A Collaborative Transcoding Strategy for Live Broadcasting Over Peer-to-Peer IPTV Networks Real-time video transcoding that is often needed for robust video broadcasting over heterogeneous networks is not supported in most existing devices. To address this problem, we propose a collaborative strategy that leverages the peering architecture of peer-to-peer Internet protocol television networks and makes the computational resources of peers sharable. The video transcoding task is distributed among the peers and completed collaboratively. A prototype of the live video broadcasting system is evaluated over a 100-node testbed on the PlanetLab. The experimental results show that the proposed strategy works effectively even when the majority of the peers have limited computational resource and bandwidth.