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 #include "afs.h"
  25 #include "server.h"
  26
  27 /** \cond some defines and structs which are only used in this file */
  28
  29 /*
  30  * MIN_CONSEC_GOOD_FRAMES defines how many consecutive valid MP3 frames we need
  31  * to see before we decide we are looking at a real MP3 file
  32  */
  33 #define MIN_CONSEC_GOOD_FRAMES 4
  34 #define FRAME_HEADER_SIZE 4
  35 #define MIN_FRAME_SIZE 21
  36
  37 struct mp3header {
  38         unsigned long sync;
  39         unsigned int version;
  40         unsigned int layer;
  41         unsigned int crc;
  42         unsigned int bitrate;
  43         unsigned int freq;
  44         unsigned int padding;
  45         unsigned int mode;
  46         unsigned int copyright;
  47         unsigned int original;
  48         unsigned int emphasis;
  49 };
  50
  51 /** \endcond */
  52 static const int frequencies[3][4] = {
  53         {22050,24000,16000,50000}, /* MPEG 2.0 */
  54         {44100,48000,32000,50000}, /* MPEG 1.0 */
  55         {11025,12000,8000,50000} /* MPEG 2.5 */
  56 };
  57
  58 static const int mp3info_bitrate[2][3][14] = {
  59 { /* MPEG 2.0 */
  60         {32,48,56,64,80,96,112,128,144,160,176,192,224,256}, /* layer 1 */
  61         {8,16,24,32,40,48,56,64,80,96,112,128,144,160}, /* layer 2 */
  62         {8,16,24,32,40,48,56,64,80,96,112,128,144,160} /* layer 3 */
  63 },
  64
  65 { /* MPEG 1.0 */
  66         {32,64,96,128,160,192,224,256,288,320,352,384,416,448}, /* layer 1 */
  67         {32,48,56,64,80,96,112,128,160,192,224,256,320,384}, /* layer 2 */
  68         {32,40,48,56,64,80,96,112,128,160,192,224,256,320} /* layer 3 */
  69 }
  70 };
  71
  72 static const int frame_size_index[] = {24000, 72000, 72000};
  73 static const char *mode_text[] = {"stereo", "joint stereo", "dual channel", "mono", "invalid"};
  74
  75 #ifdef HAVE_LIBID3TAG
  76
  77 #include <id3tag.h>
  78
  79 static char *get_latin1(id3_ucs4_t const *string)
  80 {
  81         if (!string)
  82                 return NULL;
  83         return (char *)id3_ucs4_latin1duplicate(string);
  84 }
  85
  86 static char *get_stringlist(union id3_field *field)
  87 {
  88         unsigned int k, nstrings = id3_field_getnstrings(field);
  89         char *result = NULL;
  90
  91         for (k = 0; k < nstrings; k++) {
  92                 char *tmp = (char *)get_latin1(id3_field_getstrings(field, k));
  93                 if (result) {
  94                         char *tmp2 = result;
  95                         result = make_message("%s %s", tmp2, tmp);
  96                         free(tmp);
  97                         free(tmp2);
  98                 } else
  99                         result = tmp;
 100         }
 101         return result;
 102 }
 103
 104 static char *get_string(union id3_field *field)
 105 {
 106         id3_ucs4_t const *string = id3_field_getfullstring(field);
 107
 108         return get_latin1(string);
 109 }
 110
 111 #define FOR_EACH_FIELD(f, j, fr) for (j = 0; j < (fr)->nfields && \
 112         (f = id3_frame_field((fr), j)); j++)
 113
 114 static char *get_strings(struct id3_frame *fr)
 115 {
 116         int j;
 117         union id3_field *field;
 118
 119         FOR_EACH_FIELD(field, j, fr) {
 120                 enum id3_field_type type = id3_field_type(field);
 121
 122                 if (type == ID3_FIELD_TYPE_STRINGLIST)
 123                         return get_stringlist(field);
 124                 if (type == ID3_FIELD_TYPE_STRINGFULL)
 125                         return get_string(field);
 126         }
 127         return NULL;
 128 }
 129
 130 static char *mp3_get_id3(__a_unused unsigned char *map,
 131                 __a_unused size_t numbytes, int fd)
 132 {
 133         int i;
 134         struct id3_tag *id3_t;
 135         char *title = NULL, *artist = NULL, *album = NULL, *year = NULL,
 136                 *comment = NULL, *result;
 137         struct id3_file *id3_f = id3_file_fdopen(fd, ID3_FILE_MODE_READONLY);
 138
 139         if (!id3_f)
 140                 goto no_tag;
 141         id3_t = id3_file_tag(id3_f);
 142         if (!id3_t)
 143                 goto no_tag;
 144         for (i = 0; i < id3_t->nframes; i++) {
 145                 struct id3_frame *fr = id3_t->frames[i];
 146                 if (!strcmp(fr->id, "TIT2")) {
 147                         if (!title)
 148                                 title = get_strings(fr);
 149                         continue;
 150                 }
 151                 if (!strcmp(fr->id, "TPE1")) {
 152                         if (!artist)
 153                                 artist = get_strings(fr);
 154                         continue;
 155                 }
 156                 if (!strcmp(fr->id, "TALB")) {
 157                         if (!album)
 158                                 album = get_strings(fr);
