Jump to content

Color cast when uploading in 4K on youtube


Fredrik Lyhne
 Share

Recommended Posts

Some of you saw my skin tone comparison with the GX85 and GH4 that I uploaded last week and most people seem to prefer the ungraded image from the GX85 . That's fine with me as both grades were a little off. But I obviously had to take a closer look to see if I agreed. I suspected that youtube is doing something with the colors when I upload in 4K and it seems I was right. I uploaded a 1080p version and made a side by side comparison. For some reason youtube seems to add magenta when uploading in 4K. The result is that the ungraded footage of GX85 looks better and the graded image (which was a little too much in the first place) looks a lot worse. 

Has anyone else noticed this and is there a way to avoid it? 

4K is on the left and 1080p on the right. 

GX85u.pngGX85g.png

Link to comment
Share on other sites

Interesting discovery!

What I notice is the colour in the back ground. Checking the colours in a photo editor, I see the following values:

top left photo: topside back ground: R 176 - G 180 - B 176 lower side back ground: R 188 - G 198 - B 198

top right photo: topside back ground: R 177 - G 183 - B 177 lower side back ground: R 196 - G 204 - B 204

lower left photo: topside back ground: R 165 - G 166 - B 169 lower side back ground: R 186 - G 192 - B 203

lower right photo: topside back ground: R 175 - G 175 - B 177 lower side back ground: R 192 - G 198 - B 208

If I imagine a flat white back ground, I like the top skin colours a bit too green and warm, and the lower ones much too purple.

When I adjust the white balance for the top left face, I can get a very pleasing result.

Adjusting the WB on the others I can have good result too.

Maybe, to make things comparable, record using the same manual WB settings?

Maybe let the talent hold a colour checker, to measure the differences in the colour profiles, and see what has shifted where?

Link to comment
Share on other sites

23 hours ago, Fredrik Lyhne said:

Some of you saw my skin tone comparison with the GX85 and GH4 that I uploaded last week and most people seem to prefer the ungraded image from the GX85 . That's fine with me as both grades were a little off. But I obviously had to take a closer look to see if I agreed. I suspected that youtube is doing something with the colors when I upload in 4K and it seems I was right. I uploaded a 1080p version and made a side by side comparison. For some reason youtube seems to add magenta when uploading in 4K. The result is that the ungraded footage of GX85 looks better and the graded image (which was a little too much in the first place) looks a lot worse. 

Has anyone else noticed this and is there a way to avoid it? 

4K is on the left and 1080p on the right. 

If I was to hazard a guess, I'd think you've got a colour space conflict.  Youtube might be expecting that 4K uploads are in Rec.2020, but I don't know.  I couldn't find any recommendations about that.

Link to comment
Share on other sites

15 hours ago, Luke Mason said:

check your operating system for any ICC/ICM profiles and completely remove them all, reexport and reupload.

Thanks! Care to elaborate? Not sure what means and how to do that. I am on a mac btw. Im away for work for 2 weeks but I will look into it when I get back. 

4 hours ago, AKH said:

If I was to hazard a guess, I'd think you've got a colour space conflict.  Youtube might be expecting that 4K uploads are in Rec.2020, but I don't know.  I couldn't find any recommendations about that.

Thanks! So, is that something I can change in FCPX or on youtube? 

18 hours ago, Cas1 said:

Interesting discovery!

What I notice is the colour in the back ground. Checking the colours in a photo editor, I see the following values:

top left photo: topside back ground: R 176 - G 180 - B 176 lower side back ground: R 188 - G 198 - B 198

top right photo: topside back ground: R 177 - G 183 - B 177 lower side back ground: R 196 - G 204 - B 204

lower left photo: topside back ground: R 165 - G 166 - B 169 lower side back ground: R 186 - G 192 - B 203

lower right photo: topside back ground: R 175 - G 175 - B 177 lower side back ground: R 192 - G 198 - B 208

If I imagine a flat white back ground, I like the top skin colours a bit too green and warm, and the lower ones much too purple.

When I adjust the white balance for the top left face, I can get a very pleasing result.

Adjusting the WB on the others I can have good result too.

Maybe, to make things comparable, record using the same manual WB settings?

Maybe let the talent hold a colour checker, to measure the differences in the colour profiles, and see what has shifted where?

Thanks for confirming with the color picker, didnt think of that. I dont have a color checker, but I will definitely experiment with manual WB. But as Luke Mason and AKH says there seems to be some color space conflict.

