afh: Get rid of dummy entry at the end of afl[].
[paraslash.git] / 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 typedef void afh_init_func(struct audio_format_handler *);
15
16 /*
17 * Declaration of the audio format handler init functions.
18 *
19 * These symbols are referenced in the afl array below.
20 *
21 * Most audio format handlers depend on an external library and are not
22 * compiled in if the library is not installed. Hence it is well possible that
23 * not all of these functions are defined. It does not hurt to declare them
24 * anyway, and this avoids another set of ifdefs.
25 */
26 extern afh_init_func mp3_afh_init, ogg_afh_init, aac_afh_init, wma_afh_init,
27 spx_afh_init, flac_afh_init, opus_afh_init;
28
29 /** The list of all status items */
30 const char *status_item_list[] = {STATUS_ITEMS};
31
32 /**
33 * The list of supported audio formats.
34 *
35 * We always define the full array of audio formats even if some audio formats
36 * were not compiled in. This is because for each audio file the number of its
37 * audio format is stored in the database. We don't want these numbers to become
38 * stale just because the user installed a new version of paraslash that
39 * supports a different set of audio formats.
40 *
41 * It can still be easily detected whether an audio format is compiled in by
42 * checking if the init function pointer is not \p NULL.
43 */
44 static struct audio_format_handler afl[] = {
45 {
46 .name = "mp3",
47 .init = mp3_afh_init,
48 },
49 {
50 .name = "ogg",
51 #if defined(HAVE_OGG) && defined(HAVE_VORBIS)
52 .init = ogg_afh_init,
53 #endif
54 },
55 {
56 .name = "aac",
57 #if defined(HAVE_FAAD)
58 .init = aac_afh_init,
59 #endif
60 },
61 {
62 .name = "wma",
63 .init = wma_afh_init,
64 },
65 {
66 .name = "spx",
67 #if defined(HAVE_OGG) && defined(HAVE_SPEEX)
68 .init = spx_afh_init,
69 #endif
70 },
71 {
72 .name = "flac",
73 #if defined(HAVE_OGG) && defined(HAVE_FLAC)
74 .init = flac_afh_init,
75 #endif
76 },
77 {
78 .name = "opus",
79 #if defined(HAVE_OGG) && defined(HAVE_OPUS)
80 .init = opus_afh_init,
81 #endif
82 },
83 };
84
85 /** This includes audio formats not compiled in. */
86 #define NUM_AUDIO_FORMATS (ARRAY_SIZE(afl))
87
88 /**
89 * Get the name of the given audio format.
90 *
91 * \param i The audio format number.
92 *
93 * \return This returns a pointer to statically allocated memory so it
94 * must not be freed by the caller.
95 */
96 const char *audio_format_name(int i)
97 {
98 if (i < 0 || i >= NUM_AUDIO_FORMATS)
99 return "???";
100 return afl[i].name;
101 }
102
103 static inline int next_audio_format(int format)
104 {
105 for (;;) {
106 format++;
107 if (format >= NUM_AUDIO_FORMATS)
108 return format;
109 if (afl[format].init)
110 return format;
111 }
112 }
113
114 /** Iterate over each supported audio format. */
115 #define FOR_EACH_AUDIO_FORMAT(i) \
116 for (i = 0; i < NUM_AUDIO_FORMATS; i = next_audio_format(i))
117
118 /**
119 * Call the init function of each supported audio format handler.
120 */
121 void afh_init(void)
122 {
123 int i;
124
125 PARA_NOTICE_LOG("supported audio formats: %s\n", AUDIO_FORMAT_HANDLERS);
126 FOR_EACH_AUDIO_FORMAT(i) {
127 PARA_INFO_LOG("initializing %s handler\n",
128 audio_format_name(i));
129 afl[i].init(&afl[i]);
130 }
131 }
132
133 /**
134 * Tell whether an audio format handler provides chunk tables.
