ff133ca563441ceb6daa02979c7a223b1c74e323
[paraslash.git] / mp3_afh.c
1 /*
2 * Copyright (C) 2003-2009 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 <osl.h>
20 #include "para.h"
21 #include "error.h"
22 #include "afh.h"
23 #include "string.h"
24
25 /** \cond some defines and structs which are only used in this file */
26
27 /*
28 * MIN_CONSEC_GOOD_FRAMES defines how many consecutive valid MP3 frames we need
29 * to see before we decide we are looking at a real MP3 file
30 */
31 #define MIN_CONSEC_GOOD_FRAMES 4
32 #define FRAME_HEADER_SIZE 4
33 #define MIN_FRAME_SIZE 21
34
35 struct mp3header {
36 unsigned long sync;
37 unsigned int version;
38 unsigned int layer;
39 unsigned int crc;
40 unsigned int bitrate;
41 unsigned int freq;
42 unsigned int padding;
43 unsigned int mode;
44 unsigned int copyright;
45 unsigned int original;
46 unsigned int emphasis;
47 };
48
49 /** \endcond */
50 static const int frequencies[3][4] = {
51 {22050,24000,16000,50000}, /* MPEG 2.0 */
52 {44100,48000,32000,50000}, /* MPEG 1.0 */
53 {11025,12000,8000,50000} /* MPEG 2.5 */
54 };
55
56 static const int mp3info_bitrate[2][3][14] = {
57 { /* MPEG 2.0 */
58 {32,48,56,64,80,96,112,128,144,160,176,192,224,256}, /* layer 1 */
59 {8,16,24,32,40,48,56,64,80,96,112,128,144,160}, /* layer 2 */
60 {8,16,24,32,40,48,56,64,80,96,112,128,144,160} /* layer 3 */
61 },
62
63 { /* MPEG 1.0 */
64 {32,64,96,128,160,192,224,256,288,320,352,384,416,448}, /* layer 1 */
65 {32,48,56,64,80,96,112,128,160,192,224,256,320,384}, /* layer 2 */
66 {32,40,48,56,64,80,96,112,128,160,192,224,256,320} /* layer 3 */
67 }
68 };
69
70 static const int frame_size_index[] = {24000, 72000, 72000};
71 static const char *mode_text[] = {"stereo", "joint stereo", "dual channel", "mono", "invalid"};
72
73 #ifdef HAVE_LIBID3TAG
74
75 #include <id3tag.h>
76
77 static char *get_latin1(id3_ucs4_t const *string)
78 {
79 if (!string)
80 return NULL;
81 return (char *)id3_ucs4_latin1duplicate(string);
82 }
83
84 static char *get_stringlist(union id3_field *field)
85 {
86 unsigned int k, nstrings = id3_field_getnstrings(field);
87 char *result = NULL;
88
89 for (k = 0; k < nstrings; k++) {
90 char *tmp = (char *)get_latin1(id3_field_getstrings(field, k));
91 if (result) {
92 char *tmp2 = result;
93 result = make_message("%s %s", tmp2, tmp);
94 free(tmp);
95 free(tmp2);
96 } else
97 result = tmp;
98 }
99 return result;
100 }
101
102 static char *get_string(union id3_field *field)
103 {
104 id3_ucs4_t const *string = id3_field_getfullstring(field);
105
106 return get_latin1(string);
107 }
108
109 #define FOR_EACH_FIELD(f, j, fr) for (j = 0; j < (fr)->nfields && \
110 (f = id3_frame_field((fr), j)); j++)
111
112 static char *get_strings(struct id3_frame *fr)
113 {
114 int j;
115 union id3_field *field;
116
117 FOR_EACH_FIELD(field, j, fr) {
118 enum id3_field_type type = id3_field_type(field);
119
120 if (type == ID3_FIELD_TYPE_STRINGLIST)
121 return get_stringlist(field);
122 if (type == ID3_FIELD_TYPE_STRINGFULL)
123 return get_string(field);
124 }
125 return NULL;
126 }
127
128 static void mp3_get_id3(__a_unused unsigned char *map,
129 __a_unused size_t numbytes, int fd, struct taginfo *tags)
130 {
131 int i;
132 struct id3_tag *id3_t;
133 struct id3_file *id3_f = id3_file_fdopen(fd, ID3_FILE_MODE_READONLY);
134
135 if (!id3_f)
136 return;
137 id3_t = id3_file_tag(id3_f);
138 if (!id3_t) {
139 id3_file_close(id3_f);
140 return;
141 }
142 for (i = 0; i < id3_t->nframes; i++) {
143 struct id3_frame *fr = id3_t->frames[i];
