libavformat/mp3.c

   1 /*
   2  * MP3 muxer and demuxer
   3  * Copyright (c) 2003 Fabrice Bellard
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include <strings.h>
  23 #include "libavutil/avstring.h"
  24 #include "libavcodec/mpegaudio.h"
  25 #include "libavcodec/mpegaudiodecheader.h"
  26 #include "avformat.h"
  27 #include "id3v2.h"
  28
  29 #define ID3v1_TAG_SIZE 128
  30
  31 #define ID3v1_GENRE_MAX 125
  32
  33 static const char * const id3v1_genre_str[ID3v1_GENRE_MAX + 1] = {
  34     [0] = "Blues",
  35     [1] = "Classic Rock",
  36     [2] = "Country",
  37     [3] = "Dance",
  38     [4] = "Disco",
  39     [5] = "Funk",
  40     [6] = "Grunge",
  41     [7] = "Hip-Hop",
  42     [8] = "Jazz",
  43     [9] = "Metal",
  44     [10] = "New Age",
  45     [11] = "Oldies",
  46     [12] = "Other",
  47     [13] = "Pop",
  48     [14] = "R&B",
  49     [15] = "Rap",
  50     [16] = "Reggae",
  51     [17] = "Rock",
  52     [18] = "Techno",
  53     [19] = "Industrial",
  54     [20] = "Alternative",
  55     [21] = "Ska",
  56     [22] = "Death Metal",
  57     [23] = "Pranks",
  58     [24] = "Soundtrack",
  59     [25] = "Euro-Techno",
  60     [26] = "Ambient",
  61     [27] = "Trip-Hop",
  62     [28] = "Vocal",
  63     [29] = "Jazz+Funk",
  64     [30] = "Fusion",
  65     [31] = "Trance",
  66     [32] = "Classical",
  67     [33] = "Instrumental",
  68     [34] = "Acid",
  69     [35] = "House",
  70     [36] = "Game",
  71     [37] = "Sound Clip",
  72     [38] = "Gospel",
  73     [39] = "Noise",
  74     [40] = "AlternRock",
  75     [41] = "Bass",
  76     [42] = "Soul",
  77     [43] = "Punk",
  78     [44] = "Space",
  79     [45] = "Meditative",
  80     [46] = "Instrumental Pop",
  81     [47] = "Instrumental Rock",
  82     [48] = "Ethnic",
  83     [49] = "Gothic",
  84     [50] = "Darkwave",
  85     [51] = "Techno-Industrial",
  86     [52] = "Electronic",
  87     [53] = "Pop-Folk",
  88     [54] = "Eurodance",
  89     [55] = "Dream",
  90     [56] = "Southern Rock",
  91     [57] = "Comedy",
  92     [58] = "Cult",
  93     [59] = "Gangsta",
  94     [60] = "Top 40",
  95     [61] = "Christian Rap",
  96     [62] = "Pop/Funk",
  97     [63] = "Jungle",
  98     [64] = "Native American",
  99     [65] = "Cabaret",
 100     [66] = "New Wave",
 101     [67] = "Psychadelic",
 102     [68] = "Rave",
 103     [69] = "Showtunes",
 104     [70] = "Trailer",
 105     [71] = "Lo-Fi",
 106     [72] = "Tribal",
 107     [73] = "Acid Punk",
 108     [74] = "Acid Jazz",
 109     [75] = "Polka",
 110     [76] = "Retro",
 111     [77] = "Musical",
 112     [78] = "Rock & Roll",
 113     [79] = "Hard Rock",
 114     [80] = "Folk",
 115     [81] = "Folk-Rock",
 116     [82] = "National Folk",
 117     [83] = "Swing",
 118     [84] = "Fast Fusion",
 119     [85] = "Bebob",
 120     [86] = "Latin",
 121     [87] = "Revival",
 122     [88] = "Celtic",
 123     [89] = "Bluegrass",
 124     [90] = "Avantgarde",
 125     [91] = "Gothic Rock",
 126     [92] = "Progressive Rock",
 127     [93] = "Psychedelic Rock",
 128     [94] = "Symphonic Rock",
 129     [95] = "Slow Rock",
 130     [96] = "Big Band",
 131     [97] = "Chorus",
 132     [98] = "Easy Listening",
 133     [99] = "Acoustic",
 134     [100] = "Humour",
 135     [101] = "Speech",
 136     [102] = "Chanson",
 137     [103] = "Opera",
 138     [104] = "Chamber Music",
 139     [105] = "Sonata",
 140     [106] = "Symphony",
 141     [107] = "Booty Bass",
 142     [108] = "Primus",
 143     [109] = "Porn Groove",
 144     [110] = "Satire",
