A method and apparatus for reducing the size of data rate fluctuations that occur in forming a multiplex of a set of program streams, each program stream in said set being decodeable by a corresponding decoder, each corresponding decoder including a corresponding decoder buffer, said decoder buffers having a maximum allowable size, said method comprising varying the formation of the different program streams in said set to minimize the memory requirement of the decoder buffers. In one embodiment, for the case of the streams being segments of a program, varying includes varying the segment length. In another embodiment, varying includes adjusting the relative alignment of the program streams. Different embodiments of adjusting include inserting program material such as a pause at selected points in time, causing decoder buffers to underflow at selected points in time, and varying the rate of decoding and display at selected points in time.