engine the coding engine 148 may encode the signal int 1 using the particular context to generate the compressed data 108 the coding engine 148 may also generate a signal e g pdu back to the probability estimation circuit 146 the signal pdu may carry probability estimation update information to allow for adaptation over time to changing context referring to fig3 a partial block diagram for an example implementation of the decoder 126 is shown in accordance with a preferred embodiment of the present invention the decoder or system 126 generally comprises a circuit or module 150 a circuit or module 152 a circuit or module 154 a circuit or module 156 and a circuit or module 158 the decoder 126 may receive the bitstream via the link 124 the decoder 126 may present a signal e g dout the signal dout may carry a sequence of decoded symbols used in decoding reference picture motion vector residuals and the like the circuit 150 may be referred to as another context modeling circuit the context modeling circuit 150 may be configured to generate a second signal ctxidxinc for use in decoding the symbols the signal ctxidxinc may be presented to the circuit 154 the circuit 154 may be referred to as a cabac arithmetic decoding engine the cabac arithmetic decoding engine 154 may be configured to perform a cabac decoding operation on the signal din based on the context identified in the signal.