PlaceboPlayer

A minimalist Android music player focused on audio quality for USB DACs.

Key Features

• Bit-perfect audio output - Direct USB DAC support with no resampling or mixing
• Gapless playback - Seamless transitions between tracks
• Aggressive buffering - Pre-loads songs into memory for instant playback
• Folder-based navigation - No library, just browse your files
• Privacy-first - No tracking, no analytics, no network communication
• AOSP compatible - Works on pure Android without Google services

Technical Highlights

• Min SDK: API 34 (Android 14.0+) for advanced AudioTrack API
• Architecture: MVVM with Jetpack Compose
• Playback: Media3 fork with BitPerfectAudioOutputProvider for USB DACs
• Media Session: Lock screen controls and notification integration
• Data Architecture: Dual database design (persistent settings + regenerable cache)
  • Persistent Database (userdata): Settings, playlists, playback history
  • Cache Database (cache storage): Metadata, cover art (cleared by Android when storage low)

Known issues

• Gapless playback doesn't work correctly

Planned features

• Use cache to speed up folder navigation - populate immediately from cache, progressively update as directory listing is updated
• A "stats for nerds" screen with detailed debug info. A detailed display of buffer usage, etc.
• Display an amplitude waveform instead of the seek bar, allow sliding it back and forth to seek ("waveform seekbar")

Quick Start

# Build app
./gradlew assembleDebug

# Start emulator with GUI, install the built apk and run it
./scripts/emulator.sh --gui

Available Scripts

• emulator.sh - Install APK and run app in emulator, starting the emulator if not already running.
  • --gui - Enable graphical interface
  • --install-apk <path> - Install specified APK instead of the default
• app_restart.sh - Kill, reinstall and restart the app on emulator
• app_logcat.sh - Stream logs from the app (use with timeout)
• app_play_intent.sh - Trigger playback via intent (for automated testing)

Automated Testing & Debugging

The app supports intent-based playback triggering for automated testing:

# Trigger playback with test files
./scripts/app_play_intent.sh

# View logs (use timeout to limit output)
timeout 10 ./scripts/app_logcat.sh

# Reinstall and restart app
./scripts/app_restart.sh

The app_play_intent.sh script demonstrates how to:

• Send a PLAY_AUDIO intent with a content:// URI
• Provide an optional queue of tracks
• Trigger playback programmatically without UI interaction

See CLAUDE.md for technical details.

Documentation

• CLAUDE.md - Technical documentation for developers and AI agents

License

GPLv2+