Bad latency

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Nickl23

New Member
Hello,
I am more of an audio guy and fairly new to video recording. I have set up OBS as a recording device for YouTube videos. I have the camera and audio input working but there is a significant delay in the monitoring of both input signals. The video and audio are perfectly aligned, but about a second late - which makes monitoring difficult. I can monitor the audio separately if I have to because my studio is set up that way, but I would like to be able to monitor everything in real time. Any help or insight is greatly appreciated.
Thanks,
Nick
Windows 10 Home, 64 bit, 128 GB RAM, AMD 7900 XTS.
 
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AaronD

Active Member
1/4-second latency is usually considered "pretty good" for live video. Lots of things between the camera and the display have their own frame buffers, and each one adds at least 1 frame of latency. At 30fps, it doesn't take very many of those to become a problem.

A real-time or low-latency kernel helps a lot with that. Windows is not known for that. Sometimes it works, sometimes it doesn't. Maybe you need different hardware and then Windows will be fine. Maybe you need a low-latency flavor of Linux on the same hardware, and that'll be fine. It's kinda hard for me to tell from here.

For reference, my media rig is a 2015 Dell Precision M6800 Mobile Workstation, running Ubuntu Studio Linux, which comes out of the box with a low-latency kernel and a bunch of media stuff preinstalled and "just working".

Ubuntu Studio – A free and open operating system for creative people.

ubuntustudio.org ubuntustudio.org
1695408045336.png

I'm just under 1/4-second with an HDMI camera through a name-brand USB capture...after I mess with the color settings and put them back. Not sure why that's needed, but it's about 1 second before I do that. So I've automated that in the Advanced Scene Switcher plugin:

Advanced Scene Switcher

This plugin will allow you to automate various tasks using "Macros". Macros consist of a list of conditions under which a list of actions will be performed. Examples and guides can be found in the wiki. Feel free to contribute! If you run...
obsproject.com obsproject.com
 
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Lawrence_SoCal

Active Member
Aaron knows far more about audio than I do.... but taking a step back, especially if you are new to OBS Studio (or similar real-time compositing apps)...
Your description makes me think you mean your Audio is NOT being captured on the Video device, right? you have a separate mic connected somehow to computer, with separate video feed, right? Assuming my guess is correct, the issue is that typically video takes a lot more processing than audio, so audio tends to be 'ahead' of the video. Because of this, OBS Studio (and similar tools) have an option to delay Audio to get them into sync
Just in case hardware is underpowered, and to be on the safe side regardless, make sure your audio sampling rates all match at the Operating System level (your OBS Studio log will list your audio devices and their sampling rate). Mis-matched sampling rates, especially on under-powered PCs, have previously been reported to contribute to shifting sync, which is really bad as a single delay adjustment won't suffice.. literally the delay can vary over the course of a session.

if I recall correctly, an issue you may have is that the OBS Studio - Audio Monitor is before filters and effects... so can make real-time monitoring a challenge. For that reason, if audio quality is that important and/or your audio sensitivity is that high, what you will come across (from Aaron and others) is to process audio outside OBS Studio (in this case, including audio delay) and only send the fully processed audio to OBS Studio.
 
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Nickl23

New Member
Hello,
Thank you both for your replies. I should have been more specific in my initial statement. Firstly, yes, I am using my studio Audio (Lynx Aurora 16 AES). The problem, however, is not that the video and audio are out of sync. As I stated in my original post, they seem perfectly synced but the lag is certainly more than 1/4 second. I would put it at about1 - 1.5 seconds which is intolerable. So I guess what I'm asking is: Is real time monitoring possible in this environment? With the audio in my studio I use a signal splitter for the vocal mic so I can monitor off a board (perfectly in real time) while the recording signal has about a 200 - 300 ms lag. I can't hear it so it doesn't bother me. Is it really the case that NO-ONE who is producing YouTube videos is able to monitor their performance while creating? Thanks again.
 
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AaronD

Active Member
I think 1/4-second is workable as a self-monitor, once you get used to it. And my rig *is* that fast, once I figured out the glitch that I mentioned before.

I've also seen people record their rigs as tutorials, and they happen to catch several generations of a loop in the same shot. You of course get the "Twilight Zone" effect from that, but it's fast enough, on Windows, that the first one or maybe even two generations could easily be used as a self-monitor.

How to guarantee that though, I don't know, except to use a low-latency Linux kernel like Ubuntu Studio has, already installed and working out of the box. As far as I can tell, I think the good Windows rigs just got lucky. Or maybe they followed the Windoze philosophy of needing a ton of everything to do anything, so that the bloat doesn't matter so much.
 
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Lawrence_SoCal

Active Member
Nickl23 said:
Hello,
The problem, however, is not that the video and audio are out of sync. As I stated in my original post, they seem perfectly synced but the lag is certainly more than 1/4 second. I would put it at about1 - 1.5 seconds which is intolerable.
Click to expand...
To clarify - are you saying the video is 1.0 to 1.5 seconds behind the audio? if yes, then I'd look to your Operating System and OBS Studio settings to avoid excessive processing delays. What settings? it depends... sorry
Per the pinned post in this forum, if you post your OBS Studio log, we can check OBS Studio logs for obvious items (better yet, use the Log Analyzer to check your settings up front).. links to all of these in my .sig
However, that won't tell us what you have going on at the Operating System level that may be slowing things down.
Or maybe something like using cheap, slow, varying latency security cameras using RTSP?
 
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