The paper gives a short overview on the new feature of the recent MPEG-4 standard, namely interactive facilitation of multimedia contents. Some experiments on dealing with BIFS and MPEG-J - the two main motors enabling the interactivity in MPEG-4 - are presented. These experiments serve for two targets. First, they demonstrate a very perspective capability of MPEG-4 based multimedia contents, which are not only flexible in composition but also make interaction with viewer possible. Next, they expose a gap occurring in merging the computing and broadcasting technology in MPEG-4, namely temporal constraint versus random access. The work also outlines some solution to overcome this problem. The goal is to improve the performance of the interactivity enabling feature so that MPEG-4 standard actually integrates the computing capability into compression technique, enabling the generation of sophisticated multimedia scene.