QoE assessment of multimedia video consumption on tablet devices

In this paper we present a study aimed at assessing the Quality of Experience in video streaming when the user is employing a tablet devices. The study has been conducted on a database containing subjective assessment scores relative to 216 streaming sessions of video sequences encoded with H.264/AVC and corrupted by typical wireless channel transmission errors. Four 20sec-long video sequences at Common Intermediate Format (CIF) spatial resolution have been corrupted with 54 combinations of key parameters for the reference application: bitrate, packet loss rate, playout delay and transmission interruption. Subjective evaluations have been collected in compliance with ITU-T Recommendation P.910 through singlestimulus Absolute Category Rating (ACR) from 40 subjects. The videos were reproduced on two different tablet devices: on an Apple iPad 2 and on a Samsung Galaxy Tab GT-P1000. Subjective observations include the perceived quality considering all aspects of the fruition chain, from the coding to the environment and device specific issues. The evaluation results also provided several remarks that can be helpful in designing systems and applications for multimedia contents played back on tablets. The results show a good correlation between subjective observations and some impairments so that a simple QoE index is proposed. A correlation study between subjective assessment and objective metrics is also provided.