Implementation of a media synchronization algorithm for multistandard IP set-top box systems

Media synchronization at network context minimizes the effects of the network jitter and the skew between the emitter and receiver clocks. Theoretical algorithms cannot always be implemented on real systems for the architecture differences between a real and a theoretical system. In this paper an implementation for an intra-medium and an inter-media synchronization algorithm for a real multistandard IP set-top box is presented. For intra-medium synchronization, the proposed technique is based on controlling the receiver buffer. However for inter-media synchronization, the proposed technique is based on controlling the video playback according the Presentation Time Stamp (PTS) of the media units (audio and video). The proposed synchronizations algorithms has been integrated in an IP-STB and tested in a real environment using DVD movies and TV channels with excellent results. Those results show that the proposed algorithm can achieve media synchronization and meet the requirements of perceived quality of service (P-QoS).