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 #ifdef HAVE_ALBUMART
  39 /* The AA header consists of the pseudo filename "Album Cover (Front).ext"
  40  * whereas ".ext" is the file extension. For now ".jpg" and ".png" are
  41  * supported by this APE metadata parser. Therefore the length is 22. */
  42 #define APETAG_AA_HEADER_LENGTH     22
  43 #endif
  44
  45 struct apetag_header
  46 {
  47     char id[8];
  48     long version;
  49     long length;
  50     long item_count;
  51     long flags;
  52     char reserved[8];
  53 };
  54
  55 struct apetag_item_header
  56 {
  57     long length;
  58     long flags;
  59 };
  60
  61 /* Read the items in an APEV2 tag. Only looks for a tag at the end of a
  62  * file. Returns true if a tag was found and fully read, false otherwise.
  63  */
  64 bool read_ape_tags(int fd, struct mp3entry* id3)
  65 {
  66     struct apetag_header header;
  67
  68     if ((lseek(fd, -APETAG_HEADER_LENGTH, SEEK_END) < 0)
  69         || (ecread(fd, &header, 1, APETAG_HEADER_FORMAT, IS_BIG_ENDIAN)
  70             != APETAG_HEADER_LENGTH)
  71         || (memcmp(header.id, "APETAGEX", sizeof(header.id))))
  72     {
  73         return false;
  74     }
  75
  76     if ((header.version == 2000) && (header.item_count > 0)
  77         && (header.length > APETAG_HEADER_LENGTH))
  78     {
  79         char *buf = id3->id3v2buf;
  80         unsigned int buf_remaining = sizeof(id3->id3v2buf)
  81             + sizeof(id3->id3v1buf);
  82         unsigned int tag_remaining = header.length - APETAG_HEADER_LENGTH;
  83         int i;
  84
  85         if (lseek(fd, -header.length, SEEK_END) < 0)
  86         {
  87             return false;
  88         }
  89
  90         for (i = 0; i < header.item_count; i++)
  91         {
  92             struct apetag_item_header item;
  93             char name[TAG_NAME_LENGTH];
  94             char value[TAG_VALUE_LENGTH];
  95             long r;
  96
  97             if (tag_remaining < sizeof(item))
  98             {
  99                 break;
 100             }
 101
 102             if (ecread(fd, &item, 1, APETAG_ITEM_HEADER_FORMAT, IS_BIG_ENDIAN)
 103                 < (long) sizeof(item))
 104             {
 105                 return false;
 106             }
 107
 108             tag_remaining -= sizeof(item);
 109             r = read_string(fd, name, sizeof(name), 0, tag_remaining);
 110
 111             if (r == -1)
 112             {
 113                 return false;
 114             }
 115
 116             tag_remaining -= r + item.length;
 117
 118             if ((item.flags & APETAG_ITEM_TYPE_MASK) == 0)
 119             {
 120                 long len;
 121
 122                 if (read_string(fd, value, sizeof(value), -1, item.length)
 123                     != item.length)
 124                 {
 125                     return false;
 126                 }
 127
 128                 len = parse_tag(name, value, id3, buf, buf_remaining,
 129                     TAGTYPE_APE);
 130                 buf += len;
 131                 buf_remaining -= len;
 132             }
 133             else
 134             {
 135 #ifdef HAVE_ALBUMART
 136                 if (strcasecmp(name, "cover art (front)") == 0)
 137                 {
 138                     /* Allow to read at least APETAG_AA_HEADER_LENGTH bytes. */
 139                     r = read_string(fd, name, sizeof(name), 0, APETAG_AA_HEADER_LENGTH);
 140                     if (r == -1)
 141                     {
 142                         return false;
 143                     }
 144
 145                     /* Gather the album art format from the pseudo file name. */
 146                     id3->albumart.type = AA_TYPE_UNKNOWN;
 147                     if      (strcasecmp(name, "cover art (front).jpg") == 0)
 148                     {
 149                         id3->albumart.type = AA_TYPE_JPG;
 150                     }
 151                     else if (strcasecmp(name, "cover art (front).png") == 0)
 152                     {
 153                         id3->albumart.type = AA_TYPE_PNG;
 154                     }
 155
 156                     /* Set the album art size and position. */
 157                     if (id3->albumart.type != AA_TYPE_UNKNOWN)
 158                     {
 159                         id3->albumart.pos  = lseek(fd, 0, SEEK_CUR);
 160                         id3->albumart.size = item.length - r;
 161                         id3->embed_albumart = true;
 162                     }
 163
 164                     /* Seek back to this APE items begin. */
 165                     if (lseek(fd, -r, SEEK_CUR) < 0)
 166                     {
 167                         return false;
 168                     }
 169                 }
 170 #endif
 171                 /* Seek to the next APE item. */
 172                 if (lseek(fd, item.length, SEEK_CUR) < 0)
 173                 {
 174                     return false;
 175                 }
 176             }
 177         }
 178     }
 179
 180     return true;
 181 }