Reducing the number of contexts for adaptive binary arithmetic coding context

A method of encoding video data comprising: selecting (1006) a context of one or more contexts based on a depth of transformation of a transformation unit associated with a block of video data to be encoded, wherein the depth of transformation specifies the current level of subdivision of a block coding unit for coding object processing; encoding (1002) an indicator block coded chroma Cb for the block of video data using adaptive binary arithmetic coding context, CABAC and the selected context in which the display coding block coded chroma Cb comprises the use of a set of context that includes one or more contexts; and encoding (1004) an indicator of Cr chroma coded block using CABAC, where the encoding indicator Cr chroma coded block comprises using the same set of context indicator Cb chroma coded block.