Apple TV 5.1 Audio issues

[r0bot]

Hello @@corey,
Trying to determine the cause of this issue i am having were some 5.1 audio files will not play 5.1 audio and instead are converting to stereo. This is occurring with Direct Play files. Logs and Media Info for the two files attached.


With the file where 5.1 did not work it was "AAC LC", file when played created no FFMPEG log
With the file where 5.1 did work it was "AC-3"

Audio is playing through an Onkyo HT-R380, Apple TV connected via HDMI.
Apply TV is a 3rd Generation device on the latest OS version.
Emby application is the latest version.

Thanks,
r0BOT

embyserver_not_working.txt

embyserver_working.txt

ffmpeg-directstream-working.txt

Edited May 29, 2020 by r0bot

[r0bot]

I am out of my depth of knowledge here but I think the issue may be that the Apple TV can natively play the AAC audio but the receiver cannot, is this possibly the option? I am having a hard time finding support documentation on the receiver to confirm this. And if this is the case is there a way to force Emby to transcode AAC to AC-3?

[corey]

I am out of my depth of knowledge here but I think the issue may be that the Apple TV can natively play the AAC audio but the receiver cannot, is this possibly the option? I am having a hard time finding support documentation on the receiver to confirm this. And if this is the case is there a way to force Emby to transcode AAC to AC-3?

I don't have an exact answer for you here (and I don't think I have any equivalent media to test either) but the transcoding profiles are based on what the device supports, not what it may be sending audio data too (like your receiver). @@Luke may have some thoughts though.

[ebr]

Hi.  I do not believe the Apple TV supports multi-channel AAC.  Many devices don't.

 

If you set the Apple TV device to output Dolby Digital, doesn't that convert it for you?

[r0bot]

ebr,

   The Apple TV is set to Output Dolby Digital in the Setup of the Apple TV, it is the only option but Stereo. It does appear however to support AAC based on this (https://support.apple.com/kb/sp648?locale=en_US). The Emby program thinks it supports it I would guess based on the fact it doesn't trans-code it.

[ebr]

It "supports" AAC but that doesn't mean it can output 5.1 AAC.  I think it probably does a mix down and sends stereo to your receiver.  That is what most of these types of devices do with that particular audio.

[r0bot]

ebr,

    So is there a way I can change the configuration of Emby to always convert AAC to AC-3 for my Apple TV Devices?

[ebr]

Not at this time but its possible for the future.

 

Thanks.

[r0bot]

Thanks EBR. It would be nice to be able to set these types of options since the automatic configuration choice of Emby to send the Apple TV AAC even though it down converts it seems wrong in my opinion. Even if this is though advanced INI/Config files it would be good to have,

[teknokracy]

I am having the same problem, however it did not happen before I updated Emby. I do not run the server that I am on, but I have asked the owner to check in to it.

 

I was watching a TV series in 5.1 and then after the app updated the same series would force down mix to stereo. Nothing else in the AV setup changed. I can determine that this is not related to the AppleTV's ability to play the audio portion of the file

[sfatula]

Hi. I do not believe the Apple TV supports multi-channel AAC. Many devices don't.

 

If you set the Apple TV device to output Dolby Digital, doesn't that convert it for you?

In January, I tested AAC 7.1 with Emby and native player and it played fine as 7.1. I have a post about this. Emby did not convert the audio. This was in mp4 container. Have not tested on newer version Emby.

 

https://emby.media/community/index.php?/topic/81252-testing-14402/page-4&do=findComment&comment=829695

 

At the time, I was testing lossless audio formats to decide what to put in new encoded movies. While mine was 7.1 aac, and op is 5.1, I would expect 5.1 would have played also.

Edited June 4, 2020 by sfatula

[vdatanet]

DTS 5.1 is converted to AAC 5.1, which is not compatible with Apple TV.

[vdatanet]

On 5/29/2020 at 1:58 PM, corey said:

I don't have an exact answer for you here (and I don't think I have any equivalent media to test either) but the transcoding profiles are based on what the device supports, not what it may be sending audio data too (like your receiver). @@Luke may have some thoughts though.

@Luke Apple TV transcoding profiles should be modified. Apple TV does not support AAC 5.1, DTS 5.1 audio is converted to AAC 5.1 instead of AC3 5.1