here - OSTA - Optical Storage Technology Association

6.4 OSTA Compressed Unicode Algorithm
/***********************************************************************
* OSTA compliant Unicode compression, uncompression routines.
* Copyright 1995 Micro Design International, Inc.
* Written by Jason M. Rinn.
* Micro Design International gives permission for the free use of the
* following source code.
*/
#include
/***********************************************************************
* The following two typedef's are to remove compiler dependancies.
* byte needs to be unsigned 8-bit, and unicode_t needs to be
* unsigned 16-bit.
*/
typedef unsigned short unicode_t;
typedef unsigned char byte;
/***********************************************************************
* Takes an OSTA CS0 compressed unicode name, and converts
* it to Unicode.
* The Unicode output will be in the byte order
* that the local compiler uses for 16-bit values.
* NOTE: This routine only performs error checking on the compID.
* It is up to the user to ensure that the unicode buffer is large
* enough, and that the compressed unicode name is correct.
*
* RETURN VALUE
*
* The number of unicode characters which were uncompressed.
* A -1 is returned if the compression ID is invalid.
*/
int UncompressUnicode(
int numberOfBytes, /* (Input) number of bytes read from media. */
byte *UDFCompressed, /* (Input) bytes read from media. */
unicode_t *unicode) /* (Output) uncompressed unicode characters. */
{
unsigned int compID;
int returnValue, unicodeIndex, byteIndex;
/* Use UDFCompressed to store current byte being read. */
compID = UDFCompressed[0];
/* First check for valid compID. */
if (compID != 8 && compID != 16)
{
returnValue = -1;
}
else
{
unicodeIndex = 0;
byteIndex = 1;
/* Loop through all the bytes. */
while (byteIndex < numberOfBytes)
{
if (compID == 16)
{
/*Move the first byte to the high bits of the unicode char. */
unicode[unicodeIndex] = UDFCompressed[byteIndex++]