PotPlayer doesn't show correct colors, changing Color Space does not help.

[ObjectNull85]

Hi, I'm trying to get PotPlayer to show my video as I see it in After Effects - right now Potplayer displays the video slightly too bright.

I think the problem with PotPlayer is that it's not set to the correct color space.

I'm exporting a ProRes 422 HQ video from After Effects with the Rec 709 Gamma 2.4 color space:


[Attachment 57887 - Click to enlarge]

I went to the preference in PotPlayer under Video > Colorspaces and changed the YCbCr <-> RBG Conv. from ITU-R BT.601 to ITU-R BT.709 but that made no difference.


[Attachment 57885 - Click to enlarge]

...and that is the only place I could find any mention of 709.

I checked the Output Color Space dropdown but could not find Rec 709 Gamma 2.4 as an option.


[Attachment 57886 - Click to enlarge]

Any idea on how I can get PotPlayer to display my content correctly? Thanks!

[Dreamer]

If it's a HDR video, try to click the HDR button in the navigation panel.

[ObjectNull85]

No, it's not HDR so I don't think that's the problem.

[jagabo]

The YCbCr <-> RGB conv. matrix: setting is only used when Potplayer is converting YUV to RGB (or vice versa). So set the Output color space to an RGB format.

[ObjectNull85]

So, I did a little research and it looks like all versions of ProRes export YUV (ProRes 4444 can do RGB as well), so I do think Potplayer has to do a YUV to RGB conversion for my video.

Here's how Potplayer reads my export's color space.
Color Space: YUV
Color Primaries: BT.709


[Attachment 57948 - Click to enlarge]

YUV 422 Plain 10 Bit sounds like the correct color space I should have Potplayer set to for viewing ProRes 422HQ material but that didn't make a difference. In fact, I couldn't get Potplayer to display my video differently no matter what Output Color Space I had it set to (it always looked the same, slightly too bright).


[Attachment 57949 - Click to enlarge]

Is this the same for everyone else? Does changing the Output Color Space actually make a difference for you?
Thanks!

[jagabo]

So, I did a little research and it looks like all versions of ProRes export YUV (ProRes 4444 can do RGB as well), so I do think Potplayer has to do a YUV or RGB conversion for my video.

No. The player can send YUV directly to the video renderer (graphics card).

Here's how Potplayer reads my export's color space.
Color Space: YUV
Color Primaries: BT.709

YUV 422 Plain 10 Bit sounds like the correct color space I should have Potplayer set to for viewing ProRes 422HQ material but that didn't make a difference.

When Potplayer is sending YUV to the graphics card it's up to the graphics card (or the TV/monitor) to do the conversion to RGB for display. The player can pass along the correct matrix but GPU drivers often ignore it. And once they get an update the works correctly the next update will break it again.

In fact, I couldn't get Potplayer to display my video differently no matter what Output Color Space I had it set to (it always looked the same, slightly too bright).

rec.601 vs. rec709 don't have different brightness, just a color shift. Though, if you are looking at a predominantly red or green picture you might interpret it as a change in brightness (blues are effected too but as much). If you view a rec.709 video with a rec.601 conversion greens will be too bright and reds too dark. If you view a rec.601 video with a rec.709 conversion greens will be too dark, reds too bright.

Is this the same for everyone else? Does changing the Output Color Space actually make a difference for you?

On my system Potplayer (v. 1.7.18958) displays videos correctly if the colormatrix is flagged in the file, both rec.601 and rec.709. The output colorspace is set to Auto. But I checked several of the YUV and RGB options and they all rendered correctly. With all those tests the YCbCr/RGB conversion matix was set to Auto. When the renderer was set to any of the RGB options, and the conversion matrix was forced to rec.601, only rec.601 video played correctly. If the matrix was forced to rec.709 only rec 709 video played correctly. Exactly as expected.

[ObjectNull85]

Thanks for the reply Jagabo! I don't think the problem is my video card or my display because I'm using the same display for both After Effects and Potplayer - so if my video card and monitor can display things correctly in After Effects then I assume they should be capable of displaying them correctly in other programs as well.

Here's an example of the brightening:

[Attachment 57953 - Click to enlarge]

After Effects is on the left, Potplayer on the right.

To me it looks like just a brightness change, not color, but it's hard to tell.

I'm not really sure what else to test but I'll keep looking around and will let you know if I find the solution.

[poisondeathray]

What does it look like if you re-import it back into AE ?

How does it look in other players, such as MPCHC, MPV ?

[jagabo]

I don't think the problem is my video card or my display because I'm using the same display for both After Effects and Potplayer - so if my video card and monitor can display things correctly in After Effects then I assume they should be capable of displaying them correctly in other programs as well.

No, different programs may use different methods to get video to the display. For example, look in PotPlayer's Preferences -> Video -> Video Renderer. You'll see about a dozen different choices. Mine is set to auto and it picks "EVR Custom Present" when a video is played.

Here's an example of the brightening:

[Attachment 57953 - Click to enlarge]
After Effects is on the left, Potplayer on the right.

