AC-4 Audio?

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ferrellsl
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Re: AC-4 Audio?

Post by ferrellsl »

ferrellsl wrote: Mon Nov 01, 2021 3:08 pm Hi Martin. Where can we get the live version of your Android NextPVR client? The APK that I downloaded from your link complains that the demo has ended. I looked around on Google Play but wasn't sure which app was the correct one. Thanks in advance.
Hi Martin. Nevermind. I found the correct location here: https://forums.nextpvr.com/showthread.p ... #pid563403

I have noticed an issue with the pre-release version as well as your latest release so I suspect that Google has updated something recently on my Android boxes that breaks your app. At present, I can only view the ATSC3.0 channels. When I try to view other stations I get the following message: "Unsupported Video" but I do hear the audio.

hdmkv
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Re: AC-4 Audio?

Post by hdmkv »

Any way to convert AC-4 to AC-3 for recorded files?

ferrellsl
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Re: AC-4 Audio?

Post by ferrellsl »

hdmkv wrote: Mon Nov 01, 2021 5:09 pm Any way to convert AC-4 to AC-3 for recorded files?
Yes, you can transcode your files from AC-4 to AC-3, but why would you want to when there are native players for Windows available? Scroll back a page or two and download the QMplay2 app or the other lightweight video player that I provided download links for and playback your files unmodified. If you're dead set on transcoding your files, look inside the installation folders for either of these apps and you'll find a full distro of ffmpeg (64-bit Windows binaries, both exe's and DLL's) that supports AC-4 and streaming of ATSC3 channels. Just use the ffmpeg.exe in those folders to transcode your AC-4 files to AC-3.

I stopped using either player once I configured NextPVR to work with my tuner along with a custom build of Kodi that supports AC4 audio.

ppasteur
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Re: AC-4 Audio?

Post by ppasteur »

aaronwt wrote: Wed Oct 13, 2021 4:47 pm
ferrellsl wrote: Mon Oct 11, 2021 8:10 pm
sjm817 wrote: Sun Oct 10, 2021 9:00 am For all interested, I tried the NextPVR client that emveepee has mentioned in this thread. The audio works perfectly. For review, using HDHR backend and android TV client, I get a DD 5.1 container with only L&R channel audio. With his app, I get DD+ 5.1 with all channels working. I would really like to see the HDHR software get fixed to handle the audio properly.
Users need to also be aware that certain channels, even though they're using AC-4/HEVC/ATSC3.0, may not be broadcasting a DD5.1 signal. In the Phoenix area, I've noticed a real mix of audio formats on the new HEVC channels ranging from AAC to AC-4/2-channel, to AC-4/6-channel.



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I've been recording and watching ATSC OTA HD content for over twenty years now. Since Summer 2001. During that time I've seen a multitude of different audio channel options broadcast in Dolby DIgital. I've seen DD 1.0, 1.1, 2.0, 2.1, 3.0, 3.1, 4.0, 4.1, 5.0, and 5.1 broadcast at one time or another. In the DC and Baltimore area.
Maybe folks didn't read my entire post well. The HDHR client on my LG OLED over ARC to the Denon X6400H produces 5.1 channels of output from the same 4 ATSC 3.0 stations here that produce 2 channels on other clients.
I also have been recording and listening to TV audio for close to 20 years. I also am very aware that stations have sent various channel numbers inside of a 5.1 container.
The point is that the locals are sending a full 5.1. But the HDHR APP for Android TV and the Apple TV 4K (at least, and I think the Windows client as well) is stripping out the surround channels.
I responded to another user who is having the same issues in a different market. I am just saying that it bears looking into and not dismissed out of hand by blaming the content of the incoming signal. Which in this case is not to blame.
I would also like to know if others using the above devices in different markets have experienced the same thing. I did not really notice this until it was brought to my attention and I actually did some testing.
I have an idea that there are others having the same issue.
So, now that we accept that stations can send various numbers of channels , how about accepting that they can send full 5.1 and have the process used in the HDHR client decode from AC4 incorrectly. Or maybe decoded properly but screwed up the conversion/re-encoding to AC3.
Anyway, I would appreciate it if other people did some close listening to see if this is happening to more than the 2 people that have reported the issue.

tmm1
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Re: AC-4 Audio?

Post by tmm1 »

Which market are you in?

sjm817
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Re: AC-4 Audio?

Post by sjm817 »

A little update. TV received an update which I think changed things a bit.
For review, my issue on Android TV is 2.0 audio coming through embedded in a 5.1 AC3 container with other channels silent which is really bad when you have a surround system. I have a 2021 Sony X90J which has built in ATSC 3.0 tuner. It receives the 5.1 AC4 just fine, transcodes to EAC3 (not AC3) and sends it to AVR. Works perfect. To be clear, I have an 5.1 AC4 feed. It is not a broadcast issue. I also tested a Next PVR beta client that used the HDHR tuner. Setting to to HW decoding did sent AC4 5.1 to the TV which decoded it to EAC3 5.1. It is the only way I have been able to get 5.1 AC4 using HDHR

With the update, if I have AC3 passthrough on, nothing changed. 2.0 in a 5.1 AC3. Here is what may be different. If I turn AC3 passthrough off, I now get a 2.0 in a 2.0 DD+ signal showing up on the AVR. There is no way for me to see in the TV if the incoming signal was AC4 which got converted to DD+ or if was DD+ to begin with. I can see that on an antenna input but not the HDHR input.

Here is what I am looking for and I thought was on the way: AC4 passthrough. Just need the HDHR to pass the AC4 though to my TV and let it decode it. Is this something coming? A remote decoding service is not at all what I need.

