YouTube Screwing with Colors

[chris319]

Until recently the Chrome and Edge browsers rendered colors perfectly in YouTube videos.

I check the colors using an "eyedropper" color picker and an h.265 file containing patches of color of known values.

I checked the color rendition of my test file on YouTube using three different browsers (Chrome, Edge and Firefox). The colors are way off on all three browsers and on Windows Media Player.

I downloaded the test file to my local machine and got the same color errors I was seeing on line when viewing the file with VLC player. This tells me the file has been somehow modified while on the YouTube server.

I checked the original file which was uploaded from my machine to YouTube and got perfect color rendition with VLC player.

It appears something has changed at YouTube and it's screwing with the colors in video.

[jagabo]

You probably have a rec.709 vs rec.601 problem.

https://forum.videohelp.com/threads/329866-incorrect-collor-display-in-video-playback#post2045830

Youtube flags its encodings as rec.709. If you upload a rec.601 video it is encoded as if it's rec.709. Players that follow the flagged matrix will display the video incorrectly. VLC usually uses a rec.601 matrix to display video, even if the video is flagged as rec.709. The general rule is SD video should be rec.601, HD video rec.709. And both should be flagged while encoding. That gives you the best chance or proper playback. Unfortunately, some players will ignore the flags/rules and use one matrix or the other, assuring some of them will be played incorrectly.

You might also have levels problem, full range (YUV 0-255) vs. limited range (YUV 16-235). Almost all distribution formats use limited range and the player normally converts to full range RGB (what you see on the screen) during playback.

Upload a short sample before and after youtube.

[chris319]

You probably have a rec.709 vs rec.601 problem.

I don't. All that was straightened out a long time ago. It's 709 all the way.

You might also have levels problem

Nope, also long-ago dealt with.

As I said at the outset:

Until recently the Chrome and Edge browsers rendered colors perfectly in YouTube videos.

I have not re-encoded or re-uploaded anything. Those files have been sitting untouched by me on the YouTube server for months.

[chris319]

I just now uploaded my test file to Vimeo and got perfect colors, just like it used to be with YouTube.

By "perfect colors" I mean the R, G and B values are +/- 3. If the original value is, say, 150, then anything from 147 to 153 is considered acceptable due to rounding error.

[chris319]

This issue has been reported to YouTube.

Whether they will rectify the problem is anybody's guess.

[_Al_]

Does that different behavior includes previous uploaded samples all of sudden or it is a new thing, after you download new files, colors are off?

[poisondeathray]

Those files have been sitting untouched by me on the YouTube server for months.

How much "off" ?

I just checked some older videos and it looks ok in firefox here (the expected +/-3)

Jan 2019
June 2017

I have a few older ones but didn't check


Which version are you playing back? Check "stats for nerds" in the YT player

[poisondeathray]

But chrome is off, both YT and locally. Sometimes by 10-11

[chris319]

This is the current version. Disregard all others.

June 3, 2019

https://www.youtube.com/watch?v=AE1e9de0Tcs

[poisondeathray]

This is the current version. Disregard all others.

June 3, 2019

https://www.youtube.com/watch?v=AE1e9de0Tcs

Disregard which other ones? You only posted one in this thread...

The description says "uncompressed". What type of uncompressed did you upload to YT (what pixel format) ?

[poisondeathray]

I checked the color rendition of my test file on YouTube using three different browsers (Chrome, Edge and Firefox). The colors are way off on all three browsers and on Windows Media Player.

I downloaded the test file to my local machine and got the same color errors I was seeing on line when viewing the file with VLC player. This tells me the file has been somehow modified while on the YouTube server.

I checked the original file which was uploaded from my machine to YouTube and got perfect color rendition with VLC player.

My educated guess is you were working with studio RGB in vegas, exported uncompressed 8bit RGB, then YT converted to YUV using 601. That's why both colors and levels are not what you expect . Vegas has a bunch of quirks casual users probably don't know about, such as studio vs. computer RGB.

You said original file that you uploaded looks correct in VLC; well VLC does not render uncompressed RGB video correctly. VLC is buggy, and this is one of the many known issues. If it looks "correct", then it's actually probably incorrect

Do yourself a favour and check with
ffplay -i original.avi

I suspect it looks washed out, wrong levels, wrong colors to begin with .

[chris319]

Disregard which other ones?

These, which you posted:

Jan 2019
June 2017

My educated guess is you were working with studio RGB in vegas

You're making this more complicated than it need be and missing the obvious:

VLC does not render uncompressed RGB video correctly. VLC is buggy, and this is one of the many known issues.

