Anyone out there know why the latest PMS, on a powerful Nvidia Shield, over Ethernet, transcodes 8-bit HEVC to H.264 for TiVo Bolt and Apple TV 4K, both of which have HEVC support per Plex?
What is the video container? I believe it will still transcode mkv’s, I have read somewhere it will direct play mp4’s though. And can confirm this using both my nvidia shield and my lg tv webos3 plex clients.
All of my videos are MKV files due to the greater flexibility of the container.
6/22/17 Plex for TiVo Release Notes
“TiVo: Now Direct Play and Direct Stream more UHD content on your UHD capable TiVo devices. The Plex for TiVo app will now Direct Play UHD content in MP4 and MKV files.”
My videos are primarily 1080p, but there’s no way I’ll believe that it can handle 4K, but not 1080p… lol
11/8/17 Plex for Apple TV Release Notes
“NEW:
Add direct play support for HEVC video codec.”
This note leaves more open to interpretation than the TiVo notes… it could be that only MP4 works on the Apple TV. (Though I have a tvOS app called Infuse that plays MKVs just fine - it just doesn’t have all of the Plex Features.)
Also - I saw some vague discussion about editing the tvos.xml file to make it work - I just don’t understand why that is the necessary solution when the Apple TV 4K is more than capable of playing MKV files over the local network smoothly without transcoding. This is demonstrated by other video player apps such as Infuse and VLC.
Apple historically has not supported MKV containers. All content to them must be remuxed into a MP4 stream.
Remux is not transcoding (changing the video encoding). It is only changing the container from MKV -> MP4.
VLC and Infuse natively accept MKV containers and therefore do not qualify as valid defining criteria. ( I use both apps. I also only use MKV files )
Try to import MKV into your iDevice and play with the native player (not an app).
Repeat the sequence with a MP4 and observe proper playback.
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@ChuckPA said:
Apple historically has not supported MKV containers. All content to them must be remuxed into a MP4 stream.
Remux is not transcoding (changing the video encoding). It is only changing the container from MKV → MP4.
First of all, thank you for your response - I don’t know if I’ve ever had a member of the Plex team reach out to answer a question for me, which can of course be quite frustrating when other users may not know the answer to a particular question.
I’m familiar with Apple’s historical MPEG-based container usage, going back to the early days of QuickTime. And I’m aware of the difference between remuxing and transcoding. (I use MKVToolNix and HandBrake almost every day.)
What I didn’t know - which actually makes sense now that I think about it - but is nonetheless disappointing…is that Plex doesn’t use its own client-side video engine. Of course the reason for this is because the overall design is for universal compatibility, since Plex is on so many platforms. I get that - I just didn’t think of it that way until now.
That leads me to wonder - why doesn’t Plex enhance client software with a real video engine on the small number of popular, powerful TV platforms? (Apple TV 4K, Android TV/Amazon 4K devices, and Roku 4K devices. Maybe PC/Mac clients.) Essentially, as far as OTT boxes, those are the MAIN three.
VLC and Infuse natively accept MKV containers and therefore do not qualify as valid defining criteria. ( I use both apps. I also only use MKV files )
I understand that now - you’re right.
Try to import MKV into your iDevice and play with the native player (not an app).
Repeat the sequence with a MP4 and observe proper playback.
I believe it - I’m sure that’s why the Apple TV release only said “Add direct play support for HEVC video codec.” Even the word codec, as opposed to container, was specifically used. End of discussion on Apple TV.
BUT - what about my TiVo Bolt, for which the release notes EXPLICITLY state support for UHD (standardized on HEVC codec) in both MP4 and MKV containers. Why is that remuxing my HEVC MKVs?
That brings up an even more important question - why can’t PMS for the the super-powerful Nvidia Shield smoothly remux / transcode my HEVC / non-AC3 videos for playback on the Apple TV 4K or TiVo Bolt anyway? (even though it shouldn’t be trying the remuxing portion on the TiVo)
My entire house is run with Cat 6 Ethernet and gigabit switches, and I’m only talking about local playback - not expecting miracles on the go of course.
I handle PMS on Linux and NAS boxes. I can’t speak to any of the players.
You will probably be better served asking there or I can move this thread wherever you’d like.
Gotcha. I have a post under Smart TVs (LG, 2016+ Samsung, Sony, TiVo, Toshiba, VIZIO) in the Community Forums. The reason I posted here in the Plex Pass forum is because I didn’t get far there.
Whatever you think is best - Priority 1 is finding out why PMS remuxes to TiVo, contrary to release notes.
The lagging Shield I can worry about another time.