 159                         continue;
 160                 }
 161                 if (!strcmp(fr->id, "TDRC")) {
 162                         if (!year)
 163                                 year = get_strings(fr);
 164                         continue;
 165                 }
 166                 if (!strcmp(fr->id, "COMM")) {
 167                         if (!comment)
 168                                 comment = get_strings(fr);
 169                         continue;
 170                 }
 171         }
 172         id3_file_close(id3_f);
 173         result = make_taginfo(title, artist, album, year, comment);
 174         free(title);
 175         free(artist);
 176         free(album);
 177         free(year);
 178         free(comment);
 179         return result;
 180 no_tag:
 181         if (id3_f)
 182                 id3_file_close(id3_f);
 183         return make_message("%s: (no id3 v1/v2 tag)\n%s:\n",
 184                 status_item_list[SI_TAGINFO1],
 185                 status_item_list[SI_TAGINFO2]);
 186 }
 187
 188 #else /* HAVE_LIBID3TAG */
 189
 190 /*
 191  * Remove trailing whitespace from the end of a string
 192  */
 193 static char *unpad(char *string)
 194 {
 195         char *pos = string + strlen(string) - 1;
 196         while (para_isspace(pos[0]))
 197                 (pos--)[0] = 0;
 198         return string;
 199 }
 200
 201 static char *mp3_get_id3(unsigned char *map, size_t numbytes, __a_unused int fd)
 202 {
 203         char title[31], artist[31], album[31], year[5], comment[31];
 204         off_t fpos;
 205
 206         if (numbytes < 128 || strncmp("TAG", (char *)map + numbytes - 128, 3)) {
 207                 PARA_DEBUG_LOG("no id3 v1 tag\n");
 208                 return make_message("%s: (no id3 v1 tag)\n%s:\n",
 209                         status_item_list[SI_TAGINFO1],
 210                         status_item_list[SI_TAGINFO2]);
 211         }
 212         fpos = numbytes - 125;
 213         memcpy(title, map + fpos, 30);
 214         fpos += 30;
 215         title[30] = '\0';
 216         memcpy(artist, map + fpos, 30);
 217         fpos += 30;
 218         artist[30] = '\0';
 219         memcpy(album, map + fpos, 30);
 220         fpos += 30;
 221         album[30] = '\0';
 222         memcpy(year, map + fpos, 4);
 223         fpos += 4;
 224         year[4] = '\0';
 225         memcpy(comment, map + fpos, 30);
 226         comment[30] = '\0';
 227         unpad(title);
 228         unpad(artist);
 229         unpad(album);
 230         unpad(year);
 231         unpad(comment);
 232         return make_taginfo(title, artist, album, year, comment);
 233 }
 234 #endif /* HAVE_LIBID3TAG */
 235
 236 static int header_frequency(struct mp3header *h)
 237 {
 238         if (h->version > 2 || h->freq > 3)
 239                 return -E_HEADER_FREQ;
 240         return frequencies[h->version][h->freq];
 241 }
 242
 243 static const char *header_mode(struct mp3header *h)
 244 {
 245         if (h->mode > 4)
 246                 h->mode = 4; /* invalid */
 247         return mode_text[h->mode];
 248 }
 249
 250 static int header_channels(struct mp3header *h)
 251 {
 252         if (h->mode > 3)
 253                 return 0;
 254         if (h->mode < 3)
 255                 return 2;
 256         return 1;
 257 }
 258
 259 static int header_bitrate(struct mp3header *h)
 260 {
 261         if (!h->layer || h->layer > 3 || h->bitrate > 14 || !h->bitrate)
 262                 return -E_HEADER_BITRATE;
 263         return mp3info_bitrate[h->version & 1][3 - h->layer][h->bitrate - 1];
 264 }
 265
 266 static int frame_length(struct mp3header *header)
 267 {
 268         int hb, hf = header_frequency(header);
 269
 270         if (hf < 0)
 271                 return hf;
 272         hb = header_bitrate(header);
 273         if (hb < 0)
 274                 return hb;
 275         if (header->sync != 0xFFE || header->layer > 3)
 276                 return -E_FRAME;
 277         return frame_size_index[3 - header->layer] *
 278                 ((header->version & 1) + 1) * hb / hf
 279                 + header->padding;
 280 }
 281
 282 static int compare_headers(struct mp3header *h1,struct mp3header *h2)
 283 {
 284         if ((*(unsigned int*)h1) == (*(unsigned int*)h2))
 285                 return 1;
 286         if ((h1->version == h2->version) &&
 287                         (h1->layer == h2->layer) &&
 288                         (h1->crc == h2->crc) &&
 289                         (h1->freq == h2->freq) &&
 290                         (h1->mode == h2->mode) &&
 291                         (h1->copyright == h2->copyright) &&
 292                         (h1->original == h2->original) &&
 293                         (h1->emphasis == h2->emphasis))
 294                 return 1;
 295         return 0;
 296 }
 297
 298 /*
 299  * get next MP3 frame header.
