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[paraslash.git] / mp3_afh.c
1 /*
2 * Copyright (C) 2003-2010 Andre Noll <maan@systemlinux.org>
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 /** \cond some defines and structs which are only used in this file */
27
28 /*
29 * MIN_CONSEC_GOOD_FRAMES defines how many consecutive valid MP3 frames we need
30 * to see before we decide we are looking at a real MP3 file
31 */
32 #define MIN_CONSEC_GOOD_FRAMES 4
33 #define FRAME_HEADER_SIZE 4
34 #define MIN_FRAME_SIZE 21
35
36 struct mp3header {
37 unsigned long sync;
38 unsigned int version;
39 unsigned int layer;
40 unsigned int crc;
41 unsigned int bitrate;
42 unsigned int freq;
43 unsigned int padding;
44 unsigned int mode;
45 unsigned int copyright;
46 unsigned int original;
47 unsigned int emphasis;
48 };
49
50 /** \endcond */
51 static const int frequencies[3][4] = {
52 {22050,24000,16000,50000}, /* MPEG 2.0 */
53 {44100,48000,32000,50000}, /* MPEG 1.0 */
54 {11025,12000,8000,50000} /* MPEG 2.5 */
55 };
56
57 static const int mp3info_bitrate[2][3][14] = {
58 { /* MPEG 2.0 */
59 {32,48,56,64,80,96,112,128,144,160,176,192,224,256}, /* layer 1 */
60 {8,16,24,32,40,48,56,64,80,96,112,128,144,160}, /* layer 2 */
61 {8,16,24,32,40,48,56,64,80,96,112,128,144,160} /* layer 3 */
62 },
63
64 { /* MPEG 1.0 */
65 {32,64,96,128,160,192,224,256,288,320,352,384,416,448}, /* layer 1 */
66 {32,48,56,64,80,96,112,128,160,192,224,256,320,384}, /* layer 2 */
67 {32,40,48,56,64,80,96,112,128,160,192,224,256,320} /* layer 3 */
68 }
69 };
70
71 static const int frame_size_index[] = {24000, 72000, 72000};
72 static const char *mode_text[] = {"stereo", "joint stereo", "dual channel", "mono", "invalid"};
73
74 #ifdef HAVE_LIBID3TAG
75
76 #include <id3tag.h>
77
78 static char *get_latin1(id3_ucs4_t const *string)
79 {
80 if (!string)
81 return NULL;
82 return (char *)id3_ucs4_latin1duplicate(string);
83 }
84
85 static char *get_stringlist(union id3_field *field)
86 {
87 unsigned int k, nstrings = id3_field_getnstrings(field);
88 char *result = NULL;
89
90 for (k = 0; k < nstrings; k++) {
91 char *tmp = (char *)get_latin1(id3_field_getstrings(field, k));
92 if (result) {
93 char *tmp2 = result;
94 result = make_message("%s %s", tmp2, tmp);
95 free(tmp);
96 free(tmp2);
97 } else
98 result = tmp;
99 }
100 return result;
101 }
102
103 static char *get_string(union id3_field *field)
104 {
105 id3_ucs4_t const *string = id3_field_getfullstring(field);
106
107 return get_latin1(string);
108 }
109
110 #define FOR_EACH_FIELD(f, j, fr) for (j = 0; j < (fr)->nfields && \
111 (f = id3_frame_field((fr), j)); j++)
112
113 static char *get_strings(struct id3_frame *fr)
114 {
115 int j;
116 union id3_field *field;
117
118 FOR_EACH_FIELD(field, j, fr) {
119 enum id3_field_type type = id3_field_type(field);
120
121 if (type == ID3_FIELD_TYPE_STRINGLIST)
122 return get_stringlist(field);
123 if (type == ID3_FIELD_TYPE_STRINGFULL)
124 return get_string(field);
125 }
126 return NULL;
127 }
128
129 static void mp3_get_id3(__a_unused unsigned char *map,
130 __a_unused size_t numbytes, int fd, struct taginfo *tags)
131 {
132 int i;
133 struct id3_tag *id3_t;
134 struct id3_file *id3_f = id3_file_fdopen(fd, ID3_FILE_MODE_READONLY);
135
136 if (!id3_f)
137 return;
138 id3_t = id3_file_tag(id3_f);
139 if (!id3_t) {
140 id3_file_close(id3_f);
141 return;
142 }
143 for (i = 0; i < id3_t->nframes; i++) {
144 struct id3_frame *fr = id3_t->frames[i];
145 if (!strcmp(fr->id, "TIT2")) {
