I have a 5.1 Channel Onkyo Reciever connected to my Apple TV 4 and for some videos when the AppleTV is set to Best Quality output I will get the center channel out of the right speaker, if I set the AppleTV to 5.1 then that corrects the issue. The problem with this is that I lose the LPCM output by doing this.
I have uploaded the sample, any AC-3 or E-AC-3 is doing it.
Below is mediainfo of the E-AC-3
Format : E-AC-3
Format/Info : Enhanced Audio Coding 3
Codec ID : A_EAC3
Bit rate mode : Constant
Bit rate : 640 kb/s
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
And AC-3
Format : AC-3
Format/Info : Audio Coding 3
Codec ID : A_AC3
Bit rate mode : Constant
Bit rate : 384 kb/s
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
Below is the DTS-HD Working fine
Format : DTS
Format/Info : Digital Theater Systems
Format profile : MA / ES Matrix / Core
Codec ID : A_DTS
Bit rate mode : Variable / Constant / Constant
Bit rate : 3 630 kb/s / 1 509 kb/s / 1 509 kb/s
Channel(s) : 8 channels / 7 channels / 6 channels
Channel positions : Front: L C R, Side: L R, Back: L R, LFE / Front: L C R, Side: L R, Back: C, LFE / Front: L C R, Side: L R, LFE
Not sure if there are any test files out there I can use that may help.
EDIT: I just tested with MrMC and it will also do it if it is doing the decoding and I have passthrough disabled. If the AC-3 is passed through then it’s fine.
EDIT 2: I just tested passthrough mode in infuse with best quality on appletv and the audio comes through as PCM, problem is the same.
AppleTV on Best Available, Infuse on Auto or Passthrough
Speaker Heard on / Speaker On Screen
Front Left / Front Left
Front Right / Center
Subwoofer / Front Right
Left Surround / Right Surround
Left Surround / Right Rear Surround
Center / Left Rear Surround
Center / Left Surround
Subwoofer / LFE
With 5.1 Surround Setting on AppleTV, Infuse on Auto or Passthrough
Speaker Heard on / Speaker On Screen
Left / Left
Center / Center
Right / Right
Right Surround / Right Surround
Right Surround / Right Rear Surround
Left Surround / Left Surround
Left Surround / Left Rear Surround
Subwoofer / LFE
Edit: Considering MrMC gets the channels wrong as well I dug up my cubox-i running libreelec and tested kodi on its platform, everything mapped correctly on passthrough and built in decoding.
I just tested the 7.1 TrueHD test file, the 7.1 DTS-MA, a 5.1 AC3 test file. They all played properly on the correct speaker for me with Best Quality on the ATV4K and Auto for Infuse.