Question / Help Bad Video Quality / Artifacts with NVENC/Win8.1 64bit

F

fellpower

New Member
Hey

Im using 0.14.2 Studio and i have massive Artifacts in my NVENC encoded / recorded Video.

If im using X.264 with CBR / VBR, i have no artifacts.

My Core System is:

- I7-6700K
- 16GB DDR4 Ram
- SSD and HDD as Video Space
- nVidia GTX980Ti Graphiccard

Newest Driver of all my components.


I can record with 50Mbit with the X.264 Codec with CBR / VBR - without any loss of frames, but if i choose NVENC with CQP (18-23 preset), i have always artifacts in my recorded Video.

So, whats happen with it?

MY actual log is this: https://gist.github.com/952504644b412c5128ed319e88205d7a

I will get another log now, with NVENC activated, maybe it helps more, than my actual log. cant see any problems, but, some files are missing. dont know, if there used for NVENC.

greets
Chris
 
Mroczny_Gustaw

Mroczny_Gustaw

Member
what exactly do you consider artifact? little stutters which are common with nvenc or grass quality? if its grass then its normal. areas like grass and fog are hardest for encoder to process, not only nvenc. try CQP mode with values from 15 to 23 - lower better, cbr is worst possible rate control for recording
 
F

fellpower

New Member
This is nice, if i look to my uploaded Video, what i shown you, the artifacts are canceld out by Youtube with a blck Screen. So u cant see that...




I can record a top Quality, without any artifacts, video with x.264 - WITH Gras. So its not the Problem of the Gras - or the Game / Encoder.

The Problem is, IF i use NVENC i have massive Graphic Problems in the recorded Video. (As shown)

I know all these settings, because i recorded hundreds of videos with X.264. (And did many tests to get the best Quality / Size for me)

Now, i thought, it would be nice for my Cpu, if i choose my Gpu, with NVENC. But the Quality is bad as hell.

I tried all, simple, advanced, all setups, many bitrates and CQP settings. I can only record a nice Video, if i choose x.264.

My GPU Driver is the newest - and i tried that on a complete new installed WIndows 8.1 System with only OBS installed. Same thing, NVENC Videos are crappy, blurry, full of artifacts.
 
V

VanDuits

Member
If i look in your logfile you are trying to compare x264/50Mbit vs. NVEnc/30Mbit. This doesn´t make any sense.
x264 is the most efficiently lossy encoder in OBS. You have to almost double the bitrate to achieve the same quality with NVEnc.
I´m using the NVEnc aswell without any problems you are mentioning.
Don´t leave the level setting on auto. set it to 5 or higher to get better peak bitrates if needed
 
Last edited:
V

VanDuits

Member
like I said "almost".
as far as I know NVEnc is around about equal to Quicksync and if you look here
http://www.compression.ru/video/codec_comparison/h264_2012/ , then I am not so "very" wrong.
You may don´t see any differences at a bitrate of 50Mbit/s with x264/NVEnc on a game like Pro Evolution Soccer, but on more complicated material like DayZ with lots of detailed grasses you will definitely see artefacts and blurriness with NVEnc.
It depends on the game, which means the only one who is generalizing here - is you.
 
F

fellpower

New Member
If i have to double my Bitrate - for the same Quality, i can use X.264 instead....My CPU have enough Power, to do this, but i hope, that i can save a small amount of Cpu Load with NVENC.

I hope, that the NVENC have better Quality, smaller Filesize and lower CPU Load - but, that seems not to be true.
 
NalaNosivad

NalaNosivad

Member
You'll save an ABSURD amount of CPU using NVENC. Just use NVENC, and use CQP. x264 considers a value of 18 to be visually lossless.

Quite how that maps to other encoders' implementations of CRF/CQP I don't know, but I personally use a CQP of 16 with NVENC because I sometimes pull stills out of the video, and for that, I want a little better than just "this looks perfect if watching at its native resolution".
 
You must log in or register to reply here.
Top