Question / Help Controling bitrate with custom crf vs quality dropdown

[ZeroTalent]

in XSplit, the quality setting 10 is equal to crf 25. I figured OBS would be the same. But, I noticed that when I set the custom x264 settings to crf=21, the logs say I am at quality 7.

=====Stream Start=====================================================================
  Base resolution: 1920x1080
  Output resolution: 1920x1080
------------------------------------------
Loading up D3D10...
------------------------------------------
Using auxilary audio input: Microphone (Realtek High Definition Audio)
------------------------------------------
Audio Encoding: AAC
    bitrate: 128
Using custom x264 settings: "crf=21 tune=animation bframes=16" | okay, that's good
------------------------------------------
Video Encoding: x264
    fps: 25
    width: 1920, height: 1080
    quality: 7 | hmmmmmm....
    preset: faster
    i444: no
    max bitrate: 3500
    buffer size: 10500
------------------------------------------
Total frames rendered: 2250, number of frames that lagged: 1 (0.04%) (it's okay for some frames to lag)
Number of b-frames dropped: 0, Number of p-frames dropped: 0
=====Stream End=======================================================================

Profiler results:

==============================================================
frame - [100%] [avg time: 14.256 ms] [avg calls per frame: 1] [children: 96.2%] [unaccounted: 3.84%]
| scene->Preprocess - [46.6%] [avg time: 6.645 ms] [avg calls per frame: 1]
| video encoding and uploading - [49.6%] [avg time: 7.064 ms] [avg calls per frame: 1] [children: 22%] [unaccounted: 27.5%]
| | CopyResource - [0.0421%] [avg time: 0.006 ms] [avg calls per frame: 0]
| | conversion to 4:2:0 - [11.2%] [avg time: 1.59 ms] [avg calls per frame: 0]
| | call to encoder - [10.9%] [avg time: 1.547 ms] [avg calls per frame: 0]
==============================================================

Did I do something wrong? Or are the OBS quality settings different from the XSplit settings, so crf 21 is actually quality 7?

Also I'm just curious, if I want to use bitrate & ratetol for rate control, instead of crf, how do I turn off the crf/quality entirely?

 

[sh0gunshin]

try typing in faster&ex:crf:21

 

[Staretta]

Yes, the quality settings are different than XSplits settings. I'm not sure if Jim changed the settings around at all in the last 10 days, but on IRC he mentioned OBS's Quality 10 is crf 18, and Quality 0 is crf 28.

And you're right about XSplits settings, according to Xsplit's Blog, Their quality 10 is 25, and quality 0 is 35.

So, definitely different. ;P

 

[R1CH]

try typing in faster&ex:crf:21

That's for xsplit, OBS uses a different method for custom parameters in the form of space separated key=value pairs.

 

[ZeroTalent]

Thanks for the help ... a lot of stuff will be bitrate limited for most people, but for slow-moving scenes there's still some benefit at crf 18.

Also I'm just curious, if I want to use bitrate & ratetol for rate control, instead of crf, how do I turn off the crf/quality entirely?

Any word on this part? Just for experimental purposes :D.

 

[Krazy]

try typing in faster&ex:crf:21

That's for xsplit, OBS uses a different method for custom parameters in the form of space separated key=value pairs.

Is there a list somewhere outlining all these custom parameters? I would love to tinker around with stuff

 

[Fred_]

I think you're looking for something like this. More often than not, presets are the only thing you need to fiddle with nowadays.

 

[Krazy]

Yeah, I know about all the x264 settings, I'm just asking about how to actually put them into the OBS custom parameter box since it's apparently a different method than xsplit

 

[Fred_]

It's parameter="value", like this:

vbv-maxrate="1000" vbv-bufsize="2000"

 

[Krazy]

ah, ok. thanks!