs(s); 194 block_peak = local_max(block_peak, s); 195 } 196 samples -= n; 197 if(AnalyzeSamples(lbuffer, 0, n, 1) != GAIN_ANALYSIS_OK) 198 return false; 199 } 200 } 201 } 202 else { /* bps must be < 32 according to above assertion */ 203 const double scale = ( 204 (bps > 16)? 205 (double)1. / (double)(1u << (bps - 16)) : 206 (double)(1u << (16 - bps)) 207 ); 208 209 if(is_stereo) { 210 j = 0; 211 while(samples > 0) { 212 const unsigned n = local_min(samples, nbuffer); 213 for(i = 0; i < n; i++, j++) { 214 s = input[0][j]; 215 lbuffer[i] = (Float_t)(scale * (double)s); 216 s = abs(s); 217 block_peak = local_max(block_peak, s); 218 219 s = input[1][j]; 220 rbuffer[i] = (Float_t)(scale * (double)s); 221 s = abs(s); 222 block_peak = local_max(block_peak, s); 223 } 224 samples -= n; 225 if(AnalyzeSamples(lbuffer, rbuffer, n, 2) != GAIN_ANALYSIS_OK) 226 return false; 227 } 228 } 229 else { 230 j = 0; 231 while(samples > 0) { 232 const unsigned n = local_min(samples, nbuffer); 233 for(i = 0; i < n; i++, j++) { 234 s = input[0][j]; 235 lbuffer[i] = (Float_t)(scale * (double)s); 236 s = abs(s); 237 block_peak = local_max(block_peak, s); 238 } 239 samples -= n; 240 if(AnalyzeSamples(lbuffer, 0, n, 1) != GAIN_ANALYSIS_OK) 241 return false; 242 } 243 } 244 } 245 246 { 247 const double peak_scale = (double)(1u << (bps - 1)); 248 double peak = (double)block_peak / peak_scale; 249 if(peak > title_peak_) 250 title_peak_ = peak; 251 if(peak > album_peak_) 252 album_peak_ = peak; 253 } 254 255 return true; 256} 257 258void grabbag__replaygain_get_album(float *gain, float *peak) 259{ 260 *gain = (float)GetAlbumGain(); 261 *peak = (float)album_peak_; 262 album_peak_ = 0.0; 263} 264 265void grabbag__replaygain_get_title(float *gain, float *peak) 266{ 267 *gain = (float)GetTitleGain(); 268 *peak = (float)title_peak_; 269 title_peak_ = 0.0; 270} 271 272 273typedef struct { 274 unsigned channels; 275 unsigned bits_per_sample; 276 unsigned sample_rate; 277 FLAC__bool error; 278} DecoderInstance; 279 280static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data) 281{ 282 DecoderInstance *instance = (DecoderInstance*)client_data; 283 const unsigned bits_per_sample = frame->header.bits_per_sample; 284 const unsigned channels = frame->header.channels; 285 const unsigned sample_rate = frame->header.sample_rate; 286 const unsigned samples = frame->header.blocksize; 287 288 (void)decoder; 289 290 if( 291 !instance->error && 292 (channels == 2 || channels == 1) && 293 bits_per_sample == instance->bits_per_sample && 294 channels == instance->channels && 295 sample_rate == instance->sample_rate 296 ) { 297 instance->error = !grabbag__replaygain_analyze(buffer, channels==2, bits_per_sample, samples); 298 } 299 else { 300 instance->error = true; 301 } 302 303 if(!instance->error) 304 return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE; 305 else 306 return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT; 307} 308 309static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data) 310{ 311 DecoderInstance *instance = (DecoderInstance*)client_data; 312 313 (void)decoder; 314 315 if(metadata->type == FLAC__METADATA_TYPE_STREAMINFO) { 316 instance->bits_per_sample = metadata->data.stream_info.bits_per_sample; 317 instance->channels = metadata->data.stream_info.channels; 318 instance->sample_rate = metadata->data.stream_info.sample_rate; 319 320 if(instance->channels != 1 && instance->channels != 2) { 321 instance->error = true; 322 return; 323 } 324 325 if(!grabbag__replaygain_is_valid_sample_frequency(instance->sample_rate)) { 326 instance->error = true; 327 return; 328 } 329 } 330} 331 332static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data) 333{ 334 DecoderInstance *instance = (DecoderInstance*)client_data; 335 336 (void)decoder, (void)status; 337 338 instance->error = true; 339} 340 341const char *grabbag__replaygain_analyze_file(const char *filename, float *title_gain, float *title_peak) 342{ 343 DecoderInstance instance; 344 FLAC__StreamDecoder *decoder = FLAC__stream_decoder_new(); 345 346 if(0 == decoder) 347 return "memory allocation error"; 348 349 instance.error = false; 350 351 /* It does these three by default but lets be explicit: */ 352 FLAC__stream_decoder_set_md5_checking(decoder, false); 353 FLAC__stream_decoder_set_metadata_ignore_all(decoder); 354 FLAC__stream_decoder_set_metadata_respond(decoder, FLAC__METADATA_TYPE_STREAMINFO); 355 356 if(FLAC__stream_decoder_init_file(decoder, filename, write_callback_, metadata_callback_, error_callback_, &instance) != FLAC__STREAM_DECODER_INIT_STATUS_OK) { 357 FLAC__stream_decoder_delete(decoder); 358 return "initializing decoder"; 359 } 360 361 if(!FLAC__stream_decoder_process_until_end_of_stream(decoder) || instance.error) { 362 FLAC__stream_decoder_delete(decoder); 363 return "decoding file"; 364 } 365 366 FLAC__stream_decoder_delete(decoder); 367 368 grabbag__replaygain_get_title(title_gain, title_peak); 369 370 return 0; 371} 372 373const char *grabbag__replaygain_store_to_vorbiscomment(FLAC__StreamMetadata *block, float album_gain, float album_peak, float title_gain, float title_peak) 374{ 375 const char *error; 376 377 if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_reference(block))) 378 return error; 379 380 if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_title(block, title_gain, title_peak))) 381 return error; 382 383 if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_album(block, album_gain, album_peak))) 384 return error; 385 386 return 0; 387} 388 389const char *grabbag__replaygain_store_to_vorbiscomment_reference(FLAC__StreamMetadata *block) 390{ 391 FLAC__ASSERT(0 != block); 392 FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT); 393 394 if(FLAC__metadata_object_vorbiscomment_remove_entries_matching(block, (const char *)GRABBAG__REPLAYGAIN_TAG_REFERENCE_LOUDNESS) < 0) 395 return "memory allocation error"; 396 397 if(!append_tag_(block, reference_format_, GRABBAG__REPLAYGAIN_TAG_REFERENCE_LOUDNESS, ReplayGainReferenceLoudness)) 398 return "memory allocation error"; 399 400 return 0; 401} 402 403const char *grabbag__replaygain_store_to_vorbiscomment_album(FLAC__StreamMetadata *block, float album_gain, float album_peak) 404{ 405 FLAC__ASSERT(0 != block); 406 FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT); 407 408 if( 409 FLAC__metadata_object_vorbiscomment_remove_entries_matching(block, (const char *)GRABBAG__REPLAYGAIN_TAG_ALBUM_GAIN) < 0 || 410 FLAC__metadata_object_vorbiscomment_remove_entries_matching(block, (const char *)GRABBAG__REPLAYGAIN_TAG_ALBUM_PEAK) < 0 411 ) 412 return "memory allocation error"; 413 414 if( 415 !append_tag_(block, gain_format_, GRABBAG__REPLAYGAIN_TAG_ALBUM_GAIN, album_gain) || 416 !append_tag_(block, peak_format_, GRABBAG__REPLAYGAIN_TAG_ALBUM_PEAK, album_peak) 417 ) 418 return "memory allocation error"; 419 420 return 0; 421} 422 423const char *grabbag__replaygain_store_to_vorbiscomment_title(FLAC__StreamMetadata *block, float title_gain, float title_peak) 424{ 425 FLAC__ASSERT(0 != block); 426 FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT); 427 428 if( 429 FLAC__metadata_object_vorbiscomment_remove_entries_matching(block, (const char *)GRABBAG__REPLAYGAIN_TAG_TITLE_GAIN) < 0 || 430 FLAC__metadata_object_vorbiscomment_remove_entries_matching(block, (const char *)GRABBAG__REPLAYGAIN_TAG_TITLE_PEAK) < 0 431 ) 432 return "memory allocation error"; 433 434 if( 435 !append_tag_(block, gain_format_, GRABBAG__REPLAYGAIN_TAG_TITLE_GAIN, title_gain) || 436 !append_tag_(block, peak_format_, GRABBAG__REPLAYGAIN_TAG_TITLE_PEAK, title_peak) 437 ) 438 return "memory allocation error"; 439 440 return 0; 441} 442 443static const char *store_to_file_pre_(const char *filename, FLAC__Metadata_Chain **chain, FLAC__StreamMetadata **block) 444{ 445 FLAC__Metadata_Iterator *iterator; 