ffmpeg: libavformat/mp3.c Source File

00001 /*
00002  * MP3 muxer and demuxer
00003  * Copyright (c) 2003 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include <strings.h>
00023 #include "libavutil/avstring.h"
00024 #include "libavcodec/mpegaudio.h"
00025 #include "libavcodec/mpegaudiodecheader.h"
00026 #include "avformat.h"
00027 #include "id3v2.h"
00028 
00029 #define ID3v1_TAG_SIZE 128
00030 
00031 #define ID3v1_GENRE_MAX 125
00032 
00033 static const char * const id3v1_genre_str[ID3v1_GENRE_MAX + 1] = {
00034     [0] = "Blues",
00035     [1] = "Classic Rock",
00036     [2] = "Country",
00037     [3] = "Dance",
00038     [4] = "Disco",
00039     [5] = "Funk",
00040     [6] = "Grunge",
00041     [7] = "Hip-Hop",
00042     [8] = "Jazz",
00043     [9] = "Metal",
00044     [10] = "New Age",
00045     [11] = "Oldies",
00046     [12] = "Other",
00047     [13] = "Pop",
00048     [14] = "R&B",
00049     [15] = "Rap",
00050     [16] = "Reggae",
00051     [17] = "Rock",
00052     [18] = "Techno",
00053     [19] = "Industrial",
00054     [20] = "Alternative",
00055     [21] = "Ska",
00056     [22] = "Death Metal",
00057     [23] = "Pranks",
00058     [24] = "Soundtrack",
00059     [25] = "Euro-Techno",
00060     [26] = "Ambient",
00061     [27] = "Trip-Hop",
00062     [28] = "Vocal",
00063     [29] = "Jazz+Funk",
00064     [30] = "Fusion",
00065     [31] = "Trance",
00066     [32] = "Classical",
00067     [33] = "Instrumental",
00068     [34] = "Acid",
00069     [35] = "House",
00070     [36] = "Game",
00071     [37] = "Sound Clip",
00072     [38] = "Gospel",
00073     [39] = "Noise",
00074     [40] = "AlternRock",
00075     [41] = "Bass",
00076     [42] = "Soul",
00077     [43] = "Punk",
00078     [44] = "Space",
00079     [45] = "Meditative",
00080     [46] = "Instrumental Pop",
00081     [47] = "Instrumental Rock",
00082     [48] = "Ethnic",
00083     [49] = "Gothic",
00084     [50] = "Darkwave",
00085     [51] = "Techno-Industrial",
00086     [52] = "Electronic",
00087     [53] = "Pop-Folk",
00088     [54] = "Eurodance",
00089     [55] = "Dream",
00090     [56] = "Southern Rock",
00091     [57] = "Comedy",
00092     [58] = "Cult",
00093     [59] = "Gangsta",
00094     [60] = "Top 40",
00095     [61] = "Christian Rap",
00096     [62] = "Pop/Funk",
00097     [63] = "Jungle",
00098     [64] = "Native American",
00099     [65] = "Cabaret",
00100     [66] = "New Wave",
00101     [67] = "Psychadelic",
00102     [68] = "Rave",
00103     [69] = "Showtunes",
00104     [70] = "Trailer",
00105     [71] = "Lo-Fi",
00106     [72] = "Tribal",
00107     [73] = "Acid Punk",
00108     [74] = "Acid Jazz",
00109     [75] = "Polka",
00110     [76] = "Retro",
00111     [77] = "Musical",
00112     [78] = "Rock & Roll",
00113     [79] = "Hard Rock",
00114     [80] = "Folk",
00115     [81] = "Folk-Rock",
00116     [82] = "National Folk",
00117     [83] = "Swing",
00118     [84] = "Fast Fusion",
00119     [85] = "Bebob",
00120     [86] = "Latin",
00121     [87] = "Revival",
00122     [88] = "Celtic",
00123     [89] = "Bluegrass",
00124     [90] = "Avantgarde",
00125     [91] = "Gothic Rock",
00126     [92] = "Progressive Rock",
00127     [93] = "Psychedelic Rock",
00128     [94] = "Symphonic Rock",
00129     [95] = "Slow Rock",
00130     [96] = "Big Band",
00131     [97] = "Chorus",
00132     [98] = "Easy Listening",
00133     [99] = "Acoustic",
00134     [100] = "Humour",
00135     [101] = "Speech",
00136     [102] = "Chanson",
00137     [103] = "Opera",
00138     [104] = "Chamber Music",
00139     [105] = "Sonata",
00140     [106] = "Symphony",
00141     [107] = "Booty Bass",
00142     [108] = "Primus",
