flac_afh.c

   1 /*
   2  * Copyright (C) 2011-2014 Andre Noll <maan@tuebingen.mpg.de>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file flac_afh.c Audio format handler for flac files. */
   8
   9 #include <regex.h>
  10 #include <FLAC/stream_decoder.h>
  11 #include <FLAC/metadata.h>
  12
  13 #include "para.h"
  14 #include "error.h"
  15 #include "afh.h"
  16 #include "string.h"
  17
  18 struct private_flac_afh_data {
  19         char *map;
  20         size_t map_bytes;
  21         size_t fpos;
  22         struct afh_info *afhi;
  23         unsigned blocksize;
  24 };
  25
  26 static size_t copy_data(struct private_flac_afh_data *pfad, void *buf,
  27                 size_t want)
  28 {
  29         size_t copy, have = pfad->map_bytes - pfad->fpos;
  30
  31         if (have == 0)
  32                 return 0;
  33         copy = have < want? have : want;
  34         memcpy(buf, pfad->map + pfad->fpos, copy);
  35         pfad->fpos += copy;
  36         return copy;
  37 }
  38
  39 static size_t meta_read_cb(void *ptr, size_t size, size_t nmemb,
  40                 FLAC__IOHandle handle)
  41 {
  42         struct private_flac_afh_data *pfad = handle;
  43         return copy_data(pfad, ptr, nmemb * size);
  44 }
  45
  46 static int meta_seek_cb(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
  47 {
  48         struct private_flac_afh_data *pfad = handle;
  49
  50         if (offset < 0)
  51                 return -1;
  52
  53         switch (whence) {
  54         case SEEK_SET:
  55                 if (offset >= pfad->map_bytes)
  56                         return -1;
  57                 pfad->fpos = offset;
  58                 return 0;
  59         case SEEK_CUR:
  60                 if (pfad->fpos + offset >= pfad->map_bytes)
  61                         return -1;
  62                 pfad->fpos += offset;
  63                 return 0;
  64         case SEEK_END:
  65                 if (offset >= pfad->map_bytes)
  66                         return -1;
  67                 pfad->fpos = offset;
  68                 return 0;
  69         default:
  70                 return -1;
  71         }
  72 }
  73
  74 static FLAC__int64 meta_tell_cb(FLAC__IOHandle handle)
  75 {
  76         struct private_flac_afh_data *pfad = handle;
  77         return pfad->fpos;
  78 }
  79
  80 static int meta_eof_cb(FLAC__IOHandle handle)
  81 {
  82         struct private_flac_afh_data *pfad = handle;
  83         return pfad->fpos == pfad->map_bytes;
  84 }
  85
  86 static int meta_close_cb(FLAC__IOHandle __a_unused handle)
  87 {
  88         return 0;
  89 }
  90
  91 static void free_tags(struct taginfo *tags)
  92 {
  93         freep(&tags->artist);
  94         freep(&tags->title);
  95         freep(&tags->album);
  96         freep(&tags->year);
  97         freep(&tags->comment);
  98 }
  99
 100 static bool copy_if_tag_type(const char *tag, int taglen, const char *type,
 101                 char **p)
 102 {
 103         char *q = key_value_copy(tag, taglen, type);
 104         if (!q)
 105                 return false;
 106         free(*p);
 107         *p = q;
 108         return true;
 109 }
 110
 111 static void flac_read_vorbis_comments(FLAC__StreamMetadata_VorbisComment *vc,
 112                 struct taginfo *tags)
 113 {
 114         int i;
 115         FLAC__StreamMetadata_VorbisComment_Entry *comment = vc->comments;
 116
 117         PARA_INFO_LOG("found %u vorbis comments\n", vc->num_comments);
 118         for (i = 0; i < vc->num_comments; i++) {
 119                 char *e = (char *)comment[i].entry;
 120                 int len = comment[i].length;
 121                 if (copy_if_tag_type(e, len, "artist", &tags->artist))
 122                         continue;
 123                 if (copy_if_tag_type(e, len, "title", &tags->title))
 124                         continue;
 125                 if (copy_if_tag_type(e, len, "album", &tags->album))
 126                         continue;
 127                 if (copy_if_tag_type(e, len, "year", &tags->year))
 128                         continue;
 129                 if (copy_if_tag_type(e, len, "comment", &tags->comment))
 130                         continue;
 131         }
 132 }
 133
