To create an NDI stream, choose software on the device that has the picture or sound you want to send, then let receiving software discover and add that source over the network. A screen-capture tool, a vMix output and a phone camera app are different senders; they do not all work the same way or appear automatically on every network.
This guide separates those two jobs: creating the source and receiving it. First decide what you want to send, then check network visibility, and only then select the source in vMix or another NDI receiver.
How an NDI source reaches vMix
NDI carries audio and video from a sending device or application to compatible receiving software on a network. Think of it as a hand-off: the sender publishes a named source, and a receiver searches for it. Starting a sender does not by itself add an input to vMix, and opening vMix does not make a screen or phone send video.
There are two directions to keep distinct. If a laptop desktop or phone camera needs to appear in vMix, the sender runs on that device and vMix receives it. If vMix needs to send its Program mix to another NDI-enabled application, you enable a vMix NDI output and select that output in the other application. The setup and troubleshooting differ depending on which direction you mean when you ask, “How do I create an NDI stream?”
NDI source discovery depends on network conditions, device support and compatible software. vMix’s NDI input guide explains that sources on the network can be added through its NDI input workflow. NDI’s Scan Converter documentation describes sharing a computer screen with another NDI-enabled device. Those are descriptions of the intended workflow, not a promise that every router, Wi-Fi network or firewall will allow discovery.
For a small studio, start with the media you want to send and the receiver you will use. A presentation operator usually needs a desktop or application window; a second vMix machine may need the production output; a presenter on location may need a camera feed from a phone. Keeping sender and receiver roles clear makes it easier to test one part at a time.
Choose the source: screen, production, or mobile
Choose a tool according to the image and sound you need, rather than installing several senders and hoping one is visible. A screen-sharing tool captures a computer display; a production output carries a composed feed; a mobile screen app shares phone display content; and a camera app sends the phone camera. A phone’s screen and camera are not interchangeable sources.
| What you want to send | Sender to consider | Main check before relying on it |
|---|---|---|
| Computer desktop or application | NDI Scan Converter or the appropriate screen capture tool for your platform | Confirm capture area, audio source and network visibility |
| vMix Program or another production feed | vMix NDI output | Enable the intended output and confirm it is available in your edition |
| iPhone screen | NDI Capture | Confirm current app availability and that screen-sharing is the task |
| Mobile camera video | An NDI-capable camera app, such as Larix Broadcaster where supported | Check the current app, platform and NDI output feature |
For Windows screen capture, NDI Screen Capture HX is a separate tool documented by NDI. Its HX workflow uses GPU acceleration and H.264 or HEVC encoding; check that the receiving software supports the mode you select. NDI describes HX as a lower-bitrate option than High Bandwidth, which can help where bandwidth is constrained, but it is not automatically the right choice for every receiver or machine. See NDI’s encoding documentation for the distinction between formats and codecs.
If the source and receiver are on separate machines, use a local network that permits both discovery and media traffic. For the Mac Scan Converter tool, NDI’s product page lists a 1 Gbps local-area network minimum for that offering; treat this as a product-specific requirement, not a universal bandwidth figure for every NDI setup. A wired connection can make a fixed studio arrangement easier to diagnose, while Wi-Fi can be practical for a phone if coverage and capacity are adequate.
Create a screen source with Scan Converter
For a computer desktop or application, NDI Scan Converter is the screen-oriented sender. NDI’s Mac instructions describe installing NDI Tools, launching Scan Converter and choosing whether to share the full desktop or an application window from its File menu. Windows users should follow the current instructions for the appropriate NDI screen-capture tool rather than assume the Mac menu sequence applies to their version.
On macOS, grant the requested screen recording permission when prompted. Select the capture target deliberately: sharing one application window reduces the chance that messages, unrelated browser tabs or desktop notifications appear in the source. If the receiving production will crop or place the image, confirm the application is at a useful size and that menus or controls are not obscuring the content.
Audio needs its own check. The Mac Scan Converter workflow uses macOS sound settings to select captured system sound, and the tool includes a mute option. Choose the correct system output before testing, then listen in the receiving application; a moving picture alone does not show that audio is being sent. If you only need a silent screen, mute it intentionally rather than leaving an uncertain audio path active.