00143     [109] = "Porn Groove",
00144     [110] = "Satire",
00145     [111] = "Slow Jam",
00146     [112] = "Club",
00147     [113] = "Tango",
00148     [114] = "Samba",
00149     [115] = "Folklore",
00150     [116] = "Ballad",
00151     [117] = "Power Ballad",
00152     [118] = "Rhythmic Soul",
00153     [119] = "Freestyle",
00154     [120] = "Duet",
00155     [121] = "Punk Rock",
00156     [122] = "Drum Solo",
00157     [123] = "A capella",
00158     [124] = "Euro-House",
00159     [125] = "Dance Hall",
00160 };
00161 
00162 static unsigned int id3v2_get_size(ByteIOContext *s, int len)
00163 {
00164     int v=0;
00165     while(len--)
00166         v= (v<<7) + (get_byte(s)&0x7F);
00167     return v;
00168 }
00169 
00170 static void id3v2_read_ttag(AVFormatContext *s, int taglen, const char *key)
00171 {
00172     char *q, dst[512];
00173     int len, dstlen = sizeof(dst) - 1;
00174     unsigned genre;
00175 
00176     dst[0]= 0;
00177     if(taglen < 1)
00178         return;
00179 
00180     taglen--; /* account for encoding type byte */
00181 
00182     switch(get_byte(s->pb)) { /* encoding type */
00183 
00184     case 0:  /* ISO-8859-1 (0 - 255 maps directly into unicode) */
00185         q = dst;
00186         while(taglen--) {
00187             uint8_t tmp;
00188             PUT_UTF8(get_byte(s->pb), tmp, if (q - dst < dstlen - 1) *q++ = tmp;)
00189         }
00190         *q = '\0';
00191         break;
00192 
00193     case 3:  /* UTF-8 */
00194         len = FFMIN(taglen, dstlen-1);
00195         get_buffer(s->pb, dst, len);
00196         dst[len] = 0;
00197         break;
00198     }
00199 
00200     if (!strcmp(key, "genre")
00201         && sscanf(dst, "(%d)", &genre) == 1 && genre <= ID3v1_GENRE_MAX)
00202         av_strlcpy(dst, id3v1_genre_str[genre], sizeof(dst));
00203 
00204     if (*dst)
00205         av_metadata_set(&s->metadata, key, dst);
00206 }
00207 
00215 static void id3v2_parse(AVFormatContext *s, int len, uint8_t version, uint8_t flags)
00216 {
00217     int isv34, tlen;
00218     uint32_t tag;
00219     int64_t next;
00220     int taghdrlen;
00221     const char *reason;
00222 
00223     switch(version) {
00224     case 2:
00225         if(flags & 0x40) {
00226             reason = "compression";
00227             goto error;
00228         }
00229         isv34 = 0;
00230         taghdrlen = 6;
00231         break;
00232 
00233     case 3:
00234     case 4:
00235         isv34 = 1;
00236         taghdrlen = 10;
00237         break;
00238 
00239     default:
00240         reason = "version";
00241         goto error;
00242     }
00243 
00244     if(flags & 0x80) {
00245         reason = "unsynchronization";
00246         goto error;
00247     }
00248 
00249     if(isv34 && flags & 0x40) /* Extended header present, just skip over it */
00250         url_fskip(s->pb, id3v2_get_size(s->pb, 4));
00251 
00252     while(len >= taghdrlen) {
00253         if(isv34) {
00254             tag  = get_be32(s->pb);
00255             tlen = id3v2_get_size(s->pb, 4);
00256             get_be16(s->pb); /* flags */
00257         } else {
00258             tag  = get_be24(s->pb);
00259             tlen = id3v2_get_size(s->pb, 3);
00260         }
00261         len -= taghdrlen + tlen;
00262 
00263         if(len < 0)
00264             break;
00265 
00266         next = url_ftell(s->pb) + tlen;
00267 
00268         switch(tag) {
00269         case MKBETAG('T', 'I', 'T', '2'):
00270         case MKBETAG(0,   'T', 'T', '2'):
00271             id3v2_read_ttag(s, tlen, "title");
00272             break;
00273         case MKBETAG('T', 'P', 'E', '1'):
00274         case MKBETAG(0,   'T', 'P', '1'):
