Unexpected XMP_Error Invalid UTF-8 data byte

Question

Hi all,
I'm using the XMP SDK 4.4.2 and with it the sample application "xmpcommands". This one is extremely helpful - but it fails when using files that have Umlauts(öäü) in the name. When calling, i.e.
xmpcommand.exe get c:\Fileöäü.jpg
the command returns:
Unexpected XMP_Error Invalid UTF-8 data byte
As soon as I remove the umlauts all is fine. I tracked to problem down to the function ToUTF16Native called from GetFileMode in xmpfiles_impl.cpp:
    FileMode GetFileMode ( const char * path )
        std::string utf16;    // GetFileAttributes wants native UTF-16.
        ToUTF16Native ( (UTF8Unit*)path, strlen(path), &utf16 );
        utf16.append ( 2, '\0' );    // Make sure there are at least 2 final zero bytes.
It seems that the file path is NOT UTF8 encoded. This very likely as I'm working on Windows and there the command line encoding is ANSI.
Is there something special I need to set when compiling on Windows?
Does anyone have a solution for this?
[UPDATE]
I've converted the file path to UTF8 and now this error does not occure BUT now I get the error, that the file was not found! Grrr.....
Cheers & THANKS,
Jens
www.finalcandidate.com

Answer 1

Hi,
Input to OpenFile() function needs to be a UTF8 string. "flówér.jpg" is in WinANSI, and needs to be converted to UTF8 string so that OpenFile can correctly find the file.
For example, on Windows OS, you need to define a function as:
void WinEncodingToUTF8 ( UINT codePage, const XMP_Uns8 * hostPtr, size_t hostLen, std::string * utf8 )
int utf16Len = MultiByteToWideChar ( codePage, 0, (LPCSTR)hostPtr, (int)hostLen, 0, 0 );
std::vector<UTF16Unit> utf16 ( utf16Len, 0 );   // MultiByteToWideChar returns native UTF-16.
(void) MultiByteToWideChar ( codePage, 0, (LPCSTR)hostPtr, (int)hostLen, (LPWSTR)&utf16[0], utf16Len );
FromUTF16Native ( &utf16[0], (int)utf16Len, utf8 );
This function requires a function which is present in the file "UnicodeConversions.cpp". So you need to include a file "source/UnicodeConversions.hpp" in your project.
The sample usage could be:
std::string outputPath;
WinEncodingToUTF8( 1252, (const XMP_Uns8 *)inputFile.c_str(), inputFile.size(), &outputPath );