The present invention is directed to a video unified codec device and its method. According to an embodiment of this invention, the unified codec device comprises parsing and decoding functional units (PD FUs) extracting and grouping context information, control signals, and data in bit streams inputted according to different syntax data per codec, macro-block-based functional units (MB-based FUs) unified based on block-based process units of each codec, for decoding data outputted from PD FUs, and a global control unit (GCU) for controlling MB-based FUs grouped after corresponding control signals and context information received from PD FUs to each codec and processing. By this invention, a new concept and structure of unified codec corresponding to similarities, differences, and considerations between different codecs can be presented.