ut interface</h4>
    <p>This class implements input from file.</p>
    <p><strong>Class methods:</strong></p>
    <dl>
      <dt><strong> LibRaw_bigfile_datastream(const char *fname) </strong></dt>
      <dd>This constructor creates <strong>LibRaw_bigfile_datastream</strong>
        object from file <strong>fname</strong>.<br>
        Unfortunately, C++ constructor cannot return an error. So if bad
        filename passed (e.g. nonexistent file) object is created as non-valid
        (valid() call returns 