afh_common.c

   1 /* Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file afh_common.c Common audio format handler functions. */
   4
   5 #include <sys/mman.h> /* mmap */
   6 #include <sys/types.h>
   7 #include <regex.h>
   8
   9 #include "para.h"
  10 #include "error.h"
  11 #include "string.h"
  12 #include "afh.h"
  13
  14 /** The list of all status items */
  15 const char *status_item_list[] = {STATUS_ITEMS};
  16
  17 /**
  18  * For each audio file the number of its audio format is stored in the
  19  * database. Therefore this list, in particular its order, is part of the ABI.
  20  * So it's only OK to append new audio formats. All audio formats are listed
  21  * here, regardless of whether the audio format handler is compiled in.
  22  */
  23 #define ALL_AUDIO_FORMATS \
  24         AUDIO_FORMAT(mp3) \
  25         AUDIO_FORMAT(ogg) \
  26         AUDIO_FORMAT(aac) \
  27         AUDIO_FORMAT(wma) \
  28         AUDIO_FORMAT(spx) \
  29         AUDIO_FORMAT(flac) \
  30         AUDIO_FORMAT(opus) \
  31
  32 /** \cond audio_format_handler */
  33 #define AUDIO_FORMAT(_fmt) #_fmt,
  34 static const char * const audio_format_names[] = {ALL_AUDIO_FORMATS};
  35 #undef AUDIO_FORMAT
  36 /* Weak declarations must be public. */
  37 #define AUDIO_FORMAT(_fmt) \
  38         struct audio_format_handler _fmt ## _afh __attribute__ ((weak)) \
  39         = {.get_file_info = NULL};
  40 ALL_AUDIO_FORMATS
  41 #undef AUDIO_FORMAT
  42 #define AUDIO_FORMAT(_fmt) & _fmt ## _afh,
  43 static struct audio_format_handler *afl[] = {ALL_AUDIO_FORMATS};
  44 #undef AUDIO_FORMAT
  45 #define NUM_AUDIO_FORMATS (ARRAY_SIZE(afl))
  46 /** \endcond audio_format_handler */
  47
  48 /**
  49  * Get the name of the given audio format.
  50  *
  51  * \param i The audio format number.
  52  *
  53  * \return This returns a pointer to statically allocated memory so it
  54  * must not be freed by the caller.
  55  */
  56 const char *audio_format_name(int i)
  57 {
  58         if (i < 0 || i >= NUM_AUDIO_FORMATS)
  59                 return "???";
  60         return audio_format_names[i];
  61 }
  62
  63 static inline int next_audio_format(int format)
  64 {
  65         for (;;) {
  66                 format++;
  67                 if (format >= NUM_AUDIO_FORMATS)
  68                         return format;
  69                 if (afl[format]->get_file_info)
  70                         return format;
  71         }
  72 }
  73
  74 /** Iterate over each supported audio format. */
  75 #define FOR_EACH_AUDIO_FORMAT(i) \
  76         for (i = 0; i < NUM_AUDIO_FORMATS; i = next_audio_format(i))
  77
  78 /**
  79  * Tell whether an audio format handler provides chunk tables.
  80  *
  81  * Each audio format handler either provides a chunk table or supports dynamic
  82  * chunks.
  83  *
  84  * \param audio_format_id Offset in the afl array.
  85  *
  86  * \return True if dynamic chunks are supported, false if the audio format
  87  * handler provides chunk tables.
  88  */
  89 bool afh_supports_dynamic_chunks(int audio_format_id)
  90 {
  91         return afl[audio_format_id]->get_chunk;
  92 }
  93
  94 /**
  95  * Guess the audio format judging from filename.
  96  *
  97  * \param name The filename.
  98  *
  99  * \return This function returns \p -E_AUDIO_FORMAT if it has no idea what kind
 100  * of audio file this might be. Otherwise the (non-negative) number of the
 101  * audio format is returned.
