Management of Brno Municipality has decided to improve the quality of live broadcasts from their meetings that can be watched on the internet. In order to that, it was necessary to modernize the existing analog camera system with a digital one. Not only that the old camera system had a small resolution, but even the sensitivity at lower levels of room illumination, in addition to that the positions of cameras were unsatisfying, because they were too high and therefore did not allow optimal view of the human faces.
For the transmission of FullHD video signal from cameras to a digital production switcher, 3G HD-SDI transmission system (SMPTE 424M standard) was selected. A coaxial metallic cable with low attenuation was chosen as the transfer medium.
Control signals are transmitted via data shielded cabling by the VISCA protocol which are send from the control panel to the cameras. The DC power is transmitted to the cameras by a two-wire power cord connected to power adapters that are located in a rack at the control room.
Former image sources are connected to converters which ensure that the original analog and digital video signals are adapted to the newly designed production switcher. The system has been expanded with a presentation option from any video source possessing VGA output signal (RGB, YPbPr) + audio, HDMI or DisplayPort.