00275             id3v2_read_ttag(s, tlen, "author");
00276             break;
00277         case MKBETAG('T', 'A', 'L', 'B'):
00278         case MKBETAG(0,   'T', 'A', 'L'):
00279             id3v2_read_ttag(s, tlen, "album");
00280             break;
00281         case MKBETAG('T', 'C', 'O', 'N'):
00282         case MKBETAG(0,   'T', 'C', 'O'):
00283             id3v2_read_ttag(s, tlen, "genre");
00284             break;
00285         case MKBETAG('T', 'C', 'O', 'P'):
00286         case MKBETAG(0,   'T', 'C', 'R'):
00287             id3v2_read_ttag(s, tlen, "copyright");
00288             break;
00289         case MKBETAG('T', 'R', 'C', 'K'):
00290         case MKBETAG(0,   'T', 'R', 'K'):
00291             id3v2_read_ttag(s, tlen, "track");
00292             break;
00293         case 0:
00294             /* padding, skip to end */
00295             url_fskip(s->pb, len);
00296             len = 0;
00297             continue;
00298         }
00299         /* Skip to end of tag */
00300         url_fseek(s->pb, next, SEEK_SET);
00301     }
00302 
00303     if(version == 4 && flags & 0x10) /* Footer preset, always 10 bytes, skip over it */
00304         url_fskip(s->pb, 10);
00305     return;
00306 
00307   error:
00308     av_log(s, AV_LOG_INFO, "ID3v2.%d tag skipped, cannot handle %s\n", version, reason);
00309     url_fskip(s->pb, len);
00310 }
00311 
00312 static void id3v1_get_string(AVFormatContext *s, const char *key,
00313                              const uint8_t *buf, int buf_size)
00314 {
00315     int i, c;
00316     char *q, str[512];
00317 
00318     q = str;
00319     for(i = 0; i < buf_size; i++) {
00320         c = buf[i];
00321         if (c == '\0')
00322             break;
00323         if ((q - str) >= sizeof(str) - 1)
00324             break;
00325         *q++ = c;
00326     }
00327     *q = '\0';
00328 
00329     if (*str)
00330         av_metadata_set(&s->metadata, key, str);
00331 }
00332 
00333 /* 'buf' must be ID3v1_TAG_SIZE byte long */
00334 static int id3v1_parse_tag(AVFormatContext *s, const uint8_t *buf)
00335 {
00336     char str[5];
00337     int genre;
00338 
00339     if (!(buf[0] == 'T' &&
00340           buf[1] == 'A' &&
00341           buf[2] == 'G'))
00342         return -1;
00343     id3v1_get_string(s, "title",   buf +  3, 30);
00344     id3v1_get_string(s, "author",  buf + 33, 30);
00345     id3v1_get_string(s, "album",   buf + 63, 30);
00346     id3v1_get_string(s, "year",    buf + 93,  4);
00347     id3v1_get_string(s, "comment", buf + 97, 30);
00348     if (buf[125] == 0 && buf[126] != 0) {
00349         snprintf(str, sizeof(str), "%d", buf[126]);
00350         av_metadata_set(&s->metadata, "track", str);
00351     }
00352     genre = buf[127];
00353     if (genre <= ID3v1_GENRE_MAX)
00354         av_metadata_set(&s->metadata, "genre", id3v1_genre_str[genre]);
00355     return 0;
00356 }
00357 
00358 /* mp3 read */
00359 
00360 static int mp3_read_probe(AVProbeData *p)
00361 {
00362     int max_frames, first_frames = 0;
00363     int fsize, frames, sample_rate;
00364     uint32_t header;
00365     uint8_t *buf, *buf0, *buf2, *end;
00366     AVCodecContext avctx;
00367 
00368     buf0 = p->buf;
00369     if(ff_id3v2_match(buf0)) {
00370         buf0 += ff_id3v2_tag_len(buf0);
00371     }
00372 
00373     max_frames = 0;
00374     buf = buf0;
00375     end = p->buf + p->buf_size - sizeof(uint32_t);
00376 
00377     for(; buf < end; buf= buf2+1) {
00378         buf2 = buf;
00379 
00380         for(frames = 0; buf2 < end; frames++) {
00381             header = AV_RB32(buf2);
00382             fsize = ff_mpa_decode_header(&avctx, header, &sample_rate, &sample_rate, &sample_rate, &sample_rate);
