System and method for providing virtual pan-tilt-zoom, PTZ, video functionality to a plurality of users over a data network

A system for providing virtual pan-tilt-zoom, PTZ, video functionality to a plurality of users over a data network, the system comprising:

• one or more network video cameras positioned to make a video recording of a real-world target field, or a respective subarea thereof, and output a respective raw video segment onto the data network;
• a back-end camera calibration unit which is adapted to obtain a relative position and orientation of the respective network video camera with respect to a three dimensional world space for the target field, and to save the obtained relative position and orientation as metadata for the respective network video camera;
• a back-end video processing unit, connected to the data network and adapted to receive the respective raw video segment(s) recorded by the network video camera(s), and to store or buffer video contents of the respective raw video segment(s) in a back-end video storage;
• a back-end video streaming unit adapted to stream the stored or buffered video contents and the saved metadata for the respective network video camera onto the data network;
• and
• a plurality of client devices for use by the plurality of users, wherein each client device is adapted to:
• receive the streamed video contents and the metadata;
• determine a chosen virtual pan-tilt-zoom value;
• and
• present, on a display of the client device, the video contents by projecting directions, in the three dimensional world space, onto the display based on the chosen virtual pan-tilt-zoom value and the metadata, wherein the virtual pan-tilt-zoom value defines a projection plane of a virtual camera, and wherein a display screen coordinate of a direction in space is determined by where it intersects the projection plane.