135 *
136 * Each audio format handler either provides a chunk table or supports dynamic
137 * chunks.
138 *
139 * \param audio_format_id Offset in the afl array.
140 *
141 * \return True if dynamic chunks are supported, false if the audio format
142 * handler provides chunk tables.
143 */
144 bool afh_supports_dynamic_chunks(int audio_format_id)
145 {
146 return afl[audio_format_id].get_chunk;
147 }
148
149 /**
150 * Guess the audio format judging from filename.
151 *
152 * \param name The filename.
153 *
154 * \return This function returns \p -E_AUDIO_FORMAT if it has no idea what kind
155 * of audio file this might be. Otherwise the (non-negative) number of the
156 * audio format is returned.
157 */
158 int guess_audio_format(const char *name)
159 {
160 int i,j, len = strlen(name);
161
162 FOR_EACH_AUDIO_FORMAT(i) {
163 for (j = 0; afl[i].suffixes[j]; j++) {
164 const char *p = afl[i].suffixes[j];
165 int plen = strlen(p);
166 if (len < plen + 1)
167 continue;
168 if (name[len - plen - 1] != '.')
169 continue;
170 if (strcasecmp(name + len - plen, p))
171 continue;
172 // PARA_DEBUG_LOG("might be %s\n", audio_format_name(i));
173 return i;
174 }
175 }
176 return -E_AUDIO_FORMAT;
177 }
178
179 static int get_file_info(int format, const char *path, char *data,
180 size_t size, int fd, struct afh_info *afhi)
181 {
182 int ret;
183 const char *fmt = audio_format_name(format);
184
185 memset(afhi, 0, sizeof(*afhi));
186 ret = afl[format].get_file_info(data, size, fd, afhi);
187 if (ret < 0) {
188 PARA_WARNING_LOG("%s: %s format not detected: %s\n",
189 path, fmt, para_strerror(-ret));
190 return ret;
191 }
192 PARA_NOTICE_LOG("%s: detected %s format\n", path, fmt);
193 return format;
194 }
195
196 /**
197 * Call get_file_info() to obtain an afhi structure.
198 *
199 * \param path The full path of the audio file.
200 * \param data Pointer to the contents of the (mapped) file.
201 * \param size The file size in bytes.
202 * \param fd The open file descriptor.
203 * \param afhi Result pointer.
204 *
205 * \return The number of the audio format on success, \p -E_AUDIO_FORMAT if no
206 * compiled in audio format handler is able to handler the file.
207 *
208 * This function tries to find an audio format handler that can interpret the
209 * file given by \a data and \a size.
210 *
211 * It first tries to determine the audio format from the filename given by \a
212 * path. If this doesn't work, all other audio format handlers are tried until
213 * one is found that can handle the file.
214 */
215 int compute_afhi(const char *path, char *data, size_t size, int fd,
216 struct afh_info *afhi)
217 {
218 int ret, i, format;
219
220 format = guess_audio_format(path);
221 if (format >= 0) {
222 ret = get_file_info(format, path, data, size, fd, afhi);
223 if (ret >= 0)
224 goto success;
225 }
226 FOR_EACH_AUDIO_FORMAT(i) {
227 if (i == format) /* we already tried this one to no avail */
228 continue;
229 ret = get_file_info(i, path, data, size, fd, afhi);
230 if (ret >= 0)
231 goto success;
232 }
233 return -E_AUDIO_FORMAT;
234 success:
235 if (!afhi->techinfo)
236 afhi->techinfo = para_strdup(NULL);
237 if (!afhi->tags.artist)
238 afhi->tags.artist = para_strdup(NULL);
239 if (!afhi->tags.title)
240 afhi->tags.title = para_strdup(NULL);
241 if (!afhi->tags.year)
242 afhi->tags.year = para_strdup(NULL);
243 if (!afhi->tags.album)
244 afhi->tags.album = para_strdup(NULL);
245 if (!afhi->tags.comment)
246 afhi->tags.comment = para_strdup(NULL);
247 PARA_DEBUG_LOG("techinfo: %s\n", afhi->techinfo);
248 PARA_DEBUG_LOG("artist: %s\n", afhi->tags.artist);
249 PARA_DEBUG_LOG("title: %s\n", afhi->tags.title);
250 PARA_DEBUG_LOG("year: %s\n", afhi->tags.year);
251 PARA_DEBUG_LOG("album: %s\n", afhi->tags.album);
252 PARA_DEBUG_LOG("comment: %s\n", afhi->tags.comment);
253 return ret;
254 }
255
256 /**
257 * Deallocate the contents of an afh_info structure.
