A System for Distributed Multi-camera Capture and Processing

This contribution describes a distributed multi-camera capture and processing system for real-time media production applications. Its main design purpose is to allow prototyping of distributed processing algorithms for free-viewpoint applications, but the concept can be adapted to other (multicamera) applications. The system integrates broadcast components into a distributed IT-based processing system. The problems that are addressed in this contribution are the synchronisation of these sub-systems and the data and control flow. For the synchronisation of the broadcast and IT components we developed a time stamp mechanism based on tightly synchronised PC clocks. This time is used as the master clock of the system. The video frames from the gen-locked multi-camera streams are implicitly synchronised by adjusting their relative timing against this system clock. For the purpose of synchronising the PC clocks two protocols (NTP and PTP) were evaluated. The second main contribution is the processing of multi-camera data in the distributed system. For this purpose a software framework was developed based on a distributed concurrency system implemented in Python.