Software-Based Video–Audio Production Mixer via an IP Network

Modern television production has promoted the simultaneous use of several cameras and sound sources, which increases the complexity and costs of broadcasting studios. This paper describes the design and implementation of a video-audio production mixer via an IP network. It is presented as a potential replacement for traditional professional production systems on the basis of cost reduction, as it is a software-based system that uses the existing technologies and can be built in community television stations and economic private productions. A prototype combining five cameras, a title generator, a multimedia player, microphone sound, music, and other resources for video recording or Internet live streaming has been implemented. The system also features a voice intercommunication capability to support teamwork. This technology has been mounted using different high-definition cameras with High-Definition Multimedia Interface (HDMI) outputs, desktop computers, mobile phones and other non-dedicated equipment available for free or at a low cost. Although it works on non-dedicated hardware, this system provides video routing, sound managing, and audiovisual mixing with an approximate total delay of only 1.4 s. It has been mounted mostly on Linux environments to guarantee reliability and the extensive use of free software, which demonstrates the feasibility of building a cost-effective video-audio production mixer, using the available devices and techniques.