May I see:
- XML of the file you are attempting to play (Hover over item -> Get Info -> View XML)
- The full set of logs (ZIP file) captured immediate after you attempt to play the file? (Settings - Server - Help - Download Logs )
- Type of system, with CPU model, you are running the on
Thank you, Chuck.
I’ve attached the XML data from the title that I will use as an example, an MKV containing HEVC / Atmos tracks. (Not concerned about the audio - I’m already aware of the EAC3 limitation on the Apple TV.) I’ve also zipped and attached the logs after playing the video for about 2 minutes. The server handled the remuxing without skipping for a bit, but of course the goal is Direct Play.
Your 3rd request was cut off, it appears. Let me know if there is anything else that you need.
My Plex Media Server:
Version 1.9.7.4460
1st Gen Nvidia Shield
CPU: Nvidia’s Tegra X1 system-on-chip, based the ARM Cortex-A57 CPU
and Nvidia’s Maxwell microarchitecture GPU
3GB RAM
The Plex Client in Question:
Plex for TiVo version 3.13.7
TiVo Bolt 500GB Model TCD849500
CPU: Broadcom BCM7449 21000 Dhrystone MIPS
3GB RAM
From your XML
<Media videoResolution="1080" id="14361" duration="7097007" bitrate="6783" width="1920" height="802" aspectRatio="2.35" audioChannels="8" audioCodec="truehd" videoCodec="hevc" container="mkv" videoFrameRate="24p" videoProfile="main">
<Part accessible="1" exists="1" id="14361" key="/library/parts/14361/1511412063/file.mkv" duration="7097007" file="/storage/LIBREELEC/Media/Movies/file.mkv" size="6017576460" container="mkv" hasThumbnail="1" videoProfile="main">
<Stream id="23855" streamType="1" default="1" codec="hevc" index="0" bitrate="6783" language="English" languageCode="eng" bitDepth="8" chromaSubsampling="4:2:0" colorRange="tv" colorSpace="bt709" frameRate="23.976" height="802" level="120" profile="main" refFrames="1" width="1920" />
<Stream id="23856" streamType="2" selected="1" default="1" codec="truehd" index="1" channels="8" bitrate="4603" language="English" languageCode="eng" audioChannelLayout="7.1" bitDepth="24" samplingRate="48000" />
<Stream id="23857" streamType="3" selected="1" codec="pgs" index="2" bitrate="53" language="English" languageCode="eng" headerCompression="1" />
</Part>
</Media>
I don’t think the Tivo handles bitmapped (PGS) subtitles natively. I believe it handles SRT/ASS/SSA (Text subtitles) but doesn’t handle bitmaps. Bitaps traditionally need to be fused (burned in) to the base video image. Doing this definitely needs the transcoder.
OK, so I had subtitles set to come on automatically, but I had no problem turning that off. (Setting it to manual select.)
And this definitely stopped the video from remuxing!
However - it also stopped video altogether - so when it says “Direct Stream,” there is just a black screen:
“The Hitman’s Bodyguard” demonstrated this symptom, so I tested using “Gravity.”
Paused for a moment to show the menu items while in play mode.
After I pressed play and waited a few minutes. 
The blank video has been seen if the file hasn’t been tagged with the FourCC code of “hvc1” on AppleTV.
HEVC content works to the AppleTV, but the media must follow some very specific guidelines.
It must be in an MP4 container.
The resolution must not be greater than 3840 × 2160.
If the video codec is HEVC, the FourCC must be hvc1.
The audio must be in a format native to the Apple TV (AAC, AC3, E-AC3, MP3).
The subtitles must be in an Apple TV compatible format (text based (mov_text, tx3g, ttxt, text), PGS will not work).
In the Plex client you may need to set the Video Quality for Home (and possibly Internet) to Maximum, as 20Mb (which was the default until yesterdays update) will probably not be enough for 4K files.
If all of the above is not met, the server will transcode it to 1080p/h264.
Thanks for the response. I previously didn’t grasp the concept that Plex didn’t have a client side video engine like many other apps that play MKVs on Apple TV. We had discussed that and decided to move onto Plex for TiVo.
Plex for TiVo gained explicit support for UHD via MP4 or MKV back on 6/22/17. We had just figured out how to make PMS Direct Stream the HEVC portion of the MKV container (subtitles off) and I was thinking it was all fixed because it was no longer transcoding (technically remuxing).
BUT…of course it couldn’t be simple. I’ve only spent 3 days trying to solve a stupid problem that Plex explicitly says shouldn’t be a problem…being served from one of the most powerful PMS server devices you could desire that isn’t a high end PC.
The Direct Streaming Video was just Black. (On the TiVo Bolt) Plex is like whack a mole to me at this point. Solve one problem and another inevitably pops right up.