 145     [111] = "Slow Jam",
 146     [112] = "Club",
 147     [113] = "Tango",
 148     [114] = "Samba",
 149     [115] = "Folklore",
 150     [116] = "Ballad",
 151     [117] = "Power Ballad",
 152     [118] = "Rhythmic Soul",
 153     [119] = "Freestyle",
 154     [120] = "Duet",
 155     [121] = "Punk Rock",
 156     [122] = "Drum Solo",
 157     [123] = "A capella",
 158     [124] = "Euro-House",
 159     [125] = "Dance Hall",
 160 };
 161
 162 static unsigned int id3v2_get_size(ByteIOContext *s, int len)
 163 {
 164     int v=0;
 165     while(len--)
 166         v= (v<<7) + (get_byte(s)&0x7F);
 167     return v;
 168 }
 169
 170 static void id3v2_read_ttag(AVFormatContext *s, int taglen, const char *key)
 171 {
 172     char *q, dst[512];
 173     int len, dstlen = sizeof(dst) - 1;
 174     unsigned genre;
 175
 176     dst[0]= 0;
 177     if(taglen < 1)
 178         return;
 179
 180     taglen--; /* account for encoding type byte */
 181
 182     switch(get_byte(s->pb)) { /* encoding type */
 183
 184     case 0:  /* ISO-8859-1 (0 - 255 maps directly into unicode) */
 185         q = dst;
 186         while(taglen--) {
 187             uint8_t tmp;
 188             PUT_UTF8(get_byte(s->pb), tmp, if (q - dst < dstlen - 1) *q++ = tmp;)
 189         }
 190         *q = '\0';
 191         break;
 192
 193     case 3:  /* UTF-8 */
 194         len = FFMIN(taglen, dstlen-1);
 195         get_buffer(s->pb, dst, len);
 196         dst[len] = 0;
 197         break;
 198     }
 199
 200     if (!strcmp(key, "genre")
 201         && sscanf(dst, "(%d)", &genre) == 1 && genre <= ID3v1_GENRE_MAX)
 202         av_strlcpy(dst, id3v1_genre_str[genre], sizeof(dst));
 203
 204     if (*dst)
 205         av_metadata_set(&s->metadata, key, dst);
 206 }
 207
 208 /**
 209  * ID3v2 parser
 210  *
 211  * Handles ID3v2.2, 2.3 and 2.4.
 212  *
 213  */
 214
 215 static void id3v2_parse(AVFormatContext *s, int len, uint8_t version, uint8_t flags)
 216 {
 217     int isv34, tlen;
 218     uint32_t tag;
 219     int64_t next;
 220     int taghdrlen;
 221     const char *reason;
 222
 223     switch(version) {
 224     case 2:
 225         if(flags & 0x40) {
 226             reason = "compression";
 227             goto error;
 228         }
 229         isv34 = 0;
 230         taghdrlen = 6;
 231         break;
 232
 233     case 3:
 234     case 4:
 235         isv34 = 1;
 236         taghdrlen = 10;
 237         break;
 238
 239     default:
 240         reason = "version";
 241         goto error;
 242     }
 243
 244     if(flags & 0x80) {
 245         reason = "unsynchronization";
 246         goto error;
 247     }
 248
 249     if(isv34 && flags & 0x40) /* Extended header present, just skip over it */
 250         url_fskip(s->pb, id3v2_get_size(s->pb, 4));
 251
 252     while(len >= taghdrlen) {
 253         if(isv34) {
 254             tag  = get_be32(s->pb);
 255             tlen = id3v2_get_size(s->pb, 4);
 256             get_be16(s->pb); /* flags */
 257         } else {
 258             tag  = get_be24(s->pb);
 259             tlen = id3v2_get_size(s->pb, 3);
 260         }
 261         len -= taghdrlen + tlen;
 262
 263         if(len < 0)
 264             break;
 265
 266         next = url_ftell(s->pb) + tlen;
 267
 268         switch(tag) {
 269         case MKBETAG('T', 'I', 'T', '2'):
 270         case MKBETAG(0,   'T', 'T', '2'):
 271             id3v2_read_ttag(s, tlen, "title");
 272             break;
 273         case MKBETAG('T', 'P', 'E', '1'):
 274         case MKBETAG(0,   'T', 'P', '1'):
