When I tested this the last time it's been this:

If you use a YouTube video in regular sizes, it always expands studio swing to full swing.

If you use a YouTube video in full screen mode, video levels directly depend on the video settings of your grafic card, so it might be it did not expand the levels.

At the moment I'm not sure if there are further differences between YouTube's Flash mode vs. HTML 5 mode.

IE in Win 8.1, I get 0-255 full screen or not. Same in Firefox & Chrome.

I don't have Flash installed so I'm using HTML 5.

Youtube delivers both Flash and html5 correctly, given correct upload levels and flags. You state pretty clearly you have not done that, by uploading full range that is not flagged as such. You didn't actually state if you uploaded RGB or YUV. Critical difference.

Whether you've set your graphics card correctly is another matter entirely, and YouTube has no way to control that. As only one example, Dynamic Contrast affects exactly the kind of thing you describe, more often than not unpredictably. With so many layers of uncontrolled variables in the path, I can't draw any conclusions from your demonstration. This topic has been regurgitated so many times, I'm actually a bit sorry to see it being brought up again.

"I used a bunch of other people's test patterns for this . . ."
At the very least, you should be including full credit for each image used, and obtain permission up front before using any that are copyrighted. A properly constructed levels chart takes hours to get right.

just messing around. I don't know flags, so I just rendered and uploaded. it is/was 0-255 levels in the original... IE: you can see the 3 black PLUGEs in the color bars and other screens of black (If computer monitor are set right.

interesting to see others are getting varying results as well. I can't recreate my Chrome/Youtube fail now, but some updates have been installed since then: flash, shockwave, java, chrome....
maybe it is HTML5 making the difference?

posted again to see if youtube has changed anything since last year... things progress and they will to, eventually. they are doing 4k at 60p, 1080 60p... still waiting on 5.1 ;)

Vimeo supports 4K now

music vid, it is my PRIVATE test. do you want me to take it down? All images were easily downloaded via google search

Nothing's changed in Flash since Flash8.
Nothing's changed in HTML5 / Chrome since shortly after it was introduced.

You need to know about flags. By my quick estimate, there are 256 possible combinations, only 4 of which would deliver the proper levels on your monitor.
But happy messing around.

None of my images are in your video afaict, so there is no reason for me to ask you to do anything except include proper attribution, which is the minimum diligence expected.

It looks like 0-255 to me: Nice looking initially, but with the colors that would be the highs blown out and the darks all looking the same which would lose any detail in the shadows.

+1
Laurence

It's 0-255 (I downloaded it). No fullrange=on flag from Youtube, so ffmpeg or QT players don't stand a chance either.
All as expected = clipped.

so, my REAL file is fine: 0-255, I need to set special flag to TELL Youtube to leave it alone? Is that right?
Thanks for the extra knowledge. I don't know that I don't know many things, and you guys always help! :)

I would go the route of using 16-235 levels personally, rather than setting a flag telling Youtube or Vimeo what range to expect. It is industry standard for video and has been for a long time. The only reason we even have 0-255 for video is because of DSLRs and Canon and Nikon not knowing better and messing the ranges up.

I totally agree that 16-235 is the way to go, and is and always has been the broadcast standard.

But now, our computer screens, TVs, and mobile gizmos go beyond that. UHD, Dolby Vision, cinema movies are pushing for more. Maybe broadcast won't change, but other methods out there can do the extra levels and bits etc. Many movie trailers I've downloaded look really good and are full range in various players as well as inside Vegas.

UHDTV / Cinema levels are not 0-255. Not even close. Actually, UHDTV allows ~20% more of the CIE than Digital Cinema.

REC 2020 support in Vegas is still some time away, so that's when we can talk about this. 10 Bit UHDTV is still in relative infancy in the US.

0-255 on the web is a non-entity, and is unlikely to change very soon.
http://wolfcrow.com/blog/say-hello-to-rec-2020-the-color-space-of-the-future/

Smaller triangle is REC 709 (what we have now). larger triangle is REC 2020 (12 bit 4:4:4). That's a few trillion more colors on the palette. Everyone would need dedicated in-home fiber to enjoy it, or so it seems.