Transcoding Dolby Pro Logic to 5.1 surround

Hi all,

I recently got a soundbar that doesn't correctly decode/upmix stereo matrix surround sound like Dolby Pro Logic, and I was wondering if there might be a DIY way to take a DPL input and transcode it into something the soundbar will recognise (e.g. DTS 5.1 via optical, or maybe something through HDMI).

I am wondering about a couple of possible ways I might go about this:

1. Using hardware decoding
Seems like there are chips you can buy that decode this stuff. So perhaps I could build a device that feeds a stereo signal through the chips, and then outputs it as a true 5.1 surround signal.
2. Using a DSP
I have been looking at various Raspberry Pi solutions for DSP. I found a github that seems to have profiles for EqualizerAPO that purport to be able to at least somewhat properly upmix these signals (here). So I am thinking maybe I could achieve something similar using Like a HiFiBerry DAC+ Digi with a Raspberry Pi. It would need to be fairly low latency to meet my needs though.

I am not super experienced in this area, I can code and solder but I'm not much of an electrical engineer.. still I would be interested in attempting something like this as a kind of long term project/learning experience. If anyone here has any insight into whether something like this is practical/possible I would be very interested to hear about it! I understand there are some licensing issues around this stuff, but a lot of the discussions I have read online are really old so I am hoping there has been some progress I haven't uncovered in my search.

Any similar projects/recommended reading would also be welcome.

And, if someone has already solved this problem - well that would be awesome!