In a network multimedia conference, a bridge service that functions as a
proxy for a client to join the conference dynamically selects a video
stream from multiple video streams originating from the other
participants of the conference and sends the selected video stream to the
client for viewing. The bridge service monitors conferencing events of
each participant and updates conferencing activity state variables of the
participant, such as whether the participant is being shown to the
client, whether the participant is talking, how long the participant has
been shown or not shown, etc. Periodically, a weight assigned to each of
the participants is computed based on the state variables, and the video
stream of the participant with the highest weight is then selected for
viewing by the client.