June 10, 2020

Software first steps: Configuring OBS – Adding sources – part 3

By jfbethlehem
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This post will be about adding video sources through NDI. NDI is difficult to set up but it will allow you to do some amazing things. It can, for example, let you add a guest speaker straight into the live stream using Skype. Or it can take a video source which is not connected to your machine at all and insert that into the stream.

NDI is a technology that was developed by NewTek. To get this to run, you will first need to install the NDI plugin for OBS. The manual to download and install this plugin for each of the operating systems can be found on the OBS plugins website:


Or the plugin writer’s Github page


After installing the NDI plugin, a new source will be available in OBS called ‘NDItm source’.

Adding someone through Skype

There will be times when you cannot be at the same place as someone you want to have in the stream. It could be because of a viral lockdown or because someone is in another country. Whatever the reason, OBS has you covered with this, thanks to a new technology that has emerged a few years ago.

Before adding the source, you should configure Skype to enable NDI. To do this, go to the Settings of Skype. Under Calling – Advanced, you will see an option stating ‘Allow NDItm usage’. Enable this and close the settings again.

After this setting, you can make a call to the person you wish to include into the live stream. Once the video call is set  up, go to OBS and add an ‘NDItm source’. In the Source Name, select the Skype NDI source, usually containing something like ‘Skype – usernameofwhoyoucalled’.   Set Bandwidth to ‘Highest’ and Sync to ‘Internal’. The rest you can leave default. Press ‘Ok’ to insert the new source into the scene and position the new source to your liking.

If you have issues with the video resizing for unknown reasons, this is most likely due to the fact that whoever you called through Skype has a bad internet connection. This makes Skype choose a lower resolution video and OBS just assumes the video should therefore be smaller on the screen. This is highly annoying but it can be fixed.

To fix this, right-click on the source in the ‘Sources’ panel. Select ‘Transform’ – ‘Edit transform’ in the menu. In the new screen, set the ‘Bounding box type’ to ‘Scale to inner bounds’. Close the screen. Now, right-click on the source again and select ‘Transform’ – ‘Fit to screen’. Click the padlock afterwards. This will ensure that the video will be full screen all the time, regardless of the incoming video signal. It might result in the video being a bit blocky if the signal is bad (which is normal as people watching online video are used to this) but people will not be surprised by a suddenly smaller video screen.

Using phone cameras

In passing, I mentioned using mobile phone cameras earlier. If you like to add additional cameras but do not have the budget for a completely new camera, you can use a mobile phone as an additional (mobile) camera. 

To use a mobile phone as a camera, you will need an iPhone with an NDI camera app installed, like NDIKUN or NewTek’s NDI HX Camera (both free). Unfortunately, for Android, there is no NDI camera app.

Once you have the app installed, open it and allow it access to the camera and microphone, if needed. If you are using the NDI HX Camera app, press the NDI-icon in the middle to start streaming (blue is on, white is off). Pressing the gear icon allows you to change a few settings like bandwidth usage, which camera is used and if you want the video stream to include sound.

If you are using the NDIKUN app, the only setting you can change is the device name (press the (i) icon). NDIKUN will start streaming immediately upon opening. 

The next step is to add it to OBS. This can be done by adding an ‘NDItm source’. In the source name, select your phone’s name, for example ‘MY-IPHONE (NDI-HX Camera)’. Leave the rest default and press ‘Ok’. Now place the new video stream in the location you prefer.