OpenLP support for NDI output

Can it be put onto the radar the ability to output via NDI (

there are a number of NDI endpoint devices from organisations such as birddog and magewell that take an NDI (over ethernet) signal and convert it back to HDMI/SDI for output in multiple destinations/ screens/projectors.
This would also simplify the way output is combined with streaming devices.

Thank you.
p.s. although I I am not conversant with Python, I would like to offer assist where I can


  • @MatthewN I added this to the list of Feature Requests....The development team will have to review and determine what they can do.
  • @MatthewN The team took a look at this appears the license for NDI is not compatible with the OpenLP license.  We will not be able to incorporate support for NDI due to the License issue.
  • aboabo
    edited January 2020
    We use Scan Converter (in NDI 4 tools from NewTek free of charge) to create an NDI source of the live display of OLP.
    NDI 4 tools are available here.
    Hope this helps.
  • @JohnM The NDI send and receive features are integrated in OBS Studio (obs-ndi plugin) which is also opensource software distributed under the GPL license.
    As far as I know OLP is distributed under the same GPL license.
    Using NDI in OLP should not be an issue.
    Am I missing something ?

  • @abo We are looking into this.....give me a bit and someone should post an update.
  • The obs-ndi plugin is not developed by OBS, and its compatibility with the GPL is questionable at best. The header files for the NDI SDK are under the MIT license (which is compatible with the GPL), but the rest of the SDK is not. Also, the obs-ndi plugin distributes a runtime library of the SDK, which is actually against the NDI SDK license.

    So I guess that if you wrote a plugin for OpenLP that could integrate with NDI's SDK, then you'd be in the same camp as OBS.

    Right now the OpenLP developers are pretty swamped, so I doubt any of them is going to pick this up, since there are less than 1% of our users requesting it.
  • @raoul Many thanks for your reply.

    Sorry, I am not fluent in english.
    I need to clarify my request.

    For this current topic "OpenLP support for NDI output" an easy workaround exists using NDI 4 Tools as mentioned above in the topic.

    My question about license compatibility came because I posted another post on this forum : "Feature request : video input"
    This is a feature that may help a lot churches that use projectors also for live video.
    Projector is shared between OpenLP and other equipment or application.
    Making OpenLP able to display video input will simplify a lot operation on projector.

    I am not expert on licensing.
    I know, because I installed OBS studio and obs-ndi plugin for my church, that NewTek totally support integration of NDI in OBS Studio since several years.
    There are several pages related to OBS studio on NewTek site. For example
    There are also many posts, articles, videos of reference companies on web that provide information about this integration.
    To make NDI available in OBS studio it is necessary to install obs-ndi plugin (GPL license) and the NDI Tools application which is free (not opensource) and owned by NewTek.The NDI Tools package provides the NewTek NDI drivers.
    My understanding is that NDI Tools are protected and obs-ndi plugin is only the interface between OBS studio and NDI Tools.

    Again I want to thank you making OpenLP a great tool for churches.
    God bless you
  • Count me as one of the 1%. NDI is one of the most powerful tools to come along in many years. Other presentation programs are already pocking up on this. It would be wise to look into this.
  • I took a look at the licencing because I was curious and wanted to confirm and indeed it is VERY restrictive and couldn't really be used in any Open Source project. It might be worth posting on the NewTek forums though as they seem to be pretty responsive on there and may not have considered something like OpenLP and may even be willing to provide a licence in support?

    Licence for Reference:
  • Question posted today on NewTek forum.
    English is not my native language and the legal terms in the NDI SDK license are unclear to me.
    Google translate provides an even more obscure translation
    Anyway I understand that the license seems extremely restrictive.
    I know that NDI is already integrated into GNU license opensource applications like OBS studio.

    My question is simple: do we have the right to freely use the NDI SDK in an open source software under GNU license?
    if yes : Good ! Question closed
    if no : What must be done step by step to be able to use the NDI SDK in the application as for the obs-ndi plugin in OBS studio?

