audio-analysis-core/README.md

React Native audio analysis library with waveform extraction and full audio analysis

# Audio Analysis Core

A React Native library for audio analysis with waveform extraction and comprehensive audio feature extraction.

## Features

- **Waveform Extraction**: Extract waveform data from audio files
- **Full Audio Analysis**: Comprehensive audio analysis including spectrum, RMS, zero-crossing rate, and more
- **TypeScript Support**: Full TypeScript definitions included
- **Cross-Platform**: Works on both iOS and Android

## Installation

```bash
npm install audio-analysis-core
# or
yarn add audio-analysis-core
```

### iOS Setup

```bash
cd ios && pod install && cd ..
```

### Android Setup

No additional setup required for Android.

## Usage

### Basic Waveform Extraction

```typescript
import { extractWaveform } from 'audio-analysis-core';

const waveform = await extractWaveform({
  fileUri: 'file://path/to/audio.mp3',
  pointsPerSecond: 50, // points per second
  startTimeMs: 0, // start time in milliseconds
  endTimeMs: 10000, // end time in milliseconds (optional)
  decodingOptions: {
    sampleRate: 44100,
    channels: 1,
    bitDepth: 16
  }
});

console.log(waveform.data); // Array of waveform values
console.log(waveform.duration); // Duration in seconds
console.log(waveform.sampleRate); // Sample rate
console.log(waveform.channels); // Number of channels
console.log(waveform.bitDepth); // Bit depth
```

### Full Audio Analysis

```typescript
import { analyzeAudio } from 'audio-analysis-core';

const analysis = await analyzeAudio({
  fileUri: 'file://path/to/audio.mp3',
  segmentDurationMs: 100, // duration of each data point in milliseconds
  startTimeMs: 0, // start time in milliseconds
  endTimeMs: 10000, // end time in milliseconds (optional)
  features: {
    energy: true,
    rms: true,
    zcr: true,
    spectralCentroid: true,
    mfcc: false
  },
  decodingOptions: {
    sampleRate: 44100,
    channels: 1,
    bitDepth: 16
  }
});

console.log(analysis.dataPoints); // Array of data points
console.log(analysis.durationMs); // Duration in milliseconds
console.log(analysis.sampleRate); // Sample rate
console.log(analysis.numberOfChannels); // Number of channels
```

## API Reference

### `extractWaveform(options)`

Extract waveform data from an audio file (similar to expo-audio-stream's extractPreview).

**Parameters:**
- `options.fileUri` (string): Path to the audio file
- `options.pointsPerSecond` (number, optional): Points per second to extract (default: 50)
- `options.startTimeMs` (number, optional): Start time in milliseconds (default: 0)
- `options.endTimeMs` (number, optional): End time in milliseconds (default: entire file)
- `options.decodingOptions` (DecodingOptions, optional): Decoding configuration

**Returns:** Promise<WaveformData>

### `analyzeAudio(options)`

Perform comprehensive audio analysis (similar to expo-audio-stream's extractAudioAnalysis).

**Parameters:**
- `options.fileUri` (string): Path to the audio file
- `options.segmentDurationMs` (number, optional): Duration of each data point in milliseconds (default: 100)
- `options.startTimeMs` (number, optional): Start time in milliseconds (default: 0)
- `options.endTimeMs` (number, optional): End time in milliseconds (default: entire file)
- `options.features` (AudioFeatures, optional): Features to extract
- `options.decodingOptions` (DecodingOptions, optional): Decoding configuration

**Returns:** Promise<AudioAnalysisResult>

## Types

```typescript
interface WaveformData {
  data: number[];
  duration: number;
  sampleRate: number;
  channels: number;
  bitDepth: number;
}

interface AudioFeatures {
  energy?: boolean;
  rms?: boolean;
  zcr?: boolean;
  spectralCentroid?: boolean;
  mfcc?: boolean;
  waveform?: boolean;
  spectrum?: boolean;
}

interface DecodingOptions {
  sampleRate?: number;
  channels?: number;
  bitDepth?: number;
}

interface AudioAnalysisDataPoint {
  amplitude: number;
  rms: number;
  db: number;
  energy?: number;
  zcr?: number;
  spectralCentroid?: number;
  mfcc?: number[];
}

interface AudioAnalysisResult {
  segmentDurationMs: number;
  durationMs: number;
  bitDepth: number;
  samples: number;
  numberOfChannels: number;
  sampleRate: number;
  dataPoints: AudioAnalysisDataPoint[];
}
```

## License

MIT