144 if (!strcmp(fr->id, "TIT2")) {
145 if (!tags->title)
146 tags->title = get_strings(fr);
147 continue;
148 }
149 if (!strcmp(fr->id, "TPE1")) {
150 if (!tags->artist)
151 tags->artist = get_strings(fr);
152 continue;
153 }
154 if (!strcmp(fr->id, "TALB")) {
155 if (!tags->album)
156 tags->album = get_strings(fr);
157 continue;
158 }
159 if (!strcmp(fr->id, "TDRC")) {
160 if (!tags->year)
161 tags->year = get_strings(fr);
162 continue;
163 }
164 if (!strcmp(fr->id, "COMM")) {
165 if (!tags->comment)
166 tags->comment = get_strings(fr);
167 continue;
168 }
169 }
170 id3_file_close(id3_f);
171 }
172
173 #else /* HAVE_LIBID3TAG */
174
175 /*
176 * Remove trailing whitespace from the end of a string
177 */
178 static char *unpad(char *string)
179 {
180 char *pos = string + strlen(string) - 1;
181 while (para_isspace(pos[0]))
182 (pos--)[0] = 0;
183 return string;
184 }
185
186 static void mp3_get_id3(unsigned char *map, size_t numbytes, __a_unused int fd,
187 struct taginfo *tags)
188 {
189 char title[31], artist[31], album[31], year[5], comment[31];
190 off_t fpos;
191
192 if (numbytes < 128 || strncmp("TAG", (char *)map + numbytes - 128, 3)) {
193 PARA_DEBUG_LOG("no id3 v1 tag\n");
194 return;
195 }
196 fpos = numbytes - 125;
197 memcpy(title, map + fpos, 30);
198 fpos += 30;
199 title[30] = '\0';
200 memcpy(artist, map + fpos, 30);
201 fpos += 30;
202 artist[30] = '\0';
203 memcpy(album, map + fpos, 30);
204 fpos += 30;
205 album[30] = '\0';
206 memcpy(year, map + fpos, 4);
207 fpos += 4;
208 year[4] = '\0';
209 memcpy(comment, map + fpos, 30);
210 comment[30] = '\0';
211 unpad(title);
212 unpad(artist);
213 unpad(album);
214 unpad(year);
215 unpad(comment);
216 tags->artist = para_strdup(artist);
217 tags->title = para_strdup(title);
218 tags->year = para_strdup(year);
219 tags->album = para_strdup(album);
220 tags->comment = para_strdup(comment);
221 }
222 #endif /* HAVE_LIBID3TAG */
223
224 static int header_frequency(struct mp3header *h)
225 {
226 if (h->version > 2 || h->freq > 3)
227 return -E_HEADER_FREQ;
228 return frequencies[h->version][h->freq];
229 }
230
231 static const char *header_mode(struct mp3header *h)
232 {
233 if (h->mode > 4)
234 h->mode = 4; /* invalid */
235 return mode_text[h->mode];
236 }
237
238 static int header_channels(struct mp3header *h)
239 {
240 if (h->mode > 3)
241 return 0;
242 if (h->mode < 3)
243 return 2;
244 return 1;
245 }
246
247 static int header_bitrate(struct mp3header *h)
248 {
249 if (!h->layer || h->layer > 3 || h->bitrate > 14 || !h->bitrate)
250 return -E_HEADER_BITRATE;
251 return mp3info_bitrate[h->version & 1][3 - h->layer][h->bitrate - 1];
252 }
253
254 static int frame_length(struct mp3header *header)
255 {
256 int hb, hf = header_frequency(header);
257
258 if (hf < 0)
259 return hf;
260 hb = header_bitrate(header);
261 if (hb < 0)
262 return hb;
263 if (header->sync != 0xFFE || header->layer > 3)
264 return -E_FRAME;
265 return frame_size_index[3 - header->layer] *
266 ((header->version & 1) + 1) * hb / hf
267 + header->padding;
268 }
269
270 static int compare_headers(struct mp3header *h1,struct mp3header *h2)
271 {
272 if ((*(unsigned int*)h1) == (*(unsigned int*)h2))
273 return 1;
274 if ((h1->version == h2->version) &&
275 (h1->layer == h2->layer) &&
276 (h1->crc == h2->crc) &&
277 (h1->freq == h2->freq) &&
278 (h1->mode == h2->mode) &&
279 (h1->copyright == h2->copyright) &&
280 (h1->original == h2->original) &&
281 (h1->emphasis == h2->emphasis))
282 return 1;
283 return 0;
284 }
285
286 /*
287 * get next MP3 frame header.
