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  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <stdlib.h>
  24 #include <ctype.h>
  25 #include <inttypes.h>
  26
  27 #include "system.h"
  28 #include "metadata.h"
  29 #include "metadata_common.h"
  30 #include "metadata_parsers.h"
  31 #include "structec.h"
  32
  33 #define APETAG_HEADER_LENGTH        32
  34 #define APETAG_HEADER_FORMAT        "8llll8"
  35 #define APETAG_ITEM_HEADER_FORMAT   "ll"
  36 #define APETAG_ITEM_TYPE_MASK       3
  37
  38 struct apetag_header
  39 {
  40     char id[8];
  41     long version;
  42     long length;
  43     long item_count;
  44     long flags;
  45     char reserved[8];
  46 };
  47
  48 struct apetag_item_header
  49 {
  50     long length;
  51     long flags;
  52 };
  53
  54 /* Read the items in an APEV2 tag. Only looks for a tag at the end of a
  55  * file. Returns true if a tag was found and fully read, false otherwise.
  56  */
  57 bool read_ape_tags(int fd, struct mp3entry* id3)
  58 {
  59     struct apetag_header header;
  60
  61     if ((lseek(fd, -APETAG_HEADER_LENGTH, SEEK_END) < 0)
  62         || (ecread(fd, &header, 1, APETAG_HEADER_FORMAT, IS_BIG_ENDIAN) != APETAG_HEADER_LENGTH)
  63         || (memcmp(header.id, "APETAGEX", sizeof(header.id))))
  64     {
  65         return false;
  66     }
  67
  68     if ((header.version == 2000) && (header.item_count > 0)
  69         && (header.length > APETAG_HEADER_LENGTH))
  70     {
  71         char *buf = id3->id3v2buf;
  72         unsigned int buf_remaining = sizeof(id3->id3v2buf)
  73             + sizeof(id3->id3v1buf);
  74         unsigned int tag_remaining = header.length - APETAG_HEADER_LENGTH;
  75         int i;
  76
  77         if (lseek(fd, -header.length, SEEK_END) < 0)
  78         {
  79             return false;
  80         }
  81
  82         for (i = 0; i < header.item_count; i++)
  83         {
  84             struct apetag_item_header item;
  85             char name[TAG_NAME_LENGTH];
  86             char value[TAG_VALUE_LENGTH];
  87             long r;
  88
  89             if (tag_remaining < sizeof(item))
  90             {
  91                 break;
  92             }
  93
  94             if (ecread(fd, &item, 1, APETAG_ITEM_HEADER_FORMAT, IS_BIG_ENDIAN) < (long) sizeof(item))
  95             {
  96                 return false;
  97             }
  98
  99             tag_remaining -= sizeof(item);
 100             r = read_string(fd, name, sizeof(name), 0, tag_remaining);
 101
 102             if (r == -1)
 103             {
 104                 return false;
 105             }
 106
 107             tag_remaining -= r + item.length;
 108
 109             if ((item.flags & APETAG_ITEM_TYPE_MASK) == 0)
 110             {
 111                 long len;
 112
 113                 if (read_string(fd, value, sizeof(value), -1, item.length)
 114                     != item.length)
 115                 {
 116                     return false;
 117                 }
 118
 119                 len = parse_tag(name, value, id3, buf, buf_remaining,
 120                     TAGTYPE_APE);
 121                 buf += len;
 122                 buf_remaining -= len;
 123             }
 124             else
 125             {
 126                 if (lseek(fd, item.length, SEEK_CUR) < 0)
 127                 {
 128                     return false;
 129                 }
 130             }
 131         }
 132     }
 133
 134     return true;
 135 }