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Shield TV Emby App surround sound is downmixed locally ... no DTS/TRUEHD...


Go to solution Solved by Racerx1977,

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Posted

This seems to be an issue on my 2015 Shield connected to a Sonos Beam following the upgrade to Shield Experience 8.2.0.

Beta ATV app v1.8.28.

 

  • 1 month later...
Posted
On 27/08/2020 at 22:56, CBers said:

This seems to be an issue on my 2015 Shield connected to a Sonos Beam following the upgrade to Shield Experience 8.2.0.

Beta ATV app v1.8.28.

 

Still no update from nvidia 🙄

  • Like 1
  • 2 weeks later...
Posted

Received another hotfix (32.8.435.17), but still no fix for the "local downmix" issue. 

1768043941_Systemupgrade_20201013_121533.thumb.png.c96a9d30bf871812ad7e83950cdccf1b.png

Posted (edited)

@ebr Just submitted in-app logs (user=Master) as I tried to get a "local downmix" video to be transcoded, via the Playback Correction option, so as to try and get the AC3 audio to play, but the remux was from AC3 to AAC.

21:26:52.569 Stream mapping:
21:26:52.569   Stream #0:0 -> #0:0 (copy)
21:26:52.569   Stream #0:1 -> #0:1 (ac3 (native) -> aac (native))
21:26:52.569   Stream #0:2 -> #1:0 (subrip (srt) -> webvtt (native))
21:26:52.569   Stream #0:0 -> #1:1 (copy)
21:26:52.569 Press [q] to stop, [?] for help

Any ideas why please? 

 

Edited by CBers
Posted

If you do playback correction on something that is already decoding audio inside the app, its going to assume that the audio has to be stripped down to its most primitive form possible to ensure proper playback.

Posted
25 minutes ago, ebr said:

If you do playback correction on something that is already decoding audio inside the app, its going to assume that the audio has to be stripped down to its most primitive form possible to ensure proper playback.

So its the app that is doing "local downmix" and not the Shield? 

Posted
14 minutes ago, CBers said:

So its the app that is doing "local downmix" and not the Shield? 

If you have another Android TV device that's not a shield it would be pretty easy to find out. :)

Posted
9 minutes ago, cayars said:

If you have another Android TV device that's not a shield it would be pretty easy to find out. :)

Please don't cloud the question. 

SFN shows Direct Play, but has "local downmix" in brackets. 

I need to know if this is the app or the Shield. 

Thanks. 

Posted

Sorry CBers wasn't my intention.  I thought you might have another Android TV device (do you?) and could have gotten an answer quicker trying it, then waiting for an answer.

 

Posted (edited)

Local downmix implies the client is doing the work. When you use playback correction the app doesn't understand was there a problem with the video or the audio? So when you use it on Android TV this must assume to change video playback method and at the same time it must assume that the audio must be stripped down. It doesn't know why you hit playback correction was it to correct the video or audio? So both changes take place. But "local" part of the downmix to me means the client is doing the heavy lifting on the audio conversion.

On the Roku for example there is no possible local downmix. Therefore the audio can never be converted with playback correction on the Roku only the video playback method changes. The user must change Roku audio settings and get the server transcoding the audio.

Edited by speechles
Posted

Problem is it will show this "local downmix" just playing and not after hitting playback correction, plus it will correct audio from a format it could already play.

Posted

So nothing from @ebr.

The item direct plays, but SFN says "local downmix", which I thought had only started since the last Shield update, which is why I thought it was the Shield doing it, but now you are all saying it's the app, which is confusing, seeing as it has only done it recently. 

Previously for the last 3 years, any audio not playable on my (Sonos Beam) soundbar would get remuxed to AC3, but now everything is AAC (stereo as seen in the Sonos app). 

If this is the app doing it, then I want to know why, and if the app can be regressed to get the audio to work as it used to. 

With the audio being received by the soundbar as stereo, I have to crank the volume up to be able to hear it. 

My other Shield, connected to an LG soundbar which has better audio capabilities, does not have any issue and everything is Direct Play with HD audio. 

I just need to understand what this "local downmix" is and why it's happening.

Thanks. 

Posted
6 hours ago, CBers said:

I just need to understand what this "local downmix" is and why it's happening.

It means the app is decoding the audio itself.  Why it is happening is "it depends" but, I believe we identified earlier that in this case, your sound bar is only reporting support for stereo audio so, instead of involving the server, we just do that in the app.

