Question / Help Suggested settings to reduce 1080p 60fps pixelation

[Achilles]

Looking for some suggestions on what settings I could check out or revise.
Currently running 1080p 60fps at 8k bitrate, which seems to be the max Twitch will allow.
Only problem is during FPS games, turning will cause some noticeable pixelation at times.
I didn't know if there were any important settings I should be aware of to focus on this.
Just switched to the NVENC encoder (new) with Look-ahead and Psycho Visual enabled but I can't tell if it made a difference. GPU is a 2080.
Thing is, I've seen streams and there is virtually NO pixelation and it's the same game - so curious to know what differences I could be looking into.
Before you ask, they wouldn't tell me their settings so that isn't an option.

CURRENT SETUP:
Bitrate - 8k
Keyframe - 0
Preset - Max Quality
Profile - high
Look-ahead/Psycho enabled
GPU 0
Max B-frames 2
Resolution - 1080p
Downscale - Lanczos
FPS - 60
Color space - 709
Color range - Full

 

[Deleted member 121471]

8k bitrate is not enough to capture very high motion games at 1080p@60FPS without pixelation, though you can minimize it.

Without a logfile of a streaming session and based on your post, change the following settings:

1) Keyframe interval to 2, as it is a twitch requirement;
2) Disable "Lookahead";
3) Downscale filter is a toss up between Bicubic (consistent) and Lanczos(better but sometimes overly sharp);
4) Colour range set to partial, for compatibility reasons and to free up around 15% bitrate.

 

[Achilles]

8k bitrate is not enough to capture very high motion games at 1080p@60FPS without pixelation, though you can minimize it.

1) Keyframe interval to 2, as it is a twitch requirement;
4) Colour range set to partial, for compatibility reasons and to free up around 15% bitrate.

I figured 8k was too low but apparently Twitch caps it off so there isn't much I can do there.
Will change keyframe.
Regarding the color range, I'm guessing that 15% bitrate boost would then help with the pixelation since it can be reallocated? Would you stick with 709 still? I thought full color range would help with quality.

 

[Deleted member 121471]

Regarding the color range, I'm guessing that 15% bitrate boost would then help with the pixelation? Would you stick with 709 still? I thought full color range would help with quality.

It will help a bit with image quality in motion.

Don't touch colour space, 709 is recommended.

Browsers expect 16-235 colour range, which is what OBS "Partial" clamps the encoding to. If you select "Full", 0-16 becomes 0 and 235-255 becomes 255 so the overall image will be darker, less detailed and colour shifted.

 

[Achilles]

It will help a bit with image quality in motion.

Browsers expect 16-235 colour range, which is what OBS "Partial" clamps the encoding to. If you select "Full", 0-16 becomes 0 and 235-255 becomes 255 so the overall image will be darker, less detailed and colour shifted.

Gotcha. I forgot to ask, why should I disable Look Ahead? I'll admit I'm not fully versed in the function but it sounded like it may help.

 

[Deleted member 121471]

Gotcha. I forgot to ask, why should I disable Look Ahead? I'll admit I'm not fully versed in the function but it sounded like it may help.

Lookahead is better for low motion games and even then, it's arguably necessary. It is my understanding that it changes the number of b-frames dynamically but high motion scenes change too fast and b-frames are expensive in terms of bitrate. Think better image quality until something moves too fast.

The preset chosen (Max Quality vs Quality) and Psycho Visual Tuning are the settings that actually help quite a bit but can overload your encoder in some circumstances.

If you read other similar topics, the general recommendation is to use "Quality" preset and disable the other 2 options, for the sake of brevity since most people won't bother spending time with test recordings on a per-game basis and is a solution to most "encoder overloaded" topics.

One compromise you could try is downscaling your video to 1600x900 resolution, which will give you a tiny bit of blur but you'll have a lot more bitrate per pixel to spare.

 

[Achilles]

I think I should be okay using Max Quality since the computer is very powerful, I will definitely remove Look Ahead though. Hopefully shifting the bitrate shifting to others things will help matters. Will report back!

 

[Achilles]

Update - quality seemed better after making the changes.

There is still some pixelation which confuses me because a particular stream I watch uses the same bitrate and it is noticeably smoother. Just not sure on what the differences could be.
What is better for quality, x264 or NVENC (new)?

 

[Deleted member 121471]

Your graphic card's hardware encoder rivals x264 somewhere between "fast" and "medium" CPU preset with significantly less performance hit so there's no reason to use x264 unless you want to record and stream at the same time, at different encoding settings.

The choice between hardware vs x264 encoding, with each having their own pros and cons, ended with the release of the NVIDIA GTX 1660 and RTX 20xx series, for the vast majority of scenarios.