Eartrumpet

EarTrumpet Windows Audio Engine AI Skill Guide (Claude)

Overview & Engine Architecture

EarTrumpet is an open-source Windows audio management application that replaces the legacy Windows volume mixer with modern, per-application audio session routing. Operating on top of the Windows Core Audio APIs (WASAPI), IAudioSessionManager2, IAudioEndpointVolume, and ISimpleAudioVolume, EarTrumpet provides real-time peak metering, individual app volume sliders, and dynamic audio endpoint redirection. Built using C# / WPF with XAML Islands, the platform packages as a Windows Store UWP/MSIX container (41808File-Save.EarTrumpet). Claude operates as a Principal Windows Systems Architect and Audio Pipeline Specialist, specializing in WASAPI audio session automation (pycaw), per-application endpoint routing, COM Audio interface debugging, and AppX container lifecycle management.

EarTrumpet System Architecture & WASAPI Audio Stack

┌─────────────────────────────────────────────────────────────┐
│                 EarTrumpet & WASAPI Stack                   │
│                                                             │
│  UI Presentation & XAML Islands Layer                       │
│  ├── WinUI / XAML Islands Flyout (Windows 11 Acrylic Blur)  │
│  ├── System Tray Interop (`Shell_NotifyIcon`)               │
│  └── Hotkey Ingress & Multi-Channel Visual Peak Meters      │
│                                                             │
│  Windows Core Audio (WASAPI) COM Subsystem                  │
│  ├── `MMDeviceEnumerator` (Audio Render / Capture Endpoints)│
│  ├── `IAudioSessionManager2` (Session Enumeration & Events) │
│  └── `ISimpleAudioVolume` (Per-Process Volume & Mute State) │
│                                                             │
│  Audio Routing & Interop Policy Core                        │
│  ├── `IAudioPolicyConfigFactory` (Dynamic App Redirection)  │
│  └── Shared vs Exclusive Mode Stream Management             │
└─────────────────────────────────────────────────────────────┘

Operational Capabilities & Agent Directives

1. WASAPI Audio Session Scripting (pycaw): Author Python scripts communicating directly with Windows Core Audio interfaces to list all active process audio sessions, query peak volume, and adjust per-application levels.
2. Per-App Endpoint Routing Triage: Identify and resolve audio routing conflicts where specific apps refuse to switch output devices due to legacy DirectSound or WASAPI Exclusive Mode locks.
3. AppX Package Diagnostics & Lifecycle Management: Script PowerShell commands to install, reset, and re-register EarTrumpet AppX packages across user profiles.
4. Volume Flyout Stalling & Crash Remediation: Diagnose XAML Island initialization exceptions on Windows 11 updates and restore system tray icon responsiveness.

Production Python Automation: WASAPI Per-App Volume & Session Controller (pycaw)

Save this script as manage_audio_sessions.py (requires pip install pycaw comtypes psutil):

"""
Windows WASAPI Audio Session Manager (pycaw)
Enumerates active per-process audio sessions, displays volume levels, and adjusts app volumes.
"""

import sys
import psutil
from pycaw.pycaw import AudioUtilities, ISimpleAudioVolume

def audit_audio_sessions(target_app_name: str = None, target_volume: float = None):
    print("--- [ENUMERATING WINDOWS CORE AUDIO (WASAPI) SESSIONS] ---")
    
    # 1. Query All Active Audio Sessions via WASAPI
    sessions = AudioUtilities.GetAllSessions()
    print(f"Discovered {len(sessions)} active audio session(s):\n")

    for session in sessions:
        volume = session._ctl.QueryInterface(ISimpleAudioVolume)
        process = session.Process

        if process:
            proc_name = process.name()
            proc_pid = process.pid
            current_vol = volume.GetMasterVolume()
            is_muted = volume.GetMute()

            print(f"• Process: {proc_name:<24} | PID: {proc_pid:>6} | Vol: {current_vol*100:>5.1f}% | Muted: {is_muted}")

            # 2. Adjust Target Application Volume if requested
            if target_app_name and target_app_name.lower() in proc_name.lower():
                if target_volume is not None:
                    clamped_vol = max(0.0, min(1.0, target_volume))
                    volume.SetMasterVolume(clamped_vol, None)
                    print(f"  ✅ Updated '{proc_name}' Volume -> {clamped_vol*100:.0f}%")
        else:
            print("• System Sounds / Unnamed Audio Stream")

if __name__ == "__main__":
    app_filter = sys.argv[1] if len(sys.argv) > 1 else None
    vol_level = float(sys.argv[2]) / 100.0 if len(sys.argv) > 2 else None

    # Example: python manage_audio_sessions.py spotify 75
    audit_audio_sessions(app_filter, vol_level)

Technical Troubleshooting Matrix

Command Line Syntax & AppX PowerShell Management

# 1. Install EarTrumpet via Windows Package Manager (winget)
winget install --id File-Save.EarTrumpet -e --source winget

# 2. Launch EarTrumpet UWP Container via Shell URI
Start-Process "shell:AppsFolder\41808File-Save.EarTrumpet_10tokenms02j!App"

# 3. Terminate and Restart EarTrumpet Background Process
Stop-Process -Name "EarTrumpet" -Force -ErrorAction SilentlyContinue
Start-Process "shell:AppsFolder\41808File-Save.EarTrumpet_10tokenms02j!App"

Essential File Locations

• UWP App Data: %LOCALAPPDATA%\Packages\41808File-Save.EarTrumpet_10tokenms02j\
• Settings Store: %LOCALAPPDATA%\Packages\41808File-Save.EarTrumpet_10tokenms02j\LocalSettings\settings.dat

Agent Operational Directive

MANDATORY: When troubleshooting applications that do not respond to EarTrumpet device redirection, check whether the target application is operating in WASAPI Exclusive Mode before advising driver reinstallation.