 275             id3v2_read_ttag(s, tlen, "author");
 276             break;
 277         case MKBETAG('T', 'A', 'L', 'B'):
 278         case MKBETAG(0,   'T', 'A', 'L'):
 279             id3v2_read_ttag(s, tlen, "album");
 280             break;
 281         case MKBETAG('T', 'C', 'O', 'N'):
 282         case MKBETAG(0,   'T', 'C', 'O'):
 283             id3v2_read_ttag(s, tlen, "genre");
 284             break;
 285         case MKBETAG('T', 'C', 'O', 'P'):
 286         case MKBETAG(0,   'T', 'C', 'R'):
 287             id3v2_read_ttag(s, tlen, "copyright");
 288             break;
 289         case MKBETAG('T', 'R', 'C', 'K'):
 290         case MKBETAG(0,   'T', 'R', 'K'):
 291             id3v2_read_ttag(s, tlen, "track");
 292             break;
 293         case 0:
 294             /* padding, skip to end */
 295             url_fskip(s->pb, len);
 296             len = 0;
 297             continue;
 298         }
 299         /* Skip to end of tag */
 300         url_fseek(s->pb, next, SEEK_SET);
 301     }
 302
 303     if(version == 4 && flags & 0x10) /* Footer preset, always 10 bytes, skip over it */
 304         url_fskip(s->pb, 10);
 305     return;
 306
 307   error:
 308     av_log(s, AV_LOG_INFO, "ID3v2.%d tag skipped, cannot handle %s\n", version, reason);
 309     url_fskip(s->pb, len);
 310 }
 311
 312 static void id3v1_get_string(AVFormatContext *s, const char *key,
 313                              const uint8_t *buf, int buf_size)
 314 {
 315     int i, c;
 316     char *q, str[512];
 317
 318     q = str;
 319     for(i = 0; i < buf_size; i++) {
 320         c = buf[i];
 321         if (c == '\0')
 322             break;
 323         if ((q - str) >= sizeof(str) - 1)
 324             break;
 325         *q++ = c;
 326     }
 327     *q = '\0';
 328
 329     if (*str)
 330         av_metadata_set(&s->metadata, key, str);
 331 }
 332
 333 /* 'buf' must be ID3v1_TAG_SIZE byte long */
 334 static int id3v1_parse_tag(AVFormatContext *s, const uint8_t *buf)
 335 {
 336     char str[5];
 337     int genre;
 338
 339     if (!(buf[0] == 'T' &&
 340           buf[1] == 'A' &&
 341           buf[2] == 'G'))
 342         return -1;
 343     id3v1_get_string(s, "title",   buf +  3, 30);
 344     id3v1_get_string(s, "author",  buf + 33, 30);
 345     id3v1_get_string(s, "album",   buf + 63, 30);
 346     id3v1_get_string(s, "year",    buf + 93,  4);
 347     id3v1_get_string(s, "comment", buf + 97, 30);
 348     if (buf[125] == 0 && buf[126] != 0) {
 349         snprintf(str, sizeof(str), "%d", buf[126]);
 350         av_metadata_set(&s->metadata, "track", str);
 351     }
 352     genre = buf[127];
 353     if (genre <= ID3v1_GENRE_MAX)
 354         av_metadata_set(&s->metadata, "genre", id3v1_genre_str[genre]);
 355     return 0;
 356 }
 357
 358 /* mp3 read */
 359
 360 static int mp3_read_probe(AVProbeData *p)
 361 {
 362     int max_frames, first_frames = 0;
 363     int fsize, frames, sample_rate;
 364     uint32_t header;
 365     uint8_t *buf, *buf0, *buf2, *end;
 366     AVCodecContext avctx;
 367
 368     buf0 = p->buf;
 369     if(ff_id3v2_match(buf0)) {
 370         buf0 += ff_id3v2_tag_len(buf0);
 371     }
 372
 373     max_frames = 0;
 374     buf = buf0;
 375     end = p->buf + p->buf_size - sizeof(uint32_t);
 376
 377     for(; buf < end; buf= buf2+1) {
 378         buf2 = buf;
 379
 380         for(frames = 0; buf2 < end; frames++) {
 381             header = AV_RB32(buf2);
 382             fsize = ff_mpa_decode_header(&avctx, header, &sample_rate, &sample_rate, &sample_rate, &sample_rate);
 383             if(fsize < 0)
