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 macroblocks (MBs); and respectively starting each of the processing elements to perform a coding procedure for a corresponding entropy slice according to the causal criterion, thereby at least a portion of the processing elements performs the coding procedure in parallel during at least a portion of processing time.