ATMOS Audio Drop Outs - Details thread


I guess there are a couple of options for now to “avoid” the broken TrueHD/Atoms track, and all will give “Lossless” sound but not ATMOS:

  1. Decode instead of Bitstream - This works, and I could make a “Zone Switch” in JRiver with a feild like “Bitstream” = No for these titles and then it would switch to decoding. Benefit is when/if it is fixed I can just remove this value for these titles.
  2. Mux In DTS-MA Track - Got this idea from @gonca but instead of re-encoding, I’ve muxed in the DTS-MA track (using tsmuxer) the DTS-MA track from the BD disc that came in the same packaging (tsmuxer has not been updated for some time but seems to work fine). I then replaced the M2TS in my older structure and it worked fine though some of the PGS tracks now don’t have a lang tag. These DTS-MA tracks are reported as being slightly different in length but it must be at the end as the lip-sync is spot on for both Pirates and GG2. I guess you could do the same with the MKV muxers.


Re: Zone Switch - I may do the opposite rule. If Bitstreaming = “Yes” for discs with ATMOS or DTS:X. That way I can use MC’s Audio Processing with all other discs in my collection (eg Videosync).


the muxing of the dts tacks is a great idea. i really need to start playing around with jriver tagging and rules more. currently i use one rule which changes the channel output for 4.0 dsf files as jriver seems to want to play them back as 2.0 unless i set the layout to 5.1.

i am almost done re-ripping all of my discs that can be. i would estimate at least 50% re-downloaded data from arusoft. i suppose that is good as it means they updated their database. wish they would add a feature that indicated this to the user as it seems their method is not perfect and is updated on a title basis.

as i have several titles with both 4k and 3d versions have you tried or is it possible to add two video streams into one mkv and select which to playback?


Lots you can do in MC. If you want 2 versions to show up in MC from the one file (eg 4K and 3D, or Theatrical and Alt Ending, or ATMOS vs DTS-HD etc), then you create a “Particle” and then select the streams you want (during playback - which will then be remembered for next time) . I’m a folder ripper so can’t help much on how to mux into a single MKV, but if they show up as different streams that you can play in MC you are all good to go.


Another post from Nev/Hendrik on ATMOS drop outs:

[QUOTE=nevcairiel;1829767]Atmos bitstreaming is not fully understood. If the bitrate exceeds a certain limit, it breaks apart, because its not known how to handle that. This was never a problem with ordinary TrueHD since the bitrate doesn’t get high enough. Unfortunately the specifications for that are not available anywhere online (not even to buy), since its not part of the IEC standard that usually controls HDMI bitstreaming. So if anyone knows how Dolby MAT (Metadata-enhanced Audio Transport) works - the format used to wrap TrueHD and Atmos for HDMI transmission, please let me know. :)[/QUOTE]


Certainly seems we are not going to get any VUKs for Guardians or Pirates so it might be a while until this mystery is solved.


I doubt it would make a difference anyway (but it would have been good to rule it out). Looks like we are with this issue until ffdshow devs work it out. For these discs I’m going to Decode instead of Bitstream…


@Balthazar2k4 Have you tried this with a MakeMKV rip yet?


Yep. Still there. The problem isn’t the disc or the rip…

Titles Support List

As UHD BD playback is about to get a giant boost, I’m sure that the devs involved with ffmpeg will become keen to look at the issue.


Posted this over in the Kodi forums:


Plex media player on my windows 10 HTPC experiences drop outs in audio too. I think we need to open a ticket with ffmpeg directly. I am going to test using media player classic which I think is also using ffmpeg lib.


Blade Runner 2049 - around the 45min mark theres an audio dropout.


Is it repeatable?


Once we finish I will test again; but the behavior was identical to Pirates, receiver stops playing all audio and displays None for audio before recovering a few sec later. I’m using Plex on my shield with an Anthem MRX1120 receiver in 5.1.4 config.


Again around 1:49.30…sigh.


So my Shield will occasionally have Atmos dropouts on content, but it isn’t repeatable like on Pirates of the Caribbean. Usually if I rewind a tad and replay the moment the dropout occurred the dropout does not repeat. I think in those cases it is some kind of buffering issue. Annoying, but not content related.


interesting. My servers are on 10Gbit so not a network issue, but I am not able to reproduce on my shield again. Must be some sort of shield bug.


Blade Runner 2049 played without drop outs for me (PC using LAV)


My Shield is hardwired too and yet I still get the occasional dropout. It is certainly a Shield bug.