Mixed adaptation and fixed-reservation QoS for improving picture quality and resource usage of multimedia (NoC) chips

Advanced video systems running multiple applications require an efficient distribution of system resources. An adaptable computing system can be created with a reconfigurable network-on-chip (NoC). Execution of multiple multimedia processing tasks implicitly ask for a reservation-based Quality-of-Service (QoS) control. However, pure reservation-based systems have rigid rules for assigning resource budgets, leading to a slow reaction time on activity change or a long reconfiguration time. In this paper, we present an application-specific QoS solution that combines a reservation-based approach with a run-time adaptation facility. We demonstrate this framework by mapping an MPEG-4 arbitrary-shaped video decoder on an NoC of eight ARM cores with specific monitoring features in the network (e.g. Ethereal NoC). First, we have found that our advanced QoS can save up to 32% of communication resources. Second, we have obtained experimental results showing the absolute PSNR of approximately 35 dB with a quality improvement of 1-5 dB, using the "Stefan" tennis sequence, as compared to the implementation with reservation-based approach only