Function StreamSTTScreen

example/src/StreamSTTScreen.tsx:17–168

()

const CHUNK_SIZE = 16000 * 2 * 3;

const StreamSTTScreen = () => {
  const cactusSTT = useCactusSTT({ model: 'whisper-small' });
  const [audioFile, setAudioFile] = useState<string | null>(null);
  const [audioFileName, setAudioFileName] = useState<string>('');

  useEffect(() => {
    if (!cactusSTT.isDownloaded) {
      cactusSTT.download();
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [cactusSTT.isDownloaded]);

  const handleSelectAudio = async () => {
    try {
      const res = await DocumentPicker.pick({
        type: [DocumentPicker.types.audio],
      });
      if (res && res.length > 0) {
        const fileName = `audio_${Date.now()}.wav`;
        const destPath = `${RNFS.CachesDirectoryPath}/${fileName}`;
        await RNFS.copyFile(res[0].uri, destPath);
        setAudioFile(destPath);
        setAudioFileName(res[0].name || 'Unknown');
      }
    } catch (err) {
      console.error(err);
    }
  };

  const readAudioFile = async (filePath: string): Promise<Uint8Array> => {
    const base64Audio = await RNFS.readFile(filePath, 'base64');
    const binaryString = atob(base64Audio);
    const bytes = new Uint8Array(binaryString.length);
    for (let i = 0; i < binaryString.length; i++) {
      bytes[i] = binaryString.charCodeAt(i);
    }
    // Skip WAV header (44 bytes)
    return bytes.slice(44);
  };

  const handleStreamTranscribe = async () => {
    if (!audioFile) return;
    try {
      await cactusSTT.streamTranscribeStart({ confirmationThreshold: 0.99 });

      const pcmData = await readAudioFile(audioFile);

      for (let i = 0; i < pcmData.length; i += CHUNK_SIZE) {
        const chunk = pcmData.slice(i, i + CHUNK_SIZE);
        await cactusSTT.streamTranscribeProcess({
          audio: Array.from(chunk),
        });
      }

      await cactusSTT.streamTranscribeStop();
    } catch (err) {
      console.error('Stream error:', err);
    }