 134 static int flac_read_meta(struct private_flac_afh_data *pfad)
 135 {
 136         int ret;
 137         FLAC__IOCallbacks meta_callbacks = {
 138                 .read = meta_read_cb,
 139                 .write = NULL,
 140                 .seek = meta_seek_cb,
 141                 .tell = meta_tell_cb,
 142                 .eof = meta_eof_cb,
 143                 .close = meta_close_cb
 144         };
 145         FLAC__Metadata_Chain *chain;
 146         FLAC__Metadata_Iterator *iter;
 147         FLAC__StreamMetadata_StreamInfo *info = NULL;
 148         FLAC__bool ok;
 149
 150         chain = FLAC__metadata_chain_new();
 151         if (!chain)
 152                 return -E_FLAC_CHAIN_ALLOC;
 153         ret = -E_FLAC_CHAIN_READ;
 154         ok = FLAC__metadata_chain_read_with_callbacks(chain, pfad,
 155                 meta_callbacks);
 156         if (!ok)
 157                 goto free_chain;
 158         ret = -E_FLAC_ITER_ALLOC;
 159         iter = FLAC__metadata_iterator_new();
 160         if (!iter)
 161                 goto free_chain;
 162         FLAC__metadata_iterator_init(iter, chain);
 163         for (;;) {
 164                 FLAC__StreamMetadata *b;
 165                 b = FLAC__metadata_iterator_get_block(iter);
 166                 if (!b)
 167                         break;
 168                 if (b->type == FLAC__METADATA_TYPE_STREAMINFO) {
 169                         info = &b->data.stream_info;
 170                         ret = -E_FLAC_VARBLOCK;
 171                         if (info->min_blocksize != info->max_blocksize)
 172                                 goto free_iter;
 173                         pfad->afhi->frequency = info->sample_rate;
 174                         pfad->afhi->channels = info->channels;
 175                         pfad->blocksize = info->min_blocksize;
 176                 }
 177                 if (b->type == FLAC__METADATA_TYPE_VORBIS_COMMENT)
 178                         flac_read_vorbis_comments(&b->data.vorbis_comment,
 179                                 &pfad->afhi->tags);
 180                 ok = FLAC__metadata_iterator_next(iter);
 181                 if (!ok)
 182                         break;
 183         }
 184         ret = info? 0: -E_FLAC_STREAMINFO;
 185 free_iter:
 186         FLAC__metadata_iterator_delete(iter);
 187 free_chain:
 188         FLAC__metadata_chain_delete(chain);
 189         if (ret < 0)
 190                 free_tags(&pfad->afhi->tags);
 191         return ret;
 192 }
 193
 194 static FLAC__StreamDecoderReadStatus read_cb(
 195                 __a_unused const FLAC__StreamDecoder *decoder,
 196                 FLAC__byte buffer[], size_t *bytes, void *client_data)
 197 {
 198         struct private_flac_afh_data *pfad = client_data;
 199
 200         assert(*bytes > 0);
 201         *bytes = copy_data(pfad, buffer, *bytes);
 202         if (*bytes == 0)
 203                 return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
 204         else
 205                 return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
 206 }
 207
 208 static FLAC__StreamDecoderTellStatus tell_cb(
 209                 __a_unused const FLAC__StreamDecoder *decoder,
 210                 FLAC__uint64 *absolute_byte_offset, void *client_data)
 211 {
 212         struct private_flac_afh_data *pfad = client_data;
 213
 214         *absolute_byte_offset = pfad->fpos;
 215         return FLAC__STREAM_DECODER_TELL_STATUS_OK;
 216 }
 217
 218 /* libflac insits on this callback being present. */
 219 static FLAC__StreamDecoderWriteStatus write_cb(
 220                 __a_unused const FLAC__StreamDecoder *decoder,
 221                 __a_unused const FLAC__Frame *frame,
 222                 __a_unused const FLAC__int32 *const buffer[],
 223                 __a_unused void *client_data)
 224 {
 225         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 226 }
 227
 228 static void error_cb(
 229                 __a_unused const FLAC__StreamDecoder *decoder,
 230                 FLAC__StreamDecoderErrorStatus status,
 231                 __a_unused void *client_data)
 232 {
 233         PARA_ERROR_LOG("%s\n", FLAC__StreamDecoderErrorStatusString[status]);
 234 }
 235
 236 static int flac_afh_read_chunks(struct private_flac_afh_data *pfad)