 300  *
 301  * On success, the header frame length is returned and the given header
 302  * structure that is filled in.  A return value of zero means that we did not
 303  * retrieve a valid frame header, and a negative return value indicates an
 304  * error.
 305  */
 306 static int get_header(unsigned char *map, size_t numbytes, off_t *fpos,
 307         struct mp3header *header)
 308 {
 309         int fl, ret;
 310
 311         if (*fpos + FRAME_HEADER_SIZE > numbytes) {
 312                 *fpos = numbytes - 1;
 313                 header->sync = 0;
 314                 return 0;
 315         }
 316         header->layer = (map[*fpos + 1] >> 1) & 3;
 317         header->sync = (((int)map[*fpos]<<4) | ((int)(map[*fpos + 1]&0xE0)>>4));
 318         if (map[*fpos + 1] & 0x10)
 319                 header->version = (map[*fpos + 1] >> 3) & 1;
 320         else
 321                 header->version = 2;
 322         if ((header->sync != 0xFFE) || (header->layer != 1)) {
 323                 ret = 0;
 324                 header->sync = 0;
 325                 goto out;
 326         }
 327         header->crc = map[*fpos + 1] & 1;
 328         header->bitrate = (map[*fpos + 2] >> 4) & 0x0F;
 329         header->freq = (map[*fpos + 2] >> 2) & 0x3;
 330         header->padding = (map[*fpos + 2] >>1) & 0x1;
 331         header->mode = (map[*fpos + 3] >> 6) & 0x3;
 332         fl = frame_length(header);
 333         ret = (fl >= MIN_FRAME_SIZE)? fl : -E_FRAME_LENGTH;
 334 out:
 335         *fpos += FRAME_HEADER_SIZE;
 336         return ret;
 337 }
 338
 339 /*
 340  * find the next mp3 header
 341  *
 342  * Return the length of the next frame header or zero if the end of the file is
 343  * reached.
 344  */
 345 static int mp3_seek_next_header(unsigned char *map, size_t numbytes, off_t *fpos,
 346         struct mp3header *result)
 347 {
 348         int k, l = 0, first_len;
 349         struct mp3header h, h2;
 350         long valid_start = 0;
 351
 352         for (; *fpos < numbytes; (*fpos)++) {
 353                 if (map[*fpos] != 0xff)
 354                         continue;
 355                 valid_start = *fpos;
 356                 first_len = get_header(map, numbytes, fpos, &h);
 357                 if (first_len <= 0)
 358                         continue;
 359                 *fpos += first_len - FRAME_HEADER_SIZE;
 360                 for (k = 1; k < MIN_CONSEC_GOOD_FRAMES; k++) {
 361                         if ((l = get_header(map, numbytes, fpos, &h2)) <= 0)
 362                                 break;
 363                         if (!compare_headers(&h, &h2))
 364                                 break;
 365                         *fpos += l - FRAME_HEADER_SIZE;
 366                 }
 367                 if (k == MIN_CONSEC_GOOD_FRAMES) {
 368                         *fpos = valid_start;
 369                         *result = h2;
 370                         return first_len;
 371                 }
 372         }
 373         return 0;
 374 }
 375
 376 static int find_valid_start(unsigned char *map, size_t numbytes, off_t *fpos,
 377         struct mp3header *header)
 378 {
 379         int frame_len;
 380
 381         frame_len = get_header(map, numbytes, fpos, header);
 382         if (frame_len < 0)
 383                 return frame_len;
 384         if (!frame_len) {
 385                 frame_len = mp3_seek_next_header(map, numbytes, fpos, header);
 386                 if (frame_len <= 0)
 387                         return frame_len;
 388         } else
 389                 *fpos -= FRAME_HEADER_SIZE;
 390         if (frame_len <= 1)
 391                 return -E_FRAME_LENGTH;
 392         return frame_len;
 393 }
 394
 395 static int mp3_read_info(unsigned char *map, size_t numbytes, int fd,
 396                 struct afh_info *afhi)
 397 {
 398         uint64_t freq_sum = 0, br_sum = 0;
 399         int fl = 0, ret, len = 0, old_br = -1, vbr = 0;
 400         struct timeval total_time = {0, 0};
 401         unsigned chunk_table_size = 1000; /* gets increased on demand */
 402         off_t fpos = 0;
 403         struct mp3header header;
 404         char *taginfo;
 405
