OpenDroidMic

Turn your Android phone into a low-latency microphone for Linux.

Android → Wi-Fi/UDP → Opus → PipeWire → Any Linux application.

Android Phone ──── Wi-Fi ────► Linux PC ──── PipeWire ────► Discord/OBS/Browser
  AudioRecord                    UDP receiver                 "OpenDroidMic"
  Opus encode                    Opus decode
  48kHz mono                     Jitter buffer

Quick Start

Option A: Download pre-built binary (recommended)

Go to Releases and download the latest version:

• Linux x86_64: opendroidmic-*-linux-amd64.tar.gz
• Android: opendroidmic-*-android.apk

# Linux
tar xzf opendroidmic-*-linux-amd64.tar.gz
cd opendroidmic-*
./opendroidmic

# Android — transfer APK to phone and install, or:
adb install opendroidmic-*-android.apk

The binaries only need PipeWire and libopus at runtime (which PipeWire-based distros already have).

Option B: Build from source

1. Install system dependencies

Arch/CachyOS:

sudo pacman -S rust pipewire opus pkg-config

Debian/Ubuntu:

sudo apt install rustc cargo libpipewire-0.3-dev libopus-dev pkg-config build-essential

Fedora:

sudo dnf install rust pipewire-devel opus-devel pkg-config gcc

2. Build the Linux receiver

git clone https://github.com/dereferencex/opendroidmic.git
cd opendroidmic/linux
cargo build --release

Binary at: target/release/opendroidmic

3. Start the receiver

./target/release/opendroidmic

You should see:

OpenDroidMic v0.1.0
PipeWire virtual source started: 48000 Hz, 1 ch, 960 samples/frame
Listening for Android connections on port 38471...

4. Install the Android app

# If you have ADB:
cd opendroidmic/android
./gradlew assembleDebug
adb install app/build/outputs/apk/debug/app-debug.apk

# Or open android/ in Android Studio and click Run

5. Connect

1. Open OpenDroidMic on your phone
2. Enter your Linux PC's IP address and port 38471
3. Tap Start Streaming
4. Grant microphone permission
5. Select "OpenDroidMic" as mic in Discord/OBS/Browser/etc.

Find your PC's IP: ip addr show | grep "inet "

Features

• Low latency — ~20ms glass-to-glass on local Wi-Fi
• Opus codec — 32kbps, 48kHz mono, excellent quality at low bitrate
• PipeWire virtual mic — appears as a real microphone in all Linux apps
• Adaptive jitter buffer — auto-tunes 1-5 frames based on network conditions
• Auto-reconnect — exponential backoff (500ms → 8s), up to 10 attempts
• Keepalive — PING/PONG every 5s, detects dead connections in 15s
• mDNS discovery — auto-finds receiver on local network (Avahi/Zeroconf)
• QR code pairing — run ./opendroidmic --qr, scan from phone
• Background streaming — foreground service, notification shows connection status
• Last-used memory — remembers host/port between sessions

CLI Options

./opendroidmic                          # Default: port 38471
./opendroidmic --port 5000              # Custom port
./opendroidmic --verbose                # Detailed logging
./opendroidmic --qr                     # Print QR code for pairing
./opendroidmic --port 5000 --qr --verbose  # Combine options

Connection Methods

Manual — Type IP:port in the app.

Auto-discover — Requires Avahi on Linux:

# Install Avahi
sudo pacman -S avahi nss-mdns        # Arch
sudo apt install avahi-daemon libnss-mdns  # Debian

# Enable
sudo systemctl enable --now avahi-daemon

# Install OpenDroidMic service
sudo cp linux/avahi/opendroidmic.service /etc/avahi/services/
sudo systemctl restart avahi-daemon

QR code — Run ./opendroidmic --qr, scan from the app.

Requirements

Component	Pre-built binary (download)	Build from source
Linux runtime	PipeWire 1.0+, libopus	Same
Linux build	None	Rust 1.75+, libpipewire-dev, libopus-dev
Android	Android 8.0+ (API 26)	+ Android SDK + JDK 17

Test Without Phone

# Terminal 1: Start receiver
./target/release/opendroidmic

# Terminal 2: Send synthetic 440Hz tone
./target/release/opendroidmic-test-sender 127.0.0.1:38471

Troubleshooting

"OpenDroidMic" doesn't appear in mic list:

wpctl status                    # Check PipeWire nodes
pw-cli ls Node | grep -i mic    # Search for virtual mic

Android stuck on "Waiting for server...":

• Verify same network: both on same Wi-Fi
• Check receiver is running: ss -ulnp | grep 38471
• Open UDP port: sudo iptables -I INPUT -p udp --dport 38471 -j ACCEPT
• Try loopback first: run receiver + test sender on same machine

No audio / choppy audio:

• Use 5GHz Wi-Fi instead of 2.4GHz
• Move closer to router
• Check receiver stats for packet loss/jitter
• Close other bandwidth-heavy apps

Permission denied on ./gradlew:

chmod +x android/gradlew

PipeWire not found (build error):

# Arch
sudo pacman -S pipewire pipewire-pulse

# Debian/Ubuntu
sudo apt install libpipewire-0.3-dev pipewire

# Fedora
sudo dnf install pipewire-devel pipewire-pulse

Project Structure

opendroidmic/
├── android/                        # Android app (Kotlin)
│   ├── app/src/main/java/com/opendroidmic/
│   │   ├── MainActivity.kt         # UI + discovery + QR
│   │   ├── AudioStreamService.kt   # Foreground service + reconnect
│   │   ├── OpusEncoderWrapper.kt   # Concentus Opus encoder
│   │   ├── Protocol.kt             # Binary packet format
│   │   ├── DiscoveryManager.kt     # mDNS/NSD discovery
│   │   └── QrScanActivity.kt       # CameraX + ML Kit QR scanner
│   └── app/build.gradle.kts
│
├── linux/                          # Linux receiver (Rust)
│   ├── src/
│   │   ├── main.rs                 # Entry point + UDP receiver
│   │   ├── pipewire.rs             # PipeWire virtual source
│   │   ├── protocol.rs             # Binary protocol (7 packet types)
│   │   ├── opus_dec.rs             # Opus decoder
│   │   ├── audio_buffer.rs         # Shared PCM ring buffer
│   │   ├── jitter.rs               # Adaptive jitter buffer
│   │   └── test_sender.rs          # Test audio sender
│   ├── avahi/                      # mDNS service files
│   └── Cargo.toml
│
├── protocol/PROTOCOL.md            # Full protocol specification
├── README.md
└── CONTRIBUTING.md

Protocol

Quick summary — full spec in protocol/PROTOCOL.md:

Type	ID	Direction	Description
HELLO	0	Client→Server	Session token (8 bytes)
HELLO_ACK	1	Server→Client	Accept connection
AUDIO	2	Client→Server	Opus frame + seq + timestamp
PING	3	Client→Server	Keepalive request
PONG	4	Server→Client	Keepalive response
STOP	5	Both	Graceful disconnect
ERROR	6	Server→Client	Error with message

20-byte header: magic ODMC + version + type + flags + seq + timestamp + payload_len + checksum.

License

MIT License