Windows 10 and Realtek Optical Output 5.1 DTS - How to Enable

Solution 1:

I've just spend whole Sunday solving this crap! But after all those hours I have working 5.1 audio on Windows 10 (1809) through optical S/PDIF on my ASRock X470 (Realtek ALC1220). And it's not just DTS pass through!

There are many VERY VERY LONG threads discussing this, with the most useful comment being this one.

The solution:

1. You need to download this patcher (alternative link) that will enable the missing features.
2. Download a driver that is still compatible with the patcher - in my case I've used version 2.82, the file name is "0009-64bit_Win7_Win8_Win81_Win10_R282.exe" (this is a two year old driver!!! I've tried to use the official one for my motherboard but the patcher didn't work).
3. Unzip the driver installer .exe file (using WinRAR for example) to access the contained files and patch "RltkAPO.dll" and "RltkAPO64.dll" in the "WIN64" directory (see "[Filename]" section in the patcher user interface).
4. Install the driver (run "Setup.exe" from the extracted driver) - here you might get a warning from Windows that the driver is not signed!
5. Reboot and finish configuration in the "Sound" window:
   a) on the tab "Enhancements" check "Disable all sound effects"
   b) on the tab "Advanced" select "Dolby Digital Live (5.1 Surround)" or "DTS Interactive (5.1 Surround)" - FINALLY!!!

If this feels like too much, here is the fixed installer (0009-64bit_Win7_Win8_Win81_Win10_R282). You still need to perform step 5 and execute the patcher - it needs to modify your Registry.

PS: Testing video file.

NOTE: The patcher gets some false-positive detection. But it doesn't require elevated rights to be executed and it's 4 years old. So I would say it's quite safe.