In this paper, we propose a tree construction method to collect and composite distributed videos on the live broad-casting system called “same world broadcasting system”. The same world broadcasting system generates and delivers a video in which video objects captured at the different places are displayed as if they were located in the same world. Our tree construction method employs an “occlusion graph” that represents the overlap relations of the video objects to give a heuristic solution to find a tree of network structure to collect and composite videos which provides a high-quality video in heterogeneous environments. We implemented the tree construction algorithm and conducted computer simulations considering different scenarios. Our simulation results show that our proposal can find a good collection tree within a practical amount of time.

Recently, live video broadcasting is frequently used due to the COVID-19 pandemic. More realistic and comfortable experiments can be realized if multiple real-time videos from different places are displayed on a single screen. This paper calls such live broadcasting "same world broadcasting" as if all objects exist in the same space. In this paper, we propose a distributed system for the same world broadcasting. We evaluate the proposed system using the experimental implementation in a LAN environment and an open testbed environment. The experiment results show that the proposed system can reduce the processing time to collect and compose many real-time videos.