You can't blame everything on bugs in VLC.

How do you explain this?

Until recently the Chrome and Edge browsers rendered colors perfectly in YouTube videos.

And this?

I just now uploaded my test file to Vimeo and got perfect colors, just like it used to be with YouTube.

To repeat, this file had perfect colors when first uploaded to YouTube. What changed in the intervening few months that the colors went bad? And why is Vimeo giving me good colors?

[poisondeathray]

Disregard which other ones?

These, which you posted:

Jan 2019
June 2017

Those referred to my videos. They are evidence that older uploaded videos work ok in firefox today. Wrong in chome today.

How do you explain this?

Until recently the Chrome and Edge browsers rendered colors perfectly in YouTube videos.

Chrome is off . Edge beta (based on Chromium is off too) . I don' t know if this is recent or not. I don't know if they were ever "perfect" in YT as you claim

Firefox is +/- 3. Today.

I just now uploaded my test file to Vimeo and got perfect colors, just like it used to be with YouTube.

Which test video ? same "uncompressed" video , or different ?

To repeat, this file had perfect colors when first uploaded to YouTube.

According to what? VLC?

Are you sure ? I doubt that one ever had correct colors, unless it was VLC, which means they were wrong.

Answer my question about the uncompressed video, or better yet, upload a sample here

What changed in the intervening few months that the colors went bad? And why is Vimeo giving me good colors?

Chrome gives wrong colors. Agreed

I don' t know what happened in the few months , maybe something on your end, drivers, setup etc..



Why are all my videos still good ? In firefox


Are you sure that you're not mixing up videos ?

Post samples of the actual videos that you uploaded to youtube and vimeo

[chris319]

Firefox is +/- 3. Today.

That's within tolerance.

According to what? VLC?

I already described my test methodology in this thread.

Are you sure that you're not mixing up videos ?

There is only one video with calibrated colors uploaded by me on YouTube.

maybe something on your end, drivers, setup etc..

The colors are good on Vimeo and on the local files, so we know my setup good. I think I would know if my video drivers changed.

You're grasping at straws.

Answer my question about the uncompressed video

I believe I have pretty well narrowed the problem down to YouTube (Vimeo is clean) so no point.

[poisondeathray]

The colors are good on Vimeo and on the local files, so we know my setup good.

Are you sure ? The VLC issue is known and factual . Just like the other VLC bugs I posted. When I mention bugs in VLC, they are specific ones that apply to specific circumstances. Do you have such a short memory?

I don't know if it was the same old file that you uploaded to YT as vimeo. I'm 99% certain it wasn't if you claim it's ok in vimeo

Upload the file you just uploaded to vimeo, but instead to youtube, and check in firefox

I believe I have pretty well narrowed the problem down to YouTube (Vimeo is clean) so no point.

Then why does YT work ok for me using firefox ? There is no problem that I can see . I just uploaded another video today and it was ok too (wrong colors in chrome) . Same with the dates of videos posted above

Why is your downloaded YT video messed up ? Did you know when you download from YT , you download the re-encoded version ? I posted the most plausible explanation - in fact I can recreate those circumstances on youtube with vegas, uncompressed RGB video and what "appears to be ok" on VLC, that's why I posted it.



If you want more help, answer the questions and upload the videos, otherwise figure it out on your own...

[poisondeathray]

I downloaded a portable chrome from January 2019 to check known test videos, same color problems locally and YT. Definitely one consistent problem is the browser (off by 11-12 or so in some channels). Checked both webm/ avc

[chris319]

Could you post a link to your test video?

[poisondeathray]

Could you post a link to your test video?

Clarify what exactly ? Do you mean youtube link that I uploaded earlier today ? or local file that I uploaded to youtube ? Or older YT link to see if something "changed" - if so which date? Or something else entirely?


I'd be surprised if the video you uploaded to vimeo today (I'm assuming it's not uncompressed), did not look ok if you uploaded to YT right now (in firefox, that is)

[chris319]

Do you mean youtube link that I uploaded earlier today ? or local file that I uploaded to youtube ? Or older YT link to see if something "changed" - if so which date? Or something else entirely?

The one with the best color accuracy.

[poisondeathray]

Do you mean youtube link that I uploaded earlier today ? or local file that I uploaded to youtube ? Or older YT link to see if something "changed" - if so which date? Or something else entirely?

The one with the best color accuracy.

They are all the expected +/-3 in Firefox .


