6feb7c3565dc6ed1f9023ba4eb6ad6b19bcadd48
[paraslash.git] / afh_common.c
1 /*
2 * Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file afh_common.c Common audio format handler functions. */
8
9 #include <sys/mman.h> /* mmap */
10 #include <sys/types.h>
11 #include <regex.h>
12
13 #include "para.h"
14 #include "error.h"
15 #include "string.h"
16 #include "afh.h"
17
18 typedef void afh_init_func(struct audio_format_handler *);
19 /* It does not hurt to declare init functions which are not available. */
20 extern afh_init_func mp3_init, ogg_init, aac_afh_init, wma_afh_init,
21 spx_afh_init, flac_afh_init, opus_afh_init;
22
23 /** The list of all status items */
24 const char *status_item_list[] = {STATUS_ITEM_ARRAY};
25
26 /**
27 * The list of supported audio formats.
28 *
29 * We always define the full array of audio formats even if some audio formats
30 * were not compiled in. This is because for each audio file the number of its
31 * audio format is stored in the database. We don't want that numbers to become
32 * stale just because the user installed a new version of paraslash that
33 * supports a different set of audio formats.
34 *
35 * It can still be easily detected whether an audio format is compiled in by
36 * checking if the init function pointer is not \p NULL.
37 */
38 static struct audio_format_handler afl[] = {
39 {
40 .name = "mp3",
41 .init = mp3_init,
42 },
43 {
44 .name = "ogg",
45 #if defined(HAVE_OGG) && defined(HAVE_VORBIS)
46 .init = ogg_init,
47 #endif
48 },
49 {
50 .name = "aac",
51 #if defined(HAVE_FAAD)
52 .init = aac_afh_init,
53 #endif
54 },
55 {
56 .name = "wma",
57 .init = wma_afh_init,
58 },
59 {
60 .name = "spx",
61 #if defined(HAVE_OGG) && defined(HAVE_SPEEX)
62 .init = spx_afh_init,
63 #endif
64 },
65 {
66 .name = "flac",
67 #if defined(HAVE_OGG) && defined(HAVE_FLAC)
68 .init = flac_afh_init,
69 #endif
70 },
71 {
72 .name = "opus",
73 #if defined(HAVE_OGG) && defined(HAVE_OPUS)
74 .init = opus_afh_init,
75 #endif
76 },
77 {
78 .name = NULL,
79 }
80 };
81
82 static inline int next_audio_format(int format)
83 {
84 for (;;) {
85 if (!afl[format].name)
86 return format;
87 format++;
88 if (afl[format].init)
89 return format;
90 }
91 }
92
93 /** Iterate over each supported audio format. */
94 #define FOR_EACH_AUDIO_FORMAT(i) for (i = 0; afl[i].name; i = next_audio_format(i))
95
96 /**
97 * Call the init function of each supported audio format handler.
98 */
99 void afh_init(void)
100 {
101 int i;
102
103 PARA_NOTICE_LOG("supported audio formats: %s\n", AUDIO_FORMAT_HANDLERS);
104 FOR_EACH_AUDIO_FORMAT(i) {
105 PARA_INFO_LOG("initializing %s handler\n",
106 audio_format_name(i));
107 afl[i].init(&afl[i]);
108 }
109 }
110
111 /**
112 * Tell whether an audio format handler provides chunk tables.
113 *
114 * Each audio format handler either provides a chunk table or supports dynamic
115 * chunks.
116 *
117 * \param audio_format_id Offset in the afl array.
118 *
119 * \return True if dynamic chunks are supported, false if the audio format
120 * handler provides chunk tables.
121 */
122 bool afh_supports_dynamic_chunks(int audio_format_id)
123 {
124 return afl[audio_format_id].get_chunk;
125 }
126
127 /**
128 * Guess the audio format judging from filename.
129 *
130 * \param name The filename.
