Resoultion Downscale For 2560x1440 Monitors?.

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BlockAboots

Member
My monitors native res is 2560x1440, and i would like to use the 'resolution downscale' option in the video settings of OBS to downscale to 1080p for Youtube, but have noticed that there is no 1080p resolution available, only 1280x720 or the nearest to 1080p is, 2048x1152.

Is it possible to add a 1080p option for people who have monitors that have a native res of 2560x1440??
 
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BlockAboots

Member
Yeah i understand that, but for quality purposes i always thought it was best to use the resolution downgrade option?

It does seem strange that it has a 720p res but not 1080p!?
 
paibox

paibox

heros in an halfshel
The reason there is no 1080p downscale is because there's no 1.333 downscale shader (2560x1440 is a slightly problematic resolution). Jim has added new downscale shaders before, but I personally have no idea if 1.333 is actually possible to do.
 
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Lain

Forum Admin
Lain
Forum Moderator
Developer
It is actually now possible with recent code to specify a custom downscale size, even of different aspect ratios. I'll see what I can do about it in the future.
 
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leetminiwheat

New Member
Hello, sorry for the bump but I hope this feature request wasn't forgotten about! I currently have to record in 2048x1152/ultrafast in order to get 1080p for YouTube.

Or alternatively if you could please explain where in the code this might be changed to add a new custom downscale resolution I'd appreciate it, Thanks.
 
Boildown

Boildown

Active Member
If you're going to upload to YouTube later, why do you need to downscale in the first place? You can upload 1440p to YouTube.

This is not meant to diminish the need for a 4/3rds downscale, by the way.
 
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leetminiwheat

New Member
Boildown said:
If you're going to upload to YouTube later, why do you need to downscale in the first place? You can upload 1440p to YouTube.

This is not meant to diminish the need for a 4/3rds downscale, by the way.
Click to expand...

Too much fps lag to record at 1440p, even with ultrafast.


I don't see how hard it would be to discard 1 out of every 4 pixels since 1080 is 0.75 of 1440. Where does this 1.33 come from? (Edit: Nevermind, it appears to be a backwards multiplication ratio. I still find this odd since we're stepping down not up?!?)
 
Boildown

Boildown

Active Member
It is confusing, because I have to tell people to use a larger downscale to make their stream resolution smaller.
 
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kaellar

New Member
I'm actually interested if downscaling the resolution from 1440p will even work with hardware encoders like QuickSync or NVENC. Their specs say 1080p is maximum, so the question is at what step does the hardware encoder comes in - before the downscaling or after that?
 
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leetminiwheat

New Member
kaellar said:
I'm actually interested if downscaling the resolution from 1440p will even work with hardware encoders like QuickSync or NVENC. Their specs say 1080p is maximum, so the question is at what step does the hardware encoder comes in - before the downscaling or after that?
Click to expand...

I just tested NVENC on my GTX 690 and it records fine at 1440p@30fps/High Quality. It struggles to keep up at 60fps though without dropping quality down to High Performance. So... while they may only "officially" support 1080, beefier GPU's obviously can handle higher.

Edit: According to Nvidia, NVENC supports "Up to 4096x4096 encode" (page 27 here: http://www.geforce.com/Active/en_US/en_ ... -FINAL.pdf )

Edit2: But it appears Shadowplay only supports up to 1080, and OBS+NVENC is too unstable above 1080, leaving 960p as the only option.
 
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leetminiwheat

New Member
I also tested Intel QuickSync which *is* limited to 1920x1080 or 1920x1200. So, we *really* do need a downscale to 1080 because the next best we can do with QuickSync is 1.50 (1706x960).

So, between NVENC being unstable above 1080p and QuickSync having a 1920x1200 limit people with a 1440p monitor are pretty f*cked right now.

Edit: sorry to bump, meant to edit above post with this.
 
paibox

paibox

heros in an halfshel
It will not be implemented. As Jim already pointed out, it's not possible to do with the shader code in the current version of OBS. Custom downscale methods could be added in the rewrite that is currently being worked on, but it's not of high priority.
 
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