import { EncodedAudioChunk } from 'node-webcodecs';

// Create from encoded AAC data
const chunk = new EncodedAudioChunk({
  type: 'key',           // Audio chunks are typically all 'key'
  timestamp: 0,          // Presentation time in microseconds
  duration: 21333,       // Duration in microseconds (~21ms for AAC frame)
  data: encodedAACData   // Uint8Array or ArrayBuffer
});

// Access properties
console.log(chunk.type);       // 'key'
console.log(chunk.timestamp);  // 0
console.log(chunk.byteLength); // Size of encoded data

// Copy data to another buffer
const buffer = new Uint8Array(chunk.byteLength);
chunk.copyTo(buffer);

new EncodedAudioChunk(init: EncodedAudioChunkInit)

chunk.copyTo(destination: BufferSource): void

type EncodedAudioChunkType = 'key' | 'delta';

interface EncodedAudioChunkInit {
  type: EncodedAudioChunkType;  // Required: 'key' or 'delta'
  timestamp: number;            // Required: microseconds
  duration?: number;            // Optional: microseconds
  data: BufferSource;           // Required: encoded data
}

import { AudioEncoder, AudioData } from 'node-webcodecs';

const encoder = new AudioEncoder({
  output: (chunk, metadata) => {
    // chunk is an EncodedAudioChunk
    console.log(`Got audio chunk at ${chunk.timestamp}μs`);
    console.log(`Size: ${chunk.byteLength} bytes`);
    console.log(`Duration: ${chunk.duration}μs`);

    // Copy to your own buffer for storage/transmission
    const data = new Uint8Array(chunk.byteLength);
    chunk.copyTo(data);

    // First chunk includes decoder config in metadata
    if (metadata?.decoderConfig) {
      console.log('Decoder config:', metadata.decoderConfig);
    }
  },
  error: (e) => console.error('Encoding error:', e)
});

encoder.configure({
  codec: 'mp4a.40.2',     // AAC-LC
  sampleRate: 48000,
  numberOfChannels: 2,
  bitrate: 128_000
});

import { AudioDecoder, EncodedAudioChunk } from 'node-webcodecs';

const decoder = new AudioDecoder({
  output: (audioData) => {
    console.log(`Decoded: ${audioData.numberOfFrames} samples`);
    console.log(`Format: ${audioData.format}`);
    audioData.close();  // Don't forget to close!
  },
  error: (e) => console.error('Decoding error:', e)
});

decoder.configure({
  codec: 'mp4a.40.2',
  sampleRate: 48000,
  numberOfChannels: 2
});

// Decode a chunk
const chunk = new EncodedAudioChunk({
  type: 'key',
  timestamp: 0,
  data: aacFrameData
});

decoder.decode(chunk);
await decoder.flush();