258 *
259 * \param afhi The structure to clear.
260 *
261 * This only frees the memory the various pointer fields of \a afhi point to.
262 * It does *not* free \a afhi itself.
263 */
264 void clear_afhi(struct afh_info *afhi)
265 {
266 if (!afhi)
267 return;
268 free(afhi->chunk_table);
269 free(afhi->techinfo);
270 free(afhi->tags.artist);
271 free(afhi->tags.title);
272 free(afhi->tags.year);
273 free(afhi->tags.album);
274 free(afhi->tags.comment);
275 }
276
277 static inline size_t get_chunk_len(long unsigned chunk_num,
278 const struct afh_info *afhi)
279 {
280 return afhi->chunk_table[chunk_num + 1] - afhi->chunk_table[chunk_num];
281 }
282
283 /**
284 * Get one chunk of audio data.
285 *
286 * This implicitly calls the ->open method of the audio format handler at the
287 * first call.
288 *
289 * \param chunk_num The number of the chunk to get.
290 * \param afhi Describes the audio file.
291 * \param audio_format_id Determines the afh.
292 * \param map The memory mapped audio file.
293 * \param mapsize Passed to the afh's ->open() method.
294 * \param buf Result pointer.
295 * \param len The length of the chunk in bytes.
296 * \param afh_context Value/result, determines whether ->open() is called.
297 *
298 * Upon return, \a buf will point so memory inside \a map. The returned buffer
299 * must therefore not be freed by the caller.
300 *
301 * \return Standard.
302 */
303 __must_check int afh_get_chunk(long unsigned chunk_num, struct afh_info *afhi,
304 uint8_t audio_format_id, const void *map, size_t mapsize,
305 const char **buf, size_t *len, void **afh_context)
306 {
307 struct audio_format_handler *afh = afl + audio_format_id;
308
309 if (afh_supports_dynamic_chunks(audio_format_id)) {
310 int ret;
311
312 if (!*afh_context) {
313 ret = afh->open(map, mapsize, afh_context);
314 if (ret < 0)
315 return ret;
316 }
317 ret = afh->get_chunk(chunk_num, *afh_context,
318 buf, len);
319 if (ret < 0) {
320 afh->close(*afh_context);
321 *afh_context = NULL;
322 }
323 return ret;
324 } else {
325 size_t pos = afhi->chunk_table[chunk_num];
326 *buf = map + pos;
327 *len = get_chunk_len(chunk_num, afhi);
328 return 0;
329 }
330 }
331
332 /**
333 * Deallocate resources allocated due to dynamic chunk handling.
334 *
335 * This function should be called if afh_get_chunk() was called at least once.
336 * It is OK to call it even for audio formats which do not support dynamic
337 * chunks, in which case the function does nothing.
338 *
339 * \param afh_context As returned from the ->open method of the afh.
340 * \param audio_format_id Determines the afh.
341 */
342 void afh_close(void *afh_context, uint8_t audio_format_id)
343 {
344 struct audio_format_handler *afh = afl + audio_format_id;
345
346 if (!afh_supports_dynamic_chunks(audio_format_id))
347 return;
348 if (!afh->close)
349 return;
350 if (!afh_context)
351 return;
352 afh->close(afh_context);
353 }
354
355 /**
356 * Find a suitable start chunk.