00383             if(fsize < 0)
00384                 break;
00385             buf2 += fsize;
00386         }
00387         max_frames = FFMAX(max_frames, frames);
00388         if(buf == buf0)
00389             first_frames= frames;
00390     }
00391     if   (first_frames>=3) return AVPROBE_SCORE_MAX/2+1;
00392     else if(max_frames>500)return AVPROBE_SCORE_MAX/2;
00393     else if(max_frames>=3) return AVPROBE_SCORE_MAX/4;
00394     else if(buf0!=p->buf)  return AVPROBE_SCORE_MAX/4-1;
00395     else if(max_frames>=1) return 1;
00396     else                   return 0;
00397 }
00398 
00402 static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
00403 {
00404     uint32_t v, spf;
00405     int frames = -1; /* Total number of frames in file */
00406     const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}};
00407     MPADecodeHeader c;
00408     int vbrtag_size = 0;
00409 
00410     v = get_be32(s->pb);
00411     if(ff_mpa_check_header(v) < 0)
00412       return -1;
00413 
00414     if (ff_mpegaudio_decode_header(&c, v) == 0)
00415         vbrtag_size = c.frame_size;
00416     if(c.layer != 3)
00417         return -1;
00418 
00419     /* Check for Xing / Info tag */
00420     url_fseek(s->pb, xing_offtbl[c.lsf == 1][c.nb_channels == 1], SEEK_CUR);
00421     v = get_be32(s->pb);
00422     if(v == MKBETAG('X', 'i', 'n', 'g') || v == MKBETAG('I', 'n', 'f', 'o')) {
00423         v = get_be32(s->pb);
00424         if(v & 0x1)
00425             frames = get_be32(s->pb);
00426     }
00427 
00428     /* Check for VBRI tag (always 32 bytes after end of mpegaudio header) */
00429     url_fseek(s->pb, base + 4 + 32, SEEK_SET);
00430     v = get_be32(s->pb);
00431     if(v == MKBETAG('V', 'B', 'R', 'I')) {
00432         /* Check tag version */
00433         if(get_be16(s->pb) == 1) {
00434             /* skip delay, quality and total bytes */
00435             url_fseek(s->pb, 8, SEEK_CUR);
00436             frames = get_be32(s->pb);
00437         }
00438     }
00439 
00440     if(frames < 0)
00441         return -1;
00442 
00443     /* Skip the vbr tag frame */
00444     url_fseek(s->pb, base + vbrtag_size, SEEK_SET);
00445 
00446     spf = c.lsf ? 576 : 1152; /* Samples per frame, layer 3 */
00447     st->duration = av_rescale_q(frames, (AVRational){spf, c.sample_rate},
00448                                 st->time_base);
00449     return 0;
00450 }
00451 
00452 static int mp3_read_header(AVFormatContext *s,
00453                            AVFormatParameters *ap)
00454 {
00455     AVStream *st;
00456     uint8_t buf[ID3v1_TAG_SIZE];
00457     int len, ret, filesize;
00458     int64_t off;
00459 
00460     st = av_new_stream(s, 0);
00461     if (!st)
00462         return AVERROR(ENOMEM);
00463 
00464     st->codec->codec_type = CODEC_TYPE_AUDIO;
00465     st->codec->codec_id = CODEC_ID_MP3;
00466     st->need_parsing = AVSTREAM_PARSE_FULL;
00467     st->start_time = 0;
00468 
00469     /* try to get the TAG */
00470     if (!url_is_streamed(s->pb)) {
00471         /* XXX: change that */
00472         filesize = url_fsize(s->pb);
00473         if (filesize > 128) {
00474             url_fseek(s->pb, filesize - 128, SEEK_SET);
00475             ret = get_buffer(s->pb, buf, ID3v1_TAG_SIZE);
00476             if (ret == ID3v1_TAG_SIZE) {
00477                 id3v1_parse_tag(s, buf);
00478             }
00479             url_fseek(s->pb, 0, SEEK_SET);
00480         }
00481     }
00482 
00483     /* if ID3v2 header found, skip it */
00484     ret = get_buffer(s->pb, buf, ID3v2_HEADER_SIZE);
00485     if (ret != ID3v2_HEADER_SIZE)
00486         return -1;
