AC-4 Audio?

ATSC 3.0 Forum
Post Reply
CBme
Posts: 147
Joined: Thu Oct 15, 2020 2:15 pm
x 13

Re: AC-4 Audio?

Post by CBme »

nickk wrote: Thu Dec 17, 2020 11:47 pm
CBme wrote: Thu Dec 17, 2020 11:05 pm Same at the moment, no ac4 audio on my shield pro but other channels are fine. Receiver just says stereo for me. App version is 12-15 though, and I uninstalled and reinstalled, so I assume that means the update Nick is referring too isn't on live on the play store yet.
For audio to work you need a 2019+ (3rd generation) Shield or for older models you need to connect to a receiver or TV that supports Atmos via HDMI.

Nick
Yup, that is what I have. Actually just got it early this week as amazon had the Shield Pro on sale.
Tried a full reboot of the system and no change.
Last edited by CBme on Mon Jan 04, 2021 10:14 pm, edited 1 time in total.

talkenrain
Posts: 32
Joined: Fri May 18, 2012 1:28 pm
x 5

Re: AC-4 Audio?

Post by talkenrain »

nickk wrote: Thu Dec 17, 2020 11:47 pm For audio to work you need a 2019+ (3rd generation) Shield or for older models you need to connect to a receiver or TV that supports Atmos via HDMI.

Nick
I believe the name “Shield Pro” implies it’s the full sized 3rd gen unit (mine is). Mine is connected via HDMI to a pre/processor that fully supports Atmos 7.2.4.

darcilicious
Posts: 182
Joined: Thu Sep 06, 2018 3:08 pm
Location: Portland, OR
x 3

Re: AC-4 Audio?

Post by darcilicious »

NedS wrote: Fri Dec 04, 2020 9:00 pm
talkenrain wrote: Fri Dec 04, 2020 7:45 pm
nickk wrote: Thu Dec 03, 2020 7:12 pm We found and fixed a problem that was preventing AC4 audio from working on ARM based platforms that support AC4 audio.

There will be Android, iOS, and AppleTV app releases in the next few days.

Nick
My experience using release 20201204 on AppleTV 4k:
The audio is much improved but still nowhere near what it should be. Im in the Portland market. Audio seems to be off center (ABC, CBS channels; left audio dominates, NBC channel; the right audio dominates, All channels, the audio fidelity is not what it should be.

I also have an LG OLED with the HD app running on it. Using the same audio gear while watching/listening the same channels, The audio from the LG is 1000% better, no balance issues and really preforms great compared to the same app on the AppleTV.
That sounds like a channel mapping issue (what tracks are going to what speakers), which should be fairly easy to correct. The important part is that audio is working at all (which means the AC-4 decoding is working). We will have the dev team look into the audio mapping and try to get that fixed ASAP.
I don’t detect any improvement in the channel mapping in the latest release (20201216) for the Apple TV 4K.

nickk
Silicondust
Posts: 16751
Joined: Tue Jan 13, 2004 9:39 am
x 89

Re: AC-4 Audio?

Post by nickk »

2019/gen3 Nvidia Shield Pro problem found and fixed.

Please restart the app.

Nick

talkenrain
Posts: 32
Joined: Fri May 18, 2012 1:28 pm
x 5

Re: AC-4 Audio?

Post by talkenrain »

nickk wrote: Fri Dec 18, 2020 10:30 am 2019/gen3 Nvidia Shield Pro problem found and fixed.

Please restart the app.

Nick
Hi Nick, Just retried. I now get audio out of only the left front channel. still crashes when tuned to Portlands KGW 8.1 (NBC). Turned on diagnostic info. Unit #10808FA2

CBme
Posts: 147
Joined: Thu Oct 15, 2020 2:15 pm
x 13

Re: AC-4 Audio?

Post by CBme »

nickk wrote: Fri Dec 18, 2020 10:30 am 2019/gen3 Nvidia Shield Pro problem found and fixed.

Please restart the app.

Nick
Getting audio again now. It is coming out as stereo to my non-atmos receiver and for ABC and CBS it is only coming out of the left side (like talkenrain mentioned) and is very quiet. (seattle stations)
Edit: Realized that ABC and CBS are on the same Ch# which might or might not be anything. It seems to be putting the front channels in the left and the rear or surrounds in the right. Same on PC, Phone, xbox and Shield.
Last edited by CBme on Mon Jan 04, 2021 10:11 pm, edited 1 time in total.

FFantin
Posts: 11
Joined: Wed Oct 14, 2020 10:02 pm
Location: Michigan, USA

Re: AC-4 Audio?

Post by FFantin »

I'd suggest not buying the Roku Ultra 2020. I just got it today under the impression that it does support AC-4, but it doesn't work and I'm going to return the device immediately.

Dartman
Posts: 81
Joined: Sat Dec 10, 2011 12:29 pm

Re: AC-4 Audio?

Post by Dartman »

It has the AC4 support but not in the package that they use for the new tuner I guess yet. I bought one too but it was on a good black Friday sale so I'm keeping it for the other updates it got and hoping eventually it gets a update to work. It has been mentioned in threads here before when I asked about it right after I ordered it.

Aubury
Posts: 2
Joined: Mon Dec 21, 2020 9:20 pm

Re: AC-4 Audio?

