Browsing by Author "Nerode, Anil"

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    Performance Evaluation of Media Losses in the Continuous Media Toolkit
    (1997) Wijesekera, Duminda; Parikh, Shwetal; Varadarajan, Srivatsan; Srivastava, Jaideep; Nerode, Anil
    Rapid growth of multimedia systems, and accordingly research in this area requires fast prototyping environments. The Berkeley Continuous Media Toolkit (GMT} is a popular environment that satisfies this need. Form a human user's perspective, in order for multimedia demonstrations to be comprehensible, the number of audio or video frames dropped and the timing delays in the ones that are displayed, need to be kept to a minimum. Therefore, it is important to know the frame dropping characteristics of CMT. In a series of experiments we rnonir.ored tlHi variation of thPse parameters with respect processor and network loads. It was obsprvrd that loads affen ap,gregau· frame drops at lower rates and consecutive frame drops at higher rates. Because at a higher rates a liarge number of consecutive frames are dropped, the ones that are played appear in a more timely manner. As a solution to observed problems, we present some QoS based approaches to control drop and delay parameters.
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    Performance Evaluation of Synchronization Losses in the Continuous Media Toolkit
    (1997) Wijesekera, Duminda; Parikh, Shwetal; Varadarajan, Srivatsan; Srivastava, Jaideep; Nerode, Anil; Foresti, Mark
    This paper presents a performance analysis of synchronization services provided by the Berkeley Continuous Media Toolkit (CMT). The quality of audio-video synchronization is measured against processor and network loads for both remote and local clients. The metrics of analysis are the perceptible and tolerable human perceptual limits reported by Steinmetz, and another metric designed to measure synchronization of lossy media streams. It is shown that according to Steinmetz' metric CMT provides imperceptible audio-video mis-synchronization for about 10 seconds, and tolerable synchronization for about 13 seconds from the start of the clips for local clients under low processor loads. It is also shown that under high loads, synchronization is achieved at the cost of losing media frames.
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    Providing Cost-Effective Multimedia Services in a Concurrent Engineering Environment
    (1997) Wijesekera, Duminda; Parikh, Shwetal; Varadarajan, Srivatsan; Srivastava, Jaideep; Nerode, Anil
    Handling of multimedia information in a concurrent engineering environment requires that it be delivm·ed in a cost effective manner, yet having high consumc~r satisfaction. Since most such products run on general purpose computers connected by off the shelf networks, multimedia streams are likely to encounter frame losses, delays and mis-synchronizations, resulting in poor quality. This paper presents metrics to measure such qualitative degradations and reports the results of a user study to validate them. Furthermore, this paper includes the results of a performance analysis of the Continuous Media Toolkit (GMT) for constructing multimedia demonstrations, to measure its ability to satisfy parameters obtained in the user survey. In addition, we describe some enhancements that are being made to CMT to ensure user needs are met.