Colour shifts and questionable uploading quality

[azk4444]

Hi there,

So I know this has been talked about before but I could never really find a solution.

I just graded a music promo in resolve and exported the individual clips to ProRes 4444 & XML back to premier pro to add a few things, I.e titles etc.

If I click on the ‘view clip in finder’ and play the 4444 the colors don’t look as punchy although they look fine in the PP viewer. So I know that QuickTime has the issues with gamma and making images seem slightly washed out so I accepted what I saw on PP over the QT view.

I then exported the timeline 3 times to do some tests. A ProRes 4444, Pro Res 422hq and uncompressed 10bit.

1. 4444 – Looks washed out/desaturated in QT and just shows green overlay in VLC. Shows correctly if imported back into PP.
2. 422 – Looks washed out/desaturated in QT, but shows CORRECT colors in VLC. Shows correctly if imported back into PP.
3. Uncompressed – Shows correct colors in both players.

A sub question is there any fix to make them all show it accurately?

But my main concern is how they look when I upload them online.

I tried all the versions and none really show even close the accurate colors.

For example, I used apple compressor to compress the uncompressed 10bit version to H.264.mp4 at 720p & 1080p. They play fine on VLC and the colors look how I graded them. But when I upload it to Facebook and YouTube the colors change again becoming desaturated and slightly washed out.

Tried AME and Handbrake as well. Still the same issues.

Is this Facebook/YouTube encoder causing the issues? How can I counter it to get as accurate colors as possible on the media sites?

Thanks

[azk4444]

I have also seen on this forum that it might be something to do with colour space but I can't find out how to check and flag the colour space of a video when exporting it?

Does anyone know how to do that?

Thanks, a

[hello_hello]

Are you using a Mac? I typed the post below before realising you probably are. The levels issue is a common problem with PCs, but I'm not sure about Macs, but the info might still point you in the right direction.....

Sounds like a playback problem, more than an encoding one. Video normally uses limited range luminance levels (16-235), whereas PCs use full range (0-255). Play a limited range video using a PC without expanding it to full range and it can look washed out (for limited range 16 is black, for full range 0 is black, therefore 16 would be dark grey). VLC is probably doing the expanding, but QT isn't. Chances are it's not being expanded correctly when viewed in a browser either.

It'd possibly explain why the uncompressed video always displays correctly. Depending on what the "uncompressed" video is (ie RGB) it might be exported as full range rather than limited range.

In a perfect world if your "uncompressed" video is full range it'd be converted to limited range when it's re-encoded. That seems to be happening when you re-compress with the Apple compressor.

Have a look in your video card's control panel. For Nvidia it's under Video/Adjust Video Colour Settings. Whatever the card, try setting it so the video card expands video to full range. Hopefully that'll fix the QT problem, it'll also display as expected in a browser.

PS. If the above fixes the "washed out" look but the colours sometimes look a little "off" (ie red looking a bit darker or lighter than it should) that'd be a colour space issue, but someone else will need to help you there.

[azk4444]

Hi there,

Thanks for the reply.

Yes I am using a mac so I'm not sure we can check all the GFX settings form what I know, so I can't really follow those steps can I?

Its definitely more about the colours looking desaturated but it could be some sort of play back issue.

When its uploaded if I play it on safari its desaturated but on google chrome the colours look correct.

Does anyone know the cause of this and how to make it play correctly on all browsers?

Add; This seems to be the case with all youtube/facebook and vimeo videos depending if I watch them on safari or google chrome.

[hello_hello]

Sorry, I guess I'm not going to be able to help. It must be a levels issue but whether it's encoded wrong, or the level information is being set incorrectly in the video stream, or it's a playback problem etc.... Well if it's "all" youtube/facebook video displaying differently according to the browser used, that points to a playback problem. Maybe you could download a YouTube video and play it with QT to see if it's still the same. I couldn't even guess when it comes to Macs though. Hopefully someone else will come along.....

[jagabo]

As I understand it, youtube assumes rec.709 (8 bit, limited range: 16-235 for luma, 16-240 to chroma) for all uploads. If you upload rec.709 and your computer is set up correctly you will see exactly what you uploaded. Browsers often use the wrong matrix (limited range rec.601) delivering the wrong colors but the correct levels.

If your sources use full range YUV (0-255 for 8 bit, or 0 to 1023 for 10 bit) you'll probably need to convert to limited range. And if it's rec.601 (many DSLRs produce full range 601) you need to convert to rec.709.

If your computer is configured to display full range YUV (ie, black at Y=0, white at Y=255) you will see reduced contrast when playing "normal" video.

Also, quicktime is notorious for screwing up levels. I wouldn't trust anything it produces.

[azk4444]

Np hello I appreciate the help.

Hi Jaga, so how do I know if my computer is set up correctly? My monitor has been calibrated if thats what it is.

Sorry I am a bit ignorant to these types of issues. All I know is the video in my Premier/Resolve timeline displays the colours that I graded it too.

Once its uploaded to youtube Safari shows all videos (my uploads and every other youtube video) a bit desaturated and slightly darker, whereas Chrone shows the colours close to the graded colour although they are ever so slightly warmer and on the red side.

How can I check my sources colour range and then how can I convert it to do some tests?

Thanks

[jagabo]

Hi Jaga, so how do I know if my computer is set up correctly?

Get some rec.709 calibration videos. Adjust the video proc amp to display them correctly. I don't know how you do that on a Mac. If your software does't use the video proc amp while editing you'll have to look for settings that control the conversion of YUV to RGB. Look for rec.601/rec.709 and full/limited range settings. You may need to specify that for videos that the software interprets incorrectly. That's usually done by right clicking on the video in the assets windows or timeline and selecting Properties, or something like that.

My monitor has been calibrated if thats what it is.

That usually covers the display of RGB, not the conversion of YUV to RGB for display. Ie, the signal that runs over the cable between the graphics card and the monitor is RGB -- that is what you calibrated. YUV video has to first be converted to RGB before being sent to the monitor. That will be done by the graphics card (via its video proc amp) or the software.

[azk4444]

I will try to research this more using your advice but at the moment I don't quite understand how to follow all of your directions. Its a bit over my knowledge of all this type of stuff.

Getting rec.709 calibrated videos? A mac Processing amplifier?

Im using premier pro and I don't see any of that information from my timeline videos.

[jagabo]

This post has some links to calibration videos:

https://forum.videohelp.com/threads/374126-Poor-reds-in-Potplayer-with-MadVR?p=2410141&...=1#post2410141

The bars709flash.ts file should display with RGB components of 0 or 192. For example, the magenta bar should show R=192, G=0, B=192. In practice, plus or minus a few units due to rounding errors.

<edit>
Actually, you should start with this video: http://w6rz.net/ramp.zip

At the top left, to the left of vertical line of white dots, should all be the same shade of full black, R=G=B=0. At the bottom left, to the left of the vertical line of black dots, should all be the same shade of full white, R=G=B=255.