Question / Help Help with Blurred Stream

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Matt Mendoza

New Member
Hi,
I'm new to streaming and we stream our live, in-store events. The first couple times we streamed, everything went great. Now, for the past five streams, I have this motion blur that I can't shake. Example: http://www.twitch.tv/ogresgames/b/528606800

It's very frustrating because it didn't do this before. I've fiddled with everything I can think of. We're currently hard-wired into our router. I run the stream from a Mac with Windows 7. The camera we use is a Logitech C920 and the blur even exists in the stream preview. Here is the latest log file: https://gist.github.com/815245c284d554c3a5ba

I am at a loss as what to do to fix it. Does anyone have any experience with this problem?

Thanks!
Matt
 
FerretBomb

FerretBomb

Active Member
First, drop to 30fps. You absolutely do not need 60fps for that setup. I assume you raised the framerate to try to fix the blur. Instead it's causing the encoder to choke, especially on lower bitrates, with that i5.

Second, you need to open up the c920 crossbar/options and DISABLE ALL AUTO-SETTINGS. Seriously, turn off the auto-focus, Rightsound, follow my face, and all of the stuff in the Advanced Settings too... gain, white balance, all of it. Adjust manually. DEFINITELY turn off RightLight.

Third, the blur is happening either due to the auto-adjusts you just turned off (probably the gain adjustment), or due to there not being enough light. If your gain on the Advanced tab of the camera settings program isn't almost all the way to the left, and Exposure isn't near the middle, you may need to add more lights to your area. Here's a screenshot of my camera Advanced settings, for comparison: http://imgur.com/kpSkPRW

Fourth, and this is less likely as you're running the cam in 720p mode, you might have other stuff on that USB host controller that's choking the camera. Go into the Device Manager and switch to 'view devices by connection' then drill down to find the USB section, and make sure the camera is the only thing on its USB Host Controller. Normally you only really need to do this one if you're running in 1080p mode.

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Short version, each frame needs a certain amount of light to register. Not enough light? It can try to amp it internally (which can cause fun issues) or it can just 'hold the shutter open' longer. Problem is, the longer it holds the shutter, the more motion blur you get, and the fewer frames that can be captured in a given second on top of that. So with half the light it needs available for an optimal picture, it'll run at half the framerate (roughly) to try and compensate. And you end up with what you are seeing there.
 
M

Matt Mendoza

New Member
Hey Ferret, thanks for the great reply! I forgot to mention that I put all of my settings, excluding Auto White Balance, to manual as soon as I could. I'm actually very experienced with film and photography, so having control over that was a huge first concern (I also hate digital gain, so I use as little of it as possible). Second, I'm worried then that I screwed up the cam somehow. I put an ND filter over the lens to help with glare and opened the shutter about 4/5's of the way to compensate (our building's light changes as night falls, so I have to adjust). I'm worried it might have gotten stuck that way? Or something?

I got a second cam and added it to the set up. It immediately looked much better than the first camera. No real motion blur to speak of and I could not tell what was different in the settings. They're identical models and they appeared to be set up identically. Then, later, when I was trying to control them separately, I couldn't adjust anything on the old one, and when I tried, it actually adjusted the settings of the new one. Like, I could toggle between them (Logitech C920 and Logitech C920 (2) in the Device Selection window, and I could put them both on screen and they would register independent images, but when I went to the Advanced Settings screen to adjust the Brightness, for example, it would only adjust the brightness of the new camera. My temporary solution was to replace the existing overhead camera with the new one and use the uncontrollable old one as-is. I unplugged each camera, removed them as video sources, restarted OBS and my computer, and I still was not able to control the old camera. Is this a common issue with multiple cam set-ups when they're the same model?

Here is my latest log file: https://gist.github.com/590ba708f2bd7d99a77d

Here is my latest broadcast for comparison: http://www.twitch.tv/ogresgames/b/528916529

In terms of quality, it's a marked improvement, but I would like to incorporate the second camera and it's not working. I'll also experiment with light levels to see if that helps.

Thanks!
 
M

Matt Mendoza

New Member
And my exposure is only a notch or two higher than the one you have in your picture. Is that in the "safe zone" for this camera?
 
FerretBomb

FerretBomb

Active Member
That may be an issue with the Logitech drivers themselves; I assume you're using the latest ones only, and not any that were packed in with the device? Can't remember if they bundled any, or just said 'go to our website and download them already'.

Yeah, OBS doesn't address the cameras directly when you use the 'configure' button, it just calls the config software and assumes that it's well-written. If Logitech's software isn't able to handle adjusting multiple cameras or differentiating between two, that's Logi's problem. I'd recommend hitting up Google about that one, or contacting Logitech support about it. Don't even mention OBS, just that the configuration software isn't working with multiple cameras of the same model plugged in, and one is behaving erratically. Have you tried unplugging the second cam, switching on the auto-settings on the problem child, hitting OK/saving the settings, starting the cam, stopping the cam, and then switching the autos off again? It might be stupid, but I've noticed that these cams seem to have internal logic that can get 'stuck' on rare occasions. Only happened to me once, and a manual reset to defaults knocked it loose.

Not sure what you mean by opening the shutter in this context... increasing the exposure I assume? Again, longer exposure = lower framerate. Only thought would be if the ND is tweaking with it somehow; have you tried removing it again to see if it'd stop misbehaving?
 
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