Aims

- To develop a multimedia transcoding system for the PANTS active networking framework

- A protocol for communication with active nodes in the network

- PANTS applications for the control of transcoders at active nodes

- A set of sample transcoders for use in the framework

Motivation

- In the future, more and more information on local networks and the Internet at large will be delivered in multimedia form

- End-users of this multimedia content have differing requirements; some can not receive high-bandwidth content, some can not decode some media formats.

- Often recipients of multimedia streams are limited to just the “lowest common denominator” in multimedia formats — those users able to receive a more detailed stream miss out

- Active networking provides a solution to these problems that is flexible and that can co-exist with existing protocols

PANTS and Active Networking

- Active networking is a relatively new paradigm in which computation is introduced and executed at the network layer

- PANTS is a dynamically upgradable active networking framework written in Python

- PANTS applications can inject “capsules” onto the network; an active node, upon receiving a capsule, executes the code in that capsule; this code may perform some computation or choose to route the capsule to another node

- The PANTS architecture provides an ideal environment for multimedia transcoding since it is secure and can be modified easily

Multimedia Transcoding

- Transcoding involves the conversion of a multimedia stream from one format to another

- A change of encoding: MPEG ? H.263

- A change of encoding parameters: MP3 at 256kbps ? MP3 at 128kbps

- One can also duplicate a multimedia stream so that it can be multicasted

- Different streams from a common source can have different transcodings applied to them