NDI is the dominant IP-based studio video transport. It encodes video with a lightweight intra-frame codec (NDI SpeedHQ, or NDI HX2/HX3 for compressed variants), runs over normal LAN at 100–300 Mbps per stream, supports audio, alpha, tally and PTZ control in-band, and discovers sources automatically over mDNS. It was launched by NewTek in 2015 and is now widely supported by switchers (vMix, OBS, Wirecast), cameras (BirdDog, PTZOptics), software (Streamlabs, Zoom NDI mode) and broadcast playout systems.
Inside a studio NDI replaces SDI cables. Where SDI runs one direction over coax with no return signal and no audio mixing, NDI runs bidirectionally over Ethernet, automatically reroutes through Layer-2 switches, and brings tally/PTZ along the same wire. A small studio with ten NDI cameras can be wired with a single managed Ethernet switch and zero SDI infrastructure — a massive cost and complexity win.
NDI is not a contribution-to-cloud protocol — its bitrate is too high for public internet and it relies on local network properties (multicast, low jitter, mDNS) that the internet does not provide. For going from a NDI-based studio out to a cloud encoder or live platform, the pattern is NDI→SRT or NDI→WHIP via a gateway product (vMix, OBS, BirdDog Cloud, Sienna). NDI 5 (2021) added bridging over SRT for site-to-site use, narrowing the boundary, but cloud contribution remains SRT/WHIP territory in 2026.
