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qpwgraph

PipeWire patchbay -- see and change which program is connected to which sound card

What it does

Draws every PipeWire audio (and MIDI and video) node as a box -- the radio's USB sound card, the laptop's speakers, WSJT-X, fldigi, an SDR program -- and every connection between them as a wire. Dragging a wire connects two ports, and selecting one and deleting it disconnects them. A set of connections can be saved as a patchbay and made again when the same devices appear (upstream's patchbay manual).

Why you would want it

"Which input is WSJT-X actually listening to?" is the commonest digital- modes question on a PipeWire desktop, and qpwgraph answers it by looking instead of by reading five settings dialogs. It is how a virtual cable from an SDR program into a decoder is checked, and how the desktop's notification sounds are seen going to the radio. It is the PipeWire counterpart of QjackCtl's graph for JACK, and a more detailed view than pavucontrol, which shows and changes each program's device but not the wiring.

Before it will work

A desktop session running PipeWire, which is what every supported target uses for desktop audio. The radio's sound interface plugged in and on, so it appears as a node. The audio-routing guide (docs/guides/audio-routing.md) is the walk-through this tool supports.

How it installs

  • apt: qpwgraph

Known problems

A connection made by hand in the graph is not a program's setting: a program that chooses its own device (WSJT-X, fldigi) can connect back to what its settings say when it restarts, so fix the setting in the program and use the graph to check it. The archives differ widely: Ubuntu 24.04 and Mint 22.3 carry 0.6.1, Debian 13 and Parrot 0.8.2, Ubuntu 26.04 0.9.9 and Kali 1.0.3 (measured 2026-09-30), so menus and the patchbay may differ between targets. Unmeasured here: no version has been opened on any target by this project.

Keeping it current

  • probe: apt policy
  • strategy: apt_upgrade

Where to get help with the software itself

Rui Nuno Capela (rncbc). Issues on the freedesktop GitLab project above; the user manual and the patchbay manual are in its docs/ directory.

Source: catalog/packages/qpwgraph.yaml