afh_common: Improve documentation of clear_afh().
[paraslash.git] / afh_common.c
1 /*
2 * Copyright (C) 1997-2014 Andre Noll <maan@systemlinux.org>
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 /* The mp3 audio format handler does not need any libs. */
19 void mp3_init(struct audio_format_handler *);
20
21 #ifdef HAVE_OGGVORBIS
22 void ogg_init(struct audio_format_handler *);
23 #endif
24 #ifdef HAVE_FAAD
25 void aac_afh_init(struct audio_format_handler *);
26 #endif
27 #ifdef HAVE_SPEEX
28 void spx_afh_init(struct audio_format_handler *);
29 #endif
30 #ifdef HAVE_FLAC
31 void flac_afh_init(struct audio_format_handler *);
32 #endif
33
34 #ifdef HAVE_OPUS
35 void opus_afh_init(struct audio_format_handler *);
36 #endif
37
38 void wma_afh_init(struct audio_format_handler *);
39
40 /** The list of all status items */
41 const char *status_item_list[] = {STATUS_ITEM_ARRAY};
42
43 /**
44 * The list of supported audio formats.
45 *
46 * We always define the full array of audio formats even if some audio formats
47 * were not compiled in. This is because for each audio file the number of its
48 * audio format is stored in the database. We don't want that numbers to become
49 * stale just because the user installed a new version of paraslash that
50 * supports a different set of audio formats.
51 *
52 * It can still be easily detected whether an audio format is compiled in by
53 * checking if the init function pointer is not \p NULL.
54 */
55 static struct audio_format_handler afl[] = {
56 {
57 .name = "mp3",
58 .init = mp3_init,
59 },
60 {
61 .name = "ogg",
62 #ifdef HAVE_OGGVORBIS
63 .init = ogg_init,
64 #endif
65 },
66 {
67 .name = "aac",
68 #ifdef HAVE_FAAD
69 .init = aac_afh_init,
70 #endif
71 },
72 {
73 .name = "wma",
74 .init = wma_afh_init,
75 },
76 {
77 .name = "spx",
78 #ifdef HAVE_SPEEX
79 .init = spx_afh_init,
80 #endif
81 },
82 {
83 .name = "flac",
84 #ifdef HAVE_FLAC
85 .init = flac_afh_init,
86 #endif
87 },
88 {
89 .name = "opus",
90 #ifdef HAVE_OPUS
91 .init = opus_afh_init,
92 #endif
93 },
94 {
95 .name = NULL,
96 }
97 };
98
99 static inline int next_audio_format(int format)
100 {
101 for (;;) {
102 if (!afl[format].name)
103 return format;
104 format++;
105 if (afl[format].init)
106 return format;
107 }
108
109 }
110
111 /** Iterate over each supported audio format. */
112 #define FOR_EACH_AUDIO_FORMAT(i) for (i = 0; afl[i].name; i = next_audio_format(i))
113
114 /**
115 * Call the init function of each supported audio format handler.
116 */
117 void afh_init(void)
118 {
119 int i;
120
121 PARA_INFO_LOG("supported audio formats: %s\n", AUDIO_FORMAT_HANDLERS);
122 FOR_EACH_AUDIO_FORMAT(i) {
123 PARA_NOTICE_LOG("initializing %s handler\n",
124 audio_format_name(i));
125 afl[i].init(&afl[i]);
126 }
127 }
128
129 /**
130 * Guess the audio format judging from filename.
131 *
132 * \param name The filename.
133 *
134 * \return This function returns \p -E_AUDIO_FORMAT if it has no idea what kind
135 * of audio file this might be. Otherwise the (non-negative) number of the
136 * audio format is returned.
137 */
138 int guess_audio_format(const char *name)
139 {
140 int i,j, len = strlen(name);
141
142 FOR_EACH_AUDIO_FORMAT(i) {
143 for (j = 0; afl[i].suffixes[j]; j++) {
144 const char *p = afl[i].suffixes[j];
145 int plen = strlen(p);
146 if (len < plen + 1)
147 continue;
148 if (name[len - plen - 1] != '.')
149 continue;
150 if (strcasecmp(name + len - plen, p))
151 continue;
152 // PARA_DEBUG_LOG("might be %s\n", audio_format_name(i));
153 return i;
154 }
155 }
156 return -E_AUDIO_FORMAT;
157 }
158
159 /**
160 * Call get_file_info() to obtain an afhi structure.
