mp3_afh.c

   1 /*
   2  * Copyright (C) 2003-2008 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 "para.h"
  20 #include "error.h"
  21 #include "afh.h"
  22 #include "string.h"
  23 #include "afs.h"
  24 #include "server.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 static char *make_taginfo(char *title, char *artist, char *album, char *year,
  75                 char *comment)
  76 {
  77         return make_message("%s: %s, by %s\n" /* taginfo1 */
  78                 "%s: A: %s, Y: %s, C: %s\n", /* taginfo 2*/
  79                 status_item_list[SI_TAGINFO1],
  80                 (title && *title)? title : "(title tag not set)",
  81                 (artist && *artist)? artist : "(artist tag not set)",
  82                 status_item_list[SI_TAGINFO2],
  83                 (album && *album)?  album : "(album tag not set)",
  84                 (year && *year)? year : "????",
  85                 (comment && *comment)? comment : "(comment tag not set)"
  86         );
  87 }
  88
  89 #ifdef HAVE_LIBID3TAG
  90
  91 #include <id3tag.h>
  92
  93 static char *get_latin1(id3_ucs4_t const *string)
  94 {
  95         if (!string)
  96                 return NULL;
  97         return (char *)id3_ucs4_latin1duplicate(string);
  98 }
  99
 100 char *get_stringlist(union id3_field *field)
 101 {
 102         unsigned int k, nstrings = id3_field_getnstrings(field);
 103         char *result = NULL;
 104
 105         for (k = 0; k < nstrings; k++) {
 106                 char *tmp = (char *)get_latin1(id3_field_getstrings(field, k));
 107                 if (result) {
 108                         char *tmp2 = result;
 109                         result = make_message("%s %s", tmp2, tmp);
 110                         free(tmp);
 111                         free(tmp2);
 112                 } else
 113                         result = tmp;
 114         }
 115         return result;
 116 }
 117
 118 static char *get_string(union id3_field *field)
 119 {
 120         id3_ucs4_t const *string = id3_field_getfullstring(field);
 121
 122         return get_latin1(string);
 123 }
 124
 125 #define FOR_EACH_FIELD(f, j, fr) for (j = 0; j < (fr)->nfields && \
 126         (f = id3_frame_field((fr), j)); j++)
 127
 128 static char *get_strings(struct id3_frame *fr)
 129 {
 130         int j;
 131         union id3_field *field;
 132
 133         FOR_EACH_FIELD(field, j, fr) {
 134                 enum id3_field_type type = id3_field_type(field);
 135
 136                 if (type == ID3_FIELD_TYPE_STRINGLIST)
 137                         return get_stringlist(field);
 138                 if (type == ID3_FIELD_TYPE_STRINGFULL)
 139                         return get_string(field);
 140         }
 141         return NULL;
 142 }
 143
 144 static char *mp3_get_id3(__a_unused unsigned char *map,
 145                 __a_unused size_t numbytes, int fd)
 146 {
 147         int i;
 148         struct id3_tag *id3_t;
 149         char *title = NULL, *artist = NULL, *album = NULL, *year = NULL,
 150                 *comment = NULL, *result;
 151         struct id3_file *id3_f = id3_file_fdopen(fd, ID3_FILE_MODE_READONLY);
 152
 153         if (!id3_f)
 154                 goto no_tag;
 155         id3_t = id3_file_tag(id3_f);
 156         if (!id3_t)
 157                 goto no_tag;
 158         for (i = 0; i < id3_t->nframes; i++) {
 159                 struct id3_frame *fr = id3_t->frames[i];
 160                 if (!strcmp(fr->id, "TIT2")) {
 161                         if (!title)
 162                                 title = get_strings(fr);
 163                         continue;
 164                 }
 165                 if (!strcmp(fr->id, "TPE1")) {
 166                         if (!artist)
 167                                 artist = get_strings(fr);
 168                         continue;
 169                 }
 170                 if (!strcmp(fr->id, "TALB")) {
 171                         if (!album)
 172                                 album = get_strings(fr);
 173                         continue;
 174                 }
 175                 if (!strcmp(fr->id, "TDRC")) {
 176                         if (!year)
 177                                 year = get_strings(fr);
 178                         continue;
 179                 }
 180                 if (!strcmp(fr->id, "COMM")) {
 181                         if (!comment)
 182                                 comment = get_strings(fr);
