Channels & viewing

[2ka]

See this article for the MKV element specification:

https://www.matroska.org/technical/elements.html

You will see that the BT.709 color space is used in more than one element, including matrix coefficients, transfer characteristics, and primaries.

I believe the red bug only affects BT.709 material.  Generally speaking, older SD material will be BT.601.  HD and UHD will be BT.709.  And UHD HDR material will be BT.2020. There is also some UHD SDR material that is in BT.709.

[1DayAfterAnothe]

@2ka  so in other words if you see a "1" in any of the fields it's BT.709?  At least that's what I gathered skimming through that article

[2ka]

@1DayAfterAnothesaid:

"so in other words if you see a "1" in any of the fields it's BT.709?"

Well, not any of the fields (elements), but you get the idea.  Only three of the elements relate to colorspace.  But experience suggests it is important to delete all the color information elements to work around the bug.

You should understand that none of the color information elements are actually required for the codec to correctly play the video.  That's why it is OK to delete them.  MP4 containers don't even have the same kind of header structure that MKV containers have.

It appears, however, that Roku uses this information to configure the fancy video upscaler that is present in (only) newer models.  Apparently, there is a plain 'ol bug in the logic that configures the upscaler when the source material uses BT.709 colorspace and the color information is present in the MKV header.  It is that bug that makes everything look red and oversaturated.

[1DayAfterAnothe]

@2ka 

Gotcha...thanks for educating me on this...

Yes the files play perfectly fine with all of those elements removed.. I even checked several other HEVC MKV files I have and all of the fields are blank already....and I haven't touched them or removed the info...

I will say this.... It would be EASIER for me to just remux all files to MP4 instead of changing the colors....because I don't use surround... only stereo in all my files. In other words...It's either ac3 or aac 2.0.... Once in a while I might have a random HE AAC 2.0 or AC3 5.1.... but every single file I have I make sure that it direct plays before I put it on Plex....I don't want my server to have to transcode...and a series that is HEVC with AAC 2.0 would not transcode or even direct stream as long as I have the settings in Plex to direct play...

If I were a betting person... I'd say PLEX will give us a workaround before Roku fixes it....then again...It's been over a year so I don't know.

It's too bad I can't batch remove color elements... dealing with each file individually almost makes me want to just wait...

My Roku Ultra in my room is 2019....so I personally don't have an issue with any of my libraries on Plex playing back properly.... It's the person I live with who has a 2021 Roku Ultra who ran into my room and asked me to come look at something they were watching on Plex and it was red and I'm like WTF? They don't watch Plex that often so I guess they just happen to come across a certain effected file after all this time... That got me using their device looking for different shows to see if I could see the bug...and I found a few series/movies with the bug....but it's stuff they don't watch anyway....but my paranoid mind was thinking ... what if something happens to MY 2019 Roku in my room...I'll have to get an updated version which WILL have to bug... so do I fix this now... or hope that my Roku lasts and just wait for a possible fix ? LOL

sorry to ramble...thanks for all your help.. 

[Sladester]

Does anyone know if this happening in the latest version of the Ultra?  I have the 2021 model.  Looking at on Amazon and it says there is a newer 2022 version.  I wonder if the bug is still happening with that one.  

[1DayAfterAnothe]

@Sladester 

I think any Roku with Dolby Vision would suffer from this.

[DNL411]

@Sladester There is no Roku Ultra 2021, only a Roku Ultra LT 2021.

The latest Roku Ultra was released in 2020.  The Roku Ultra 2022 is exactly the same as the 2020 model but has an upgraded rechargeable remote.

[jtodd76]

I have been going through my MKV files and removing the elements under color information but came across several files that didn't have anything to remove under the color section but it was still red. Any suggestions?

[1DayAfterAnothe]

@jtodd76 

Is it direct playing? If it's direct playing... I'd say remux to MP4 and see what happens... It's a really quick process... I can't BELIEVE this is still going on after all this time...

Explain this one to me: So I have a series, right? Show red while direct streaming...the video is HEVC and the audio is AC3 2.0 (stereo)...If it direct streams it plays red...but if it direct plays it plays normally with no red... Now, take another series that is HEVC video but AAC 2.0 (stereo), right? It plays red regardless of it's direct playing or direct streaming. LOL..

So far... I have way too many files to remove color information from each file... so I'm waiting for a fix if there EVER is one!

[jtodd76]

Yes, I definitely have it on direct play and still getting the red tint. I'm starting to realize a majority of the files don't have any elements to remove....but still have the red tint with direct play. I'm just learning about this and reading on these posts...which software are you using to remux to MP4? Most of my files are MP4 except for those in 4K. This all started after getting new Roku's because our older Roku's (Which really weren't that old...maybe model 4660 or something) started doing annoying things with the remote controls. Like turning on the microphone when pause or play button is pushed or opening a random app when a show has been paused for a while and the screensaver has started. We'd have to hit the back button instead of hitting play. Most of these issues happened randomly.