Sound out of sync

[gluk147 6]

Hi everyone.
Any ideas what the problem might be?
Emby Server version 4.10.20.
For playback, I tried the Emby Android and Emby for Android TV apps—the latest versions from the Google Play Store.

I tested about six different movies; all used the AV1 video codec and Dolby Atmos TrueHD audio.
In all cases, the streaming boxes were connected directly to a Samsung HW-930F soundbar.

The boxes I tested were the Xiaomi Mi Box 3, Ugoos SK-01, and Homatics Box 4R; the problem was the same on all of them. Between the 55- and 65-minute mark, a severe audio-video desync occurs (a lag of about 2 seconds).
If I watch the same movies on the Google TV Streamer, there are no such issues—though that device doesn't output TrueHD audio.

The problem only occurs in the Emby apps; everything works perfectly via Vimu and Kodi.

I checked the server logs, but there are no errors.

[Luke 43167]

 

Hi there, let's look at an example. Please attach the information requested in how to report a media playback issue. Thanks!

 

[gluk147 6]

To clear the logs, I restarted the server at 20:00 before the test.
I started playing the movie at 20:01.
The audio began to lag at approximately 21:00 (around the 58–59 minute mark).
Device: Xiaomi Mi Box 3.
I am attaching the server logs and information about the video file.

2026-07-28 21:00:29.440 Info SessionManager: Playback progress (Pause)
I stopped playback myself at that point, after the lag had started.

embyserver.txt hardware_detection-63920865587.txt Супермен 2025 (TrueHD Atmos).mkv.MediaInfo.txt

Edited July 28 by gluk147

[Luke 43167]

OK we'll take a look at it. Thanks.

[gluk147 6]

Hi everyone,

I’m facing a persistent audio-video synchronization issue with Dolby TrueHD Atmos tracks in the official Emby for Android / Android TV app, and I wanted to share logs and details to help track it down.

The Problem:

• When playing media with a Dolby TrueHD Atmos audio track (bitstreamed/passthrough), the audio and video lose sync gradually.

• The desync starts to become noticeable right around 54–55 minutes into playback (drifting by about 2 seconds).

• If I jump backward by 10 seconds, the sync temporarily recovers, but the drift continues over time.

• Other players work fine: Playing the exact same files through Kodi or ViMu Player on the same hardware has zero sync issues.

Scope & Environment:

• Issue reproduced on 4 different devices: Ugoos AM9 Pro, Xiaomi Mi Box 3, Homatics Box R 4K Plus, and Ugoos SK1. The behavior is identical across all of them.

• Emby for Android version: Latest version from the Google Play Store.

• Emby Server version: 4.10 Beta.

• Audio Setup: Bitstream (Passthrough) via HDMI to a Dolby Atmos-compatible soundbar (Samsung HW-Q930F).

What the Logs Show: I captured a debug log during playback using ADB: adb logcat -v time | grep -i -E "emby|exoplayer|audio|codec|video" > emby_debug_logs.txt

Looking into the logs around the desync point, the system audio HAL shows regular adjustments, and we can spot warnings from AudioTrack such as: W/AudioTrack: getTimestamp_l: retrograde timestamp position corrected

It seems that during long playback sessions of heavy TrueHD Atmos streams, the ExoPlayer / Android MediaCodec passthrough pipeline slowly loses precise PTS alignment, whereas other media players handle this seamlessly.

I have attached the debug log files to this post. Any insights, workarounds, or fixes from the dev team would be greatly appreciated!

Thanks,

emby_debug_logs.txt