react-native-pitchy

A real-time pitch detection library for React Native.

Installation

1. Install the library using a package manager of your choice:

npm install react-native-pitchy

2. Linking (iOS only):

npx pod-install

3. Rebuild your app after installing the package.

On iOS simulators, pitch detection may not work as expected due to the lack of microphone support. Make sure to test on a real device.

Permissions

Microphone permissions are required for pitch detection to work. Make sure to request the necessary permissions before starting pitch detection. You can use a library like react-native-permissions to request permissions.

iOS

Microphone

Android

RECORD_AUDIO

Usage

1. Import the library:

import Pitchy, { PitchyConfig, PitchyEventCallback } from 'react-native-pitchy';

2. (Optional) Configure Pitchy before initialization:

const config: PitchyConfig = {
  bufferSize: 4096, // Adjust buffer size for performance vs accuracy
  minVolume: -60, // Minimum volume threshold for pitch detection (in dB)
};

3. Initialize Pitchy with the optional configuration:

Pitchy.init(config);

4. Start pitch detection:

Pitchy.start().then(() => {
  console.log('Pitch detection started!');
});

5. Listen to pitch events:

const handlePitchDetected: PitchyEventCallback = (data) => {
  console.log('Pitch detected:', data.pitch);
};

const subscription = Pitchy.addListener(handlePitchDetected);

// Remember to unsubscribe later to avoid memory leaks
subscription.remove();

6. Stop pitch detection:

Pitchy.stop().then(() => {
  console.log('Pitch detection stopped!');
});

7. Check if pitch detection is running:

Pitchy.isRecording().then((isRecording) => {
  console.log('Pitch detection is recording:', isRecording);
});

API

Types

• PitchyAlgorithm: String representing the pitch detection algorithm (currently only supports "ACF2+")
• PitchyConfig: Configuration object for Pitchy.init
  • bufferSize: (optional) Number representing the audio buffer size (default: 4096)
  • minVolume: (optional) Number representing the minimum volume threshold (default: -60)
  • algorithm: (optional) PitchyAlgorithm used for detection (default: "ACF2+")
• PitchyEventCallback: Function called when pitch is detected. Receives an object with a pitch property (number)

Methods

• Pitchy.init(config?: PitchyConfig): Initializes Pitchy with an optional configuration.
• Pitchy.start(): Starts pitch detection and returns a Promise.
• Pitchy.stop(): Stops pitch detection and returns a Promise.
• Pitchy.isRecording(): Checks if pitch detection is currently running and returns a Promise resolving to a boolean.
• Pitchy.addListener(callback: PitchyEventCallback): Adds a listener for the onPitchDetected event.

Roadmap

• Fix example app (permissions issue related to builder-bob)
• Add FFT for ACF2+ algorithm (currently uses a naive implementation)
• Add more pitch detection algorithms

Examples

Check out the example app for a simple implementation of pitch detection using Pitchy.

Contributing

See the contributing guide to learn how to contribute to the repository and the development workflow.

License

MIT