Class AudioRecognitionUsage

samples/AudioRecognitionUsage.java:21–162

import io.reactivex.schedulers.Schedulers;

public final class AudioRecognitionUsage {
  private final AudioFormat format = buildAudioFormatInstance();
  private volatile boolean stopped;

  public TargetDataLine getTargetDataLineForRecord() throws LineUnavailableException {
    TargetDataLine microphone = AudioSystem.getTargetDataLine(format);
    System.out.println(microphone.getBufferSize());
    microphone.open();
    return microphone;
  }

  public Flowable<ByteBuffer> getMicrophoneStreaming() {
    Flowable<ByteBuffer> audios =
        Flowable.<ByteBuffer>create(
            emitter -> {
              try {
                final TargetDataLine line = getTargetDataLineForRecord();
                int frameSizeInBytes = format.getFrameSize();
                System.out.println(
                    String.format(
                        "Frame size in bytes: %s, %s", frameSizeInBytes, format.getEncoding()));
                final int bufferLengthInBytes = 1024 * frameSizeInBytes;
                int numBytesRead;
                line.start();
                int c = 0;
                byte[] data = new byte[bufferLengthInBytes];
                while (!stopped && c < 100) {
                  if ((numBytesRead = line.read(data, 0, bufferLengthInBytes)) == -1) {
                    break;
                  } else {
                    System.out.println(String.format("Read microphone %s data", numBytesRead));
                    emitter.onNext(ByteBuffer.wrap(data, 0, numBytesRead));
                  }
                  if (c % 10 == 0) {
                    System.out.println(String.format("Sending %d packages", c));
                  }
                  ++c;
                }
                emitter.onComplete();
              } catch (Exception ex) {
                ex.printStackTrace();
                emitter.onError(ex);
              }
            },
            BackpressureStrategy.BUFFER);
    return audios;
  }

  public AudioFormat buildAudioFormatInstance() {
    final AudioFormat.Encoding ENCODING = AudioFormat.Encoding.PCM_SIGNED;
    final float RATE = 16000.0f;
    final int CHANNELS = 1;
    final int SAMPLE_SIZE = 16;
    final boolean BIG_ENDIAN = false;
    return new AudioFormat(ENCODING, RATE, SAMPLE_SIZE, CHANNELS, 2, RATE, BIG_ENDIAN);
  }

  public Flowable<ByteBuffer> getStreamingDataFromFile(String filePath) {