 183                         continue;
 184                 }
 185         }
 186         id3_file_close(id3_f);
 187         result = make_taginfo(title, artist, album, year, comment);
 188         free(title);
 189         free(artist);
 190         free(album);
 191         free(year);
 192         free(comment);
 193         return result;
 194 no_tag:
 195         if (id3_f)
 196                 id3_file_close(id3_f);
 197         return make_message("%s: (no id3 v1/v2 tag)\n%s:\n",
 198                 status_item_list[SI_TAGINFO1],
 199                 status_item_list[SI_TAGINFO2]);
 200 }
 201
 202 #else /* HAVE_LIBID3TAG */
 203
 204 /*
 205  * Remove trailing whitespace from the end of a string
 206  */
 207 static char *unpad(char *string)
 208 {
 209         char *pos = string + strlen(string) - 1;
 210         while (para_isspace(pos[0]))
 211                 (pos--)[0] = 0;
 212         return string;
 213 }
 214
 215 static char *mp3_get_id3(unsigned char *map, size_t numbytes, __a_unused int fd)
 216 {
 217         char title[31], artist[31], album[31], year[5], comment[31];
 218         off_t fpos;
 219
 220         if (numbytes < 128 || strncmp("TAG", (char *)map + numbytes - 128, 3)) {
 221                 PARA_DEBUG_LOG("no id3 v1 tag\n");
 222                 return make_message("%s: (no id3 v1 tag)\n%s:\n",
 223                         status_item_list[SI_TAGINFO1],
 224                         status_item_list[SI_TAGINFO2]);
 225         }
 226         fpos = numbytes - 125;
 227         memcpy(title, map + fpos, 30);
 228         fpos += 30;
 229         title[30] = '\0';
 230         memcpy(artist, map + fpos, 30);
 231         fpos += 30;
 232         artist[30] = '\0';
 233         memcpy(album, map + fpos, 30);
 234         fpos += 30;
 235         album[30] = '\0';
 236         memcpy(year, map + fpos, 4);
 237         fpos += 4;
 238         year[4] = '\0';
 239         memcpy(comment, map + fpos, 30);
 240         comment[30] = '\0';
 241         unpad(title);
 242         unpad(artist);
 243         unpad(album);
 244         unpad(year);
 245         unpad(comment);
 246         return make_taginfo(title, artist, album, year, comment);
 247 }
 248 #endif /* HAVE_LIBID3TAG */
 249
 250 static int header_frequency(struct mp3header *h)
 251 {
 252         if (h->version > 2 || h->freq > 3)
 253                 return -E_HEADER_FREQ;
 254         return frequencies[h->version][h->freq];
 255 }
 256
 257 static const char *header_mode(struct mp3header *h)
 258 {
 259         if (h->mode > 4)
 260                 h->mode = 4; /* invalid */
 261         return mode_text[h->mode];
 262 }
 263
 264 static int header_channels(struct mp3header *h)
 265 {
 266         if (h->mode > 3)
 267                 return 0;
 268         if (h->mode < 3)
 269                 return 2;
 270         return 1;
 271 }
 272
 273 static int header_bitrate(struct mp3header *h)
 274 {
 275         if (!h->layer || h->layer > 3 || h->bitrate > 14 || !h->bitrate)
 276                 return -E_HEADER_BITRATE;
 277         return mp3info_bitrate[h->version & 1][3 - h->layer][h->bitrate - 1];
 278 }
 279
 280 static int frame_length(struct mp3header *header)
 281 {
 282         int hb, hf = header_frequency(header);
 283
 284         if (hf < 0)
 285                 return hf;
 286         hb = header_bitrate(header);
 287         if (hb < 0)
 288                 return hb;
 289         if (header->sync != 0xFFE || header->layer > 3)
 290                 return -E_FRAME;
 291         return frame_size_index[3 - header->layer] *
 292                 ((header->version & 1) + 1) * hb / hf
 293                 + header->padding;
 294 }
 295
 296 static int compare_headers(struct mp3header *h1,struct mp3header *h2)
 297 {
 298         if ((*(uint*)h1) == (*(uint*)h2))
 299                 return 1;
 300         if ((h1->version == h2->version) &&
 301                         (h1->layer == h2->layer) &&
 302                         (h1->crc == h2->crc) &&
 303                         (h1->freq == h2->freq) &&
 304                         (h1->mode == h2->mode) &&
 305                         (h1->copyright == h2->copyright) &&
 306                         (h1->original == h2->original) &&
 307                         (h1->emphasis == h2->emphasis))
 308                 return 1;
 309         return 0;
 310 }
 311
 312 /*
 313  * get next MP3 frame header.