 102  */
 103 int guess_audio_format(const char *name)
 104 {
 105         int i,j, len = strlen(name);
 106
 107         FOR_EACH_AUDIO_FORMAT(i) {
 108                 for (j = 0; afl[i]->suffixes[j]; j++) {
 109                         const char *p = afl[i]->suffixes[j];
 110                         int plen = strlen(p);
 111                         if (len < plen + 1)
 112                                 continue;
 113                         if (name[len - plen - 1] != '.')
 114                                 continue;
 115                         if (strcasecmp(name + len - plen, p))
 116                                 continue;
 117 //                      PARA_DEBUG_LOG("might be %s\n", audio_format_name(i));
 118                         return i;
 119                 }
 120         }
 121         return -E_AUDIO_FORMAT;
 122 }
 123
 124 static int get_file_info(int format, const char *path, char *data,
 125                 size_t size, int fd, struct afh_info *afhi)
 126 {
 127         int ret;
 128         const char *fmt = audio_format_name(format);
 129
 130         memset(afhi, 0, sizeof(*afhi));
 131         ret = afl[format]->get_file_info(data, size, fd, afhi);
 132         if (ret < 0) {
 133                 PARA_WARNING_LOG("%s: %s format not detected: %s\n",
 134                         path, fmt, para_strerror(-ret));
 135                 return ret;
 136         }
 137         PARA_NOTICE_LOG("%s: detected %s format\n", path, fmt);
 138         return format;
 139 }
 140
 141 /**
 142  * Call get_file_info() to obtain an afhi structure.
 143  *
 144  * \param path The full path of the audio file.
 145  * \param data Pointer to the contents of the (mapped) file.
 146  * \param size The file size in bytes.
 147  * \param fd The open file descriptor.
 148  * \param afhi Result pointer.
 149  *
 150  * \return The number of the audio format on success, \p -E_AUDIO_FORMAT if no
 151  * compiled in audio format handler is able to handler the file.
 152  *
 153  * This function tries to find an audio format handler that can interpret the
 154  * file given by \a data and \a size.
 155  *
 156  * It first tries to determine the audio format from the filename given by \a
 157  * path. If this doesn't work, all other audio format handlers are tried until
 158  * one is found that can handle the file.
 159  */
 160 int compute_afhi(const char *path, char *data, size_t size, int fd,
 161                 struct afh_info *afhi)
 162 {
 163         int ret, i, format;
 164
 165         format = guess_audio_format(path);
 166         if (format >= 0) {
 167                 ret = get_file_info(format, path, data, size, fd, afhi);
 168                 if (ret >= 0)
 169                         goto success;
 170         }
 171         FOR_EACH_AUDIO_FORMAT(i) {
 172                 if (i == format) /* we already tried this one to no avail */
 173                         continue;
 174                 ret = get_file_info(i, path, data, size, fd, afhi);
 175                 if (ret >= 0)
 176                         goto success;
 177         }
 178         return -E_AUDIO_FORMAT;
 179 success:
 180         if (!afhi->techinfo)
 181                 afhi->techinfo = para_strdup(NULL);
 182         if (!afhi->tags.artist)
 183                 afhi->tags.artist = para_strdup(NULL);
 184         if (!afhi->tags.title)
 185                 afhi->tags.title = para_strdup(NULL);
 186         if (!afhi->tags.year)
 187                 afhi->tags.year = para_strdup(NULL);
 188         if (!afhi->tags.album)
 189                 afhi->tags.album = para_strdup(NULL);
 190         if (!afhi->tags.comment)
 191                 afhi->tags.comment = para_strdup(NULL);
 192         PARA_DEBUG_LOG("techinfo: %s\n", afhi->techinfo);
 193         PARA_DEBUG_LOG("artist: %s\n", afhi->tags.artist);
 194         PARA_DEBUG_LOG("title: %s\n", afhi->tags.title);
 195         PARA_DEBUG_LOG("year: %s\n", afhi->tags.year);
 196         PARA_DEBUG_LOG("album: %s\n", afhi->tags.album);
 197         PARA_DEBUG_LOG("comment: %s\n", afhi->tags.comment);
 198         return ret;
 199 }
 200
 201 /**
 202  * Deallocate the contents of an afh_info structure.
