flac_afh.c

   1 /* Copyright (C) 2011 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file flac_afh.c Audio format handler for flac files. */
   4
   5 #include <regex.h>
   6 #include <FLAC/stream_decoder.h>
   7 #include <FLAC/metadata.h>
   8
   9 #include "para.h"
  10 #include "error.h"
  11 #include "afh.h"
  12 #include "string.h"
  13 #include "fd.h"
  14
  15 struct private_flac_afh_data {
  16         const char *map;
  17         size_t map_bytes;
  18         size_t fpos;
  19         struct afh_info *afhi;
  20         unsigned blocksize;
  21 };
  22
  23 static size_t copy_data(struct private_flac_afh_data *pfad, void *buf,
  24                 size_t want)
  25 {
  26         size_t copy, have = pfad->map_bytes - pfad->fpos;
  27
  28         if (have == 0)
  29                 return 0;
  30         copy = have < want? have : want;
  31         memcpy(buf, pfad->map + pfad->fpos, copy);
  32         pfad->fpos += copy;
  33         return copy;
  34 }
  35
  36 static size_t meta_read_cb(void *ptr, size_t size, size_t nmemb,
  37                 FLAC__IOHandle handle)
  38 {
  39         struct private_flac_afh_data *pfad = handle;
  40         return copy_data(pfad, ptr, nmemb * size);
  41 }
  42
  43 static int meta_seek_cb(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
  44 {
  45         struct private_flac_afh_data *pfad = handle;
  46
  47         if (offset < 0)
  48                 return -1;
  49
  50         switch (whence) {
  51         case SEEK_SET:
  52                 if (offset >= pfad->map_bytes)
  53                         return -1;
  54                 pfad->fpos = offset;
  55                 return 0;
  56         case SEEK_CUR:
  57                 if (pfad->fpos + offset >= pfad->map_bytes)
  58                         return -1;
  59                 pfad->fpos += offset;
  60                 return 0;
  61         case SEEK_END:
  62                 if (offset >= pfad->map_bytes)
  63                         return -1;
  64                 pfad->fpos = offset;
  65                 return 0;
  66         default:
  67                 return -1;
  68         }
  69 }
  70
  71 static FLAC__int64 meta_tell_cb(FLAC__IOHandle handle)
  72 {
  73         struct private_flac_afh_data *pfad = handle;
  74         return pfad->fpos;
  75 }
  76
  77 static int meta_eof_cb(FLAC__IOHandle handle)
  78 {
  79         struct private_flac_afh_data *pfad = handle;
  80         return pfad->fpos == pfad->map_bytes;
  81 }
  82
  83 static int meta_close_cb(FLAC__IOHandle __a_unused handle)
  84 {
  85         return 0;
  86 }
  87
  88 static const FLAC__IOCallbacks meta_callbacks = {
  89         .read = meta_read_cb,
  90         .write = NULL,
  91         .seek = meta_seek_cb,
  92         .tell = meta_tell_cb,
  93         .eof = meta_eof_cb,
  94         .close = meta_close_cb
  95 };
  96
  97 static void free_tags(struct taginfo *tags)
  98 {
  99         freep(&tags->artist);
 100         freep(&tags->title);
 101         freep(&tags->album);
 102         freep(&tags->year);
 103         freep(&tags->comment);
 104 }
 105
 106 static bool copy_if_tag_type(const char *tag, int taglen, const char *type,
 107                 char **p)
 108 {
 109         char *q = key_value_copy(tag, taglen, type);
 110         if (!q)
 111                 return false;
 112         free(*p);
 113         *p = q;
 114         return true;
 115 }
 116
 117 static void flac_read_vorbis_comments(FLAC__StreamMetadata_VorbisComment *vc,
 118                 struct taginfo *tags)
 119 {
 120         int i;
 121         FLAC__StreamMetadata_VorbisComment_Entry *comment = vc->comments;
 122
 123         PARA_INFO_LOG("found %u vorbis comments\n", vc->num_comments);
 124         for (i = 0; i < vc->num_comments; i++) {
 125                 char *e = (char *)comment[i].entry;
 126                 int len = comment[i].length;
 127                 if (copy_if_tag_type(e, len, "artist", &tags->artist))
 128                         continue;
 129                 if (copy_if_tag_type(e, len, "title", &tags->title))
 130                         continue;
 131                 if (copy_if_tag_type(e, len, "album", &tags->album))
 132                         continue;
 133                 if (copy_if_tag_type(e, len, "year", &tags->year))
 134                         continue;
 135                 if (copy_if_tag_type(e, len, "comment", &tags->comment))
 136                         continue;
 137         }
 138 }
 139
 140 /*
 141  * FLAC__metadata_object_vorbiscomment_replace_comment() is buggy in some
 142  * libFLAC versions (see commit e95399c1 in the flac git repository). Hence we
 143  * use delete and add as a workaround.
