Unmanned Aerial Vehicles (UAVs), such as tethered drones, become increasingly popular for video acquisition, within video surveillance or remote, scientific measurement contexts. However, UAV recordings often present an unstable, variable viewpoint that is detrimental to the automatic exploitation of their content. This is often countered by one amongst two strategies, video registration and video stabilization, which are usually affected by distinct issues, namely jitter and drifting. This paper proposes a hybrid solution between both techniques that produces a jitter-free registration. A lightweight implementation enables real time, automatic generation of videos with a constant viewpoint from unstable video sequences acquired with stationary UAVs. Performance evaluation is carried out using video recordings from traffic surveillance scenes up to 15 minutes long, including multiple mobile objects.