ViPER4Windows

System-wide audio effects for Windows.

ViPER4Windows brings the ViPER audio processing engine to Windows. It installs as a Windows Audio Processing Object (APO) that hooks into the system audio pipeline and applies ViPER effects in real time to all audio output, with a modern Fluent UI front-end.

Features

Audio Effects

Effects are grouped by the page they live on in the UI:

• Output

  • Output Volume / Channel Pan / Master Limiter

• Equalizer

  • FIR Equalizer (10 / 15 / 25 / 31 bands) with importable/exportable EQ presets
  • Dynamic EQ (per-band threshold / attack / release)

• Tone

  • ViPER Bass (Natural / Pure Bass / Subwoofer) and Bass Mono
  • Psychoacoustic Bass Enhancement
  • ViPER Clarity (Natural / OZone / XHiFi)
  • Tube Simulator and AnalogX warmth
  • Spectrum Extension (VSE)

• Spatial

  • Field Surround (stereo widening, mid image, depth)
  • Differential Surround
  • Stereo Imager (3-band width control)
  • Headphone Surround+ (VHE) virtual surround for headphones
  • Reverberation with full room modeling
  • Auditory System Protection (CURe crossfeed)

• Dynamics

  • Playback Gain Control (AGC) and LUFS targeting
  • FET Compressor and Multiband Compressor (5-band)
  • Dynamic System headphone virtualization
  • Speaker Optimization (speaker-only)
  • ViPER-DDC device correction (.vdc profiles)
  • Convolver with WAV/IRS impulse responses

App Features

• Fluent design UI with a system-tray icon
• Per-device profiles with automatic switching on output change
• Cross-platform preset format shared with ViPER4Android and ViPER4Mac
• Preset, DDC, convolver kernel, EQ, and Dynamic System import/export
• Command-line interface (v4w-cli)
• Optional start-at-boot
• In-app driver status and per-endpoint APO registration

Requirements

• Windows 10 version 1809 or later (x64)
• Tested on Windows 10, theoretically supports Windows 11
• Visual Studio 2022 or later with C++ desktop workload (for building)
• Flutter SDK 3.11+ (for building the UI)
• Inno Setup 6 (for building the installer)

Installation

1. Download ViPER4Windows_Setup.exe from the Releases page and install it
2. Reboot — required for the audio driver to load
3. Open the app, go to the Driver Status page, and register the audio endpoints you want ViPER to process
4. A reboot may be required for registration to take effect
5. Tune your effects and enjoy

Building

Ensure MSBuild, flutter, and ISCC are on your PATH, then:

git clone --recursive https://github.com/likelikeslike/ViPER4Windows.git
cd ViPER4Windows
make installer

Build individual components:

make driver              # APO DLL only
make app                 # Flutter UI only
make installer           # Full build: driver + app + installer

Presets and Profiles

User data is stored in %APPDATA%\ViPER4Windows\. You can import and export:

• Full presets (JSON) capturing all effect settings at once
• DDC profiles (.vdc) for device-specific frequency correction
• Convolver kernels (WAV/IRS) for impulse response processing
• EQ presets and Dynamic System presets individually

Presets use the v2 grouped-JSON format (schemaVersion: 2) shared with ViPER4Android and ViPER4Mac — a preset saved on one platform loads identically on the others.

{
  "schemaVersion": 2,
  "name": "My Preset",
  "equalizer": { "enable": true, "bandCount": 10, "bands": [3.0, 2.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 2.0, 3.0] },
  "bass": { "enable": true, "mode": 0, "frequency": 55, "gain": 60 },
  "ddc": { "enable": false, "device": "" }
}

A preset holds a single unified effect state; it no longer stores separate headphone and speaker copies. State is applied to an output through the per-device profile system, and settings are saved automatically.

Command-line interface

ViPER4Windows installs a command-line tool, v4w-cli, alongside the app. Enable the "Add v4w-cli to PATH" option during installation to call it from any terminal.

v4w-cli controls the running app: commands are applied live, so loading a preset or toggling master updates both the UI and the audio in real time. If the app is not running, the command prints an error and exits non-zero.

v4w-cli preset list                 List saved presets
v4w-cli preset load <name>          Load a preset
v4w-cli preset save <name>          Save current settings as a preset
v4w-cli preset delete <name>        Delete a preset
v4w-cli preset rename <old> <new>   Rename a preset
v4w-cli preset import <path>        Import a preset .json file

v4w-cli master                      Show master on/off state
v4w-cli master on|off               Enable or disable all effects
v4w-cli master toggle               Flip the master state

v4w-cli device current              Show the current output device
v4w-cli device list                 List known devices
v4w-cli device show [id]            Show a device's id, name, and type
v4w-cli device delete <id>          Delete a device's saved settings

v4w-cli status                      Show master, driver, APO, and device status
v4w-cli help                        Show usage

Per-Device Profiles

Each audio output device keeps its own full effect profile. When you switch outputs, the app automatically loads the incoming device's profile, so your speakers and each pair of headphones remember their own tuning.

How a device is identified

The active output is detected from the Windows Core Audio API (the default render endpoint), and each device is keyed by its endpoint ID. The device's form factor (from its Windows properties) determines whether it is treated as headphone or speaker.

When profiles are saved and loaded

• On app background / close-to-tray / quit: the current settings are saved to the active device's profile.
• First time a device is seen: a profile is created automatically from the current settings.

Managing profiles

Open the Devices page (or use v4w-cli device ...) to manage saved profiles: view the current device, list known devices, or delete a device's saved settings.

Uninstall

Run the uninstaller from Add/Remove Programs. It removes all APO registrations, restores the original audio endpoint effect chains and DisableProtectedAudioDG value, deletes the start-at-boot shortcut, and cleans up registry entries.

The data folder in %APPDATA%\ViPER4Windows\ is not removed automatically; delete it manually if you want to clear your presets and profiles.

Credits

• ViPER4Android by Zhuhang and ViPER520
• ViPERDSP reverse engineering by Martmists, Iscle, and likelikeslike (ViPERDSP)