Shield Pro Audio

Help and support for HDHomeRun DVR and HDHomeRun software for Windows 10, Mac, Android, XBox, etc.
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MBrown2020
Posts: 9
Joined: Sat Mar 07, 2020 11:33 am

Shield Pro Audio

Post by MBrown2020 »

Just got a new Nvidia Shield Pro for use with the HDHomerun App (The best/recommended device). So far everything seems fine except that my receiver (Marantz AV8802a) is displaying DD+ 5.1 audio. The network streams are regular DD(AC3?) MPEG2 video, so why is the it transcoding to DD+. I want unaltered video and audio to be used. Any idea why? Any way the get original audio (DD)?

foxbat121
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Device ID: 131087C9, 13233B7C

Re: Shield Pro Audio

Post by foxbat121 »

The Shield is only capable of transcoding DD+ to DD (Turn on Dolby Processing), not the other way around. HDHomerun App is only capable of either bitstream or decode into 2-ch stereo. So, the chances are your TV channel is sending out DD+ or your receiver mis-identifies.

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EddieP
Posts: 232
Joined: Sat Jun 08, 2019 11:04 am

Re: Shield Pro Audio

Post by EddieP »

MBrown2020 wrote:
Sat Jun 06, 2020 4:20 pm
Just got a new Nvidia Shield Pro for use with the HDHomerun App (The best/recommended device). So far everything seems fine except that my receiver (Marantz AV8802a) is displaying DD+ 5.1 audio. The network streams are regular DD(AC3?) MPEG2 video, so why is the it transcoding to DD+. I want unaltered video and audio to be used. Any idea why? Any way the get original audio (DD)?
Make sure pass through Audio is enabled in settings of the HDHomeRun APP.

nickk
Silicondust
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Re: Shield Pro Audio

Post by nickk »

foxbat121 wrote:
Sun Jun 07, 2020 5:23 am
The Shield is only capable of transcoding DD+ to DD (Turn on Dolby Processing), not the other way around. HDHomerun App is only capable of either bitstream or decode into 2-ch stereo. So, the chances are your TV channel is sending out DD+ or your receiver mis-identifies.
This isn't correct.

1) The HDHomeRun app supports decoding to 5.1 PCM audio.
2) The HDHomeRun app supports encoding to AC3 if needed.

Note - if you are using coax/optical audio you need to use AC3 to get 5.1 due to bandwidth limitations of coax/optical. HDMI will do 5.1 audio in both AC3 and PCM formats.

One other special case - rare but some TV channels encode stereo content as the L and R channels of 5.1, other channels silent. A home theater system will normally up-convert stereo but in this situation the audio is encoded as 5.1 so you just get L and R without the expected up-conversion. The HDHomeRun app auto-detects this situation and outputs 2-channel audio so the home theater system can do its job and up-convert to use all the speakers.

MBrown2020
Posts: 9
Joined: Sat Mar 07, 2020 11:33 am

Re: Shield Pro Audio

Post by MBrown2020 »

I'm using HDMI (Shield->HDMI->Marantz->HDMI->LG C7 OLED). If I turn "Dolby Processing" to "Off" in the Shield's audio settings, my Marantz says regular DD. If I leave "Dolby Processing" to "On" the Marantz displays DD+. So I guess I'll leave it off. Will that be a problem for anything else?

foxbat121
Posts: 1781
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Device ID: 131087C9, 13233B7C

Re: Shield Pro Audio

Post by foxbat121 »

Dolby Processing on is meant to let Shield streaming apps to receive DD+ and output DD for compatibility with devices that can't handle DD+. The reason this is needed is that all Stream APPs, like Netflix, Prime Video etc., delivers either DD+ or 2-ch stereo. In order to receive 5.1 audio on an old device that doesn't support DD+, you need to turn this on. But it seems has some unintended consequences for regular DD.

