Topic: Atmos Drop Out Thread (when bitstreaming) (Read 3561 times)

jmone · « **on:** April 29, 2018, 07:14:59 am »

Quote from Hendrik on ATMOS drop outs:

Quote

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.

So far the titles impacted are (and they are all Disney Films):
- “Pirates of the Caribbean - Dead Men Tell No Tales” - Max Bit rate is 11.9 Mb/s : eg drops out a couple of times between 17:45 and 19:00 minutes into the movie
- “Guardians of the Galaxy Vol II” - Max Bit rate is 11.3 Mb/s: eg drops out at 1:09:24 where TaserFace gets killed is one example.
- “Maze Runner: The Death Cure” - Max Bit rate is 12.1 Mb/s: eg Right at the beginning of the Main Title when the 20th Century clip is running. Drops outs so frequent that playback for me actually stalls.

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:

Decode instead of Bitstream - This works, and you could make a “Zone Switch” in JRiver with a field like “Bitstream” = No for these titles and then it would switch to decoding. Benefit is when/if it is fixed your can just remove this value for these titles.

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. One downside is if you are using BD Menu Playback then this modified files will not work as it confuses the menu playback (but is fine in Title Mode).

rec head · « **Reply #1 on:** April 29, 2018, 07:36:50 am »

I just checked Guardians v2 because I didn't remember any dropouts but I got it. Didn't seem like a big enough deal to stop bitstreaming the ATMOS track. If they were frequent I would.

jmone · « **Reply #2 on:** April 29, 2018, 07:39:24 am »

It depends on your setup. Some only get a short drop out.... Unfortunately, I get a 10-Second Drop out each time (with my JVC X7500 PJ in the chain). It's a PITA. On my LG OLED it is just a short blip.

TheShoe · « **Reply #3 on:** April 29, 2018, 03:36:57 pm »

Quote from: rec head on April 29, 2018, 07:36:50 am

I just checked Guardians v2 because I didn't remember any dropouts but I got it. Didn't seem like a big enough deal to stop bitstreaming the ATMOS track. If they were frequent I would.

watched about half of GoG last night. first and very brief audio dropout happened for me towards the beginning when they were fleeing the planet after stealing the batteries (sorry. dont recall the time nor know the movie that well)

pirates for me has pretty much exact same drop outs as others have reported, though for me each time it is brief, 1 sec or less

jmone · « **Reply #4 on:** April 29, 2018, 04:54:39 pm »

Tested “Maze Runner: The Death Cure” with another rip to folder (one was MakeMKV, the other AnyDVD). This is an easy one to find an example. There are a series of rapid ATMOS drop outs right in the opening 20th Century Fox logo when playing the main movie. My ATMOS decoder light goes mad on the Yami RX-A3060 flashing on and off and it can be so bad that playback then actually then stalls. Switching to decoding the audio and it plays fine. Discs plays fine on the XBoxOneS on the same AVR/PJ setup.

Edit: Also tested on my LG OLED (feed by another RX-A3060), but this one is a 5.1 setup (no atmos speakers) so I normally decode on this rig. Switching to Bitstreaming to test, this rig (with the LG OLED) is better behaved as the drops out are only about 1 sec (about 4 of them in this opening sequence). At least playback does not stall.

(note: cross posted at MYCE)

Hendrik · « **Reply #5 on:** June 01, 2018, 08:16:43 pm »

I've opened an issue for this in the LAV Filters issue tracker, if you know any other movies with this problem it might be helpful to know. Maybe something can be done about that.
https://github.com/Nevcairiel/LAVFilters/issues/208

jmone · « **Reply #6 on:** June 01, 2018, 08:34:53 pm »

Your a good man! These are the only three (so far) but I'll check over at MYCE if any others have surfaced. If you need any samples pls let me know and I can cut sample chunks of these three out.

Hendrik · « **Reply #7 on:** June 01, 2018, 10:02:25 pm »

I have Guardians myself, but an obvious sample from one of the others might help.

jmone · « **Reply #8 on:** June 01, 2018, 10:41:42 pm »

See PM for links.

TheShoe · « **Reply #9 on:** June 02, 2018, 07:44:36 am »

i can confirm GoG2 and Pirates of the Caribbean both exhibit this for me as well and at the same points as has been posted elsewhere. it is at least consistent it seems for everyone.

