/*
* libid3tag - ID3 tag manipulation library
* Copyright (C) 2000-2004 Underbit Technologies, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: utf16.c,v 1.9 2004/01/23 09:41:32 rob Exp $
*/
# ifdef HAVE_CONFIG_H
# include "config.h"
# endif
# include "global.h"
# include <stdlib.h>
# include "id3tag.h"
# include "utf16.h"
# include "ucs4.h"
/*
* NAME: utf16->length()
* DESCRIPTION: return the number of ucs4 chars represented by a utf16 string
*/
id3_length_t id3_utf16_length(id3_utf16_t const *utf16)
{
id3_length_t length = 0;
while (*utf16) {
if (utf16[0] < 0xd800 || utf16[0] > 0xdfff)
++length;
else if (utf16[0] >= 0xd800 && utf16[0] <= 0xdbff &&
utf16[1] >= 0xdc00 && utf16[1] <= 0xdfff) {
++length;
++utf16;
}
++utf16;
}
return length;
}
/*
* NAME: utf16->size()
* DESCRIPTION: return the encoding size of a utf16 string
*/
id3_length_t id3_utf16_size(id3_utf16_t const *utf16)
{
id3_utf16_t const *ptr = utf16;
while (*ptr)
++ptr;
return ptr - utf16 + 1;
}
/*
* NAME: utf16->ucs4duplicate()
* DESCRIPTION: duplicate and decode a utf16 string into ucs4
*/
id3_ucs4_t *id3_utf16_ucs4duplicate(id3_utf16_t const *utf16)
{
id3_ucs4_t *ucs4;
ucs4 = malloc((id3_utf16_length(utf16) + 1) * sizeof(*ucs4));
if (ucs4)
id3_utf16_decode(utf16, ucs4);
return release(ucs4);
}
/*
* NAME: utf16->decodechar()
* DESCRIPTION: decode a series of utf16 chars into a single ucs4 char
*/
id3_length_t id3_utf16_decodechar(id3_utf16_t const *utf16, id3_ucs4_t *ucs4)
{
id3_utf16_t const *start = utf16;
while (1) {
if (utf16[0] < 0xd800 || utf16[0] > 0xdfff) {
*ucs4 = utf16[0];
return utf16 - start + 1;
}
else if (utf16[0] >= 0xd800 && utf16[0] <= 0xdbff &&
utf16[1] >= 0xdc00 && utf16[1] <= 0xdfff) {
*ucs4 = (((utf16[0] & 0x03ffL) << 10) |
((utf16[1] & 0x03ffL) << 0)) + 0x00010000L;
return utf16 - start + 2;
}
++utf16;
}
}
/*
* NAME: utf16->encodechar()
* DESCRIPTION: encode a single ucs4 char into a series of up to 2 utf16 chars
*/
id3_length_t id3_utf16_encodechar(id3_utf16_t *utf16, id3_ucs4_t ucs4)
{
if (ucs4 < 0x00010000L) {
utf16[0] = ucs4;
return 1;
}
else if (ucs4 < 0x00110000L) {
ucs4 -= 0x00010000L;
utf16[0] = ((ucs4 >> 10) & 0x3ff) | 0xd800;
utf16[1] = ((ucs4 >> 0) & 0x3ff) | 0xdc00;
return 2;
}
/* default */
return id3_utf16_encodechar(utf16, ID3_UCS4_REPLACEMENTCHAR);
}
/*
* NAME: utf16->decode()
* DESCRIPTION: decode a complete utf16 string into a ucs4 string
*/
void id3_utf16_decode(id3_utf16_t const *utf16, id3_ucs4_t *ucs4)
{
do
utf16 += id3_utf16_decodechar(utf16, ucs4);
while (*ucs4++);
}
/*
* NAME: utf16->encode()
