I am piping audio from my MacBook into my Raspberry Pi 3B.
MacBook -> Headphone output of USB soundcard -> TRRS cable -> RasberryPi jack input
I am then running it through a DSP algorithm which should decode the signal perfectly.
However, on my setup it is failing to decode the signal.
A couple of my teammates have it working (but sporadically). [EDIT: Turns out their setup is different, see answer].
Is there anything I need to take into account here?
Do I need to insert some resistor/capacitor circuitry?