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Lag between audio/video with latest versions
Posted: Thu Feb 26, 2026 2:04 pm
by septembergurls
I've noticed this over the last couple of months. When I copy something from my Mac Mini to my PS3 over an ethernet, some copy perfectly. But with others, there is a 1-3 second lag between audio and video that makes it unwatchable. I tried to downgrade to previous versions of UMS that I knew worked fine, but with the new Mac Mini, I get the "unable to load JRE" error. Downloading new Java seems useless.
Forgive me if this has been discussed before. I tried to search the forum but didn't see it. UMS may be the greatest piece of software I own, and I have to get this fixed. Any thoughts, hivemind?
Re: Lag between audio/video with latest versions
Posted: Thu Feb 26, 2026 2:48 pm
by septembergurls
I have added the debug file here. This problem is popping up on almost everything I copy over now.
Re: Lag between audio/video with latest versions
Posted: Thu Feb 26, 2026 11:00 pm
by mik_s
Audio/video sync problems is usually down to using MEncoder for the transcoding engine.
I don't know why this has these problems though.
I can see that it should be using FFmpeg but is switching to MEncoder because of a setting with subtitles.
This is not set in your configuration but the default setting is true
Code: Select all
# Defer to MEncoder when transcoding subtitles
# --------------------------------------------
# Whether FFmpeg should defer to MEncoder when there are subtitles that need
# to be transcoded.
# Both engines can handle subtitles, but MEncoder is more stable right now.
# Default: true
ffmpeg_mencoder_problematic_subtitles =
Turning this option off should fix it so it will just use FFmpeg.

- Screenshot 2026-02-26 104213.png (32.32 KiB) Viewed 193859 times
I think the main reason for this option is because FFmpeg can take a little longer to start up if it has to parse subtitles so the device can timeout before it gets the video data.
If this happens, playing again immediately should work as the subs have been cached so starts faster.
There has been some issues we have been trying to track down with transcoding stopping after a few seconds on some devices and I think one report of this happening was on the PS3.
If this starts to happen I suggest using an older version till this is fixed.
I have tracked the problem down to version 14.7.0 for the devs to figure out why it is happening, so try the version before this.
Re: Lag between audio/video with latest versions
Posted: Fri Feb 27, 2026 3:29 am
by septembergurls
Are you able to help me dowload and use that version? i had to upgrade to a Mac Mini from my old iMac, and now any time I try to download an older version of UMS, i get the "unable to load Java Runtime Environment" the second i try to open it. any thoughts on how to get around that?
and thank you so much for your reply.
Re: Lag between audio/video with latest versions
Posted: Fri Feb 27, 2026 2:23 pm
by mik_s
Did changing that setting work but you have problems with it stopping early?
You can get previous releases from Github
here
I suggest doing a clean install to avoid conflicts due to changes in the database structure.
This should also install a contained java runtime just for UMS so is not something you need to install separately.
You could make a backup of you current configuration folder in case you want to restore it in the future.
I don't know where it is on a Mac but it should be "/Users/jodycallahan/Library/Application Support/UMS/" going by what is in your logs.
Re: Lag between audio/video with latest versions
Posted: Fri Feb 27, 2026 4:13 pm
by septembergurls
I just turned that setting off and will let you know if it works. Thank you for that suggestion.
And forgive me for being dense. I clicked on the github link you posted and navigated to the 14.6 version...but i don't see a download link.
Re: Lag between audio/video with latest versions
Posted: Fri Feb 27, 2026 10:30 pm
by mik_s
You might have to click the Assets link to expand that section. I think it auto collapses them on older releases where there are many files.
Re: Lag between audio/video with latest versions
Posted: Sun Jul 26, 2026 9:59 pm
by Gaston62
Same problem than septemgurls here.
Streaming from my Win10 PC to my good old PS3, and since probably more than 1 or 2 years, I see lag between sound and video (especially on mkv files, I think).
By curiosity, I reversed back to the oldest UMS version I have kept stored on my PC (9.8.3), and... problem gone !!! Works perfectly !!!
Now, maybe, when and if I have time (some things IRL take me lots of time : I am about to move from Switzerland to Thailand in a few weeks, and I live in boxes and luggages, if you see what I mean...), I should progressively test more recent version until I find the one which in which the problem appears first.
Re: Lag between audio/video with latest versions
Posted: Sun Jul 26, 2026 11:49 pm
by mik_s
Check that defer to Mencoder option, I think it defaults to on in recent versions where it was previously off.
If you had not changed it it will use the default value.
The logs will show if it is transcoding using FFmpeg or Mencoder.
Re: Lag between audio/video with latest versions
Posted: Thu Jul 30, 2026 9:46 pm
by Gaston62
I have jumped from 9.8.3 to 13.4.0. As I remember I have these lag problems since 3 years (and they got worse since), I will stay on this version, which works perfectly and without hassles for me.