@ra2web/wavefile/README.md

WAV file processing library from ra2web project

# @ra2web/wavefile

A WAV file processing library extracted from the ra2web project. This library provides comprehensive functionality for reading, writing, and manipulating WAV audio files.

## Features

- Read and write WAV files
- Support for various bit depths (8, 16, 24, 32, 64-bit)
- Support for floating-point audio formats (32f, 64)
- Audio compression formats (IMA-ADPCM, A-Law, μ-Law)
- Sample rate conversion
- Bit depth conversion
- Audio format conversion
- Base64 encoding/decoding
- Data URI support

## Installation

```bash
npm install @ra2web/wavefile
```

## Usage

### Basic Usage

```javascript
import { WaveFile } from '@ra2web/wavefile';

// Create a new WaveFile instance
const wav = new WaveFile();

// Load from buffer
const buffer = /* your audio buffer */;
wav.fromBuffer(buffer);

// Access audio properties
console.log('Sample Rate:', wav.fmt.sampleRate);
console.log('Channels:', wav.fmt.numChannels);
console.log('Bit Depth:', wav.bitDepth);

// Get samples
const samples = wav.getSamples();

// Convert to different formats
wav.toBitDepth('16');
wav.toSampleRate(44100);

// Export as buffer
const outputBuffer = wav.toBuffer();
```

### Format Conversion

```javascript
// Convert to different compression formats
wav.toALaw();        // Convert to A-Law
wav.toMuLaw();       // Convert to μ-Law
wav.toIMAADPCM();    // Convert to IMA-ADPCM

// Convert from compressed formats
wav.fromALaw();
wav.fromMuLaw();
wav.fromIMAADPCM();
```

### Base64 and Data URI Support

```javascript
// Convert to Base64
const base64String = wav.toBase64();

// Load from Base64
wav.fromBase64(base64String);

// Convert to Data URI
const dataUri = wav.toDataURI();

// Load from Data URI
wav.fromDataURI(dataUri);
```

## API Reference

### WaveFile Class

#### Constructor
- `new WaveFile(buffer?)` - Create a new WaveFile instance, optionally from a buffer

#### Methods

##### File I/O
- `fromBuffer(buffer)` - Load WAV data from a buffer
- `toBuffer()` - Export WAV data as a buffer
- `fromBase64(base64String)` - Load WAV data from Base64 string
- `toBase64()` - Export WAV data as Base64 string
- `fromDataURI(dataUri)` - Load WAV data from Data URI
- `toDataURI()` - Export WAV data as Data URI

##### Format Conversion
- `toBitDepth(bitDepth, dithered?)` - Convert bit depth
- `toSampleRate(sampleRate, options?)` - Convert sample rate
- `toRIFF()` - Convert to RIFF format
- `toRIFX()` - Convert to RIFX format

##### Compression
- `toALaw()` - Convert to A-Law compression
- `fromALaw(bitDepth?)` - Convert from A-Law compression
- `toMuLaw()` - Convert to μ-Law compression
- `fromMuLaw(bitDepth?)` - Convert from μ-Law compression
- `toIMAADPCM()` - Convert to IMA-ADPCM compression
- `fromIMAADPCM(bitDepth?)` - Convert from IMA-ADPCM compression

##### Audio Data
- `getSamples(interleaved?)` - Get audio samples

#### Properties
- `fmt` - Format chunk data
- `data` - Audio data chunk
- `bitDepth` - Current bit depth
- `container` - Container format (RIFF/RIFX/RF64)

## License

MIT

## Contributing

This library was extracted from the ra2web project. For issues and contributions, please refer to the original project repository.