Dynamic video playout smoothing method for multimedia applications

Multimedia applications including video data require the smoothing of video playout to prevent potential playout discontinuity. In this paper, we propose a dynamic video playout smoothing method, called the video smoother, which dynamically adopts various playout rates in an attempt to compensate for high delay variance of networks. Specifically, if the number of frames in the buffer exceeds a given threshold (TH), the smoother employs a maximum playout rate. Otherwise, the smoother uses proportionally reduced rates in an effort to eliminate playout pauses resulting from the emptiness of the playout buffer. To determine THs under various loads, we present an analytic model assuming the Poisson process arrival correspondent with a network with a traffic shaper. Based on the analytic results, we establish a paradigm of determining THs and playout rates for achieving different playout qualities under various loads of networks. Finally, to demonstrate the viability of the video smoother, we have implemented a prototyping system including a multimedia teleconferencing application and the video smoother performing as a part of the transport layer. The prototyping results show that the video smoother achieves smooth playout incurring only unnoticeable delays.