Merge branch 'refs/heads/t/server_cmds'
[paraslash.git] / mp3_afh.c
1 /*
2 * Copyright (C) 2003-2014 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_LIBID3TAG
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 static void mp3_get_id3(__a_unused unsigned char *map,
127 __a_unused size_t numbytes, int fd, struct taginfo *tags)
128 {
129 int i;
130 struct id3_tag *id3_t;
131 struct id3_file *id3_f = id3_file_fdopen(fd, ID3_FILE_MODE_READONLY);
132
133 if (!id3_f)
134 return;
135 id3_t = id3_file_tag(id3_f);
136 if (!id3_t) {
137 id3_file_close(id3_f);
138 return;
139 }
140 for (i = 0; i < id3_t->nframes; i++) {
141 struct id3_frame *fr = id3_t->frames[i];
142 if (!strcmp(fr->id, ID3_FRAME_TITLE)) {
143 if (!tags->title)
144 tags->title = get_strings(fr);
145 continue;
146 }
147 if (!strcmp(fr->id, ID3_FRAME_ARTIST)) {
148 if (!tags->artist)
149 tags->artist = get_strings(fr);
150 continue;
151 }
152 if (!strcmp(fr->id, ID3_FRAME_ALBUM)) {
153 if (!tags->album)
154 tags->album = get_strings(fr);
155 continue;
156 }
157 if (!strcmp(fr->id, ID3_FRAME_YEAR)) {
158 if (!tags->year)
159 tags->year = get_strings(fr);
160 continue;
161 }
162 if (!strcmp(fr->id, ID3_FRAME_COMMENT)) {
163 if (!tags->comment)
164 tags->comment = get_strings(fr);
165 continue;
166 }
167 }
168 id3_file_close(id3_f);
169 }
170
171 #else /* HAVE_LIBID3TAG */
172
173 /*
174 * Remove trailing whitespace from the end of a string
175 */
176 static char *unpad(char *string)
177 {
178 char *pos = string + strlen(string) - 1;
179 while (para_isspace(pos[0]))
180 (pos--)[0] = 0;
181 return string;
182 }
183
184 static void mp3_get_id3(unsigned char *map, size_t numbytes, __a_unused int fd,
185 struct taginfo *tags)
186 {
187 char title[31], artist[31], album[31], year[5], comment[31];
188 off_t fpos;
189
190 if (numbytes < 128 || strncmp("TAG", (char *)map + numbytes - 128, 3)) {
191 PARA_DEBUG_LOG("no id3 v1 tag\n");
192 return;
193 }
194 fpos = numbytes - 125;
195 memcpy(title, map + fpos, 30);
196 fpos += 30;
197 title[30] = '\0';
198 memcpy(artist, map + fpos, 30);
199 fpos += 30;
200 artist[30] = '\0';
201 memcpy(album, map + fpos, 30);
202 fpos += 30;
203 album[30] = '\0';
204 memcpy(year, map + fpos, 4);
205 fpos += 4;
206 year[4] = '\0';
207 memcpy(comment, map + fpos, 30);
208 comment[30] = '\0';
209 unpad(title);
210 unpad(artist);
211 unpad(album);
212 unpad(year);
213 unpad(comment);
214 tags->artist = para_strdup(artist);
215 tags->title = para_strdup(title);
216 tags->year = para_strdup(year);
217 tags->album = para_strdup(album);
218 tags->comment = para_strdup(comment);
219 }
220 #endif /* HAVE_LIBID3TAG */
221
222 static int header_frequency(struct mp3header *h)
223 {
224 if (h->version > 2 || h->freq > 3)
225 return -E_HEADER_FREQ;
226 return frequencies[h->version][h->freq];
227 }
228
229 static const char *header_mode(struct mp3header *h)
230 {
231 if (h->mode > 4)
232 h->mode = 4; /* invalid */
233 return mode_text[h->mode];
234 }
235
236 static int header_channels(struct mp3header *h)
237 {
238 if (h->mode > 3)
239 return 0;
240 if (h->mode < 3)
241 return 2;
242 return 1;
243 }
244
245 static int header_bitrate(struct mp3header *h)
246 {
247 if (!h->layer || h->layer > 3 || h->bitrate > 14 || !h->bitrate)
248 return -E_HEADER_BITRATE;
249 return mp3info_bitrate[h->version & 1][3 - h->layer][h->bitrate - 1];
250 }
251
252 static int frame_length(struct mp3header *header)
253 {
254 int hb, hf = header_frequency(header);
255
256 if (hf < 0)
257 return hf;
258 hb = header_bitrate(header);
259 if (hb < 0)
260 return hb;
261 if (header->sync != 0xFFE || header->layer > 3)
262 return -E_FRAME;
263 return frame_size_index[3 - header->layer] *
264 ((header->version & 1) + 1) * hb / hf
265 + header->padding;
266 }
267
268 static int compare_headers(struct mp3header *h1,struct mp3header *h2)
269 {
270 if ((*(unsigned int*)h1) == (*(unsigned int*)h2))
271 return 1;
272 if ((h1->version == h2->version) &&
273 (h1->layer == h2->layer) &&
274 (h1->crc == h2->crc) &&
275 (h1->freq == h2->freq) &&
276 (h1->mode == h2->mode) &&
277 (h1->copyright == h2->copyright) &&
278 (h1->original == h2->original) &&
279 (h1->emphasis == h2->emphasis))
280 return 1;
281 return 0;
282 }
283
284 /*
285 * get next MP3 frame header.