 384                 break;
 385             buf2 += fsize;
 386         }
 387         max_frames = FFMAX(max_frames, frames);
 388         if(buf == buf0)
 389             first_frames= frames;
 390     }
 391     if   (first_frames>=3) return AVPROBE_SCORE_MAX/2+1;
 392     else if(max_frames>500)return AVPROBE_SCORE_MAX/2;
 393     else if(max_frames>=3) return AVPROBE_SCORE_MAX/4;
 394     else if(buf0!=p->buf)  return AVPROBE_SCORE_MAX/4-1;
 395     else if(max_frames>=1) return 1;
 396     else                   return 0;
 397 }
 398
 399 /**
 400  * Try to find Xing/Info/VBRI tags and compute duration from info therein
 401  */
 402 static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
 403 {
 404     uint32_t v, spf;
 405     int frames = -1; /* Total number of frames in file */
 406     const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}};
 407     MPADecodeHeader c;
 408     int vbrtag_size = 0;
 409
 410     v = get_be32(s->pb);
 411     if(ff_mpa_check_header(v) < 0)
 412       return -1;
 413
 414     if (ff_mpegaudio_decode_header(&c, v) == 0)
 415         vbrtag_size = c.frame_size;
 416     if(c.layer != 3)
 417         return -1;
 418
 419     /* Check for Xing / Info tag */
 420     url_fseek(s->pb, xing_offtbl[c.lsf == 1][c.nb_channels == 1], SEEK_CUR);
 421     v = get_be32(s->pb);
 422     if(v == MKBETAG('X', 'i', 'n', 'g') || v == MKBETAG('I', 'n', 'f', 'o')) {
 423         v = get_be32(s->pb);
 424         if(v & 0x1)
 425             frames = get_be32(s->pb);
 426     }
 427
 428     /* Check for VBRI tag (always 32 bytes after end of mpegaudio header) */
 429     url_fseek(s->pb, base + 4 + 32, SEEK_SET);
 430     v = get_be32(s->pb);
 431     if(v == MKBETAG('V', 'B', 'R', 'I')) {
 432         /* Check tag version */
 433         if(get_be16(s->pb) == 1) {
 434             /* skip delay, quality and total bytes */
 435             url_fseek(s->pb, 8, SEEK_CUR);
 436             frames = get_be32(s->pb);
 437         }
 438     }
 439
 440     if(frames < 0)
 441         return -1;
 442
 443     /* Skip the vbr tag frame */
 444     url_fseek(s->pb, base + vbrtag_size, SEEK_SET);
 445
 446     spf = c.lsf ? 576 : 1152; /* Samples per frame, layer 3 */
 447     st->duration = av_rescale_q(frames, (AVRational){spf, c.sample_rate},
 448                                 st->time_base);
 449     return 0;
 450 }
 451
 452 static int mp3_read_header(AVFormatContext *s,
 453                            AVFormatParameters *ap)
 454 {
 455     AVStream *st;
 456     uint8_t buf[ID3v1_TAG_SIZE];
 457     int len, ret, filesize;
 458     int64_t off;
 459
 460     st = av_new_stream(s, 0);
 461     if (!st)
 462         return AVERROR(ENOMEM);
 463
 464     st->codec->codec_type = CODEC_TYPE_AUDIO;
 465     st->codec->codec_id = CODEC_ID_MP3;
 466     st->need_parsing = AVSTREAM_PARSE_FULL;
 467     st->start_time = 0;
 468
 469     /* try to get the TAG */
 470     if (!url_is_streamed(s->pb)) {
 471         /* XXX: change that */
 472         filesize = url_fsize(s->pb);
 473         if (filesize > 128) {
 474             url_fseek(s->pb, filesize - 128, SEEK_SET);
 475             ret = get_buffer(s->pb, buf, ID3v1_TAG_SIZE);
 476             if (ret == ID3v1_TAG_SIZE) {
 477                 id3v1_parse_tag(s, buf);
 478             }
 479             url_fseek(s->pb, 0, SEEK_SET);
 480         }
 481     }
 482
 483     /* if ID3v2 header found, skip it */
 484     ret = get_buffer(s->pb, buf, ID3v2_HEADER_SIZE);
 485     if (ret != ID3v2_HEADER_SIZE)
 486         return -1;
