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countrylac
Channel Surfer

Re: Severe color/contrast distortion while Plex-streaming HEVC+EAC3 videos.

Model 4800X

Software version 10.0.0 build 4165-C2

This happens anytime I play any SDR HVEC files locally through a USB drive or PLEX. I don't have this issue on any of my Roku Streaming Stick Plus or my previous 2018 Roku Ultra.

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countrylac
Channel Surfer

Re: Severe color/contrast distortion while Plex-streaming HEVC+EAC3 videos.

Danny, how do I provide the information to you directly? I don't want to post my serial number in a public forum.

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RokuDanny-R
Retired Moderator

Re: Severe color/contrast distortion while Plex-streaming HEVC+EAC3 videos.

@countrylac

Thanks for the post.

Feel free to send me a private message (PM). For more information about how to send a PM, visit our Community post here: Welcome to the Community


Thanks,
Danny

Danny R.
Roku Community Moderator
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ftballpack
Streaming Star

Re: Severe color/contrast distortion while Plex-streaming HEVC+EAC3 videos.

HEVC/SDR mkv files have not been working correctly on the 4800x for some time now. Any time someone tries to play an HEVC/SDR mkv on the 4800x, HDR will stay on continuously, distorting the picture.

I have seen the error also with mp4 files; however, those are usually mp4 files developed using various tools designed for creating mkv files then the video is extracted from an mkv and put into an mp4 container.

 

To create test/example videos that are easy to share I used a 25-second kitten video my wife took.

I used FFmpeg apt repo installed on Ubuntu 20.10 to convert the video from AVC shot on an iPhone 6S to HEVC. The 8-bit video put into both an HEVC 8-bit and 10-bit MKV container suffer from the “always-on HDR” issue.

i.e.
8-bit HEVC MKV:
https://mega.nz/file/wCxyyDaa#CIDGrGjshmQayWfPFsxI3smsMxsKUXXwx0VFatS-kho

10-bit HEVC MKV:
https://mega.nz/file/lXhUSL4A#piXjGM5OcOsEppuNEaw8gYsMEwJ1T_EQxjXwIwjn2HY

When I extracted the videos from the MKV using FFmpeg and put the videos into an MP4 container, the videos did not suffer from the “always-on” HDR issue, despite still being HEVC/SDR.

i.e.
8-bit HEVC MP4:
https://mega.nz/file/lOwiFDiR#1RT2us7vJglBYG4cs2c1Xd987jwXGdUfREfJCKekyfA

10-bit HEVC MP4:
https://mega.nz/file/lfxWzRaS#8SlZl9DMYNaLvEiYPRSafrjzi263yHzmsaRf4Q0mBeo

 

I currently have a ticket with Roku support about this issue and a Plex dev stated previously he was going to report this issue to Roku also.

Here are the two threads about this over at the Plex forums:

https://forums.plex.tv/t/roku-ultra-2020-aka-4800x-direct-play-colors-distorted-when-playing-back-he...

https://forums.plex.tv/t/hevc-movies-incorrectly-playback-in-hdr-on-2020-roku-ultra/657206/

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countrylac
Channel Surfer

Re: Severe color/contrast distortion while Plex-streaming HEVC+EAC3 videos.

Yeah, I've tired of this recurring issue and ended up buying an Nvidia Shield. I doubt I will be upgrading any of 7 Roku devices in the future.

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ftballpack
Streaming Star

Re: Severe color/contrast distortion while Plex-streaming HEVC+EAC3 videos.

I somewhat narrowed down the problem. To simplify it, HEVC/SDR content in an MKV container always plays back with HDR. Always.

Mp4 files on Plex that have aac audio suffer from the same issue as Plex transcodes all aac audio on the Plex server and directly plays the video, but the Plex Client on the Roku reads the transcoded audio/direct video playback from the mp4 as originating from an mkv container when only the audio is transcoded. Thus, causing the "always-on" HDR for HEVC/SDR in mkv container issue to apply to mp4s playback in Plex also.

In other words, Roku needs to fix the "always-on" HDR issue for HEVC/SDR content in an mkv container and everything else will fall into place and the 4800x will finally work correctly.

techjunkie
Channel Surfer

Re: Severe color/contrast distortion while Plex-streaming HEVC+EAC3 videos.

@RokuDanny-R

Started having the exact same issue about 2 software updates ago; specifically streaming from Plex (Direct Play, no on-the-fly transcoding)  After a lot of testing with videos that I know used to work, I think I identified the cause.

It seems when a video file is encoded in HEVC, but the color range standard is not specified in the video track, Roku will NOW default to HDR even if the video is SDR.

I tested this by transcoding a SDR video with without setting color range to BT.709 and then transcoding the exact same video with BT.709 setting.  The one with BT.709 played back with correct colors while the non BT.709 video had the saturation/contrast as reported by OP.

The working video track had these 3 additional fields while the non-working version are missing these:

Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709

Changing the audio encoding (EAC3, AAC, DTS, etc...) doesn't seem to make any difference

My guess is Roku changed some HDR detection defaults with the recent software releases where if it is not sure whether a video track is SDR or HDR, it will pass it as HDR.  Half of my video collection are no longer viewable as a result of this so I'd be happy to provide any additional info if it'll help with the fix.

