Evaluating the Influence of the HMD, Usability, and Fatigue in 360VR Video Quality Assessments

VR communications present great challenges that should be addressed in subjective assessment methodologies. Thus, the HMD, the usability of controllers and touchpad, or even the fatigue produced by the test session are factors that highly influence the QoE. In addition, in a 360VR scenario, most of the experiments are focused on the evaluation of video quality or the evaluation of socioemotional concepts such as the sense of presence. However, no standardized methodology to evaluate both kinds of concepts is available nowadays. In this paper, we present an experiment where video quality and sense of presence are jointly assessed in two of the most popular HMDs. As a result, we have observed that while presence is affected by the evaluation mechanism or duration of the test, quality is mainly affected by the HMD. This statement implies that methodologies that take into account technical concepts, such as encoding and transmission, and socioemotional concepts are necessary to obtain reliable and robust results of QoE in a VR environment.