 203  *
 204  * \param afhi The structure to clear.
 205  *
 206  * This only frees the memory the various pointer fields of \a afhi point to.
 207  * It does *not* free \a afhi itself.
 208  */
 209 void clear_afhi(struct afh_info *afhi)
 210 {
 211         if (!afhi)
 212                 return;
 213         free(afhi->chunk_table);
 214         free(afhi->techinfo);
 215         free(afhi->tags.artist);
 216         free(afhi->tags.title);
 217         free(afhi->tags.year);
 218         free(afhi->tags.album);
 219         free(afhi->tags.comment);
 220 }
 221
 222 static inline uint32_t get_chunk_len(long unsigned chunk_num,
 223                 const struct afh_info *afhi)
 224 {
 225         return afhi->chunk_table[chunk_num + 1] - afhi->chunk_table[chunk_num];
 226 }
 227
 228 /**
 229  * Get one chunk of audio data.
 230  *
 231  * This implicitly calls the ->open method of the audio format handler at the
 232  * first call.
 233  *
 234  * \param chunk_num The number of the chunk to get.
 235  * \param afhi Describes the audio file.
 236  * \param audio_format_id Determines the afh.
 237  * \param map The memory mapped audio file.
 238  * \param mapsize Passed to the afh's ->open() method.
 239  * \param buf Result pointer.
 240  * \param len The length of the chunk in bytes.
 241  * \param afh_context Value/result, determines whether ->open() is called.
 242  *
 243  * Upon return, \a buf will point so memory inside \a map. The returned buffer
 244  * must therefore not be freed by the caller.
 245  *
 246  * \return Standard.
 247  */
 248 __must_check int afh_get_chunk(long unsigned chunk_num, struct afh_info *afhi,
 249                 uint8_t audio_format_id, const void *map, size_t mapsize,
 250                 const char **buf, uint32_t *len, void **afh_context)
 251 {
 252         struct audio_format_handler *afh = afl[audio_format_id];
 253
 254         if (afh_supports_dynamic_chunks(audio_format_id)) {
 255                 int ret;
 256
 257                 if (!*afh_context) {
 258                         ret = afh->open(map, mapsize, afh_context);
 259                         if (ret < 0)
 260                                 return ret;
 261                 }
 262                 ret = afh->get_chunk(chunk_num, *afh_context,
 263                         buf, len);
 264                 if (ret < 0) {
 265                         afh->close(*afh_context);
 266                         *afh_context = NULL;
 267                 }
 268                 return ret;
 269         } else {
 270                 size_t pos = afhi->chunk_table[chunk_num];
 271                 *buf = map + pos;
 272                 *len = get_chunk_len(chunk_num, afhi);
 273                 return 0;
 274         }
 275 }
 276
 277 /**
 278  * Deallocate resources allocated due to dynamic chunk handling.
 279  *
 280  * This function should be called if afh_get_chunk() was called at least once.
 281  * It is OK to call it even for audio formats which do not support dynamic
 282  * chunks, in which case the function does nothing.
 283  *
 284  * \param afh_context As returned from the ->open method of the afh.
 285  * \param audio_format_id Determines the afh.
 286  */
 287 void afh_close(void *afh_context, uint8_t audio_format_id)
 288 {
 289         struct audio_format_handler *afh = afl[audio_format_id];
 290
 291         if (!afh_supports_dynamic_chunks(audio_format_id))
 292                 return;
 293         if (!afh->close)
 294                 return;
 295         if (!afh_context)
 296                 return;
 297         afh->close(afh_context);
 298 }
 299
 300 /**
 301  * Find a suitable start chunk.
 302  *
 303  * \param approx_chunk_num Upper bound for the chunk number to return.
 304  * \param afhi Needed for the chunk table.
 305  * \param audio_format_id Determines the afh.
