Lip sync problems.

[yocker 1247]

Hello.

I have friend with a Samsung TV that has access to my server.
He has terrible lip sync problem with every thing he watches from my server, sadly i can't give specifis other than that since he lives far away from me so all i can ask i for suggestions for how what can help him with hes setup.

All i know is hes using a Samsung TV and eARC for hes soundbar. He tends to having to transcode most things he watches so maybe a transcoding problem?

[Luke 42077]

 

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

 

[yocker 1247]

We got it fixed some how, don't know how, the problem went away as soon as he contacted me about it.
We tried to recreated it but nothing did it, i'm not going to say no to an easy fix!

Many thanks though!

[yocker 1247]

@LukeWell.. I couldn't let it go after all and going through logs and replaying every video he has played the last couple of days, i think i found the problem.

It seems that files encoded with DTS-HD 7.1 (lower doesn't cause problems on Android at least) audio causes massive lip-sync problems on Samsung, on my Sony Android the video gets very choppy and later in the movie is replaced with lip sync problems as well.
Disabling DTS-HD passthrough in the Emby for Android TV fixes the problem and forces software decode, this is sadly not an option on the Emby standard app or on Samsung TV.

It doesn't seem to affect my Android phone.

Edited August 7, 2024 by yocker

[yocker 1247]

Forgot..

DTS-HD MA + DTS:X 7.1
Also seems like flac might be a problem for Samsung TV.

Edited August 7, 2024 by yocker

[FrostByte 5392]

Neither of those codecs (along with TrueHD and others) is supported by your friend's device and will cause transcoding and sometimes buffering when using the Samsung app more so than on some Android apps. High bitrate movies, slow network, slow server will of course make it worse.

For best results ask them to try and select an alternate audio track like AC3 or EAC3 before clicking PLAY whenever possible.  PGS subtitles is another which can cause bad buffering and preselecting text subtitles like srt will eliminate the need to transcode or burn-in those.   Doing that should help things.

They can check the charts in the back of the user's manual for a complete list of audio and subtitle formats compatible with Samsung.  Having eARC really doesn't play into it either because Samsung doesn't passthrough those HD audio formats from their TVs.

Here's an example of the charts in the back of the manual (there will be another for subtitles)

https://developer.samsung.com/smarttv/develop/specifications/media-specifications/2024-tv-video-specifications.html

 

@SamES not sure if you guys have seen this on the developer's page for next year's models, but may need to be converted starting with Tizen 9.0

Quote

The WMV, VC-1, and WMA codecs will no longer be supported on 2025 and later device models

 

 

 

 

[yocker 1247]

21 minutes ago, FrostByte said:

Neither of those codecs (along with TrueHD and others) is supported by your friend's device and will cause transcoding and sometimes buffering when using the Samsung app more so than on some Android apps. High bitrate movies, slow network, slow server will of course make it worse.

For best results ask them to try and select an alternate audio track like AC3 or EAC3 before clicking PLAY whenever possible.  PGS subtitles is another which can cause bad buffering and preselecting text subtitles like srt will eliminate the need to transcode or burn-in those.   Doing that should help things.

They can check the charts in the back of the user's manual for a complete list of audio and subtitle formats compatible with Samsung.  Having eARC really doesn't play into it either because Samsung doesn't passthrough those HD audio formats from their TVs.

Here's an example of the charts in the back of the manual (there will be another for subtitles)

https://developer.samsung.com/smarttv/develop/specifications/media-specifications/2024-tv-video-specifications.html

 

It's no problem to me if they get transcoded, if only the lip sync problem didn't happen. Server isn't breaking a sweat and hes on a good fiber line.
My Android TV as said can handle the flac but gets very choppy with DTS-HD MA + DTS:X 7.1 and he gets lip sync problems. A fix for me is disabling DTS passthrough in the Emby Android TV app but the setting is not present in the standard Emby Android app or in the Samsung one, will it be implemented?

Thanks for the link and suggestions, i will send it on to him.

[FrostByte 5392]

2 hours ago, yocker said:

I A fix for me is disabling DTS passthrough in the Emby Android TV app but the setting is not present in the standard Emby Android app or in the Samsung one, will it be implemented?

