Pixel Format wrong / Poor quality output.

[YellowOnion]

According to another issue, this driver just copies the data "as-is", Since OBS uses NV12 by default, I wonder why VLC refuses to play another with anything other than YUY2, and I assume because the pixel format is incorrect, the quality is god awful?

[CatxFish]

There's format/resolution converter in virtual source to convert format to YUY2 , so it's not actually "as-is".
But I don't think that is your problem, you probably don't get the resolution right on VLC . Try ctrl+I in VLC to see the video resolution in the media information.

[YellowOnion]

Both are 1280x720, If I move the image 1 pixel to the left or right the vertical bar on the cross appears:

The image shape doesn't radically change if I move the image up or down like this.

[CatxFish]

The architecture flow is like this :
RGB32(OBS GPU display/preview kernel) -> NV12 (OBS output module) -> YUY2 (VLC),

So the output quality is actually lower than display , that's true. In most circumstance it's hardly to distinguish unless you use a thin line or small fonts.

Maybe you want to ask why to convert the format to YUY2 ? It's because YUY2 has better compatibility for 3rd party software.

In fact I am not sure which conversion cause the quality loss most, you can change the output format to RGB32, If the line is still disappearing , then the loss is occurring on the virtual camera side. Otherwise , it is occurring on the OBS output module.

I will consider if it's necessary to make modification on this because the modification might cause more CPU/memory usage.

[YellowOnion]

The T bar, and cross bar shouldn't disappear though, they should just be blurrier, this looks like nearest neighbor scaling.

Having a look at the source code, you're using SWS_FAST_BILINEAR to convert perhaps it's that.

I'll have a look at compiling it with SWS_BILINEAR see if that helps.

[YellowOnion]

Okay, so the plot thickens, I opened up the dshow device with ffplay and the output looks fine, it also plays at the correct fps (60) instead of 30, I wonder if VLC is just doing something funky.

[CatxFish]

Hmm... Since you mention the fps is not correct. Is it possible related to the deinterlace setting in VLC?

Although it's maybe not the answer of your problem , I might change the output module format to YUY2 if I confirm it will not increase CPU usage.

[Davigugu55]

on VLC the image looks as previously commented, same on Microsoft Teams (guess same will happen on Skype). The thing is that it works as expected on Chrome, so if I use any website that can get the virtual cam output it works fine via browser. Hope this helps on something.

Update: actually it is unusable on MS Teams even on browser, but on https://webcamtests.com/ it works as expected.

[MrSpock777]

Same situation here! Tried on 3 different machines.
Win7 + Win 10 / AMD and Nvidia

But it happens also by using NDI or other Software. Output is unusable.
I am now setting up some Ubuntu to check if it happen there to.

Only Result i had, is by adding a codec Pack... now if i force 16:9 in VLC, the picture is "OK"

It has to be something with H.264 and Rendering i think....