 306  *
 307  * \return For audio format handlers which support dynamic chunks, the function
 308  * returns the given chunk number. Otherwise it returns the first non-empty
 309  * chunk <= \a approx_chunk_num.
 310  *
 311  * \sa \ref afh_get_chunk().
 312  */
 313 int32_t afh_get_start_chunk(int32_t approx_chunk_num,
 314                 const struct afh_info *afhi, uint8_t audio_format_id)
 315 {
 316         int32_t k;
 317
 318         if (afh_supports_dynamic_chunks(audio_format_id))
 319                 return approx_chunk_num;
 320
 321         for (k = PARA_MAX(0, approx_chunk_num); k >= 0; k--)
 322                 if (get_chunk_len(k, afhi) > 0)
 323                         return k;
 324         return 0;
 325 }
 326
 327 /**
 328  * Get the header of an audio file.
 329  *
 330  * \param afhi The audio file handler data describing the file.
 331  * \param audio_format_id Determines the audio format handler.
 332  * \param map The data of the audio file.
 333  * \param mapsize The amount of bytes of the mmapped audio file.
 334  * \param buf The length of the header is stored here.
 335  * \param len Points to a buffer containing the header on return.
 336  *
 337  * This function sets \a buf to \p NULL and \a len to zero if \a map or \a
 338  * afhi is \p NULL, or if the current audio format does not need special
 339  * header treatment.
 340  *
 341  * Otherwise, it is checked whether the audio format handler given by
 342  * \a audio_format_id defines a ->get_header() method. If it does, this
 343  * method is called to obtain the header. If ->get_header() is \p NULL,
 344  * a reference to the first chunk of the audio file is returned.
 345  *
 346  * Once the header is no longer needed, the caller must call \ref
 347  * afh_free_header() to free the resources allocated by this function.
 348  */
 349 void afh_get_header(struct afh_info *afhi, uint8_t audio_format_id,
 350                 void *map, size_t mapsize, char **buf, size_t *len)
 351 {
 352         struct audio_format_handler *afh = afl[audio_format_id];
 353
 354         if (!map || !afhi || !afhi->header_len) {
 355                 *buf = NULL;
 356                 *len = 0;
 357                 return;
 358         }
 359         if (!afh->get_header) {
 360                 *len = afhi->header_len;
 361                 *buf = map;
 362                 return;
 363         }
 364         afh->get_header(map, mapsize, buf, len);
 365 }
 366
 367 /**
 368  * Deallocate any resources obtained from afh_get_header().
 369  *
 370  * \param header_buf Pointer obtained via afh_get_header().
 371  * \param audio_format_id Determines the audio format handler.
 372  */
 373 void afh_free_header(char *header_buf, uint8_t audio_format_id)
 374 {
 375         struct audio_format_handler *afh = afl[audio_format_id];
 376
 377         if (afh->get_header)
 378                 free(header_buf);
 379 }
 380
 381 /**
 382  * Pretty-print the contents of a struct afh_info into a buffer.
 383  *
 384  * \param audio_format_num The audio format number.
 385  * \param afhi Pointer to the structure that contains the information.
 386  * \param result Pretty-printed ahfi is here after the call.
 387  *
 388  * The \a result buffer is dynamically allocated and should be freed by the
 389  * caller.
 390  *
 391  * \return The number of bytes. This function never fails.
