1. A method for performing parallel coding with ordered entropy slices, the method comprising: providing a plurality of entropy slices within a picture with a causal criterion on processing order to a plurality of processing elements, wherein each entropy slice comprises a plurality of blocks, a bus is in-between for communication between a controller and the processing elements; and respectively starting each of the processing elements to perform a Context-based Adaptive Binary Arithmetic Coding (CABAC) processing of a coding procedure for a corresponding entropy slice according to the causal criterion; wherein start time points of the CABAC processing of a first entropy slice and the CABAC processing of a second entropy slice positioned below the first entropy slice are different, and the processing elements of the CABAC processing for the first entropy slice and the CABAC processing for the second entropy slice are different, and the CABAC processing for the first entropy slice and the CABAC processing for the second entropy slices are performed in parallel during at least a portion of processing time, wherein the CABAC processing comprises a plurality of processes, and both of the processing element performing CABAC processing on the first entropy slice and the processing element performing CABAC processing on the second entropy slice perform a same one of the plurality of processes of the CABAC processing in parallel.