On Windows, NDI Screen Capture HX offers settings for bandwidth, resolution, frame rate, audio source and pointer capture. Make a simple test with the intended resolution and frame rate, then check the result in the receiver before adding more sources. Higher image detail and frame rate can increase processing and network demands; HX’s GPU-accelerated H.264/HEVC path may suit a constrained link, but the receiver and graphics capability still matter.
If screen capture is part of a long-running YouTube production, plan what the audience should see when the operator changes windows or the computer display sleeps. A presentation that goes blank during a break can look like a broadcast failure even if the NDI connection is still active. For an entirely different workflow, such as looping prepared footage, a guide to running a 24/7 playlist with FFmpeg may be more relevant than capturing a live desktop.
Send a production mix from vMix
To send a vMix production to another application or machine, enable the NDI output you need in vMix settings. The Program output is the usual choice when the receiver should get the composed show, and it carries the Master stereo mix according to the vMix guide. Other outputs can be configured independently, and individual cameras, calls or audio inputs can also be exported as NDI sources where the workflow calls for them.
In vMix, open Settings, go to Outputs / NDI, and enable the intended feed. Then give the receiving operator a clear source description, if your workflow allows it, so they can distinguish Program from a camera or another output. Check the output in the receiver before the live session; an enabled output is a sender configuration, not proof that the receiver can see or decode it.
The number of outputs available depends on the vMix edition, so consult the current vMix feature comparison rather than assuming every installation has the same capacity. If you need Program plus separate clean feeds, identify those requirements before production and verify which outputs your setup can provide. Do not enable an output you do not need: keeping the feed list understandable helps the receiving operator choose the right one.
If your goal is to bring an external NDI source into vMix, you do not configure an output for that. Use Add Input and select the NDI / Desktop Capture route instead. Confusing the two directions is a common reason for thinking that a source has disappeared: an output sends from vMix, while an input receives into it.
Use a mobile device as an NDI source
A phone can be useful when a camera needs to move around a room, but the available workflow depends on the specific device, app, operating system and network. Decide first whether you want to transmit the phone’s display or its camera image. For an iPhone screen, NDI offers NDI Capture; for camera video, NDI’s product finder lists Larix Broadcaster for iOS and Android with NDI HX2 output. App features and compatibility can change, so confirm the current listing and the chosen receiver’s support before an event.
For a camera feed, install and configure an app that explicitly offers an NDI output on your device. Grant camera and microphone permissions as appropriate, select the desired camera and audio source, and start the send function. Then check whether the app reports an active source and whether the receiving software can see it. An app that streams by another protocol or only captures locally is not necessarily an NDI sender.
For a phone screen, use a screen-sharing app that supports NDI on that platform. NDI Capture is described for iPhone screen sharing; do not assume that an Android device has the same app or workflow. If you need to show slides or a mobile app interface, test screen recording permissions and confirm that protected content or operating-system prompts do not prevent the image from appearing as expected.
Wireless use is convenient, but a busy access point, weak signal or network isolation can interrupt discovery or the picture. Keep the phone and receiver on the intended network, avoid changing Wi-Fi networks during the test, and monitor battery and heat during longer sessions. If you need to assess the upstream path for the eventual YouTube broadcast, this guide to checking a stream over Indian mobile data covers a related but separate network test: successful NDI on a local network does not prove that the internet uplink is stable.
NDI HX is designed for lower bitrate than NDI High Bandwidth, using compressed video formats such as H.264 or HEVC in the documented HX path. This can be useful for a mobile source on limited bandwidth, but it adds a compatibility and processing consideration. Match the app’s mode to what the receiving software accepts, and test motion, audio sync and image quality on the actual network you intend to use.
Find and add the source in receiving software
Once the sender is active, open the receiving application and use its NDI source browser. In vMix, choose Add Input, then NDI / Desktop Capture, and select the desired detected source. vMix presents available sources with previews and groups them by computer or device, which helps when a studio has several senders. If the intended name is not listed, do not add a similarly named source without checking its preview and sender.
In other NDI-enabled software, the wording varies, but the task is similar: open the source or input browser and select the advertised sender. NDI’s Scan Converter instructions mention using an NDI-enabled application such as Video Monitor to view the output. A receiver may refresh its list on its own or require reopening the browser; consult that application’s current instructions if its controls differ.
