Fixing seamless branching audio dropout and sync issues on exoplayer

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tresnugget
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by tresnugget »

I read about dgdemux after running into the infamous audio drop then sync error on exoplayer with extended cuts and seamless branching on rips being played on Plex+shield with a few UHD titles. I'm trying to get F9 to work and to be honest I'm pretty green when it comes to all of this. So far I've demuxed from a disc backup, remuxed with mkvtoolnix into mkv. I've tried both the combined thd audio and separated thd with the same results each time. Also tried the chop excess audio option, with both separated and combined thd and same luck. Anything I'm doing wrong or can try? Thanks
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Rocky
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by Rocky »

Welcome to the forum!
I've tried both the combined thd audio and separated thd with the same results each time
Please tell us what the results are and what problem you run into. Also tell what F9 means.
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tresnugget
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by tresnugget »

Rocky wrote:
Sun Jun 04, 2023 5:03 am
Welcome to the forum!
I've tried both the combined thd audio and separated thd with the same results each time
Please tell us what the results are and what problem you run into. Also tell what F9 means.
Thanks! And sorry, I could have been more descriptive.

So as a background, Plex and Jellyfin running on the Nvidia Shield Pro use Exoplayer which has issues with TrueHD/Atmos tracks from seamless branching rips. The UHD extended versions of Black Hawk Down, The Martian, M3gan, and F9 (Fast and the Furious 9) are notable offenders where once you get to a branch/added scene the audio drops for half a second and from there the audio is out of sync. If you jump back or forward then the issue corrects itself but with some some of these this can happen every 10-20 minutes.

With Jellyfin you can switch the player to libvlc and the issue goes away but you lose Dolby Vision and honestly I'm not the biggest fan of Jellyfin, but the point being that it's definitely an issue with Exoplayer, however I've seen some report that with certain players (can't remember which), during the branch points, they've gotten messages that the stream was no longer lossless.

This has been an issue for years and the devs behind exoplayer blame "malformed mkvs" for the issue although after a lot of community backlash they have reopened the ticket so who knows? In the exoplayer GitHub community page and makemkv forums I've seen people recommend dgdemuxer but with F9 (I haven't tried any of the others I've mentioned) I've had 0 luck, and the result has been the same as when ripping the disc with makemkv, and other tools. Have any suggestions?
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Rocky
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by Rocky »

Thank you for the information. Please answer this as fully as possible:

After you demuxed with DGDemux (latest version 1.0.0.69) from the disc and then remuxed to MKV, what is the problem you have playing the MKV? Does it show the same problem playing in software media players like MPC-HC, VLC, etc.?

If you can show a problem with the remuxed MKV when playing in a media player, then I'll be able to investigate that. But if it works fine with media players but not in your Shield stuff, then you'll need to get support from those guys. I don't know a single thing about Shield, Jellyfish, or any of that stuff, nor do I own the requisite hardware.

DGDemux makes a clean single-file rip, correcting for the M2TS gaps. There should be no problem playing it after remuxing to MKV. I've done it many times. There simply are no gaps remaining after this process.

Did the exo guys explain what they mean by 'malformed MKV'? Cop-out?

Links to the discussions you mentioned would be helpful too.
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tresnugget
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by tresnugget »

Rocky wrote:
Sun Jun 04, 2023 9:41 am
Thank you for the information. Please answer this as fully as possible:

After you demuxed with DGDemux (latest version 1.0.0.69) from the disc and then remuxed to MKV, what is the problem you have playing the MKV? Does it show the same problem playing in software media players like MPC-HC, VLC, etc.?

If you can show a problem with the remuxed MKV when playing in a media player, then I'll be able to investigate that. But if it works fine with media players but not in your Shield stuff, then you'll need to get support from those guys. I don't know a single thing about Shield, Jellyfish, or any of that stuff, nor do I own the requisite hardware.

DGDemux makes a clean single-file rip, correcting for the M2TS gaps. There should be no problem playing it after remuxing to MKV. I've done it many times. There simply are no gaps remaining after this process.

Did the exo guys explain what they mean by 'malformed MKV'? Cop-out?

Links to the discussions you mentioned would be helpful too.
With Exoplayer/Plex/Jellyfin on Shield the audio cuts out and comes back and from there it's out of sync. It can resync with a forward or backward bump but the next time it hits a branch it happens again. It's only extended versions. The theatrical cuts all work.

