Channels & viewing

[Sladester]

@ftballpack That all makes sense but this issue, in my case, just began.  I've had the TV and the Roku for over a year or more.  I think it could be part of the Roku update to 11.5 OS.  Alternatively, it could have been part of a PMS update as well.  In either case, whatever was changed recently is causing the issue.  It would be nice to be able to revert it back.

[ftballpack]

In either case, whatever was changed recently is causing the issue. It would be nice to be able to revert it back.

You missed the point of my post. The issue described in this thread has been present since at least 2020.

In my last post, I shared with you links to two copyright-free kitten videos to test if the issue described in this thread is affecting your setup. If neither of those videos triggers the "always on Dolby vision upscaler" issue described in this thread, you have a different problem from what is described in this thread and should start a new threat about your issue.

If your issue is a result of the RokuOS 11.5 update, than start a thread about that or in the alternative start a thread on Plex about this issue is you believe Plex may be the cause of your issues.

Adding your "new" issue to a thread for a known issue that has existed since at least 2020, all you are doing is creating confusion and it does not help the Roku devs to have two separate issues conflated together into one thread.

[ftballpack]

The red is caused by HDR automatically turning on with non-HDR files.

tl;dr The issue has nothing to do with HDR. It's the Roku's Dolby Vision upscaler being triggered when it's not supposed to be triggered.

The red is not caused by HDR being triggered. The red issue is caused by the Roku Ultra 4800x's built-in Dolby Vision upscaler being triggered when it is not supposed to be. The "dolby vision upscaler" can be triggered even if the maximum TV output is set for 1080p, which the 1080p standard (8-bit) most definitely does not support all of the colors that the (12-bit) Dolby Vision standard does.

For a super "quick and dirty" explanation, SDR aka the 1080p standard is 8-bit, HDR aka HDR10 the OG 4K standard is 10-bit video. All 4K sets can process HDR video as it's an open standard. The "new" competing standards are HDR10+ which is a 12-bit open standard supported by Samsung among others. The other competing standard is Dolby Vision a 12-bit standard that is patented by Dolby and thus subject to royalty payments, which is supported by Sony among others.

Dolby Vision has a wider color and brightness range than HDR10+ which is why it's as popular as it is despite the royalty payment costs. Many of the newer Rokus sold by Roku have a built-in Dolby Vision upscaler that can be triggered to activate despite the television not supporting Dolby Vision, thus the color glitch issues, which occur on 1080p sets.

Setting the Roku to 4K or 1080p still can trigger the "always on dolby vision upscaler" glitches despite the Roku being set for a lower color depth. That's the known issue that this entire thread is about.

More info about the competing standards for those curious: https://www.rtings.com/tv/learn/hdr10-vs-dolby-vision

[2ka]

ftballpack has the right idea in asserting that the bug is related to incorrect operation of the upscaler in some newer model Rokus.  I agree that the bug is triggered exactly as ftballpack says, when such a newer model tries to play content from an MKV container with color info in the header.  I would add that I think it happens (only) when the video is HEVC encoded in the BT.709 colorspace.

The thing that makes this bug more confusing is that the triggering container format (MKV with color info in the header) is exactly the one the Plex server uses when recontainerizing content for Direct Streaming.  That means that even if the source was in a different container type or has had the color info stripped from the header, the bug can come back if the Plex server tries to Direct Stream the content in a new container.  This can happen for seemingly unrelated reasons.  The most common one is if the server thinks the audio isn't compatible with your playback environment.  In that case the server will transcode the audio to a compatible format, and put it together with the video in an MKV container complete with color info in the header.  The server will also recontainerize the content if the AAC stutter workaround is turned on in the player's advanced settings.  And so, the bug will come back to life.

On the flip side, the bug will go away for reasons that are less than obvious.  If Plex decides to transcode your video for any reason, it uses the H.248 encoder instead of HEVC.  So if Plex thinks the video needs to be bitrate limited, or if Direct Play and Direct Stream are turned off in the player, or if Plex thinks the video isn't compatible with your TV, the bug will go away.  Alas, so will 4K resolution and/or HDR.  Plex will transcode at FHD or HD resolutions (not UHD), and in SDR (not HDR).

