# Using NDI® outputs in a MediaConnect flow NDI outputsNDI® outputs You can now use NDI® outputs to send content from your MediaConnect flow to your NDI environment. AWS Elemental MediaConnect can convert MPEG transport streams into [Network Device Interface (NDI®)](https://ndi.video/tech/), a protocol for high-quality, low-latency video and audio over IP networks. This capability enables direct content delivery within your network, connecting traditional contribution workflows with IP-based video production systems. Using NDI outputs, you can create streamlined production workflows that take content from your AVC or HEVC-based encoder, process it through a MediaConnect flow as a transport stream, and output it directly into your Virtual Private Cloud (VPC) as NDI. Your production systems—including vision mixers, audio mixers, replay systems, and graphics engines—can immediately access these NDI streams through standard NDI discovery. This integration works with your existing NDI infrastructure, requiring no modifications to your current VPC setup. ## Key points ### Understanding NDI terminology In video and audio workflows, the terms *source* and *output* have specific meanings that vary between contexts. Understanding these differences helps you work with NDI outputs across your production workflow. + In MediaConnect flows: + A *source* is the incoming video and audio feed to the flow. NDI is supported as a source type. + An *output* determines where and how your content is delivered. NDI is supported as an output type. + In NDI implementation: + An NDI source is a network endpoint that sends video and audio streams over IP networks using the NDI protocol. + When you add an NDI output to your MediaConnect flow, MediaConnect acts as an NDI sender by creating an NDI source. Your production systems can then connect to this source as NDI receivers to get the video and audio stream. In summary: Your MediaConnect flow takes video and audio from a flow source and, with an NDI flow output enabled, it creates an NDI source that your production systems can receive from. ### How NDI outputs work At a high level, here’s how your content moves through MediaConnect when you use NDI outputs: 1. You create a large sized flow with NDI enabled, configuring your discovery servers and NDI output settings. 1. You send content to the flow source, using supported transport stream protocols such as SRT or Zixi. 1. MediaConnect processes the content to the flow output, creating a discoverable NDI source in your VPC. 1. The production systems in your network can now discover and connect to these endpoints and receive your content. This workflow maintains compatibility with existing broadcast infrastructure while adding the flexibility and networking advantages of NDI distribution. ### White screen generation for NDI outputs When you configure a transport stream flow with NDI outputs, MediaConnect automatically generates white video frames to provide a valid source signal for downstream NDI devices. This helps you confirm that your NDI output is properly configured and functioning, even when your source isn't actively sending content. The white frame generation operates as follows: + **On initial flow startup** - If no source content is received within 10 seconds, MediaConnect generates white frames with silent audio on your NDI output. + **After a source has connected and started sending content** - If a source disconnects for more than 60 seconds, MediaConnect generates white frames with silent audio. This feature is particularly useful when you're setting up flows in advance of live events, or in situations where your source content isn't immediately available. The white frames serve as a visual indicator that your NDI output is working correctly and is ready to receive source content. This is more informative than seeing a black screen, which could either indicate a loss of signal or intentional black video content from your source. This feature is available exclusively for NDI outputs. You don't need to configure or enable white screen generation - it works automatically whenever your flow is in a running state but isn't receiving source content. When your source starts sending content to your flow, the source content automatically replaces the white frames. MediaConnect stops generating silent audio frames, and the audio passes through from the source. ### Considerations and limitations When planning your NDI output implementation in MediaConnect, keep in mind the following. [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/mediaconnect/latest/ug/outputs-using-ndi.html) ### Supported decoding parameters The following table outlines the supported decoding parameters for NDI outputs in MediaConnect. For video decoder parameters: the supported bit depth/codecs for AVC should be the same as HEVC. | Decoding parameter | Description | | --- | --- | | Video codec and chroma sampling profiles | [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/mediaconnect/latest/ug/outputs-using-ndi.html) [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/mediaconnect/latest/ug/outputs-using-ndi.html) | | Audio codec support | [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/mediaconnect/latest/ug/outputs-using-ndi.html) If the source contains multiple audio PIDs, MediaConnect combines all the audio streams. However, this is only possible if the sample rates are the same across all of the PIDs. | | Supported resolutions | Supports resolutions from 480p up to 1080p | | Scan type | Supports both interlaced and progressive formats | | Frame rates | Supports the following frame rates : 23.98, 24, 25, 29.97, 30, 50, 59.94, 60 fps | ## Next steps To get started with NDI outputs, first [create a flow](flows-create.md) with NDI enabled, then [add an NDI output](outputs-add-ndi.md) to your flow. ## Additional resources + [Flow sizes and capabilities](flow-sizes-capabilities.md) + [Best practices](best-practices.md)