288 *
289 * On success, the header frame length is returned and the given header
290 * structure that is filled in. A return value of zero means that we did not
291 * retrieve a valid frame header, and a negative return value indicates an
292 * error.
293 */
294 static int get_header(unsigned char *map, size_t numbytes, off_t *fpos,
295 struct mp3header *header)
296 {
297 int fl, ret;
298
299 if (*fpos + FRAME_HEADER_SIZE > numbytes) {
300 *fpos = numbytes - 1;
301 header->sync = 0;
302 return 0;
303 }
304 header->layer = (map[*fpos + 1] >> 1) & 3;
305 header->sync = (((int)map[*fpos]<<4) | ((int)(map[*fpos + 1]&0xE0)>>4));
306 if (map[*fpos + 1] & 0x10)
307 header->version = (map[*fpos + 1] >> 3) & 1;
308 else
309 header->version = 2;
310 if ((header->sync != 0xFFE) || (header->layer != 1)) {
311 ret = 0;
312 header->sync = 0;
313 goto out;
314 }
315 header->crc = map[*fpos + 1] & 1;
316 header->bitrate = (map[*fpos + 2] >> 4) & 0x0F;
317 header->freq = (map[*fpos + 2] >> 2) & 0x3;
318 header->padding = (map[*fpos + 2] >>1) & 0x1;
319 header->mode = (map[*fpos + 3] >> 6) & 0x3;
320 fl = frame_length(header);
321 ret = (fl >= MIN_FRAME_SIZE)? fl : -E_FRAME_LENGTH;
322 out:
323 *fpos += FRAME_HEADER_SIZE;
324 return ret;
325 }
326
327 /*
328 * find the next mp3 header
329 *
330 * Return the length of the next frame header or zero if the end of the file is
331 * reached.
332 */
333 static int mp3_seek_next_header(unsigned char *map, size_t numbytes, off_t *fpos,
334 struct mp3header *result)
335 {
336 int k, l = 0, first_len;
337 struct mp3header h, h2;
338 long valid_start = 0;
339
340 for (; *fpos < numbytes; (*fpos)++) {
341 if (map[*fpos] != 0xff)
342 continue;
343 valid_start = *fpos;
344 first_len = get_header(map, numbytes, fpos, &h);
345 if (first_len <= 0)
346 continue;
347 *fpos += first_len - FRAME_HEADER_SIZE;
348 for (k = 1; k < MIN_CONSEC_GOOD_FRAMES; k++) {
349 if ((l = get_header(map, numbytes, fpos, &h2)) <= 0)
350 break;
351 if (!compare_headers(&h, &h2))
352 break;
353 *fpos += l - FRAME_HEADER_SIZE;
354 }
355 if (k == MIN_CONSEC_GOOD_FRAMES) {
356 *fpos = valid_start;
357 *result = h2;
358 return first_len;
359 }
360 }
361 return 0;
362 }
363
364 static int find_valid_start(unsigned char *map, size_t numbytes, off_t *fpos,
365 struct mp3header *header)
366 {
367 int frame_len;
368
369 frame_len = get_header(map, numbytes, fpos, header);
370 if (frame_len < 0)
371 return frame_len;
372 if (!frame_len) {
373 frame_len = mp3_seek_next_header(map, numbytes, fpos, header);
374 if (frame_len <= 0)
375 return frame_len;
376 } else
377 *fpos -= FRAME_HEADER_SIZE;
378 if (frame_len <= 1)
379 return -E_FRAME_LENGTH;
380 return frame_len;
381 }
382
383 static int mp3_read_info(unsigned char *map, size_t numbytes, int fd,
384 struct afh_info *afhi)
385 {
386 uint64_t freq_sum = 0, br_sum = 0;
387 int fl = 0, ret, len = 0, old_br = -1, vbr = 0;