 487     if (ff_id3v2_match(buf)) {
 488         /* parse ID3v2 header */
 489         len = ((buf[6] & 0x7f) << 21) |
 490             ((buf[7] & 0x7f) << 14) |
 491             ((buf[8] & 0x7f) << 7) |
 492             (buf[9] & 0x7f);
 493         id3v2_parse(s, len, buf[3], buf[5]);
 494     } else {
 495         url_fseek(s->pb, 0, SEEK_SET);
 496     }
 497
 498     off = url_ftell(s->pb);
 499     if (mp3_parse_vbr_tags(s, st, off) < 0)
 500         url_fseek(s->pb, off, SEEK_SET);
 501
 502     /* the parameters will be extracted from the compressed bitstream */
 503     return 0;
 504 }
 505
 506 #define MP3_PACKET_SIZE 1024
 507
 508 static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt)
 509 {
 510     int ret, size;
 511     //    AVStream *st = s->streams[0];
 512
 513     size= MP3_PACKET_SIZE;
 514
 515     ret= av_get_packet(s->pb, pkt, size);
 516
 517     pkt->stream_index = 0;
 518     if (ret <= 0) {
 519         return AVERROR(EIO);
 520     }
 521     /* note: we need to modify the packet size here to handle the last
 522        packet */
 523     pkt->size = ret;
 524     return ret;
 525 }
 526
 527 #if CONFIG_MP2_MUXER || CONFIG_MP3_MUXER
 528 static int id3v1_set_string(AVFormatContext *s, const char *key,
 529                             uint8_t *buf, int buf_size)
 530 {
 531     AVMetadataTag *tag;
 532     if ((tag = av_metadata_get(s->metadata, key, NULL, 0)))
 533         strncpy(buf, tag->value, buf_size);
 534     return !!tag;
 535 }
 536
 537 static int id3v1_create_tag(AVFormatContext *s, uint8_t *buf)
 538 {
 539     AVMetadataTag *tag;
 540     int i, count = 0;
 541
 542     memset(buf, 0, ID3v1_TAG_SIZE); /* fail safe */
 543     buf[0] = 'T';
 544     buf[1] = 'A';
 545     buf[2] = 'G';
 546     count += id3v1_set_string(s, "title",   buf +  3, 30);
 547     count += id3v1_set_string(s, "author",  buf + 33, 30);
 548     count += id3v1_set_string(s, "album",   buf + 63, 30);
 549     count += id3v1_set_string(s, "year",    buf + 93,  4);
 550     count += id3v1_set_string(s, "comment", buf + 97, 30);
 551     if ((tag = av_metadata_get(s->metadata, "track", NULL, 0))) {
 552         buf[125] = 0;
 553         buf[126] = atoi(tag->value);
 554         count++;
 555     }
 556     if ((tag = av_metadata_get(s->metadata, "genre", NULL, 0))) {
 557         for(i = 0; i <= ID3v1_GENRE_MAX; i++) {
 558             if (!strcasecmp(tag->value, id3v1_genre_str[i])) {
 559                 buf[127] = i;
 560                 count++;
 561                 break;
 562             }
 563         }
 564     }
 565     return count;
 566 }
 567
 568 /* simple formats */
 569
 570 static void id3v2_put_size(AVFormatContext *s, int size)
 571 {
 572     put_byte(s->pb, size >> 21 & 0x7f);
 573     put_byte(s->pb, size >> 14 & 0x7f);
 574     put_byte(s->pb, size >> 7  & 0x7f);
 575     put_byte(s->pb, size       & 0x7f);
 576 }
 577
 578 static void id3v2_put_ttag(AVFormatContext *s, const char *string, uint32_t tag)
 579 {
 580     int len = strlen(string);
 581     put_be32(s->pb, tag);
 582     id3v2_put_size(s, len + 1);
 583     put_be16(s->pb, 0);
 584     put_byte(s->pb, 3); /* UTF-8 */
 585     put_buffer(s->pb, string, len);
 586 }
 587
 588
 589 /**
 590  * Write an ID3v2.4 header at beginning of stream
 591  */
 592
 593 static int mp3_write_header(struct AVFormatContext *s)
 594 {
 595     AVMetadataTag *title, *author, *album, *genre, *copyright, *track, *year;
 596     int totlen = 0;
 597
 598     title     = av_metadata_get(s->metadata, "title",     NULL, 0);
