react-native-audio-data

A React Native module that provides high-performance, cross-platform access to raw audio data for analysis, visualization, and custom DSP in JavaScript and native code.

Powered by Nitro Modules and dr_libs for stable, efficient C++ audio decoding.

Features

• ⚡️ High Performance: Uses C++ directly via JSI for near-native performance.
• � Asynchronous: All decoding and waveform generation runs on background threads to keep the UI smooth.
• �🪶 Lightweight: Zero heavy dependencies like FFmpeg. Uses dr_libs for minimal footprint.
• 🔊 Format Support: Decodes MP3, WAV, and FLAC files.
• 🌊 Waveform Generation: High-speed waveform data generation for visualization. Multiple methods supported including RMS, LUFS and Abs Mean.
• 🎹 Raw PCM Data: Access raw Float32 audio samples for finding peaks, normalization, or custom processing.
• 📱 Cross-Platform: Works on iOS and Android.

Installation

npm install react-native-audio-data react-native-nitro-modules

Note: react-native-nitro-modules is a required peer dependency.

Android Setup

No additional setup is required.

iOS Setup

Install Pods:

cd ios && pod install

Usage

1. Get Raw PCM Data

Decode an audio file to get the full raw PCM data (Float32).

import { getRawPcmData } from 'react-native-audio-data';

// ...

try {
  const result = await getRawPcmData('path/to/audio/file.mp3');
  
  console.log('Channels:', result.channels);
  console.log('Sample Rate:', result.sampleRate);
  console.log('Total Frames:', result.totalPCMFrameCount);
  
  // The raw buffer (ArrayBuffer)
  // You can create a Float32Array view on it:
  const float32Data = new Float32Array(result.buffer);
  
} catch (error) {
  console.error("Failed to decode audio", error);
}

2. Generate Waveform Data

Quickly generate simplified waveform data for UI visualization (e.g., an audio player progress bar).

import { getWaveformDataByPoints, getWaveformData } from 'react-native-audio-data';

// ...

// Option A: Request points by time resolution (e.g. one point every 50ms)
const timeBasedPoints = await getWaveformData('path/to/audio/file.mp3', 50);
console.log(timeBasedPoints);
// Output: [0.02, 0.45, ...] (length depends on audio duration)

// Option B: Request a fixed number of data points (e.g. 100 points)
const fixedPoints = await getWaveformDataByPoints('path/to/audio/file.mp3', 100);
console.log(fixedPoints); 
// Output: [0.05, 0.23, ...] (100 items)

API Reference

getRawPcmData(filePath: string)

Decodes the audio file and returns the raw PCM data.

• Parameters:
  • filePath (string): Absolute path or URI to the audio file.
• Returns: Promise<AudioDataResult>
  • buffer (ArrayBuffer): Raw PCM data (Float32).
  • channels (number): Number of audio channels.
  • sampleRate (number): Sample rate in Hz.
  • totalPCMFrameCount (number): Total number of PCM frames.

getWaveformData(filePath: string, millisecondsPerPoint: number, method?: WaveformMethod)

Generates a waveform where each point represents a specific duration of audio.

• Parameters:
  • filePath (string): Absolute path or URI to the audio file.
  • millisecondsPerPoint (number): The duration each point should represent (e.g., 100ms).
  • method (WaveformMethod, optional): Calculation method. Values: 'RMS' (default), 'AbsMean', 'LUFS'.
• Returns: Promise<number[]> containing normalized values.

getWaveformDataByPoints(filePath: string, targetPoints: number, method?: WaveformMethod)

Generates a waveform with a specific fixed number of points.

• Parameters:
  • filePath (string): Absolute path or URI to the audio file.
  • targetPoints (number): The number of data points you want in the output array.
  • method (WaveformMethod, optional): Calculation method. Values: 'RMS' (default), 'AbsMean', 'LUFS'.
• Returns: Promise<number[]> containing normalized values.

resolveFilePath(filePath: string)

Utility to resolve platform-specific file paths (e.g., Android Content URIs) to absolute system paths usable by C++.

• Parameters:
  • filePath (string): The raw file path or URI.
• Returns: Promise<string> resolving to the absolute file path.

Roadmap

• Support decoding while recording (Real-time Analysis)
• Full multi-threading supported decoding

---

Contributing

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

License

MIT