286 *
287 * On success, the header frame length is returned and the given header
288 * structure that is filled in. A return value of zero means that we did not
289 * retrieve a valid frame header, and a negative return value indicates an
290 * error.
291 */
292 static int get_header(unsigned char *map, size_t numbytes, off_t *fpos,
293 struct mp3header *header)
294 {
295 int fl, ret;
296
297 if (*fpos + FRAME_HEADER_SIZE > numbytes) {
298 *fpos = numbytes - 1;
299 header->sync = 0;
300 return 0;
301 }
302 header->layer = (map[*fpos + 1] >> 1) & 3;
303 header->sync = (((int)map[*fpos]<<4) | ((int)(map[*fpos + 1]&0xE0)>>4));
304 if (map[*fpos + 1] & 0x10)
305 header->version = (map[*fpos + 1] >> 3) & 1;
306 else
307 header->version = 2;
308 if ((header->sync != 0xFFE) || (header->layer != 1)) {
309 ret = 0;
310 header->sync = 0;
311 goto out;
312 }
313 header->crc = map[*fpos + 1] & 1;
314 header->bitrate = (map[*fpos + 2] >> 4) & 0x0F;
315 header->freq = (map[*fpos + 2] >> 2) & 0x3;
316 header->padding = (map[*fpos + 2] >>1) & 0x1;
317 header->mode = (map[*fpos + 3] >> 6) & 0x3;
318 fl = frame_length(header);
319 ret = (fl >= MIN_FRAME_SIZE)? fl : -E_FRAME_LENGTH;
320 out:
321 *fpos += FRAME_HEADER_SIZE;
322 return ret;
323 }
324
325 /*
326 * find the next mp3 header
327 *
328 * Return the length of the next frame header or zero if the end of the file is
329 * reached.
330 */
331 static int mp3_seek_next_header(unsigned char *map, size_t numbytes, off_t *fpos,
332 struct mp3header *result)
333 {
334 int k, l = 0, first_len;
335 struct mp3header h, h2;
336 long valid_start = 0;
337
338 for (; *fpos < numbytes; (*fpos)++) {
339 if (map[*fpos] != 0xff)
340 continue;
341 valid_start = *fpos;
342 first_len = get_header(map, numbytes, fpos, &h);
343 if (first_len <= 0)
344 continue;
345 *fpos += first_len - FRAME_HEADER_SIZE;
346 for (k = 1; k < MIN_CONSEC_GOOD_FRAMES; k++) {
347 if ((l = get_header(map, numbytes, fpos, &h2)) <= 0)
348 break;
349 if (!compare_headers(&h, &h2))
350 break;
351 *fpos += l - FRAME_HEADER_SIZE;
352 }
353 if (k == MIN_CONSEC_GOOD_FRAMES) {
354 *fpos = valid_start;
355 *result = h2;
356 return first_len;
357 }
358 }
359 return 0;
360 }
361
362 static int find_valid_start(unsigned char *map, size_t numbytes, off_t *fpos,
363 struct mp3header *header)
364 {
365 int frame_len;
366
367 frame_len = get_header(map, numbytes, fpos, header);
368 if (frame_len < 0)
369 return frame_len;
370 if (!frame_len) {
371 frame_len = mp3_seek_next_header(map, numbytes, fpos, header);
372 if (frame_len <= 0)
373 return frame_len;
374 } else
375 *fpos -= FRAME_HEADER_SIZE;
376 if (frame_len <= 1)
377 return -E_FRAME_LENGTH;
378 return frame_len;
379 }
380
381 static int mp3_read_info(unsigned char *map, size_t numbytes, int fd,
382 struct afh_info *afhi)
383 {
384 uint64_t freq_sum = 0, br_sum = 0;
385 int fl = 0, ret, len = 0, old_br = -1, vbr = 0;