 314  *
 315  * On success, the header frame length is returned and the given header
 316  * structure that is filled in.  A return value of zero means that we did not
 317  * retrieve a valid frame header, and a negative return value indicates an
 318  * error.
 319  */
 320 static int get_header(unsigned char *map, size_t numbytes, off_t *fpos,
 321         struct mp3header *header)
 322 {
 323         int fl, ret;
 324
 325         if (*fpos + FRAME_HEADER_SIZE > numbytes) {
 326                 *fpos = numbytes - 1;
 327                 header->sync = 0;
 328                 return 0;
 329         }
 330         header->layer = (map[*fpos + 1] >> 1) & 3;
 331         header->sync = (((int)map[*fpos]<<4) | ((int)(map[*fpos + 1]&0xE0)>>4));
 332         if (map[*fpos + 1] & 0x10)
 333                 header->version = (map[*fpos + 1] >> 3) & 1;
 334         else
 335                 header->version = 2;
 336         if ((header->sync != 0xFFE) || (header->layer != 1)) {
 337                 ret = 0;
 338                 header->sync = 0;
 339                 goto out;
 340         }
 341         header->crc = map[*fpos + 1] & 1;
 342         header->bitrate = (map[*fpos + 2] >> 4) & 0x0F;
 343         header->freq = (map[*fpos + 2] >> 2) & 0x3;
 344         header->padding = (map[*fpos + 2] >>1) & 0x1;
 345         header->mode = (map[*fpos + 3] >> 6) & 0x3;
 346         fl = frame_length(header);
 347         ret = (fl >= MIN_FRAME_SIZE)? fl : -E_FRAME_LENGTH;
 348 out:
 349         *fpos += FRAME_HEADER_SIZE;
 350         return ret;
 351 }
 352
 353 /*
 354  * find the next mp3 header
 355  *
 356  * Return the length of the next frame header or zero if the end of the file is
 357  * reached.
 358  */
 359 static int mp3_seek_next_header(unsigned char *map, size_t numbytes, off_t *fpos,
 360         struct mp3header *result)
 361 {
 362         int k, l = 0, first_len;
 363         struct mp3header h, h2;
 364         long valid_start = 0;
 365
 366         for (; *fpos < numbytes; (*fpos)++) {
 367                 if (map[*fpos] != 0xff)
 368                         continue;
 369                 valid_start = *fpos;
 370                 first_len = get_header(map, numbytes, fpos, &h);
 371                 if (first_len <= 0)
 372                         continue;
 373                 *fpos += first_len - FRAME_HEADER_SIZE;
 374                 for (k = 1; k < MIN_CONSEC_GOOD_FRAMES; k++) {
 375                         if ((l = get_header(map, numbytes, fpos, &h2)) <= 0)
 376                                 break;
 377                         if (!compare_headers(&h, &h2))
 378                                 break;
 379                         *fpos += l - FRAME_HEADER_SIZE;
 380                 }
 381                 if (k == MIN_CONSEC_GOOD_FRAMES) {
 382                         *fpos = valid_start;
 383                         *result = h2;
 384                         return first_len;
 385                 }
 386         }
 387         return 0;
 388 }
 389
 390 static int find_valid_start(unsigned char *map, size_t numbytes, off_t *fpos,
 391         struct mp3header *header)
 392 {
 393         int frame_len;
 394
 395         frame_len = get_header(map, numbytes, fpos, header);
 396         if (frame_len < 0)
 397                 return frame_len;
 398         if (!frame_len) {
 399                 frame_len = mp3_seek_next_header(map, numbytes, fpos, header);
 400                 if (frame_len <= 0)
 401                         return frame_len;
 402         } else
 403                 *fpos -= FRAME_HEADER_SIZE;
 404         if (frame_len <= 1)
 405                 return -E_FRAME_LENGTH;
 406         return frame_len;
 407 }
 408
 409 static int mp3_read_info(unsigned char *map, size_t numbytes, int fd,
 410                 struct afh_info *afhi)
 411 {
 412         long freq_avg = 0, br_avg = 0;
 413         int ret, len = 0, old_br = -1, vbr = 0;
 414         struct timeval total_time = {0, 0};
 415         unsigned chunk_table_size = 1000; /* gets increased on demand */
 416         off_t fpos = 0;
 417         struct mp3header header;
 418         char *taginfo;
 419
 420         afhi->chunks_total = 0;
 421         afhi->chunk_table = para_malloc(chunk_table_size * sizeof(size_t));
 422         taginfo = mp3_get_id3(map, numbytes, fd);
