Server Version#: 1.22.1.4228
Player Version#: 8.13.2.23227 and 8.14.0.23432
NVIDA Shield Pro as the PMS
Fire TV Stick 2nd-gen (local network)
Fire TV 3rd-gen (remote network)
Unfortunately I can’t play or transcode 4k HEVC files from my media server on Fire TV devices.
I can play the same files ok on an iPhone, MacOS, and on the Shield Pro Plex Client (version 8.15.0.23855)
I’ve disabled IPv6 on PMS.
The issue only occurs on FireTV devices.
Thanks for your help!
The Shield may not be powerful enough to transcode 4K HDR video in real time, especially if HDR to SDR tonemapping is required. HDR to SDR Tonemapping is performed in software on the Shield. It cannot take advantage of hardware acceleration (using the GPU).
The FireTV Stick 2nd Gen does not support 4K video (Fire TV device Specifications).
You’ll need a FireStick 4K to direct play 4K HDR video. A FireTV Cube 2nd gen may work as well, based on its specifications.
Regarding the remote location:
Successful remote playback depends on available bandwidth. Both the uplink speed at the server location and the downlink speed at the remote client must have enough bandwidth to handle a 4K stream.
You will also need a 4K HDR capable client. I’m not sure if the Fire TV 3rd Gen (pendant) can play 4K HDR video. I have a 1st gen cube, which has similar specifications, and it cannot playback HDR video via Plex (despite the specifications showing HDR10 support).
You can monitor playback via Plex Dashboard → Now Playing. It will show if the media is direct playing, direct streaming, or transcoding.
This thread has useful information regarding playback of 4K video using Plex: [INFO] Plex, 4k, transcoding, and you - aka the rules of 4k
Thanks @FordGuy61, that was a very useful reply!
That’s a fair point, I hadn’t fully checked if the Shield Pro 2019 could transcode 4k files, and useful to know about HDR to SDR software decoding! I’ll do some test transcoding to my other non-fire tv devices to see if that’s the issue.
Yep, I was expecting this to transcode, so it may be due to the realtime 4k transcoding you mention. Looking at the logs though it seems to give a decoder error on the client side?
03-31 11:25:30.753 e: [ExoPlayer][EventLogger] playerFailed [eventTime=89.57, mediaPos=0.00, window=0, period=0
com.google.android.exoplayer2.ExoPlaybackException: MediaCodecVideoRenderer error, index=1, format=Format(0, null, null, video/avc, h264, 18791000, null, [3840, 2160, 0.0], [-1, -1]), format_supported=NO_EXCEEDS_CAPABILITIES
Caused by: com.google.android.exoplayer2.mediacodec.MediaCodecRenderer$DecoderInitializationException: Decoder init failed: OMX.MTK.VIDEO.DECODER.AVC, Format(0, null, null, video/avc, h264, 18791000, null, [3840, 2160, 0.0], [-1, -1])
Useful link, thanks! Interestingly though, the first paragraph says the following, so fingers crossed my transcode test to other devices works ok.
I changed the settings on my iPhone Plex so that Home Streaming was using 10Mbps, 1080p HD, and whilst it at least started playing the film, it kept pausing/buffering, with a message saying something like “the server is not powerful enough to convert this video”, so that is certainly part of the blame.
Interestingly, when I try to play back video from either FireTV device, the Dashboard doesn’t show the playing movie at all, whereas the test I just did with the iPhone at least showed the transcoding status shown above. Could this point to it being a client issue?
My next test will be the remote 4k Fire TV device. My internet upload speed is 35Mb and I’ll ensure the Plex settings are set to direct play for remote media. 
I’ll grab logs from this device too.
SOLVED!
So yes, Shield TV Pro is the culprit here. It basically can’t do HW Transcoding of 4K HEVC movies.
I installed PMS on my Ubuntu Linux Docker server (direct install, not as a container) which is an Intel 8th-gen Coffee-Lake NUC box (Core i3-8109). Given that this CPU can easily do H/W transcoding (as well as H/W HDR to SDR Tone Mapping), I realised this would be a much better server than the Shield.
I can now successfully transcode high bitrate source 4K HEVC files into 1080p on the two Fire-TV devices without any issues! 
Thanks for your help @FordGuy61, it set me on the right path.
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.
