system multiplexed stream is formed the system multiplexed stream is transmitted through a transmission media 150 a demultiplexer and system decoder unit 160 receives the system multiplexed stream where the bitstream is demultiplexed into its respective elementary streams the video elementary stream is passed to a decoding buffer 170 and complexity parameters are passed to a scheduler and complexity estimator unit 180 from the decoding buffer 170 the video elementary stream is passed to a decoder unit 190 the decoder 190 waits for the commands coming from the scheduler unit 180 before decoding the complexity estimator 180 gives the amount of decoder computational graceful degradation that is to be employed computational graceful degradation is achieved in the decoder by decoding only a sub region of the complete picture that is deemed to contain the more important information the encoder will have to prevent the encoder and decoder from drifting apart under these conditions after decoding the decoder unit 190 also feedback information to the scheduler and complexity estimator 180 so that the information may be used to estimate the complexity of the next picture the following is the embodiment of the various units illustrated in the above invention shown in fig1 fig2 is a block.