release/src/router/libid3tag/parse.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: parse.c,v 1.9 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 # ifdef HAVE_ASSERT_H
  29 #  include <assert.h>
  30 # endif
  31
  32 # include <stdlib.h>
  33 # include <string.h>
  34
  35 # include "id3tag.h"
  36 # include "parse.h"
  37 # include "latin1.h"
  38 # include "utf16.h"
  39 # include "utf8.h"
  40
  41 signed long id3_parse_int(id3_byte_t const **ptr, unsigned int bytes)
  42 {
  43   signed long value = 0;
  44
  45   assert(bytes >= 1 && bytes <= 4);
  46
  47   if (**ptr & 0x80)
  48     value = ~0;
  49
  50   switch (bytes) {
  51   case 4: value = (value << 8) | *(*ptr)++;
  52   case 3: value = (value << 8) | *(*ptr)++;
  53   case 2: value = (value << 8) | *(*ptr)++;
  54   case 1: value = (value << 8) | *(*ptr)++;
  55   }
  56
  57   return value;
  58 }
  59
  60 unsigned long id3_parse_uint(id3_byte_t const **ptr, unsigned int bytes)
  61 {
  62   unsigned long value = 0;
  63
  64   assert(bytes >= 1 && bytes <= 4);
  65
  66   switch (bytes) {
  67   case 4: value = (value << 8) | *(*ptr)++;
  68   case 3: value = (value << 8) | *(*ptr)++;
  69   case 2: value = (value << 8) | *(*ptr)++;
  70   case 1: value = (value << 8) | *(*ptr)++;
  71   }
  72
  73   return value;
  74 }
  75
  76 unsigned long id3_parse_syncsafe(id3_byte_t const **ptr, unsigned int bytes)
  77 {
  78   unsigned long value = 0;
  79
  80   assert(bytes == 4 || bytes == 5);
  81
  82   switch (bytes) {
  83   case 5: value = (value << 4) | (*(*ptr)++ & 0x0f);
  84   case 4: value = (value << 7) | (*(*ptr)++ & 0x7f);
  85           value = (value << 7) | (*(*ptr)++ & 0x7f);
  86           value = (value << 7) | (*(*ptr)++ & 0x7f);
  87           value = (value << 7) | (*(*ptr)++ & 0x7f);
  88   }
  89
  90   return value;
  91 }
  92
  93 void id3_parse_immediate(id3_byte_t const **ptr, unsigned int bytes,
  94                          char *value)
  95 {
  96   assert(value);
  97   assert(bytes == 8 || bytes == 4 || bytes == 3);
  98
  99   switch (bytes) {
 100   case 8: *value++ = *(*ptr)++;
 101           *value++ = *(*ptr)++;
 102           *value++ = *(*ptr)++;
 103           *value++ = *(*ptr)++;
 104   case 4: *value++ = *(*ptr)++;
 105   case 3: *value++ = *(*ptr)++;
 106           *value++ = *(*ptr)++;
 107           *value++ = *(*ptr)++;
 108   }
 109
 110   *value = 0;
 111 }
 112
 113 id3_latin1_t *id3_parse_latin1(id3_byte_t const **ptr, id3_length_t length,
 114                                int full)
 115 {
 116   id3_byte_t const *end;
 117   int terminated = 0;
 118   id3_latin1_t *latin1;
 119
 120   end = memchr(*ptr, 0, length);
 121   if (end == 0)
 122     end = *ptr + length;
 123   else {
 124     length = end - *ptr;
 125     terminated = 1;
 126   }
 127
 128   latin1 = malloc(length + 1);
 129   if (latin1) {
 130     memcpy(latin1, *ptr, length);
 131     latin1[length] = 0;
 132
 133     if (!full) {
 134       id3_latin1_t *check;
 135
 136       for (check = latin1; *check; ++check) {
 137         if (*check == '\n')
 138           *check = ' ';
 139       }
 140     }
 141   }
 142
 143   *ptr += length + terminated;
 144
 145   return latin1;
 146 }
 147
 148 id3_ucs4_t *id3_parse_string(id3_byte_t const **ptr, id3_length_t length,
 149                              enum id3_field_textencoding encoding, int full)
 150 {
 151   id3_ucs4_t *ucs4 = 0;
 152   enum id3_utf16_byteorder byteorder = ID3_UTF16_BYTEORDER_ANY;
 153
 154   switch (encoding) {
 155   case ID3_FIELD_TEXTENCODING_ISO_8859_1:
 156     ucs4 = id3_latin1_deserialize(ptr, length);
 157     break;
 158
 159   case ID3_FIELD_TEXTENCODING_UTF_16BE:
 160     byteorder = ID3_UTF16_BYTEORDER_BE;
 161   case ID3_FIELD_TEXTENCODING_UTF_16:
 162     ucs4 = id3_utf16_deserialize(ptr, length, byteorder);
 163     break;
 164
 165   case ID3_FIELD_TEXTENCODING_UTF_8:
 166     ucs4 = id3_utf8_deserialize(ptr, length);
 167     break;
 168   }
 169
 170   if (ucs4 && !full) {
 171     id3_ucs4_t *check;
 172
 173     for (check = ucs4; *check; ++check) {
 174       if (*check == '\n')
 175         *check = ' ';
 176     }
 177   }
 178
 179   return ucs4;
 180 }
 181
 182 id3_byte_t *id3_parse_binary(id3_byte_t const **ptr, id3_length_t length)
 183 {
 184   id3_byte_t *data;
 185
 186   if (length == 0)
 187     return malloc(1);
 188
 189   data = malloc(length);
 190   if (data)
 191     memcpy(data, *ptr, length);
 192
 193   *ptr += length;
 194
 195   return data;
 196 }