 144  */
 145 static int flac_replace_vorbis_comment(FLAC__StreamMetadata *b,
 146                 const char *tag, const char* val)
 147 {
 148         FLAC__bool ok;
 149         FLAC__StreamMetadata_VorbisComment_Entry entry;
 150         int ret;
 151
 152         PARA_INFO_LOG("replacing %s\n", tag);
 153         ret = FLAC__metadata_object_vorbiscomment_remove_entries_matching(
 154                 b, tag);
 155         if (ret < 0)
 156                 return -E_FLAC_REPLACE_COMMENT;
 157         ok = FLAC__metadata_object_vorbiscomment_entry_from_name_value_pair(
 158                 &entry, tag, val? val : "");
 159         if (!ok)
 160                 return -E_FLAC_REPLACE_COMMENT;
 161         ok = FLAC__metadata_object_vorbiscomment_append_comment(b, entry,
 162                 false /* no copy */);
 163         if (!ok) {
 164                 free(entry.entry);
 165                 return -E_FLAC_REPLACE_COMMENT;
 166         }
 167         return 1;
 168 }
 169
 170 static int flac_replace_vorbis_comments(FLAC__Metadata_Chain *chain,
 171                 FLAC__StreamMetadata *b, struct taginfo *tags)
 172 {
 173         FLAC__bool ok;
 174         int ret;
 175
 176         ret = flac_replace_vorbis_comment(b, "artist", tags->artist);
 177         if (ret < 0)
 178                 return ret;
 179         ret = flac_replace_vorbis_comment(b, "title", tags->title);
 180         if (ret < 0)
 181                 return ret;
 182         ret = flac_replace_vorbis_comment(b, "album", tags->album);
 183         if (ret < 0)
 184                 return ret;
 185         ret = flac_replace_vorbis_comment(b, "year", tags->year);
 186         if (ret < 0)
 187                 return ret;
 188         ret = flac_replace_vorbis_comment(b, "comment", tags->comment);
 189         if (ret < 0)
 190                 return ret;
 191         /*
 192          * Even if padding is disabled, libflac will try to modify the original
 193          * file inplace if the metadata size has not changed. This won't work
 194          * here though, because the original file is mapped read-only. Since
 195          * there is no option to force the use of a temp file we work around
 196          * this shortcoming by adding a dummy entry which increases the size of
 197          * the meta data. If the entry already exists, we simply remove it.
