Channels & viewing

[Awponder]

I am on roku os 11......and your suggestion did not work. Thanks though!

[2ka]

Hi Guys,

If you will carefully read this entire thread (maybe a pretty tall order), especially my posts and those from ftballpack, you will see that the triggers and causes of this bug are pretty well understood.  You will also see that neither turning of the sound sound stutter fix nor using an MP4 container are reliable workarounds.  I'll try to explain why this is.

The bug is triggered whenever UHD HEVC content is played on a late model Roku from an MKV container that also contains colorspace/chroma information.  Unfortunately, this is the go-to format that Plex uses to recontainerize the content after a partial transcode (regardless of whether or not the original content was in an MP4 container).  These partial transcodes most often happen to cure sound incompatibilities with the playing equipment.  They also occur with the sound stutter fix.

Here are the only reliable way to work around the issue:

1. Make sure your original content is in an MP4 container or in an MKV container that has the colorspace/chroma information completely deleted from the header
2. Make sure your original content contains sound that is completely compatible with the Roku and your playback equipment.  For surround sound, I suggest AC3 as being the most commonly supported.  For plain stereo sound, AAC generally works well too.
3. Make sure Direct Play is enabled, so the Server isn't forced to recontainerize the content.

[Awponder]

Yea changing to audio that my roku won't transcode and removing things from header works on the roku, but dang what a pain the in **bleep** to have to do that for every single file I have.

[no1jam]

Just wanna offer this: it’s non UHD content for me as well. It’s DVD’s and Blu Ray’s as well.

[Awponder]

I have no issues with non 4k content. Even in HEVC 10bit. Can't see a reason why you would have that issue.

[no1jam]

Because it’s not about UHD content specifically. It’s about HEVC .mkv header information and certain model Roku’s.

I have two 2021 Roku Ultras with this problem. My 2019 ultra doesn’t have the problem

[Awponder]

The files I have edited, to remove color space info etc are now not working anymore and are way too red and too much saturation again.

[2ka]

Awponder,

This is almost certainly because the Plex server is placing the content in a new container -- i.e. Direct Streaming.  When Plex does this it uses an mkv container and reconstructs the color space info in the header, causing the bug to come back to life like a zombie.

If you have access to the dashboard of your Plex server, check it during a problem playback to see if the file is being transcoded and/or direct streamed.

There are several reasons this can happen, but there are workarounds:

1. Direct Play might be disabled, forcing Direct Streaming. Double check your player's profile settings and the playback settings of the content to make sure Direct Play is enabled.

2.  The file may contain audio which is incompatible with your playback equipment, causing the server to transcode the audio and place the content in a new container.  Check the audio settings on your Roku to make sure they are correct.  Since AC3 is the Lingua Franca of surround sound, I recommend using that codec for 5.1 audio.  AAC can be used for stereo.  AAC 5.1 is a problem, and will cause transcoding.

3.  Direct streaming happens if you are using an external subtitle file.  Try turning subtitles off in the Plex player to see if this is the problem.  If you are using an external subtitle file and you really need subtitles, you can use a tool like mkvtoolnix to graft the subtitles right in to the original container so that it can be Direct Played.

There are other reasons Plex might choose to transcode, like bandwidth limitation or burned-in subtitles, for example.  But when Plex transcodes the video, it always uses the H.264 codec instead of HEVC (at least in the current version), so the problem goes away.  So does your 4K resolution though.  On Plex, H.264 transcodes are limited to 1080P.

[Awponder]

So did something change to make this happen? The workaround provided works....then it didn't now it works again. I am so confused. 

[2ka]

Awponder,

It's possible that some setting has changed in your player or playing environment.  I'd recommend careful diagnosis, looking at each of the things I mentioned in my previous post.