A unified codec device and a method thereof are disclosed. The unified codec device in accordance with an embodiment of the present invention comprises a decoding control unit, which sets a connection relation of functional units by interpreting connection information from an inputted universal bitstream or data, and a functional group, which consists of a plurality of functional units and in which functional units corresponding to a sequential start control of the decoding control unit are sequentially activated to process a bitstream or the data, using the control parameter, to output the inputted bitstream as image data. Using the functional unit recombination technique in accordance with the present invention, the bitstreams based on various decoding standards can be encoded/decoded without restriction.