131 *
132 * \return This function returns \p -E_AUDIO_FORMAT if it has no idea what kind
133 * of audio file this might be. Otherwise the (non-negative) number of the
134 * audio format is returned.
135 */
136 int guess_audio_format(const char *name)
137 {
138 int i,j, len = strlen(name);
139
140 FOR_EACH_AUDIO_FORMAT(i) {
141 for (j = 0; afl[i].suffixes[j]; j++) {
142 const char *p = afl[i].suffixes[j];
143 int plen = strlen(p);
144 if (len < plen + 1)
145 continue;
146 if (name[len - plen - 1] != '.')
147 continue;
148 if (strcasecmp(name + len - plen, p))
149 continue;
150 // PARA_DEBUG_LOG("might be %s\n", audio_format_name(i));
151 return i;
152 }
153 }
154 return -E_AUDIO_FORMAT;
155 }
156
157 /**
158 * Get the name of the given audio format.
159 *
160 * \param i The audio format number.
161 *
162 * \return This returns a pointer to statically allocated memory so it
163 * must not be freed by the caller.
164 */
165 const char *audio_format_name(int i)
166 {
167 if (i < 0 || i >= ARRAY_SIZE(afl) - 1)
168 return "???";
169 return afl[i].name;
170 }
171
172 static int get_file_info(int format, const char *path, char *data,
173 size_t size, int fd, struct afh_info *afhi)
174 {
175 int ret;
176 const char *fmt = audio_format_name(format);
177
178 memset(afhi, 0, sizeof(*afhi));
179 ret = afl[format].get_file_info(data, size, fd, afhi);
180 if (ret < 0) {
181 PARA_WARNING_LOG("%s: %s format not detected: %s\n",
182 path, fmt, para_strerror(-ret));
183 return ret;
184 }
185 PARA_NOTICE_LOG("%s: detected %s format\n", path, fmt);
186 return format;
187 }
188
189 /**
190 * Call get_file_info() to obtain an afhi structure.
191 *
192 * \param path The full path of the audio file.
193 * \param data Pointer to the contents of the (mapped) file.
194 * \param size The file size in bytes.
195 * \param fd The open file descriptor.
196 * \param afhi Result pointer.
197 *
198 * \return The number of the audio format on success, \p -E_AUDIO_FORMAT if no
199 * compiled in audio format handler is able to handler the file.
200 *
201 * This function tries to find an audio format handler that can interpret the
202 * file given by \a data and \a size.
203 *
204 * It first tries to determine the audio format from the filename given by \a
205 * path. If this doesn't work, all other audio format handlers are tried until
206 * one is found that can handle the file.
207 */
208 int compute_afhi(const char *path, char *data, size_t size, int fd,
209 struct afh_info *afhi)
210 {
211 int ret, i, format;
212
213 format = guess_audio_format(path);
214 if (format >= 0) {
215 ret = get_file_info(format, path, data, size, fd, afhi);
216 if (ret >= 0)
217 goto success;
218 }
219 FOR_EACH_AUDIO_FORMAT(i) {
220 if (i == format) /* we already tried this one to no avail */
221 continue;
222 ret = get_file_info(i, path, data, size, fd, afhi);
223 if (ret >= 0)
224 goto success;
225 }
226 return -E_AUDIO_FORMAT;
227 success:
228 if (!afhi->techinfo)
229 afhi->techinfo = para_strdup(NULL);
230 if (!afhi->tags.artist)
231 afhi->tags.artist = para_strdup(NULL);
232 if (!afhi->tags.title)
233 afhi->tags.title = para_strdup(NULL);
234 if (!afhi->tags.year)
235 afhi->tags.year = para_strdup(NULL);
236 if (!afhi->tags.album)
237 afhi->tags.album = para_strdup(NULL);
238 if (!afhi->tags.comment)
239 afhi->tags.comment = para_strdup(NULL);
240 PARA_DEBUG_LOG("techinfo: %s\n", afhi->techinfo);
241 PARA_DEBUG_LOG("artist: %s\n", afhi->tags.artist);
242 PARA_DEBUG_LOG("title: %s\n", afhi->tags.title);
243 PARA_DEBUG_LOG("year: %s\n", afhi->tags.year);
244 PARA_DEBUG_LOG("album: %s\n", afhi->tags.album);
245 PARA_DEBUG_LOG("comment: %s\n", afhi->tags.comment);
246 return ret;
247 }
248
249 /**
250 * Deallocate the contents of an afh_info structure.
