MPV downmix multichannel DTS to stereo

[bazil]

Hi all!
Very long time I try to fix problem with mpv on my computer.
I use Debian. Problem was with Jessie and now with Stretch.
When I try to open in mpv file with 5.1 DTS sound or 7.1 mpv always tell me [ao/alsa] Asked for 6 channels, got 2 - fallback to stereo.

For example:

mpv --audio-device=alsa/iec958:CARD=Juli,DEV=0 --alsa-ignore-chmap 00001.m2ts

Playing: 00001.m2ts

...

(+) Video --vid=1 (h264 1920x1080 23.976fps)
(+) Audio --aid=1 (dts 6ch 48000Hz)
Audio --aid=2 (ac3 6ch 48000Hz)
Audio --aid=3 (dts 6ch 48000Hz)
Audio --aid=4 (ac3 6ch 48000Hz)
Audio --aid=5 (dts 6ch 48000Hz)
Audio --aid=6 (ac3 6ch 48000Hz)
Subs --sid=1 (hdmv_pgs_subtitle)
Subs --sid=2 (hdmv_pgs_subtitle)
Subs --sid=3 (hdmv_pgs_subtitle)
Subs --sid=4 (hdmv_pgs_subtitle)
Subs --sid=5 (hdmv_pgs_subtitle)
Subs --sid=6 (hdmv_pgs_subtitle)
Subs --sid=7 (hdmv_pgs_subtitle)
Subs --sid=8 (hdmv_pgs_subtitle)
Subs --sid=9 (hdmv_pgs_subtitle)
Subs --sid=10 (hdmv_pgs_subtitle)
Subs --sid=11 (hdmv_pgs_subtitle)
Subs --sid=12 (hdmv_pgs_subtitle)
Subs --sid=13 (hdmv_pgs_subtitle)
Subs --sid=14 (hdmv_pgs_subtitle)
[ao/alsa] Asked for 6 channels, got 2 - fallback to stereo.
AO: [alsa] 48000Hz stereo 2ch s16
VO: [opengl] 1920x1080 yuv420p
AV: 00:00:01 / 01:56:10 (0%) A-V: -0.000

VLC work good and I always have DTS passthrough

I tryed to use many variants.
If I try to show to mpv how many speakers I have he show me another message

mpv --audio-device=alsa/iec958:CARD=Juli,DEV=0 --audio-channels=fl-fr-bl-br-fc-lfe --audio-spdif=dts-hd,ac3 00001.m2ts
Playing: 00001.m2ts
...
[ao/alsa] Asked for 8 channels, got 2 - fallback to stereo.
Passthrough format unsupported.
AO: [alsa] 48000Hz stereo 2ch s16
VO: [opengl] 1920x1080 yuv420p

Maybe anybody can show me the right way for fixing this problem?

Thanks to all!

[Hoser Rob]

I use Linux but it's Mint, not Debian, and I don't use mpv. I suspect you may have better luck on the debian forums.

However, I did find this bugzilla, and it doesn't look resolved ...

https://github.com/mpv-player/mpv/issues/1313