NDI — Network Device Interface
Definition
NDI (Network Device Interface) is a video-over-IP protocol created by NewTek, now developed by the Vizrt group, which acquired NewTek in 2019. It carries video, audio and metadata over standard Ethernet networks and lets devices discover the sources available on the network. NDI High Bandwidth uses the SpeedHQ codec, an intra-frame compression described as visually lossless; a 1080p60 stream needs at most about 132 Mbit/s, compared with 2.97 Gbit/s for the same format uncompressed in 3G-SDI. NDI HX3 uses H.264 or H.265 compression and needs up to about 62 Mbit/s in H.264 at 1080p60. Latency is in the order of one frame in High Bandwidth. NDI requires gigabit Ethernet ports at a minimum, and 10 GbE is recommended for systems with many streams or 4K sources.
In the field
NDI and Dante traffic on the same network compete for bandwidth and switch resources. The usual practice is to separate them on different VLANs or dedicated switches and to apply quality of service; the NDI documentation publishes recommended switch settings. A gigabit uplink shared by several High Bandwidth streams and a Dante network can saturate, which produces video drops and audio clicks.
Related lessons
Sources
- NDI Docs, White paper Bandwidth, NDI High Bandwidth (SpeedHQ2, 8 bits 4:2:2) : 132,14 Mbit/s au maximum en 1080p60 · docs.ndi.video
- NDI Docs, White paper Bandwidth, NDI HX3 H.264 (8 bits 4:2:0) : 62 Mbit/s au maximum en 1080p60 · docs.ndi.video
- NDI Docs, Recommended Network Switch Settings for NDI : ports gigabit au minimum, réglages de switch · docs.ndi.video
- Sports Video Group, Vizrt Purchases NewTek (1er avril 2019) : rachat de NewTek par Vizrt en 2019 · sportsvideo.org
- Wikipédia, Serial digital interface : SMPTE ST 424, 3G-SDI à 2,97 Gbit/s (débit non compressé de référence en 1080p60) · en.wikipedia.org