Absolutely this! There is too much misinformation and confusion in this thread now. The root issue of the whole thread is that: Plex audio content is broken for 4K content (nothing else). The audio offset setting does not resolve this root issue at all - because the offset needed to fix 4K content then breaks all the non-4K content. Face Palm! This same issue is not in Infuse and 4K content works perfectly. (Assuming of course you don’t have general sync issues in your setup anyway - which is a completely different topic).
Haven’t tried Plex for a 6+ months, but tried last weekend and it is as broken as ever, even with the new audio engine. 4K content is miles out of sync and non-4K is very slightly out of sync for me (which got broke after the TVOS16 bugs). With Infuse all my content is perfectly in-sync - no audio offsets required.
And nobody is saying Infuse is perfect! But at least covers the basics!
I am just a Ninja beta tester and another paying user. My statements are not Plex official.
My Technical Perspective Summary
The Plex clients for Apple macOS, iOS, iPadOS and tvOS employ either:
Apple’s Native Player Engine - AVPlayer
Open Source Player Engine - mpv
The former is referenced as the old player. The latter is the new player.
OpenGL has been deprecated by Apple. In order to maximize full hardware acceleration, a player engine needs to support Metal API. mpv does not support Metal API.
On the AppleTV, the old player is not enabled by default–thus the Plex client uses mpv as the engine for playback. It has to use a shim (translation layer) which is part of the reason video is lagging behind the audio. There is no avoiding this penalty. This is happening whether directly connected to a display and using internal speakers or outputting to AVR/soundbar.
For reference, Infuse uses a custom player engine built from the ground up to leverage Metal API.
Long term fix for this can only be resolved in three ways:
Apple develops AVPlayer to support more container formats, more video codecs and more audio codecs. ‘mpv’ supports much more than AVPlayer does
‘mpv’ developers add support for Metal API. Not likely anytime soon as this was a known issue already in late 2017 by then lead ‘mpv’ developer wm4
Plex builds their own player engine or shifts to something like libVLCcore (devs for Swiftfin to connect to Jellyfin are already leveraging this engine)
There is no easy solution to resolve this as the core issue is with the deficiency of the player engine. If you must use an AppleTV, enabling “Use old player” is the only limited but functional way to use Plex on AppleTV. I personally use the Shield as I spent a lot of personal time with the Plex and Nvidia staff to vet out a ton of deficiencies in resolution switching, refresh rate switching and proper handling of all the mainstream codecs.
Thank you for the insight! Makes perfect sense and would be totally explain why Plex haven’t fixed the issue. Shame Plex can’t just be honest and confirm this officially - we would all then just move on and not waste any more time here.
I used to use a Shield before getting the ATV, but I had issues with it and I didn’t like the advert infested UI you get with Android TV. Mine would sometimes not turn on without pulling the power cable out to reset it. Sigh - will there every be the perfect solution?!? lol.
One point/question (just out of interest): I don’t see any audio sync issues on iPad Pro or iPhone and they are both using the “mpv” player. Is there a reason the issue only shows on the Apple TV?
To be honest, I’m a bit skeptical, because you’re proposing an explanation, but there is no data that would back this explanation.
The fact that the OpenGL has been deprecated does not automatically mean, that its performance is not sufficient to render 25 two-dimensional frames per second.
How did you come to this conclusion? Are there any measurements? What is the other part of the reason that leads to the lag?
Because I helped the dev (no longer with Plex) test it when it was created. Performance was already an issue from the onset. tvOS16 API changes further compounded the issue.
Plex is “laying off” staff because their new ad-ridden nonsense is not performing as well as they hoped because the core user base does not want it.
It’d be nice if they could wake up, realize what Plex is, who it’s for, and what made it successful in the first place and focus on that. That work starts with making what is assuredly one of the most popular clients work properly with basic playback. Otherwise Plex can and will go the way of AOL, Yahoo, and many others.
