build: Convert alsa detection to new macros.
[paraslash.git] / mp3_afh.c
1 /*
2 * Copyright (C) 2003 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file mp3_afh.c para_server's mp3 audio format handler */
8
9 /*
10 * This file is based in part on mp3tech.c and mp3tech.h, Copyright (C)
11 * 2000-2001 Cedric Tefft <cedric@earthling.net>, which in turn is based
12 * in part on
13 *
14 * * MP3Info 0.5 by Ricardo Cerqueira <rmc@rccn.net>
15 * * MP3Stat 0.9 by Ed Sweetman <safemode@voicenet.com> and
16 * Johannes Overmann <overmann@iname.com>
17 */
18
19 #include <regex.h>
20
21 #include "para.h"
22 #include "error.h"
23 #include "afh.h"
24 #include "string.h"
25
26 /*
27 * MIN_CONSEC_GOOD_FRAMES defines how many consecutive valid MP3 frames we need
28 * to see before we decide we are looking at a real MP3 file
29 */
30 #define MIN_CONSEC_GOOD_FRAMES 4
31 #define FRAME_HEADER_SIZE 4
32 #define MIN_FRAME_SIZE 21
33
34 struct mp3header {
35 unsigned long sync;
36 unsigned int version;
37 unsigned int layer;
38 unsigned int crc;
39 unsigned int bitrate;
40 unsigned int freq;
41 unsigned int padding;
42 unsigned int mode;
43 unsigned int copyright;
44 unsigned int original;
45 unsigned int emphasis;
46 };
47
48 static const int frequencies[3][4] = {
49 {22050,24000,16000,50000}, /* MPEG 2.0 */
50 {44100,48000,32000,50000}, /* MPEG 1.0 */
51 {11025,12000,8000,50000} /* MPEG 2.5 */
52 };
53
54 static const int mp3info_bitrate[2][3][14] = {
55 { /* MPEG 2.0 */
56 {32,48,56,64,80,96,112,128,144,160,176,192,224,256}, /* layer 1 */
57 {8,16,24,32,40,48,56,64,80,96,112,128,144,160}, /* layer 2 */
58 {8,16,24,32,40,48,56,64,80,96,112,128,144,160} /* layer 3 */
59 },
60
61 { /* MPEG 1.0 */
62 {32,64,96,128,160,192,224,256,288,320,352,384,416,448}, /* layer 1 */
63 {32,48,56,64,80,96,112,128,160,192,224,256,320,384}, /* layer 2 */
64 {32,40,48,56,64,80,96,112,128,160,192,224,256,320} /* layer 3 */
65 }
66 };
67
68 static const int frame_size_index[] = {24000, 72000, 72000};
69 static const char *mode_text[] = {"stereo", "joint stereo", "dual channel", "mono", "invalid"};
70
71 #ifdef HAVE_ID3TAG
72
73 #include <id3tag.h>
74
75 static char *get_utf8(id3_ucs4_t const *string)
76 {
77 if (!string)
78 return NULL;
79 return (char *)id3_ucs4_utf8duplicate(string);
80 }
81
82 static char *get_stringlist(union id3_field *field)
83 {
84 unsigned int k, nstrings = id3_field_getnstrings(field);
85 char *result = NULL;
86
87 for (k = 0; k < nstrings; k++) {
88 char *tmp = (char *)get_utf8(id3_field_getstrings(field, k));
89 if (result) {
90 char *tmp2 = result;
91 result = make_message("%s %s", tmp2, tmp);
92 free(tmp);
93 free(tmp2);
94 } else
95 result = tmp;
96 }
97 return result;
98 }
99
100 static char *get_string(union id3_field *field)
101 {
102 id3_ucs4_t const *string = id3_field_getfullstring(field);
103
104 return get_utf8(string);
105 }
106
107 #define FOR_EACH_FIELD(f, j, fr) for (j = 0; j < (fr)->nfields && \
108 (f = id3_frame_field((fr), j)); j++)
109
110 static char *get_strings(struct id3_frame *fr)
111 {
112 int j;
113 union id3_field *field;
114
115 FOR_EACH_FIELD(field, j, fr) {
116 enum id3_field_type type = id3_field_type(field);
117
118 if (type == ID3_FIELD_TYPE_STRINGLIST)
119 return get_stringlist(field);
120 if (type == ID3_FIELD_TYPE_STRINGFULL)
121 return get_string(field);
122 }
123 return NULL;
124 }
125
126 /* this only sets values which are undefined so far */
127 static void parse_frames(struct id3_tag *id3_t, struct taginfo *tags)
128 {
129 int i;
130
131 for (i = 0; i < id3_t->nframes; i++) {
132 struct id3_frame *fr = id3_t->frames[i];
133 if (!strcmp(fr->id, ID3_FRAME_TITLE)) {
134 if (!tags->title)
135 tags->title = get_strings(fr);
136 continue;
137 }
138 if (!strcmp(fr->id, ID3_FRAME_ARTIST)) {
139 if (!tags->artist)
140 tags->artist = get_strings(fr);
141 continue;
142 }
143 if (!strcmp(fr->id, ID3_FRAME_ALBUM)) {
