How to Best "Pipe" Audio from Gqrx to aptdec?

[AlexLandherr]

Hi, I have this project idea:
https://forums.raspberrypi.com/viewtopic.php?t=358687

on how to get live decoding working on a Raspberry Pi 4 or Raspberry Pi 5.

My question is how would I "pipe" the audio from Gqrx to aptdec on Raspberry Pi OS?

[Xerbo]

APT is a very simple protocol, GPS and doppler tracking are completely unnecessary.

This is very easily doable with aptdec v2 and rtl_fm, see the README for a basic example. Should also be doable with the master branch with something like:

mkfifo /tmp/aptaudio
aptdec -r /tmp/aptaudio
rtl_fm -f 137.1M -g 40 -s 40k | sox -t raw -r 40k -e signed-integer -b 16 - -t wav /tmp/aptaudio

If you have to use GQRX this is best done with the UDP audio function.