On the relative importance of audio and video in the presence of packet losses

In streaming applications, unequal protection of audio and video tracks may be necessary to maintain the optimal perceived overall quality. For this purpose, the application should be aware of the relative importance of audio and video in an audiovisual sequence. In this paper, we propose a subjective test arrangement for finding the optimal trade-off between subjective audio and video qualities in situations when it is not possible to have perfect quality for both modalities concurrently. Our results show that content poses a significant impact on the preferred compromise between audio and video quality, but also that the currently used classification criteria for content are not sufficient to predict the users' preference.