Denon Remote

A Qt 6 desktop remote control for Denon and Marantz network receivers. Developed against an AVR-X1400H.

How it works

The receiver announces every change on its own control port. This application keeps one connection open and treats it as the event source, so turning the front panel knob, pressing the infrared remote or changing the volume from the HEOS app all move the slider in the window. Nothing is polled, and no value in the interface is ever a guess about what the receiver did with a command.

The input list is read from the receiver too, under the names its owner gave the inputs and without the ones hidden in its setup. Older receivers that don't report it over the control connection are asked for their web page instead.

Features

• Main zone, zone 2 and zone 3: power, volume in decibels, mute, input
• Surround modes, Quick Select presets under their names on the receiver
• Bass, treble and subwoofer trim, dynamic range, Restorer, ECO, sleep timer
• Cursor control for the on-screen setup menu
• Receiver discovery on the local network, or a typed address
• Tray icon for power and mute; the mouse wheel over it changes the volume by half a decibel per notch
• Optional closing to the tray
• Automatic reconnection

Controls for things a model doesn't have, such as zone 3 or a fifth Quick Select slot, are not shown.

Building

Needs Qt 6.4 or newer and KStatusNotifierItem from KDE Frameworks 6.

sudo apt install build-essential cmake qt6-base-dev qt6-svg-plugins \
    libkf6statusnotifieritem-dev
cmake -S . -B build -DCMAKE_BUILD_TYPE=RelWithDebInfo
cmake --build build -j$(nproc)
ctest --test-dir build
./build/denon-remote

Debian package

sudo apt install debhelper devscripts
dpkg-buildpackage -us -uc -b
sudo apt install ../denon-remote_*_amd64.deb

Release packages are built with scripts/build-deb-trixie.sh in a Debian 13.0 container, so they install on every Debian 13 release and on Ubuntu 26.04.

Protocol notes

Commands are plain text terminated with a carriage return on TCP port 23. The parts this application relies on:

Command	Meaning
PWON / PWSTANDBY	Main power
MV45 / MV455	Volume; three digits mean a half step. 80 is 0 dB
MVMAX 98	Ceiling configured on the receiver
MUON / MUOFF	Mute
SISAT/CBL	Input select
MSDOLBY SURROUND	Surround mode
MSQUICK1	Recall Quick Select preset
PSBAS 50	Bass, centred on 50
PSTONE CTRL ON	Tone control, without which bass and treble are ignored
Z2ON, Z240, Z2MUON, Z2SOURCE	Zone 2 power, volume, mute, input; Z3… likewise for zone 3
SSFUN ?	Input labels configured on the receiver
SSSOD ?	Which inputs are enabled
SSQSNZMA ?	Quick Select names (and how many slots)

Receivers that do not answer SSFUN ? are asked over HTTP on port 80 instead: /goform/formMainZone_MainZoneXml.xml?ZoneName=ZONE1 first, then /goform/formMainZone_MainZoneXmlStatus.xml. Both carry three parallel lists, InputFuncList, RenameSource and SourceDelete. An AVR-X1400H, for one, refuses both pages with 403.

Queries append ?; parameters under PS need a space first, as in PSBAS ?. The receiver drops commands sent back to back, so they are paced roughly 80 ms apart.

A command the receiver won't accept gets no reply at all. Bass and treble are ignored while tone control is off, subwoofer trim while PSSWL reports OFF, so those controls stay disabled until then. When adding a control, check on the hardware that the command is echoed back.

Apart from the state queries after connecting, nothing is sent unasked: a periodic query would keep the receiver out of auto-standby. A dead link is detected with TCP keepalive.

The application holds its control connection while it runs, also when closed to the tray. Quit it if another controller needs the port.

Layout

File	Role
src/AvrConnection.*	Connection, reconnection, command pacing, line framing
src/AvrState.*	Parses the event stream into mirrored state
src/Discovery.*	SSDP search, confirmed by Deviceinfo.xml or the UPnP description
src/WebCatalogue.*	Input list from the web page, for receivers without SSFUN
src/ZonePanel.*	Controls for one zone; used for all three
src/SoundPanel.*	Surround modes, tone, standing options
src/ConnectDialog.*	Receiver picker
src/MainWindow.*	Tabs, menus, tray icon, settings

tests/ holds the unit tests; the pages they parse are captures from real receivers (tests/data/NOTICE).

legacy/denon_control.py is the single-window GTK 3 script this application replaced. It is kept for reference only and is not built or packaged.

License

GPL-2.0-or-later; see LICENSE.