After selection, verify more than presence in a menu. Look at the preview for the correct screen, camera or production mix; listen for the expected audio; and check that motion is smooth enough for the intended use. If the source is a production feed, confirm that it is Program rather than Preview or a camera-only output. If it is a screen source, confirm that system audio is present only when expected.
For a wireless or unstable NDI input, vMix offers Low Bandwidth Mode and an increased buffer option. Its guide says increasing the buffer can add approximately five frames of latency; that may smooth a variable connection but makes the feed less immediate. A discussion or camera cut may tolerate some delay, while interactive timing may not. Test the choice in context rather than enabling it by habit.
NDI is only one leg of a live workflow. If the received image is later encoded for YouTube, check the output profile and continuity separately; an NDI source that looks correct in vMix can still be delivered with the wrong encode settings. See the 1080p 30fps animation bitrate guide for output encoding considerations, and keep local source quality distinct from YouTube’s incoming stream settings.
Troubleshoot sources vMix cannot see
When vMix cannot see a source, work from the sender outward. Confirm the sending app is open, the correct sharing or NDI output is active, and the source is not paused. Check the sender’s own preview or status first. If the sender is not actually publishing, changing vMix settings will not make a source appear.
Next, confirm that both devices are connected to the intended local network. A computer on Ethernet and a phone on Wi-Fi may be on the same LAN, but guest Wi-Fi, client isolation, VPN routing or separate subnets can prevent devices from discovering one another. Check the network interface selected on each computer, especially if a machine has both Wi-Fi and Ethernet active. These are practical checks for a network-discovery workflow, not a guarantee that any particular network policy is configured correctly.
Review local firewall and network security settings on sender and receiver. They must permit the relevant NDI discovery and media traffic; the right adjustment depends on the operating system and network policy. Do not open arbitrary ports based on an unverified list. If this is a managed workplace, school or venue network, ask its administrator whether device-to-device discovery is allowed rather than weakening a policy you do not control.
If a source is visible but black, frozen or silent, separate the symptoms. For a black screen, verify screen capture permission and that the correct desktop or window is selected. For missing audio, check the sender’s selected audio source, mute state and permissions, then inspect the receiving input’s audio settings. For a frozen or stuttering image, compare a wired connection with Wi-Fi if practical, reduce capture demands, or test an HX mode if both ends support it.
If the source appears but playback is unstable, vMix’s Low Bandwidth Mode may reduce network demand, while Increase Buffer Size trades responsiveness for smoother playback on variable links. The guide’s approximate five-frame latency note applies to the buffer option, not to every NDI configuration. Change one setting at a time and observe whether the result improves; otherwise you will not know which adjustment mattered.
For a multi-device setup, make a short source inventory: sender device, source name, intended receiver, audio needed, connection type and tested output. This prevents an operator from selecting a phone preview when they need the program feed, or routing an unmuted desktop into a show. For a wider 24/7 operation, the audio continuity checklist for an ocean ambience stream is useful for thinking about monitoring after a source has been added; it addresses a different failure point from NDI discovery.
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FAQ
How do I send my screen to vMix over NDI?
Run a screen sender such as NDI Scan Converter or the appropriate platform capture tool, choose the desktop or application to share, and then add the detected source in vMix through Add Input and NDI / Desktop Capture. Check screen-capture permissions and audio selection separately. The devices must be on a network that permits discovery and traffic.
How do I use my phone as an NDI camera?
Use a mobile camera app that explicitly supports NDI output for your particular phone and operating system, then start its send function and select it in the receiver. NDI’s product finder lists Larix Broadcaster with NDI HX2 output for iOS and Android, but verify current app support and receiver compatibility before relying on it. A phone screen-sharing app is a different workflow from a camera source.
Why can’t vMix see my NDI source?
Confirm that the sender is active, both devices are on the intended network, and firewall or network policy does not block discovery between them. Check active network interfaces and, on Wi-Fi, whether guest mode or client isolation separates devices. If the source is visible but unusable, investigate capture permissions, audio selection, receiver compatibility and network stability.
Should I choose NDI HX or High Bandwidth?
Choose according to the sender’s available modes, receiver compatibility, network capacity and the processing capability of the devices. HX uses a lower-bitrate compressed path and can suit constrained links, while High Bandwidth is a different format path with different demands. Test the actual source and receiver together rather than assuming one mode is always better.