Interestingly I also had this issue with The Abyss, the first movie I’ve watched all the way through on my AM6B plus. Glad it might just be this particular movie.
This is an issue with Kodi and not CoreELEC and Dolby Atmos issues should be fixed in V22.
interesting read in the github post. So does this mean it’s a coincidence that The Abyss is a seamless branching title, and the core issue is that there are sections of hard-to-compress audio that are catching Kodi out when using passthrough audio?
The fix for this just got merged into the latest Kodi nightly. @Portisch or @vpeter might know when it will be merged. Then, can you retest?
Oh man I really hope that upstream patch finally fixes the Atmos True HD dropouts once and for all. Seems to occur mainly with remuxes made from discs with “seamless” (and I put that in quotes facetiously) branching. Abyss is one. Aliens, Black Hawk Down (probably the worst I’ve encountered so far). So like titles with extended/directors editions with multiple cuts on the same disc, and split up into many pieces. Several Disney titles also have this issue, despite not having multiple cuts ( however these often have nuanced very short segments spliced in depending on whether US, Canada, Mexico for a NA example. Indeed setting decoding to output in LPCM eliminates the issue, but also drops the Atmos.
My Panasonic 820 ironically even still has this issue. So it’d be amusing if the fix works, that Kodi will actually be able to play it better than the legit disc player!
Best I can tell it’s these two commits, that have merged:
This fix should be in the 5/22 nightly!
Early days, but the 5/22 nightly just breezed through the scene in The Abyss where I experience the first dropout with the K21 production release when using Atmos passthrough to my Marantz AVR (around 4:50 as the submarine floods). I now have one AM6B+ on K21 production and another on the nightly. I put the K21 back in and sure enough, there was a dropout in the flooding sequence. Put the nightly back in, no dropout. Might be a while before I have the time to what the entire extended version of The Abyss to see if the dropouts are completely cured, but very encouraging so far.
Big thanks to whoever figured out the code change.
EDIT: seeing some lip-sync issues, will monitor.
I may have spoken too soon. Black Hawk Down played fine at first. However Cars (2006) still had drop outs. Additionally I concur there’s more lip sync issues going on even with Black Hawk Down.
I have only had time to do a brief look. One of the scenes I remember having audio drop out on in The Abyss seemed to play just fine, though I’m not sure how scientific that is as even when it did drop out if I just skipped back a bit it would generally play, so I can’t say for certain it just didn’t happen this time, but might happen again on another play through.
I haven’t had a chance to play long enough to notice any lip-sync issues. Out of curiosity, are you two seeing this issue (lip-sync issues) on everything, or just the “problem” movies you have previously had the audio drop-out issues with?
Also, just to add for datapoints, my Am6b+, running the 5/22 nightly, is connected to a Marantz SR6015 receiver, which is connected to an LG C1 (55"). Playing Atmos in passthrough. The copy of The Abyss was the Special Edition as ripped from the disc by me, using MakeMKV, and then converted to P8, since its an MEL title (I still do this for MEL movies for greater compatibility with other devices I might use, like my AppleTV running Infuse).
Just the problematic Atmos movies with previously experienced audio dropouts. Seems to trigger between the a/v corrections incidents. Like it would sometimes go out of sync on one event, only to come back into sync on a subsequent event.
I doubt the receiver or audio gear would matter. All three of my TV setups do this (one LG TV with Emotiva receiver, another Sony TV with Nakamichi soundbar, another Sony TV directly connected with a subsequent spdif connected legacy soundbar).
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I just noticed terrible lip-sync on Strange New Worlds UHD (DTS-HD audio), so wonder if the 5/22 nightly has more general lip-sync issues. (passthrough to a Marantz AVR).
so I’m on 05/27 nightly now, trying The Abyss again, lip sync starts off fine with Atmos passthrough, but can be broken completely by a chapter skip, with audio nowhere near in time with the picture. Source is mkv direct from disc via makemkv, and the lip sync issues are present across HDR10, player-led and TV-led DV. But last night I watched Transformers (2007) UHD, and tha Atmos lip sync was perfect throughout, so this isn’t an issue with all Atmos titles.
I just tried The Abyss (just jumping around and such) on the latest Nightly (5/29) and saw no lip sync issues, even when skipping chapters. Admittedly I just watched briefly and here and there.
is anyone here has green screen weird color on HDR10+ videos ?
Weird green screen will appear if I played HDR10+ video after the devices powered on / after reboot.
to fix the issue I have to stop the video and press play again then green screen just disappear by itself … 
but after reboot device green screen comeback again.
Ugoos am6b+ / Nightly 20240529 / LG C1
Example:
Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main 10@L5@Main
HDR format : SMPTE ST 2094 App 4, Version 1, HDR10+ Profile B compatible
Codec ID : V_MPEGH/ISO/HEVC
Duration : 1 h 32 min
Bit rate : 19.1 Mb/s
Width : 3 840 pixels
Height : 1 920 pixels
Display aspect ratio : 2.000
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 10 bits
Bits/(Pixel*Frame) : 0.108
Stream size : 12.4 GiB (97%)
Default : Yes
Forced : No
Color range : Limited
Color primaries : BT.2020
Transfer characteristics : PQ
Matrix coefficients : BT.2020 non-constant
Mastering display color pri : Display P3
Mastering display luminance : min: 0.0001 cd/m2, max: 1000 cd/m2
Maximum Content Light Level : 829 cd/m2
Maximum Frame-Average Light : 419 cd/m2
Yes same problem with HDR10+ green screen (mainly those vids that came from Amaz Prime). Looks like the same MediaInfo on my vids as well. Have to stop/restart
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Why would you even watch HDR10+ on your C1? Its not supported by your TV… I have a LG G1 so I know what I’m talking about 
Because I have many HDR10+ video files and lately AMZN came with HDR10+… and even i played it on Ugoos am6b+ with LG C1. It should be played/fallback as HDR10 right ?
It is working fine but the ploblem is I have to stop and start video to avoid green screen color.
Also seen some issues with AMLogic / SoC not working well when there is HDR10+ side data in the video stream on non-HDR10+ displays.
Likely solution is to remove the side data (via quietvoid’s lib - already used for dv) if the display is not HDR10+ capable, resulting in just basic HDR10, rather than relying on AMLogic to do it correctly.
If you want to test if that is going to work for your files I already do this in my DV test builds when VS10 mapping, so could up map HDR10+ to DV and see if all good - highly recommended to try that on a separate micro sd-card, not your main install.
Yup latest nightly CoreELEC-Amlogic-ng.arm-21.0-Omega_nightly_20240424-Generic.img still having the green screen with that media type.
CoreELEC Team: Is this something that is fixable? Cheers
reversed thanks for no help
I definitely see this as well. Stop and play the video again fixes it every time, which makes me think this is a coreelec/kodi issue rather than a AMLogic SoC thing, but who knows.