357 *
358 * \param approx_chunk_num Upper bound for the chunk number to return.
359 * \param afhi Needed for the chunk table.
360 * \param audio_format_id Determines the afh.
361 *
362 * \return For audio format handlers which support dynamic chunks, the function
363 * returns the given chunk number. Otherwise it returns the first non-empty
364 * chunk <= \a approx_chunk_num.
365 *
366 * \sa \ref afh_get_chunk().
367 */
368 int32_t afh_get_start_chunk(int32_t approx_chunk_num,
369 const struct afh_info *afhi, uint8_t audio_format_id)
370 {
371 int32_t k;
372
373 if (afh_supports_dynamic_chunks(audio_format_id))
374 return approx_chunk_num;
375
376 for (k = PARA_MAX(0, approx_chunk_num); k >= 0; k--)
377 if (get_chunk_len(k, afhi) > 0)
378 return k;
379 return 0;
380 }
381
382 /**
383 * Get the header of an audio file.
384 *
385 * \param afhi The audio file handler data describing the file.
386 * \param audio_format_id Determines the audio format handler.
387 * \param map The data of the audio file.
388 * \param mapsize The amount of bytes of the mmapped audio file.
389 * \param buf The length of the header is stored here.
390 * \param len Points to a buffer containing the header on return.
391 *
392 * This function sets \a buf to \p NULL and \a len to zero if \a map or \a
393 * afhi is \p NULL, or if the current audio format does not need special
394 * header treatment.
395 *
396 * Otherwise, it is checked whether the audio format handler given by
397 * \a audio_format_id defines a ->get_header() method. If it does, this
398 * method is called to obtain the header. If ->get_header() is \p NULL,
399 * a reference to the first chunk of the audio file is returned.
400 *
401 * Once the header is no longer needed, the caller must call \ref
402 * afh_free_header() to free the resources allocated by this function.
403 */
404 void afh_get_header(struct afh_info *afhi, uint8_t audio_format_id,
405 void *map, size_t mapsize, char **buf, size_t *len)
406 {
407 struct audio_format_handler *afh = afl + audio_format_id;
408
409 if (!map || !afhi || !afhi->header_len) {
410 *buf = NULL;
411 *len = 0;
412 return;
413 }
414 if (!afh->get_header) {
415 *len = afhi->header_len;
416 *buf = map;
417 return;
418 }
419 afh->get_header(map, mapsize, buf, len);
420 }
421
422 /**
423 * Deallocate any resources obtained from afh_get_header().
424 *
425 * \param header_buf Pointer obtained via afh_get_header().
426 * \param audio_format_id Determines the audio format handler.
427 */
428 void afh_free_header(char *header_buf, uint8_t audio_format_id)
429 {
430 struct audio_format_handler *afh = afl + audio_format_id;
431
432 if (afh->get_header)
433 free(header_buf);
434 }
435
436 /**
437 * Pretty-print the contents of a struct afh_info into a buffer.
438 *
439 * \param audio_format_num The audio format number.
440 * \param afhi Pointer to the structure that contains the information.
441 * \param result Pretty-printed ahfi is here after the call.
442 *
443 * The \a result buffer is dynamically allocated and should be freed by the
444 * caller.
445 *
446 * \return The number of bytes. This function never fails.