 237 {
 238         FLAC__StreamDecoder *decoder;
 239         FLAC__StreamDecoderInitStatus init_status;
 240         FLAC__bool ok;
 241         FLAC__uint64 c;
 242         unsigned chunk_table_size = 0;
 243         int ret;
 244         struct afh_info *afhi = pfad->afhi;
 245
 246         PARA_INFO_LOG("reading chunk table\n");
 247         afhi->chunk_table = NULL;
 248         decoder = FLAC__stream_decoder_new();
 249         if (!decoder)
 250                 return -E_FLAC_AFH_DECODER_ALLOC;
 251         ret = -E_FLAC_AFH_DECODER_INIT;
 252         init_status = FLAC__stream_decoder_init_stream(
 253                 decoder,
 254                 read_cb,
 255                 NULL, /* seek */
 256                 tell_cb,
 257                 NULL, /* length */
 258                 NULL, /* eof */
 259                 write_cb,
 260                 NULL,
 261                 error_cb,
 262                 pfad
 263         );
 264         if (init_status != FLAC__STREAM_DECODER_INIT_STATUS_OK)
 265                 goto free_decoder;
 266         ret = -E_FLAC_SKIP_META;
 267         ok = FLAC__stream_decoder_process_until_end_of_metadata(decoder);
 268         if (!ok)
 269                 goto free_decoder;
 270         for (c = 0;; c++) {
 271                 FLAC__uint64 pos;
 272                 FLAC__StreamDecoderState state;
 273
 274                 ret = -E_FLAC_DECODE_POS;
 275                 ok = FLAC__stream_decoder_get_decode_position(decoder, &pos);
 276                 if (!ok)
 277                         goto free_decoder;
 278                 if (c >= chunk_table_size) {
 279                         chunk_table_size = 2 * chunk_table_size + 100;
 280                         afhi->chunk_table = para_realloc(afhi->chunk_table,
 281                                 chunk_table_size * sizeof(uint32_t));
 282                 }
 283                 afhi->chunk_table[c] = pos;
 284
 285                 ok = FLAC__stream_decoder_skip_single_frame(decoder);
 286                 if (!ok)
 287                         break;
 288                 state = FLAC__stream_decoder_get_state(decoder);
 289                 if (state == FLAC__STREAM_DECODER_END_OF_STREAM)
 290                         break;
 291         }
 292         afhi->chunks_total = c;
 293         ret = 1;
 294 free_decoder:
 295         FLAC__stream_decoder_finish(decoder);
 296         FLAC__stream_decoder_delete(decoder);
 297         if (ret < 0)
 298                 freep(&afhi->chunk_table);
 299         return ret;
 300 }
 301
 302 static int flac_get_file_info(char *map, size_t map_bytes, __a_unused int fd,
 303                 struct afh_info *afhi)
 304 {
 305         struct private_flac_afh_data pfad_struct = {
 306                 .map = map,
 307                 .map_bytes = map_bytes,
 308                 .afhi = afhi
 309         }, *pfad = &pfad_struct;
 310         int ret;
 311         double chunk_time;
 312
 313         afhi->header_len = 0;
 314         ret = flac_read_meta(pfad);
 315         if (ret < 0)
 316                 return ret;
 317         pfad->fpos = 0;
 318         ret = flac_afh_read_chunks(pfad);
 319         if (ret < 0) {
 320                 free_tags(&afhi->tags);
 321                 return ret;
 322         }
 323         afhi->techinfo = make_message("blocksize: %u", pfad->blocksize);
 324         afhi->seconds_total = DIV_ROUND_UP(afhi->chunks_total * pfad->blocksize,
 325                 afhi->frequency);
 326         afhi->bitrate = pfad->map_bytes * 8 / afhi->seconds_total / 1024;
 327         chunk_time = (double)pfad->blocksize / afhi->frequency;
 328         afhi->chunk_tv.tv_sec = chunk_time;
 329         chunk_time *= 1000 * 1000;
 330         chunk_time -= afhi->chunk_tv.tv_sec * 1000 * 1000;
 331         afhi->chunk_tv.tv_usec = chunk_time;
 332         return 1;
 333 }
 334
 335 static const char* flac_suffixes[] = {"flac", NULL};
 336
 337 /**
 338  * The init function of the flac audio format handler.
 339  *
 340  * \param afh pointer to the struct to initialize
 341  */
 342 void flac_afh_init(struct audio_format_handler *afh)
 343 {
 344         afh->get_file_info = flac_get_file_info,
 345         afh->suffixes = flac_suffixes;
 346 }