libbluos_ssc.so is an MQA decoder library extracted from the firmware of a Bluesound MQA-capable DAC. You must source this library and the keys extracted from this library yourself.
The aforementioned library is an ARM library, for ARMv7 devices. Integrating this with an amd64 system is a pain, as to use the library, you have to create an ARMv7 executable that calls libbluos_ssc.so using dlopen, but such an executable can only run within a QEMU binary translation environment, making integration with the rest of a system with a different architecture very difficult.
This project uses shared memory IPC to communicate between a wrapper executable that uses dlopen and calls libbluos_ssc.so functions within a binary translation environment and a regular amd64 (or whatever else you want that supports QEMU binary translation) environment. Doing this allows us to be able to easily send FLAC binary "chunks" to the ARM environment for processing, one at a time, which will allow for real-time MQA audio playback from any userspace amd64 program by simply invoking this library.
Consult samples/sndfile_portaudio.c for sample usage of this library.