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 "structec.h"
  29
  30 #define APETAG_HEADER_LENGTH        32
  31 #define APETAG_HEADER_FORMAT        "8llll8"
  32 #define APETAG_ITEM_HEADER_FORMAT   "ll"
  33 #define APETAG_ITEM_TYPE_MASK       3
  34
  35 struct apetag_header
  36 {
  37     char id[8];
  38     long version;
  39     long length;
  40     long item_count;
  41     long flags;
  42     char reserved[8];
  43 };
  44
  45 struct apetag_item_header
  46 {
  47     long length;
  48     long flags;
  49 };
  50
  51 /* Read the items in an APEV2 tag. Only looks for a tag at the end of a
  52  * file. Returns true if a tag was found and fully read, false otherwise.
  53  */
  54 bool read_ape_tags(int fd, struct mp3entry* id3)
  55 {
  56     struct apetag_header header;
  57
  58     if ((lseek(fd, -APETAG_HEADER_LENGTH, SEEK_END) < 0)
  59         || (ecread(fd, &header, 1, APETAG_HEADER_FORMAT, IS_BIG_ENDIAN) != APETAG_HEADER_LENGTH)
  60         || (memcmp(header.id, "APETAGEX", sizeof(header.id))))
  61     {
  62         return false;
  63     }
  64
  65     if ((header.version == 2000) && (header.item_count > 0)
  66         && (header.length > APETAG_HEADER_LENGTH))
  67     {
  68         char *buf = id3->id3v2buf;
  69         unsigned int buf_remaining = sizeof(id3->id3v2buf)
  70             + sizeof(id3->id3v1buf);
  71         unsigned int tag_remaining = header.length - APETAG_HEADER_LENGTH;
  72         int i;
  73
  74         if (lseek(fd, -header.length, SEEK_END) < 0)
  75         {
  76             return false;
  77         }
  78
  79         for (i = 0; i < header.item_count; i++)
  80         {
  81             struct apetag_item_header item;
  82             char name[TAG_NAME_LENGTH];
  83             char value[TAG_VALUE_LENGTH];
  84             long r;
  85
  86             if (tag_remaining < sizeof(item))
  87             {
  88                 break;
  89             }
  90
  91             if (ecread(fd, &item, 1, APETAG_ITEM_HEADER_FORMAT, IS_BIG_ENDIAN) < (long) sizeof(item))
  92             {
  93                 return false;
  94             }
  95
  96             tag_remaining -= sizeof(item);
  97             r = read_string(fd, name, sizeof(name), 0, tag_remaining);
  98
  99             if (r == -1)
 100             {
 101                 return false;
 102             }
 103
 104             tag_remaining -= r + item.length;
 105
 106             if ((item.flags & APETAG_ITEM_TYPE_MASK) == 0)
 107             {
 108                 long len;
 109
 110                 if (read_string(fd, value, sizeof(value), -1, item.length)
 111                     != item.length)
 112                 {
 113                     return false;
 114                 }
 115
 116                 len = parse_tag(name, value, id3, buf, buf_remaining,
 117                     TAGTYPE_APE);
 118                 buf += len;
 119                 buf_remaining -= len;
 120             }
 121             else
 122             {
 123                 if (lseek(fd, item.length, SEEK_CUR) < 0)
 124                 {
 125                     return false;
 126                 }
 127             }
 128         }
 129     }
 130
 131     return true;
 132 }