  • @raoul : email reply received from NewTek
    First of all, I should say that we cannot offer legal advice and we do recommend that you feel comfortable with your license, etc... Specifically, you should be comfortable with the fact that NDI can be considered a system library as far as your application is concerned; this is up to your own interpretation. We believe that this is fine, but we also believe that you are the owner of your rights and should feel comfortable with them.

    With that said, I believe that you can do the following :
    1) Compile against NDI dynamically (we have an example).
    2) You can distribute the NDI header files with your code (they are under MIT license)
    3) You now can run and as long as the NDI run-time is installed your implementation will work and you are not distributing anything other than source code.

    Optional :
    4) You can offer the user if they want to download the "NDI Runtime" from your installer.

    This is the approach that the OBS plugin follows.
    Information received from

  • for what its worth, +1!!!1
    We spent all our budget on vMix and are trying to shoehorn as much ndi as possible into it.
  • +1 for NDI, but work around for those wanting something now... Why not use OBS with obs-ndi plugin and feed openLP and video inputs into OBS, which could run in the background. If you want easy scene control of OBS will it's in the background, use an Elgato StreamDeck.
  • Use scan converter to capture the output screen and if you're trying to setup a transparent NDI stream for lyrics use openlps custom stage view. I made one here:
  • @Ferman and @MichaelC   many thanks for your help.

    We are already using NewTek Scan Converter (and vMix Desktop Capture) to get NDI stream from OpenLP projector screen as I wrote above in this post.
    This workaround is working perfectly.

    However I was using this active post to discuss about NDI licensing constrains because we would like to push another topic : NDI Input described in this post

  • @raoul @JohnM ; I perfectlty understand the trouble with NDI licensing.

    I understand that considering NDI Runtime as a system library can be also confusing.
    However from my perspective, this is only my understanding, I do not make difference between NDI Runtime and Powerpoint.
    We can consider both as external applications that OpenLP uses for some features.
    Both do not provide source code.
    Both must be installed out of OpenLP

    The only difference is the cost :
    - NDI Runtime is part of NDI Tools which are free of charge and publicly downloadable <3
    - PowerPoint is not free :'(

    May I ask you to consider again the two requests, may be in the form of another plugin : NDI Output/Input

    Many thanks for your help
  • @abo I see what you're trying to do. I am not sure if this is a universal use case that would significantly benefit everyone. It would obviously be cool but I doubt a majority of people would or could use this.

    One possible workaround that OpenLP might be able to do is since NDI tools is free and they provide a VLC plugin to pull a stream. From my understanding in the past VLC was used to play videos for openlp. If that is still true they might be able to reconfigure how media gets input and have an IP option for ndi streams and then when you go to an NDI slide it uses vlc.
  • @Ferman Many thanks for your help.
    Unfortunately NDI VLC plugin looks like not being able to receive/consume NDI stream.
    It is able to convert any possible VLC source into NDI stream and push it to network.but I do not find a way to get reverse operation.
  • @abo ah, I guess you're right. I look at the vlc features. :/

  • Hi...I suppose with a deticated, closed-off Network switch and some extra ethernet cards you could do some truely amazing things with this, plus save a good couple of bucks on capture cards for each of your other PC's.
    This is nothing short of amazing, I'm even using the official 20$ NDI app from AppleStore to connect my Iphone to this and I only see possibilities with this technology. To the best of my knowledge the limitations will be within your home network.
  • You are right. I found a lot of advantages to use NDI instead of traditional video connections (sdi, hdmi, usb).
    one source to multiple destinations : any NDI source on the network can serve several displays
    low cost cabling (Ethernet Gb) up to 100m
    low cost (20$) camera investment for iPhone/iPad
  • Hi everyone...thanks for the good works...please NDI plugin is seriously needed for openlp. pls!!!
  • Pls add me as the 1% requesting for the NDI plugin...thanks
  • So there's now a opensource implementation of the ndi protocol which avoids the licence incompatibilitie issues
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