251 *
252 * \param afhi The structure to clear.
253 *
254 * This only frees the memory the various pointer fields of \a afhi point to.
255 * It does *not* free \a afhi itself.
256 */
257 void clear_afhi(struct afh_info *afhi)
258 {
259 if (!afhi)
260 return;
261 free(afhi->chunk_table);
262 free(afhi->techinfo);
263 free(afhi->tags.artist);
264 free(afhi->tags.title);
265 free(afhi->tags.year);
266 free(afhi->tags.album);
267 free(afhi->tags.comment);
268 }
269
270 static inline size_t get_chunk_len(long unsigned chunk_num,
271 const struct afh_info *afhi)
272 {
273 return afhi->chunk_table[chunk_num + 1] - afhi->chunk_table[chunk_num];
274 }
275
276 /**
277 * Get one chunk of audio data.
278 *
279 * This implicitly calls the ->open method of the audio format handler at the
280 * first call.
281 *
282 * \param chunk_num The number of the chunk to get.
283 * \param afhi Describes the audio file.
284 * \param audio_format_id Determines the afh.
285 * \param map The memory mapped audio file.
286 * \param mapsize Passed to the afh's ->open() method.
287 * \param buf Result pointer.
288 * \param len The length of the chunk in bytes.
289 * \param afh_context Value/result, determines whether ->open() is called.
290 *
291 * Upon return, \a buf will point so memory inside \a map. The returned buffer
292 * must therefore not be freed by the caller.
293 *
294 * \return Standard.
295 */
296 __must_check int afh_get_chunk(long unsigned chunk_num, struct afh_info *afhi,
297 uint8_t audio_format_id, const void *map, size_t mapsize,
298 const char **buf, size_t *len, void **afh_context)
299 {
300 struct audio_format_handler *afh = afl + audio_format_id;
301
302 if (afh_supports_dynamic_chunks(audio_format_id)) {
303 int ret;
304
305 if (!*afh_context) {
306 ret = afh->open(map, mapsize, afh_context);
307 if (ret < 0)
308 return ret;
309 }
310 ret = afl[audio_format_id].get_chunk(chunk_num, *afh_context,
311 buf, len);
312 if (ret < 0) {
313 afh->close(*afh_context);
314 *afh_context = NULL;
315 }
316 return ret;
317 } else {
318 size_t pos = afhi->chunk_table[chunk_num];
319 *buf = map + pos;
320 *len = get_chunk_len(chunk_num, afhi);
321 return 0;
322 }
323 }
324
325 /**
326 * Deallocate resources allocated due to dynamic chunk handling.
327 *
328 * This function should be called if afh_get_chunk() was called at least once.
329 * It is OK to call it even for audio formats which do not support dynamic
330 * chunks, in which case the function does nothing.
331 *
332 * \param afh_context As returned from the ->open method of the afh.
333 * \param audio_format_id Determines the afh.
334 */
335 void afh_close(void *afh_context, uint8_t audio_format_id)
336 {
337 struct audio_format_handler *afh = afl + audio_format_id;
338
339 if (!afh_supports_dynamic_chunks(audio_format_id))
340 return;
341 if (!afh->close)
342 return;
343 if (!afh_context)
344 return;
345 afh->close(afh_context);
346 }
347
348 /**
349 * Find a suitable start chunk.
