AC-4 Audio?

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ferrellsl
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Re: AC-4 Audio?

Post by ferrellsl »

I've completed a build of the QMPlay2 app for 64-bit Windows that supports HEVC with AC-4 audio. See https://github.com/zaps166/QMPlay2 for more info about QMPlay2.

QMPLAY2 supports playback of local files as well as URL streams such as those from your HDHomeRun 4k tuners. It also has an equalizer, FFT spectrum, supports subtitles and lyrics.

This is a portable build. Once you've extracted the app to your hard drive, run the QMPlay2.exe but do not allow it to update itself as this will break AC-4 audio. Go to Options->Settings and remove the checkmark that says "Automatically check and download updates".

No, I will not build a Linux/MacOS version nor will I build a version for 32-bit Windows.

You can download this modified version of QMPLAY2 from here: https://www.dropbox.com/s/nidx6vaquxx7j ... 2.zip?dl=0

Image
Last edited by ferrellsl on Wed Sep 08, 2021 9:54 pm, edited 1 time in total.

ferrellsl
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Re: AC-4 Audio?

Post by ferrellsl »

For folks who want something a bit more light weight than QMPlay2, you can try this player. It's barebones and plays local files and URL streams (with HEVC/AC-4 audio support of course). This is another 64-bit Windows app and is based on the the player found here: https://github.com/yundiantech/VideoPlayer

When feeding it a URL, be patient and wait a bit for the video to start playing. It can take up to 20 seconds before the stream plays after providing a working URL.

Again, if you want a Linux/MacOS version or a 32-bit Windows build you're welcome to roll your own from the sources at github.

I use NextPVR to schedule my HEVC/AC4 recordings from my Silicon Dust tuner and use this player or QMPlay2 for playback since Windows doesn't have native AC-4 audio support.

You can download the installer for this light weight player here: https://www.dropbox.com/s/cx2tm3f4i4whg ... p.exe?dl=0

jasonl
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Re: AC-4 Audio?

Post by jasonl »

bobchase wrote: Wed Sep 08, 2021 10:54 am
jasonl wrote: Tue Sep 07, 2021 6:09 pm
bobchase wrote: Mon Sep 06, 2021 11:47 am
112.1 (NBC) is down due to an interstation connection problem.
110.1 (FOX) should come in for you as it is working for Silicon Dust tuners as well as the TV's.
I'm curious, what format are the video and audio in when bouncing from station to station?
121.1 is being sent out 1080p60
110.1 is being sent at 720p60
I'm asking about the inter-station link before it actually gets encoded for broadcast. Is KPNX sending out 1080i in some uncompressed HD-SDI type format over fiber that eventually reaches KASW, where it gets upconverted to 1080p and encoded to HEVC? Some sort of intermediate compression format? I remember the the later days of analog TV when there was a fiber loop running around town linking up all the major stations plus Cox (or was it still Dimension?) so that cable viewers got a cleaner feed that didn't go down when a transmission line burned out or someone had to relamp their tower.

bobchase
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Re: AC-4 Audio?

Post by bobchase »

jasonl wrote: Thu Sep 09, 2021 5:30 pm
bobchase wrote: Wed Sep 08, 2021 10:54 am
jasonl wrote: Tue Sep 07, 2021 6:09 pm
I'm curious, what format are the video and audio in when bouncing from station to station?
121.1 is being sent out 1080p60
110.1 is being sent at 720p60
I'm asking about the inter-station link before it actually gets encoded for broadcast. Is KPNX sending out 1080i in some uncompressed HD-SDI type format over fiber that eventually reaches KASW, where it gets upconverted to 1080p and encoded to HEVC? Some sort of intermediate compression format? I remember the the later days of analog TV when there was a fiber loop running around town linking up all the major stations plus Cox (or was it still Dimension?) so that cable viewers got a cleaner feed that didn't go down when a transmission line burned out or someone had to relamp their tower.
I can't tell you the amount of compression or the datarate between KPNX and KSAZ but it certainly wouldn't be uncompressed as there is only about 100 Mbps available to move a 1.5 Gbps feed. After KPNX is encoded to DASH, along with KSAZ and KUPT, they are then sent over to KASW for ROUTE encapsulation, signaling and scheduling.

DaveNLR
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Re: AC-4 Audio?

Post by DaveNLR »

Rak313 wrote: Sun Aug 08, 2021 9:38 am Ive read through this entire thread. But I don't see a current list of TVs, or devices (that can successfully decode ATSC 3.0 audio) that was suggested early on in the thread.

Specifically I like to know about ipad, iphone, fire stick (eg firestick 4k), and Sony A80j 4k tv.
The Sony A80J, and A90j, and X95J have a built in ATSC 3.0 tuner and can decode the audio.
I believe the HDHomeRun app decodes the audio on any device it is running on, regardless if the device supports AC4. It should output AC3.
My only remaining issue is it will not work with my Plex DVR, since plex does not recognize AC4 so I have to record on the ATSC 1.0 channels.

ferrellsl
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Re: AC-4 Audio?