00487     if (ff_id3v2_match(buf)) {
00488         /* parse ID3v2 header */
00489         len = ((buf[6] & 0x7f) << 21) |
00490             ((buf[7] & 0x7f) << 14) |
00491             ((buf[8] & 0x7f) << 7) |
00492             (buf[9] & 0x7f);
00493         id3v2_parse(s, len, buf[3], buf[5]);
00494     } else {
00495         url_fseek(s->pb, 0, SEEK_SET);
00496     }
00497 
00498     off = url_ftell(s->pb);
00499     if (mp3_parse_vbr_tags(s, st, off) < 0)
00500         url_fseek(s->pb, off, SEEK_SET);
00501 
00502     /* the parameters will be extracted from the compressed bitstream */
00503     return 0;
00504 }
00505 
00506 #define MP3_PACKET_SIZE 1024
00507 
00508 static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt)
00509 {
00510     int ret, size;
00511     //    AVStream *st = s->streams[0];
00512 
00513     size= MP3_PACKET_SIZE;
00514 
00515     ret= av_get_packet(s->pb, pkt, size);
00516 
00517     pkt->stream_index = 0;
00518     if (ret <= 0) {
00519         return AVERROR(EIO);
00520     }
00521     /* note: we need to modify the packet size here to handle the last
00522        packet */
00523     pkt->size = ret;
00524     return ret;
00525 }
00526 
00527 #if CONFIG_MP2_MUXER || CONFIG_MP3_MUXER
00528 static int id3v1_set_string(AVFormatContext *s, const char *key,
00529                             uint8_t *buf, int buf_size)
00530 {
00531     AVMetadataTag *tag;
00532     if ((tag = av_metadata_get(s->metadata, key, NULL, 0)))
00533         strncpy(buf, tag->value, buf_size);
00534     return !!tag;
00535 }
00536 
00537 static int id3v1_create_tag(AVFormatContext *s, uint8_t *buf)
00538 {
00539     AVMetadataTag *tag;
00540     int i, count = 0;
00541 
00542     memset(buf, 0, ID3v1_TAG_SIZE); /* fail safe */
00543     buf[0] = 'T';
00544     buf[1] = 'A';
00545     buf[2] = 'G';
00546     count += id3v1_set_string(s, "title",   buf +  3, 30);
00547     count += id3v1_set_string(s, "author",  buf + 33, 30);
00548     count += id3v1_set_string(s, "album",   buf + 63, 30);
00549     count += id3v1_set_string(s, "year",    buf + 93,  4);
00550     count += id3v1_set_string(s, "comment", buf + 97, 30);
00551     if ((tag = av_metadata_get(s->metadata, "track", NULL, 0))) {
00552         buf[125] = 0;
00553         buf[126] = atoi(tag->value);
00554         count++;
00555     }
00556     if ((tag = av_metadata_get(s->metadata, "genre", NULL, 0))) {
00557         for(i = 0; i <= ID3v1_GENRE_MAX; i++) {
00558             if (!strcasecmp(tag->value, id3v1_genre_str[i])) {
00559                 buf[127] = i;
00560                 count++;
00561                 break;
00562             }
00563         }
00564     }
00565     return count;
00566 }
00567 
00568 /* simple formats */
00569 
00570 static void id3v2_put_size(AVFormatContext *s, int size)
00571 {
00572     put_byte(s->pb, size >> 21 & 0x7f);
00573     put_byte(s->pb, size >> 14 & 0x7f);
00574     put_byte(s->pb, size >> 7  & 0x7f);
00575     put_byte(s->pb, size       & 0x7f);
00576 }
00577 
00578 static void id3v2_put_ttag(AVFormatContext *s, const char *string, uint32_t tag)
00579 {
00580     int len = strlen(string);
00581     put_be32(s->pb, tag);
00582     id3v2_put_size(s, len + 1);
00583     put_be16(s->pb, 0);
00584     put_byte(s->pb, 3); /* UTF-8 */
00585     put_buffer(s->pb, string, len);
00586 }
00587 
00588 
00593 static int mp3_write_header(struct AVFormatContext *s)
00594 {
00595     AVMetadataTag *title, *author, *album, *genre, *copyright, *track, *year;
00596     int totlen = 0;
00597 
00598     title     = av_metadata_get(s->metadata, "title",     NULL, 0);
00599     author    = av_metadata_get(s->metadata, "author",    NULL, 0);
