MPV not reading correct channel order from audio stream

[flippyfingw 0]

Was playing a media file in Emby Theater and could only hear background audio from my headphones, played the file (.mkv) with Windows media player (k lite codec pack with LAV package) and the audio came through fine. The specific audio track I'm having problem with has 5 channels and it seems the LAV package recognizes the correct order and downmixes the audio to stereo, while libmpv fails to do so. Tried with the standalone mpv player, to same effect (wrong channels playing). Emby theater uses libmpv with directplay on my hardware (GTX 1070, R5 2600, Windows 10 1809x64, latest nvidia drivers). Extracted the audio file which plays incorrectly on windows media player (media foundation), groove music, mpv player but plays correctly on VLC.
 
VLC can also play the file video file with correct channels and so can emby webapp on firefox, with audio directplay.
 
I'm attaching the file (.mka) here but the upload always gets stuck in a weird state I'm not allowed to upload .mka so also linking to firefox send, with maximum 20 downloads possible (limitation of firefox send). https://send.firefox.com/download/458e0ae409/#_gvUCf9gUQ2SVESQpNUroQ

Edited February 26, 2019 by flippyfingw

[Guest asrequested]

Put it in a zip file

[flippyfingw 0]

Thanks, didn't know if that would be called circumventing the rules or something. Uploaded now with this reply

01.zip

[Guest asrequested]

I'll test it, later. How do you have your audio configured in Theater? A screenshot would be helpful.

[Guest asrequested]

Just a quick test in mpv, results in stereo.

[   0.683][v][ao/wasapi] Disabling multichannel output.
[   0.683][v][ao/wasapi] Channel layouts:
[   0.683][v][ao/wasapi]  - stereo
[   0.683][v][ao/wasapi]  - 5.1
[   0.683][v][ao/wasapi]  - 7.1
[   0.683][v][ao/wasapi]  - 4.0
[   0.683][v][ao/wasapi]  - quad
[   0.683][v][ao/wasapi]  - 5.1(side)
[   0.683][v][ao/wasapi]  - 7.1(wide)
[   0.683][v][ao/wasapi] result: stereo
[   0.683][v][ao/wasapi] Accepted as stereo s32 @ 48000hz -> stereo s32 (32/24 bits) @ 48000hz (exclusive)

[   0.700][d][ao/wasapi] Init wasapi done
[   0.700][v][ao/wasapi] device buffer: 480 samples.
[   0.700][v][ao/wasapi] using soft-buffer of 9600 samples.
[   0.700][i][cplayer] AO: [wasapi] 48000Hz stereo 2ch s32
[   0.700][v][cplayer] AO: Description: Windows WASAPI audio output (event mode)
[   0.700][d][osc] osc_init 
[   0.700][v][autoconvert] inserting resampler
[   0.700][v][swresample] format change, reinitializing resampler
[   0.700][v][swresample] 48000Hz 5.0 floatp -> 48000Hz stereo s32
[   0.700][v][swresample] Remix: 5.0 -> stereo
[   0.701][v][af] [out] 48000Hz stereo 2ch s32

I need to know how you've configured Theater's audio, to be able try and figure out what's happening.

Edited February 27, 2019 by Doofus

[flippyfingw 0]

My speaker layout was set to auto, which had gave me those issues, changed to stereo and everything works fine now. Adding screenshots anyway. Might be an issue on my end with audio device configuration. Thanks for the help :-)

[Luke 42085]

Yea mpv docs actually suggest to always explicitly set the speaker layout rather than leaving it on auto.