In this paper, a flexible middleware system for omni-directional video transmission for various teleconferencing applications is introduced. The omni-directional image has more advantages in that it provides a wider view than a single directional camera and able to realize flexible TV conferencing even between remotely separated small rooms. In this paper, we describe system architecture and functions of the middleware for high-definition omni-directional image control and effective video transmission system using DV and HDV (1080i format)[4]. The MidField system which we have developed so far is used for video stream transmission over IPv4/IPv6 networks. The prototype system of a TV conference is constructed to evaluate our suggested high-definition omni-directional middleware. Through the functional and performance evaluation of the prototyped system, we could verify the usefulness of our proposed system.