To me it looks like just a brightness change, not color, but it's hard to tell.

It's a little hard to tell because the two images are a different size and not the same frame. But I'm pretty sure it's not a rec.601 vs rec.709 problem. Potplayer's black level is elevated but the white level is the same -- so it's not a full range vs. limited range problem. What does Preferences -> Video -> Levels/Offset show? I have this:


[Attachment 57960 - Click to enlarge]

Can you upload a small sample (not reencoded) of that section of video?

[ObjectNull85]

The Video Renderer is set to Automatic like yours, so it probably picks "EVR Custom Preset" when a video is played but I'm not sure how to check that. My Levels/Offset preferences are exactly the same as yours too.

Here's a clip I exported directly from After Effects: https://forum.videohelp.com/attachment.php?attachmentid=57965&stc=1&d=1616520193

Thanks for taking a look!

[ObjectNull85]

What does it look like if you re-import it back into AE ?

How does it look in other players, such as MPCHC, MPV ?

If I import the video back into After Effects it looks great, exactly the same as it does before I export.

Here are the other players I've tried:
Windows Media Player Classic
Windows Media Player (this can't play ProRes so I tested a H.264)
MPV
VLC

All of these display the video incorrectly. WMP, WMPC, and MPV display the video exactly as PotPlayer does, too bright.

VLC has a different problem in that it adds contrast, this makes the darks closer too what I see in After Effects but it blows out the whites.

Here's an example of what VLC is doing:

[Attachment 57976 - Click to enlarge]

After Effects on the left, VLC on the right.

You can see the letters disappearing into the sun in the VLC version where in After Effects their outlines are still visible.

[poisondeathray]

Like a color management issue 2.4 vs 2.2 display gamma.

If you re-import the video into AE, but set working space to "none" (ie. disable color management) it looks like potplayer/mpc/everything else, right? (disregard VLC observations, it's buggy) . This is because all those other programs are not color managed, and assume ~2.2 sRGB display gamma

The original Rec709 spec did not specify display gamma value... but EBU Tech 3320 and ITU-R BT.1886 introduced later on specified a gamma of ~2.4 for 709 (it's approximately "2.4", it's a non linear curve)

But the majority of computer programs use sRGB, 2.2 display gamma . This includes things like common video players, youtube, etc - which are not color managed. Professional programs tend to use the BT.1886 recommendation now by default (709, 2.4 gamma), including Resolve. You'd have to set up color management on potplayer to use BT.1866 or ~2.4 display gamma

(A 2.4 gamma appears "darker" because it's actually the inverse curve ~ 1/2.4 that is applied)

There are ways to emulate BT.1866 transfer function in vapoursynth, but I don't see the it in ffmpeg filters, otherwise you could use built in libavfilters in mpv . It kind of sucks to have to player a video using a script

The other option is to go old skool and use sRGB for everything until final format (instead of 2.4 working space) . That type of workflow will more closely emulate what you get in video players, youtube etc...

[jagabo]

Everything I tried, except VLC, shows the Prores video with the higher black level of your Potplayer image.

I guess poisondeathray has it figured out.

[poisondeathray]

AE is not displaying it "wrong". It's displaying it as per BT.1866 because his working space is set to 709 2.4 display gamma. This applies an adjusted transfer curve function as per BT.1866 . It's a display gamma function, it's applied after the RGB conversion. (Underlying YUV values will be the same on a waveform , only the "appearance" of RGB converted values will change)

AE without color management (working space set to "none" ) looks like avisynth/potplayer etc...too , standard sRGB ~2.2 display gamma

I'm not sure if it's possible, but if you were able to enable color management on potplayer , look for BT.1866 or 2.4 gamma settings, it should look similar

[jagabo]

Yes, I posted before reading your post. Then updated my post.

[poisondeathray]

Not sure if potplayer can use cube luts directly, or if it can use ffmpeg libavfilters - but you can use a viewing cube lut applied through ffplay/ffmpeg's libavfilter 3dlut filter to apply the transform function

ffplay and mpv can do this . (But ffplay is a crappy "player" UI, and mpv for some reason drops frames when applying the lut)

potplayer has a vapoursynth and avisynth section ; not sure how to apply them in pp, but vpy, avs can apply cube luts, or vapoursynth can convert with the 1886 transform function with fmtc , so you might be able to use that indirectly in potplayer

The cube luts someone created on the creative cow forum, it looks pretty close to AE results
https://creativecow.net/forums/thread/luts-made-in-photoshop-look-different-in-premiere/
https://drive.google.com/open?id=1HHxxaOWifI3TEhBwEyGSl139x2jRM9dO

e.g path syntax on windows (pay attention to the escape character syntax, each "colon" requires a backslash, and all backslashes used forward slashes)

mpv

mpv --vf=lavfi=["lut3d=file='D\:/LUTS/srgb to bt1886 and bt1886 to srgb/bt1886 to srgb.cube'"] "Color Test.mov"

ffplay

ffplay -i "Color Test.mov" -vf "lut3d=file='D\:/LUTS/srgb to bt1886 and bt1886 to srgb/bt1886 to srgb.cube'"

[jagabo]

Potplayer does let you use AviSynth scripts internally. So you can probably come close to BT.1866 with Tweak(), ColorYUV(), RGBAdjust(), Levels(), and/or mt_lut().

