4K HDR on Plex

[Atra1n2]

I wasn't sure if this was the proper place for this, so any mods, please move it if not... So I have some 4k HDR Blu-Ray rips on my Plex server. They are MKV files output from MakeMKV. When I stream them to my Element Roku 4K HDR tv, they play in 4K HDR as indicated by the little popup when HDR 10 info is detected by the TV. However, it seems the Plex server is having to transcode the 4k MKV file to stream to the TV and its causing occasional stutters and buffering. Does anyone know the proper settings for something like Handbrake to transcode the file to something that can direct play on my roku tv and not need any encoding while preserving the resolution and the HDR color? These are approx. 55 GB files for approx. 1hour 30 min. movies. The files typically have a 7.1, 5.1, and a few stereo audio streams for multi language support, as well as several subtitle files. Also the rips are in HEVC. I'm fine with any format or container so long as I can direct play it in 4k HDR through the plex app on my element roku tv.

[FloRolf]

Maybe you should take a look at your cpu usage on the Plex Server to see if it holds up. And maybe the ethernet traffic, but that shouldn't be a problem. 

[lieder1987]

4 minutes ago, FloRolf said:

Maybe you should take a look at your cpu usage on the Plex Server to see if it holds up.

Plex has a pretty good article on their site that outlines the requirement for different resolution types for streaming (if they support it), but also make sure you are trying to do a direct stream instead of the transcode. That might also help.

[Atra1n2]

@FloRolf @lieder1987 I've set the Plex app to force direct play and direct stream, but the plex server still has to transcode. Something about the files it doesn't like and has to transcode I guess and when your dealing with large 4k files like that, even modern hardware can struggle with it. My sever is running a r7 1700 and 32gb ram.

[lieder1987]

So here is a pull directly from their site:

CPU Requirements

The most basic thing to remember is that the more Plex apps you have playing content at the same time, the more CPU power you’ll need. Generally speaking, if you have two Plex apps requiring transcoded content at the same time, that will require about twice the CPU processing power compared to if there was only one app playing content.

If you want very basic minimum suggestions:

• No transcoding: Intel “Atom” 1.2GHz (NAS devices based on ARM processors should also be capable of at least one stream with no transcoding)
• Single 720p transcode: Intel Core i3 3.0 GHz
• Single 1080p transcode: Intel Core i5 3.0GHz
• Single 4K transcode: Intel Core i7 3.2GHz

 

The Guideline

Very roughly speaking, for a single full-transcode of a video, the following PassMark score requirements are a good guideline for the following average source file:

• 4K (60Mbps, HEVC) file: 4000 PassMark score (being transcoded to 10Mbps 1080p)
• 1080p (10Mbps, H.264) file: 2000 PassMark score
• 720p (4Mbps, H.264) file: 1500 PassMark score

https://support.plex.tv/articles/201774043-what-kind-of-cpu-do-i-need-for-my-server/

 

Based on your CPU this should be no issue, but the HDR or the way you have the container might be causing an issue.

[Atra1n2]

3 minutes ago, lieder1987 said:

So here is a pull directly from their site:

CPU Requirements

The most basic thing to remember is that the more Plex apps you have playing content at the same time, the more CPU power you’ll need. Generally speaking, if you have two Plex apps requiring transcoded content at the same time, that will require about twice the CPU processing power compared to if there was only one app playing content.

If you want very basic minimum suggestions:

• No transcoding: Intel “Atom” 1.2GHz (NAS devices based on ARM processors should also be capable of at least one stream with no transcoding)
• Single 720p transcode: Intel Core i3 3.0 GHz
• Single 1080p transcode: Intel Core i5 3.0GHz
• Single 4K transcode: Intel Core i7 3.2GHz

 

The Guideline

Very roughly speaking, for a single full-transcode of a video, the following PassMark score requirements are a good guideline for the following average source file:

• 4K (60Mbps, HEVC) file: 4000 PassMark score (being transcoded to 10Mbps 1080p)
• 1080p (10Mbps, H.264) file: 2000 PassMark score
• 720p (4Mbps, H.264) file: 1500 PassMark score

https://support.plex.tv/articles/201774043-what-kind-of-cpu-do-i-need-for-my-server/

 

Based on your CPU this should be no issue, but the HDR or the way you have the container might be causing an issue.