350 *
351 * \param approx_chunk_num Upper bound for the chunk number to return.
352 * \param afhi Needed for the chunk table.
353 * \param audio_format_id Determines the afh.
354 *
355 * \return For audio format handlers which support dynamic chunks, the function
356 * returns the given chunk number. Otherwise it returns the first non-empty
357 * chunk <= \a approx_chunk_num.
358 *
359 * \sa \ref afh_get_chunk().
360 */
361 int32_t afh_get_start_chunk(int32_t approx_chunk_num,
362 const struct afh_info *afhi, uint8_t audio_format_id)
363 {
364 int32_t k;
365
366 if (afh_supports_dynamic_chunks(audio_format_id))
367 return approx_chunk_num;
368
369 for (k = PARA_MAX(0, approx_chunk_num); k >= 0; k--)
370 if (get_chunk_len(k, afhi) > 0)
371 return k;
372 return 0;
373 }
374
375 /**
376 * Get the header of an audio file.
377 *
378 * \param afhi The audio file handler data describing the file.
379 * \param audio_format_id Determines the audio format handler.
380 * \param map The data of the audio file.
381 * \param mapsize The amount of bytes of the mmapped audio file.
382 * \param buf The length of the header is stored here.
383 * \param len Points to a buffer containing the header on return.
384 *
385 * This function sets \a buf to \p NULL and \a len to zero if \a map or \a
386 * afhi is \p NULL, or if the current audio format does not need special
387 * header treatment.
388 *
389 * Otherwise, it is checked whether the audio format handler given by
390 * \a audio_format_id defines a ->get_header() method. If it does, this
391 * method is called to obtain the header. If ->get_header() is \p NULL,
392 * a reference to the first chunk of the audio file is returned.
393 *
394 * Once the header is no longer needed, the caller must call \ref
395 * afh_free_header() to free the resources allocated by this function.
396 */
397 void afh_get_header(struct afh_info *afhi, uint8_t audio_format_id,
398 void *map, size_t mapsize, char **buf, size_t *len)
399 {
400 struct audio_format_handler *afh = afl + audio_format_id;
401
402 if (!map || !afhi || !afhi->header_len) {
403 *buf = NULL;
404 *len = 0;
405 return;
406 }
407 if (!afh->get_header) {
408 *len = afhi->header_len;
409 *buf = map;
410 return;
411 }
412 afh->get_header(map, mapsize, buf, len);
413 }
414
415 /**
416 * Deallocate any resources obtained from afh_get_header().
417 *
418 * \param header_buf Pointer obtained via afh_get_header().
419 * \param audio_format_id Determines the audio format handler.
420 */
421 void afh_free_header(char *header_buf, uint8_t audio_format_id)
422 {
423 struct audio_format_handler *afh = afl + audio_format_id;
424
425 if (afh->get_header)
426 free(header_buf);
427 }
428
429 /**
430 * Pretty-print the contents of a struct afh_info into a buffer.
431 *
432 * \param audio_format_num The audio format number.
433 * \param afhi Pointer to the structure that contains the information.
434 * \param result Pretty-printed ahfi is here after the call.
435 *
436 * The \a result buffer is dynamically allocated and should be freed by the
437 * caller.
438 *
439 * \return The number of bytes. This function never fails.
