AAC 5.1 only plays sound through TV speakers, not surround system

[threnos 0]

Problem

• AAC 5.1 no longer plays sound through my surround system (it used to), but can still play through TV speakers (eww)

 

History

• My setup worked correctly for years with AAC 5.1 files direct playing to the surround system. In fact, AC3 file were problematic on this Roku stick when I first set up my media server a few years ago. So now I have thousands of files in my library that I have deliberately curated to use AAC.
• I assume something must have auto-updated, but I'm not sure if it was the Roku OS, the Emby app on Roku, or the EmbyServer.

 

Setup

• Official EmbyServer version 4.9.3.0, running as Docker on Unraid
• Roku Streaming Stick (Roku OS 15.2, app version Roku SG 4.1.59, latest available)
• Surround sound system connected via HDMI eARC

 

Things I've tried/ruled out

• Surround system hardware is fine — AC3 5.1 works perfectly and plays sounds on all speakers+sub; so does live TV through the Roku app
• Ensured Roku OS is using latest version
• Reinstalled Emby app on Roku to latest version
• Reinstalled official EmbyServer docker on unraid
• Confirmed Night Mode and Auto Leveling are both OFF
• Roku audio settings are NOT using"Auto" (the two settings are set to Dolby, and Custom > Dolby Digital Plus)
• Set "Convert Multi-Channel AAC" to YES in the Emby Roku app
• Deleted the device from Emby Server to forced re-registration, then power-cycled everythin

 

 What I assume is the root cause

• Client tells the server that it does not support AAC 5.1
• Setting "Convert Multi-Channel AAC" to YES in the Roku app has no effect on the reported device profile; the "authentication.db" capabilities JSON remains unchanged after the above. The Roku app is still reporting AAC as 2-channel-only, regardless of this setting.

Every time the Roku requests playback of an AAC 5.1 stream, the server logs show:

Profile: VideoAudioCodecProfile, DirectPlay=false. 
Reason=Roku SG.AudioChannels Condition: LessThanEqual. ConditionValue: 2. IsRequired: True.

And the resulting transcode URL contains `aac-audiochannels=2`, meaning the server is capping AAC to 2 channels. The device profile stored in authentication.db confirms the Roku app is reporting:

json{"Type":"VideoAudio","Conditions":[{"Condition":"LessThanEqual","Property":"AudioChannels","Value":"2","IsRequired":true}],"ApplyConditions":[],"Codec":"aac"}

 

Additional diagnostic info
Using a test file with 4 audio streams (AAC 5.1, AC3 5.1, AAC 2.0, AC3 2.0):

• AAC 5.1 → server transcodes it and plays fine on TV speakers, but no sound when switching to surround speakers
• AC3 5.1 → direct plays correctly on both TV and surround speakers
• AAC 2.0 → direct plays on TV speakers; no sound when switching to surround speakers
• AC3 2.0 → direct plays on TV speakers; no sound when switching to surround speakers

The transcode URL when AC3 is requested contains ac3-audiochannels=6, confirming the server knows the Roku can handle 6-channel AC3.

So as far as I can tell, the issue is purely the AAC channel limit being hardcoded to 2 in the reported profile, and I can't figure out how to change that.

 

Final Questions

• Is the "Convert Multi-Channel AAC" setting currently broken in the Roku app?
• Does it no longer update the capability profile sent to the server?
• If so, is there a server-side workaround that won't get overwritten every time the Roku reconnects?
• Should I just give up and begin the long process of re-encoding my entire library to AC3?
• Should I just buy a non-Roku option like NVIDIA shield?

Thank you in advance for any help.
 

[ebr 16429]

Hi. Please post the ffmpeg log from this playback.

24 minutes ago, threnos said:

when switching to surround speakers

Exactly what does this mean?  How do you do that?  What are these hooked up to?

[speechles 2083]

What do you have set for the options above on your Roku? Realize that "Auto" will only detect things correctly if your TV and AVR are turned on before the Roku is turned on. You might just need to restart the Roku (while TV and AVR are turned ON first) and let the auto-detect run again and it might work. The order the devices are turned on matters when Auto is used.

You can also choose to use Dolby for Preferred Streaming Format and then use Custom in Digital Output Format. Then on the Custom make sure Dolby is selected and DTS is not. If your audio equipment is capable of supporting DTS too. You can choose Auto for Streaming Format and on Custom choose both Dolby and enable DTS.

Certain Roku devices will convert 5.1 AAC into 2.0 AAC on the device. Other Roku devices do not support AAC 5.1 at all. The setting is to keep the devices which do not support AAC 5.1 from getting fed it. It also works on the devices which support AAC 5.1 to not allow the Roku to strip the extra channels and reduce it to AAC 2.0. You want that setting set to YES if you expect surround sound. AAC should be told to only send in 2 channel when that setting is set. This is what alerts the server it shouldn't go above that with AAC.

Edited May 2 by speechles

[threnos 0]

Thanks for the replies so far.

To clarify, "switching to surround speakers" means using the TV remote to select a different audio-output device. My soundbar/surround system is plugged in via a single HDMI eARC cable. The TV then sees two options for audio out: either the TV speakers, or the soundbar. It's easy to toggle back and forth between them when anything is playing. I usually don't have to, though, because I have previously always just left it on the soundbar 100% of the time.

Regarding the audio setting screenshots, I most recently tried with "Preferred streaming format" set to Dolby, and "Digital output format" set to "Custom", where I then select "Dolby Digital", where I then select "Dolby Digital Plus". Before this issue, I wasn't aware of these settings, and they were both on Auto, and I never had problems. Only from reading other posts did I become aware of them, but honestly in the 6+ hours I've spent on this problem before posting to the forum, I tried every possible combination of these settings (with a restart after each change) and nothing affected the issue.

I will try to post complete logs soon.

 

[threnos 0]

Logs attached.

I restarted the emby server to get some clean logs, so it should only have the 4 attempts I just made to play the single file with the 4 different audio tracks.

 

embyserver.txt

[ebr 16429]

2 hours ago, ebr said:

Please post the ffmpeg log from this playback.

 

[threnos 0]

Attached: ffmpeg logs from the same time period

ffmpeg-remux-e678ea2b-9f02-4d37-8e95-57996a2b2208_1.txt

[ebr 16429]

Hi.  Your ffmpeg log indicates we are sending DD (AC3).  It appears that then something in either the Roku or TV is deciding to send this to one output or another.  The Roku app does not control the actual audio output.

[Luke 42498]

Quote

Convert Multi-Channel AAC"

Did you try disabling this? it's worth re-evaluating from time to time to see if it might be handled differently following roku software updates. maybe it's not needed anymore.