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: utf16.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 # include <stdlib.h>
29
30 # include "id3tag.h"
31 # include "utf16.h"
32 # include "ucs4.h"
33
34 /*
35 * NAME: utf16->length()
36 * DESCRIPTION: return the number of ucs4 chars represented by a utf16 string
37 */
id3_utf16_length(id3_utf16_t const * utf16)38 id3_length_t id3_utf16_length(id3_utf16_t const *utf16)
39 {
40 id3_length_t length = 0;
41
42 while (*utf16) {
43 if (utf16[0] < 0xd800 || utf16[0] > 0xdfff)
44 ++length;
45 else if (utf16[0] >= 0xd800 && utf16[0] <= 0xdbff &&
46 utf16[1] >= 0xdc00 && utf16[1] <= 0xdfff) {
47 ++length;
48 ++utf16;
49 }
50
51 ++utf16;
52 }
53
54 return length;
55 }
56
57 /*
58 * NAME: utf16->size()
59 * DESCRIPTION: return the encoding size of a utf16 string
60 */
id3_utf16_size(id3_utf16_t const * utf16)61 id3_length_t id3_utf16_size(id3_utf16_t const *utf16)
62 {
63 id3_utf16_t const *ptr = utf16;
64
65 while (*ptr)
66 ++ptr;
67
68 return ptr - utf16 + 1;
69 }
70
71 /*
72 * NAME: utf16->ucs4duplicate()
73 * DESCRIPTION: duplicate and decode a utf16 string into ucs4
74 */
id3_utf16_ucs4duplicate(id3_utf16_t const * utf16)75 id3_ucs4_t *id3_utf16_ucs4duplicate(id3_utf16_t const *utf16)
76 {
77 id3_ucs4_t *ucs4;
78
79 ucs4 = malloc((id3_utf16_length(utf16) + 1) * sizeof(*ucs4));
80 if (ucs4)
81 id3_utf16_decode(utf16, ucs4);
82
83 return release(ucs4);
84 }
85
86 /*
87 * NAME: utf16->decodechar()
88 * DESCRIPTION: decode a series of utf16 chars into a single ucs4 char
89 */
id3_utf16_decodechar(id3_utf16_t const * utf16,id3_ucs4_t * ucs4)90 id3_length_t id3_utf16_decodechar(id3_utf16_t const *utf16, id3_ucs4_t *ucs4)
91 {
92 id3_utf16_t const *start = utf16;
93
94 while (1) {
95 if (utf16[0] < 0xd800 || utf16[0] > 0xdfff) {
96 *ucs4 = utf16[0];
97 return utf16 - start + 1;
98 }
99 else if (utf16[0] >= 0xd800 && utf16[0] <= 0xdbff &&
100 utf16[1] >= 0xdc00 && utf16[1] <= 0xdfff) {
101 *ucs4 = (((utf16[0] & 0x03ffL) << 10) |
102 ((utf16[1] & 0x03ffL) << 0)) + 0x00010000L;
103 return utf16 - start + 2;
104 }
105
106 ++utf16;
107 }
108 }
109
110 /*
111 * NAME: utf16->encodechar()
112 * DESCRIPTION: encode a single ucs4 char into a series of up to 2 utf16 chars
113 */
id3_utf16_encodechar(id3_utf16_t * utf16,id3_ucs4_t ucs4)114 id3_length_t id3_utf16_encodechar(id3_utf16_t *utf16, id3_ucs4_t ucs4)
115 {
116 if (ucs4 < 0x00010000L) {
117 utf16[0] = ucs4;
118
119 return 1;
120 }
121 else if (ucs4 < 0x00110000L) {
122 ucs4 -= 0x00010000L;
123
124 utf16[0] = ((ucs4 >> 10) & 0x3ff) | 0xd800;
125 utf16[1] = ((ucs4 >> 0) & 0x3ff) | 0xdc00;
126
127 return 2;
128 }
129
130 /* default */
131
132 return id3_utf16_encodechar(utf16, ID3_UCS4_REPLACEMENTCHAR);
133 }
134
135 /*
136 * NAME: utf16->decode()
137 * DESCRIPTION: decode a complete utf16 string into a ucs4 string
138 */
id3_utf16_decode(id3_utf16_t const * utf16,id3_ucs4_t * ucs4)139 void id3_utf16_decode(id3_utf16_t const *utf16, id3_ucs4_t *ucs4)
140 {
141 do
142 utf16 += id3_utf16_decodechar(utf16, ucs4);
143 while (*ucs4++);
144 }
145
146 /*
147 * NAME: utf16->encode()
148 * DESCRIPTION: encode a complete ucs4 string into a utf16 string
149 */
id3_utf16_encode(id3_utf16_t * utf16,id3_ucs4_t const * ucs4)150 void id3_utf16_encode(id3_utf16_t *utf16, id3_ucs4_t const *ucs4)
151 {
152 do
