MPEG-21is an open standards-based framework for multimedia delivery and consumption. It aims to enable the use of multimedia resources across a wide range of networks and devices. We discuss MPEG-21's parts, achievements, ongoing activities, and opportunities for new technologies. Disciplines Physical Sciences and MathematicsPublication Details

The previous decade has seen a variety of trends and developments in the area of communications and thus multimedia access. While individual, isolated developments produced small advances on the status quo, their combination and cross-fertilization resulted in today's complex but exciting landscape. In particular, we are beginning to see delivery of all types of data for all types of users in all types of conditions. This article discusses the current status of universal multimedia access (UMA) technologies and investigates future directions in this area. Key developments and trends from the last few years have set the scene for ubiquitous multimedia consumption. In summary, these are: wireless communications and mobility; standardized multimedia content; interactive versus passive consumption; and the Internet and the World Wide Web (WWW). Disciplines Physical Sciences and MathematicsPublication Details

Spatially squeezed surround audio coding (S3AC) has been previously shown to provide efficient coding with perceptually accurate soundfield reconstruction when applied to ITU 5.1 multichannel audio. This paper investigates the application of S3AC to the coding of Ambisonic audio recordings. Traditional ambisonics achieve compression and backward compatibility through the use of the UHJ matrixing approach to obtain a stereo signal. In this paper the relationship to Ambisonic B-format signals is described and alternative approaches that derive a stereo or mono-downmix signal based on S3AC are presented and evaluated. The mono-downmix approach utilizes side information consisting of spatial cues that are quantized based on novel source localization listening experiments. Objective and subjective tests demonstrate significant improvements in the localization of sound sources resulting from decoding the compressed B-format signals to a 5.1 speaker playback. A SPATIAL SQUEEZING APPROACH TO AMBISONIC AUDIO COMPRESSION Bin Cheng, Christian Ritz and Ian BurnettWhisper Laboratories, University of Wollongong, Wollongong, NSW, Australia bc362@uow.edu.au, critz@uow.edu.au, ianb@uow.edu.au ABSTRACTSpatially Squeezed Surround Audio Coding (S 3 AC) has been previously shown to provide efficient coding with perceptually accurate soundfield reconstruction when applied to ITU 5.1 multichannel audio. This paper investigates the application of S 3 AC to the coding of Ambisonic audio recordings. Traditional Ambisonics achieve compression and backward compatibility through the use of the UHJ matrixing approach to obtain a stereo signal. In this paper the relationship to Ambisonic B-format signals is described and alternative approaches that derive a stereo or mono-downmix signal based on S 3 AC are presented and evaluated. The mono-downmix approach utilizes side information consisting of spatial cues that are quantized based on novel source localization listening experiments. Objective and subjective tests demonstrate significant improvements in the localization of sound sources resulting from decoding the compressed B-format signals to a 5.1 speaker playback.

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Multimedia is ubiquitously available online with large amounts of video increasingly consumed through Web sites such as YouTube or Google Video. However, online multimedia typically limits users to visual/auditory stimulus, with onscreen visual media accompanied by audio. The recent introduction of MPEG-V proposed multi-sensory user experiences in multimedia environments, such as enriching video content with so-called sensory effects like wind, vibration, light, etc. In MPEG-V, these sensory effects are represented as Sensory Effect Metadata (SEM), which is additionally associated to the multimedia content. This paper presents three user studies that utilize the sensory effects framework of MPEG-V, investigating the emotional response of users and enhancement of Quality of Experience (QoE) of Web video sequences from a range of genres with and without sensory effects. In particular, the user studies were conducted in Austria and Australia to investigate whether geography and cultural differences affect users' elicited emotional responses and QoE.