An Environment for Test and Evaluation of Synchronism for Digital Video Transmission

Abstract

Content distribution packet networks can be used in video and audio transport for TV applications. These networks make signal transport more flexible. Nevertheless, they may add delay and jitter, damaging the synchronism of the information streams and, consequently, the media presentation. In this paper, an environment was proposed for synchronism test and evaluation. It was developed to study the influence of disturbances caused by data networks in the synchronism of MPEG2 programs. It enables the control of QoS parameters of the distribution network used to transmit packets from a MPEG2 transport stream and allows the evaluation of the influence of these parameters in the synchronism of the streams. Furthermore, transport stream resynchronization mechanisms were implemented, minimizing the effects of these disturbances in the network. It was observed that the methods implemented reduce the effects of jitter in the network and resynchronize the transport stream transmitted, in a way that the jitter in the time reference samples (Program Clock Reference -PCR) of the stream returns to previous levels (without applying jitter in the network).