Post by ferrellsl »

:--)

ferrellsl
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Re: AC-4 Audio?

Post by ferrellsl »

DaveNLR wrote: Fri Sep 17, 2021 8:56 pm
Rak313 wrote: Sun Aug 08, 2021 9:38 am Ive read through this entire thread. But I don't see a current list of TVs, or devices (that can successfully decode ATSC 3.0 audio) that was suggested early on in the thread.

Specifically I like to know about ipad, iphone, fire stick (eg firestick 4k), and Sony A80j 4k tv.
The Sony A80J, and A90j, and X95J have a built in ATSC 3.0 tuner and can decode the audio.
I believe the HDHomeRun app decodes the audio on any device it is running on, regardless if the device supports AC4. It should output AC3.
My only remaining issue is it will not work with my Plex DVR, since plex does not recognize AC4 so I have to record on the ATSC 1.0 channels.
If you look inside the installation directory for the HDHomeRun app on your Windows system, you can make some inferences. On my system, that directory is located at:

C:\Program Files\WindowsApps\EF712BA7.HDHomeRunDVR_1.1.324.0_x64__23nna27hyxhag

In that folder you will also see some DLL's in addition to the HDHomeRun app and support files.

Here is the listing of my folder, notice the following DLL files: avcodec-58.dll, avdevice-58.dll, avfilter-7.dll, avformat-58.dll, avutil-56.dll, swresample-3.dll and swscale-5.dll.
These are ffmpeg DLL files and it implies that ffmpeg has been modified to decode ATSC3/AC-4 streams. Ffmpeg is licensed under GPL which has its own implications.

09/08/2021 06:51 AM 20,147 AppxBlockMap.xml
09/08/2021 06:51 AM 6,066 AppxManifest.xml
09/08/2021 06:51 AM <DIR> AppxMetadata
09/08/2021 06:51 AM 10,943 AppxSignature.p7x
09/08/2021 06:51 AM <DIR> Assets
09/08/2021 06:51 AM 3,564,544 avcodec-58.dll
09/08/2021 06:51 AM 42,496 avdevice-58.dll
09/08/2021 06:51 AM 4,493,824 avfilter-7.dll
09/08/2021 06:51 AM 297,472 avformat-58.dll
09/08/2021 06:51 AM 755,200 avutil-56.dll
03/18/2017 07:35 PM 65,720 clrcompression.dll
09/08/2021 06:51 AM 15,872 HDHomeRunView.ControlApi.winmd
09/08/2021 06:51 AM 3,742,720 HDHomeRunView.dll
09/08/2021 06:51 AM 16,384 HDHomeRunView.exe
09/08/2021 06:51 AM 708,096 HDHomeRunView.MediaStream.dll
07/15/2021 10:35 PM 9,216 HDHomeRunView.MediaStream.winmd
09/08/2021 06:51 AM 212,480 HDHomeRunView.VolumeControl.dll
07/15/2021 10:35 PM 4,608 HDHomeRunView.VolumeControl.winmd
05/05/2021 01:10 PM 2,855 HDHomeRunView.xr.xml
09/08/2021 06:51 AM 5,344 resources.pri
09/08/2021 06:51 AM 182,272 swresample-3.dll
09/08/2021 06:51 AM 740,352 swscale-5.dll
09/08/2021 06:51 AM <DIR> _Resources
21 File(s) 14,896,611 bytes

Anyway, going back to one of my previous posts, if you really want to record the ATSC3 programs instead of the ATSC1 channels, you can use NextPVR (or even wget) to schedule and record them and then use QMPlay2 or the other player I linked earlier for playback. Initially I was transcoding my ATSC3 recordings for AC-3 playback but this became a chore so I decided to modify QMPlay2 and the other lightweight video player to support AC-4. You can get the lightweight player here: https://www.dropbox.com/s/cx2tm3f4i4whg ... p.exe?dl=0
And you can get QMPlay2 here: https://www.dropbox.com/s/nidx6vaquxx7j ... 2.zip?dl=0

If you prefer to use ffmpeg.exe instead of these players you can find the ffmpeg.exe and the necessary DLL files inside the zip archives for each player.

autodidact
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Re: AC-4 Audio?

Post by autodidact »

DaveNLR wrote: Fri Sep 17, 2021 8:56 pm
Rak313 wrote: Sun Aug 08, 2021 9:38 am Ive read through this entire thread. But I don't see a current list of TVs, or devices (that can successfully decode ATSC 3.0 audio) that was suggested early on in the thread.

Specifically I like to know about ipad, iphone, fire stick (eg firestick 4k), and Sony A80j 4k tv.
The Sony A80J, and A90j, and X95J have a built in ATSC 3.0 tuner and can decode the audio.
I believe the HDHomeRun app decodes the audio on any device it is running on, regardless if the device supports AC4. It should output AC3.
My only remaining issue is it will not work with my Plex DVR, since plex does not recognize AC4 so I have to record on the ATSC 1.0 channels.
I have a Sony A90J TV. It plays the AC4 ATSC 3.0 audio just fine through it's internal tuner. With live or recorded content from my HDHomeRun/SERVIO, there is no audio from ATSC 3.0 broadcasts. The audio from ATSC 1.0 broadcasts is fine.

hokietima
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Re: AC-4 Audio?