Post by Aubury »

I'm running into a problem into a problem with my Nvidia Shield Pro and the HDHomeRun app. When I open the app on the Shield and tune to an ATSC 3.0 channel, it will play for a few seconds and then the app will crash. The video will start and run for a couple of seconds, then I will get audio for about half a second before the app crashes altogether. My app version is 20201217 and my Connect 4k version is 20201030. I get similar behavior on my Pixel 3XL (except no audio at all, which I assume would be expected for now) with the behavior of the crashes. If I start a stream from my Plex server I can watch the video with no problems, but obviously don't have audio since Plex doesn't support AC-4 yet. Also, this behavior doesn't happen on the subchannels that aren't ATSC 3.0.

It's been a mild annoyance since my local broadcasters decided to all start broadcasting ATSC 3.0 at the same time and I can't switch the channels back to ATSC 1.0 until SD releases the patch enabling that. ;)

Any ideas on what might be causing this and remedies is greatly appreciated! Thank you!!

jmcgeejr
Posts: 36
Joined: Sat Jun 16, 2018 5:00 pm
x 1

Re: AC-4 Audio?

Post by jmcgeejr »

Read through this and I couldnt find (or missed), I am able to watch tv with my shield pro 2019 model as it supports AC4, I was wondering what's the plan for devices like fire tv cube and fire tv stick 4k and such? I saw that if the device supports DD+ that it should support AC4 as well (no idea how true that is really). Just curious. Thanks for everything!

darcilicious
Posts: 182
Joined: Thu Sep 06, 2018 3:08 pm
Location: Portland, OR
x 3

Re: AC-4 Audio?

Post by darcilicious »

jmcgeejr wrote: Tue Dec 22, 2020 1:02 am I saw that if the device supports DD+ that it should support AC4 as well (no idea how true that is really).
Everything I have read from Silicondust says if the device supports Atmos then it should support AC4, see this post for example: viewtopic.php?f=133&t=74253&p=363618#p363618

DD+ is not the same as Atmos.

mooninite
Posts: 22
Joined: Wed Dec 19, 2018 9:13 pm
x 4

Re: AC-4 Audio?

Post by mooninite »

darcilicious wrote: Tue Dec 22, 2020 2:50 am
jmcgeejr wrote: Tue Dec 22, 2020 1:02 am I saw that if the device supports DD+ that it should support AC4 as well (no idea how true that is really).
Everything I have read from Silicondust says if the device supports Atmos then it should support AC4, see this post for example: viewtopic.php?f=133&t=74253&p=363618#p363618

DD+ is not the same as Atmos.
Wrong.

Atmos is a metadata extension to AC-3 and AC-4. It's not audio data. "Atmos" is not a standard of audio - it is not AC-4. I wish Nick would stop using Atmos in this way.

"DD" is AC-3 - and can contain Atmos data
"DD+" is a minor update to AC-3 with support for more bitrates. It's also known as E-AC-3. It can also contain Atmos data.

darcilicious
Posts: 182
Joined: Thu Sep 06, 2018 3:08 pm
Location: Portland, OR
x 3

Re: AC-4 Audio?

Post by darcilicious »

mooninite wrote: Tue Dec 22, 2020 10:54 am
darcilicious wrote: Tue Dec 22, 2020 2:50 am
jmcgeejr wrote: Tue Dec 22, 2020 1:02 am I saw that if the device supports DD+ that it should support AC4 as well (no idea how true that is really).
Everything I have read from Silicondust says if the device supports Atmos then it should support AC4, see this post for example: viewtopic.php?f=133&t=74253&p=363618#p363618

DD+ is not the same as Atmos.
Wrong.

Atmos is a metadata extension to AC-3 and AC-4. It's not audio data. "Atmos" is not a standard of audio - it is not AC-4. I wish Nick would stop using Atmos in this way.

"DD" is AC-3 - and can contain Atmos data
"DD+" is a minor update to AC-3 with support for more bitrates. It's also known as E-AC-3. It can also contain Atmos data.
The point is, in the context of this discussion, if your hardware device doesn't list ATMOS as supported under audio (e.g. like Apple does for the iPad Pro but does NOT for the iPad 8th gen or iPad Air 4th gen), then AC4 won't be supported in the HDHR app. So says Silicondust. My own experience has born this out.

Gwilly7
Posts: 10
Joined: Tue May 08, 2018 4:01 pm
x 2

Re: AC-4 Audio?

Post by Gwilly7 »

Denver just got the updated channels yesterday and of course neither my Sony X900H or my Tivo Stream 4k can play the sound. My Sony has an ATSC 3.0 tuner inside, but that is coming with a future update. Guessing the AC-4 support will not come until that update, hopefully I am wrong.

NedS
Silicondust
Posts: 2047
Joined: Mon Dec 10, 2018 12:38 pm
x 52

Re: AC-4 Audio?

Post by NedS »

mooninite wrote: Tue Dec 22, 2020 10:54 am Wrong.

Atmos is a metadata extension to AC-3 and AC-4. It's not audio data. "Atmos" is not a standard of audio - it is not AC-4. I wish Nick would stop using Atmos in this way.

"DD" is AC-3 - and can contain Atmos data
"DD+" is a minor update to AC-3 with support for more bitrates. It's also known as E-AC-3. It can also contain Atmos data.
Hardware and software licensed for ATMOS will be licensed for AC-4. Atmos is the feature that gets advertised.

Post Reply