release/src/router/libid3tag/genre.c

   1 /*
   2  * libid3tag - ID3 tag manipulation library
   3  * Copyright (C) 2000-2004 Underbit Technologies, Inc.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  *
  19  * $Id: genre.c,v 1.8 2004/01/23 09:41:32 rob Exp $
  20  */
  21
  22 # ifdef HAVE_CONFIG_H
  23 #  include "config.h"
  24 # endif
  25
  26 # include "global.h"
  27
  28 # include "id3tag.h"
  29 # include "ucs4.h"
  30
  31 /* genres are stored in ucs4 format */
  32 # include "genre.dat"
  33
  34 # define NGENRES  (sizeof(genre_table) / sizeof(genre_table[0]))
  35
  36 /*
  37  * NAME:        genre->index()
  38  * DESCRIPTION: return an ID3v1 genre string indexed by number
  39  */
  40 id3_ucs4_t const *id3_genre_index(unsigned int index)
  41 {
  42   return (index < NGENRES) ? genre_table[index] : 0;
  43 }
  44
  45 /*
  46  * NAME:        genre->name()
  47  * DESCRIPTION: translate an ID3v2 genre number/keyword to its full name
  48  */
  49 id3_ucs4_t const *id3_genre_name(id3_ucs4_t const *string)
  50 {
  51   id3_ucs4_t const *ptr;
  52   static id3_ucs4_t const genre_remix[] = { 'R', 'e', 'm', 'i', 'x', 0 };
  53   static id3_ucs4_t const genre_cover[] = { 'C', 'o', 'v', 'e', 'r', 0 };
  54   unsigned long number;
  55
  56   if (string == 0 || *string == 0)
  57     return id3_ucs4_empty;
  58
  59   if (string[0] == 'R' && string[1] == 'X' && string[2] == 0)
  60     return genre_remix;
  61   if (string[0] == 'C' && string[1] == 'R' && string[2] == 0)
  62     return genre_cover;
  63
  64   for (ptr = string; *ptr; ++ptr) {
  65     if (*ptr < '0' || *ptr > '9')
  66       return string;
  67   }
  68
  69   number = id3_ucs4_getnumber(string);
  70
  71   return (number < NGENRES) ? genre_table[number] : string;
  72 }
  73
  74 /*
  75  * NAME:        translate()
  76  * DESCRIPTION: return a canonicalized character for testing genre equivalence
  77  */
  78 static
  79 id3_ucs4_t translate(id3_ucs4_t ch)
  80 {
  81   if (ch) {
  82     if (ch >= 'A' && ch <= 'Z')
  83       ch += 'a' - 'A';
  84
  85     if (ch < 'a' || ch > 'z')
  86       ch = ID3_UCS4_REPLACEMENTCHAR;
  87   }
  88
  89   return ch;
  90 }
  91
  92 /*
  93  * NAME:        compare()
  94  * DESCRIPTION: test two ucs4 genre strings for equivalence
  95  */
  96 static
  97 int compare(id3_ucs4_t const *str1, id3_ucs4_t const *str2)
  98 {
  99   id3_ucs4_t c1, c2;
 100
 101   if (str1 == str2)
 102     return 1;
 103
 104   do {
 105     do
 106       c1 = translate(*str1++);
 107     while (c1 == ID3_UCS4_REPLACEMENTCHAR);
 108
 109     do
 110       c2 = translate(*str2++);
 111     while (c2 == ID3_UCS4_REPLACEMENTCHAR);
 112   }
 113   while (c1 && c1 == c2);
 114
 115   return c1 == c2;
 116 }
 117
 118 /*
 119  * NAME:        genre->number()
 120  * DESCRIPTION: translate an ID3v2 genre name/number to its ID3v1 index number
 121  */
 122 int id3_genre_number(id3_ucs4_t const *string)
 123 {
 124   id3_ucs4_t const *ptr;
 125   int i;
 126
 127   if (string == 0 || *string == 0)
 128     return -1;
 129
 130   for (ptr = string; *ptr; ++ptr) {
 131     if (*ptr < '0' || *ptr > '9')
 132       break;
 133   }
 134
 135   if (*ptr == 0) {
 136     unsigned long number;
 137
 138     number = id3_ucs4_getnumber(string);
 139
 140     return (number <= 0xff) ? number : -1;
 141   }
 142
 143   for (i = 0; i < NGENRES; ++i) {
 144     if (compare(string, genre_table[i]))
 145       return i;
 146   }
 147
 148   /* no equivalent */
 149
 150   return -1;
 151 }