 423         while (1) {
 424                 unsigned long freq, br, fl;
 425                 struct timeval tmp, cct; /* current chunk time */
 426                 fpos += len;
 427                 len = find_valid_start(map, numbytes, &fpos, &header);
 428                 if (len <= 0)
 429                         break;
 430                 ret = header_frequency(&header);
 431                 if (ret < 0)
 432                         continue;
 433                 freq = ret;
 434                 ret = header_bitrate(&header);
 435                 if (ret < 0)
 436                         continue;
 437                 br = ret;
 438                 ret = frame_length(&header);
 439                 if (ret < 0)
 440                         continue;
 441                 fl = ret;
 442                 tmp.tv_sec = fl;
 443                 tmp.tv_usec = 0;
 444                 tv_divide(br * 125, &tmp, &cct);
 445                 tv_add(&cct, &total_time, &tmp);
 446                 total_time = tmp;
 447                 //PARA_DEBUG_LOG("%s: br: %d, freq: %d, fl: %d, cct: %lu\n", __func__, br, freq, fl, cct.tv_usec);
 448                 if (afhi->chunks_total >= chunk_table_size) {
 449                         chunk_table_size *= 2;
 450                         afhi->chunk_table = para_realloc(afhi->chunk_table,
 451                                 chunk_table_size * sizeof(size_t));
 452                 }
 453                 afhi->chunk_table[afhi->chunks_total] = fpos;
 454 //              if (afhi->chunks_total < 10 || !(afhi->chunks_total % 1000))
 455 //                      PARA_INFO_LOG("chunk #%lu: %zd\n", afhi->chunks_total,
 456 //                              afhi->chunk_table[afhi->chunks_total]);
 457                 afhi->chunks_total++;
 458                 if (afhi->chunks_total == 1) {
 459                         freq_avg = freq;
 460                         br_avg = br;
 461                         old_br = br;
 462                         continue;
 463                 }
 464                 freq_avg += ((long)freq - freq_avg) / ((long)afhi->chunks_total + 1);
 465                 br_avg += ((long)br - br_avg) / ((long)afhi->chunks_total + 1);
 466                 if (old_br != br)
 467                         vbr = 1;
 468                 old_br = br;
 469         }
 470         ret = -E_MP3_INFO;
 471         if (!afhi->chunks_total || !freq_avg || !br_avg)
 472                 goto err_out;
 473         afhi->chunk_table[afhi->chunks_total] = numbytes - 1;
 474         afhi->bitrate = br_avg;
 475         afhi->frequency = freq_avg;
 476         afhi->channels = header_channels(&header);
 477         afhi->seconds_total = (tv2ms(&total_time) + 500) / 1000;
 478         tv_divide(afhi->chunks_total, &total_time, &afhi->chunk_tv);
 479         PARA_DEBUG_LOG("%lu chunks, each %lums\n", afhi->chunks_total,
 480                 tv2ms(&afhi->chunk_tv));
 481         tv_scale(3, &afhi->chunk_tv, &afhi->eof_tv);
 482         PARA_DEBUG_LOG("eof timeout: %lu\n", tv2ms(&afhi->eof_tv));
 483         afhi->info_string = make_message("%s: %cbr, %s\n%s",
 484                 status_item_list[SI_AUDIO_FILE_INFO], vbr? 'v' : 'c',
 485                 header_mode(&header), taginfo);
 486         free(taginfo);
 487         return 1;
 488 err_out:
 489         free(taginfo);
 490         PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 491         free(afhi->chunk_table);
 492         return ret;
 493 }
 494
 495 /*
 496  * Read mp3 information from audio file
 497  */
 498 static int mp3_get_file_info(char *map, size_t numbytes, int fd,
 499                 struct afh_info *afhi)
 500 {
 501         int ret;
 502
 503         ret = mp3_read_info((unsigned char *)map, numbytes, fd, afhi);
 504         if (ret < 0)
 505                 return ret;
 506         if (afhi->seconds_total < 2 || !afhi->chunks_total)
 507                 return -E_MP3_INFO;
 508         return 1;
 509 }
 510
 511 static const char* mp3_suffixes[] = {"mp3", NULL};
 512
 513 /**
 514  * the init function of the mp3 audio format handler
 515  *
 516  * \param afh pointer to the struct to initialize
 517  */
 518 void mp3_init(struct audio_format_handler *afh)
 519 {
 520         afh->get_file_info = mp3_get_file_info;
 521         afh->suffixes = mp3_suffixes;
 522 }