 198          */
 199         ok = FLAC__metadata_chain_check_if_tempfile_needed(chain,
 200                 false /* no padding */);
 201         if (!ok) {
 202                 PARA_INFO_LOG("adding/removing dummy comment\n");
 203                 ret = FLAC__metadata_object_vorbiscomment_remove_entries_matching(
 204                         b, "comment2");
 205                 if (ret < 0)
 206                         return -E_FLAC_REPLACE_COMMENT;
 207                 if (ret == 0) { /* nothing was removed */
 208                         ret = flac_replace_vorbis_comment(b, "comment2",
 209                                 "avoid inplace write");
 210                         if (ret < 0)
 211                                 return ret;
 212                 }
 213                 assert(FLAC__metadata_chain_check_if_tempfile_needed(chain,
 214                         false /* no padding */));
 215         }
 216         return 1;
 217 }
 218
 219 static int flac_init_meta(struct private_flac_afh_data *pfad,
 220                 FLAC__Metadata_Chain **chainp, FLAC__Metadata_Iterator **iterp)
 221 {
 222         int ret;
 223         FLAC__bool ok;
 224         FLAC__Metadata_Chain *chain;
 225         FLAC__Metadata_Iterator *iter;
 226
 227         *chainp = NULL;
 228         *iterp = NULL;
 229         chain = FLAC__metadata_chain_new();
 230         if (!chain)
 231                 return -E_FLAC_CHAIN_ALLOC;
 232         ret = -E_FLAC_CHAIN_READ;
 233         ok = FLAC__metadata_chain_read_with_callbacks(chain, pfad,
 234                 meta_callbacks);
 235         if (!ok)
 236                 goto free_chain;
 237         ret = -E_FLAC_ITER_ALLOC;
 238         iter = FLAC__metadata_iterator_new();
 239         if (!iter)
 240                 goto free_chain;
 241         FLAC__metadata_iterator_init(iter, chain);
 242         *iterp = iter;
 243         *chainp = chain;
 244         return 1;
 245 free_chain:
 246         FLAC__metadata_chain_delete(chain);
 247         return ret;
 248 }
 249
 250 static int flac_read_meta(struct private_flac_afh_data *pfad)
 251 {
 252         int ret;
 253         FLAC__Metadata_Chain *chain;
 254         FLAC__Metadata_Iterator *iter;
 255         FLAC__StreamMetadata_StreamInfo *info = NULL;
 256         FLAC__bool ok;
 257
 258         ret = flac_init_meta(pfad, &chain, &iter);
 259         if (ret < 0)
 260                 return ret;
 261         for (;;) {
 262                 FLAC__StreamMetadata *b;
 263                 b = FLAC__metadata_iterator_get_block(iter);
 264                 if (!b)
 265                         break;
 266                 if (b->type == FLAC__METADATA_TYPE_STREAMINFO) {
 267                         info = &b->data.stream_info;
 268                         ret = -E_FLAC_VARBLOCK;
 269                         if (info->min_blocksize != info->max_blocksize)
 270                                 goto free_iter;
 271                         pfad->afhi->frequency = info->sample_rate;
 272                         pfad->afhi->channels = info->channels;
 273                         pfad->blocksize = info->min_blocksize;
 274                 }
 275                 if (b->type == FLAC__METADATA_TYPE_VORBIS_COMMENT)
 276                         flac_read_vorbis_comments(&b->data.vorbis_comment,
 277                                 &pfad->afhi->tags);
 278                 ok = FLAC__metadata_iterator_next(iter);
 279                 if (!ok)
 280                         break;
 281         }
 282         ret = info? 0: -E_FLAC_STREAMINFO;
 283 free_iter:
 284         FLAC__metadata_iterator_delete(iter);
 285         FLAC__metadata_chain_delete(chain);
 286         if (ret < 0)
 287                 free_tags(&pfad->afhi->tags);
 288         return ret;
 289 }
 290
 291 static FLAC__StreamDecoderReadStatus read_cb(
 292                 __a_unused const FLAC__StreamDecoder *decoder,
 293                 FLAC__byte buffer[], size_t *bytes, void *client_data)
 294 {
 295         struct private_flac_afh_data *pfad = client_data;
 296
 297         assert(*bytes > 0);
 298         *bytes = copy_data(pfad, buffer, *bytes);
 299         if (*bytes == 0)
 300                 return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
 301         else
 302                 return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
 303 }
 304
 305 static FLAC__StreamDecoderTellStatus tell_cb(
 306                 __a_unused const FLAC__StreamDecoder *decoder,
 307                 FLAC__uint64 *absolute_byte_offset, void *client_data)
 308 {
 309         struct private_flac_afh_data *pfad = client_data;
 310
 311         *absolute_byte_offset = pfad->fpos;
 312         return FLAC__STREAM_DECODER_TELL_STATUS_OK;
 313 }
 314
 315 /* libflac insists on this callback being present. */
 316 static FLAC__StreamDecoderWriteStatus write_cb(
 317                 __a_unused const FLAC__StreamDecoder *decoder,
 318                 __a_unused const FLAC__Frame *frame,