388 struct timeval total_time = {0, 0};
389 unsigned chunk_table_size = 1000; /* gets increased on demand */
390 off_t fpos = 0;
391 struct mp3header header;
392
393 afhi->chunks_total = 0;
394 afhi->chunk_table = para_malloc(chunk_table_size * sizeof(uint32_t));
395 while (1) {
396 int freq, br;
397 struct timeval tmp, cct; /* current chunk time */
398 fpos += len;
399 len = find_valid_start(map, numbytes, &fpos, &header);
400 if (len <= 0) {
401 size_t end;
402 ret = -E_MP3_INFO;
403 if (!afhi->chunks_total)
404 goto err_out;
405 end = afhi->chunk_table[afhi->chunks_total - 1] + fl;
406 afhi->chunk_table[afhi->chunks_total]
407 = PARA_MIN(end, numbytes);
408 break;
409 }
410 ret = header_frequency(&header);
411 if (ret < 0)
412 continue;
413 freq = ret;
414 ret = header_bitrate(&header);
415 if (ret < 0)
416 continue;
417 br = ret;
418 ret = frame_length(&header);
419 if (ret < 0)
420 continue;
421 fl = ret;
422 tmp.tv_sec = fl;
423 tmp.tv_usec = 0;
424 tv_divide(br * 125, &tmp, &cct);
425 tv_add(&cct, &total_time, &tmp);
426 total_time = tmp;
427 if (afhi->chunks_total >= chunk_table_size) {
428 chunk_table_size *= 2;
429 afhi->chunk_table = para_realloc(afhi->chunk_table,
430 chunk_table_size * sizeof(uint32_t));
431 }
432 afhi->chunk_table[afhi->chunks_total] = fpos;
433 afhi->chunks_total++;
434 freq_sum += freq;
435 br_sum += br;
436 if (afhi->chunks_total != 1 && old_br != br)
437 vbr = 1;
438 old_br = br;
439 }
440 ret = -E_MP3_INFO;
441 if (!freq_sum || !br_sum)
442 goto err_out;
443 afhi->bitrate = br_sum / afhi->chunks_total;
444 afhi->frequency = freq_sum / afhi->chunks_total;
445 afhi->channels = header_channels(&header);
446 afhi->seconds_total = (tv2ms(&total_time) + 500) / 1000;
447 tv_divide(afhi->chunks_total, &total_time, &afhi->chunk_tv);
448 PARA_DEBUG_LOG("%lu chunks, each %lums\n", afhi->chunks_total,
449 tv2ms(&afhi->chunk_tv));
450 afhi->techinfo = make_message("%cbr, %s", vbr? 'v' : 'c',
451 header_mode(&header));
452 mp3_get_id3(map, numbytes, fd, &afhi->tags);
453 return 1;
454 err_out:
455 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
456 free(afhi->chunk_table);
457 return ret;
458 }
459
460 /*
461 * Read mp3 information from audio file
462 */
463 static int mp3_get_file_info(char *map, size_t numbytes, int fd,
464 struct afh_info *afhi)
465 {
466 int ret;
467
468 ret = mp3_read_info((unsigned char *)map, numbytes, fd, afhi);
469 if (ret < 0)
470 return ret;
471 if (afhi->seconds_total < 2 || !afhi->chunks_total)
472 return -E_MP3_INFO;
473 return 1;
474 }
475
476 static const char* mp3_suffixes[] = {"mp3", NULL};
477
478 /**
479 * the init function of the mp3 audio format handler
480 *
481 * \param afh pointer to the struct to initialize
482 */
483 void mp3_init(struct audio_format_handler *afh)
484 {
485 afh->get_file_info = mp3_get_file_info;
486 afh->suffixes = mp3_suffixes;
487 }