Thanks

David

My Device: Model: 4800X - Roku Ultra

S/W Version: 10.0.0 build 4185-C2 (problem was present in at least 1 prior version)

 

ftballpack
Streaming Star

Re: Severe color/contrast distortion while Plex-streaming HEVC+EAC3 videos.

Changing the audio encoding (EAC3, AAC, DTS, etc...) doesn't seem to make any difference

The Plex Server will transcode AAC, DTS, and EAC3 5.1 audio down to AC3 5.1. DTS stereo is transcoded to AAC stereo by the Plex Server. The Roku will still directly play the video but the plex server will transcode the audio.

Thus, using EAC3, AAC, and DTS 5.1 will all result in the Plex Server transcoding the audio. Of the modern audio codecs, only AC3 5.1 audio is direct played on the Roku by Plex.

https://forums.plex.tv/t/roku-plex-acc-5-1-to-ac3-5-1-transcode-after-latest-update-to-v6-5-1/572161...

For whatever reason, if the Plex Client on the Roku shows the container is mkv when the audio is transcoded and the HEVC video is direct played, the Roku will play the video with HDR, no matter if the source is SDR or HDR. This is a result of the issues I described in my prior posts. The 4800x Roku forces HDR anytime the Roku believes the container is an mkv, which is what the Roku sees every time EAC3, AAC, or DTS audio is converted to AC3 and HEVC video is direct played from the Plex Server.

It does not matter if the original container is an mkv or not, if the source video is HEVC and the audio is transcoded, the plex client on the Roku shows the container is an mkv and the video will be played with HDR.

i.e.,

https://forums.plex.tv/t/roku-ultra-2020-aka-4800x-direct-play-colors-distorted-when-playing-back-he...

In my testing, converting the audio to AC3 and moving the audio and HEVC video into an mp4 container via ffmpeg allows for a complete direct stream of audio and video from the Plex Server, and the "always on" HDR issue stops. If the same audio/video combination is in an mkv, the "always on" HDR comes back right away.

Again, if Roku fixes the "always on" HDR issue with HEVC/mkv files on the 4800x, these related audio conversion/direct playback HEVC issues will be solved also.

Lastly, one of the test videos I uploaded earlier that works correctly has no color range listed yet, it plays back perfectly. Why? Because it's HEVC in an mp4 and it's completely direct played back, both video and audio. i.e., https://mega.nz/file/lfxWzRaS#8SlZl9DMYNaLvEiYPRSafrjzi263yHzmsaRf4Q0mBeo

I am 99% certain this issue has nothing to do with color ranges and everything to do with the way the Roku handles HEVC in an mkv container, which is also triggered by the Plex Server transcoding EAC3, AAC, and DTS audio with HEVC video not in an mkv container.

techjunkie
Channel Surfer

Re: Severe color/contrast distortion while Plex-streaming HEVC+EAC3 videos.


@ftballpack wrote:
Changing the audio encoding (EAC3, AAC, DTS, etc...) doesn't seem to make any difference

I am 99% certain this issue has nothing to do with color ranges and everything to do with the way the Roku handles HEVC in an mkv container, which is also triggered by the Plex Server transcoding EAC3, AAC, and DTS audio with HEVC video not in an mkv container.


Definitely related to HEVC in MKV container as all my videos are in that format and all my tests were with MKV containers so I can't speak to MP4 files.  I forgot to mention that in my post.  All I know is I can get Roku to handle SDR mkv videos correctly by simply adding those color range properties into the MKV metadata without re-encoding any of the AV tracks.  All my tests were with plex doing direct play for both audio and video.  Zero transcoding.

Perhaps there is more than 1 bug that was introduced into their recent software releases.  You mentioned you've been experiencing problems for awhile now, but mine only started within the last week or so.

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ftballpack
Streaming Star

Re: Severe color/contrast distortion while Plex-streaming HEVC+EAC3 videos.

You mentioned you've been experiencing problems for awhile now, but mine only started within the last week or so.

I think you are right. I just tried using FFmpeg to add your suggested color tags to an mkv video with no luck.

ffmpeg -i 'input.mkv' -map 0 -codec copy -bsf:v hevc_metadata=colour_primaries=1:transfer_characteristics=1:matrix_coefficients=1 -c:a copy -c:s:0 copy -c:s:1 copy 'output.mkv'

(I keep both an SRT and ASS version of the subtitle for my NTSC recordings, which is the reason for the map 0.)

The resulting file gives me these results:

Default : Yes

Forced : No

Color range : Limited

Color primaries : BT.709

Transfer characteristics : BT.709

Matrix coefficients : BT.709

Yet I am still seeing the distorted color. If you could please do me a favor, please open this short cat video with your 4800x Roku and see what happens. I can't make this video play properly unless I switch it from an mkv to mp4 container. I am beyond frustrated with the hours that I spent troubleshooting the issues with this thing. https://mega.nz/file/lXhUSL4A#piXjGM5OcOsEppuNEaw8gYsMEwJ1T_EQxjXwIwjn2HY

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