146 if (!tags->title)
147 tags->title = get_strings(fr);
148 continue;
149 }
150 if (!strcmp(fr->id, "TPE1")) {
151 if (!tags->artist)
152 tags->artist = get_strings(fr);
153 continue;
154 }
155 if (!strcmp(fr->id, "TALB")) {
156 if (!tags->album)
157 tags->album = get_strings(fr);
158 continue;
159 }
160 if (!strcmp(fr->id, "TDRC")) {
161 if (!tags->year)
162 tags->year = get_strings(fr);
163 continue;
164 }
165 if (!strcmp(fr->id, "COMM")) {
166 if (!tags->comment)
167 tags->comment = get_strings(fr);
168 continue;
169 }
170 }
171 id3_file_close(id3_f);
172 }
173
174 #else /* HAVE_LIBID3TAG */
175
176 /*
177 * Remove trailing whitespace from the end of a string
178 */
179 static char *unpad(char *string)
180 {
181 char *pos = string + strlen(string) - 1;
182 while (para_isspace(pos[0]))
183 (pos--)[0] = 0;
184 return string;
185 }
186
187 static void mp3_get_id3(unsigned char *map, size_t numbytes, __a_unused int fd,
188 struct taginfo *tags)
189 {
190 char title[31], artist[31], album[31], year[5], comment[31];
191 off_t fpos;
192
193 if (numbytes < 128 || strncmp("TAG", (char *)map + numbytes - 128, 3)) {
194 PARA_DEBUG_LOG("no id3 v1 tag\n");
195 return;
196 }
197 fpos = numbytes - 125;
198 memcpy(title, map + fpos, 30);
199 fpos += 30;
200 title[30] = '\0';
201 memcpy(artist, map + fpos, 30);
202 fpos += 30;
203 artist[30] = '\0';
204 memcpy(album, map + fpos, 30);
205 fpos += 30;
206 album[30] = '\0';
207 memcpy(year, map + fpos, 4);
208 fpos += 4;
209 year[4] = '\0';
210 memcpy(comment, map + fpos, 30);
211 comment[30] = '\0';
212 unpad(title);
213 unpad(artist);
214 unpad(album);
215 unpad(year);
216 unpad(comment);
217 tags->artist = para_strdup(artist);
218 tags->title = para_strdup(title);
219 tags->year = para_strdup(year);
220 tags->album = para_strdup(album);
221 tags->comment = para_strdup(comment);
222 }
223 #endif /* HAVE_LIBID3TAG */
224
225 static int header_frequency(struct mp3header *h)
226 {
227 if (h->version > 2 || h->freq > 3)
228 return -E_HEADER_FREQ;
229 return frequencies[h->version][h->freq];
230 }
231
232 static const char *header_mode(struct mp3header *h)
233 {
234 if (h->mode > 4)
235 h->mode = 4; /* invalid */
236 return mode_text[h->mode];
237 }
238
239 static int header_channels(struct mp3header *h)
240 {
241 if (h->mode > 3)
242 return 0;
243 if (h->mode < 3)
244 return 2;
245 return 1;
246 }
247
248 static int header_bitrate(struct mp3header *h)
249 {
250 if (!h->layer || h->layer > 3 || h->bitrate > 14 || !h->bitrate)
251 return -E_HEADER_BITRATE;
252 return mp3info_bitrate[h->version & 1][3 - h->layer][h->bitrate - 1];
253 }
254
255 static int frame_length(struct mp3header *header)
256 {
257 int hb, hf = header_frequency(header);
258
259 if (hf < 0)
260 return hf;
261 hb = header_bitrate(header);
262 if (hb < 0)
263 return hb;
264 if (header->sync != 0xFFE || header->layer > 3)
265 return -E_FRAME;
266 return frame_size_index[3 - header->layer] *
267 ((header->version & 1) + 1) * hb / hf
268 + header->padding;
269 }
270
271 static int compare_headers(struct mp3header *h1,struct mp3header *h2)
272 {
273 if ((*(unsigned int*)h1) == (*(unsigned int*)h2))
274 return 1;
275 if ((h1->version == h2->version) &&
276 (h1->layer == h2->layer) &&
277 (h1->crc == h2->crc) &&
278 (h1->freq == h2->freq) &&
279 (h1->mode == h2->mode) &&
280 (h1->copyright == h2->copyright) &&
281 (h1->original == h2->original) &&
282 (h1->emphasis == h2->emphasis))
283 return 1;
284 return 0;
285 }
286
287 /*
288 * get next MP3 frame header.
