Dolby Digital AC3 or DTS decoder with SPDIF and optical inputs that can output surround sound to analog 5.1
This is hybrid Analog - Digital SoC running Linux with Dolby Digital AC3 / DTS Decoder.
There's no bass management so DTS/AC3 tracks have only LFE (no other channels mixed)
Dolby Pro Logic is in Music Mode, LFE is lowpass filtered from stereo source. CS4344 alternative (24-Bit, 192 kHz Stereo D/A Converter) https://statics.cirrus.com/pubs/proDatasheet/CS4344-45-48_F2.pdf