161 *
162 * \param path The full path of the audio file.
163 * \param data Pointer to the contents of the (mapped) file.
164 * \param size The file size in bytes.
165 * \param fd The open file descriptor.
166 * \param afhi Result pointer.
167 *
168 * \return The number of the audio format on success, \p -E_AUDIO_FORMAT if no
169 * compiled in audio format handler is able to handler the file.
170 *
171 * This function tries to find an audio format handler that can interpret the
172 * file given by \a data and \a size.
173 *
174 * It first tries to determine the audio format from the filename given by \a
175 * path. If this doesn't work, all other audio format handlers are tried until
176 * one is found that can handle the file.
177 */
178 int compute_afhi(const char *path, char *data, size_t size, int fd,
179 struct afh_info *afhi)
180 {
181 int ret, i, format;
182
183 afhi->header_len = 0;
184 afhi->techinfo = NULL;
185 afhi->tags.artist = NULL;
186 afhi->tags.title = NULL;
187 afhi->tags.year = NULL;
188 afhi->tags.album = NULL;
189 afhi->tags.comment = NULL;
190 format = guess_audio_format(path);
191
192 if (format >= 0) {
193 ret = afl[format].get_file_info(data, size, fd, afhi);
194 if (ret >= 0) {
195 ret = format;
196 goto success;
197 }
198 }
199 FOR_EACH_AUDIO_FORMAT(i) {
200 if (i == format) /* we already tried this one to no avail */
201 continue;
202 ret = afl[i].get_file_info(data, size, fd, afhi);
203 if (ret >= 0) {
204 ret = i;
205 goto success;
206 }
207 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
208 }
209 return -E_AUDIO_FORMAT;
210 success:
211 if (!afhi->techinfo)
212 afhi->techinfo = para_strdup(NULL);
213 if (!afhi->tags.artist)
214 afhi->tags.artist = para_strdup(NULL);
215 if (!afhi->tags.title)
216 afhi->tags.title = para_strdup(NULL);
217 if (!afhi->tags.year)
218 afhi->tags.year = para_strdup(NULL);
219 if (!afhi->tags.album)
220 afhi->tags.album = para_strdup(NULL);
221 if (!afhi->tags.comment)
222 afhi->tags.comment = para_strdup(NULL);
223 PARA_DEBUG_LOG("techinfo: %s\n", afhi->techinfo);
224 PARA_DEBUG_LOG("artist: %s\n", afhi->tags.artist);
225 PARA_DEBUG_LOG("title: %s\n", afhi->tags.title);
226 PARA_DEBUG_LOG("year: %s\n", afhi->tags.year);
227 PARA_DEBUG_LOG("album: %s\n", afhi->tags.album);
228 PARA_DEBUG_LOG("comment: %s\n", afhi->tags.comment);
229 return ret;
230 }
231
232 /**
233 * Deallocate the contents of an afh_info structure.
234 *
235 * \param afhi The structure to clear.
236 *
237 * This only frees the memory the various pointer fields of \a afhi point to.
238 * It does *not* free \a afhi itself.
239 */
240 void clear_afhi(struct afh_info *afhi)
241 {
242 if (!afhi)
243 return;
244 free(afhi->chunk_table);
245 free(afhi->techinfo);
246 free(afhi->tags.artist);
247 free(afhi->tags.title);
248 free(afhi->tags.year);
249 free(afhi->tags.album);
250 free(afhi->tags.comment);
251 }
252
253 /**
254 * Get the name of the given audio format.
255 *
256 * \param i The audio format number.
257 *
258 * \return This returns a pointer to statically allocated memory so it
259 * must not be freed by the caller.
260 */
261 const char *audio_format_name(int i)
262 {
263 if (i < 0 || i >= ARRAY_SIZE(afl) - 1)
264 return "???";
265 return afl[i].name;
266 }
267
268 /**
269 * Get one chunk of audio data.
270 *
271 * \param chunk_num The number of the chunk to get.
272 * \param afhi Describes the audio file.
273 * \param map The memory mapped audio file.
274 * \param buf Result pointer.
275 * \param len The length of the chunk in bytes.
276 *
277 * Upon return, \a buf will point so memory inside \a map. The returned buffer
278 * must therefore not be freed by the caller.
279 */
280 void afh_get_chunk(long unsigned chunk_num, struct afh_info *afhi,
281 void *map, const char **buf, size_t *len)
282 {
283 size_t pos = afhi->chunk_table[chunk_num];
284 *buf = map + pos;
285 *len = afhi->chunk_table[chunk_num + 1] - pos;
286 }
287
288 /**
289 * Get the header of an audio file.