This tmentions being transcended to 10mbps 1080p, but I'm trying to stream it in original 4k (approx 55-60 mbps) over gigabit ethernet and the TV is wired so bandwidth shouldn't be the bottleneck.

[lieder1987]

This article says that only certain Rokus are certified to run 4k...so it could have to transcode because your player isnt supported for plex 4k.

 

https://support.plex.tv/articles/214577427-is-4k-content-supported-on-the-roku/

[Atra1n2]

28 minutes ago, lieder1987 said:

This article says that only certain Rokus are certified to run 4k...so it could have to transcode because your player isnt supported for plex 4k.

 

https://support.plex.tv/articles/214577427-is-4k-content-supported-on-the-roku/

Mine should support it as it's a roku that is integrated into a 4k HDR Element TV. The TV itself runs the Roku OS.

[Atra1n2]

33 minutes ago, lieder1987 said:

This article says that only certain Rokus are certified to run 4k...so it could have to transcode because your player isnt supported for plex 4k.

 

https://support.plex.tv/articles/214577427-is-4k-content-supported-on-the-roku/

I'm beginning to wonder if it's an audio codec issue that causes it to transcode. The Blu-ray rips contain 7.1 and 5.1 audio streams that may not be supported on the plex app of my tv and it may cause it to have to transcode the entire file again.

[lieder1987]

Im betting its the player, but good luck.

[tikker]

22 hours ago, Atra1n2 said:

may not be supported on the plex app of my tv

I have no experience with Rokus, but does this work correctly? I.e. could it be that by using the TV Plex app your server sees your TV as the client and not the Roku?

[Atra1n2]

17 hours ago, tikker said:

I have no experience with Rokus, but does this work correctly? I.e. could it be that by using the TV Plex app your server sees your TV as the client and not the Roku?

It's a Roku TV, as in the TV itself runs the Roku OS, no additional hardware. See here: https://www.elementelectronics.com/tvs/roku/ I believe it may be something to do with the container. It will direct stream the files, it just will not direct play them (2 different things in "plex speak"), which would be ideal as the server would not be doing any processing, merely sending the untouched file over the LAN. However the direct streaming isn't terribly CPU intensive, the player just seems to buffer a bit in the beginning before it begins playing smoothly.

[tikker]

4 hours ago, Atra1n2 said:

It's a Roku TV, as in the TV itself runs the Roku OS, no additional hardware. See here: https://www.elementelectronics.com/tvs/roku/ I believe it may be something to do with the container. It will direct stream the files, it just will not direct play them (2 different things in "plex speak"), which would be ideal as the server would not be doing any processing, merely sending the untouched file over the LAN. However the direct streaming isn't terribly CPU intensive, the player just seems to buffer a bit in the beginning before it begins playing smoothly.

Are you using subtitles? Those always give me issues either triggering a full transcode or direct streaming instead of direct playing. In the latter case it's always due to the audio used. IIRC Plex doesn't handle DTS-HD or TrueHD very well (if at all), yet again I only seem to run into these things when using subtitles. I have yet to find a single thing I can't direct play over my network if I turn them off.

[Atra1n2]

5 hours ago, tikker said:

Are you using subtitles? Those always give me issues either triggering a full transcode or direct streaming instead of direct playing. In the latter case it's always due to the audio used. IIRC Plex doesn't handle DTS-HD or TrueHD very well (if at all), yet again I only seem to run into these things when using subtitles. I have yet to find a single thing I can't direct play over my network if I turn them off.

I'm not using subtitles but I wonder if I need to leave them out of the ripped files altogether and maybe exclude some of the fancier audio streams.