libavformat/id3v2.c

   1 /*
   2  * ID3v2 header parser
   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 "id3v2.h"
  23 #include "id3v1.h"
  24 #include "libavutil/avstring.h"
  25
  26 int ff_id3v2_match(const uint8_t *buf)
  27 {
  28     return  buf[0]         ==  'I' &&
  29             buf[1]         ==  'D' &&
  30             buf[2]         ==  '3' &&
  31             buf[3]         != 0xff &&
  32             buf[4]         != 0xff &&
  33            (buf[6] & 0x80) ==    0 &&
  34            (buf[7] & 0x80) ==    0 &&
  35            (buf[8] & 0x80) ==    0 &&
  36            (buf[9] & 0x80) ==    0;
  37 }
  38
  39 int ff_id3v2_tag_len(const uint8_t * buf)
  40 {
  41     int len = ((buf[6] & 0x7f) << 21) +
  42               ((buf[7] & 0x7f) << 14) +
  43               ((buf[8] & 0x7f) << 7) +
  44                (buf[9] & 0x7f) +
  45               ID3v2_HEADER_SIZE;
  46     if (buf[5] & 0x10)
  47         len += ID3v2_HEADER_SIZE;
  48     return len;
  49 }
  50
  51 void ff_id3v2_read(AVFormatContext *s)
  52 {
  53     int len, ret;
  54     uint8_t buf[ID3v2_HEADER_SIZE];
  55
  56     ret = get_buffer(s->pb, buf, ID3v2_HEADER_SIZE);
  57     if (ret != ID3v2_HEADER_SIZE)
  58         return;
  59     if (ff_id3v2_match(buf)) {
  60         /* parse ID3v2 header */
  61         len = ((buf[6] & 0x7f) << 21) |
  62             ((buf[7] & 0x7f) << 14) |
  63             ((buf[8] & 0x7f) << 7) |
  64             (buf[9] & 0x7f);
  65         ff_id3v2_parse(s, len, buf[3], buf[5]);
  66     } else {
  67         url_fseek(s->pb, 0, SEEK_SET);
  68     }
  69 }
  70
  71 static unsigned int get_size(ByteIOContext *s, int len)
  72 {
  73     int v = 0;
  74     while (len--)
  75         v = (v << 7) + (get_byte(s) & 0x7F);
  76     return v;
  77 }
  78
  79 static void read_ttag(AVFormatContext *s, int taglen, const char *key)
  80 {
  81     char *q, dst[512];
  82     int len, dstlen = sizeof(dst) - 1;
  83     unsigned genre;
  84
  85     dst[0] = 0;
  86     if (taglen < 1)
  87         return;
  88
  89     taglen--; /* account for encoding type byte */
  90
  91     switch (get_byte(s->pb)) { /* encoding type */
  92
  93     case 0:  /* ISO-8859-1 (0 - 255 maps directly into unicode) */
  94         q = dst;
  95         while (taglen--) {
  96             uint8_t tmp;
  97             PUT_UTF8(get_byte(s->pb), tmp, if (q - dst < dstlen - 1) *q++ = tmp;)
  98         }
  99         *q = '\0';
 100         break;
 101
 102     case 3:  /* UTF-8 */
 103         len = FFMIN(taglen, dstlen - 1);
 104         get_buffer(s->pb, dst, len);
 105         dst[len] = 0;
 106         break;
 107     }
 108
 109     if (!strcmp(key, "genre")
 110         && (sscanf(dst, "(%d)", &genre) == 1 || sscanf(dst, "%d", &genre) == 1)
 111         && genre <= ID3v1_GENRE_MAX)
 112         av_strlcpy(dst, ff_id3v1_genre_str[genre], sizeof(dst));
 113
 114     if (*dst)
 115         av_metadata_set(&s->metadata, key, dst);
 116 }
 117
 118 void ff_id3v2_parse(AVFormatContext *s, int len, uint8_t version, uint8_t flags)
 119 {
 120     int isv34, tlen;
 121     uint32_t tag;
 122     int64_t next;
 123     int taghdrlen;
 124     const char *reason;
 125
 126     switch (version) {
 127     case 2:
 128         if (flags & 0x40) {
 129             reason = "compression";
 130             goto error;
 131         }
 132         isv34 = 0;
 133         taghdrlen = 6;
 134         break;
 135
 136     case 3:
 137     case 4:
 138         isv34 = 1;
 139         taghdrlen = 10;
 140         break;
 141
 142     default:
 143         reason = "version";
 144         goto error;
 145     }
 146
 147     if (flags & 0x80) {
 148         reason = "unsynchronization";
 149         goto error;
 150     }
 151
 152     if (isv34 && flags & 0x40) /* Extended header present, just skip over it */
 153         url_fskip(s->pb, get_size(s->pb, 4));
 154
 155     while (len >= taghdrlen) {
 156         if (isv34) {
 157             tag  = get_be32(s->pb);
 158             if(version==3){
 159                 tlen = get_be32(s->pb);
 160             }else
 161                 tlen = get_size(s->pb, 4);
 162             get_be16(s->pb); /* flags */
 163         } else {
 164             tag  = get_be24(s->pb);
 165             tlen = get_be24(s->pb);
 166         }
 167         len -= taghdrlen + tlen;
 168
 169         if (len < 0)
 170             break;
 171
 172         next = url_ftell(s->pb) + tlen;
 173
 174         switch (tag) {
 175         case MKBETAG('T', 'I', 'T', '2'):
 176         case MKBETAG(0,   'T', 'T', '2'):
 177             read_ttag(s, tlen, "title");
 178             break;
 179         case MKBETAG('T', 'P', 'E', '1'):
 180         case MKBETAG(0,   'T', 'P', '1'):
 181             read_ttag(s, tlen, "author");
 182             break;
 183         case MKBETAG('T', 'A', 'L', 'B'):
 184         case MKBETAG(0,   'T', 'A', 'L'):
 185             read_ttag(s, tlen, "album");
 186             break;
 187         case MKBETAG('T', 'C', 'O', 'N'):
 188         case MKBETAG(0,   'T', 'C', 'O'):
 189             read_ttag(s, tlen, "genre");
 190             break;
 191         case MKBETAG('T', 'C', 'O', 'P'):
 192         case MKBETAG(0,   'T', 'C', 'R'):
 193             read_ttag(s, tlen, "copyright");
 194             break;
 195         case MKBETAG('T', 'R', 'C', 'K'):
 196         case MKBETAG(0,   'T', 'R', 'K'):
 197             read_ttag(s, tlen, "track");
 198             break;
 199         case 0:
 200             /* padding, skip to end */
 201             url_fskip(s->pb, len);
 202             len = 0;
 203             continue;
 204         }
 205         /* Skip to end of tag */
 206         url_fseek(s->pb, next, SEEK_SET);
 207     }
 208
 209     if (version == 4 && flags & 0x10) /* Footer preset, always 10 bytes, skip over it */
 210         url_fskip(s->pb, 10);
 211     return;
 212
 213   error:
 214     av_log(s, AV_LOG_INFO, "ID3v2.%d tag skipped, cannot handle %s\n", version, reason);
 215     url_fskip(s->pb, len);
 216 }