* DESCRIPTION: encode a complete ucs4 string into a utf16 string
*/
void id3_utf16_encode(id3_utf16_t *utf16, id3_ucs4_t const *ucs4)
{
do
utf16 += id3_utf16_encodechar(utf16, *ucs4);
while (*ucs4++);
}
/*
* NAME: utf16->put()
* DESCRIPTION: serialize a single utf16 character
*/
id3_length_t id3_utf16_put(id3_byte_t **ptr, id3_utf16_t utf16,
enum id3_utf16_byteorder byteorder)
{
if (ptr) {
switch (byteorder) {
default:
case ID3_UTF16_BYTEORDER_BE:
(*ptr)[0] = (utf16 >> 8) & 0xff;
(*ptr)[1] = (utf16 >> 0) & 0xff;
break;
case ID3_UTF16_BYTEORDER_LE:
(*ptr)[0] = (utf16 >> 0) & 0xff;
(*ptr)[1] = (utf16 >> 8) & 0xff;
break;
}
*ptr += 2;
}
return 2;
}
/*
* NAME: utf16->get()
* DESCRIPTION: deserialize a single utf16 character
*/
id3_utf16_t id3_utf16_get(id3_byte_t const **ptr,
enum id3_utf16_byteorder byteorder)
{
id3_utf16_t utf16;
switch (byteorder) {
default:
case ID3_UTF16_BYTEORDER_BE:
utf16 =
((*ptr)[0] << 8) |
((*ptr)[1] << 0);
break;
case ID3_UTF16_BYTEORDER_LE:
utf16 =
((*ptr)[0] << 0) |
((*ptr)[1] << 8);
break;
}
*ptr += 2;
return utf16;
}
/*
* NAME: utf16->serialize()
* DESCRIPTION: serialize a ucs4 string using utf16 encoding
*/
id3_length_t id3_utf16_serialize(id3_byte_t **ptr, id3_ucs4_t const *ucs4,
enum id3_utf16_byteorder byteorder,
int terminate)
{
id3_length_t size = 0;
id3_utf16_t utf16[2], *out;
if (byteorder == ID3_UTF16_BYTEORDER_ANY)
size += id3_utf16_put(ptr, 0xfeff, byteorder);
while (*ucs4) {
switch (id3_utf16_encodechar(out = utf16, *ucs4++)) {
case 2: size += id3_utf16_put(ptr, *out++, byteorder);
case 1: size += id3_utf16_put(ptr, *out++, byteorder);
case 0: break;
}
}
if (terminate)
size += id3_utf16_put(ptr, 0, byteorder);
return size;
}
/*
* NAME: utf16->deserialize()
* DESCRIPTION: deserialize a ucs4 string using utf16 encoding
*/
id3_ucs4_t *id3_utf16_deserialize(id3_byte_t const **ptr, id3_length_t length,
enum id3_utf16_byteorder byteorder)
{
id3_byte_t const *end;
id3_utf16_t *utf16ptr, *utf16;
id3_ucs4_t *ucs4;
end = *ptr + (length & ~1);
utf16 = malloc((length / 2 + 1) * sizeof(*utf16));
if (utf16 == 0)
return 0;
if (byteorder == ID3_UTF16_BYTEORDER_ANY && end - *ptr > 0) {
switch (((*ptr)[0] << 8) |
((*ptr)[1] << 0)) {
case 0xfeff:
byteorder = ID3_UTF16_BYTEORDER_BE;
*ptr += 2;
break;
case 0xfffe:
byteorder = ID3_UTF16_BYTEORDER_LE;
*ptr += 2;
break;
}
}
utf16ptr = utf16;
while (end - *ptr > 0 && (*utf16ptr = id3_utf16_get(ptr, byteorder)))
++utf16ptr;
*utf16ptr = 0;
ucs4 = malloc((id3_utf16_length(utf16) + 1) * sizeof(*ucs4));
if (ucs4)
id3_utf16_decode(utf16, ucs4);
free(utf16);
return ucs4;
}
