Audio and video not aligned since updating to latest version

[Dog_Bronson 2]

Hi

As the title states, the audio and video are not aligned after updating the LG Emby app to the latest version. The audio is consistently just a tiny bit ahead. Not enough to make it unwatchable, but definitely noticeable and annoying. Sometimes stopping playback and resuming will fix it, but usually not. Sometimes it starts out fine, but gets more and more unaligned as time goes on. This problem wasn't present before updating.

embyserver.txt

[Luke 42077]

Hi, what were you playing?

[Dog_Bronson 2]

If you mean info such as filetype and other data, just some pretty standard .mp4 files with the occasional .mkv. Stuff mostly like this:

Title1080p HEVC

CodecHEVC

Codec Taghev1

ProfileMain 10

Level120

Resolution1920x812

Aspect Ratio480:203

InterlacedNo

Framerate23.976

Bitrate2 mbps

Bit Depth10 bit

Pixel Formatyuv420p10le

Reference Frames1

[Luke 42077]

What is the audio?

[Dog_Bronson 2]

Oops, sorry. Meant to post that too. Typically something like this:

TitleEnglish AAC 5.1 (Default)

LanguageEnglish

CodecAAC

Codec Tagmp4a

ProfileLC

Layout5.1

Channels6 ch

Bitrate224 kbps

Sample Rate48,000 Hz

DefaultYes

I also forgot to mention that I updated the TV at the same time. Could be just an LG issue.

[Dog_Bronson 2]

Any update on this?

[Luke 42077]

Hi, we are looking into it, but as it is direct playing I am not really sure that it is associated with the update. We are just feeding the original file to the LG video player. I know there have been numerous LG software updates recently so that could be part of it. It's possible that the previous app version was having the server transcode this video, but based on media info you provided I would say that's unlikely.

[Dog_Bronson 2]

Thanks. I figured it's probably just an issue with the LG software itself. There was another update recently, and I delayed downloading it to prevent running into further issues. But I did download it yesterday. Since then it seems like this issue has gone away.

[Dog_Bronson 2]

Guess I spoke too soon. For some files, it's aligned perfectly. For other things I watch, it's worse than ever and renders Emby practically useless on my TV. There seems to be no rhyme or reason to it I can discern, except that when audio is heard earlier than video, it's always an .mp4 - but not all .mp4 files have this problem.

[Luke 42077]

hi, we'll have to see if we can detect it and have the app automatically switch to server transcoding. That should clear it up.

For now you can do this manually by selecting playback correction in the video player.

[Dog_Bronson 2]

Thanks. Selecting Playback Correction doesn't seem to  seem to work. I think the problem might be since I'm only using TV speakers that when a file has 6 channel audio, the audio track getting downmixed is causing a desync. Every file that I play that has the issue has 6 channel audio.

Just a thought to help point in a direction.

[Luke 42077]

3 hours ago, Dog_Bronson said:

Thanks. Selecting Playback Correction doesn't seem to  seem to work. I think the problem might be since I'm only using TV speakers that when a file has 6 channel audio, the audio track getting downmixed is causing a desync. Every file that I play that has the issue has 6 channel audio.

Just a thought to help point in a direction.

What makes you think selecting playback correction doesn't seem to work?

[Dog_Bronson 2]

Because when I did it the audio was still not aligned with the video, same as before. I should have been more specific, sorry. It "works" in that the prompt comes up on screen and details what it does and that it might fix issues, but it did not fix my issue in particular.

I ran a script to downmix a file with 6 channel audio into 2 channel stereo. Audio quality took a small hit, but I think it confirmed the problem. With 2 channels the audio is no longer out of sync with the video. I then went through and looked for any files that already had 2 channel audio, and they play fine. It's definitely every file that is surround sound being downmixed that causes the delay.

[Luke 42077]

1 minute ago, Dog_Bronson said:

Because when I did it the audio was still not aligned with the video, same as before. I should have been more specific, sorry. It "works" in that the prompt comes up on screen and details what it does and that it might fix issues, but it did not fix my issue in particular.

I ran a script to downmix a file with 6 channel audio into 2 channel stereo. Audio quality took a small hit, but I think it confirmed the problem. With 2 channels the audio is no longer out of sync with the video. I then went through and looked for any files that already had 2 channel audio, and they play fine. It's definitely every file that is surround sound being downmixed that causes the delay.

But in the log example you provided, Emby was direct playing the original file. There was no downmixing occurring, at least not by Emby Server. The TV might have been doing that.

Or is that not the right example?

[Dog_Bronson 2]

I guess it's the TV then, because all I have are TV speakers, no surround sound setup. If Emby isn't downmixing it, then it only makes sense that the TV is doing it.

The log is outdated, but I've since converted the audio from those files from 6 channels to 2, and they play perfectly now. Sorry, I don't understand this stuff very well. All I know is that when I convert the audio to 2 channels, the audio and video align correctly.