[poisondeathray]

Potplayer does let you use AviSynth scripts internally. So you can probably come close to BT.1866 with Tweak(), ColorYUV(), RGBAdjust(), Levels(), and/or mt_lut().

Yes, I used to use kmplayer and then potplayer, but I've become less of a fan the last few years with all the spyware issues. I liked the GUI a lot.

I remember it had an avisynth and vapoursynth section where you could enter some text, but I never used it.


avisynth has an avscube function too, based on the vapoursynth cube function
http://www.avisynth.nl/index.php/AVSCube

LSmashVideoSource("Color Test.mov")
z_ConvertFormat(pixel_type="RGBP16", resample_filter="point", resample_filter_uv="bilinear", colorspace_op="709:709:709:l=>rgb:709:709:f")
Cube("D:\LUTS\srgb to bt1886 and bt1886 to srgb\bt1886 to srgb.cube")

[jagabo]

Just as a proof of concept, this delivers very close to the same levels and colors as the AE image in post #7:

potplayer_source()
ColorYUV(gain_y=16, off_y=-14)

[Attachment 57996 - Click to enlarge]

[poisondeathray]

Just as a proof of concept, this delivers very close to the same levels and colors as the AE image in post #7:

potplayer_source()
ColorYUV(gain_y=16, off_y=-14)

That's quite close in terms of brightness. It needs a bit more saturation, like tweak(sat=1.06, coring=false), or something like that

I would imagine coloryuv and tweak would run faster than a 64x64x64 cube LUT

Here is a shot with skin tones and colors (these were done in avisynth, I'm assuming potplayer would give same results with the avisynth box)

1886

[Attachment 58001 - Click to enlarge]

ColorYUV(gain_y=16, off_y=-14)

[Attachment 58002 - Click to enlarge]

ColorYUV(gain_y=16, off_y=-14).Tweak(sat=1.06,coring=false)

[Attachment 58003 - Click to enlarge]

[jagabo]

Yes, those tweaked colors look a little better. ColorYUV(cont_u=15, cont_v=15) will give about the same as Tweak(sat=1.06, coring=false). Putting it all in one ColorYUV() call might be a littler faster: ColorYUV(gain_y=16, off_y=-14, cont_u=15, cont_v=15).

[ObjectNull85]

Thanks for the replies! I checked PotPlayer's preference and it doesn't look like there is a BT.1866 setting I can choose anywhere so I might be stuck with gamma at 2.2 on that player. I'll play around with the settings you mentioned and see if I can get the image closer to a gamma of 2.4.

I guess the next thing to figure out is weather I should keep After Effects and Premiere's Color Space set to Rec.709 Gamma 2.4 or if I should set them to "none". Because this is going to broadcast first and web second I think I should keep the Rec.709 Gamma 2.4 Color Space even if it doesn't look right on my computer after I export. Unfortunately I don't have any way to test this on my TV other than using a MacMini or casting it from an iPad so I don't think I can accurately test how it would appear when broadcast.

To confuse things even more, I did a couple of tests and the export looks to have the correct gamma setting on Apple screens only:
• Windows / Samsung monitor / After Effects: Looks great, this is what I expect to see on export
• Windows / Samsung monitor / PotPlayer: Too bright
• Windows / Samsung monitor / Shift.io (website): Too bright (same as PotPlayer)
• MacBook Air 2020 / Shift.io (website): Looks great, just like After Effects
• iPad 2018 / Shift.io (website): Looks great, just like After Effects
• Mac Mini 2015 / Vizio P Series TV / Shift.io (website): Too bright (same as PotPlayer)

So as long as I used Apple screens (MacBook Air, iPad) my export looked as it should even if I viewed it on a website. I'm not sure what this means, maybe apps written for Apple products are color managed?

As I mentioned, I'm leaning towards just keeping the Color Space as Rec.709 Gamma 2.4 because that sounds like what I want for broadcast. Let me know if you'd do something different.

Thanks again!

[ObjectNull85]

So I found a setting in PotPlayer that makes the image look much closer to what I see in After Effects - it's not a perfect match but it's close.

In PotPlayer under Preference > Pixel Shaders > Pixel Shader Settings > Enable Display ICC Color Gamut Correction

ICC Color Gamut Correction is not checked by default but checking it darkens the image slightly getting it very close to what I want.

[Flavio S]

�� this was very clos indeed. If someone has made more progress than that it would be very much appreciated.

[coolgit]

Just one more thing to think of. If you are playing it on your TV then you need to go into TV settings and adjust HDMI gamma from 2.2 to 2.4.

[Theinvoker]

i think i have the same problem
what video card do you have? AMD?

i have the problem when i install the drivers. i never noticed it until last month so i tried to install old drivers but nothing changes. without drivers it's all good but obviously i need to install drivers