 406         afhi->chunks_total = 0;
 407         afhi->chunk_table = para_malloc(chunk_table_size * sizeof(uint32_t));
 408         taginfo = mp3_get_id3(map, numbytes, fd);
 409         while (1) {
 410                 int freq, br;
 411                 struct timeval tmp, cct; /* current chunk time */
 412                 fpos += len;
 413                 len = find_valid_start(map, numbytes, &fpos, &header);
 414                 if (len <= 0) {
 415                         size_t end;
 416                         ret = -E_MP3_INFO;
 417                         if (!afhi->chunks_total)
 418                                 goto err_out;
 419                         end = afhi->chunk_table[afhi->chunks_total - 1] + fl;
 420                         afhi->chunk_table[afhi->chunks_total]
 421                                 = PARA_MIN(end, numbytes);
 422                         break;
 423                 }
 424                 ret = header_frequency(&header);
 425                 if (ret < 0)
 426                         continue;
 427                 freq = ret;
 428                 ret = header_bitrate(&header);
 429                 if (ret < 0)
 430                         continue;
 431                 br = ret;
 432                 ret = frame_length(&header);
 433                 if (ret < 0)
 434                         continue;
 435                 fl = ret;
 436                 tmp.tv_sec = fl;
 437                 tmp.tv_usec = 0;
 438                 tv_divide(br * 125, &tmp, &cct);
 439                 tv_add(&cct, &total_time, &tmp);
 440                 total_time = tmp;
 441                 if (afhi->chunks_total >= chunk_table_size) {
 442                         chunk_table_size *= 2;
 443                         afhi->chunk_table = para_realloc(afhi->chunk_table,
 444                                 chunk_table_size * sizeof(uint32_t));
 445                 }
 446                 afhi->chunk_table[afhi->chunks_total] = fpos;
 447                 afhi->chunks_total++;
 448                 freq_sum += freq;
 449                 br_sum += br;
 450                 if (afhi->chunks_total != 1 && old_br != br)
 451                         vbr = 1;
 452                 old_br = br;
 453         }
 454         ret = -E_MP3_INFO;
 455         if (!freq_sum || !br_sum)
 456                 goto err_out;
 457         afhi->bitrate = br_sum / afhi->chunks_total;
 458         afhi->frequency = freq_sum / afhi->chunks_total;
 459         afhi->channels = header_channels(&header);
 460         afhi->seconds_total = (tv2ms(&total_time) + 500) / 1000;
 461         tv_divide(afhi->chunks_total, &total_time, &afhi->chunk_tv);
 462         PARA_DEBUG_LOG("%lu chunks, each %lums\n", afhi->chunks_total,
 463                 tv2ms(&afhi->chunk_tv));
 464         tv_scale(3, &afhi->chunk_tv, &afhi->eof_tv);
 465         PARA_DEBUG_LOG("eof timeout: %lu\n", tv2ms(&afhi->eof_tv));
 466         afhi->info_string = make_message("%s: %cbr, %s\n%s",
 467                 status_item_list[SI_AUDIO_FILE_INFO], vbr? 'v' : 'c',
 468                 header_mode(&header), taginfo);
 469         free(taginfo);
 470         return 1;
 471 err_out:
 472         free(taginfo);
 473         PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 474         free(afhi->chunk_table);
 475         return ret;
 476 }
 477
 478 /*
 479  * Read mp3 information from audio file
 480  */
 481 static int mp3_get_file_info(char *map, size_t numbytes, int fd,
 482                 struct afh_info *afhi)
 483 {
 484         int ret;
 485
 486         ret = mp3_read_info((unsigned char *)map, numbytes, fd, afhi);
 487         if (ret < 0)
 488                 return ret;
 489         if (afhi->seconds_total < 2 || !afhi->chunks_total)
 490                 return -E_MP3_INFO;
 491         return 1;
 492 }
 493
 494 static const char* mp3_suffixes[] = {"mp3", NULL};
 495
 496 /**
 497  * the init function of the mp3 audio format handler
 498  *
 499  * \param afh pointer to the struct to initialize
 500  */
 501 void mp3_init(struct audio_format_handler *afh)
 502 {
 503         afh->get_file_info = mp3_get_file_info;
 504         afh->suffixes = mp3_suffixes;
 505 }