bidah/react-native-hifi/audio

Audio

Software Mansion's production audio patterns for React Native.

AudioContext and AudioRecorder as Singletons

Encapsulate AudioContext in a singleton class that manages lifecycle, audio nodes, and playback methods. This separates audio logic from React components and makes state consistent across the app. Multiple AudioContext instances can end up in conflicting states (one running, another suspended) if not actively managed.

// AudioManager.ts
import { AudioContext } from 'react-native-audio-api';
class AudioManager {
  private static instance: AudioManager;
  readonly context: AudioContext;
  private constructor() {
    this.context = new AudioContext();
  }
  static getInstance(): AudioManager {
    if (!AudioManager.instance) {
      AudioManager.instance = new AudioManager();
    }
    return AudioManager.instance;
  }
}
export const audioManager = AudioManager.getInstance();

The same principle applies to AudioRecorder — instantiate once and reuse.

// recorder.ts
import { AudioRecorder } from 'react-native-audio-api';
export const recorder = new AudioRecorder();

Storing AudioBuffers in State

AudioBuffer objects are safe to store in React state, Zustand, Redux, or any state container. The buffer holds a reference to native memory — copying that reference into state does not copy the audio data, so there is no performance concern.

const [buffer, setBuffer] = useState<AudioBuffer | null>(null);
async function load(uri: string) {
  const loaded = await audioContext.decodeAudioData(uri);
  setBuffer(loaded);
}

Animations Driven by Raw Audio Data

When visualizing audio data (waveforms, frequency bars, volume meters), mutate the existing typed array in place using the shared value modify method rather than creating a new array on every frame.

import { useSharedValue } from 'react-native-reanimated';
const amplitudes = useSharedValue(new Float32Array(64));
function onAudioFrame(data: Float32Array) {
  amplitudes.modify((prev) => {
    for (let i = 0; i < prev.length; i++) {
      prev[i] = data[i];
    }
    return prev;
  });
}

Assigning amplitudes.value = new Float32Array(data) allocates and garbage-collects at 60 fps or higher, causing jank. modify mutates the existing allocation on the UI thread, skipping GC entirely.

Session Category for Recording and Playback

Use the playAndRecord session category for any feature that involves recording, or that mixes recording and playback. Only choose a narrower category when the use case explicitly rules out recording.

import { setAudioModeAsync } from 'react-native-audio-api';
await setAudioModeAsync({
  iosCategory: 'playAndRecord',
  iosCategoryOptions: ['defaultToSpeaker', 'allowBluetooth'],
});

playAndRecord keeps the microphone accessible, enables Bluetooth HFP devices, and routes playback correctly. Switching to a narrower category (e.g., playback) mid-session requires a full deactivation/reactivation cycle, which is expensive.

Session Activation and Deactivation

Session activation and deactivation are time-expensive native calls. Activate once when the audio feature mounts and deactivate once when it unmounts — not around individual playback or recording operations.

Use suspend() when audio is temporarily not needed, and close() when audio is done permanently. A running AudioContext plays silence even with no source nodes connected, draining battery. On iOS, a running AudioContext also prevents the lock screen from showing a paused state.

useEffect(() => {
  async function startSession() {
    await setAudioModeAsync({ iosCategory: 'playAndRecord' });
    await audioContext.resume();
  }
  startSession();
  return () => {
    // suspend() for temporary pause (screen unmounts but audio may resume later)
    audioContext.suspend();
  };
}, []);

Call close() when the audio feature is permanently torn down to release system resources:

audioContext.close();

Wrapping every sound play or record call in activate/deactivate pairs adds perceptible latency and unnecessarily interrupts other apps' audio.

References

• React Native Audio API docs