290 *
291 * \param afhi The audio file handler data describing the file.
292 * \param audio_format_id Determines the audio format handler.
293 * \param map The data of the audio file.
294 * \param mapsize The amount of bytes of the mmapped audio file.
295 * \param buf The length of the header is stored here.
296 * \param len Points to a buffer containing the header on return.
297 *
298 * This function sets \a buf to \p NULL and \a len to zero if \a map or \a
299 * afhi is \p NULL, or if the current audio format does not need special
300 * header treatment.
301 *
302 * Otherwise, it is checked whether the audio format handler given by
303 * \a audio_format_id defines a ->get_header() method. If it does, this
304 * method is called to obtain the header. If ->get_header() is \p NULL,
305 * a reference to the first chunk of the audio file is returned.
306 *
307 * Once the header is no longer needed, the caller must call \ref
308 * afh_free_header() to free the resources allocated by this function.
309 */
310 void afh_get_header(struct afh_info *afhi, uint8_t audio_format_id,
311 void *map, size_t mapsize, char **buf, size_t *len)
312 {
313 struct audio_format_handler *afh = afl + audio_format_id;
314
315 if (!map || !afhi || !afhi->header_len) {
316 *buf = NULL;
317 *len = 0;
318 return;
319 }
320 if (!afh->get_header) {
321 *len = afhi->header_len;
322 *buf = map;
323 return;
324 }
325 afh->get_header(map, mapsize, buf, len);
326 }
327
328 /**
329 * Deallocate any resources obtained from afh_get_header().
330 *
331 * \param header_buf Pointer obtained via afh_get_header().
332 * \param audio_format_id Determines the audio format handler.
333 */
334 void afh_free_header(char *header_buf, uint8_t audio_format_id)
335 {
336 struct audio_format_handler *afh = afl + audio_format_id;
337
338 if (afh->get_header)
339 free(header_buf);
340 }
341
342 /**
343 * Pretty-print the contents of a struct afh_info into a buffer.
344 *
345 * \param audio_format_num The audio format number.
346 * \param afhi Pointer to the structure that contains the information.
347 * \param result Pretty-printed ahfi is here after the call.
348 *
349 * The \a result buffer is dynamically allocated and should be freed by the
350 * caller.
351 *
352 * \return The number of bytes. This function never fails.
353 */
354 unsigned afh_get_afhi_txt(int audio_format_num, struct afh_info *afhi, char **result)
355 {
356 return xasprintf(result, "%s: %dkbit/s\n" /* bitrate */
357 "%s: %s\n" /* format */
358 "%s: %dHz\n" /* frequency */
359 "%s: %d\n" /* channels */
360 "%s: %lu\n" /* seconds total */
361 "%s: %lu: %lu\n" /* chunk time */
362 "%s: %lu\n" /* num chunks */
363 "%s: %s\n" /* techinfo */
364 "%s: %s\n" /* artist */
365 "%s: %s\n" /* title */
366 "%s: %s\n" /* year */
367 "%s: %s\n" /* album */
368 "%s: %s\n", /* comment */
369 status_item_list[SI_BITRATE], afhi->bitrate,
370 status_item_list[SI_FORMAT], audio_format_name(audio_format_num),
371 status_item_list[SI_FREQUENCY], afhi->frequency,
372 status_item_list[SI_CHANNELS], afhi->channels,
373 status_item_list[SI_SECONDS_TOTAL], afhi->seconds_total,
374 status_item_list[SI_CHUNK_TIME], (long unsigned)afhi->chunk_tv.tv_sec,
375 (long unsigned)afhi->chunk_tv.tv_usec,
376 status_item_list[SI_NUM_CHUNKS], afhi->chunks_total,
377 status_item_list[SI_TECHINFO], afhi->techinfo? afhi->techinfo : "",
378 status_item_list[SI_ARTIST], afhi->tags.artist? afhi->tags.artist : "",
379 status_item_list[SI_TITLE], afhi->tags.title? afhi->tags.title : "",
380 status_item_list[SI_YEAR], afhi->tags.year? afhi->tags.year : "",
381 status_item_list[SI_ALBUM], afhi->tags.album? afhi->tags.album : "",
382 status_item_list[SI_COMMENT], afhi->tags.comment? afhi->tags.comment : ""
383 );
384 }