If you already have DD+ capable receiver, you want to turn it off to avoid any transcoding.

nickk
Silicondust
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Re: Shield Pro Audio

Post by nickk »

One other situation of note - the HDHomeRun app will convert 5.0 audio to 5.1 audio as some FireTV models don't support 5.0 audio.

Nick

Timbo2
Posts: 51
Joined: Fri Jan 31, 2014 1:36 pm

Re: Shield Pro Audio

Post by Timbo2 »

nickk wrote:
Sun Jun 07, 2020 7:29 am
One other special case - rare but some TV channels encode stereo content as the L and R channels of 5.1, other channels silent. A home theater system will normally up-convert stereo but in this situation the audio is encoded as 5.1 so you just get L and R without the expected up-conversion. The HDHomeRun app auto-detects this situation and outputs 2-channel audio so the home theater system can do its job and up-convert to use all the speakers.
Nick is it possible to to stop this behavior? My 10 year old AVR has long pauses when the stream changes from 5.1 to 2.0. it means you can miss the beginning of a TV shows when coming from a block of commercials. It was never an issue with WMC, but it's annoying quirk of the HDHomeRun app.

I believe you have an option to force PCM, but my AVR doesn't do as good a job with the processing in PCM mode compared to actual DD/DD+.

mcewinter
Posts: 654
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Device ID: 131044D3, 103188F3
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Re: Shield Pro Audio

Post by mcewinter »

Timbo2 wrote:
Thu Jun 11, 2020 9:29 am
nickk wrote:
Sun Jun 07, 2020 7:29 am
One other special case - rare but some TV channels encode stereo content as the L and R channels of 5.1, other channels silent. A home theater system will normally up-convert stereo but in this situation the audio is encoded as 5.1 so you just get L and R without the expected up-conversion. The HDHomeRun app auto-detects this situation and outputs 2-channel audio so the home theater system can do its job and up-convert to use all the speakers.
Nick is it possible to to stop this behavior? My 10 year old AVR has long pauses when the stream changes from 5.1 to 2.0. it means you can miss the beginning of a TV shows when coming from a block of commercials. It was never an issue with WMC, but it's annoying quirk of the HDHomeRun app.

I believe you have an option to force PCM, but my AVR doesn't do as good a job with the processing in PCM mode compared to actual DD/DD+.
I have relatively current AVR that behaves the same way. Onkyo is a decent brand but if they all do this, it'll be my last Onkyo.

nickk
Silicondust
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Re: Shield Pro Audio

Post by nickk »

Timbo2 wrote:
Thu Jun 11, 2020 9:29 am
nickk wrote:
Sun Jun 07, 2020 7:29 am
One other special case - rare but some TV channels encode stereo content as the L and R channels of 5.1, other channels silent. A home theater system will normally up-convert stereo but in this situation the audio is encoded as 5.1 so you just get L and R without the expected up-conversion. The HDHomeRun app auto-detects this situation and outputs 2-channel audio so the home theater system can do its job and up-convert to use all the speakers.
Nick is it possible to to stop this behavior? My 10 year old AVR has long pauses when the stream changes from 5.1 to 2.0. it means you can miss the beginning of a TV shows when coming from a block of commercials. It was never an issue with WMC, but it's annoying quirk of the HDHomeRun app.
Can you please turn on "send diagnostic information" from within the HDHomeRun app (settings menu), reproduce the problem, then post back with the Device ID of your HDHomeRun.

This will enable me to check if the 5.1 to 2 ch switch is being done by the broadcaster (common) or by the HDHomeRun app fixing the stereo encoding on 5.1 problem some broadcasters do.

Nick

Timbo2
Posts: 51
Joined: Fri Jan 31, 2014 1:36 pm

Re: Shield Pro Audio

Post by Timbo2 »

nickk wrote:
Thu Jun 11, 2020 1:40 pm
Can you please turn on "send diagnostic information" from within the HDHomeRun app (settings menu), reproduce the problem, then post back with the Device ID of your HDHomeRun.

