4. Extras
WORK IN PROGRESS!
This page is mostly dedicated to quirks and advice for using NDI in different scenarios, as well as advice on what to do and what to avoid.
I will try to keep this as organised as possible!
NDI has some network requirements and advice that everyone should and must follow, otherwise there will be unexpected and undesirable behaviour.
NDI recommends a gigabit speeds for most of their use-cases, with DistroAV you should run always have a minimum of gigabit speeds, don't confuse it with your internet speed, it is your local network speed!
Whilst it's possible to use OBS with DistroAV through wireless networks, we don't recommend it. The outcome might vary and cause video and audio stuttering or directly suffer sync and delay issues. NDI keeps a table of bandwidth and resolutions in case you ever need to know.
OBS discourages too the use of wireless networks.
I personally haven't had luck with high performance Wifi5 networks, only with Wifi6 with some tweaks.
NDI has recommendations from switch configurations to network card settings to use for best performance within their whitepaper.
Whilst network performance it is important, not every network card has good drivers, keep this in mind when choosing if you're planning on building a new rig or simply upgrading your current one.
Killer Networks has been known to cause issues with their software utilities.
Intel 2.5G (i225-V) is known to be faulty within most of their hardware revisions, Intel has documented it within this press release/official communication.
There is currently an investigation about some USB Realtek drivers to have unexpected behaviour within Windows 11, I have confirmed some weird behaviour within Windows 10 as well.
Intel pcie network cards tend to be very performing and easily available with good driver support.
I'd like to make a list of known issues and low performing cards, feel free to create an issue to expand these!
Many seem to have gotten the wrong idea over the years with OBS and it's requirements. No, you can't game at 300fps and expect OBS and NDI to perform well, for that case/scenario you need a capture card.
OBS requires some Cpu and Gpu to compose the scene and everything within it, regardless of your hardware specs.
OBS has a page with information on regards to these.
Everyone must understand the limitations of the hardware!
Whilst it's possible to run high fps and high resolution, it requires a lot of tweaking and testing!
My own setup consists of a Ryzen 9 5900x and a RTX 3080 10G and I've ran for years OBS at 1440p and 60fps while I game as much as possible at 120fps. It's very smooth but requires a lot of patience, testing and to have optimised scenes.
My primary goal is to not overuse the graphics card in ways that would cause delay or for OBS to miss frames or to suffer any form of encoder overloaded.
I'm among the very few who can use HAGS with OBS and have a better VRAM management.
Don't use window capture, it's a performance hog unless it's completely needed. Use Game Capture foreground with hotkey as much as possible to have the best performance and the smoothest experience!
Using that capture method won't work with Unreal Engine games if you have MSI Afterburner with Rivaturner (RTSS), simply disable the overlay within RTSS or blacklist the program within it.
Audio and video sync is crucial in many instances, specially during streaming!
We've already stablished within the previous paragraph how important is to keep everything tidy to have the audio and the video reasonable within limits. What else now?
Since OBS 28 released, they added an option for "Low latency Audio Buffering Mode" for NDI and Decklink outputs.
It's located within the Settings > Audio menu and everyone who uses NDI should enable it to avoid NDI having latency buffer increasing overtime, which causes audio and video sync issues.
If you use image sources within OBS, you might have noticed it tends to lag when showing or hiding said source, causing OBS to lag or directly to freeze, causing the NDI feed to become desync'ed and to not be recoverable unless OBS is restarted!
In my search to try and optimize my workflow as much as possible I found this plugin and a good explanation of how this happens.
Some USB Audio devices can cause audio buffer issues within OBS, causing NDI audio to break. You can easily inspect your logs with OBS Log Analyzer, whilst some can be solved with investigating their drivers, it can be tedious.
Since NDI can be used in many different scenarios with many types of workflows, many of our users (myself included) use it but not limited for gaming and streaming.
Most don't know what settings to use for gaming, here I'll shed some light.
For the Audio/Video Sync you should use Source Timing. For the latency Mode I'd personally suggest Low.
Audio / Video Sync depends in use-case, some have found better results for their workflow to choose Network sync instead of source timing.
Latency mode in Low has had the best results overtime after years of use with both Audio and Video sources for us. Make sure to test beforehand!
NDI and it's many different workflows.
The Main Output within DistroAV contains both OBS Audio and Video. What if you want to have them be separate?
For quite a long time, most users who use OBS to game and stream have relied on Desktop audio. There is many reasons why one wouldn't want that.. I'll name a few.
Audio level balancing.
Post production & editing.
Sound alerts.
Music.
Not only having good audio levels with the Main Output can be tedious even if you use filters to try and balance everything within reason, it tends to be very messy and inaccurate because you are trying to have a blend of many kinds of sounds through only one output.
With DistroAV NDI filters you can solve that. You can add them to ANY source within OBS, be your sound alerts, your microphone or simply your game or music audio.
Without getting too caught up on the how's, I made a quick write up of it within the discord server
If you decide to use OBS's built in Application Audio Capture (beta), be warned. There is issues with audio breaking randomly.
You can hear an example of it in one of my recordings: Timestamp 1 and Timestamp 2
The issue is supposed to be fixed within Windows 11. It's not an issue within NDI I can confirm that, the issue used to be more common with surround audio but it has improved since 2024.
Well well well.. since these is a rabbit hole I believe I should leave these here.
Whilst it is possible to send sources with alpha transparency with NDI as I wrote here, It is not widely known what is the best ways to record with alpha transparency, for Vtubing it may be a must whereas green keeying or green screening isn't good enough.
You need the following settings:
Colour Format: BRGA
Colour Space: sRGB
Colour Range: Full
On output settings there is several ways to acomplish it. I simply suggest you use MOV.. I was able to achieve it with these settings within the advanced tab:
As you can see within Premiere Pro, the avatar has been fully recorded with alpha transparency and it can be used for editing without issues! Ignore the extra settings that aren't pointed with the peach dot!
That being said I do not recommend any of these for real time usage since they are not hardware accelerated! They will rely on your CPU to encode it!
These were tested with Obs 31.1.0 RC1 and DistroAV 6.1.1, the avatar was sent from another computer through NDI with Alpha transparency as explained here