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

Xerbo / aptdec

NOAA APT satellite imagery decoder

GNU General Public License v2.0

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How to Best "Pipe" Audio from Gqrx to aptdec? #25

Open AlexLandherr opened 10 months ago

AlexLandherr commented 10 months ago

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 commented 4 months ago

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.