 392  */
 393 unsigned afh_get_afhi_txt(int audio_format_num, struct afh_info *afhi, char **result)
 394 {
 395         return xasprintf(result, "%s: %dkbit/s\n" /* bitrate */
 396                 "%s: %s\n" /* format */
 397                 "%s: %dHz\n" /* frequency */
 398                 "%s: %d\n" /* channels */
 399                 "%s: %" PRIu32 "\n" /* seconds total */
 400                 "%s: %lu: %lu\n" /* chunk time */
 401                 "%s: %" PRIu32 "\n" /* num chunks */
 402                 "%s: %" PRIu32 "\n" /* max chunk size */
 403                 "%s: %s\n" /* techinfo */
 404                 "%s: %s\n" /* artist */
 405                 "%s: %s\n" /* title */
 406                 "%s: %s\n" /* year */
 407                 "%s: %s\n" /* album */
 408                 "%s: %s\n", /* comment */
 409                 status_item_list[SI_bitrate], afhi->bitrate,
 410                 status_item_list[SI_format], audio_format_name(audio_format_num),
 411                 status_item_list[SI_frequency], afhi->frequency,
 412                 status_item_list[SI_channels], afhi->channels,
 413                 status_item_list[SI_seconds_total], afhi->seconds_total,
 414                 status_item_list[SI_chunk_time], (long unsigned)afhi->chunk_tv.tv_sec,
 415                         (long unsigned)afhi->chunk_tv.tv_usec,
 416                 status_item_list[SI_num_chunks], afhi->chunks_total,
 417                 status_item_list[SI_max_chunk_size], afhi->max_chunk_size,
 418                 status_item_list[SI_techinfo], afhi->techinfo? afhi->techinfo : "",
 419                 status_item_list[SI_artist], afhi->tags.artist? afhi->tags.artist : "",
 420                 status_item_list[SI_title], afhi->tags.title? afhi->tags.title : "",
 421                 status_item_list[SI_year], afhi->tags.year? afhi->tags.year : "",
 422                 status_item_list[SI_album], afhi->tags.album? afhi->tags.album : "",
 423                 status_item_list[SI_comment], afhi->tags.comment? afhi->tags.comment : ""
 424         );
 425 }
 426
 427 /**
 428  * Determine the maximal chunk size by investigating the chunk table.
 429  *
 430  * \param afhi Value/result.
 431  *
 432  * This function iterates over the chunk table and sets ->max_chunk_size
 433  * accordingly. The function exists only for backward compatibility since as of
 434  * version 0.6.0, para_server stores the maximal chunk size in its database.
 435  * This function is only called if the database value is zero, indicating that
 436  * the file was added by an older server version.
 437  */
 438 void set_max_chunk_size(struct afh_info *afhi)
 439 {
 440         uint32_t n, max = 0, old = 0;
 441
 442         for (n = 0; n <= afhi->chunks_total; n++) {
 443                 uint32_t val = afhi->chunk_table[n];
 444                 /*
 445                  * If the first chunk is the header, do not consider it for the
 446                  * calculation of the largest chunk size.
 447                  */
 448                 if (n == 0 || (n == 1 && afhi->header_len > 0)) {
 449                         old = val;
 450                         continue;
 451                 }
 452                 max = PARA_MAX(max, val - old);
 453                 old = val;
 454         }
 455         afhi->max_chunk_size = max;
 456 }
 457
 458 /**
 459  * Create a copy of the given file with altered meta tags.
 460  *
 461  * \param audio_format_id Specifies the audio format.
 462  * \param map The (read-only) memory map of the input file.
 463  * \param mapsize The size of the input file in bytes.
 464  * \param tags The new tags.
 465  * \param output_fd Altered file is created using this file descriptor.
 466  * \param filename The name of the temporary output file.
 467  *
 468  * This calls the ->rewrite_tags method of the audio format handler associated
 469  * with \a audio_format_id to create a copy of the memory-mapped file given
 470  * by \a map and \a mapsize, but with altered tags according to \a tags. If
 471  * the audio format handler for \a audio_format_id lacks this optional method,
 472  * the function returns (the paraslash error code of) \p ENOTSUP.
 473  *
 474  * \return Standard.
 475  */
 476 int afh_rewrite_tags(int audio_format_id, void *map, size_t mapsize,
 477                 struct taginfo *tags, int output_fd, const char *filename)
 478 {
 479         struct audio_format_handler *afh = afl[audio_format_id];
 480
 481         if (!afh->rewrite_tags)
 482                 return -ERRNO_TO_PARA_ERROR(ENOTSUP);
 483         return afh->rewrite_tags(map, mapsize, tags, output_fd, filename);
 484 }