Hendrik · « **Reply #10 on:** June 02, 2018, 10:30:01 am »

I've posted a first test version with a new TrueHD bitstreaming module in the GitHub ticket.

https://github.com/Nevcairiel/LAVFilters/issues/208#issuecomment-394095164

It would be best to also provide any testing feedback there.

jmone · « **Reply #11 on:** June 02, 2018, 05:12:02 pm »

Nice work so far - feedback provided over at GitHub

jmone · « **Reply #12 on:** June 03, 2018, 07:02:36 am »

Nice work on the fix!

TheShoe · « **Reply #13 on:** June 03, 2018, 07:14:22 pm »

Tested the latest nightly and no longer having audio dropouts in Pirate of the Caribbean.

I'm using a Marantz AV7703.

Thanks for the fix!

TheShoe · « **Reply #14 on:** June 15, 2018, 10:21:24 pm »

Just started watching Game of Thrones, Season 6 episode 8 ("No One") and the opening theme has audio dropouts - multiple - same places every time.

I've only tried restarting and updating JRiver at this point. Still using the same version of lav posted in this thread.

Can anyone else confirm this?

After the initial opening theme for the episode, the audio (so far) seems fine.

Update:

Audio dropout also occurs during episode - so far just once.

TheShoe · « **Reply #15 on:** June 16, 2018, 12:19:05 am »

I'm going to re-rip that episode.

It's the only one of season 6 that has any audio drop outs.

jmone · « **Reply #16 on:** June 16, 2018, 01:27:21 am »

I'd wait a bit as there has been more fine tuning... but you will need MC 24.0.35 and a new LAV build. I've been driving Hendrik mad on some of the testing but looks like we have a rock solid combo coming out. All props to Hendrik!

jmone · « **Reply #17 on:** June 16, 2018, 02:05:36 am »

Quote

Game of Thrones, Season 6 episode 8

Yup I can confirm drop outs as well in the opening sequence. Log attached after the first drop but I don't see much of interest. Sorry Hendrik

Hendrik · « **Reply #18 on:** June 16, 2018, 03:33:35 am »

Is Game of Thrones even Atmos? I thought thats just normal TrueHD on normal Blu-rays (not UHD). Luckily I own all the seasons on Blu-ray already, and drops always in the same place are more fun then random things!

jmone · « **Reply #19 on:** June 16, 2018, 06:05:43 am »

There are a few different mixes around on std BD. My first few seasons are DTS-MA but Season 6 is Atmos and the drop is repeatable and in the same place (even with title mode particle).

TheShoe · « **Reply #20 on:** June 16, 2018, 06:09:35 am »

cool -glad you could repeat it. re-rip and it is still present.

season 6 is indeed atmos. i had no idea until jmone pointed it out some time ago.

still odd that the same opening sequence plays fine on all other episodes this season. maybe someone else was working the mixing board that day

thanks Hendrik!

Hendrik · « **Reply #21 on:** June 16, 2018, 06:12:16 am »

The drop-out even happens on the MKV rips I did of my Blu-rays. Must be something off in that stream. Seems to stop when the intro is over though.

jmone · « **Reply #22 on:** June 16, 2018, 06:17:31 am »

Damn... Watching the soccer. We just gave away a penalty. France 1 Oz 0.... Else I'd test to see if the ols lav also drops on these as the bitrate is not high.

jmone · « **Reply #23 on:** June 16, 2018, 06:19:08 am »

1 all!

Hendrik · « **Reply #24 on:** June 16, 2018, 06:19:22 am »

Nah it was a bug in the new LAV TrueHD code. Already fixed just now. New nightly appears .. tonight! 3am CEST or so.

jmone · « **Reply #25 on:** June 16, 2018, 06:21:32 am »

Another one down!

TheShoe · « **Reply #26 on:** June 16, 2018, 06:26:38 am »

that’s great! it does happen 2-3 times during the episode but i did not keep track where. next time i hear drop outs i’ll be sure to record the exact time.

should have also reported this was in an mkv container made with makemkv as well...

as a (former) developer i should know better about capturing these types of details

cheers and thanks Hendrik!

jmone · « **Reply #27 on:** June 16, 2018, 09:07:23 pm »

Tested and fixed in latest LAV Nightly

TheShoe · « **Reply #28 on:** June 17, 2018, 08:24:52 am »

Yup - just installed and indeed fixed.

Thanks Hendrik and jmone

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Author Topic: Atmos Drop Out Thread (when bitstreaming) (Read 3561 times)