Lip sync issues (audio is delayed)

[valentin_osmc.tv_gef]

Thank you all for the replies.

@MidnightWatcher

Is this for all videos? If yes, play a video, go to the audio settings, adjust the Audio Offset until it’s in sync and then Set As Default For All Media.

Thanks for the suggestion, unfortunately it’s not as easy as that because the audio delay changes with the various formats. There isn’t a single offset I can use that will work for every case. I have tried compensating with a file-specific delay, but it is not something I look forward to doing on a continued basis.

@sam_nazarko

Please change Adjust Refresh Rate to Always.

It is already set to “On start / stop”, including during the test. Is there any practical difference between that and “Always” when it comes to the audio delay issue?

@sam_nazarko

I note your soundbar supports AC3, but not DTS passthrough.
AAC, in your sync test video, obviously cannot be passed through.

The soundbar I think is a red herring, as is the passthrough option. I can observe the same audio delay with the soundbar disabled (TV2) and with no soundbar (TV1). I can also observe the same audio delay with passthrough enabled / disabled, so I believe it is not a factor.

AAC was the format in the test file I submitted logs for, the other format I tested with is PCM. I am trying to keep number of variables to a minimum to make it easy for anyone else to try to replicate.

@sam_nazarko

Do you experience issues when playing AC3 content?
Do you experience issues when playing content with DTS soundtracks?

It’s difficult to judge when watching content, hence why I tried to use the testing methodology described. As stated in the OP, I subjectively felt something was off for some time, but due to life and priorities I never bothered investigating. Now I made the time and can put into numbers what I subjectively felt was off.

If you can provide a similar sample file with AC3/DTS I would be happy to test. For most of my collection I believe AC3/DTS is not relevant, as I’ve been happily watching the content on TV speakers for a long time.

@sam_nazarko

Given the limitations of your system (Samsung – so no DTS license); I’d be inclined to disable passthrough; use LPCM and configure a global audio offset.

Thanks for the suggestion. That does sound like a work-around, but as stated earlier I’d like to investigate the root cause and possibly find if it is fixable.

Offtopic: I was aware Samsung TVs do not decode DTS, but they do have the option to passthrough the bit stream to the soundbar, which I believe supports DTS. I have not tested this theory though.

---

To make the problem statement clearer, I’d like to emphasize:

• The problem happens with/without a soundbar
• The problem happens with/without audio passthrough enabled in Kodi
• The problem does NOT happen with 2 other HDMI sources connected on via the same HDMI port & cable, using the same exact settings on the TV
• The problem does NOT happen with video hardware acceleration disabled on Vero 4K+.

---

Even though I appreciate the suggestion for the audio offset workaround, I have not yet given up on finding more understanding of the problem and possibly a fix. To help eliminate any errors in procedure or assumptions on my side, it would be great if anyone else can re-run the same tests and measure the results with the same methodology.

Given all the video processing TVs nowadays do, I’d expect the video to be delayed, not the other way around. So it is surprising to find audio is delayed.

---

Note: I plan to roll back to 2022.03 within the next couple of weeks due to the CEC issue described in 4k+ CEC EARC issue and HDMI-CEC seems to stop working after a couple of hours. I’d appreciate any feedback or test ideas soon so I can run them on the current version.