create iso using imapi

create_iso.cpp

#include <string>
#include <atlbase.h>
#include <imapi2fs.h>

void create_iso( std::wstring_view src, std::wstring_view iso_path )
{
    HRESULT hr;
    IFileSystemImage* fsimg;
    IFsiDirectoryItem* fsdir;
    IFileSystemImageResult* fsresult;
    IStream* img;
    IStream* filestream;

    hr = CoCreateInstance( __uuidof( MsftFileSystemImage ),
                           NULL,
                           CLSCTX_INPROC_SERVER,
                           __uuidof( IFileSystemImage ),
                           ( LPVOID* ) &fsimg );
    if ( SUCCEEDED( hr ) )
    {
        fsimg->get_Root( &fsdir );

        fsdir->AddTree( CComBSTR( src.data() ), VARIANT_TRUE );

        hr = fsimg->CreateResultImage( &fsresult );
        if ( SUCCEEDED( hr ) )
        {
            fsresult->get_ImageStream( &img );
            if ( SUCCEEDED( hr ) )
            {
                STATSTG statstg;
                ULARGE_INTEGER rd;
                ULARGE_INTEGER wr;

                SHCreateStreamOnFileEx( iso_path.data(),
                                        STGM_READWRITE,
                                        FILE_ATTRIBUTE_NORMAL,
                                        TRUE,
                                        NULL,
                                        &filestream );

                img->Stat( &statstg, STATFLAG_DEFAULT );
                img->CopyTo( filestream, statstg.cbSize, &rd, &wr );
                filestream->Release();
                img->Release();
            }

            fsresult->Release();
        }

        fsimg->Release();
    }
}

CoInitializeEx(0);
create_iso(R("d:\in\testdir"), R("d:\out\test.iso"));
//
// OR...
//
create_iso(R("d:\in\testfile.ext"), R("d:\out\test.iso"));
CoUninitialize();