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Re: AC-4 Audio?

Post by nickk »

sjm817 wrote: Tue Nov 23, 2021 9:55 pm A little update. TV received an update which I think changed things a bit.
For review, my issue on Android TV is 2.0 audio coming through embedded in a 5.1 AC3 container with other channels silent which is really bad when you have a surround system. I have a 2021 Sony X90J which has built in ATSC 3.0 tuner. It receives the 5.1 AC4 just fine, transcodes to EAC3 (not AC3) and sends it to AVR. Works perfect. To be clear, I have an 5.1 AC4 feed. It is not a broadcast issue. I also tested a Next PVR beta client that used the HDHR tuner. Setting to to HW decoding did sent AC4 5.1 to the TV which decoded it to EAC3 5.1. It is the only way I have been able to get 5.1 AC4 using HDHR

With the update, if I have AC3 passthrough on, nothing changed. 2.0 in a 5.1 AC3. Here is what may be different. If I turn AC3 passthrough off, I now get a 2.0 in a 2.0 DD+ signal showing up on the AVR. There is no way for me to see in the TV if the incoming signal was AC4 which got converted to DD+ or if was DD+ to begin with. I can see that on an antenna input but not the HDHR input.

Here is what I am looking for and I thought was on the way: AC4 passthrough. Just need the HDHR to pass the AC4 though to my TV and let it decode it. Is this something coming? A remote decoding service is not at all what I need.
Are you running the HDHomeRun app directly on the Sony TV, or on something else that is connected to the Sony TV?

sjm817
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Re: AC-4 Audio?

Post by sjm817 »

Directly on Sony TV. I also have a Shield (2017 version). Shield is connected to AVR. Just tried it. Shield decodes the audio to PCM
Shield: AC3 passthrough off
ATSC 1.0 = Multi Channel PCM 5.1 with all audio present
ATSC 3.0 = Multi Channel PCM 5.1 with only L&R

Sony:
AC3 Passthrough off
ATSC 1.0 = DD+ 2.0
ATSC 3.0 = DD+ 2.0

nickk
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Re: AC-4 Audio?

Post by nickk »

We have a number of improvements that will be released in beta late next week.

Note that there is no concept of AC4 passthrough - anything that does AC4 will have to convert it to something useful before delivering it over HDMI or a digital audio path. Sony outputting DD+ makes sense.

App running on the Sony TV - waiting on a new Sony TV for our test environment to confirm but if Sony did things right you should get 5.1 sound with the new app release.

App running on the Shield - this will use our new transcode service and output audio as stereo PCM or stereo AC3 to your TV or sound system. We plan to add 5.1 support in the future.

Nick

sjm817
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Re: AC-4 Audio?

Post by sjm817 »

Thanks Nick. That sounds really promising. Im happy to test it out and give you feedback. I assume there will be an announcement here somewhere? NV Shield support I dont care much about but Im sure there are plenty that do.

FYI if it helps with what you are looking at with Sony device support. Its not just the 2021 TVs with ATSC3 that support AC4 audio, That was added in 2019 models but not sure if all models had it. Thats 3 model years which this would work with.

nickk
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Re: AC-4 Audio?

Post by nickk »

We are not seeing AC4 as a supported codec in Android on Sony TVs even though it must have the codec for ATSC 3.0 TV content.

As a comparison the Sony XQ-AS62 smartphone reports AC4 codec support in Android.

sjm817
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Re: AC-4 Audio?

Post by sjm817 »

Sony in 2019 broke out "Dolby Audio" into supported formats, but iin 2020 seemed to stop doing that

Here is a2019 X950G which I own, and I have sent AC-4 via Next PVR beta client which it decoded to DD+
https://www.sony.com/electronics/suppor ... ifications
Sound (Processing)
SOUND MODES
Standard, Dialog, Theater, Music, Sports, Dolby Audio

DOLBY AUDIO FORMAT SUPPORT
Dolby™ Audio (Dolby™ Digital, Dolby™ Digital Plus, Dolby™ AC-4)

DTS AUDIO FORMAT SUPPORT
DTS Digital Surround

The basically identical 2020 950H just says "Dolby Audio without the format details"
https://www.sony.com/electronics/suppor ... ifications
DOLBY AUDIO FORMAT SUPPORT
Dolby™ Audio, Dolby™ Atmos

DTS AUDIO FORMAT SUPPORT
DTS Digital Surround

The 2021 A90J with built in ATSC3 which I also own On this TV with antenna input shows that format is AC-4 and AVR shows DD+
https://www.sony.com/en-ao/electronics/ ... ifications

DOLBY AUDIO FORMAT SUPPORT
Dolby™ Audio, Dolby™ Atmos

I have tested with what I have available to me. I can say for certain that the beta NextPVR client using HDHR tuner when set to hardware decoding resulted in a 5.1 DD+ coming from the TV to the AVR input with all channels working. It is the only configuration i tried that did that.
Last edited by sjm817 on Thu Nov 25, 2021 5:54 pm, edited 1 time in total.

nickk
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Re: AC-4 Audio?

Post by nickk »

Can you please turn on "send diagnostic information" in the HDHomeRun app settings menu on the A90J, restart the app, then post back with the device ID of your HDHomeRun

Nick

sjm817
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Re: AC-4 Audio?

Post by sjm817 »

Sure. Do you want AC3 passthrough on or off or does it matter?

nickk
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Re: AC-4 Audio?

Post by nickk »

Doesn't matter. Please run the test on the A90J.

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