 319                 __a_unused const FLAC__int32 *const buffer[],
 320                 __a_unused void *client_data)
 321 {
 322         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 323 }
 324
 325 static void error_cb(
 326                 __a_unused const FLAC__StreamDecoder *decoder,
 327                 FLAC__StreamDecoderErrorStatus status,
 328                 __a_unused void *client_data)
 329 {
 330         PARA_ERROR_LOG("%s\n", FLAC__StreamDecoderErrorStatusString[status]);
 331 }
 332
 333 static int flac_afh_read_chunks(struct private_flac_afh_data *pfad)
 334 {
 335         FLAC__StreamDecoder *decoder;
 336         FLAC__StreamDecoderInitStatus init_status;
 337         FLAC__bool ok;
 338         FLAC__uint64 c;
 339         unsigned chunk_table_size = 0;
 340         int ret;
 341         struct afh_info *afhi = pfad->afhi;
 342
 343         PARA_INFO_LOG("reading chunk table\n");
 344         afhi->chunk_table = NULL;
 345         decoder = FLAC__stream_decoder_new();
 346         if (!decoder)
 347                 return -E_FLAC_AFH_DECODER_ALLOC;
 348         ret = -E_FLAC_AFH_DECODER_INIT;
 349         init_status = FLAC__stream_decoder_init_stream(
 350                 decoder,
 351                 read_cb,
 352                 NULL, /* seek */
 353                 tell_cb,
 354                 NULL, /* length */
 355                 NULL, /* eof */
 356                 write_cb,
 357                 NULL,
 358                 error_cb,
 359                 pfad
 360         );
 361         if (init_status != FLAC__STREAM_DECODER_INIT_STATUS_OK)
 362                 goto free_decoder;
 363         ret = -E_FLAC_SKIP_META;
 364         ok = FLAC__stream_decoder_process_until_end_of_metadata(decoder);
 365         if (!ok)
 366                 goto free_decoder;
 367         for (c = 0;; c++) {
 368                 FLAC__uint64 pos;
 369                 FLAC__StreamDecoderState state;
 370
 371                 ret = -E_FLAC_DECODE_POS;
 372                 ok = FLAC__stream_decoder_get_decode_position(decoder, &pos);
 373                 if (!ok)
 374                         goto free_decoder;
 375                 if (c >= chunk_table_size) {
 376                         chunk_table_size = 2 * chunk_table_size + 100;
 377                         afhi->chunk_table = para_realloc(afhi->chunk_table,
 378                                 chunk_table_size * sizeof(uint32_t));
 379                 }
 380                 afhi->chunk_table[c] = pos;
 381
 382                 ok = FLAC__stream_decoder_skip_single_frame(decoder);
 383                 if (!ok)
 384                         break;
 385                 state = FLAC__stream_decoder_get_state(decoder);
 386                 if (state == FLAC__STREAM_DECODER_END_OF_STREAM)
 387                         break;
 388         }
 389         afhi->chunks_total = c;
 390         set_max_chunk_size(afhi);
 391         ret = 1;
 392 free_decoder:
 393         FLAC__stream_decoder_finish(decoder);
 394         FLAC__stream_decoder_delete(decoder);
 395         if (ret < 0)
 396                 freep(&afhi->chunk_table);
 397         return ret;
 398 }
 399
 400 static int flac_get_file_info(char *map, size_t map_bytes, __a_unused int fd,
 401                 struct afh_info *afhi)
 402 {
 403         struct private_flac_afh_data pfad_struct = {
 404                 .map = map,
 405                 .map_bytes = map_bytes,
 406                 .afhi = afhi
 407         }, *pfad = &pfad_struct;
 408         int ret;
 409         double chunk_time;
 410
 411         afhi->header_len = 0;
 412         ret = flac_read_meta(pfad);
 413         if (ret < 0)
 414                 return ret;
 415         pfad->fpos = 0;
 416         ret = flac_afh_read_chunks(pfad);
 417         if (ret < 0) {
 418                 free_tags(&afhi->tags);
 419                 return ret;
 420         }
 421         afhi->techinfo = make_message("blocksize: %u", pfad->blocksize);
 422         afhi->seconds_total = DIV_ROUND_UP(afhi->chunks_total * pfad->blocksize,
 423                 afhi->frequency);
 424         afhi->bitrate = pfad->map_bytes * 8 / afhi->seconds_total / 1024;
 425         chunk_time = (double)pfad->blocksize / afhi->frequency;
 426         afhi->chunk_tv.tv_sec = chunk_time;
 427         chunk_time *= 1000 * 1000;
 428         chunk_time -= afhi->chunk_tv.tv_sec * 1000 * 1000;
 429         afhi->chunk_tv.tv_usec = chunk_time;
 430         return 1;
 431 }
 432
 433 static size_t temp_write_cb(const void *ptr, size_t size, size_t nmemb,
 434         FLAC__IOHandle handle)
 435 {
 436         int ret, fd = *(int *)handle;
 437         size_t n = size * nmemb; /* FIXME: possible overflow */
 438
 439         ret = write_all(fd, ptr, n);
 440
 441         /*
 442          * libflac expects POSIX semantics: If an error occurs, or the end of
 443          * the file is reached, the return value is a short item count or zero.
