rmpd

rmpd is a modern, high-performance, memory-safe music server written in pure Rust. It aims for 100% compatibility with the Music Player Daemon (MPD) protocol while providing first-class extensibility through a plugin architecture.

Features

• 🎵 MPD Protocol Compatible - Works with existing MPD clients (ncmpcpp, mpc, Cantata)
• 🦀 Pure Rust - Memory-safe, fast, and reliable
• 🔌 Extensible - Plugin system for decoders, outputs, and inputs
• 🎧 High-Quality Audio - DSD support, ReplayGain, gapless playback, crossfade
• 🎼 Format Support - FLAC, MP3, Ogg Vorbis, WAV, AAC, DSD (DoP and native)
• 🏠 Multi-Room Ready - Snapcast integration for synchronized playback
• 📱 Multi-Protocol - MPD and OpenSubsonic support (planned)
• ⚡ Efficient - Runs on everything from Raspberry Pi to high-end servers

Architecture

rmpd/
├── rmpd/               # Main binary
├── rmpd-core/          # Core types and traits
├── rmpd-protocol/      # MPD protocol implementation
├── rmpd-player/        # Audio playback engine
├── rmpd-library/       # Music library/database
├── rmpd-plugin/        # Plugin system
└── rmpd-stream/        # Streaming support

Quick Start

Prerequisites

System dependencies:

# Ubuntu/Debian
sudo apt-get install libasound2-dev pkg-config

# macOS
brew install pkg-config

Build

cargo build --release

Run

./target/release/rmpd --bind 127.0.0.1 --port 6600 --music-dir ~/Music

Test with mpc

# Check status
mpc status

# Update library
mpc update

# Add and play music
mpc add /
mpc play

Configuration

Create ~/.config/rmpd/rmpd.toml:

[general]
music_directory = "~/Music"
playlist_directory = "~/.config/rmpd/playlists"
db_file = "~/.config/rmpd/database.db"
log_level = "info"

[network]
bind_address = "127.0.0.1"
port = 6600

[audio]
default_output = "alsa"
gapless = true
replay_gain = "auto"
buffer_time = 500

[[output]]
name = "ALSA Output"
type = "alsa"
enabled = true
device = "default"

[[output]]
name = "Snapcast Output"
type = "snapcast"
enabled = false
fifo_path = "/tmp/snapfifo"

See rmpd.toml for a complete configuration example.

Audio Format Support

Supported Formats

• Lossless: FLAC, WAV, ALAC, APE, WavPack, TrueAudio
• Lossy: MP3, Ogg Vorbis, Opus, AAC, MP4
• High-Resolution: DSD (DSF, DFF) with DoP and native playback
• Streaming: HTTP streams, Icecast, internet radio

DSD Support

rmpd includes comprehensive DSD support:

• DSD64, DSD128, DSD256 and higher sample rates
• DoP (DSD over PCM) for wider DAC compatibility
• Native DSD playback for compatible hardware
• Automatic format detection and conversion

Development

Running Tests

cargo test --workspace --all-features

Linting

# Format code
cargo fmt

# Run clippy
cargo clippy --workspace --all-targets --all-features

CI/CD

This project uses GitHub Actions for CI/CD with:

• Multi-platform testing (Ubuntu, macOS)
• Multi-architecture builds (x86_64, ARM64)
• Strict linting with Clippy
• Security audits with cargo-audit and cargo-deny
• Code coverage reporting
• Automated dependency updates via Renovate

See CI.md for detailed CI/CD documentation.

Current Status

Implemented ✅

• Core Infrastructure

  • MPD protocol server (TCP/Unix sockets)
  • Event bus system
  • Configuration management
  • Logging with tracing

• Audio Playback

  • Multi-format decoding (FLAC, MP3, Vorbis, WAV, AAC, DSD)
  • High-rate DSD support (DSD128, DSD256+)
  • Multiple output types (ALSA, PulseAudio, PipeWire)
  • Gapless playback
  • ReplayGain support

• Library Management

  • Filesystem scanning
  • SQLite database
  • Metadata extraction with lofty
  • Full-text search with tantivy
  • Album art support

• MPD Protocol

  • Core playback commands (play, pause, stop, seek)
  • Queue management (add, delete, move, shuffle)
  • Database queries (find, search, list)
  • Status and statistics
  • Playlist management
  • Output control

In Progress 🚧

• Advanced playback features (crossfade, MixRamp)
• Plugin system
• Snapcast integration
• Complete MPD protocol coverage
• OpenSubsonic support

Compatibility

Tested MPD Clients

• ✅ mpc - Command-line client
• ✅ ncmpcpp - TUI client
• ✅ Cantata - Qt GUI client
• ✅ rmpc - Modern TUI client
• 🚧 MPDroid - Android client (testing in progress)
• 🚧 MPDluxe - iOS client (testing in progress)

Multi-Room Audio

• 🚧 Snapcast - Synchronous multi-room playback (integration in progress)

Performance

rmpd is designed for efficiency:

• Startup time: < 500ms with 100k song library
• Memory usage: < 20MB idle, < 150MB with 100k songs loaded
• CPU usage: < 5% during FLAC playback
• MSRV: Rust 1.75.0+

Project Goals

1. 100% MPD Compatibility - Drop-in replacement for MPD
2. Modern Architecture - Clean, modular, testable code
3. Extensibility - Plugin system for community contributions
4. Performance - Efficient resource usage
5. Multi-Protocol - MPD, OpenSubsonic support

Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Make your changes with tests
4. Run cargo fmt and cargo clippy
5. Submit a pull request

See CI.md for development guidelines and CI/CD information.

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Acknowledgments

• Inspired by the original Music Player Daemon
• Built with modern Rust audio libraries: Symphonia, cpal, lofty
• Special thanks to the Rust audio community

Links

• Documentation: CI.md - CI/CD and development guide
• MPD Protocol: MPD Protocol Documentation
• Issue Tracker: GitHub Issues
• Discussions: GitHub Discussions