Link to comment
Share on other sites

I've found that the browser color management plays a large effect. So far the only browsers that have given a "'correct" image like what I see viewing the file from my desktop are Microsoft Edge, Safari, and just recently Chrome.

Further, make sure you're not uploading something like H.265/264 to YT. The generational loss combined with the 4:2:0 space causes color shifts. I noticed far less color shift uploading a ProRes or DNx file versus H.264/265 which left my reds looking more magenta.

Link to comment
Share on other sites

18 minutes ago, iaremrsir said:

I've found that the browser color management plays a large effect. So far the only browsers that have given a "'correct" image like what I see viewing the file from my desktop are Microsoft Edge, Safari, and just recently Chrome.

Further, make sure you're not uploading something like H.265/264 to YT. The generational loss combined with the 4:2:0 space causes color shifts. I noticed far less color shift uploading a ProRes or DNx file versus H.264/265 which left my reds looking more magenta.

"generaion loss" and 4:2:0 subsampling do not cause colour shifts, ProRes has other issue (gamma shift), for Vimeo/Youtube upload, the safest way is using a medium-bitrate codec with .mxf wrapper, usually AVC-Intra 100 works the best.

Link to comment
Share on other sites

11 hours ago, AKH said:

That would have to be altered in FCPX, but I'm not familiar with it.  With a 4K timeline you should be able export a short clip in Rec.2020 to test on Youtube.

Thanks! I will look into it when I get back from work in a couple of weeks. Hopefully some of your suggestions work, otherwise I just have to upload in 1080p as that doesnt alter the colors. 

I have to say that I think this is really strange but could be that the standard settings for exporting 4K is different from 1080p in FCPX...

@iaremrsir Thanks for trying to help but this issue has nothing do with different browsers. All the images in the top post are from the same clip (4K on left, 1080p on the right) opened in Chrome. The problem is that the colors change when I export and upload on youtube in 4K while in 1080p it doesnt. 

Link to comment
Share on other sites

YouTube uses ffmpeg- this looks like an ffmpeg bug for videos > 1080p. Something related to bt601 / bt709 / rec2020 etc. I've also noticed this issue- too much saturation and red. The workaround has been to pull saturation and red, re-render, upload and check the results, repeating until it's OK. It might be possible to use ffmpeg locally to rewrap without transcoding and changing the color info (colormatrix etc.). See the options here: http://video.stackexchange.com/questions/16840/ffmpeg-explicitly-tag-h-264-as-bt-601-rather-than-leaving-unspecified. Flags to rewrap audio and video without transcoding: -c:a copy -c:v copy. 

Link to comment
Share on other sites

  • 2 weeks later...
2 hours ago, Orangenz said:

Can you post a 4k graded frame from your timeline to compare with the youtube result? I found the video interesting quite apart from the graded parts. 

Sure. Here is a ungraded grab from FCPX from the GX85:GX85_1.jpg

And here is one from youtube:

Skjermbilde 2016-07-05 kl. 17.21.01.png

What do you make of it? 

Link to comment
Share on other sites

  • 9 months later...
  • 10 months later...

I created an account just to share this. Sorry to bring up an old thread but I had the same problem and found the solution. Hopefully this can help someone else. 

For me the solution was to go to chrome://flags/ and press Ctrl+F (probably option+F on a mac) and search for Force Color Profile. I changed mine from default to sRGB and now FINALLY my 4k files look like 1080 files. I was getting the same muddy magenta cast to my 4k output files when viewed in chrome. Not anymore. 

Link to comment
Share on other sites

On 3/15/2018 at 12:08 AM, Jay Bates said:

I created an account just to share this. Sorry to bring up an old thread but I had the same problem and found the solution. Hopefully this can help someone else. 

For me the solution was to go to chrome://flags/ and press Ctrl+F (probably option+F on a mac) and search for Force Color Profile. I changed mine from default to sRGB and now FINALLY my 4k files look like 1080 files. I was getting the same muddy magenta cast to my 4k output files when viewed in chrome. Not anymore. 

People forget about color profiles all the time. You can't expect different apps to automatically display/read the same colorspace even in embedded ICM profiles, some apps simply don't respect this, rather use a profile that best covers a wider gamma by default. 

So what you did was force your app, in your case Chrome browser, to match the embedded ICM color profile of the video file, because Chrome was overriding it automatically, prefering a different colorspace instead.  

Also, don't forget that monitors and TVs all have their own preferred calibrated colorspace too. When you talk about color calibration and conformity, it's not difficult to get in the weeds quickly. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...