446 const char *error; 447 FLAC__bool found_vc_block = false; 448 449 if(0 == (*chain = FLAC__metadata_chain_new())) 450 return "memory allocation error"; 451 452 if(!FLAC__metadata_chain_read(*chain, filename)) { 453 error = FLAC__Metadata_ChainStatusString[FLAC__metadata_chain_status(*chain)]; 454 FLAC__metadata_chain_delete(*chain); 455 return error; 456 } 457 458 if(0 == (iterator = FLAC__metadata_iterator_new())) { 459 FLAC__metadata_chain_delete(*chain); 460 return "memory allocation error"; 461 } 462 463 FLAC__metadata_iterator_init(iterator, *chain); 464 465 do { 466 *block = FLAC__metadata_iterator_get_block(iterator); 467 if((*block)->type == FLAC__METADATA_TYPE_VORBIS_COMMENT) 468 found_vc_block = true; 469 } while(!found_vc_block && FLAC__metadata_iterator_next(iterator)); 470 471 if(!found_vc_block) { 472 /* create a new block */ 473 *block = FLAC__metadata_object_new(FLAC__METADATA_TYPE_VORBIS_COMMENT); 474 if(0 == *block) { 475 FLAC__metadata_chain_delete(*chain); 476 FLAC__metadata_iterator_delete(iterator); 477 return "memory allocation error"; 478 } 479 while(FLAC__metadata_iterator_next(iterator)) 480 ; 481 if(!FLAC__metadata_iterator_insert_block_after(iterator, *block)) { 482 error = FLAC__Metadata_ChainStatusString[FLAC__metadata_chain_status(*chain)]; 483 FLAC__metadata_chain_delete(*chain); 484 FLAC__metadata_iterator_delete(iterator); 485 return error; 486 } 487 /* iterator is left pointing to new block */ 488 FLAC__ASSERT(FLAC__metadata_iterator_get_block(iterator) == *block); 489 } 490 491 FLAC__metadata_iterator_delete(iterator); 492 493 FLAC__ASSERT(0 != *block); 494 FLAC__ASSERT((*block)->type == FLAC__METADATA_TYPE_VORBIS_COMMENT); 495 496 return 0; 497} 498 499static const char *store_to_file_post_(const char *filename, FLAC__Metadata_Chain *chain, FLAC__bool preserve_modtime) 500{ 501 struct stat stats; 502 const FLAC__bool have_stats = get_file_stats_(filename, &stats); 503 504 (void)grabbag__file_change_stats(filename, /*read_only=*/false); 505 506 FLAC__metadata_chain_sort_padding(chain); 507 if(!FLAC__metadata_chain_write(chain, /*use_padding=*/true, preserve_modtime)) { 508 FLAC__metadata_chain_delete(chain); 509 return FLAC__Metadata_ChainStatusString[FLAC__metadata_chain_status(chain)]; 510 } 511 512 FLAC__metadata_chain_delete(chain); 513 514 if(have_stats) 515 set_file_stats_(filename, &stats); 516 517 return 0; 518} 519 520const char *grabbag__replaygain_store_to_file(const char *filename, float album_gain, float album_peak, float title_gain, float title_peak, FLAC__bool preserve_modtime) 521{ 522 FLAC__Metadata_Chain *chain; 523 FLAC__StreamMetadata *block; 524 const char *error; 525 526 if(0 != (error = store_to_file_pre_(filename, &chain, &block))) 527 return error; 528 529 if(0 != (error = grabbag__replaygain_store_to_vorbiscomment(block, album_gain, album_peak, title_gain, title_peak))) { 530 FLAC__metadata_chain_delete(chain); 531 return error; 532 } 533 534 if(0 != (error = store_to_file_post_(filename, chain, preserve_modtime))) 535 return error; 536 537 return 0; 538} 539 540const char *grabbag__replaygain_store_to_file_reference(const char *filename, FLAC__bool preserve_modtime) 541{ 542 FLAC__Metadata_Chain *chain; 543 FLAC__StreamMetadata *block; 544 const char *error; 545 546 if(0 != (error = store_to_file_pre_(filename, &chain, &block))) 547 return error; 548 549 if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_reference(block))) { 550 FLAC__metadata_chain_delete(chain); 551 return error; 552 } 553 554 if(0 != (error = store_to_file_post_(filename, chain, preserve_modtime))) 555 return error; 556 557 return 0; 558} 559 560const char *grabbag__replaygain_store_to_file_album(const char *filename, float album_gain, float album_peak, FLAC__bool preserve_modtime) 561{ 562 FLAC__Metadata_Chain *chain; 563 FLAC__StreamMetadata *block; 564 const char *error; 565 566 if(0 != (error = store_to_file_pre_(filename, &chain, &block))) 567 return error; 568 569 if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_album(block, album_gain, album_peak))) { 570 FLAC__metadata_chain_delete(chain); 571 return error; 572 } 573 574 if(0 != (error = store_to_file_post_(filename, chain, preserve_modtime))) 575 return error; 576 577 return 0; 578} 579 580const char *grabbag__replaygain_store_to_file_title(const char *filename, float title_gain, float title_peak, FLAC__bool preserve_modtime) 581{ 582 FLAC__Metadata_Chain *chain; 583 FLAC__StreamMetadata *block; 584 const char *error; 585 586 if(0 != (error = store_to_file_pre_(filename, &chain, &block))) 587 return error; 588 589 if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_title(block, title_gain, title_peak))) { 590 FLAC__metadata_chain_delete(chain); 591 return error; 592 } 593 594 if(0 != (error = store_to_file_post_(filename, chain, preserve_modtime))) 595 return error; 596 597 return 0; 598} 599 600static FLAC__bool parse_double_(const FLAC__StreamMetadata_VorbisComment_Entry *entry, double *val) 601{ 602 char s[32], *end; 603 const char *p, *q; 604 double v; 605 606 FLAC__ASSERT(0 != entry); 607 FLAC__ASSERT(0 != val); 608 609 p = (const char *)entry->entry; 610 q = strchr(p, '='); 611 if(0 == q) 612 return false; 613 q++; 614 memset(s, 0, sizeof(s)-1); 615 strncpy(s, q, local_min(sizeof(s)-1, entry->length - (q-p))); 616 617 v = strtod(s, &end); 618 if(end == s) 619 return false; 620 621 *val = v; 622 return true; 623} 624 625FLAC__bool grabbag__replaygain_load_from_vorbiscomment(const FLAC__StreamMetadata *block, FLAC__bool album_mode, FLAC__bool strict, double *reference, double *gain, double *peak) 626{ 627 int reference_offset, gain_offset, peak_offset; 628 629 FLAC__ASSERT(0 != block); 630 FLAC__ASSERT(0 != reference); 631 FLAC__ASSERT(0 != gain); 632 FLAC__ASSERT(0 != peak); 633 FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT); 634 635 /* Default to current level until overridden by a detected tag; this 636 * will always be true until we change replaygain_analysis.c 637 */ 638 *reference = ReplayGainReferenceLoudness; 639 640 if(0 <= (reference_offset = FLAC__metadata_object_vorbiscomment_find_entry_from(block, /*offset=*/0, (const char *)GRABBAG__REPLAYGAIN_TAG_REFERENCE_LOUDNESS))) 641 (void)parse_double_(block->data.vorbis_comment.comments + reference_offset, reference); 642 643 if(0 > (gain_offset = FLAC__metadata_object_vorbiscomment_find_entry_from(block, /*offset=*/0, (const char *)(album_mode? GRABBAG__REPLAYGAIN_TAG_ALBUM_GAIN : GRABBAG__REPLAYGAIN_TAG_TITLE_GAIN)))) 644 return !strict && grabbag__replaygain_load_from_vorbiscomment(block, !album_mode, /*strict=*/true, reference, gain, peak); 645 if(0 > (peak_offset = FLAC__metadata_object_vorbiscomment_find_entry_from(block, /*offset=*/0, (const char *)(album_mode? GRABBAG__REPLAYGAIN_TAG_ALBUM_PEAK : GRABBAG__REPLAYGAIN_TAG_TITLE_PEAK)))) 646 return !strict && grabbag__replaygain_load_from_vorbiscomment(block, !album_mode, /*strict=*/true, reference, gain, peak); 647 648 if(!parse_double_(block->data.vorbis_comment.comments + gain_offset, gain)) 649 return !strict && grabbag__replaygain_load_from_vorbiscomment(block, !album_mode, /*strict=*/true, reference, gain, peak); 650 if(!parse_double_(block->data.vorbis_comment.comments + peak_offset, peak)) 651 return !strict && grabbag__replaygain_load_from_vorbiscomment(block, !album_mode, /*strict=*/true, reference, gain, peak); 652 653 return true; 654} 655 656double grabbag__replaygain_compute_scale_factor(double peak, double gain, double preamp, FLAC__bool prevent_clipping) 657{ 658 double scale; 659 FLAC__ASSERT(peak >= 0.0); 660 gain += preamp; 661 scale = (float) pow(10.0, gain * 0.05); 662 if(prevent_clipping && peak > 0.0) { 663 const double max_scale = (float)(1.0 / peak); 664 if(scale > max_scale) 665 scale = max_scale; 666 } 667 return scale; 668} 669