289 *
290 * On success, the header frame length is returned and the given header
291 * structure that is filled in. A return value of zero means that we did not
292 * retrieve a valid frame header, and a negative return value indicates an
293 * error.
294 */
295 static int get_header(unsigned char *map, size_t numbytes, off_t *fpos,
296 struct mp3header *header)
297 {
298 int fl, ret;
299
300 if (*fpos + FRAME_HEADER_SIZE > numbytes) {
301 *fpos = numbytes - 1;
302 header->sync = 0;
303 return 0;
304 }
305 header->layer = (map[*fpos + 1] >> 1) & 3;
306 header->sync = (((int)map[*fpos]<<4) | ((int)(map[*fpos + 1]&0xE0)>>4));
307 if (map[*fpos + 1] & 0x10)
308 header->version = (map[*fpos + 1] >> 3) & 1;
309 else
310 header->version = 2;
311 if ((header->sync != 0xFFE) || (header->layer != 1)) {
312 ret = 0;
313 header->sync = 0;
314 goto out;
315 }
316 header->crc = map[*fpos + 1] & 1;
317 header->bitrate = (map[*fpos + 2] >> 4) & 0x0F;
318 header->freq = (map[*fpos + 2] >> 2) & 0x3;
319 header->padding = (map[*fpos + 2] >>1) & 0x1;
320 header->mode = (map[*fpos + 3] >> 6) & 0x3;
321 fl = frame_length(header);
322 ret = (fl >= MIN_FRAME_SIZE)? fl : -E_FRAME_LENGTH;
323 out:
324 *fpos += FRAME_HEADER_SIZE;
325 return ret;
326 }
327
328 /*
329 * find the next mp3 header
330 *
331 * Return the length of the next frame header or zero if the end of the file is
332 * reached.
333 */
334 static int mp3_seek_next_header(unsigned char *map, size_t numbytes, off_t *fpos,
335 struct mp3header *result)
336 {
337 int k, l = 0, first_len;
338 struct mp3header h, h2;
339 long valid_start = 0;
340
341 for (; *fpos < numbytes; (*fpos)++) {
342 if (map[*fpos] != 0xff)
343 continue;
344 valid_start = *fpos;
345 first_len = get_header(map, numbytes, fpos, &h);
346 if (first_len <= 0)
347 continue;
348 *fpos += first_len - FRAME_HEADER_SIZE;
349 for (k = 1; k < MIN_CONSEC_GOOD_FRAMES; k++) {
350 if ((l = get_header(map, numbytes, fpos, &h2)) <= 0)
351 break;
352 if (!compare_headers(&h, &h2))
353 break;
354 *fpos += l - FRAME_HEADER_SIZE;
355 }
356 if (k == MIN_CONSEC_GOOD_FRAMES) {
357 *fpos = valid_start;
358 *result = h2;
359 return first_len;
360 }
361 }
362 return 0;
363 }
364
365 static int find_valid_start(unsigned char *map, size_t numbytes, off_t *fpos,
366 struct mp3header *header)
367 {
368 int frame_len;
369
370 frame_len = get_header(map, numbytes, fpos, header);
371 if (frame_len < 0)
372 return frame_len;
373 if (!frame_len) {
374 frame_len = mp3_seek_next_header(map, numbytes, fpos, header);
375 if (frame_len <= 0)
376 return frame_len;
377 } else
378 *fpos -= FRAME_HEADER_SIZE;
379 if (frame_len <= 1)
380 return -E_FRAME_LENGTH;
381 return frame_len;
382 }
383
384 static int mp3_read_info(unsigned char *map, size_t numbytes, int fd,
385 struct afh_info *afhi)
386 {
387 uint64_t freq_sum = 0, br_sum = 0;
388 int fl = 0, ret, len = 0, old_br = -1, vbr = 0;
