A decoder receives a bitstream containing quantized coefficients representative of blocks of video representative of a plurality of pixels and decodes the bitstream using context adaptive binary arithmetic coding that includes at least two decoding modes, the first mode decoding the bitstream based upon a probability estimate which is based upon at least one of spatially and temporally adjacent syntax element values to a current syntax element being decoded, the second mode decoding the bitstream not based upon a probability estimate based upon other syntax elements to the current syntax element being decoded. The coding decodes the current syntax element using the first mode if the current syntax element is intra-coded and selecting between sets probable modes with different probabilities. The coding decodes the current syntax element using the second mode if the current syntax element is intra-coded and if selecting among one of the second set of probable modes.