 599     author    = av_metadata_get(s->metadata, "author",    NULL, 0);
 600     album     = av_metadata_get(s->metadata, "album",     NULL, 0);
 601     genre     = av_metadata_get(s->metadata, "genre",     NULL, 0);
 602     copyright = av_metadata_get(s->metadata, "copyright", NULL, 0);
 603     track     = av_metadata_get(s->metadata, "track",     NULL, 0);
 604     year      = av_metadata_get(s->metadata, "year",      NULL, 0);
 605
 606     if(title)     totlen += 11 + strlen(title->value);
 607     if(author)    totlen += 11 + strlen(author->value);
 608     if(album)     totlen += 11 + strlen(album->value);
 609     if(genre)     totlen += 11 + strlen(genre->value);
 610     if(copyright) totlen += 11 + strlen(copyright->value);
 611     if(track)     totlen += 11 + strlen(track->value);
 612     if(year)      totlen += 11 + strlen(year->value);
 613     if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT))
 614         totlen += strlen(LIBAVFORMAT_IDENT) + 11;
 615
 616     if(totlen == 0)
 617         return 0;
 618
 619     put_be32(s->pb, MKBETAG('I', 'D', '3', 0x04)); /* ID3v2.4 */
 620     put_byte(s->pb, 0);
 621     put_byte(s->pb, 0); /* flags */
 622
 623     id3v2_put_size(s, totlen);
 624
 625     if(title)     id3v2_put_ttag(s, title->value,     MKBETAG('T', 'I', 'T', '2'));
 626     if(author)    id3v2_put_ttag(s, author->value,    MKBETAG('T', 'P', 'E', '1'));
 627     if(album)     id3v2_put_ttag(s, album->value,     MKBETAG('T', 'A', 'L', 'B'));
 628     if(genre)     id3v2_put_ttag(s, genre->value,     MKBETAG('T', 'C', 'O', 'N'));
 629     if(copyright) id3v2_put_ttag(s, copyright->value, MKBETAG('T', 'C', 'O', 'P'));
 630     if(track)     id3v2_put_ttag(s, track->value,     MKBETAG('T', 'R', 'C', 'K'));
 631     if(year)      id3v2_put_ttag(s, year->value,      MKBETAG('T', 'Y', 'E', 'R'));
 632     if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT))
 633         id3v2_put_ttag(s, LIBAVFORMAT_IDENT,            MKBETAG('T', 'E', 'N', 'C'));
 634     return 0;
 635 }
 636
 637 static int mp3_write_packet(struct AVFormatContext *s, AVPacket *pkt)
 638 {
 639     put_buffer(s->pb, pkt->data, pkt->size);
 640     put_flush_packet(s->pb);
 641     return 0;
 642 }
 643
 644 static int mp3_write_trailer(struct AVFormatContext *s)
 645 {
 646     uint8_t buf[ID3v1_TAG_SIZE];
 647
 648     /* write the id3v1 tag */
 649     if (id3v1_create_tag(s, buf) > 0) {
 650         put_buffer(s->pb, buf, ID3v1_TAG_SIZE);
 651         put_flush_packet(s->pb);
 652     }
 653     return 0;
 654 }
 655 #endif /* CONFIG_MP2_MUXER || CONFIG_MP3_MUXER */
 656
 657 #if CONFIG_MP3_DEMUXER
 658 AVInputFormat mp3_demuxer = {
 659     "mp3",
 660     NULL_IF_CONFIG_SMALL("MPEG audio"),
 661     0,
 662     mp3_read_probe,
 663     mp3_read_header,
 664     mp3_read_packet,
 665     .flags= AVFMT_GENERIC_INDEX,
 666     .extensions = "mp2,mp3,m2a", /* XXX: use probe */
 667 };
 668 #endif
 669 #if CONFIG_MP2_MUXER
 670 AVOutputFormat mp2_muxer = {
 671     "mp2",
 672     NULL_IF_CONFIG_SMALL("MPEG audio layer 2"),
 673     "audio/x-mpeg",
 674     "mp2,m2a",
 675     0,
 676     CODEC_ID_MP2,
 677     CODEC_ID_NONE,
 678     NULL,
 679     mp3_write_packet,
 680     mp3_write_trailer,
 681 };
 682 #endif
 683 #if CONFIG_MP3_MUXER
 684 AVOutputFormat mp3_muxer = {
 685     "mp3",
 686     NULL_IF_CONFIG_SMALL("MPEG audio layer 3"),
 687     "audio/x-mpeg",
 688     "mp3",
 689     0,
 690     CODEC_ID_MP3,
 691     CODEC_ID_NONE,
 692     mp3_write_header,
 693     mp3_write_packet,
 694     mp3_write_trailer,
 695 };
 696 #endif