4k video stutters on mi box s

[Maciejuszko]

Hi guys. I am new to jellyfin. I have set up my initial media server on Macbook Air m1 256/8gb. So far it works great, playing all media I have collected on all of my devices.

Trying to play the Fallout series on my Mi Box S is where the problems start. All of the 1080p media playback on this device with no issue, but this show in particular cant playback smoothly - it stutters every 15 seconds, then buffer for 10 seconds and play again, then repeat, making it unwatchable.

These movies are previously transcoded in handbrake to preset compatibile with Android TV: H265 10bit HEVC (using toolbox), 4k. The Fallout playback is smooth on all of my other devices except for Mi box s, which is painful beacuse this is my primary media device.

Mi box S is connected by wifi, the show is streamed from Macbook listed above also via wifi. 
Jellyfin version is 10.9.9. During playback there is an information about Mi box "this media is played without remixing". 
4k videos playback works smoothly on other devices, so I doubt that wifi bandwith is the issue.

What should I check and do to solve this issue?

Best regards

[TheDreadPirate]

Can you share your full jellyfin logs via pastebin? And what model Mi Box is it? Is "Mi Box S" the full model name?

[Maciejuszko]

Of course.
Here are the full logs from this launch: https://pastebin.com/DF7HBmZC
The specific Mi Box model is "mitv-afkr0".

[TheDreadPirate]

Can you share the media info for some of the files you are having issues with?

   

The log isn't showing any transcoding, so this is either a client issue or network issue. Depending on how chunky the file is.

[Maciejuszko]

Of course, here is the media info:
Fallout mi box
Container: mp4
Path: /Volumes/SSDWD 1TB-1/Seriale/Fallout (2024)/Season 01/Fallout mi box.mp4
Size: 6092 MB

Video
Title: 4K HEVC SDR
Codec: HEVC
Codec tag: hvc1
AVC: No
Profile: Main 10
Level: 150
Resolution: 3840x1604
Aspect ratio: 2.40:1
Anamorphic: No
Interlaced: No
Framerate: 24
Bitrate: 11196 kbps
Bit depth: 10 bit
Video range: SDR
Video range type: SDR
Colour space: bt709
Colour transfer: bt709
Colour primaries: bt709
Pixel format: yuv420p10le
Ref frames: 1

Audio
Title: Surround - English - AAC - 5.1 - Domyślne
Language: eng
Codec: AAC
Codec tag: mp4a
AVC: No
Profile: LC
Layout: 5.1
Channels: 6 ch
Bitrate: 157 kbps
Sample rate: 48000 Hz
Default: Yes
Forced: No
External: No

Subtitle
Title: Polish - Domyślne - MOV_TEXT
Language: pol
Codec: MOV_TEXT
Codec tag: tx3g
AVC: No
Resolution: 3840x240
Bitrate: 0 kbps
Default: Yes
Forced: No
External: No

Subtitle
Title: English [SDH] - MOV_TEXT
Language: eng
Codec: MOV_TEXT
Codec tag: tx3g
AVC: No
Resolution: 3840x240
Bitrate: 0 kbps
Default: No
Forced: No
External: No

[TheDreadPirate]

That's a pretty ordinary file and from the spec sheet your Mi Box should be able to handle no problem.

Is the WiFi signal weak where the Mi Box is located?

[Maciejuszko]

I think the WiFi signal is enough, as I can stream HBO & Netflix 4k with no issue on Mi Box.
I have transcoded the Fallout episode to the same file format just lower bitrate - from 11196kbps to 7297kbps. The playback still stutters.

I also tried to playback another movie in 4k:

Indiana Jones And The Last Crusade (1989)
Container: mkv
Path: /Volumes/SSDWD 1TB-1/Filmy HD/Indiana Jones And The Last Crusade (1989).mkv
Size: 6155 MB

Video
Title: 4K HEVC SDR
Codec: HEVC
AVC: No
Profile: Main 10
Level: 150
Resolution: 3840x1632
Aspect ratio: 2.35:1
Anamorphic: No
Interlaced: No
Framerate: 23.976025
Bitrate: 6781 kbps
Bit depth: 10 bit
Video range: SDR
Video range type: SDR
Pixel format: yuv420p10le
Ref frames: 1

Audio
Title: English - AAC - 5.1
Language: eng
Codec: AAC
AVC: No
Profile: LC
Layout: 5.1
Channels: 6 ch
Bitrate: 476 kbps
Sample rate: 48000 Hz
Default: No
Forced: No
External: No

Despite the almost similar bitrates, this one does not stutter at all.

[TheDreadPirate]

You can try repackaging the problem file.

Code:

/usr/lib/jellyfin-ffmpeg/ffmpeg -fflags +genpts+igndts -i "/path/to/problem/file.mp4" -map 0 -codec copy -max_muxing_queue_size 2048 -avoid_negative_ts make_zero -max_interleave_delta 0 newFile.mp4

[Maciejuszko]

I think the internet connection is the real issue:
- When putting on other media with bitrate >8000kbps stil stutters
- When puttin on Fallout transcoded to bitrate <7000kbps the playback is smooth
- When limiting transmission speed in client to 10Mbps the playback is smooth (playing the original 11196bps file).

Given these circumstances, I belive strenghtening WiFi signal or connecting via Ethernet are the only solutions to my problem

Thanks for all help