[RedTwenty50]

Thanks Kodi team for your amazing work and apologies for bringing another TrueHD issue. I will try to make this clear and to the point.

Kodi Versions tested and affected:
20.5
21 Beta 2
21 RC1

Platforms tested:
Android / Windows

Affected Source files (read via Gigabit connected SMB share):
Cars (2006)
Cars 2 (2011)

Issue:
When using the TrueHD Atmos tracks in passthrough, I get audio drop outs and cut outs. The issue seems to occur only for seamless branched sources around seamless branching points, and usually around the same parts. However while it occurs more times then not, it does not always occur at a given part, nor does it occur at the same exact points most times.

Troubleshooting performed:

• Recreate the file with the latest version of MakeMKV and DGDemux: Did not fix
  
• Try it in VLC (Android/Windows): No issues found
  
• Try it on Windows Kodi: Did not fix
  
• Try it on another AVR / Soundbar that supports TrueHD passthrough (Android platform): Did not fix on the two other systems tried
  

Debug log from Android on Kodi 20.5:
atanowavek.kodi (paste)

Some rough timestamps I took to hopefully help sift through the log:
16:08:52 - Dropout but comes back
16:13:20 - Dropout but comes back
16:23:01 - Cutout, rewind did not fix, stopped and restarted
16:25:58 - Cutout, rewind did not fix, stopped and restarted
16:32:40 - Dropout but comes back
16:38:50 - Cutout, rewind did not fix, stopped and restarted

Side note / observation:

1. When looking at logs myself (not for every test), I did find that when the issue took longer to occur / between occurrences, the self-learning fix that was implemented had set a longer delay.
   
2. One of my AVRs (ONYKO RZ50) eventually ends up dropping out and coming back with a glitchy sound (I assume in response to the dropouts, but not a Kodi fault). While it does not fix itself without reloading the file normally, when using the advancedsettings.xml setting 'maxpassthroughoffsyncduration' it then will fix itself. My understanding is this is an Android only fix, yet this problem also occurred using Windows on said AVR, so it seems the maxpassthroughoffsyncduration shouldn't be the culprit.
   

Thanks in Advance, if there is anything else to try or you need more logs, let me know so I can assist where possible.

[RedTwenty50]

Quick update, tested with Kodi 21 RC2 and Cars (2006) still has the same issues. I have also tried some other TrueHD titles and these are the results:

Enchanted (2007) - No issues the whole way through (this was on RC 1 however)
Fast and Furious 9 (2021) - No issues within 30 minutes (issue usually occurs by then if there is one)
Midway (2019) - No issues within 30 minutes (issue usually occurs by then if there is one)
Elemental (2023) - Two drops and then eventually changed to glitchy sound with the RZ50 for a second or two before correcting, all within the first 7 minutes
Aliens (1986) - No issues within 30 minutes (issue usually occurs by then if there is one)
The Suicide Squad (2021) - Two drops within 30 minutes

Cars (2006) and Cars 2 (2011) were much like Elemental (2023) in that they drop out many times within a short timeframe / more frequent dropouts

[RedTwenty50]

Cars 3 (2017) with Kodi 21 RC2 also has issues within the first 14 minutes

[RedTwenty50]

Is there anything else I can try or information I can give that may help?

[mikeSiLVO]

Hello and sorry that I cannot be of any help with this issue as it is way beyond my knowledge but I noticed you have provided a decent amount of detailed information including an actual debug log.

If possible can you post this as an issue on GitHub?

If you can provide a debug log with both Android and Windows, they could be most informative.

No guarantees but it may be seen by a developer if they have time to look into it.

Thanks

[CrystalP]

The problem will likely be the reproduction of the issue, you should cut a small sample from the original file around a time where the problem happens.
Or point to existing public samples that exhibit the issue.

