José C. López-Ardao

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In this paper, a simple mathematical formula is proposed which provides estimation for the perceived video quality, based solely in the codec used, the display format, the bit rate and the movement content in the original video. The quality metric used is one of the recently standardized in Recommendations ITU-T J.144 and ITU-R BT.1683, and developed by(More)
Several recent traffic measurement studies have convincingly shown the presence of self-similarity in modern high-speed networks, involving a very important revolution in the stochastic modeling of traffic. Thus the use of self-similar processes has opened new problems and research fields in network performance analysis, mainly in simulation studies, where(More)
In last decade, we have seen the first steps to the end of passive television. Thanks to continuous advances in hardware and software, now, Digital TV technology is mature enough to enhance traditional TV sets (limited to content reproduction) with computing capability to run multimedia software integrating richer formats. And a significant example of this(More)
In this paper we analyze how the frame rate affects the video perceived quality for different video contents. Combining these results with our previous work, a new parametric model is proposed for video quality estimation, including the effects of frame rates, bit rate, display size and video content. The performance of the new proposed model was evaluated(More)
In this paper, we show how the proposed model in ITU-T Recommendation G.1070 "Opinion model for video-telephony applications" cannot model properly the perceptual video quality, especially in the low bit rate range, due to the great variation of MOS values depending on video content. In this work, we present different enhancements to the model, allowing a(More)
Mean value estimation of processes exhibiting Long Range Dependence (LRD) requires a different approach than the techniques applied to those exhibiting Short Range Dependence (SRD), except for the independent replication method. We describe a nonoverlapping batch means method able to deal with LRD processes, the LRD Batch Means method. This method exploits(More)