00600     album     = av_metadata_get(s->metadata, "album",     NULL, 0);
00601     genre     = av_metadata_get(s->metadata, "genre",     NULL, 0);
00602     copyright = av_metadata_get(s->metadata, "copyright", NULL, 0);
00603     track     = av_metadata_get(s->metadata, "track",     NULL, 0);
00604     year      = av_metadata_get(s->metadata, "year",      NULL, 0);
00605 
00606     if(title)     totlen += 11 + strlen(title->value);
00607     if(author)    totlen += 11 + strlen(author->value);
00608     if(album)     totlen += 11 + strlen(album->value);
00609     if(genre)     totlen += 11 + strlen(genre->value);
00610     if(copyright) totlen += 11 + strlen(copyright->value);
00611     if(track)     totlen += 11 + strlen(track->value);
00612     if(year)      totlen += 11 + strlen(year->value);
00613     if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT))
00614         totlen += strlen(LIBAVFORMAT_IDENT) + 11;
00615 
00616     if(totlen == 0)
00617         return 0;
00618 
00619     put_be32(s->pb, MKBETAG('I', 'D', '3', 0x04)); /* ID3v2.4 */
00620     put_byte(s->pb, 0);
00621     put_byte(s->pb, 0); /* flags */
00622 
00623     id3v2_put_size(s, totlen);
00624 
00625     if(title)     id3v2_put_ttag(s, title->value,     MKBETAG('T', 'I', 'T', '2'));
00626     if(author)    id3v2_put_ttag(s, author->value,    MKBETAG('T', 'P', 'E', '1'));
00627     if(album)     id3v2_put_ttag(s, album->value,     MKBETAG('T', 'A', 'L', 'B'));
00628     if(genre)     id3v2_put_ttag(s, genre->value,     MKBETAG('T', 'C', 'O', 'N'));
00629     if(copyright) id3v2_put_ttag(s, copyright->value, MKBETAG('T', 'C', 'O', 'P'));
00630     if(track)     id3v2_put_ttag(s, track->value,     MKBETAG('T', 'R', 'C', 'K'));
00631     if(year)      id3v2_put_ttag(s, year->value,      MKBETAG('T', 'Y', 'E', 'R'));
00632     if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT))
00633         id3v2_put_ttag(s, LIBAVFORMAT_IDENT,            MKBETAG('T', 'E', 'N', 'C'));
00634     return 0;
00635 }
00636 
00637 static int mp3_write_packet(struct AVFormatContext *s, AVPacket *pkt)
00638 {
00639     put_buffer(s->pb, pkt->data, pkt->size);
00640     put_flush_packet(s->pb);
00641     return 0;
00642 }
00643 
00644 static int mp3_write_trailer(struct AVFormatContext *s)
00645 {
00646     uint8_t buf[ID3v1_TAG_SIZE];
00647 
00648     /* write the id3v1 tag */
00649     if (id3v1_create_tag(s, buf) > 0) {
00650         put_buffer(s->pb, buf, ID3v1_TAG_SIZE);
00651         put_flush_packet(s->pb);
00652     }
00653     return 0;
00654 }
00655 #endif /* CONFIG_MP2_MUXER || CONFIG_MP3_MUXER */
00656 
00657 #if CONFIG_MP3_DEMUXER
00658 AVInputFormat mp3_demuxer = {
00659     "mp3",
00660     NULL_IF_CONFIG_SMALL("MPEG audio layer 2/3"),
00661     0,
00662     mp3_read_probe,
00663     mp3_read_header,
00664     mp3_read_packet,
00665     .flags= AVFMT_GENERIC_INDEX,
00666     .extensions = "mp2,mp3,m2a", /* XXX: use probe */
00667 };
00668 #endif
00669 #if CONFIG_MP2_MUXER
00670 AVOutputFormat mp2_muxer = {
00671     "mp2",
00672     NULL_IF_CONFIG_SMALL("MPEG audio layer 2"),
00673     "audio/x-mpeg",
00674     "mp2,m2a",
00675     0,
00676     CODEC_ID_MP2,
00677     CODEC_ID_NONE,
00678     NULL,
00679     mp3_write_packet,
00680     mp3_write_trailer,
00681 };
00682 #endif
00683 #if CONFIG_MP3_MUXER
00684 AVOutputFormat mp3_muxer = {
00685     "mp3",
00686     NULL_IF_CONFIG_SMALL("MPEG audio layer 3"),
00687     "audio/x-mpeg",
00688     "mp3",
00689     0,
00690     CODEC_ID_MP3,
00691     CODEC_ID_NONE,
00692     mp3_write_header,
00693     mp3_write_packet,
00694     mp3_write_trailer,
00695 };
00696 #endif