apps/metadata/ape.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2005 Dave Chapman
  11  *
  12  * All files in this archive are subject to the GNU General Public License.
  13  * See the file COPYING in the source tree root for full license agreement.
  14  *
  15  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16  * KIND, either express or implied.
  17  *
  18  ****************************************************************************/
  19 #include <stdio.h>
  20 #include <string.h>
  21 #include <stdlib.h>
  22 #include <ctype.h>
  23 #include <inttypes.h>
  24
  25 #include "system.h"
  26 #include "id3.h"
  27 #include "metadata_common.h"
  28 #include "metadata_parsers.h"
  29 #include "structec.h"
  30
  31 #define APETAG_HEADER_LENGTH        32
  32 #define APETAG_HEADER_FORMAT        "8llll8"
  33 #define APETAG_ITEM_HEADER_FORMAT   "ll"
  34 #define APETAG_ITEM_TYPE_MASK       3
  35
  36 struct apetag_header
  37 {
  38     char id[8];
  39     long version;
  40     long length;
  41     long item_count;
  42     long flags;
  43     char reserved[8];
  44 };
  45
  46 struct apetag_item_header
  47 {
  48     long length;
  49     long flags;
  50 };
  51
  52 /* Read the items in an APEV2 tag. Only looks for a tag at the end of a
  53  * file. Returns true if a tag was found and fully read, false otherwise.
  54  */
  55 bool read_ape_tags(int fd, struct mp3entry* id3)
  56 {
  57     struct apetag_header header;
  58
  59     if ((lseek(fd, -APETAG_HEADER_LENGTH, SEEK_END) < 0)
  60         || (ecread(fd, &header, 1, APETAG_HEADER_FORMAT, IS_BIG_ENDIAN) != APETAG_HEADER_LENGTH)
  61         || (memcmp(header.id, "APETAGEX", sizeof(header.id))))
  62     {
  63         return false;
  64     }
  65
  66     if ((header.version == 2000) && (header.item_count > 0)
  67         && (header.length > APETAG_HEADER_LENGTH))
  68     {
  69         char *buf = id3->id3v2buf;
  70         unsigned int buf_remaining = sizeof(id3->id3v2buf)
  71             + sizeof(id3->id3v1buf);
  72         unsigned int tag_remaining = header.length - APETAG_HEADER_LENGTH;
  73         int i;
  74
  75         if (lseek(fd, -header.length, SEEK_END) < 0)
  76         {
  77             return false;
  78         }
  79
  80         for (i = 0; i < header.item_count; i++)
  81         {
  82             struct apetag_item_header item;
  83             char name[TAG_NAME_LENGTH];
  84             char value[TAG_VALUE_LENGTH];
  85             long r;
  86
  87             if (tag_remaining < sizeof(item))
  88             {
  89                 break;
  90             }
  91
  92             if (ecread(fd, &item, 1, APETAG_ITEM_HEADER_FORMAT, IS_BIG_ENDIAN) < (long) sizeof(item))
  93             {
  94                 return false;
  95             }
  96
  97             tag_remaining -= sizeof(item);
  98             r = read_string(fd, name, sizeof(name), 0, tag_remaining);
  99
 100             if (r == -1)
 101             {
 102                 return false;
 103             }
 104
 105             tag_remaining -= r + item.length;
 106
 107             if ((item.flags & APETAG_ITEM_TYPE_MASK) == 0)
 108             {
 109                 long len;
 110
 111                 if (read_string(fd, value, sizeof(value), -1, item.length)
 112                     != item.length)
 113                 {
 114                     return false;
 115                 }
 116
 117                 len = parse_tag(name, value, id3, buf, buf_remaining,
 118                     TAGTYPE_APE);
 119                 buf += len;
 120                 buf_remaining -= len;
 121             }
 122             else
 123             {
 124                 if (lseek(fd, item.length, SEEK_CUR) < 0)
 125                 {
 126                     return false;
 127                 }
 128             }
 129         }
 130     }
 131
 132     return true;
 133 }