144 if (!tags->album)
145 tags->album = get_strings(fr);
146 continue;
147 }
148 if (!strcmp(fr->id, ID3_FRAME_YEAR)) {
149 if (!tags->year)
150 tags->year = get_strings(fr);
151 continue;
152 }
153 if (!strcmp(fr->id, ID3_FRAME_COMMENT)) {
154 if (!tags->comment)
155 tags->comment = get_strings(fr);
156 continue;
157 }
158 }
159 }
160
161 static int mp3_get_id3(unsigned char *map, size_t numbytes, __a_unused int fd,
162 struct taginfo *tags)
163 {
164 int ret = 0;
165 struct id3_tag *id3_t;
166
167 /* id3v2 tags are usually located at the beginning. */
168 id3_t = id3_tag_parse(map, numbytes);
169 if (id3_t) {
170 parse_frames(id3_t, tags);
171 ret |= 2;
172 id3_tag_delete(id3_t);
173 }
174 /* Also look for an id3v1 tag at the end of the file. */
175 if (numbytes >= 128) {
176 id3_t = id3_tag_parse(map + numbytes - 128, 128);
177 if (id3_t) {
178 parse_frames(id3_t, tags);
179 ret |= 1;
180 id3_tag_delete(id3_t);
181 }
182 }
183 return ret;
184 }
185
186 #else /* HAVE_ID3TAG */
187
188 /*
189 * Remove trailing whitespace from the end of a string
190 */
191 static char *unpad(char *string)
192 {
193 char *pos = string + strlen(string) - 1;
194 while (para_isspace(pos[0]))
195 (pos--)[0] = 0;
196 return string;
197 }
198
199 static int mp3_get_id3(unsigned char *map, size_t numbytes, __a_unused int fd,
200 struct taginfo *tags)
201 {
202 char title[31], artist[31], album[31], year[5], comment[31];
203 off_t fpos;
204
205 if (numbytes < 128 || strncmp("TAG", (char *)map + numbytes - 128, 3)) {
206 PARA_DEBUG_LOG("no id3 v1 tag\n");
207 return 0;
208 }
209 fpos = numbytes - 125;
210 memcpy(title, map + fpos, 30);
211 fpos += 30;
212 title[30] = '\0';
213 memcpy(artist, map + fpos, 30);
214 fpos += 30;
215 artist[30] = '\0';
216 memcpy(album, map + fpos, 30);
217 fpos += 30;
218 album[30] = '\0';
219 memcpy(year, map + fpos, 4);
220 fpos += 4;
221 year[4] = '\0';
222 memcpy(comment, map + fpos, 30);
223 comment[30] = '\0';
224 unpad(title);
225 unpad(artist);
226 unpad(album);
227 unpad(year);
228 unpad(comment);
229 tags->artist = para_strdup(artist);
230 tags->title = para_strdup(title);
231 tags->year = para_strdup(year);
232 tags->album = para_strdup(album);
233 tags->comment = para_strdup(comment);
234 return 1;
235 }
236 #endif /* HAVE_ID3TAG */
237
238 static int header_frequency(struct mp3header *h)
239 {
240 if (h->version > 2 || h->freq > 3)
241 return -E_HEADER_FREQ;
242 return frequencies[h->version][h->freq];
243 }
244
245 static const char *header_mode(struct mp3header *h)
246 {
247 if (h->mode > 4)
248 h->mode = 4; /* invalid */
249 return mode_text[h->mode];
250 }
251
252 static int header_channels(struct mp3header *h)
253 {
254 if (h->mode > 3)
255 return 0;
256 if (h->mode < 3)
257 return 2;
258 return 1;
259 }
260
261 static int header_bitrate(struct mp3header *h)
262 {
263 if (!h->layer || h->layer > 3 || h->bitrate > 14 || !h->bitrate)
264 return -E_HEADER_BITRATE;
265 return mp3info_bitrate[h->version & 1][3 - h->layer][h->bitrate - 1];
266 }
267
268 static int frame_length(struct mp3header *header)
269 {
270 int hb, hf = header_frequency(header);
271
272 if (hf < 0)
273 return hf;
274 hb = header_bitrate(header);
275 if (hb < 0)
276 return hb;
277 if (header->sync != 0xFFE || header->layer > 3)
278 return -E_FRAME;
279 return frame_size_index[3 - header->layer] *
280 ((header->version & 1) + 1) * hb / hf
281 + header->padding;
282 }
283
284 static int compare_headers(struct mp3header *h1,struct mp3header *h2)
285 {
286 if ((*(unsigned int*)h1) == (*(unsigned int*)h2))
287 return 1;
288 if ((h1->version == h2->version) &&
289 (h1->layer == h2->layer) &&
290 (h1->crc == h2->crc) &&
291 (h1->freq == h2->freq) &&
292 (h1->mode == h2->mode) &&
293 (h1->copyright == h2->copyright) &&
294 (h1->original == h2->original) &&
295 (h1->emphasis == h2->emphasis))
296 return 1;
297 return 0;
298 }
299
300 /*
301 * get next MP3 frame header.
