Bug Report Occasional stutter every 5-10 minutes when a webcam or media source is active

[Lapppy]

In 0.11.1, I noticed that my recordings have a very noticeable jitter/stutter every 5-10 minutes. This only seems to occur if my webcam is active (obs is using it in some way) or if another source such as an image or a video is in the scene.

This did not happen in 0.10.1.

The webcam video and the image can be toggled off but will still cause a stutter.

In my tests, the webcam was both used as a video source and as a microphone. The problem happens even if only the microphone is being used and there is no video source

Log file reports 0 dropped or skipped frames.

It could possibly be related to this bugfix, but I don't know for sure.
https://github.com/jp9000/obs-studio/commit/7f7901b9302815bda40c2cb9e5c307fb685f5364

---

Going to try some simple things like a reboot and a clean install, sometimes that can be enough to fix things...

 

[Lain]

Webcams aren't affected by that patch you linked, media source would be though. So you're saying it only happens when a webcam is active? I actually find that very interesting, and potentially a lead in my investigation. The fundamental problem still occurred in 0.10.1, but it caused memory usage to continually increase. The patch is honestly a temporary solution to a potential issue with frame caching that I'm still investigating. Thanks for the information.

 

[Lapppy]

yea... I thought that maybe the stutter was because of the cache clearing or something.

So far it seems to happen if obs is using my webcam in some way (as a source or as a microphone for example) or if there is an image in the scene. I'm still trying out different combinations, etc to see what affects it, so i'll post back later with some findings.

I've mostly been recording League of Legends, and it has caused some problems in the past with stutters but not this much. I'll try to rule out the possibility that its the game itself causing the issue.

---

EDIT: I went ahead and did a clean install of obs 0.11.1, deleted its appdata folder and reset all of the settings, rebooted for good measure, etc. and did some more tests. Since then, I've noticed a couple of things...

1. The stutter issue is almost gone! or it is not as noticeable as before. There is still a stutter every so often but not as bad.
2. The issue does not seem to happen on simple mode, only advanced mode. I had a 30 minute recording on simple mode that didn't seem to have the stutter at all, but showed up when I did a test in advanced mode. I'll try this again later to be sure...
3. Recording quality looks blurrier on simple mode and nice and sharp on advanced mode. (not as in low bitrate, it just looks blurry and scaled up slightly.)

I won't have lots of time to do more tests for a while, but from what I can tell the issue is most obvious in LoL.
I had two capture sources running at one point and when a stutter happened, frames were only missing from the LoL capture source when played back frame by frame. Frames weren't missing from the other source but they seemed to stutter a little when played back at full speed.

I also tried TF2... It wasn't the greatest test since i wasn't playing at constant 60fps but the recording didn't seem to have a stutter. it might have happened but I didn't notice it.

This could be LoL just acting really weird. Recordings of LoL have micro stutters in every version of OBS I've tried, but not always in other games. Maybe this is an issue more related to LoL or graphics drivers than OBS?
Then again, other capture programs can capture LoL perfectly fine, i've heard.

 

[Lain]

The stutter issue is specific to device/media capture, not to window/display/game capture for example. The occasional minor 'skip' issue that I was talking about that can happen for some people will only happen with the media source or with a device source.

 

[Lapppy]

Interesting... I must have a different issue then, because I have only seen stuttering in window/display/game captures.
I see micro stutters throughout the recording and every few minutes a very large stutter occurs if OBS is using a device or if other media is present. If I only use a display capture with only desktop audio, only the micro stutters occur.
I don't really care about the micro stuttering as much as the bigger stutter issue... but it is still an annoyance.
There were some other threads earlier that mentioned some of the same issues I've been having... I've read them but nothing has helped.
https://obsproject.com/forum/threads/stuttering-at-60fps-workaround-found.21525/
https://obsproject.com/forum/thread...-missed-frames-preventing-fluid-motion.21144/

I finally had some time to do another recording: Unfortunately the stutter still exists in simple mode. I must have been lucky the first time?

I have yet to do much outside of LoL, since that is what I use OBS for the most. In a couple of days I will record some other games and see if the bigger stutter is there. Micro stutters are the most obvious in LoL and usually don't show up in other games, so i'm really hoping that the bigger stutter is specific to LoL and not OBS.

 

[Lapppy]

Did some more tests recently.
One test I did was a Display capture of TF2.

1. The bigger stutter issue also happens in TF2.
2. Bigger stutter seems to only happen if Display capture is used. Normally for TF2 I would use a game capture anyways, and I don't recall seeing a bigger stutter when using game capture. I will try this again to confirm.
3. Regardless of game capture or display capture, TF2 has hardly any microstutters in its recording.
4. Game capture preforms very bad in LoL compared to display capture, for whatever reason. There is microstuttering everywhere in the recording (at points it feels like the recording is half the frame rate) but no obvious trace of a bigger stutter issue every few minutes.
5. I went back to 0.10.1 to make sure that the bigger stutter didn't happen earlier. Recorded an hour long video that did not appear to have a bigger stutter, only microstutters.

Also, this thread pretty much describes my microstutter issue, though I don't recall VFR fixing it in the original OBS.

 

[Lain]

for #5, I didn't change anything with game capture between 0.10.1 and 0.11.1 other than added a fix for win 10 (which is completely unrelated and wouldn't even get called if you're not on win 10)

 

[Lapppy]

Interesting, though I believe I did that test with a display capture since I know that game capture doesn't appear to have the bigger stutter. (haven't confirmed that yet, soon though...)

Recently I've been trying to build OBS-MP from the source code but as someone who isn't a developer it is too confusing and difficult with the little documentation that there currently is. The idea was that I could figure out what change caused the issue to occur in the first place by building older versions of OBS-MP between 0.10.1 -> 0.11.1 and testing those for the bigger stutter...