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title: Network Device Interface (NDI)
breadcrumbs:
- title: Media
---
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A network video protocol by NewTek.

## Info

- A royalty-free protocol by NewTek for sharing video over IP in a standard Gigabit LAN (or better).
- Provides multiple high-quality, low-latency and frame-accurate video and audio feeds.
- Uses mDNS by default for autodiscovery. Alternatively, one or more discovery servers may be used.
- Supports multicast sending, but it's disabled by default.

### Encoding

- The normal, high-bandwidth encoder is simply called "NDI".
- NDI provides multi-generational stability, meaning repeated encodings don't degrade quality.
- Has a technical latency of 16 video scan lines, although typically lower in implementations.
- "NDI\|HX", meaning "NDI High Efficiency", uses much lower bitrate and is appropriate when bandwidth is limited.

### Transport Protocols

- Reliable UDP: Supports very high-latency networks. Has built-in  congestion control and loss recovery and no head-of-line blocking.
- Multipath TCP: Uses multiple NICS and multiple network paths.
- Single TCP: Nothing special.
- UDP with FEC: For when reliable delivery is not required. Has forward error correction (FEC).

### Recommendations

- The network must be high-bandwidth, low-latency, jitter-free and highly available.
- The network should be mostly dedicated to NDI streams.
- The network topology should be designed with requirements in mind.
- Gigabit, consumer off-the-shelf (COTS) equipment is generally good enough.
- While NDI supports using multiple NICs and may automatically distribute streams to different NICs, NIC teaming/aggregation is often preferred if possible.
- The network should be optimized for multicast traffic with IGMP if multicast sending is enabled.
- Maximum throughputs for streams:
    - NDI 1920x1080 60Hz: 132Mb/s
    - NDI 1920x1080 60Hz (with alpha): 165Mb/s
    - NDI 3840x2160 60Hz: 249Mb/s
    - NDI 3840x2160 60Hz (with alpha): 312Mb/s
    - NDI\|HX 1920x1080 60Hz: 15.9Mb/s
    - NDI\|HX 1920x1080 60Hz (H.264 & HEVC): 10.9Mb/s
    - NDI\|HX 3840x2160 60Hz: 30.0Mb/s
    - NDI\|HX 3840x2160 60Hz (H.264 & HEVC): 21.0Mb/s

## Usage

### NDI Tools

- Contains tools for e.g. sending streams, receiving streams, sending test streams, routing streams, bridging streams etc.
- Contains plugins/extensions to VLC, Premiere Pro and After Effects.
- For Windows and Mac only.
- [Download](https://ndi.tv/tools/)

### NDI SDK

- The NDI SDK is used to develop native NDI applications.
- For targeting Apple, Android, Linux/ARM, Windows etc.
- [Download](https://ndi.tv/sdk/)

### OBS NDI Plugin

See [OBS](/media/obs/).

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