Question Decoding S/PDIF 5.1 from 2.0 source optical input?

[acrivec]

Hi,
My mi-box can output 5.1 surround sound through optical SPDIF output and my Soundblaster AE-9 has optical-in port.
I am able to use it as 2.0 source without problems, but when using 5.1 the sound is compressed, and this card does not have SPDIF decoding.
Is there any software available on Windows to decode SPDIF signal? I'm using Voicemeeter and the input is on ASIO mode, so it's digital signal should not be distorted.
I've been trying for some hours with ChatGPT but so far I'm failing. I know there's Linux SPDIF decoder but WSL does not use PulseAudio, which it relies on.

I'm trying to get 5.1 sound so I can watch netflix/hbo/amazon prime on 4k with surround sound without having to buy a HDMI sound splitter and manually connecting my speakers to the tv box/stick...
I believe it should be possible :|

 

[helpstar]

spdif optical has not the bandwitdh to get the signal uncompressed in 5.1
only 2.0

google:
optical spdif bandbwidth raw 5.1

how does your setup look like ?
mi-box -> hdmi in TV
and
mi-box -> spdif soundblaster?

 

[acrivec]

spdif optical has not the bandwitdh to get the signal uncompressed in 5.1
only 2.0

I know this, this thread does not state I need uncompressed 5.1 sound. This thread states that I need to decode it.

how does your setup look like ?
mi-box -> hdmi in TV
and
mi-box -> spdif soundblaster?

There's no TV.
mi-box is plugged into my monitor and it's optical is plugged into my PC's sound card optical in.