[Institut für Informatik] [Fakultät für Angewandte Wissenschaften] [Universität Freiburg]


C. Bacher, R. Müller, T. Ottmann, M. Will,
An Integrated Environment for MBone Session Recording and Replay,
Proceedings ED-MEDIA '97, Calgary, Canada, June 1997


An Integrated Environment for Mbone Session
Recording and Replay

Chr. Bacher, R. Müller, Th. Ottmann, M. Will
Institut für Informatik, Universität Freiburg
e-mail: {bacher, rmueller, ottmann, will}@informatik.uni-freiburg.de

We present an environment for the seamless production of educational hypermedia documents following a method called Authoring on the fly (AOF) [OBa95]. Authoring on the fly means to combine different tasks like giving a lecture, teleteaching and producing hypermedia documents for educational purpose. Our environment called aofShell demonstrates how to produce these documents on the fly while giving a lecture using the electronic whiteboard wb of the Mbone tools [Eri94]. aofShell integrates the recording of audio and whiteboard actions, the seamless conversion into a AOF document and the immediate replay with the built-in viewer from the personal workstation's desktop.

The production of a AOF document is described as follows: First, all the slides to be used in a specific lecture are selected. These slides are PostScript documents produced as usual by standard tools such as LaTeX or Framemaker. In order to enhance the comprehension of the lecture, any applications such as animations or movies can be included. The slides and applications can be provided with custom titles. These are later used to automatically generate a table of contents for the hypermedia document. At this stage, the recording session is ready to be started. While recording, the slides are loaded into the whiteboard. These can be marked and annotated as usual using the whiteboard's features. While delivering the lecture, the selected applications can be started simultaneously. The data resulting from these actions, namely the whiteboard data stream, the applications' start and stop commands and the audio stream, are recorded. At the end of the recording session, the data is immediately converted into an internally used format [OBa95] to generate an integrated document for offline use. Upon accessing the document, the built-in viewer performs the synchronous replay of the recorded data streams as well as starting and stopping the applications as presented during the lecture. An integrated document handler supports the creation of collections where any additional documents can be inserted. Operations for moving, copying or deleting documents are also supported.

In an alternative setting, the MBone whiteboard's multicast facilities are used, thus combining our own environment with the MBone tools vic and vat for a rcording of a teleteaching session, which is simultaneously transmitted to remote locations. We also provide a receiver in order for the remote audience to see the animations, movies or any arbitrary application running while seeing the whiteboard actions and listening to the lecturer's voice received by vat.


Th. Ottmann, Chr. Bacher: Authoring on the Fly. Journal of Universal Computer Science, Vol. 1, No. 10, October 1995
H. Eriksson: Mbone: The multicast backbone, ACM Communications, 37:54-60, 8 1994.

Submitted for EDMEDIA '97, the World Conference on Educational Multimedia and Hypermedia (June 14-19, Calgary, Canada)