Post by hokietima »

Wow, I'm having flashbacks to my early Home Theater Computer days when everyone was trying to figure out how to play AC-3 audio. Remember the AC3Filter plugin?

Just got my HDHomeRun Flex 4K. Here is my experience with ATSC 3.0 AC-4 audio:
2017 Shields: Audio plays on my 2017 Shields fine when hooked up to a Dolby Atmos capable AVR (Denon AVR-X6300H and AVR X1400H specifically). "Dolby D" is displayed on the receivers. No audio with receivers without Atmos.

1st Gen AppleTV 4K: AppleTV 4K sends the audio out fine as Multi Channel to my Denon, but I haven't yet played with the Apple TV sound settings to try and get Dolby Digital out.

Chromecast w/Google TV: I get no audio. My GTVs are hooked directly up to Vizio TVs (no AVR).

1st Gen FireTV 4K: HDHR App crashes on ATSC 3.0 channels. The FireTV is connected directly to a NON Atmos capable AVR.

iPhone 13 Pro Max: Audio works fine

iPad 7th Gen, iPadOS 15: No Audio

Late 2012 Mac mini, Catalina macOS: No Audio

All systems have the latest HDHomeRun SW

hdmkv
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Re: AC-4 Audio?

Post by hdmkv »

@ferrellsl, thanks for your build w/AC-4 support.

ferrellsl
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Re: AC-4 Audio?

Post by ferrellsl »

hdmkv wrote: Fri Oct 01, 2021 1:09 pm @ferrellsl, thanks for your build w/AC-4 support.
You're welcome!

johnb7
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Re: AC-4 Audio?

Post by johnb7 »

I managed to get HDHR ATSC 3.0 working with Emby and VLC without modifying either of them using the ffmpeg AC4 branch. More details on how can be found in github. If you are comfortable with Docker containers, feel free to have a look at the complete solution that includes building ffmpeg from source. https://github.com/johnb-7/hdhr-ac4

This kind of solution could never be offered commercially (or even in binary form?), but as open source for personal use it should be OK. For those looking for audio perfection, this will not be good enough until ffmpeg support for AC4 gets better. As someone looking for the better quality of ATSC 3.0 signals in a tough spot for reception, this has been fantastic.

Cheers,

-John

sjm817
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Re: AC-4 Audio?

Post by sjm817 »

Looking for some help here with AC-4 audio. Been working on this for some time and cant figure it out. I have 3 Android TV devices. 2021 Sony X90J with built in ATSC 3.0 tuner, 2019 Sony without but in spec, shows AC-4 support, 2017 Nvidia Shield. For simplicity I will post about the 2021 Sony.

If I use the onboard tuner, the Sony shows the audio format as AC-4. That TV is connected to a Denon AVR. Denon shows the input signal as DD+ 5.1 so apparently, the Sony does the AC-4 to EAC3 transcode. Everything works fine. If I stream an ATSC 3.0 channel from the HDHR Flex, the Denon shows DD 5.1 input. Here is the issue. All of the Android TV devices show the DD 5.1 input, but there is only audio from L&R channels. The other channels are silent. For a test I tuned an ATSC 1.0 channel that only has 2 ch audio. The onboard tuner shows DD 2 CH on the Denon. The HDHR same channel shows DD 5.1, so looks like the HDHR always outputs 5.1 even if there is 2 ch content. What I cannot figure out is why the ATSC 3.0 channels from the HDHR are only 2 ch unless the broadcast is that which would be an extremely poor ATSC 3.0 implementation. I am in the Cincinnati OH market.

I believe there is supposed to be a HDHR update that supports AC-4 passthrough. The 2019 Sony should be able to decode that. Im hoping that solves the issue or at least gives me a better idea of what is going on.

Any ideas here?

emveepee
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Re: AC-4 Audio?

Post by emveepee »

I've got a new Android client apk written for NextPVR that I will be releasing soon that decodes AC-4 Live TV and recordings using a patched ffmpeg extension for AC-4. Of course it will also use h/w decoding if you are lucky. If someone wants to provide feedback PM me and I can provide a link to an apk that you can sideload

Note: This is NOT the app that is currently referenced on the NextPVR web site and is on the the Play Store. I expect it will only be available for sideloading

Martin
Last edited by emveepee on Mon Oct 11, 2021 10:21 am, edited 1 time in total.

sjm817
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Re: AC-4 Audio?

Post by sjm817 »

Hi Martin. I may be interested in this because of the issue I have posted just above your post. Question for you. Since the TV I want this for shows in spec as supporting AC-4, would that TV be able to be the device that does the decoding?

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