Nvidia background blur filter breaks when changing source settings

[nacalai]

Operating System Info

Windows 11

Other OS

No response

OBS Studio Version

31.0.0-beta1

OBS Studio Version (Other)

No response

OBS Studio Log URL

https://obsproject.com/logs/jGTLU5KA1yTTcMXH

OBS Studio Crash Log URL

No response

Expected Behavior

One would expect the nvidia background blur filter to work when changing source settings

Current Behavior

When changing source settings, the background blur filter produces a black output when the value is above 0.

• It happens on any change, on any source.
• It is limited to the source itself. The filter on other sources are unaffected, until you change its source settings.
• Completely deleting the source, adding a new source of the same type (image, video device, etc), adding the filter, does not fix it. It still produces black. However, you can add the filter to existing sources of the same type, and it will work.
• Restarting OBS seems to be the only way to fix it.

The log indicates something is going wrong:

18:38:25.817: [DShow Device: 'Video Capture Device'] settings updated: 
18:38:25.817:   video device: Mevo-2BNJ2
18:38:25.817:   video path: \\?\usb#vid_046d&pid_d119&mi_00#7&175b2019&0&0000#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\global
18:38:25.817:   resolution: 1280x720
18:38:25.817:   flip: 0
18:38:25.817:   fps: 30.00 (interval: 333333)
18:38:25.817:   format: MJPEG
18:38:25.817:   buffering: disabled
18:38:25.817:   hardware decode: disabled
18:38:26.353: [NVIDIA Video Effect: 'NVIDIA Background Blur Filter'] Error running the BLUR FX; error -9: The specified pixel format is not accommodated

Steps to Reproduce

1. Add a source
2. Add the nvidia background blur filter to it
3. Change any setting on the video capture source
4. The filter will produce black output
5. Restarting OBS will fix the problem. ...

Anything else we should know?

So far I've only tried it on an image source and a video device capture

No response

[nacalai]

Just discovered that it happens even if you open source settings and just hit 'Cancel' with no change. It will produce black. However, hitting 'Ok' is fine. Weird stuff :P

[pkviet]

thanks for the report, gonna check this

[pkviet]

i was able to confirm. Thanks

[pkviet]

i am suspecting an sdk underlying issue where reloading of the FX gets stuck. Not sure it can be fixed on our side. I'll discuss this with our nvidia contacts. There's no such issue with greenscreen effect which makes me suspect the blur sdk since the code seems ok.

[nacalai]

Thanks for looking into it.

Quick one: is 0.05 the lowest amount of blur one could have? The blur at 0.05 is too much for my use case. I just want a really subtle blur

[pkviet]

Thanks for looking into it.

Quick one: is 0.05 the lowest amount of blur one could have? The blur at 0.05 is too much for my use case. I just want a really subtle blur

I've set it at 0.05 steps indeed. I could lower it to 0.01. I'll do some tests first.

[pkviet]

Bug filed with NVIDIA.