Laboratory and Crowdsourcing Studies of Lip Sync Effect on the Audio-Video Quality Assessment for Videoconferencing Application

摘要

Lip sync is one of the factors that impacts a lot the quality of the videoconferencing experience. In this paper we study the end-user perception of the asynchrony and we try to determine the annoyance threshold of lip-synch error. We are also interested in investigating the mutual interaction between the asynchrony annoyance and changes in the video coding bit rate, spatial video resolution, video IP packet loss, and audio IP packet loss. We conducted two subjective tests in two different environments: laboratory and crowdsourcing. The experimental results show that the audio-video desynchronization annoyance is not an independent factor, but influenced by the video and audio quality. Furthermore, by comparing the results of the two tested methodologies, we show that the crowdsourcing methodology for the quality assessment might be used for audiovisual, video and asynchrony perception assessment, but there is some challenges to consider for the audio quality test.