Question / Help Settings advices + red color problem

phaolo

phaolo

Member
Hi, I'd like to record (not stream) my gameplay, but I'm not sure about the settings, can you give me some advice?

Also, I noticed some problems with the colors, expecially the red.
It's reproduced quite badly: all smeared, blocky and with bad contrast.
It reminds me of the old jpeg encoders' red bug..

pc specs
- cpu: i5 6600k (4 cores, no hyperthreading)
- ram: 16Gb
- Win7 Pro x64

video
- resolution: 1080p (same of the primary monitor)
- fps: 30 (60 could maybe require too much space and cpu)
- container: mkv
- decoder: x264
- CRF: 21 (23 looks a bit crap, 22 ok-ish, 20 used 250Mb for 7mins.. maybe too much)
- keyframe: 2 (better for seeking or cutting the video. I'd use 1, but maybe it would increase the size a lot?)
- preset: high
- profile: veryfast (I didn't notice a big difference in quality with faster, except for 15% more cpu usage)
- tune: none
- x264 options: none (I can't really find a consensus on what is good)

- renderer: Direct3d11
- color: NV12
- YUV space: 709 (I think VLC fixed it. Btw, the red is as crap as with 601)
- YUV range: partial ("full" has less washed out colors, but it looks also darker)

audio
- samplerate: 48khz (unnecessary?)
- channels: stereo (if I choose 5.1, what will happen to stereo sources?)
- bitrate 160 (good enough?)

Would 10bit improve the colors? Where can I set it?
Is x265 completely out of the question? The file sizes are incredible..
 
phaolo

phaolo

Member
Color Range test chart

These 2 files seem the most similar for my resolution and setup:
- 1920x1080_420_709_pc_10sec+10sec.mp4
- 1920x1080_color_range_test_chart.png

- my recording suffers a bit in the greys area, but for the rest it seems good enough, I think.

Color Space+Subsampling test chart

The videos in the folder seem identical to the previous test.. mistake?

Anyway, comparing this..
- 1920x1080_chroma_subsampling_test_chart.png

..to my recording, the differences are:
- the colored text suffers the previously-mentioned problem (red, but also purple and green).
- the 4:4:4 purple checkmark on the left disappears.
- the 4:2:2 check looks grey instead of white (but both not green as in the reference).
- the 4:1:1 seems ok (but both not light-blue as in the ref).
- the 4:2:0 check looks blue instead of purple (but both without a white background as in the ref).
- the green bars in the "detail lost test" aren't visible.
- the circle in the upper-right corner is slightly different (less white inside).
- the upper part of the "Encoding Matrix coefficients.." is red+green instead of gray

^ how do interpret these results? O_o
(I've uploaded my files)
 

Attachments

  • test obs colors 1.zip
    88.3 KB · Views: 96
  • test obs colors 2.zip
    128.4 KB · Views: 49
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phaolo

phaolo

Member
- About 10bit: is it worth waiting for this? Will it be implemented in the next version?
- About HEVC: I have a GTX 1070, do you think it's powerful enough for both gaming and encoding in x265? How could I test it?
- About stereo: why is it a wise choice? Do you mean the settings?
 
Suslik V

Suslik V

Active Member
Both files are OK. You can upload your videos to YouTube if you wish.

10-bits - require new hardware and new math. Let's say, not this year...
HEVC - I don't have required hardware to test it, maybe @koala knows more (he did some tests for x264 at GTX cards and maybe he can test HEVC with latest drivers, who knows...). Maybe custom ffmpeg output with single audio track needed to test the encoder.

Stereo has good compatibility. Multi-channel require much more bandwidth (bitrate) for the same quality. Multi-channel implementation were discussed a lot and still has open questions, I cannot recommend it for production. Also, check your Default Format for shared mode for the playback/recording devices in Windows.
 
phaolo

phaolo

Member
Thank you.
So, there isn't much to do about the crappy red? Would a higher CRF even fix that?
It's strange, because I never noticed such problem in YT videos by other people.

EDIT: about the 10bit, I read that my new monitor doesn't support it, so nevermind..
 