I really think that those that are experiencing this bug for the first time in Roku 11.5 are seeing it because of some setting that changed, causing previously Direct Played content to be Direct Streamed.  And those that are seeing the problem go away by changing their display type settings are likely triggering H.248 transcoding, with concurrent loss of resolution or dynamic range.

The best way to understand this is to watch the Server's console (if you have access) during an offending playback.  Look for signs that the video is being recontainerized and Direct Streamed.

[2ka]

@Sladester, check to see if the AAC stutter workaround got re-enabled during the upgrade.  Look in the Player's Advanced settings.  When this is turned on, the Server will recontainerize the content in an MKV container with colorspace info in the header, triggering the bug.  Check also to make sure Direct Play is enabled.

If that doesn't shed any light watch the Plex console during an offending playback, and see if the file is being Direct Streamed (Recontainerized).  That will trigger the bug if it is.  Look for reasons why it might be being Direct Streamed, such as AAC surround sound audio in the original file.

[DNL411]

@ftballpack I was specifically addressing Sladester's post. He stated setting his Roku to "4K TV" fixed his red coloring issues.  So I was simply informing him that his fix was simply disabling HDR on his Roku.

I apologize if I'm providing info not related to this thread.

[no1jam]

It’s a pretty aggravating problem. I use handbrake Roku preset to encode the media I buy and it generally plays on anything. This 2021 Roku ultra is the only player I have that does it. Does it on an old Samsung lcd tv, a slightly less old Vizio tv, on a 5-6 year old Samsung tv,

but not on my tcl 4k Roku tv.

i “fix” it by turning on subtitles to force the transcode. PGS, VOBSUB, or UTF-8 (aka ASS) all fix it like this.

old tv shows do it, dvds, blu rays all do it, fairly certain 4k’s do it also

/annoying

[2ka]

@no1jam, that "fix" certainly works, but it is pretty heavy-handed.  You get (potentially) unwanted subtitles, and you lose 4K resolution.

Try this fix:

During Handbrake-

• Make sure you add an AC-3 audio track, even if you have to transcode it from some other audio format.  This stops Plex from wanting to transcode new compatible audio and then recontainerizing the whole thing.
• If you use an MKV container, use the header editor in MKV Toolnix (free program) to delete the color info in the video track.  Should be pretty self-explanatory how to do this, but I can provide more help if it isn't.

During Playback (on the Roku)-

• Make sure the AAC stutter workaround is disabled.  Look in Advanced Settings.
• Make sure Direct Play is enabled.

This should stop the problem without any loss of anything.

[no1jam]

@2ka 

Thanks for the info, seriously.

I’ll certainly consider the solutions provided.

Removing the color info certainly seems like the best solution in my case. I simply have so much of my library, almost all of it, encoded as 265 from my purchased movie collection.

My only 4K tv doesn’t have the problem with the 2021 player.

TBF, I’m more likely to just replace the 2021 Ultra with a different device if my setups get rearranged.

and 100% not going to be blindly buying Rokus anymore 😕 

unfortunate, as they’ve been my go to and rock solid for a long time for me

[jbsjbs]

I'm so appreciative of all the detailed information and analysis that's gone into this. I haven't commented on this thread in awhile because at some point I checked the AAC Stutter box and then hadn't seen the problem again. But today I downloaded the kitten videos that @ftballpack recommended and tried them out on my 4k Sony HDR TV. With the AAC stutter box unchecked, I got the bug. Checked, no bug (pics below).

I've since gotten my hands on a 2019 Ultra and while I haven't tested it yet I assume it will not have this issue. So the question I have is, is there much downside to keeping the AAC Stutter box checked if that solves the red issue? Would you stick with that or switch to the 2019?

https://i.imgur.com/ouK7TG8.jpg