These aren't exactly the same videos (different resolution, one has running frame number) , but main bars should be the same +/-3 in Firefox . Or if you download the video and play it back properly

I notice that the preview poster frame is the wrong color (probably wrong matrix when they used their screenshot taking), but the video changes to the correct color when you play the video

Jan 06,2019
https://www.youtube.com/watch?v=Hx2wBdrb-cw

Sept 27,2019
https://www.youtube.com/watch?v=hIT_Xh9dAoY

AFAIK, nothing "happened" suddenly to youtube . Unlikely that something affects only June 03 , 2019 videos. I don't have any uploaded that day on any accounts

[chris319]

PROBLEM FOUND!

There was a color error in "uncompressed" which has been removed from YouTube. Everything OK now.

Firefox has finally fixed its color error and now renders in 709 rather than 601 as previously.

What are the colors supposed to be in the Belle Nuit chart?

[poisondeathray]

What are the colors supposed to be in the Belle Nuit chart?

you can download the original chart(s) here
https://www.belle-nuit.com/test-chart

Main bars are 180 and 16 . e.g. "red" would be 180,16,16 . "green" would be 16,180,180

Firefox has finally fixed its color error and now renders in 709 rather than 601 as previously.

Did you double check in Chrome / Edge ? Did you get more "off" than expected too as well ?



The Mozilla team is actually make progress with 10bit too over the last year

If you recall, 10bit YUV should be +/-0 for 99.99% of the 8bpc RGB colors (It is in proper player software, like MPCHC . Not VLC, which does the "fast" conversion )

Right now FF uses libyuv and emphasizes speed (like VLC) for the RGB conversion and goes through 8bit YUV before RGB . But there has been work over the last year to do this properly

Why does this matter ? HTML5 supports 10bit444/422/420 right now, with VP9/WebM . Both chrome/firefox can play it right now . The problem is the inaccurate conversion to RGB. Once that gets fixed, that means perfect video (in terms of color accuracy), and no subsampling when using 444 . YT might not host it, but on your own sites where accuracy is required

[chris319]

Did you double check in Chrome / Edge ? Did you get more "off" than expected too as well ?

Yes. In Chrome, the blue channel in the green patch is 21 (supposed to be 16). I would like to see it closer but oh well.

Edge and Firefox are +/- 3.

Right now FF uses libyuv and emphasizes speed (like VLC) for the RGB conversion and goes through 8bit YUV before RGB . But there has been work over the last year to do this properly

How do you come by this information?

Main bars are 180 and 16 . e.g. "red" would be 180,16,16 . "green" would be 16,180,180

These are the exact same RGB values for SMPTE RP 219 and ARIB bars. They're what I use in my test pattern.

[poisondeathray]

Yes. In Chrome, the blue channel in the green patch is 21 (supposed to be 16). I would like to see it closer but oh well.

I'm getting 27 in YT, and 27 on a local file for chrome for 8bit, 28 for 10bit

How do you come by this information?

https://bugzilla.mozilla.org/show_bug.cgi?id=1540919

[chris319]

I'm getting 27 in YT, and 27 on a local file for chrome for 8bit, 28 for 10bit

Which file are you looking at?

What do you get with this:

https://www.youtube.com/watch?v=PdIK-mqMlzw

[poisondeathray]

I'm getting 27 in YT, and 27 on a local file for chrome for 8bit, 28 for 10bit

Which file are you looking at?

YT video that I uploaded today . And 8bit/10bit VP9 videos, but also the video uploaded to YT

What do you get with this:

https://www.youtube.com/watch?v=PdIK-mqMlzw

In FF, "green" 14,180,14 ; "red" 179,15,14
In Chrome, "green" 6,179,27; "red" 180,16,16

[chris319]

Chrome, "green" 6,179,27

That's pretty far off for red and blue.

[poisondeathray]

Yes, I'm looking into it and various chrome flags.

HW off is completely wrong (601)

But "force color profile" sRGB fixes it . Now it's +/-3 too . AFAIK default chrome setting is not shipped like that

On your video
green 15,179,16
red 180,15,15

[chris319]

Thanks for that. Now I'll have to set all of my Chrome installations that way.

If the Firefox color errors have indeed been fixed, I don't suppose Firefox has anything like that, does it?

I was totally surprised to find that Firefox had been fixed, having filed several entries in that bug report. It had been rendering using 601 coefficients.

BT.601 was never intended for computer video, having been developed when the IBM PC was capable of a whopping 16 colors. BT.601 was supposed to be a bridge between analog and digital video.

https://bugzilla.mozilla.org/show_bug.cgi?id=1300170

[chris319]

I tried configuring Chrome as described above. The blue channel still comes in at 21 when it should be 16 (13 - 19).