A Rust application that detects the BPM (Beats Per Minute) of audio playing on your system using PipeWire for audio capture and aubio for beat detection.

• Real-time BPM detection from system audio
• Uses PipeWire to capture audio from any source on your system
• Implements aubio's tempo detection algorithm for accurate beat analysis
• Smooths BPM readings with a running average
• Includes octave error correction for more reliable results
• Displays confidence levels for detected BPM values

• Linux system with PipeWire audio server
• Rust toolchain (2024 edition)
• aubio library installed on your system

1. Make sure you have the Rust toolchain installed:

   curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
   

2. Install the aubio library:

   # Debian/Ubuntu
   sudo apt install libaubio-dev
   
   # Fedora
   sudo dnf install aubio-devel
   
   # Arch Linux
   sudo pacman -S aubio
   

3. Clone this repository:

   git clone https://github.com/yourusername/pipe-beat-detector.git
   cd pipe-beat-detector
   

4. Build the application:

   cargo build --release
   

Run the application:

cargo run --release

The application will:

1. Connect to your system's audio through PipeWire
2. Capture audio in real-time
3. Process the audio to detect beats
4. Display the current BPM with confidence levels

The BPM is displayed in the terminal with the following information:

• Corrected BPM (after smoothing and octave correction)
• Raw BPM (direct from aubio)
• Confidence level (how certain the algorithm is about the detection)
• Number of samples in the BPM history

1. Audio Capture: Uses PipeWire to capture system audio
2. Sample Processing:
   • Converts stereo audio to mono
   • Buffers audio samples in chunks
   • Processes audio in windows of 1024 samples with 50% overlap
3. BPM Detection:
   • Uses aubio's Tempo detector with HFC (High Frequency Content) onset detection
   • Filters out unreasonable BPM values (outside 30-300 BPM range)
4. BPM Smoothing:
   • Maintains a history of recent BPM readings
   • Calculates a running average for stability
5. Octave Error Correction:
   • Detects and corrects common octave errors (halving/doubling of actual tempo)
   • Uses confidence levels to determine when correction is needed

The application uses the following default settings:

• Buffer size: 1024 samples
• Hop size: 512 samples (50% overlap)
• BPM history size: 5 readings
• Silence threshold: -40.0 dB
• Onset detection threshold: 0.1
• Valid BPM range: 30-300 BPM

MIT

• PipeWire - For the audio capture API
• aubio - For the audio beat tracking algorithms