Quality comparison of preventive control schemes for media synchronization in voice and video communications

This paper assesses the media synchronization quality of preventive control schemes employed at media sources and media destinations for voice and video over a network. Preventive control is required to try to avoid asynchrony (i.e., out of synchronization). We here deal with two preventive control techniques employed at sources: Advancement of transmission timing of media units (MUs), each of which is the information unit for media synchronization (e.g., a video picture), with network delay estimation and temporal resolution control of video. We also handle three preventive control techniques employed at destinations: Change of buffering time with network delay estimation, preventive pausing, and preventive shortening of output duration. By experiment, we make a performance comparison among preventive control schemes which employ the preventive control techniques at sources and destinations. We also clarify the relations between subjective and objective assessment results.