Mimmicking Kodi's 'Best Match' Audio Output Functionality?

[nmkaufman 49]

There are more and more movies appearing using multi-channel AAC rather than traditional multi-channel audio formats.

 

Kodi has the ability (when using WASAPI drivers) to set the audio channels & sampling rate to match the media I'm currently watching.

 

Is there a way to mimic this functionality with Emby Theater?

 

I noticed the ability to use 'dedicated' audio mode, and set the audio channels to 'Auto' but no source matching seems to be taking place.

 

Ideally, I'd like to leave my audio settings in 2.0 channel mode (to take advantage of Dolby Pro-Logic) but set the channels appropriately when necessary.

 

I honestly care much less about changing the sampling rate.

 

Thanks in advance.

Edited November 21, 2019 by nmkaufman

[Luke 36991]

@ some of this could probably be done with mpv.conf, right?

[Guest asrequested]

You're going to need to explain what exactly you mean. The way you've written that, it sounds like you want to resample what you're listening to, to what you're listening to. Which makes no sense.

[Guest asrequested]

So downmix everything? This doesn't make sense.

[Guest asrequested]

I think you probably just want to transcode the AAC audio to AC3, right?

[nmkaufman 49]

I want to set the audio output to my receiver to match the sampling rate / # channels of the media I'm currently watching.

 

There are new 'computer only' multichannel formats being used, that can't be bitstreamed to the receiver like AC3 or DTS can.

[Guest asrequested]

I want to set the audio output to my receiver to match the sampling rate / # channels of the media I'm currently watching.

 

There are new 'computer only' multichannel formats being used, that can't be bitstreamed to the receiver like AC3 or DTS can.

That doesn't make sense.

 

Just read this and see if this is more like what you want.

 

https://emby.media/community/index.php?/topic/63366-aac-audio-passthroufh/?hl=af

[nmkaufman 49]

It's the 'change display refresh rate to match video' option, but for audio.

[Guest asrequested]

It's the 'change display refresh rate to match video' option, but for audio.

No sense, whatsoever.

[nmkaufman 49]

I can't tell if you're being serious, or just having a bad day and giving me a hard time.

 

If I'm watching a movie with a 2 channel 48KHz soundtrack, I'd like the audio to my receiver to be set to 2-channels, 48KHz.

 

If I'm listening to 2 Channel, 44.1KHz music, I'd like the audio to my receiver to be set to 44.1KHz 2-channel.

 

If I'm watching a movie with a 5-channel, 48KHz AAC-Multichannel soundtrack, I want the output to my receiver to be set to 5-channel, 48KHz.

 

Having to transcode everything into AC3 is not a better solution.

 

AC3 is lossy, mutli-channel PCM from my HDMI to the receiver is not.

[Luke 36991]

But out of the box that's exactly what we do. 

[nmkaufman 49]

Maybe I need to upgrade my drivers or something, then.

 

All of the pass-through multi-channel formats are working correctly, but multi-channel AAC is being sent to my receiver in stereo.

[Luke 36991]

Make sure to configure the number of speaker channels in the app. And yes, certainly latest drivers should be step one.

[nmkaufman 49]

Thank you, I will try again when I get home.

 

I think what I'm describing might actually be confusing, though, too.

 

It's not about how Emby / Kodi handle stereo or surround sound content, it's about actually changing the output of the sound card to match.

 

That's why I thought the comparison with the 'change display refresh rate to match video content' analogy was appropriate.

 

If I send stereo content to my receiver while the output of my computer is configured to 5.1 or 7.1, the receiver's own surround processing (dolby pro logic) is disabled, and it plays only through the front speakers. That's the only reason any of this is important.

 

I will try when I get home, though, and see if it works as expected.

Edited November 21, 2019 by nmkaufman

[Guest asrequested]

Ok, so we're only talking about AAC audio being decoded directly without downmixing. This is a default. But because it's Windows, the Windows audio configuration needs to be set correctly to correlate with the audio channels of your system. Theater is going to directly decode the audio to PCM, so it's recommended that you set the channels correctly in Theater, and the Windows audio MUST be configured the same way. And transcoding AAC to AC3 won't be lossy, as you can choose what bitrate to output. I have mine set to 640Kb/s. And then you have true Dolby surround and not Pro Logic. With the added bonus of not relying on the Windows audio configuration, as it's bitstreamed.

Edited November 21, 2019 by Doofus

[nmkaufman 49]

I'll definitely play around with it this evening.

 

Thanks for the help.

[Guest asrequested]

I strongly suggest using the AC3 encoding with an auto-profile. It's going to give you the most satisfactory output. Pro Logic really isn't very good. As for compression, I don't think I have an AAC audio track above 320Kb/s. The most common AC3 bitrate is 384Kb/s. Also, the AAC audio is usually transcoded from an AC3 track, and is compressed further. If your receiver supports it, just set the encode bitrate to 640Kb/s, and you'll never look back.

Edited November 21, 2019 by Doofus

[nmkaufman 49]

So, interesting development.

 

I found an audio driver for my graphics card that adds Dolby Home Theater v4.

 

I now have surround sound processing baked right into the system, and can leave the output to my receiver on 5.1 at all times.

 

5.1 content gets passed through. Stereo content gets expanded to 5.1, with a center channel and everything. Absolutely beautiful.

 

But it doesn't work correctly in Emby Theater 3.0.0.10, (or Google Chrome if that gives any hints what the problem might be.)

 

It works in the Windows Store version, but 3.0.0.10 seems to bypass the Dolby Processing. Like it's using exclusive audio mode whether I tell it to or not.

 

I tried turning exclusive mode on and off, manually setting both auto and different numbers of channels. There's definitely something different happening with the audio in 3.0.0.10 vs the store app.

 

I'm not marking this thread un-answered, because I'm hoping it has something to do with the problems being reported in the other 3.0.0.10 audio thread.

Edited November 27, 2019 by nmkaufman

[Luke 36991]

It's two different video players between the two editions of the app so they won't be exactly the same.

[Guest asrequested]

Did you disable bitstreaming and remove the ac3enc command? If you want your audio driver to handle this, you'll need a straight decode, so Windows audio gets involved. If that doesn't work, post the corresponding mpv log.

[nmkaufman 49]

All my bitstream pass-thru options are disabled, and I never got around to trying the ac3enc stuff.

 

I just learned electon is based on Chromium, so I think it's no coincidence that chrome and Emby both behave the same way.

 

Finding a fix for one will probably solve both.

[Luke 36991]

Well browsers can't do any bitstreaming. Electron is only used for the UI, mpv is the video player.

[Guest asrequested]

The log will show what's happening.

[nmkaufman 49]

Sorry, I'm not home right now.

 

I'll tinker with it over the weekend, and if I'm still not having any luck I'll post logs on Monday.

 

Thanks again.

Edited November 27, 2019 by nmkaufman

[nmkaufman 49]

So I figured out it's because mpv uses WASAPI audio drivers in Windows, which by it's very nature bypasses all processing on the computer.

 

Whatever video player is used in the Windows Store version must use Directaudio.

 

The good news is that since mpv is using WASAPI, my original goal of having the number of channels / sampling rate set to match the content I'm watching should be possible.

 

Turns out, the trick was manually setting the flags:

 

--audio-channels=auto

--ao=wasapi

--audio-exclusive=yes

 

So either the 'auto' setting, or 'exclusive' setting inside ET must not be working correctly.