libavformat/apetag.c

   1 /*
   2  * APE tag handling
   3  * Copyright (c) 2007 Benjamin Zores <ben@geexbox.org>
   4  *  based upon libdemac from Dave Chapman.
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "libavutil/intreadwrite.h"
  24 #include "avformat.h"
  25
  26 #define ENABLE_DEBUG 0
  27
  28 #define APE_TAG_VERSION               2000
  29 #define APE_TAG_FOOTER_BYTES          32
  30 #define APE_TAG_FLAG_CONTAINS_HEADER  (1 << 31)
  31 #define APE_TAG_FLAG_IS_HEADER        (1 << 29)
  32
  33 static int ape_tag_read_field(AVFormatContext *s)
  34 {
  35     ByteIOContext *pb = s->pb;
  36     uint8_t key[1024], value[1024];
  37     uint32_t size, flags;
  38     int i, l, c;
  39
  40     size = get_le32(pb);  /* field size */
  41     flags = get_le32(pb); /* field flags */
  42     for (i = 0; i < sizeof(key) - 1; i++) {
  43         c = get_byte(pb);
  44         if (c < 0x20 || c > 0x7E)
  45             break;
  46         else
  47             key[i] = c;
  48     }
  49     key[i] = 0;
  50     if (c != 0) {
  51         av_log(s, AV_LOG_WARNING, "Invalid APE tag key '%s'.\n", key);
  52         return -1;
  53     }
  54     l = FFMIN(size, sizeof(value)-1);
  55     get_buffer(pb, value, l);
  56     value[l] = 0;
  57     url_fskip(pb, size-l);
  58     if (l < size)
  59         av_log(s, AV_LOG_WARNING, "Too long '%s' tag was truncated.\n", key);
  60     av_metadata_set(&s->metadata, key, value);
  61     return 0;
  62 }
  63
  64 void ff_ape_parse_tag(AVFormatContext *s)
  65 {
  66     ByteIOContext *pb = s->pb;
  67     int file_size = url_fsize(pb);
  68     uint32_t val, fields, tag_bytes;
  69     uint8_t buf[8];
  70     int i;
  71
  72     if (file_size < APE_TAG_FOOTER_BYTES)
  73         return;
  74
  75     url_fseek(pb, file_size - APE_TAG_FOOTER_BYTES, SEEK_SET);
  76
  77     get_buffer(pb, buf, 8);    /* APETAGEX */
  78     if (strncmp(buf, "APETAGEX", 8)) {
  79         return;
  80     }
  81
  82     val = get_le32(pb);        /* APE tag version */
  83     if (val > APE_TAG_VERSION) {
  84         av_log(s, AV_LOG_ERROR, "Unsupported tag version. (>=%d)\n", APE_TAG_VERSION);
  85         return;
  86     }
  87
  88     tag_bytes = get_le32(pb);  /* tag size */
  89     if (tag_bytes - APE_TAG_FOOTER_BYTES > (1024 * 1024 * 16)) {
  90         av_log(s, AV_LOG_ERROR, "Tag size is way too big\n");
  91         return;
  92     }
  93
  94     fields = get_le32(pb);     /* number of fields */
  95     if (fields > 65536) {
  96         av_log(s, AV_LOG_ERROR, "Too many tag fields (%d)\n", fields);
  97         return;
  98     }
  99
 100     val = get_le32(pb);        /* flags */
 101     if (val & APE_TAG_FLAG_IS_HEADER) {
 102         av_log(s, AV_LOG_ERROR, "APE Tag is a header\n");
 103         return;
 104     }
 105
 106     url_fseek(pb, file_size - tag_bytes, SEEK_SET);
 107
 108     for (i=0; i<fields; i++)
 109         if (ape_tag_read_field(s) < 0) break;
 110
 111 #if ENABLE_DEBUG
 112     av_log(s, AV_LOG_DEBUG, "\nAPE Tags:\n\n");
 113     av_log(s, AV_LOG_DEBUG, "title     = %s\n", s->title);
 114     av_log(s, AV_LOG_DEBUG, "author    = %s\n", s->author);
 115     av_log(s, AV_LOG_DEBUG, "copyright = %s\n", s->copyright);
 116     av_log(s, AV_LOG_DEBUG, "comment   = %s\n", s->comment);
 117     av_log(s, AV_LOG_DEBUG, "album     = %s\n", s->album);
 118     av_log(s, AV_LOG_DEBUG, "year      = %d\n", s->year);
 119     av_log(s, AV_LOG_DEBUG, "track     = %d\n", s->track);
 120     av_log(s, AV_LOG_DEBUG, "genre     = %s\n", s->genre);
 121 #endif
 122 }