Perhaps you already read the post about our newly added associate Sergo Martirosov; together we were experimenting with omnidirectional, i.e. 360° video and how different bit rate, frame rate and resolution changes affect user QoE. The experiment was conducted among 20 test subjects, chosen from the student population of our Faculty.
We have selected four 360° videos for the experiment. In each test session, test subject watched all four videos but the first video which was always the same and without any quality degradations. The purpose of the first video was to relax the subjects and to allow them to immerse themselves into the VR environment. In the other three videos, different quality degradations were inserted and the objective was to see if the subjects will notice them and, if so, how the degradations will affect their perception of video quality.
We experimented with different degradations of video quality which were inserted into the original video. Namely, we introduced the resolution shifts (from 1080p to 720p, 480p and 360p), bit rate drops (from 8 Mbps to 5, 4, 3, 2 and 1 Mbps) and frame rate drops (when every other frame is lost or when 2, 3 or 4 consecutive frames are lost in transmission). We used a single stimulus method for testing, but the subjects were asked to state the rating (from 1 being poor quality to 5 being excellent quality) during the playback of the video at any time (in case they noticed the quality degradations). Hence, for each video, we collected the data about its quality during the playback (so that we can compare how the rating changes when specific quality degradation appears) as well as the overall rating of quality.
The amount of the collected data is substantial, so we are currently processing it. We’ll let you know when the results are ready for publishing.