Prerequisites

Owned by alon.men@zixi.com
21 Apr 2021
2 min read

This tutorial assumes that you have installed and activated two Zixi Broadcasters (a sending Zixi Broadcaster and a receiving Zixi Broadcaster) and that it they are connected to the internet. For an explanation of how to install and activate a Zixi Broadcaster see Zixi v14 Installation Guide.

You will also need to have an active NDI stream available on your LAN. In the sending side, you will need to install the mDNS (Bonjour / Zeroconf) discovery mechanism, which advertises sources on a local area network.

Hardware Requirements

Transcoding is required on both the sending and receiving side. The Zixi Broadcaster can make use of the following transcoding configurations:

  • X264 software for AVC/H.264 encode/decode

  • NVIDIA GPU for AVC/H.264 and HEVC/H.265 encode/decode.

NVIDIA GPUs are available on AWS, GCP, and Azure, and for bare-metal installations they are available in the NVIDIA Quadra P2XXX and RTX XXXX family of PCIe cards. Zixi has a partnership with ScaleLogic to provide servers that include these NVIDIA cards but these cards and servers can be sourced from other sources as well.

Software Requirements

NDI utilizes mDNS (multicast Domain Name System) to create a zero configuration environment for discovery of NDI streams available on the LAN. Through mDNS, devices such as the Zixi Broadcaster can discover available NDI streams for processing.

The use of mDNS requires operating system support as follows:

  • Windows - Windows 10 has mDNS support built in, which is necessary for any NDI applications running on Windows.

  • CentOS - The recommended platform for the Zixi Broadcaster is CentOS 7. mDNS support is provided by the Avahi package which typically is not installed by default on CentOS 7.

To install Avahi, run the following commands on the server hosting the Zixi Broadcaster:

# sudo yum install avahi # sudo service avahi-daemon start

Network

The mDNS Ethernet frame is a multicast UDP packet that broadcasts to:

  • MAC address 01:00:5E:00:00:FB(for IPv4)

  • IPv4 address 224.0.0.251

  • UDP port 5353

You need to verify that the LAN where NDI streams are present is multicast enabled and that all systems needing access to NDI streams, such as the Zixi Broadcaster, do not block mDNS via their firewall.