Channels & viewing

[kraM1t]

Was struggling with this for days, I finally fixed it.

Counter intuitively, selecting that I want to run the TV in Dolby Vision mode all the time worked, even though none of my content has it.

Now all HEVC has correct colour, hope it helps someone.

[Sladester]

Add me to the list of people this is happening to.  I have a 2021 Roku Ultra.  All was good until I upgraded the Roku to 11.5.  Now, in Plex, all HEVC is saturated red.  Nothing has changed plex-wise.  I also have the native Plex app installed on the same Samsung TV (the roku historically works better, faster, etc) and it is not happening there.  Just confirming this is definitely a roku issue.

I've tried most solutions in this thread (I think... there lots of pages) and none have helped.

[Sladester]

OK, following up... In my case, changing the display type on the roku seems to have fixed things.  Up until this problem, I had it set to Automatic forever.  The 11.5 update set it to Automatic (4K HDR10+).  I tried 4K Dolby Vision HDR TV (as suggested earlier), as well as 4K HDR TV and the problem persisted.  However changing it to "4K TV" seems to have corrected things, at least for me.  Thanks all, and good luck.

[DNL411]

@Sladester Changing to "4K TV" only works if you don't have any 4K HDR files.  You're basically telling Roku your TV isn't capable of HDR.

If you try to play a 4K HDR file with the "4K TV" setting, your Plex server will transcode HDR to SDR which uses a lot of CPU power unless you have hardware transcoding. You won't be able to Direct Play 4K HDR files.

[Sladester]

@DNL411   I definitely don't want that.  However in my testing, I'm not seeing any transcoding.  My test file, according to Plex, is 720p (HEVC Main 10).  When I play it I see it is direct play for both video and audio, again via the Plex dashboard.  This file was previously VERY red before while playing, now it looks normal. 

Is there somewhere else I should look to see that something else is happening?  I only know to check the plex dashboard.  

The TV itself is a Samsung Q80T QLED 4K UHD HDR Smart TV.  Is there a way to tell what it's settings in the Roku should be other than my trial and error?  I see it has 4K and HDR in the model, so I assumed the automatic setting of 4K HDR10+ was probably ok.

Thanks for your help.

[jbsjbs]

It's been awhile since I first experienced this problem and at this point I don't entirely recall which videos it occurred on. Does anyone have a sample file they can share -- obviously something that's permissable to post publicly -- that would help people to test various devices and settings and see what is affected?

If anyone would be willing to share or create such a video I'd be very appreciative. Thanks!

[DNL411]

@Sladester Only 4K HDR files will be transcoded if you set the Roku to "4K TV".  The 720p test file is not HDR so it will Direct Play.

The red is caused by HDR automatically turning on with non-HDR files.  By setting your Roku to "4K TV", you are disabling HDR completely so it can't turn on.

If you don't have any 4K HDR files, then you can keep the "4K TV" setting and you won't see the red coloring. By the way, 4K is also known as 2160p in case there is any confusion.

Please also keep in mind that if you keep the "4K TV" setting, all your other streaming apps like Netflix, Hulu, etc. also won't have HDR.  You'll just be watching regular SDR video.

[Sladester]

@DNL411 Well that is not good.  I need to find a better test file.  I have alot of HEVC which was having the problem that led me here, but I don't want to turn off HDR to fix.  Ugh.  Thanks for all your help.  It was very informative.

[Sladester]

@jbsjbs  I had the same thoughts.  Just found this.  I have not tested anything with it yet.

https://nascompares.com/guide/4k-1080p-hdr-hevc-and-uhd-files-to-download-and-test-your-plex-media-s...

[ftballpack]

The TV itself is a Samsung Q80T QLED 4K UHD HDR Smart TV.

Samsung TVs do not support Dolby Vision. I believe it's a licensing issue and instead, Samsung supports the Dolby Vision rival standard, HDR10+.

With the "always on Dolby Vision upscaling" glitch in the current Roku Ultra (as of the time of this post), even the newest high-end Samsung TVs will have problems with HEVC content if the "always on Dolby Vision upscaling" glitch is activated and outputting upscaled Dolby Vision to a non-Dolby Vision TV.

I previously described how the "always on Dolby Vision upscaling" glitch is triggered with MKV files that contain color flags in the MKV container and test files to show how the issue can be triggered.

I shared the info on this thread and with the Plex devs. Many tickets have been made with Roku to fix this issue since at least 2020. The speculation on the Plex thread I started about this issue is that the issue is hardware chip related, which is why Roku has not fixed the issue despite being made aware of the issues with HEVC content and the "always on Dolby Vision upscaling" glitch since 2020.

Link to my prior post on this thread explaining the issue:

https://community.roku.com/t5/Channels-viewing/Severe-color-contrast-distortion-while-Plex-streaming...

Link to my prior post on this thread with test files:

https://community.roku.com/t5/Channels-viewing/Severe-color-contrast-distortion-while-Plex-streaming...