This paper aims to reduce the prebuffering requirements, while maintaining continuity, for video streaming. Current approaches do this by making use of adaptive media playout (AMP) to reduce the playout rate. However, this introduces playout distortion to the viewers and increases the viewing latency. We approach this by proposing a frame rate optimization framework that adjusts both the encoder frame generation rate and the decoder playout frame rate. Firstly, we model this problem as the joint adjustment of the encoder frame generation interval and the decoder playout frame interval. This model is used with a discontinuity penalty virtual buffer to track the accumulated difference between the receiving frame interval and the playout frame interval. We then apply Lyapunov optimization to the model to systematically derive a pair of decoupled optimization policies. We show that the occupancy of the discontinuity penalty virtual buffer is correlated to the video discontinuity and that this framework produces a very low playout distortion in addition to a significant reduction in the prebuffering requirements compared to existing approaches. Secondly, we introduced a delay constraint into the framework by using a delay accumulator virtual buffer. Simulation results show that the the delay constrained framework provides a superior tradeoff between the video quality and the delay introduced compared to the existing approach. Finally, we analyzed the impact of delayed feedback between the receiver and the sender on the optimization policies. We show that the delayed feedbacks have a minimal impact on the optimization policies.
@cite_0: 
@cite_14: In this paper we present the results of a study that examines the user's perception-understood as both information assimilation and subjective satisfaction-of multimedia quality, when impacted by varying network-level parameters (delay and jitter). In addition, we integrate eye-tracking assessment to provide a more complete understanding of user perception of multimedia quality. Results show that delay and jitter significantly affect user satisfaction; variation in video eye path when either no single obvious point of focus exists or when the point of attention changes dramatically. Lastly, results showed that content variation significantly affected user satisfaction, as well as user information assimilation.
@cite_40: We study the optimal streaming of variable bit-rate (VBR) video over a random VBR channel. The goal of a streaming application is to enable the successful decoding of each video object before its displaying deadline is violated. Hence, we define the main performance metric of a streaming system as the probability of un-interrupted video presentation, or jitter-free probability. Previous literature has described solutions to estimate the jitter-free probability by assuming either independence in the encoded data process or simplistic channel models. In this work, we present a novel analytical framework, which requires only some basic statistical information of an arbitrary VBR channel, to bound the probability of jitter-free playout under the constraint of initial playout delay and receiver buffer size. Both the infinite and finite buffer cases are considered. This technique is then applied to investigate streaming over a wireless system modeled by an extended Gilbert channel with ARQ transmission control. Experimental results with MPEG-4 VBR encoded video demonstrates that the proposed analysis derives close bounds to the actual system performance. Finally, we show that the proposed analysis provides a theoretical foundation to quantify the tradeoffs between the initial playout delay, the receiver buffer size, and the jitter-free probability for a general class of VBR streaming over random VBR channels.
@cite_16: A critical component in the delivery of VBR streaming video over packet-based networks, is the playout buffer at the receiver side. As packets will incur a variable delay within the network, a mechanism is needed to dejitter the stream and assure that packets are played out at exactly the same rate at which they were generated by the sender.
Prebuffering video data has been studied in @cite_0 @cite_16 @cite_40 . These techniques are focused on calculating the correct amount of prebuffered data based on a mathematical model to avoid the occurrence of a buffer underflow once the video playout has started. However, these techniques do not take into account of the varying playout rates and the resulting reduction in prebuffering into their models. Furthermore, prebuffering introduces unwanted delay into the system and is known to have an impact on the user perceived quality of the video @cite_14 .