Just looked at your latest log and, yes, that is still the case:

10-13 21:26:31.865 30543 30543 I System.out: Reported device audio support is: ,aac_latm,mp4a_latm
...
10-13 21:26:31.866 30543 30543 I System.out: Max Audio Channels reported as: 2

 

Posted
59 minutes ago, ebr said:

It means the app is decoding the audio itself.  Why it is happening is "it depends" but, I believe we identified earlier that in this case, your sound bar is only reporting support for stereo audio so, instead of involving the server, we just do that in the app.

Just looked at your latest log and, yes, that is still the case:


10-13 21:26:31.865 30543 30543 I System.out: Reported device audio support is: ,aac_latm,mp4a_latm
...
10-13 21:26:31.866 30543 30543 I System.out: Max Audio Channels reported as: 2

 

The Sonos Beam supports Dolby D, so don't understand why this is happening. 

This is why I, and many other people, have asked for an override to pass through the audio. 

Posted
17 minutes ago, CBers said:

The Sonos Beam supports Dolby D, so don't understand why this is happening. 

This is why I, and many other people, have asked for an override to pass through the audio. 

Doesn't the Shield itself allow you to "roll your own support" for codecs? That is what you can do in the Roku. With Roku you use "Auto" on HDMI-Audio and it self detects or you can choose "DD" or "DTS, DD" or "DTS, DD+". When choosing directly rather than Auto you may not get sound. It might be the sound of silence.

Does the shield offer something similar in the settings of itself?

Posted
1 hour ago, CBers said:

The Sonos Beam supports Dolby D, so don't understand why this is happening. 

This is why I, and many other people, have asked for an override to pass through the audio. 

Interestingly, using version 0.112 of the Samsung ET app, I get Dolby Digital received on the Sonos Beam, so why isn't the ATV app able to do it. 

It is also Direct Playing it, so no transcode/remux. 

 

Posted
1 hour ago, speechles said:

Doesn't the Shield itself allow you to "roll your own support" for codecs? That is what you can do in the Roku. With Roku you use "Auto" on HDMI-Audio and it self detects or you can choose "DD" or "DTS, DD" or "DTS, DD+". When choosing directly rather than Auto you may not get sound. It might be the sound of silence.

Does the shield offer something similar in the settings of itself?

Been there, done all of that. 

 

Posted (edited)

@ebr I have just installed a very old version of the ATV app, v1.4.6, and guess what, I now have Dolby Digital audio playing through my Sonos Beam, as the audio is being remuxed from EAC3 and DTS down to DD.

So, can you out back into the app what you have obviously removed at some point recently please. 

I have attached 2 remux logs and have just submitted in-app logs (user=Master) for your reference. 

Thanks. 

 

 

ffmpeg-remux-24721147-e566-4db7-9fa0-54bb796a70c4_1.txt ffmpeg-remux-c19cfa35-6bfc-45f9-b4db-36ca125f9165_1.txt

Edited by CBers
  • Like 2
Posted

I'm seeing strange audio and reported behavior as well.  I'm watching Fox News at the moment and the app/SFN is showing local downmix for audio but direct play and the server is showing transcoding.

There is no need to downmix the audio for my Samsung TV nor sound system through the Shield TV.  Also I've lost the ability to change the audio track in live TV but CC still works.  Actually I doubt there is ever a reason to downmix audio from an ATSC 1.0 TV broadcast as the TV would be pretty lousy to not be able to support the streamed sound included. :)

  • Like 1
Posted
16 minutes ago, CBers said:

 I have just installed a very old version of the ATV app, v1.4.6, and guess what, I now have Dolby Digital audio playing through my Sonos Beam, as the audio is being remuxed from EAC3 and DTS down to DD. 

@ebr I upgraded a step at a time, from v1.4.6, through v1.5.53, v1.7.x.x, v1.8.0.0, v1.8.15, v1.8.30, v1.8.35 and finally to v1.8.41 (the latest) and I still have DD playing on my Sonos Beam all the time.

So, I wonder if it was a bug in the app from a long time ago, that uninstalling and reinstalling an old version cleared it? 

So glad I keep a library of the old versions of the app. 

  • Like 1
Posted

Sorry guys but maybe i missed something but what is the solution to this issue, because i cant seem to find it?

Posted
2 hours ago, Dwarf said:

Sorry guys but maybe i missed something but what is the solution to this issue, because i cant seem to find it?

Not sure there is one to be honest. 

I thought I had a fix, but it still doesn't work. 

Posted
37 minutes ago, CBers said:

Not sure there is one to be honest. 

I thought I had a fix, but it still doesn't work. 

Allright, then there is nothing else to do than wait. Hope there will be a solution eventually :)

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