Dolby Vision resume on LG webOS triggers DV mode but playback stays frozen at --:-- / no video or audio

[GiacomoCunardi2005]

Bug description

When playing a Dolby Vision movie on the Jellyfin LG webOS app, playback works correctly if I start the movie from the beginning.

The issue happens when I stop playback and later try to resume from the saved position.

On resume:

• the TV triggers Dolby Vision mode correctly; I can see the Dolby Vision notification in the top-right corner of the TV;
• however, no video is displayed;
• no audio starts;
• the playback timer initially shows --:--;
• playback does not actually start from the saved position.

If I press pause and then play again:

• the playback timer finally loads;
• subtitles also load;
• but video and audio still do not start;
• the timer remains frozen and does not advance.

If I choose “Play from beginning” instead of resuming, the same file starts normally and plays correctly.

So the file itself can be played by the LG webOS app. The failure appears to be specific to resume / saved-position initialization with Dolby Vision content.

---

Reproduction steps

1. Open Jellyfin on an LG webOS TV.
2. Start a Dolby Vision movie.
3. Let it play normally from the beginning.
4. Stop playback after some time.
5. Go back to the same movie and choose Resume / Continue watching.
6. Dolby Vision mode activates on the TV, but the player does not show video and the timer remains --:--.
7. Press pause and then play again.
8. The timer and subtitles load, but video and audio do not start and the timer stays frozen.
9. Go back and choose Play from beginning.
10. The movie starts normally.

---

Expected behavior

The movie should resume from the saved position with Dolby Vision enabled, with video, audio, subtitles and playback timer all working.

---

Actual behavior

Dolby Vision mode is activated by the TV, but playback does not start correctly:

• no video;
• no audio;
• timer initially shows --:--;
• after pause/play, timer and subtitles load;
• playback remains frozen;
• timer does not advance;
• starting from the beginning works.

---

Important observation

This is not a general Dolby Vision playback failure.

The same file starts correctly from the beginning and Dolby Vision is triggered correctly by the TV.

The broken case is specifically resume / continue watching from a saved position.

---

Playback settings tested

I tested the following LG webOS playback options:

• Prefer fMP4-HLS Media Container: ON and OFF
• Shorter HLS segments: ON and OFF

These settings did not change the behavior.

I also tested fMP4-HLS with 1-second HLS segments. The issue still happens.

Changing the selected audio track does not change the issue either. I tested different audio tracks, including DTS-HD MA, E-AC-3, and AC-3 tracks. The resume behavior remains the same.

Full video transcoding makes resume work, but I do not want to use video transcoding because I want to preserve HDR / Dolby Vision.

---

Server / client versions

• Jellyfin Server: 10.11.8
• Jellyfin Web: 10.11.8
• Client: Jellyfin for WebOS
• webOS app version from server logs: Jellyfin for WebOS 1.2.2
• Main TV model: LG OLED55BX6LB
• Main TV software version: 04.63.25
• Main TV manufactured: 12/2020

---

Cross-test on another LG webOS TV

I also tested the same file on another LG webOS TV:

• Model: LG 55UN81006LB
• webOS version: 5.6.1-6
• Device name: [LG] webOS TV UN81006LB

On this TV the file plays, but it starts as HDR instead of Dolby Vision.

This TV appears to be using the HDR10 fallback path rather than the Dolby Vision playback path.

This is useful because the problematic behavior only happens on the Dolby Vision-capable LG OLED55BX6LB when Dolby Vision mode is actually triggered. On the second LG TV, where the same file plays as HDR instead of Dolby Vision, playback works.

I do not currently have another external HDR/Dolby Vision capable client to compare against, such as Apple TV, Nvidia Shield, Android TV, or another external player. I can only test with LG webOS TVs.

---

Server log details

The server logs show that Jellyfin is not doing a full video transcode in this case.

It is doing an HLS fMP4 remux with both video and audio copied:

/usr/lib/jellyfin-ffmpeg/ffmpeg
-analyzeduration 200M
-probesize 1G
-fflags +genpts
-f matroska
-i file:"/data/movies/Se7en (1995)/Se7en (1995) Bluray-2160p.mkv"
-map_metadata -1
-map_chapters -1
-threads 0
-map 0:0
-map 0:4
-map -0:s
-codec:v:0 copy
-tag:v:0 dvh1
-strict -2
-bsf:v hevc_mp4toannexb
-start_at_zero
-codec:a:0 copy
-copyts
-avoid_negative_ts disabled
-max_muxing_queue_size 2048
-f hls
-max_delay 5000000
-hls_time 1
-hls_segment_type fmp4
-hls_fmp4_init_filename "b2dcd3f4eb998ffa68e101f248bc6bbe-1.mp4"
-start_number 0
-hls_segment_filename "/transcodes/b2dcd3f4eb998ffa68e101f248bc6bbe%d.mp4"
-hls_playlist_type vod
-hls_list_size 0
-hls_segment_options movflags=+frag_discont
-y "/transcodes/b2dcd3f4eb998ffa68e101f248bc6bbe.m3u8"

---

### Server environment

- Deployment: Docker
- Docker image: `lscr.io/linuxserver/jellyfin:latest`
- Host OS: Debian
- Hardware acceleration: Intel Quick Sync / `/dev/dri` passed to container
- Network: local LAN

---

### Media information

Affected file tested:

```text
Path: /data/movies/Se7en (1995)/Se7en (1995) Bluray-2160p.mkv
Container / format: Matroska / WebM
Duration: 7614.69 seconds
Size: 44,919,561,042 bytes
Bitrate: 47,192,530 bps

[superdare]

Hello,
I have the same problem on a brand new tv LG oled C5 when watching dolby vision .mkv files and they all require remuxig. The playback will stays forever frozen after few seconds or few minutes of playing. Yes, in this case, I'm using Jellyfin app from LG Store version 1.2.2 (everything elese is up-to-date). When watching the same dolby vision .mkv file(s) with LG media player or LG browser everything works w/o problems. I tried every combination of options and in the end the result will be the same = freeze playback.

When playing using Jellyfin app:
Message from Jellyfin Dashboard:
"The media is in an incompatible file container (MKV, AVI, WMV, etc) but both the video stream and audio stream are compatible with the device"

And some errors from logs:

[2026-06-01 12:22:48.541 +03:00] [INF] [34] Emby.Server.Implementations.Session.SessionWebSocketListener: Sending ForceKeepAlive message to 1 inactive WebSockets.
[2026-06-01 12:23:48.342 +03:00] [ERR] [35] Microsoft.AspNetCore.Server.Kestrel: Unexpected exception in TimingPipeFlusher.FlushAsync. System.Net.Sockets.SocketException (10022): An invalid argument was supplied. at System.IO.Pipelines.Pipe.GetFlushAsyncResult() at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure.PipeWriterHelpers.ConcurrentPipeWriter.FlushAsyncAwaited(ValueTask1 flushTask, CancellationToken cancellationToken) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure.PipeWriterHelpers.TimingPipeFlusher.TimeFlushAsyncAwaited(ValueTask1 pipeFlushTask, MinDataRate minRate, IHttpOutputAborter outputAborter, CancellationToken cancellationToken)

Thank you!

[Valnjes]

Works on LiteFin:
https://github.com/MoazSalem/litefin/