 

It's already on the list for the standard Android app for future implementation.  #29 on the list in the link below.

https://emby.media/community/index.php?/topic/89802-et-for-android-and-et-for-windows-ui-match-android-tv-app/

The whole reason for that option in ATV is because Android will convert DTSHD to PCM 2.0 if your hardware doesn't support DTSHD.  This may be a good thing for people who plug an Android box directly into a TV with no soundbar for instance.  By disabling passthrough in ATV it instead forces the server to convert DTSHD to AC3 5.1 (most people are going to prefer that over PCM 2.0). 

However, the Samsung app doesn't need to have that option because it never allows passthrough of DTSHD anyway.  The TV wouldn't know what to do with it since Samsung stopped paying for DTS encoder/decoder in all TVs starting in 2018 and just throws up an error message if you try to disable transcoding.  The reason you may have problems in Tizen more than Android is because Tizen can't handle the conversion from the server as well as Android.

It's up to you, but playback will always be smoother if you can have it direct play.  Plus, the server when transcoding always converts audio to AC3 384 kbps (see transcode logs on server).  The alternate audio in most files is AC3 640 kbps.  So, the audio quality will most likely be better too by direct playing.

Edited August 7, 2024 by FrostByte

[yocker 1247]

4 hours ago, FrostByte said:

It's already on the list for the standard Android app for future implementation.  #29 on the list in the link below.

https://emby.media/community/index.php?/topic/89802-et-for-android-and-et-for-windows-ui-match-android-tv-app/

The whole reason for that option in ATV is because Android will convert DTSHD to PCM 2.0 if your hardware doesn't support DTSHD.  This may be a good thing for people who plug an Android box directly into a TV with no soundbar for instance.  By disabling passthrough in ATV it instead forces the server to convert DTSHD to AC3 5.1 (most people are going to prefer that over PCM 2.0). 

However, the Samsung app doesn't need to have that option because it never allows passthrough of DTSHD anyway.  The TV wouldn't know what to do with it since Samsung stopped paying for DTS encoder/decoder in all TVs starting in 2018 and just throws up an error message if you try to disable transcoding.  The reason you may have problems in Tizen more than Android is because Tizen can't handle the conversion from the server as well as Android.

It's up to you, but playback will always be smoother if you can have it direct play.  Plus, the server when transcoding always converts audio to AC3 384 kbps (see transcode logs on server).  The alternate audio in most files is AC3 640 kbps.  So, the audio quality will most likely be better too by direct playing.

Nice! Really missing that option in the app!

That explains a lot, guess i will have to convert a couple of audio streams tonight.

Many, many thanks for the help!

Edit: I still don't understand why transcoding precisely those formats would cause lip sync problems for him as everything in the chain should be able to handle it. It doesn't matter though, will as said just re-encode the couple of files.

Edited August 7, 2024 by yocker

[FrostByte 5392]

If it still goes out of sync while it's direct playing please post the logs during playback.  Your friend can check what's happening themselves by bringing up the OSD and selecting Stats for Nerds under the cog wheel icon.  Then have them give you the time and you can grab the appropriate log(s).  If transcoding then SFN can also indicate the reason why.  However, if it's direct playing and everyone is on fiber you shouldn't have too much of a problem unless maybe a proxy, or something else like that is also causing it to buffer.  From what you said though it seems to only happen when it transcodes unsupported codecs.

 

[yocker 1247]

Theres no problems when direct playing, only when playing those mentioned formats and the server having to transcode them for him. All other formats, even when transcoding them and direct play works fine. Fx. transcoding DTS 5.1 doesn't cause any problems but 7.1 does.

I'm willing to live with it as it's very few files that has the problem and by the sound of it there's very little that can be done about it anyway.

[FrostByte 5392]

That's good, if TrueHD becomes an issue it may be a lot more work if your files don't already have an alternate track   

Oh, another thing you can check.  Make sure your friend is running the current version of the app.  You can search for the word "Samsung" in the logs where they played something and somewhere on that line should be the app version.