Content dependency of the traffic control in the darwin streaming server

Abstract

The Darwin Streaming Server employs stream thinning and transmission rate adaptation for traffic and congestion control. We investigate the relation of video content with the stream thinning and transmission rate adaptation process under 3GPP-adaptation. We observe that stream thinning is not only initiated upon fluctuation of network properties or the jitter buffer, but sometimes also upon the content of the streamed video. Moreover, we show that in extreme situations the video transmission is halted based merely on content dependent properties reflected in the RTSP feedback. This may have adverse consequences for the user experience. We put forward alterations to the 3GPP-adaptation traffic control of the Darwin Streaming Server that controls the stream thinning process. The alterations aim to avoid video freezes as a result of video content dependent properties. The results show that the probability of an interrupt-free playback is higher for the alterations than for the default streaming server algorithms.