Differentiated object priority control mechanism for MPEG-4 streaming

An MPEG-4 multimedia movie may involve hundreds of audio-video objects, which complicate object-based transmission and presentation. This study proposes a differentiated object priority control (DOPC) system for MPEG-4 streaming. The DOPC system is based on standard MPEG-4 DMIF architecture and combines object priority, layer adaptation and TFRC (TCP friendly rate control) congestion control schemes. The DOPC system achieves harmonic streaming transmission using the proposed differentiated transmission schedule strategy (DTS2). The basic control approach of DTS2 is to proportionally differentiate the bandwidth and adjust the object qualities for different media streams based on the priority assignment of media objects. When the network situation is poor, the DTS2 mechanism continues to provide a smooth presentation by effectively decreasing the transmission bandwidth of some of the lower priority media objects to achieve transmission adaptation control. The evaluation results indicate that the proposed DTS2 mechanism provide harmonic bandwidth differentiation.