OBS 31: frames freeze with multiple capture devices

angeloruggieridj

angeloruggieridj

New Member

OBS Studio Log URL​

https://obsproject.com/logs/swQiLe8F1M23NyAr

Expected Behavior​

Stable flow using more than one capture device card (in this case Elgato CamLink 4K).

Current Behavior​

Using two Elgato CamLink 4K devices for multiple camera sometimes the video stream in Preview or On-Air it's not fluid (visibile on 0:16 of the following video).

As the example video, there are some seconds where I notice it on Preview and On-Air panels but also the stream and the recording is also affected.

The configuration for both of source is:

Other info:

  • input stream coming from both cameras are 1080p at 50fps
  • Canva dimension is 1920x1080p, 50fps
  • downscale dimension is setted to 1280x720p
  • Recording use the same encoder as the live stream.
Both of CamLink are connected to a USB 3.2 hub 10Gbps ports.
I've tried also using two independent and different USB hub, same problem occours.
Using also two independent USB-C ports and not a hub (considering that Mac has only two USB-C ports) have also this problem.

Using the same configuration (single hub with the two Camlink connected) and selecting one of the Camlink for Skype (for example) doesn't verify the problem, so the video has not lag or freeze.

Steps to Reproduce​

  1. Connect two video capture devices
  2. Switch between them
 
J

jet7

New Member
On MacBook M1/2?

OS version?

Having the same issue!

And this issue has plaqued OBS at least 6+ months!

OBS dropping frames and getting these "surges" repeately

This issue has persist over 8 months now. It happens even when OBS is not streaming or recording at all. The preview windows shows clearly that it drops frames. Then suddenly it is normal again without any missed frames. And this happens over and over again.... Have re-installed OS and...
obsproject.com obsproject.com
( OBS Forum: "Awaiting approval before being displayed publicly.")
 
Last edited:
J

jet7

New Member
Since it takes ages for this new thread to get approved, I will post it here also..


OBS dropping frames and getting these "surges" repeately​

This issue has persist over 8 months now.

It happens even when OBS is not streaming or recording at all.

The preview windows shows clearly that it drops frames. Then suddenly it is normal again without any missed frames. And this happens over and over again....

Have re-installed OS and everything to te latest versions.

Even changed the power supply to a beefier one.

Setup:
MacBook Air M2, 8 GB RAM.
Latest MacOS
Latest OBS

Full HD video at 25 fps is coming in from BMD UltraStudio Recorder 3G SDI with Thunderbolt 3 cable.
Few NDI sources are also brought in from ProPresenter

Before this issue started to manifest we had no issues at all even when we used Full HD at 50 fps!

This issue is also present on our MacBook Air M1, 8 GB RAM that has similar inputs.
 
J

jet7

New Member
To me this seems some kind of weird Sync -issue OBS is having and it happens at least with recent OBS and MacOS.

And the bad behaviour seems to escalate when "changing/swiping screens / apps" on MacOS and then the result is very choppy streams as many on the forum has already mentioned.
 
Last edited:
J

jet7

New Member
Here is a good example:

- YouTube

Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube.
youtu.be youtu.be

OBS is used here to bring all layers together and stream to YouTube and record the final output on Mac.

Flawless mixed SDI signal is coming from vMix to OBS 31.0
 
Last edited:
J

jet7

New Member
I'm on an iMac and fairly new to OBS, but technically savvy too. I have several apps open including OBS. Whenever I switch between apps using the keyboard shortcut CMD + Tab, OBS generates an error message.
Click to expand...

Switching Apps Keeps Generating Error Message From OBS

I'm on an iMac and fairly new to OBS, but technically savvy too. I have several apps open including OBS. Whenever I switch between apps using the keyboard shortcut CMD + Tab, OBS generates an error message. It's not the end of the world, but it's more of a nuisance. Is there any way to stop...
obsproject.com obsproject.com
Click to expand...

Interesting. Could that be the cause one of issues talked above?
 
angeloruggieridj

angeloruggieridj

New Member
jet7 said:
On MacBook M1/2?

OS version?

Having the same issue!

And this issue has plaqued OBS at least 6+ months!

OBS dropping frames and getting these "surges" repeately

This issue has persist over 8 months now. It happens even when OBS is not streaming or recording at all. The preview windows shows clearly that it drops frames. Then suddenly it is normal again without any missed frames. And this happens over and over again.... Have re-installed OS and...
obsproject.com obsproject.com
( OBS Forum: "Awaiting approval before being displayed publicly.")
Click to expand...
MacBook Pro M1 / 16 GB of RAM

OS: macOS Sequoia 15.2
 
A

AaronD

Active Member
angeloruggieridj said:
Using two Elgato CamLink 4K devices for multiple camera...
...
...Both of CamLink are connected to a USB 3.2 hub 10Gbps ports.
I've tried also using two independent and different USB hub, same problem occours.
Using also two independent USB-C ports and not a hub (considering that Mac has only two USB-C ports) have also this problem.
Click to expand...
I think the problem is USB itself, not the captures, and not OBS.

