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Topic: Banding when SVP activates

First, thanks for your awesome software! It’s really great.

For some reason, I recently experience banding whenever SVP is active. My configuration is PotPlayer+LAVFilters+MadVR+SVP. Everything except SVP is downloaded from imouto.my/redirect/32.

I did not notice this banding problem before; it happened without me changing something in the SVP settings. I do use other programs that use Avisynth, though (AvsPmod and MeGUI), maybe those have something to do with it?

Anyway, when watching 8-bit anime, this is how it looks like when starting the file (during the delay before SVP activates):
http://i.imgur.com/PHVM6xZ.png

And this is after SVP activates:
http://i.imgur.com/dJ5ccEB.png

MadVR info display (Ctrl+J) always says 8-bit NV12.

Can anybody tell me what I have to do to get rid of the banding?

2 Reply by Nintendo Maniac 64 (edited by Nintendo Maniac 64 14-03-2015 02:48:24)

Re: Banding when SVP activates

Well first off, are you sure those are the exact same frames?  Because the position of the eye doesn't quite line up 100% (it's off by literally a couple pixels).

Other than that, I personally can't really help you since it can't be what I initially assumed since you specifically said it's an 8bit clip.

  • MAG79
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Re: Banding when SVP activates

Kadano
SVP can process 8bit YV12 only. NV12 can be converted from/to YV12 without losses.
Do you use OpenCL acceleration in SVP (SVP-Manager tray icon - GPU-acceleration)? It works more precize with colors and must help to avoid banding.

If your video 10bit depth then I recomend to use dithering in LAV Filters to convert video to 8bit with high quality and without visible banding artifacts.

http://www.svp-team.com/forum/misc.php?item=3385

I use these settings to watch 10bit movies with SVP.

Post's attachments

LAVFilters_dithering_to_8bit.png, 46.78 kb, 638 x 519
LAVFilters_dithering_to_8bit.png 46.78 kb, 374 downloads since 2015-03-14 

4 Reply by Nintendo Maniac 64 (edited by Nintendo Maniac 64 14-03-2015 07:21:45)

Re: Banding when SVP activates

Wait, SVP can't handle 4:4:4 chroma as the input?  I thought it was able to do so...

EDIT: Just tested it using this chroma test pattern and sure enough SVP cannot.  Huh, not sure why I thought otherwise...


Is it at least able to output at 4:4:4 chroma, like when downsizing a 1080p video to a 768p screen?

EDIT 2: It would seem that SVP does indeed process (or at least resize) and output at 4:4:4 chroma.

  • Thanks: 1

Re: Banding when SVP activates

Nintendo Maniac 64
These are not the exact same frames, yes. Because SVP is inactive initially when skipping to a bookmarked timestamp, it was hard for me to capture a frame both with SVP active and without. But I can confidently say after testing several times that the color banding is always apparent when SVP is active, and not there when SVP is off. (For example when opening another instance of PotPlayer and opening the same file, or setting Quick Settings → frame interpolation mode to Off.)

Also, where would you get 4:4:4 content from? I’d love it if it was standard, but unfortunately almost everything is in 4:2:0 even.

MAG79
Video and monitor are 8bit, so I suppose even if I had 10bit video the monitor would display it as 8bit?

But anyway, I have all my settings like you instructed (GPU-acceleration / OpenCL checked, random dithering, output formats only NV12 and YV12) and the banding is still there as soon as SVP activates.

6 Reply by Nintendo Maniac 64 (edited by Nintendo Maniac 64 15-03-2015 01:19:29)

Re: Banding when SVP activates

Kadano wrote:

Also, where would you get 4:4:4 content from? I’d love it if it was standard, but unfortunately almost everything is in 4:2:0 even.

I made my own using said test image.

EDIT:

Kadano wrote:

Because SVP is inactive initially when skipping to a bookmarked timestamp, it was hard for me to capture a frame both with SVP active and without.

I find that I can navigate frame-by-frame in MPC-HC with SVP activated... (I realize that you're using PotPlayer instead).

  • Thanks: 37

Re: Banding when SVP activates

Kadano
Press F when playing with PotPlayer to move frame-by-frame. With MPC-HC, I think it's arrow left/right.

Apart from that, I can't find that strong banding when SVP is activated,
or maybe there's difference and I just fail to notice it.
I'm setting the ffdshow output to PO10 instead of auto, not sure if this affects somehow.

Re: Banding when SVP activates

mashingan wrote:

I think it's arrow left/right

It's actually Ctrl + left/right arrow; just left/right arrow skip forward or backwards by 5 seconds.

  • Thanks: 37

Re: Banding when SVP activates

Nintendo Maniac 64 wrote:

It's actually Ctrl + left/right arrow; just left/right arrow skip forward or backwards by 5 seconds.

That's actually shortcut key for MPC-BE in my system. And the reverse (just like I posted) for MPC-HC.

But one can set it to whichever he/she likes.

  • Thanks: 1

Re: Banding when SVP activates

mashingan
Setting ffdshow video decoder (raw) output to PO10 did not improve anything for me.

I find it hard to find the exact same frames in SVP and non-SVP mode because of the interpolation frames in-between. The difference is consistent, though. The banding in SVP is always apparent, and without SVP it’s never there.
This is the closest I managed to get:
http://screenshotcomparison.com/comparison/116233

Also, I don’t think ffdshow is at fault here. When I set SVP frame interpolation mode to Off and re-open the video, without changing anything else, the banding is gone.

  • Thanks: 37

Re: Banding when SVP activates

Whoa, that's really severe banding artifacts.

As far I can see, the banding artifacts from original frame are interpolated too.
For any 8-bit video, I've never downloaded 1080p HS version.

It's said that 1080p from HS (or CR specifically) is never truly 1080p, cmiiw

For TV capped version, I only download 720p so that's why I've never found the strong banding when using SVP.

12 Reply by James D (edited by James D 15-03-2015 11:33:01)

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Re: Banding when SVP activates

1. turn off SVP interpolation.
2. double click on ffdshow tray icon, Levels, set force RGB conversion and adjust sliders to 16-235.
3. Right click on ffdshow tray icon and select Levels. Do you see now the same banding as you saw it with interpolation?

  • Thanks: 1

Re: Banding when SVP activates

James D
Doing that causes the picture to be dark and there is some banding, yes, but it’s hardly visible. Not quite as in-your-face as with SVP. http://i.imgur.com/FBDCpLq.png

14 Reply by James D (edited by James D 15-03-2015 11:38:15)

  • Thanks: 97

Re: Banding when SVP activates

it was worth to try.
Can you upload a sample? To cut video without quality loss you just download mkvtoolnix, launch mmg and in global settings set frame range to cut.

P.S. BTW and if you adjust range to 0-255 but still enable levels while SVP interpolation? What if convert to RGB helps?

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Re: Banding when SVP activates

I ended up upgrading my system from Windows 7 to Windows 8.1 (because of the better power management—Win7 drew 60W more in idle due to my hardware configuration), and ever since installing the PotPlayer+LAVFilters+MadVR package and SVP again, the banding problem has disappeared. Even in the anime scene I posted screenshots of, everything is fine now.