 444          */
 445         if (ret < 0) {
 446                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 447                 return 0;
 448         }
 449         return nmemb;
 450 }
 451
 452 /* only the write callback needs to be supplied for writing the temp file. */
 453 static const FLAC__IOCallbacks temp_callbacks = {
 454         .write = temp_write_cb,
 455 };
 456
 457 static int flac_write_chain(FLAC__Metadata_Chain *chain,
 458                 struct private_flac_afh_data *pfad, int fd)
 459 {
 460         FLAC__bool ok;
 461
 462         ok = FLAC__metadata_chain_write_with_callbacks_and_tempfile(chain,
 463                 false /* no padding*/, pfad,
 464                 meta_callbacks, &fd, temp_callbacks);
 465         if (!ok) {
 466                 FLAC__Metadata_ChainStatus st;
 467                 st = FLAC__metadata_chain_status(chain);
 468                 PARA_ERROR_LOG("chain status: %u\n", st);
 469                 if (st == FLAC__METADATA_CHAIN_STATUS_READ_ERROR)
 470                         PARA_ERROR_LOG("read error\n");
 471                 return -E_FLAC_WRITE_CHAIN;
 472         }
 473         return 1;
 474 }
 475
 476 static int flac_rewrite_tags(const char *map, size_t map_bytes,
 477                 struct taginfo *tags, int fd, __a_unused const char *filename)
 478 {
 479         int ret;
 480         FLAC__Metadata_Chain *chain;
 481         FLAC__Metadata_Iterator *iter;
 482         FLAC__StreamMetadata *b = NULL;
 483         FLAC__bool ok;
 484         struct private_flac_afh_data *pfad = para_calloc(sizeof(*pfad));
 485
 486         pfad->map = map;
 487         pfad->map_bytes = map_bytes;
 488         pfad->fpos = 0;
 489
 490         ret = flac_init_meta(pfad, &chain, &iter);
 491         if (ret < 0)
 492                 goto free_pfad;
 493         for (ok = true; ok; ok = FLAC__metadata_iterator_next(iter)) {
 494                 b = FLAC__metadata_iterator_get_block(iter);
 495                 assert(b);
 496                 if (b->type == FLAC__METADATA_TYPE_VORBIS_COMMENT)
 497                         break;
 498                 b = NULL;
 499         }
 500         ret = -E_FLAC_REPLACE_COMMENT;
 501         if (!b)
 502                 goto out;
 503         ret = flac_replace_vorbis_comments(chain, b, tags);
 504         if (ret < 0)
 505                 goto out;
 506         ret = flac_write_chain(chain, pfad, fd);
 507 out:
 508         FLAC__metadata_iterator_delete(iter);
 509         FLAC__metadata_chain_delete(chain);
 510 free_pfad:
 511         free(pfad);
 512         return ret;
 513 }
 514
 515 static const char * const flac_suffixes[] = {"flac", NULL};
 516
 517 /**
 518  * The init function of the flac audio format handler.
 519  *
 520  * \param afh pointer to the struct to initialize
 521  */
 522 void flac_afh_init(struct audio_format_handler *afh)
 523 {
 524         afh->get_file_info = flac_get_file_info,
 525         afh->suffixes = flac_suffixes;
 526         afh->rewrite_tags = flac_rewrite_tags;
 527 }