4k video file getting transcoded

[martincjose]

Hello,

Jellyfin server hardware: Old laptop with Intel Core i7-3740QM CPU with NVIDIA Quadro K2000M (HW transcode disabled)
Jellyfin server: v10.11.6 

TV: LG 4k 65" OLED with DolbyVision/HDR/HDR10+, etc
Player hardware: Amazon Fire TV Stick 4k (2nd generation)
Jellyfin client: 0.19.7

I have a 4k video file that is being transcoded when trying to watch on the above hardware.  The CPU is not able to keep up and the video buffers with the transcoding and it seems the HDR information is getting stripped and only SDR is displayed.  My question is, why is the video getting transcoded when the hardware is able to play the file directly?  As a test, I was able to play the file using Kodi without any buffering.  So it is clear the Amazon Fire TV 4k and the TV are able to play the file.

I would like to use Jellyfin instead of Jellyfin and Kodi.  Any help anyne can provide would be appreciated.

Thanks

Following are the specs of the file:

Video
ID                                      : 1
Format                                : HEVC
Format/Info                          : High Efficiency Video Coding
Format profile                       : Main 10@L5@Main
HDR format                          : Dolby Vision, Version 1.0, Profile 8.1, dvhe.08.06, BL+RPU, no metadata compression, HDR10 compatible / SMPTE ST 2094 App 4, Version HDR10+ Profile B, HDR10+ Profile B compatible
Codec ID                              : V_MPEGH/ISO/HEVC
Duration                               : 2 h 16 min
Bit rate                                : 19.4 Mb/s
Width                                  : 3 840 pixels
Height                                 : 2 080 pixels
Display aspect ratio               : 1.85:1
Frame rate mode                  : Constant
Frame rate                           : 23.976 (24000/1001) FPS

[theguymadmax]

Each is going to have it own capabilities, so just b/c something direct plays on one doesn't mean it will on another.

The Fire TV Stick has a nasty bug where it can't play videos with hybrid metadata (both DV and HDR10+). This is partially solved in the current Jellyfin client by remuxing the video, otherwise it wouldn't play at all.

And LG TVs is just a nightmare to get DV working correctly. There are countless threads on GitHub relating to that - that's something I don't even bother with.

[martincjose]

Thanks for the reply. Just to be clear, both Jellyfin and Kodi are running on the Fire Stick (HDMI port). LG TV is just used as a monitor. So if Kodi is able to play the video without transcoding, shouldn't Jellyfin also be able to play without transcoding? What is making Jellyfin think it needs to transcode?

Thanks

[theguymadmax]

Kodi running on the Fire TV does not equal Jellyfin for the Android TV client. They are different software, you're making a false assumption here, that just b/c it works on one, it should work on the other. 

See an older post of mine describing workarounds for that bug (before the current fix of remuxing the video). For compatibility reasons, I would recommend removing HDR10+ metadata from those hybrid files. 

https://forum.jellyfin.org/t-problem-pla...on-fire-tv

[34626]

As an alternative to a Fire Stick 4k i would recommend a Raspberry pi 5 + LibreElec + addon Jellyfin / JellyCon
I just select the movie on my smartphone and choose the Raspberry pi device and it plays great :-)
LibreElec (Kodi) also offers so much more you can do.

[martincjose]

OK, I understand now. Thank you for clarifying. I used the ffmpeg command from the post and created two files, one with HDR10+ and one with DV. The HDR10+ picture seemed to be brighter (maybe too bright) while the DV brightness was more muted. Why do you suggest removing HDR10+ metadata and not DV? What is the compatibility issue?

As a side question, why is the file with the HDR10+ or DV metadata removed larger by about 200MB?

Regarding using RP5, I would love to do it but I don't think my wife would not be happy.

Thanks

[theguymadmax]

Compatibility issue, I meant removing HDR10+ from hybrid media that contain both DV and HDR10+ for devices that have issues with it (such as the Fire TV Stick). You can also do the opposite, remove DV and keep HDR10+. 

They are competing standards, and some people prefer one over the other. Not trying to debate which one is better. It's up to you. I prefer to keep DV, as I have a Dolby Vision TV. Also, the DV 8.1 profiles include HDR fallback for non-Dolby Vision-enabled displays.