440 */
441 unsigned afh_get_afhi_txt(int audio_format_num, struct afh_info *afhi, char **result)
442 {
443 return xasprintf(result, "%s: %dkbit/s\n" /* bitrate */
444 "%s: %s\n" /* format */
445 "%s: %dHz\n" /* frequency */
446 "%s: %d\n" /* channels */
447 "%s: %" PRIu32 "\n" /* seconds total */
448 "%s: %lu: %lu\n" /* chunk time */
449 "%s: %" PRIu32 "\n" /* num chunks */
450 "%s: %" PRIu32 "\n" /* max chunk size */
451 "%s: %s\n" /* techinfo */
452 "%s: %s\n" /* artist */
453 "%s: %s\n" /* title */
454 "%s: %s\n" /* year */
455 "%s: %s\n" /* album */
456 "%s: %s\n", /* comment */
457 status_item_list[SI_BITRATE], afhi->bitrate,
458 status_item_list[SI_FORMAT], audio_format_name(audio_format_num),
459 status_item_list[SI_FREQUENCY], afhi->frequency,
460 status_item_list[SI_CHANNELS], afhi->channels,
461 status_item_list[SI_SECONDS_TOTAL], afhi->seconds_total,
462 status_item_list[SI_CHUNK_TIME], (long unsigned)afhi->chunk_tv.tv_sec,
463 (long unsigned)afhi->chunk_tv.tv_usec,
464 status_item_list[SI_NUM_CHUNKS], afhi->chunks_total,
465 status_item_list[SI_MAX_CHUNK_SIZE], afhi->max_chunk_size,
466 status_item_list[SI_TECHINFO], afhi->techinfo? afhi->techinfo : "",
467 status_item_list[SI_ARTIST], afhi->tags.artist? afhi->tags.artist : "",
468 status_item_list[SI_TITLE], afhi->tags.title? afhi->tags.title : "",
469 status_item_list[SI_YEAR], afhi->tags.year? afhi->tags.year : "",
470 status_item_list[SI_ALBUM], afhi->tags.album? afhi->tags.album : "",
471 status_item_list[SI_COMMENT], afhi->tags.comment? afhi->tags.comment : ""
472 );
473 }
474
475 /**
476 * Determine the maximal chunk size by investigating the chunk table.
477 *
478 * \param afhi Value/result.
479 *
480 * This function iterates over the chunk table and sets ->max_chunk_size
481 * accordingly. The function exists only for backward compatibility since as of
482 * version 0.6.0, para_server stores the maximal chunk size in its database.
483 * This function is only called if the database value is zero, indicating that
484 * the file was added by an older server version.
485 */
486 void set_max_chunk_size(struct afh_info *afhi)
487 {
488 uint32_t n, max = 0, old = 0;
489
490 for (n = 0; n <= afhi->chunks_total; n++) {
491 uint32_t val = afhi->chunk_table[n];
492 /*
493 * If the first chunk is the header, do not consider it for the
494 * calculation of the largest chunk size.
495 */
496 if (n == 0 || (n == 1 && afhi->header_len > 0)) {
497 old = val;
498 continue;
499 }
500 max = PARA_MAX(max, val - old);
501 old = val;
502 }
503 afhi->max_chunk_size = max;
504 }
505
506 /**
507 * Create a copy of the given file with altered meta tags.
508 *
509 * \param audio_format_id Specifies the audio format.
510 * \param map The (read-only) memory map of the input file.
511 * \param mapsize The size of the input file in bytes.
512 * \param tags The new tags.
513 * \param output_fd Altered file is created using this file descriptor.
514 * \param filename The name of the temporary output file.
515 *
516 * This calls the ->rewrite_tags method of the audio format handler associated
517 * with \a audio_format_id to create a copy of the memory-mapped file given
518 * by \a map and \a mapsize, but with altered tags according to \a tags. If
519 * the audio format handler for \a audio_format_id lacks this optional method,
520 * the function returns (the paraslash error code of) \p ENOTSUP.
521 *
522 * \return Standard.
523 */
524 int afh_rewrite_tags(int audio_format_id, void *map, size_t mapsize,
525 struct taginfo *tags, int output_fd, const char *filename)
526 {
527 struct audio_format_handler *afh = afl + audio_format_id;
528
529 if (!afh->rewrite_tags)
530 return -ERRNO_TO_PARA_ERROR(ENOTSUP);
531 return afh->rewrite_tags(map, mapsize, tags, output_fd, filename);
532 }