Expo Play Audio Stream 🎶

The Expo Play Audio Stream module is a powerful tool for streaming audio data in your Expo-based React Native applications. It provides a seamless way to play audio chunks in real-time, allowing you to build audio-centric features like voice assistants, audio players, and more.

Motivation 🎯

Expo's built-in audio capabilities are limited to playing pre-loaded audio files. The Expo Audio Stream module was created to address this limitation, enabling developers to stream audio data dynamically and have more control over the audio playback process.

Example Usage 🚀

Here's an example of how you can use the Expo Audio Stream module to play a sequence of audio chunks:

import { ExpoPlayAudioStream } from 'expo-audio-stream';

// Assuming you have some audio data in base64 format
const sampleA = 'base64EncodedAudioDataA';
const sampleB = 'base64EncodedAudioDataB';

useEffect(() => {
  async function playAudioChunks() {
    try {
      await ExpoPlayAudioStream.setVolume(100);
      await ExpoPlayAudioStream.streamRiff16Khz16BitMonoPcmChunk(sampleA);
      console.log('Streamed A');
      await ExpoPlayAudioStream.streamRiff16Khz16BitMonoPcmChunk(sampleB);
      console.log('Streamed B');
      console.log('Streaming A & B');
      ExpoPlayAudioStream.streamRiff16Khz16BitMonoPcmChunk(sampleA);  
      ExpoPlayAudioStream.streamRiff16Khz16BitMonoPcmChunk(sampleB);
    } catch (error) {
      console.error(error);
    }
  }

  playAudioChunks();
}, []);

API 📚

The Expo Play Audio Stream module provides the following API:

• streamRiff16Khz16BitMonoPcmChunk(base64Chunk: string): Promise<void>: Streams a base64-encoded audio chunk in the RIFF format with 16 kHz, 16-bit, mono PCM encoding.
• setVolume(volume: number): Promise<void>: Sets the volume of the audio playback, where volume is a value between 0 and 100.
• pause(): Promise<void>: Pauses the audio playback.
• start(): Promise<void>: Starts the audio playback.
• stop(): Promise<void>: Stops the audio playback and clears any remaining audio data.

Swift Implementation 🍎

The Swift implementation of the Expo Audio Stream module uses the AVFoundation framework to handle audio playback. It utilizes a dual-buffer queue system to ensure smooth and uninterrupted audio streaming. The module also configures the audio session and manages the audio engine and player node.

Kotlin Implementation 🤖

The Kotlin implementation of the Expo Audio Stream module uses the AudioTrack class from the Android framework to handle audio playback. It uses a concurrent queue to manage the audio chunks and a coroutine-based playback loop to ensure efficient and asynchronous processing of the audio data.

Limitations and Considerations ⚠️

• The Expo Play Audio Stream module is designed to work with specific audio formats (RIFF, 16 kHz, 16-bit, mono PCM). If your audio data is in a different format, you may need to convert it before using the module.
• The module does not provide advanced features like audio effects, mixing, or recording. It is primarily focused on real-time audio streaming.
• The performance of the module may depend on the device's hardware capabilities and the complexity of the audio data being streamed.

Contributions 🤝

Contributions to the Expo Audio Stream module are welcome! If you encounter any issues or have ideas for improvements, feel free to open an issue or submit a pull request on the GitHub repository.

License 📄

The Expo Play Audio Stream module is licensed under the MIT License.