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This paper studies the quality of multimedia content focusing on 360 video and ambisonic spatial audio reproduced using a head-mounted display and a multichannel loudspeaker setup. Encoding parameters following basic video quality test conditions for 360 videos were selected and a low-bitrate codec was used for the audio encoder. Three subjective experiments were performed for the audio, video, and audiovisual respectively. Peak signal-to-noise ratio (PSNR) and its variants for 360 videos were computed to obtain objective quality metrics and subsequently correlated with the subjective video scores. This study shows that a Cross-Format SPSNR-NN has a slightly higher linear and monotonic correlation over all video sequences. Based on the audiovisual model, a power model shows a highest correlation between test data and predicted scores. We concluded that to enable the development of superior predictive model, a high quality, critical, synchronized audiovisual database is required. Furthermore, comprehensive assessor training may be beneficial prior to the testing to improve the assessors' discrimination ability particularly with respect to multichannel audio reproduction.In order to further improve the performance of audiovisual quality models for immersive content, in addition to developing broader and critical audiovisual databases, the subjective testing methodology needs to be evolved to provide greater resolution and robustness.

The use of daylight offers a positive contribution to building energy savings yet also provoke a shortfall anticipation such as the large amount of light and visual discomfort. Moreover, building energy demand will also depend on the lighting control system combined with occupants' behaviour of which is still rarely studied. This paper addressed the evaluation of climate-based daylight performance in a simulated reference office with a single unglazed opening measuring various window-to-wall ratio on one of the short façades facing different orientations. Modelling and simulation were performed in Radiance and Daysim using weather data of Yogyakarta and Bandung, Indonesia. Six different lighting control conditions were included. The following metrics observed are: average daylight factor, spatial daylight autonomy, spatial useful daylight illuminance, simplified daylight glare probability and lighting energy demand due to the lighting control system. Sensitivity analysis using multiple linear regression was also included. Excluding the average daylight factor, the results yielded similar trends for each metrics in two cities. However, the trend of sDA and sUDI-e in Yogyakarta are getting higher than Bandung in contrast with lighting energy demand. Moreover, combination switch-off occupancy & dimming system shows the most efficient lighting control system in all conditions.

For accurate and detailed perceptual evaluation of compressed omnidirectional multimedia content, it is imperative for assessor panels to be qualified to obtain consistent and high-quality data. This work extends existing procedures for assessor selection in terms of scope (360 • videos with high-order ambisonic), time efficiency, and analytical approach, as described in detail. The main selection procedures consisted of a basic audiovisual screening and three successive discrimination experiments for audio (listening), video (viewing), and audiovisual using a triangle test. Additionally, four factors influencing quality of experience, including the simulator sickness questionnaire, were evaluated and are discussed. After the selection process, a confirmatory study was conducted using three experiments (audio, video, and audiovisual) and based on a rating scale methodology to compare performance between rejected and selected assessors. The studies showed that (i) perceptual discriminations are influenced by the samples, the encoding parameters, and some quality of experience factors; (ii) the probability of symptom occurrence is considerably low, indicating that the proposed procedure is feasible; and (iii) the selected assessors performed better in discrimination than the rejected assessors, indicating the effectiveness of the proposed procedure.

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