The data rate that is required for a good HD video capture, is over half of what even "fast" USB can support. So one is okay, but when you add a second, it can't keep up.

If you have multiple USB controllers, then you can have one good capture per controller, but if you only have one controller and an internal hub (cheaper to build that way), then you're limited to just one.

---

How portable is your rig? Or how portable does it have to be? If you can have a desktop tower instead of a laptop, then you can use a multi-input PCIe capture card instead of USB. Then all of its inputs are good simultaneously, and it's often cheaper per input than good USB too.
 
J

jet7

New Member
AaronD said:
I think the problem is USB itself, not the captures, and not OBS.

The data rate that is required for a good HD video capture, is over half of what even "fast" USB can support. So one is okay, but when you add a second, it can't keep up.

If you have multiple USB controllers, then you can have one good capture per controller, but if you only have one controller and an internal hub (cheaper to build that way), then you're limited to just one.
Click to expand...

So what about when connected with Thunderbolt 3/4 with Thunderbolt equipped hardware (BMD UltraStudio Recorder 3G) and still having exactly the same issue?

There is definately something very wrong with the latest OBS-versions at least on the macOS-side.
 
Last edited:
A

AaronD

Active Member
jet7 said:
So what about when connected with Thunderbolt 3 and having exactly the same problems?
Click to expand...
What's the bandwidth? In other words, how much data can it actually support? And how much data do you actually need? If the numbers don't line up, then yes, it'll have the same problem.

Also be aware, that the advertised bandwidth may be higher than the usable throughput, because advertisers like to inflate their numbers. Including the overhead that keeps everything organized, is an easy way to do that. You want the usable throughput, not the raw bit-clock.

Beyond that:
I'm not actually a Mac guy, so I'm not particularly familiar with Mac-specific things. (Thunderbolt) I'm only here in this subforum, because most of what shows up here applies in general and is not actually Mac-specific. (shoving data through a hose)
 
R

rockbottom

Active Member
I don't run a mac but noticed your Distro plugin install should be using NDI tools or runtime v6, you're still on v5. Might want to clean this up. Double check all of your plugins.

18:09:49.404: [DistroAV] obs_module_load: you can haz DistroAV (Version 6.0.0)
18:09:49.404: [DistroAV] obs_module_load: Qt Version: 6.6.3 (runtime), 6.6.2 (compiled)
18:09:49.405: DEPRECATION: obs_frontend_get_global_config is deprecated. Read from global or user configuration explicitly instead.
18:09:49.405: DEPRECATION: obs_frontend_get_global_config is deprecated. Read from global or user configuration explicitly instead.
18:09:49.406: [DistroAV] load_ndilib: Trying '/usr/lib/libndi.dylib'
18:09:49.406: [DistroAV] load_ndilib: Trying '/usr/local/lib/libndi.dylib'
18:09:49.406: [DistroAV] load_ndilib: Found '/usr/local/lib/libndi.dylib'; attempting to load NDI library...
18:09:49.418: [DistroAV] load_ndilib: NDI library loaded successfully
18:09:49.418: [DistroAV] load_ndilib: NDIlib_v5_load found
18:09:49.418: [DistroAV] obs_module_load: NDI library initialized successfully ('NDI SDK APPLE 09:59:07 Feb 2 2023 5.5.3')

github.com

1. Installation

DistroAV (formerly OBS-NDI): NDI integration for OBS Studio - DistroAV/DistroAV
github.com github.com
 
A

AaronD

Active Member
jet7 said:
Come on!
Of course it has the needed bandwidth! It even worked 50 fps with OBS once upon a time..
Click to expand...
Numbers...

Just "it worked before", could have been with different software that did some "theatrical magic", that the new version doesn't do anymore. It didn't actually do what you thought it was doing, and now you're seeing the actual, unbreakable physics.
(telling the capture cards to degrade themselves, for one possibility...)

Checking for more malicious intrusions, could be part of it too.
A big part of why Firewire died, was security. It was significantly faster than USB at the time, because it went directly to RAM and bypassed the CPU. Then the CPU eventually got around to working with whatever "just showed up" there. But that also allowed malicious code to bypass all the security checks. So the clearly superior thing in a world with no threats, faded away in a world that does have threats.

So if a security patch kills performance, you should still be grateful that you're not getting hacked, and keep those patches coming. And find another way to do things that keeps all of the patches up to date.
 
J

jet7

New Member
The log file says:
Decklink API Compiled version 12.0
Decklink API Installed version 14.4

Version 12.0 date back to January 2021.
 
Last edited:
You must log in or register to reply here.
Top