Abstract: A technique wherein the number and position of a quantization parameter node is determined in response to the quantization parameters and a preselected error. The size of scene graph and the corresponding amount of memory required to store the scene graph can be reduced by selective placement of quantization parameter nodes in a scene graph. The scene graph is traversed depth first to establish an order and then traversed in reverse. At each node, a calculation relating to (1) the relative cost of inserting a quantization parameter node and (2) the relative savings that result from insertion of a quantization node is performed. Quantization parameter nodes are selectively placed in response to a result of these calculations. The maximum degree of acceptable error value is chosen for each quantization type. This error value limits the number of quantization parameter nodes that can be placed in a scene graph.

Abstract: A technique wherein a data stream received by a viewer is responsive to input from other viewers. The data stream is sent from a server to a set of users who generate various responses to the media stream. The responses are analyzed and the analysis or other appropriate response is back to the users. In this way, the information displayed by a user is modified by how other users interact with the media stream. Additionally, the response of a particular user to a data stream may result in personalized information being sent to that user in real time. Various configurations are used to multicast or unicast a program to users and multicast or unicast additional information that is responsive to input from those users.