class FSCRT_BSTR(Structure):
    _fields_ = [("str", c_char_p),
                ("len", c_uint)]
    def __init__(self, s=None):
        if type(s) is str:
            su8 = s.encode()
            self.str, self.len = c_char_p(su8), c_uint(len(su8))
        else:
            self.str, self.len = cast(create_string_buffer(s), c_char_p), c_uint(s)
    def text(self):
        if self.str:
            return self.str.decode()

test = FSCRT_BSTR(1024)
#FS_RESULT FSPDF_TextObject_GetUnicodeString(FSCRT_PAGE page, FSPDF_PAGEOBJECT textObj, FSCRT_BSTR * unicodeStr )
print(hdll.FSPDF_TextObject_GetUnicodeString(Page, obj, byref(test)))

---------------
print(hdll.FSPDF_TextObject_GetUnicodeString(Page, obj, byref(test)))
OSError: exception: access violation reading 0x00000000019C2F68