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Welcome to the PTZOptics forum(s)!

This thread has been created for end users to discuss the topic of differences between NDI and NDI|HX and when it is best to use each option.

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There are two (2) major considerations when contemplating using an NDI vs an NDI|HX source

  • bandwidth 
  • quality

So let's start with bandwidth... one of the major advantages to using NDI|HX is the lower bandwidth consumption presented by the HX source.

If you look at bandwidth consumption for NDI versus NDI|HX you will see, on average, an eight (8) fold increase in bandwidth consumption.

If we take a moment to look at this in a real world application where we have a 1 Gb bottleneck in our network we would be limited to less than ten (10) NDI sources.

Now if we look at that same 1 Gb bottleneck using NDI|HX we can still pass approximately eighty (80) NDI|HX sources via that same connection.

Having the lower bandwidth consumption allows you to be more flexible with your deployments.

Now let's chat about the differences in quality between NDI and NDI|HX

The additional bandwidth consumed by NDI is not for nothing; you do gain an improvement in the color space as well as a mostly uncompressed video feed.

For high budget productions, archival purposes or post production scenarios using NDI may be a better fit due to the higher quality of the video to work with.

When looking at NDI vs NDI|HX or even your production at large one of the considerations that needs to be made is "HOW are my end users going to consumer this content?"

If your are using YouTube or Facebook then there isn't much reason to bother with super high resolutions and super high frame rates... as they will be lost in translation to the platform and possibly make the production less reliable.

This can be things such as taxing the production PC or requiring a large reliable pipeline for streaming your production out when using these high quality feeds.

If the platform even supports those higher resolutions and frame rates how your end users are consuming the content can be another key factor to consider

If the end users are viewing this on their mobile devices there is little point in making a 4K production; even if they are viewing them on their home PC it is unlikely they would want to watch in 4K unless you give them a good reason.

These are just some initial thoughts on NDI vs NDI|HX and I look forward to any input our community wishes to add to these discussions on an ever evolving topic.

I think there is another variable for NDI vs NDI HX comparison: latency.

From my reading different forums, I'm getting, that going with HX  introduces 40-50 ms latency. Not sure, if it's true.

So, is it possible to switch PTZOptics camera to NDI (non HX) mode?

I see, that I can set "NDI Preset" to "Off", but "First stream" is still set to "H264".


NDI HX latency from the cameras should be around the 200 ms mark. The cameras do not offer a "Non HX" NDI mode. The cameras still uses H264 for its compression method for RTSP and RTMP, as well as NDI. The NDI preset is just a collection of settings for the first and second stream to utilize the correct settings for different, preset, NDI resolutions and framerates. 

So what “stream” does NDI HX populate?

Hi @Omar Simpson,

NDI|HX on the PTZOptics camera line utilizes both Stream 1 & Stream 2 in the following ways.

For a majority of users the standard connection will be to Stream 1, or the high-definition stream.

If you tell the NDI software to connect using SD / "low-bandwidth" the connection will be to Stream 2.

The other area where you may see both utilized is if you are using a NewTek Tricaster; the Tricaster will use Stream 1 for anything in Preview or Live but uses Stream 2 for any thumbnail previews.

If you have any follow-up questions about NDI|HX on the PTZOptics camera line please do not hesitate to return to the forums.

So if turn the NDI On …and it’s populates the settings…And select low..what do I need to set the selection just below the NDI on? Also I see when I do select NDI on it switches whatever I had the second stream set for…it changes it to also h264 with settings that are different from the “first” H264… Is this correct? Also I am getting a good 1 second Audio delay…where I had very little before selecting the NDI “On”…BTW we use line in Audio and this is only on one camera…Am I missing a setting(s)

Hi Omar Simpson,

The NDI Preset just sets a preset configuration of the first and second stream settings.  Low is for 720p60, medium is 1080p30, and high is 1080p60.

You can set the second stream to be MJPEG and the NDI still works, but you cannot do the same to the first stream. 

1 second of sync is a bit much for the NDI feed with the audio running into the camera. I would make sure the unit is fully firmware updated and go from there but that is out of the ordinary for the NDI cameras.

So, the question then is, given the cameras don't currently implement full fat NON HX version of NDI, which people with the network capacity will take advantage of, for the ultra low latency... when WILL the NON HX version of NDI be implemented?

The scenario we have is, to be able to show a live feed inside the church for weddings. When a couple are saying their vows, we need latency sub 20ms. HX isn't going to work.

Our cameras are not going to use anything aside from NDI HX in the future. If you need sub 20 ms latency I would look at other camera manufactures as the PTZOptics will not ever get that low. 

I still can't get my camera to stop swinging all the way in and all the way out between presets... even those that are at the exact same distance from the lens!  Turning the "lock focus" button does not fix the problem (actually it makes it even worse if I manually zoom in or out even a little bit.  After a year of headaches and not being able to fix the many lens problems I've had from the beginning, I'm starting to think I have a BAD CAMERA.  I need to have this fixed.  What do you recommend?

Hi Gene,

We would probably want to address this one direct with support, 484 593 2584 8am - 6pm EST M-F. We can try and get on the same page with the issue and if it is a bad camera, we can set up an RMA to bring it back for repair or replacement under the warranty. 

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