SOLVED: Jitter/stuttering with Direct Play on some videos

[Tom Haddon]

Hi,

I've recently downloaded some videos with yt-dlp from https://www.arte.tv/ and they're displaying some jitter/stuttering even though there's no transcoding happening.

The jellyfin server is running on Ubuntu 24.04. I've installed via the jellyfin repos:

Code:

$ dpkg -l | grep jellyfin
ii  jellyfin                                        10.11.1+ubu2404                          all          Jellyfin is the Free Software Media System.
rc  jellyfin-ffmpeg5                                5.1.3-1-jammy                            amd64        Tools for transcoding, streaming and playing of multimedia files
ii  jellyfin-ffmpeg7                                7.1.2-3-noble                            amd64        Tools for transcoding, streaming and playing of multimedia files
ii  jellyfin-server                                  10.11.1+ubu2404                          amd64        Jellyfin is the Free Software Media System.
ii  jellyfin-web                                    10.11.1+ubu2404                          all          Jellyfin is the Free Software Media System.
$ cat /etc/apt/sources.list.d/jellyfin.sources
Types: deb
URIs: https://repo.jellyfin.org/ubuntu
Suites: noble
Components: main
Architectures: amd64
Signed-By: /etc/apt/keyrings/jellyfin.gpg

Here's the media info for one of the videos that's stuttering:

Code:

S01E01
Container: mp4
Path: /srv/jellyfin/..../Season 1/S01E01.mp4
Size: 1.6 GiB

Video
Title: 1080p H264 SDR
Codec: H264
Codec tag: avc1
AVC: Yes
Profile: High
Level: 41
Resolution: 1920x1080
Aspect ratio: 16:9
Anamorphic: No
Interlaced: No
Framerate: 25.000387
Bitrate: 4968 kbps
Bit depth: 8 bit
Video range: SDR
Video range type: SDR
Pixel format: yuv420p
Ref frames: 1
NAL: 4

Audio
Title: AAC - Stereo - Default
Language: und
Codec: AAC
Codec tag: mp4a
AVC: No
Profile: LC
Layout: stereo
Channels: 2 ch
Bitrate: 189 kbps
Sample rate: 48000 Hz
Default: Yes
Forced: No
External: No

I can't see any substantial difference between this and another video that I've downloaded from a partner organisation but isn't displaying any jitter/stuttering. However, it seems this jitter/stuttering happens with any videos I download from Arte. If I play the video on the same machine that jellyfin is running but using VLC (i.e. not using jellyfin) it plays fine. The two clients that I've used that are displaying these symptoms are the web client (running on the same machine as jellyfin) and an Android TV on my local network.

As I say, I've checked the logs and there's no transcoding happening.

Any help appreciated. Thanks.