PulseLink

PulseLink is an audio streaming application that allows you to transmit audio between your Android phone and Linux computer. It supports two main modes: streaming audio from your Android phone to your Linux speakers, and routing your laptop microphone to the speakers.

Known Limitation: When using the Local Audio feature with headphones connected, the audio will currently not output through your laptop speakers. We are actively investigating solutions for this hardware-level limitation and will update the app once resolved.

Features

Android to Linux Streaming

• Stream microphone audio from your Android phone to your Linux computer over WiFi
• Low-latency UDP audio transmission
• Audio level visualization on both devices
• Automatic server discovery via QR code scanning

Local Audio Routing

• Route your laptop microphone directly to speakers
• Force speakers to output audio even when headphones are connected
• ALSA-level control to bypass PulseAudio port restrictions
• Useful for testing microphones or creating a local PA system

Requirements

Android

• Android 7.0 (API 24) or higher
• Microphone permission
• Camera permission (for QR code scanning)
• WiFi connection to the same network as your Linux computer

Linux

• Python 3.10 or higher
• GTK 4
• PipeWire or PulseAudio
• The following Python packages: PyGObject, pulsectl, sounddevice, numpy, scipy
• ALSA utilities (amixer) for speaker control

Installation

Android

Download the APK from the Releases page or build from source:

./gradlew assembleRelease

The APK will be in app/build/outputs/apk/release/.

Linux

Option 1: Run from source

cd Linux
python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt
python main.py

Option 2: AppImage

Download the AppImage from the Releases page, make it executable, and run:

chmod +x PulseLink-*.AppImage
./PulseLink-*.AppImage

On first run, the app will prompt you to install Python dependencies. This creates a local environment in ~/.config/pulselink/ and only needs to be done once.

System Requirements:

• GTK4 and libadwaita must be installed:

  sudo apt install python3-gi python3-gi-cairo gir1.2-gtk-4.0 gir1.2-adw-1 libportaudio2

Usage

Android to Linux Audio Streaming

1. Start the Linux application and select "Android Device" mode
2. Click "Start Server" to begin listening for connections
3. Note the IP address displayed or scan the QR code with your Android phone
4. On your Android phone, open PulseLink and tap "Scan QR Code"
5. Grant microphone permission when prompted
6. Start streaming - audio from your phone microphone will play through your Linux speakers

Local Microphone to Speakers

1. Start the Linux application
2. Select "Local Microphone" mode
3. Choose your input device (microphone) from the dropdown
4. Choose your output device (speakers) from the dropdown
5. If you want to use speakers while headphones are connected:
   • Check "Force Speakers On"
   • Check "Mute Headphones"
6. Click "Start Audio"

Building from Source

Android

Requires Android Studio or the Android SDK with Gradle.

# Debug build
./gradlew assembleDebug

# Release build
./gradlew assembleRelease

Linux AppImage

Requires PyInstaller and appimagetool.

cd Linux
pip install pyinstaller
pyinstaller --onefile --name pulselink --add-data "style.css:." main.py

# Then use appimagetool to create the AppImage

Project Structure

PulseLink/
├── app/                    # Android application source
│   └── src/main/java/     # Kotlin source files
├── Linux/                  # Linux application source
│   ├── main.py            # Application entry point
│   ├── server.py          # UDP audio server
│   ├── local_audio.py     # Local microphone routing
│   ├── ui/                # GTK 4 user interface
│   └── style.css          # Application styling
├── .github/workflows/      # CI/CD configuration
└── README.md

Technical Details

Audio Format

• Sample rate: 48000 Hz
• Channels: Mono
• Bit depth: 16-bit signed little-endian PCM
• Frame size: 960 samples (20ms)

Network Protocol

• UDP for audio data transmission
• Packet format: 4-byte sequence number followed by raw PCM audio data
• Default port: 5555

Troubleshooting

No audio playing on Linux

• Check that your audio output device is selected correctly
• Verify that PipeWire or PulseAudio is running
• Try a different output device in the dropdown

Speakers unavailable when headphones connected

• Enable "Force Speakers On" checkbox
• This disables ALSA auto-mute and directly enables the speaker channel

High latency or audio stuttering

• Ensure both devices are on the same WiFi network
• Reduce distance between devices and router
• Close other network-intensive applications

Connection issues

• Verify both devices are on the same network
• Check that port 5555 is not blocked by a firewall
• Try restarting the server on the Linux side

License

This project is open source. See the LICENSE file for details.

Contributing

Contributions are welcome. Please open an issue or submit a pull request on GitHub.

Developer

This project is developed by Uzair Developer. GitHub