389 struct timeval total_time = {0, 0};
390 unsigned chunk_table_size = 1000; /* gets increased on demand */
391 off_t fpos = 0;
392 struct mp3header header;
393
394 afhi->chunks_total = 0;
395 afhi->chunk_table = para_malloc(chunk_table_size * sizeof(uint32_t));
396 while (1) {
397 int freq, br;
398 struct timeval tmp, cct; /* current chunk time */
399 fpos += len;
400 len = find_valid_start(map, numbytes, &fpos, &header);
401 if (len <= 0) {
402 size_t end;
403 ret = -E_MP3_INFO;
404 if (!afhi->chunks_total)
405 goto err_out;
406 end = afhi->chunk_table[afhi->chunks_total - 1] + fl;
407 afhi->chunk_table[afhi->chunks_total]
408 = PARA_MIN(end, numbytes);
409 break;
410 }
411 ret = header_frequency(&header);
412 if (ret < 0)
413 continue;
414 freq = ret;
415 ret = header_bitrate(&header);
416 if (ret < 0)
417 continue;
418 br = ret;
419 ret = frame_length(&header);
420 if (ret < 0)
421 continue;
422 fl = ret;
423 tmp.tv_sec = fl;
424 tmp.tv_usec = 0;
425 tv_divide(br * 125, &tmp, &cct);
426 tv_add(&cct, &total_time, &tmp);
427 total_time = tmp;
428 if (afhi->chunks_total >= chunk_table_size) {
429 chunk_table_size *= 2;
430 afhi->chunk_table = para_realloc(afhi->chunk_table,
431 chunk_table_size * sizeof(uint32_t));
432 }
433 afhi->chunk_table[afhi->chunks_total] = fpos;
434 afhi->chunks_total++;
435 freq_sum += freq;
436 br_sum += br;
437 if (afhi->chunks_total != 1 && old_br != br)
438 vbr = 1;
439 old_br = br;
440 }
441 ret = -E_MP3_INFO;
442 if (!freq_sum || !br_sum)
443 goto err_out;
444 afhi->bitrate = br_sum / afhi->chunks_total;
445 afhi->frequency = freq_sum / afhi->chunks_total;
446 afhi->channels = header_channels(&header);
447 afhi->seconds_total = (tv2ms(&total_time) + 500) / 1000;
448 tv_divide(afhi->chunks_total, &total_time, &afhi->chunk_tv);
449 PARA_DEBUG_LOG("%lu chunks, each %lums\n", afhi->chunks_total,
450 tv2ms(&afhi->chunk_tv));
451 afhi->techinfo = make_message("%cbr, %s", vbr? 'v' : 'c',
452 header_mode(&header));
453 mp3_get_id3(map, numbytes, fd, &afhi->tags);
454 return 1;
455 err_out:
456 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
457 free(afhi->chunk_table);
458 return ret;
459 }
460
461 /*
462 * Read mp3 information from audio file
463 */
464 static int mp3_get_file_info(char *map, size_t numbytes, int fd,
465 struct afh_info *afhi)
466 {
467 int ret;
468
469 ret = mp3_read_info((unsigned char *)map, numbytes, fd, afhi);
470 if (ret < 0)
471 return ret;
472 if (afhi->seconds_total < 2 || !afhi->chunks_total)
473 return -E_MP3_INFO;
474 return 1;
475 }
476
477 static const char* mp3_suffixes[] = {"mp3", NULL};
478
479 /**
480 * the init function of the mp3 audio format handler
481 *
482 * \param afh pointer to the struct to initialize
483 */
484 void mp3_init(struct audio_format_handler *afh)
485 {
486 afh->get_file_info = mp3_get_file_info;
487 afh->suffixes = mp3_suffixes;
488 }