This will enable me to check if the 5.1 to 2 ch switch is being done by the broadcaster (common) or by the HDHomeRun app fixing the stereo encoding on 5.1 problem some broadcasters do.

Nick
Hi Nick,
We time shift almost all content can you tell from a recorded file or do you need it live? Assuming you log it when I'm playing back a recorded file I can definitely do as you've asked. Only issue right now is thanks to the virus I don't have any shows recorded. It may take me a few days to get a recording with the issue.

Thanks, Tim

Timbo2
Posts: 51
Joined: Fri Jan 31, 2014 1:36 pm

Re: Shield Pro Audio

Post by Timbo2 »

nickk wrote:
Thu Jun 11, 2020 1:40 pm
Can you please turn on "send diagnostic information" from within the HDHomeRun app (settings menu), reproduce the problem, then post back with the Device ID of your HDHomeRun.

This will enable me to check if the 5.1 to 2 ch switch is being done by the broadcaster (common) or by the HDHomeRun app fixing the stereo encoding on 5.1 problem some broadcasters do.

Nick
Hi Nick,

I spoke too soon! I actually had a recording! It's at the 16:00 to 17:00 mark. The commercial plays as simulated DD and the TV show is in DD.

Devices:
HDHomeRun DUAL 1010A24D
HDHomeRun DUAL 10146F83
HDHomeRun EXTEND 10547B76
HDHomeRun EXTEND 1054E466
HDHomeRun PRIME 1318B8DD
HDHomeRun SERVIO 15303B1E

I've also saved off the file - so I can send you a private link to that if you can't tell from what I just logged.

Thanks, Tim

nickk
Silicondust
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Joined: Tue Jan 13, 2004 9:39 am

Re: Shield Pro Audio

Post by nickk »

Diagnostic information came through - thanks.

The AC3 data from the broadcaster is sometimes 5.1 channel and sometimes 2 channel (not related to the HDHomeRun app). The HDHomeRun app is having to reconfigure the Android audio path each time the channel count in the broadcast changes.

nickk
Silicondust
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Joined: Tue Jan 13, 2004 9:39 am

Re: Shield Pro Audio

Post by nickk »

Thoughts that come to mind...

It would be interesting to see if you see the same problem with a different player that supports AC3 passthrough. The HDHomeRun app has to reconfigure the audio path and the home theater system has to switch modes so I am pretty sure it is going to experience the same problem.

Another easy test would be to use the HDHomeRun app on a Windows 10 PC to play the same recording - make sure it is operating in AC3 passthrough mode and see if you experience the same problem. Note however that even if it works it doesn't mean Android can do the same.

In theory we could up-convert the stereo audio from TV commercials to 5.1. That would avoid the mode switch completely.

Timbo2
Posts: 51
Joined: Fri Jan 31, 2014 1:36 pm

Re: Shield Pro Audio

Post by Timbo2 »

nickk wrote:
Thu Jun 11, 2020 7:12 pm
It would be interesting to see if you see the same problem with a different player that supports AC3 passthrough. The HDHomeRun app has to reconfigure the audio path and the home theater system has to switch modes so I am pretty sure it is going to experience the same problem.

Another easy test would be to use the HDHomeRun app on a Windows 10 PC to play the same recording - make sure it is operating in AC3 passthrough mode and see if you experience the same problem. Note however that even if it works it doesn't mean Android can do the same.

In theory we could up-convert the stereo audio from TV commercials to 5.1. That would avoid the mode switch completely.
Hi Nick,

Thanks for checking! I did actually what you asked when I downloaded the file. On the exact same home theater setup I have a Win 7 PC attached to another HDMI input that I use to run WMC. Using VLC and passthrough on the same file, the AVR passes the audio through with no muting or pauses in the audio. You can see where the stream changes from 5.1 to 2.0 on the AVR display, but there is no interruption in the sound. The issue would appear to be the way Android handles the sound. I seem to recall the WMC solution to this was to force the stream to stay 5.1.

Let me know if I can help further.

Thanks, Tim

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