153 utf16 += id3_utf16_encodechar(utf16, *ucs4);
154 while (*ucs4++);
155 }
156
157 /*
158 * NAME: utf16->put()
159 * DESCRIPTION: serialize a single utf16 character
160 */
id3_utf16_put(id3_byte_t ** ptr,id3_utf16_t utf16,enum id3_utf16_byteorder byteorder)161 id3_length_t id3_utf16_put(id3_byte_t **ptr, id3_utf16_t utf16,
162 enum id3_utf16_byteorder byteorder)
163 {
164 if (ptr) {
165 switch (byteorder) {
166 default:
167 case ID3_UTF16_BYTEORDER_BE:
168 (*ptr)[0] = (utf16 >> 8) & 0xff;
169 (*ptr)[1] = (utf16 >> 0) & 0xff;
170 break;
171
172 case ID3_UTF16_BYTEORDER_LE:
173 (*ptr)[0] = (utf16 >> 0) & 0xff;
174 (*ptr)[1] = (utf16 >> 8) & 0xff;
175 break;
176 }
177
178 *ptr += 2;
179 }
180
181 return 2;
182 }
183
184 /*
185 * NAME: utf16->get()
186 * DESCRIPTION: deserialize a single utf16 character
187 */
id3_utf16_get(id3_byte_t const ** ptr,enum id3_utf16_byteorder byteorder)188 id3_utf16_t id3_utf16_get(id3_byte_t const **ptr,
189 enum id3_utf16_byteorder byteorder)
190 {
191 id3_utf16_t utf16;
192
193 switch (byteorder) {
194 default:
195 case ID3_UTF16_BYTEORDER_BE:
196 utf16 =
197 ((*ptr)[0] << 8) |
198 ((*ptr)[1] << 0);
199 break;
200
201 case ID3_UTF16_BYTEORDER_LE:
202 utf16 =
203 ((*ptr)[0] << 0) |
204 ((*ptr)[1] << 8);
205 break;
206 }
207
208 *ptr += 2;
209
210 return utf16;
211 }
212
213 /*
214 * NAME: utf16->serialize()
215 * DESCRIPTION: serialize a ucs4 string using utf16 encoding
216 */
id3_utf16_serialize(id3_byte_t ** ptr,id3_ucs4_t const * ucs4,enum id3_utf16_byteorder byteorder,int terminate)217 id3_length_t id3_utf16_serialize(id3_byte_t **ptr, id3_ucs4_t const *ucs4,
218 enum id3_utf16_byteorder byteorder,
219 int terminate)
220 {
221 id3_length_t size = 0;
222 id3_utf16_t utf16[2], *out;
223
224 if (byteorder == ID3_UTF16_BYTEORDER_ANY)
225 size += id3_utf16_put(ptr, 0xfeff, byteorder);
226
227 while (*ucs4) {
228 switch (id3_utf16_encodechar(out = utf16, *ucs4++)) {
229 case 2: size += id3_utf16_put(ptr, *out++, byteorder);
230 case 1: size += id3_utf16_put(ptr, *out++, byteorder);
231 case 0: break;
232 }
233 }
234
235 if (terminate)
236 size += id3_utf16_put(ptr, 0, byteorder);
237
238 return size;
239 }
240
241 /*
242 * NAME: utf16->deserialize()
243 * DESCRIPTION: deserialize a ucs4 string using utf16 encoding
244 */
id3_utf16_deserialize(id3_byte_t const ** ptr,id3_length_t length,enum id3_utf16_byteorder byteorder)245 id3_ucs4_t *id3_utf16_deserialize(id3_byte_t const **ptr, id3_length_t length,
246 enum id3_utf16_byteorder byteorder)
247 {
248 id3_byte_t const *end;
249 id3_utf16_t *utf16ptr, *utf16;
250 id3_ucs4_t *ucs4;
251
252 end = *ptr + (length & ~1);
253
254 utf16 = malloc((length / 2 + 1) * sizeof(*utf16));
255 if (utf16 == 0)
256 return 0;
257
258 if (byteorder == ID3_UTF16_BYTEORDER_ANY && end - *ptr > 0) {
259 switch (((*ptr)[0] << 8) |
260 ((*ptr)[1] << 0)) {
261 case 0xfeff:
262 byteorder = ID3_UTF16_BYTEORDER_BE;
263 *ptr += 2;
264 break;
265
266 case 0xfffe:
267 byteorder = ID3_UTF16_BYTEORDER_LE;
268 *ptr += 2;
269 break;
270 }
271 }
272
273 utf16ptr = utf16;
274 while (end - *ptr > 0 && (*utf16ptr = id3_utf16_get(ptr, byteorder)))
275 ++utf16ptr;
276
277 *utf16ptr = 0;
278
279 ucs4 = malloc((id3_utf16_length(utf16) + 1) * sizeof(*ucs4));
280 if (ucs4)
281 id3_utf16_decode(utf16, ucs4);
282
283 free(utf16);
284
285 return ucs4;
286 }
287