386 struct timeval total_time = {0, 0};
387 unsigned chunk_table_size = 1000; /* gets increased on demand */
388 off_t fpos = 0;
389 struct mp3header header;
390
391 afhi->chunks_total = 0;
392 afhi->chunk_table = para_malloc(chunk_table_size * sizeof(uint32_t));
393 while (1) {
394 int freq, br;
395 struct timeval tmp, cct; /* current chunk time */
396 fpos += len;
397 len = find_valid_start(map, numbytes, &fpos, &header);
398 if (len <= 0) {
399 size_t end;
400 ret = -E_MP3_INFO;
401 if (!afhi->chunks_total)
402 goto err_out;
403 end = afhi->chunk_table[afhi->chunks_total - 1] + fl;
404 afhi->chunk_table[afhi->chunks_total]
405 = PARA_MIN(end, numbytes);
406 break;
407 }
408 ret = header_frequency(&header);
409 if (ret < 0)
410 continue;
411 freq = ret;
412 ret = header_bitrate(&header);
413 if (ret < 0)
414 continue;
415 br = ret;
416 ret = frame_length(&header);
417 if (ret < 0)
418 continue;
419 fl = ret;
420 tmp.tv_sec = fl - header.padding;
421 tmp.tv_usec = 0;
422 tv_divide(br * 125, &tmp, &cct);
423 tv_add(&cct, &total_time, &tmp);
424 total_time = tmp;
425 if (afhi->chunks_total >= chunk_table_size) {
426 chunk_table_size *= 2;
427 afhi->chunk_table = para_realloc(afhi->chunk_table,
428 chunk_table_size * sizeof(uint32_t));
429 }
430 afhi->chunk_table[afhi->chunks_total] = fpos;
431 afhi->chunks_total++;
432 freq_sum += freq;
433 br_sum += br;
434 if (afhi->chunks_total != 1 && old_br != br)
435 vbr = 1;
436 old_br = br;
437 }
438 ret = -E_MP3_INFO;
439 if (!freq_sum || !br_sum)
440 goto err_out;
441 afhi->bitrate = br_sum / afhi->chunks_total;
442 afhi->frequency = freq_sum / afhi->chunks_total;
443 afhi->channels = header_channels(&header);
444 afhi->seconds_total = (tv2ms(&total_time) + 500) / 1000;
445 tv_divide(afhi->chunks_total, &total_time, &afhi->chunk_tv);
446 PARA_DEBUG_LOG("%lu chunks, each %lums\n", afhi->chunks_total,
447 tv2ms(&afhi->chunk_tv));
448 afhi->techinfo = make_message("%cbr, %s", vbr? 'v' : 'c',
449 header_mode(&header));
450 mp3_get_id3(map, numbytes, fd, &afhi->tags);
451 return 1;
452 err_out:
453 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
454 free(afhi->chunk_table);
455 return ret;
456 }
457
458 /*
459 * Read mp3 information from audio file
460 */
461 static int mp3_get_file_info(char *map, size_t numbytes, int fd,
462 struct afh_info *afhi)
463 {
464 int ret;
465
466 ret = mp3_read_info((unsigned char *)map, numbytes, fd, afhi);
467 if (ret < 0)
468 return ret;
469 if (afhi->seconds_total < 2 || !afhi->chunks_total)
470 return -E_MP3_INFO;
471 return 1;
472 }
473
474 static const char* mp3_suffixes[] = {"mp3", NULL};
475
476 /**
477 * the init function of the mp3 audio format handler
478 *
479 * \param afh pointer to the struct to initialize
480 */
481 void mp3_init(struct audio_format_handler *afh)
482 {
483 afh->get_file_info = mp3_get_file_info;
484 afh->suffixes = mp3_suffixes;
485 }