302 *
303 * On success, the header frame length is returned and the given header
304 * structure that is filled in. A return value of zero means that we did not
305 * retrieve a valid frame header, and a negative return value indicates an
306 * error.
307 */
308 static int get_header(unsigned char *map, size_t numbytes, off_t *fpos,
309 struct mp3header *header)
310 {
311 int fl, ret;
312
313 if (*fpos + FRAME_HEADER_SIZE > numbytes) {
314 *fpos = numbytes - 1;
315 header->sync = 0;
316 return 0;
317 }
318 header->layer = (map[*fpos + 1] >> 1) & 3;
319 header->sync = (((int)map[*fpos]<<4) | ((int)(map[*fpos + 1]&0xE0)>>4));
320 if (map[*fpos + 1] & 0x10)
321 header->version = (map[*fpos + 1] >> 3) & 1;
322 else
323 header->version = 2;
324 if ((header->sync != 0xFFE) || (header->layer != 1)) {
325 ret = 0;
326 header->sync = 0;
327 goto out;
328 }
329 header->crc = map[*fpos + 1] & 1;
330 header->bitrate = (map[*fpos + 2] >> 4) & 0x0F;
331 header->freq = (map[*fpos + 2] >> 2) & 0x3;
332 header->padding = (map[*fpos + 2] >>1) & 0x1;
333 header->mode = (map[*fpos + 3] >> 6) & 0x3;
334 fl = frame_length(header);
335 ret = (fl >= MIN_FRAME_SIZE)? fl : -E_FRAME_LENGTH;
336 out:
337 *fpos += FRAME_HEADER_SIZE;
338 return ret;
339 }
340
341 /*
342 * find the next mp3 header
343 *
344 * Return the length of the next frame header or zero if the end of the file is
345 * reached.
346 */
347 static int mp3_seek_next_header(unsigned char *map, size_t numbytes, off_t *fpos,
348 struct mp3header *result)
349 {
350 int k, l = 0, first_len;
351 struct mp3header h, h2;
352 long valid_start = 0;
353
354 for (; *fpos < numbytes; (*fpos)++) {
355 if (map[*fpos] != 0xff)
356 continue;
357 valid_start = *fpos;
358 first_len = get_header(map, numbytes, fpos, &h);
359 if (first_len <= 0)
360 continue;
361 *fpos += first_len - FRAME_HEADER_SIZE;
362 for (k = 1; k < MIN_CONSEC_GOOD_FRAMES; k++) {
363 if ((l = get_header(map, numbytes, fpos, &h2)) <= 0)
364 break;
365 if (!compare_headers(&h, &h2))
366 break;
367 *fpos += l - FRAME_HEADER_SIZE;
368 }
369 if (k == MIN_CONSEC_GOOD_FRAMES) {
370 *fpos = valid_start;
371 *result = h2;
372 return first_len;
373 }
374 }
375 return 0;
376 }
377
378 static int find_valid_start(unsigned char *map, size_t numbytes, off_t *fpos,
379 struct mp3header *header)
380 {
381 int frame_len;
382
383 frame_len = get_header(map, numbytes, fpos, header);
384 if (frame_len < 0)
385 return frame_len;
386 if (!frame_len) {
387 frame_len = mp3_seek_next_header(map, numbytes, fpos, header);
388 if (frame_len <= 0)
389 return frame_len;
390 } else
391 *fpos -= FRAME_HEADER_SIZE;
392 if (frame_len <= 1)
393 return -E_FRAME_LENGTH;
394 return frame_len;
395 }
396
397 static int mp3_read_info(unsigned char *map, size_t numbytes, int fd,
398 struct afh_info *afhi)
399 {
400 uint64_t freq_sum = 0, br_sum = 0;
401 int fl = 0, ret, len = 0, old_br = -1, vbr = 0;
402 struct timeval total_time = {0, 0};
