comparison src/libid3tag-0.15.1b/utf16.c @ 0:c7265573341e

Import initial set of sources

+/*
+ * 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;
+}