I am experiencing lip sync issues where the audio is behind the video by 70-120 ms (depending on a few variables). I can replicate this using a Vero 4K+ and a RPI4, both on 2023.01. I can work around this by deactivating video hardware acceleration, which allows audio to gain up to 150 ms relative to video (so that audio is now always ahead of video). The workaround is not usable as most videos in my collection can’t reliably play without hardware acceleration.
For some time I suspected I was seeing a lip sync issue, but I never bothered investigating it until I got a new TV + soundbar combo. I assume this new combo pushed the audio delay beyond a reasonable threshold which started bothering me, so I started a long process to investigate (and learn about) audio-video sync issues. I can’t yet indicate which OSMC version this delay was introduced in, but it it’s happening on the current version.
I tested this with Vero 4K+ and RPI4, using 2 differnet TVs (TV1: Samsung Q90R, TV2: Samsung QN95B + Samsung Q800B soundbar). TV1 does not have a soundbar. TV2 has a soundbar, but was also tested with TV speakers only with a similar result. Contrary to my initial suspicions, I have confirmed the TVs are not introducing the audio delay. Since I’m observing this on both Vero 4K+ and RPI4 I guess the issue is not platform specific.
I’d like to know if this is a known issue with Kodi or OSMC, and what kind of troubleshooting steps or logs are required.
Sanitized logs while playing a test file on Vero 4K+ while connected to TV2 & soundbar (Vero 4K+ → TV → soundbar): https://paste.osmc.tv/birodilase
Past threads from 2019 on this topic:
Audio-video delay testing:
- Test files: 1920 x 1080 Files - Sync-One2
- AV Sync test app: https://play.google.com/store/apps/details?id=com.stevedenheyer.avsync
- I have used both a MacOS and a Linux device as a reference for the zero delay / in-sync state. I then used that reference to obtain a fairly reliable A-V sync delay offset for each of the 3 Android devices I tested with. This was needed because each of the 3 Android devices had different reading of the same reference delay.
- In previous iterations of my tests, I was recording the TV while displaying various test A-V sync videos, then playing back at reduced speed to more easily read the delay. I have found the app approach to be a lot more reliable, but the results were consistent.