With MPC-HC there's a very very quiet mild pop at the point it normally desyncs but other than that it plays perfectly. Other than Exoplayer the only other player that I've seen that had this issue was Kodi but it was fixed.

But no, they didn't explain anything. They quote a Dolby support page that states TrueHD/Atmos isn't supported in mkv containers and that they wouldn't be putting any more time into it and closed the ticket. That was 3 weeks ago and it looks like it has since been reopened but they haven't made any statements so maybe they'll get it fixed. But yeah, total cop out.
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Rocky
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by Rocky »

Thank you. Based on your information I cannot think of anything we can do to help with this issue. If Kodi, etc., have been able to fix it, then exoplayer should be able to do it too.
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Hurin
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by Hurin »

Hello Rocky!

I wonder, given your expertise, if you wouldn't mind posting a bit more detail that might help us convince the Google Exoplayer team to take this seriously and stop passing the buck/blame-shifting.

If you're curious, here's the thread where exoplayer has posted their various excuses. They have basically putting us in a position of trying to prove a negative. We basically have to prove that there is nothing wrong with the way these MKVs are being created before they'll even begin to consider the issue.

I plan to already use. . .
DGDemux makes a clean single-file rip, correcting for the M2TS gaps. There should be no problem playing it after remuxing to MKV. I've done it many times. There simply are no gaps remaining after this process.
. . . but I was wondering if you have any more to add?

Thanks for anything you can provide! I know this isn't your fight. But we're desperate as a community and begging anyone who can to help!

Best Regards,

Hurin
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Sherman
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by Sherman »

Yeah. Going to go read that now. Thanks and welcome to the forum!
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Hurin
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by Hurin »

Thank you so much! As mere laypeople and end-users who neither code nor understand the intricacies of the technology, we are at a distinct disadvantage while discussing such things with the exoplayer team. So, while (again) this is not "your fight". . . any expertise or advice you can share would be immensely appreciated. Even if it actually proves us wrong and supports the exoplayer team's take on the matter.

One post over there that should be emphasized, I suppose: Exoplayer Team's final (so far) word on the matter is here. Where they simultaneously stand on the princple that they aren't going to change their application to fix something that isn't demonstrably their responsibility while also stating that they'd accept a "high quality" patch from the community.

I mean, I concede that it's conceivable/possible that the exoplayer team is correct that there is something wrong with these streams and that it's not technically their problem. . . but that seems less and less likely the more we understand about the nature of the issue and how so many players (both software and hardware) have seen similar (perhaps identical) issues in the past and addressed them at the player (not media) level.

Anyways, I ramble on. This has become a bit of a "white whale" for me. Any and all assistance/information/advice is appreciated!

--H
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Sherman
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by Sherman »

Finally, someone on the ball. What a pant-load from those guys. It's a moral imperative to try to help someone, even if they are stupid? How much time and effort? I don't know, what do you think, Hurin?

Wanna see my new solid rocket motor design? It incorporates elements of drone technology and advanced tensor analysis for navigation and control. Flight time and payload are currently limited. What are your GPS coords again? Even a cherry bomb can spoil your day.
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Wonder Woman
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by Wonder Woman »

Pay attention. OP said patches welcome. So is the source code available for this thing? :?: :?: :?:

I'm strong and independent so I might as well be smarter too.
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Hurin
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by Hurin »

I'm no software developer, but it appears source is available here: https://github.com/google/ExoPlayer
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Hurin
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Fixing seamless branching audio dropout and sync issues on exoplayer

Post by Hurin »

Sherman wrote:
Tue Jun 20, 2023 4:28 pm
Finally, someone on the ball. What a pant-load from those guys. It's a moral imperative to try to help someone, even if they are stupid? How much time and effort? I don't know, what do you think, Hurin?
I'm not really qualified to judge. I'm just a layperson with a piece of hardware (NVIDIA Shield) and software (exoplayer via Plex) that isn't working. And hoping someone with expertise in the area can clarify what's truly going on so that we can begin moving towards a solution.

I'd abandon the NVIDIA Shield as an option if I could. But since it runs the only Plex client that will do HDMI passthrough of uncompressed audio, that's not really an option.
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