Experiments in MPEG4 content authoring, browsing and streaming In this paper, within the context of the MPEG4 standard we report on preliminary experiments in three areas authoring of MPEG4 content, a playerbrowser for MPEG4 content, and streaming of MPEG4 content. MPEG4 is a new standard for coding of audiovisual objects; the core of MPEG4 standard is complete while amendments are in various stages of completion. MPEG4 addresses compression of audio and visual objects, their integration by scene description, and interactivity of users with such objects. MPEG4 scene description is based on VRML like language for 3D scenes, extended to 2D scenes, and supports integration of 2D and 3D scenes. This scene description language is called BIFS. First, we introduce the basic concepts behind BIFS and then show with an example, textual authoring of different components needed to describe an audiovisual scene in BIFS; the textual BIFS is then saved as compressed binary files for storage or transmission. Then, we discuss a high level design of an MPEG4 playerbrowser that uses the main components from authoring such as encoded BIFS stream, media files it refers to, and multiplexed object descriptor stream to play an MPEG4 scene. We also discuss our extensions to such a playerbrowser. Finally, we present our work in streaming of MPEG4  the payload format, modification to client MPEG4 playerbrowser, serverside infrastructure and example content used in our MPEG4 streaming experiments.

On Media Data Structures for Interactive Streaming in Immersive Applications Interactive media streaming is the communication paradigm where an observer periodically requests new desired subsets from the streaming sender in realtime, upon which the sender sends the appropriate media data, corresponding to the received requests, for immediate decoding and display. This is in contrast to noninteractive media streaming, e.g., TV broadcast, where the entire media set is compressed and delivered to the observer before the observer interacts with the data (such as switching TV channels). Examples of interactive streaming abound in different media modalities: interactive browsing of JPEG2000 images, interactive light field or multiview video streaming, etc. Interactive media streaming has the obvious advantage of bandwidth efficiency: only the media subsets corresponding to observeru0027s requests are transmitted. This is important when an observer only views a small subset out of a very large media data set during a typical streaming session. The technical challenge is how to structure media data such that good compression efficiency can be achieved by exploiting correlation among media subsets (thus inducing a particular decoding order if correlation is exploited during encoding), while providing sufficient flexibility for the observer to freely navigate the media data set in hisher desired unique order. In this overview paper, we survey different proposals in the literature that simultaneously achieve the conflicting objectives of compression efficiency and decoding flexibility.