Package Exports

carta1
carta1/codec/index.js

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Readme

Carta1

An ATRAC1 audio codec implementation in JS.

Features

Pure JavaScript implementation of ATRAC1 codec
Encoding WAV to AEA (ATRAC1) format
Decoding AEA to WAV format
Command-line interface
Browser-compatible with Web Workers
Streaming support for large files

Installation

npm install carta1

CLI Usage

Encoding

carta1 --encode input.wav output.aea

Decoding

carta1 --decode input.aea output.wav

Options

-e, --encode - Encode WAV to AEA
-d, --decode - Decode AEA to WAV
-j, --json - Dump AEA file structure to JSON
-q, --quiet - Suppress all output except errors
-f, --force - Overwrite output file if it exists
-t, --title <title> - Custom title for AEA file metadata (encoding only)

Browser Usage

<script src="https://unpkg.com/carta1/dist/carta1-worker.min.js"></script>
<script src="https://unpkg.com/carta1/dist/carta1-worker-interface.min.js"></script>

// Create codec instance
const codec = new Carta1Worker('carta1-worker.min.js')

// Encode PCM to ATRAC1
const result = await codec.encode(pcmData, options)

// Decode ATRAC1 to PCM
const wavData = await codec.decode(aeaData)

// Clean up
codec.terminate()

API Reference

Node.js

import { encode, decode, AudioProcessor } from 'carta1'

// Encode PCM frames
const encoder = encode(options)
const encodedFrame = encoder(pcmFrame)

// Decode ATRAC1 frames
const decoder = decode()
const pcmFrame = decoder(encodedFrame)

Browser Worker API

`new Carta1Worker(workerPath)`

Create a new codec worker instance.

`encode(pcmData, options)`

Encode PCM audio data to ATRAC1 format.

`decode(aeaData)`

Decode ATRAC1 data to PCM format.

`parseAeaBlob(blob)`

Parse AEA file blob to extract metadata.

`terminate()`

Clean up worker resources.

Development

# Install dependencies
npm install

# Run tests
npm test

# Build minified versions
npm run build

# Lint code
npm run lint

# Format code
npm run format

Acknowledgements

This project would not have been possible without:

AtracDEnc by Daniel Cherednik - The reference ATRAC implementation that provided invaluable insights into the codec's inner workings and served as the primary source for understanding the ATRAC1 format specification.

License

ISC