447 */
448 unsigned afh_get_afhi_txt(int audio_format_num, struct afh_info *afhi, char **result)
449 {
450 return xasprintf(result, "%s: %dkbit/s\n" /* bitrate */
451 "%s: %s\n" /* format */
452 "%s: %dHz\n" /* frequency */
453 "%s: %d\n" /* channels */
454 "%s: %" PRIu32 "\n" /* seconds total */
455 "%s: %lu: %lu\n" /* chunk time */
456 "%s: %" PRIu32 "\n" /* num chunks */
457 "%s: %" PRIu32 "\n" /* max chunk size */
458 "%s: %s\n" /* techinfo */
459 "%s: %s\n" /* artist */
460 "%s: %s\n" /* title */
461 "%s: %s\n" /* year */
462 "%s: %s\n" /* album */
463 "%s: %s\n", /* comment */
464 status_item_list[SI_bitrate], afhi->bitrate,
465 status_item_list[SI_format], audio_format_name(audio_format_num),
466 status_item_list[SI_frequency], afhi->frequency,
467 status_item_list[SI_channels], afhi->channels,
468 status_item_list[SI_seconds_total], afhi->seconds_total,
469 status_item_list[SI_chunk_time], (long unsigned)afhi->chunk_tv.tv_sec,
470 (long unsigned)afhi->chunk_tv.tv_usec,
471 status_item_list[SI_num_chunks], afhi->chunks_total,
472 status_item_list[SI_max_chunk_size], afhi->max_chunk_size,
473 status_item_list[SI_techinfo], afhi->techinfo? afhi->techinfo : "",
474 status_item_list[SI_artist], afhi->tags.artist? afhi->tags.artist : "",
475 status_item_list[SI_title], afhi->tags.title? afhi->tags.title : "",
476 status_item_list[SI_year], afhi->tags.year? afhi->tags.year : "",
477 status_item_list[SI_album], afhi->tags.album? afhi->tags.album : "",
478 status_item_list[SI_comment], afhi->tags.comment? afhi->tags.comment : ""
479 );
480 }
481
482 /**
483 * Determine the maximal chunk size by investigating the chunk table.
484 *
485 * \param afhi Value/result.
486 *
487 * This function iterates over the chunk table and sets ->max_chunk_size
488 * accordingly. The function exists only for backward compatibility since as of
489 * version 0.6.0, para_server stores the maximal chunk size in its database.
490 * This function is only called if the database value is zero, indicating that
491 * the file was added by an older server version.
492 */
493 void set_max_chunk_size(struct afh_info *afhi)
494 {
495 uint32_t n, max = 0, old = 0;
496
497 for (n = 0; n <= afhi->chunks_total; n++) {
498 uint32_t val = afhi->chunk_table[n];
499 /*
500 * If the first chunk is the header, do not consider it for the
501 * calculation of the largest chunk size.
502 */
503 if (n == 0 || (n == 1 && afhi->header_len > 0)) {
504 old = val;
505 continue;
506 }
507 max = PARA_MAX(max, val - old);
508 old = val;
509 }
510 afhi->max_chunk_size = max;
511 }
512
513 /**
514 * Create a copy of the given file with altered meta tags.
515 *
516 * \param audio_format_id Specifies the audio format.
517 * \param map The (read-only) memory map of the input file.
518 * \param mapsize The size of the input file in bytes.
519 * \param tags The new tags.
520 * \param output_fd Altered file is created using this file descriptor.
521 * \param filename The name of the temporary output file.
522 *
523 * This calls the ->rewrite_tags method of the audio format handler associated
524 * with \a audio_format_id to create a copy of the memory-mapped file given
525 * by \a map and \a mapsize, but with altered tags according to \a tags. If
526 * the audio format handler for \a audio_format_id lacks this optional method,
527 * the function returns (the paraslash error code of) \p ENOTSUP.
528 *
529 * \return Standard.
530 */
531 int afh_rewrite_tags(int audio_format_id, void *map, size_t mapsize,
532 struct taginfo *tags, int output_fd, const char *filename)
533 {
534 struct audio_format_handler *afh = afl + audio_format_id;
535
536 if (!afh->rewrite_tags)
537 return -ERRNO_TO_PARA_ERROR(ENOTSUP);
538 return afh->rewrite_tags(map, mapsize, tags, output_fd, filename);
539 }