403 unsigned chunk_table_size = 1000; /* gets increased on demand */
404 off_t fpos = 0;
405 struct mp3header header;
406 const char *tag_versions[] = {"no", "id3v1", "id3v2", "id3v1+id3v2"};
407
408 afhi->chunks_total = 0;
409 afhi->chunk_table = para_malloc(chunk_table_size * sizeof(uint32_t));
410 while (1) {
411 int freq, br;
412 struct timeval tmp, cct; /* current chunk time */
413 fpos += len;
414 len = find_valid_start(map, numbytes, &fpos, &header);
415 if (len <= 0) {
416 size_t end;
417 ret = -E_MP3_INFO;
418 if (!afhi->chunks_total)
419 goto err_out;
420 end = afhi->chunk_table[afhi->chunks_total - 1] + fl;
421 afhi->chunk_table[afhi->chunks_total]
422 = PARA_MIN(end, numbytes);
423 break;
424 }
425 ret = header_frequency(&header);
426 if (ret < 0)
427 continue;
428 freq = ret;
429 ret = header_bitrate(&header);
430 if (ret < 0)
431 continue;
432 br = ret;
433 ret = frame_length(&header);
434 if (ret < 0)
435 continue;
436 fl = ret;
437 tmp.tv_sec = fl - header.padding;
438 tmp.tv_usec = 0;
439 tv_divide(br * 125, &tmp, &cct);
440 tv_add(&cct, &total_time, &tmp);
441 total_time = tmp;
442 if (afhi->chunks_total >= chunk_table_size) {
443 chunk_table_size *= 2;
444 afhi->chunk_table = para_realloc(afhi->chunk_table,
445 chunk_table_size * sizeof(uint32_t));
446 }
447 afhi->chunk_table[afhi->chunks_total] = fpos;
448 afhi->chunks_total++;
449 freq_sum += freq;
450 br_sum += br;
451 if (afhi->chunks_total != 1 && old_br != br)
452 vbr = 1;
453 old_br = br;
454 }
455 ret = -E_MP3_INFO;
456 if (!freq_sum || !br_sum)
457 goto err_out;
458 afhi->bitrate = br_sum / afhi->chunks_total;
459 afhi->frequency = freq_sum / afhi->chunks_total;
460 afhi->channels = header_channels(&header);
461 afhi->seconds_total = (tv2ms(&total_time) + 500) / 1000;
462 tv_divide(afhi->chunks_total, &total_time, &afhi->chunk_tv);
463 PARA_DEBUG_LOG("%lu chunks, each %lums\n", afhi->chunks_total,
464 tv2ms(&afhi->chunk_tv));
465 ret = mp3_get_id3(map, numbytes, fd, &afhi->tags);
466 afhi->techinfo = make_message("%cbr, %s, %s tags", vbr? 'v' : 'c',
467 header_mode(&header), tag_versions[ret]);
468 return 1;
469 err_out:
470 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
471 free(afhi->chunk_table);
472 return ret;
473 }
474
475 /*
476 * Read mp3 information from audio file
477 */
478 static int mp3_get_file_info(char *map, size_t numbytes, int fd,
479 struct afh_info *afhi)
480 {
481 int ret;
482
483 ret = mp3_read_info((unsigned char *)map, numbytes, fd, afhi);
484 if (ret < 0)
485 return ret;
486 if (afhi->seconds_total < 2 || !afhi->chunks_total)
487 return -E_MP3_INFO;
488 return 1;
489 }
490
491 static const char* mp3_suffixes[] = {"mp3", NULL};
492
493 /**
494 * the init function of the mp3 audio format handler
495 *
496 * \param afh pointer to the struct to initialize
497 */
498 void mp3_init(struct audio_format_handler *afh)
499 {
500 afh->get_file_info = mp3_get_file_info;
501 afh->suffixes = mp3_suffixes;
502 }