[crawfish]

If it's anything like the bug that affected Sony Bluray players, a workaround may be to switch Kodi to 2ch output. Not what you want to hear, but it may make the movies watchable until you get a fix. For many discussions about the issue, google /bdp-s1500 seamless branching audio dropouts/. Besides the ancient history, the search also turned up this bug report for Nvidia Shield ExoPlayer on Plex and JellyFin from August 2022:

https://github.com/google/ExoPlayer/issues/10520

I see the OP linked to a sample that reproduces the problem on that platform.

[RedTwenty50]

Thanks everyone for your responses and possible things to try, I have been undertaking those things and these are my findings below (again used Kodi 20.5 as the latest stable version):

1. Upon making the Android and Windows logs, I found that while the RZ50 had the glitch noise issue occur and then self-recover when using Android, the Windows test had an early drop before later having the glitch noise issue occur where the Android one had recovered from
   
2. Duration does seem to play a factor to when you will get a dropout / consistency of dropouts, as when I play the first 5 minutes fully, I will pretty consistently get the dropouts or glitch issue, however when I trimmed the file down to only the selected minute that has the issue, or used the linked to sample crawfish found, I only get one drop in that time, which for crawfish's found sample did happen where it was said to happen, but only occurred 1 of 3 times I tried, so it's seemingly less consistent.
   

These are my new logs that I have made and I will be posting the issue on Github soon:
Shorter Android Log - Glitch Sound Drop but then recovered (around 4-5 minutes in the 'test.mkv' file): lepusidepa.kodi (paste)
Windows Log - An Early dropout and then later glitch Sound occurs where the Android one recovered (again around 4-5 minutes in): opowiniriq.kodi (paste)
Windows Log - Tried to trim it to the minute, but only got a dropout: qivaxigaca.kodi (paste)

[RedTwenty50]

Thanks crawfish as well for the potential workaround and your help, thankfully for anyone suffering this issue, you doesn't have to go as far as to lose 7.1, but you may lose the Atmos/Vision features with the workarounds I have found.

If you get Kodi to decode the audio (disable passthrough), you will have no issues and 7.1 output, and Dolby Vision if you're using Kodi 21. If you use VLC to passthrough, you will keep Atmos but lose Dolby Vision. I used the Kodi decode method after the 14 minutes on Cars 3 (2017) and that worked well.

[RedTwenty50]

Github Issue Posted here: 24944 (GH issue)

Sample file here: https://drive.google.com/file/d/1zkcp5aO...vDuVM/view

Watch and wait to hear the audio dropouts occur, in the case of the sample file, it can come up when it mentions 'Pixar' with the cars going around, or when they mention 'the last thing they expect was lightning mcqueen' or a little after 'three cars, one champion'

[RedTwenty50]

Noticed we have a new stable Kodi 21, sadly that is also affected

[Hitcher]

Odd, I played your sample perfectly on my Shield TV Pro.

[RedTwenty50]

Odd, I played your sample perfectly on my Shield TV Pro.

That's good then if so, I find it is a quick (around 1 second) dropout on most of my devices, do ensure you have TrueHD passthrough enabled as Kodi can decode the audio just fine when not in passthrough as welll

[Hitcher]

Yep, my Denon X2500H is displaying Atmos-DTHD.

Make sure you have 'Match content audio resolution' disable is the Shield TV advanced sound settings.

[RedTwenty50]

Yep, my Denon X2500H is displaying Atmos-DTHD.

Make sure you have 'Match content audio resolution' disable is the Shield TV advanced sound settings.

Very well, hopefully Denon's are unaffected. It seems different AVRs handle these codecs differently and can have strange problems, my other AVR does this weird beep/static with Disney Atmos tracks at fixed points for example (it's the AVR as it doesn't matter what is playing it). In saying that once or twice I did manage (out of the many) to not have any issues within the first 14 minutes, thankfully for testing most of the time it's within less than 5 minutes.

I thought I had that turned off due to it being mentioned in previous threads, however seems I didn't, tried again after making sure it (and dolby processing) were off, but still had the glitch and got a drop out using Github-thexai's test build, their build does seem to make these dropouts a lot rarer though.

thexai notes the file has a lot of padding, but having tried to do it fresh with two updated tools to try to clear that as a cause, I am not sure what other tools to try