private void decodeNextByte() throws IOException {
	if (_nextByte == ArithCodeModel.EOF) return;
	if (_decoder.endOfStream()) { _nextByte = ArithCodeModel.EOF; return; }
	while (true) {
	    _nextByte = _model.pointToSymbol(_decoder.getCurrentSymbolCount(_model.totalCount()));
	    _model.interval(_nextByte,_interval);
	    _decoder.removeSymbolFromStream(_interval); 
	    if (_nextByte != ArithCodeModel.ESCAPE) return;
	}
    }