A method for controlling an arithmetic codec context is disclosed. The method may include the steps of (A) reading a current value indicating one of a first condition and a second condition corresponding to a current context of a plurality of predetermined contexts, (B) generating an input state matching (i) an initial state in response to the first condition and (ii) an output state in response to the second condition, wherein the initial state has a predetermined value and the output state has a value generated by the method before receiving the current context and (C) generating a current output state by performing an arithmetic code operation on an input signal using the input state.