EqualizerAPO64-Hotkey

A fork of EqualizerAPO (double precision, 64-bit edition) with global hotkey support for the Editor added back to the UI.

What is this?

This project extends the equalizerAPO64 build (a double-precision, AVX-optimized 64-bit port of EqualizerAPO) with a feature that the original Editor lacked:

• Per-filter global hotkeys — assign a system-wide keyboard shortcut (e.g. Alt+X) to any filter to toggle its enabled state from any application, even when the Editor is in the background.

The feature was originally present in older EqualizerAPO releases but was removed at some point. This project restores it, with a clean implementation that works correctly under Qt 6.

Features (added by this fork)

• ✅ Global hotkey registration via Win32 RegisterHotKey API
• ✅ Per-filter shortcuts stored in the Windows registry (HKCU\Software\EqualizerAPO\Hotkeys)
• ✅ Works while Editor is in the background (uses a dedicated worker thread + GetMessage loop, bypassing Qt 6's event loop which does not forward WM_HOTKEY to native event filters)
• ✅ Persistent settings — hotkeys survive Editor restart
• ✅ Conflict detection — refuses to register a hotkey that is already in use

All upstream features are preserved:

• 64-bit double precision audio processing
• AVX2 / AVX-512 optimizations
• Compatible with the original EqualizerAPO filter configuration format

Differences from upstream equalizerAPO64

File	Change
Editor/helpers/HotkeyManager.h	New — hotkey manager + worker thread
Editor/helpers/HotkeyManager.cpp	New — registration, dispatch, persistence
Editor/FilterTable.h / .cpp	Owns the HotkeyManager, connects signals
Editor/guis/CommentFilterGUI.*	UI to assign a hotkey to a filter
Editor/Editor.pro	Lists the new files in the Qt project
version.h	Version bump to 1.4.2 (this fork)
Editor/build/build.bat	Adds nmake clean step to avoid stale .obj caching

Building

Prerequisites

• Windows 10/11 x64
• Visual Studio 2022 with C++ workload
• Qt 6.10+ (msvc2022_64 kit)
• All upstream dependencies — see upstream README for the full list and the LIBSNDFILE_INCLUDE, FFTW_INCLUDE, MUPARSERX_INCLUDE, TCLAP_ROOT env vars.

Steps

cd Editor\build
build.bat

The installer will be produced under Setup\EqualizerAPO-x64-1.4.2-Hotkey.exe.

Usage

1. Install the released installer (or build from source).
2. Open the Editor.
3. Right-click any filter in the filter chain → Set Hotkey (or use the UI control).
4. Press the desired key combination (e.g. Alt+X).
5. With the Editor running in the background, press your hotkey — the filter toggles.

Hotkeys are stored in the registry under HKCU\Software\EqualizerAPO\Hotkeys\<filterId>\keySequence.

Implementation notes

The hotkey feature has a non-obvious implementation detail: under Qt 6, the main event loop does not use the standard Win32 GetMessage API for message retrieval, so WM_HOTKEY messages posted by RegisterHotKey to the main thread's message queue are never dispatched to user code. This fork solves it by running a dedicated HotkeyWorker thread with a classic GetMessage loop. See HotkeyManager.cpp for the full details and the comments explaining the workaround.

A second pitfall — and one that cost several iterations during development — is that the HotkeyManager must not be a Qt child of FilterTable, because FilterTable::updateGuis() calls deleteLater() on all child objects. If HotkeyManager is a child, it gets destroyed and its worker thread is killed mid-flight, breaking all subsequent hotkey registrations. The fix is to pass nullptr as the parent in the HotkeyManager constructor.

License

This project is licensed under the GNU General Public License v2 (or later), the same as the upstream EqualizerAPO. See License.txt for the full text.

Attribution

• Original EqualizerAPO — © Jonas Thedering and contributors. https://sourceforge.net/projects/equalizerapo/
• Double-precision 64-bit port — https://github.com/TheFireKahuna/equalizerAPO64
• Hotkey restoration and Qt 6 compatibility work — this fork.

Contributing

Issues and pull requests are welcome. For major changes please open an issue first to discuss.

Project status

Stable. The hotkey feature has been tested with Alt+X-style combinations on Windows 10/11 x64 with Qt 6.10. The implementation deliberately avoids hooking into Qt's event filter chain because Qt 6 no longer reliably forwards WM_HOTKEY through that path.