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Suslik V

Suslik V

Active Member
It is not so bad. The test charts is synthesized images (they has special patterns) and live videos always looks a way better.
Only color subsampling of 4:4:4 can improve the colors or even lossless RGB (but no one but you, be able to see this videos in their true form during post production, your audience will watch compressed videos, so I prefer to preview the final result, the "generation loss" in post production is insignificant for moderate compression).
 
phaolo

phaolo

Member
Ah but I'm recording these videos for me, so I'm more interested in the current quality (and size).

I've tried 4:4:4 (I444 right?) and the colors became more vivid, but.. pixelated too O_o
Also, I now can see the 4:2:2 checks in the test image, instead of the 4:4:4 one. Is this expected?

Btw, are non-NV12 formats compatible with players and editors?
Also, why isn't the color setting separated for streaming and recording like the rest?
 
Suslik V

Suslik V

Active Member
Some players has internal optimizations (try to disable hw accelerated codecs) that uses 4:2:2 instead of 4:4:4, so this error is on display only, the file itself still 4:4:4, I think. Of course, this additional color info require space to store.

The settings not separated because of how all stuff rendered to output (if you need more info, please look at the pictures from OBS Studio Help Guide: https://obsproject.com/forum/resour...ware-studio-multiplatform-help-guide-pdf.365/ - Application Settings>Video section) - this has less impact on GPU (renderer) and really, color settings can't be bad or good - they can be just different (only depends on hardware you chose, and on your target device, where the final content will be viewed).

If you so badly need something special, there is custom encoder settings string named x264 Options (separated by space) for software x264 encoder.
 
phaolo

phaolo

Member
Disabling "Use hardware YUV->RGB conversion" was indeed a solution for 4:4:4 ! (maybe I should report this to VLC?).
Now I can see its checkmark in the test pic and the colors are way better.
However, I can also see the "Bt.601 matrix over Bt.709 source" check, so something isn't still right.

But.. will 4:4:4 need double the size of 4:2:0? :O

And about the "x264 Options", sadly I've no idea about what is good (e.g: is "bframe=5" worth?)
 
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Suslik V

Suslik V

Active Member
If you running VLC Player v3.0.2, then you can set Prefernces(Ctrl + P)>Video>Output: OpenGL video output for Windows - only this will help right now (Edit: Partial range videos only). (Playback videos fullscreen only, because render may place pixels in half of the real screen dots)

4:4:4 vs 4:2:0 nope. The raw uncompressed size - yes, it is:
Width x Height { for Y } * 8 + Width x Height { for U } * 8 + Width x Height { for V } * 8
vs​
Width x Height { for Y } * 8 + (Width / 2) x (Height / 2) { for U } * 8 + (Width / 2) x (Height / 2) { for V } * 8​
but then both is compressed with quality loss, so not always twice lower.

x264 Options (separated by space) - on your own risk!
 
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phaolo

phaolo

Member
Ok thanks, OpenGL is what really fixed 4:4:4.
I wonder if those problems for the "automatic" output module are caused by some bug in VLC.

Btw, I made 8 color tests with part\full 4:2:0\4:4:4 601\709 and the real quality difference seems to be the 4:4:4.
Its file size difference is already 20-25% bigger, however, compared to 4:2:0.

(p.s: the 444 + 601 clips show the warning: "Bt.709 matrix over Bt.601 source")
 
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Suslik V

Suslik V

Active Member
If you don't care, about available playback options, then you can try https://mpv.io/installation/ (I'm using old mpv-i686-20150411 it has no classic user interface and files were open by drag and drop or via explorer's right-click menu - Open with... ).

I can say that I use more than one player. And the one, I use every day, is heavily customized by myself and it uses external decoder (LAV Video Decoder v0.70.2.80-git) where I can disable all output modes but RGB, and where I can specify the output range manually.

Edit: about 601 of HD sizes - this is common behavior for the players (unfortunately). For this videos you can use VLC Player v3.0.2 (for example, portable vlc player in different folder) with DirectX (DirectDraw) video output and disable Use hardware YUV->RGB conversion as you did it before.
 
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