sclass OpusMachine implements IF0_Int, AutoCloseable {
  InputStream in;
  new ByteArraysPartialInputStream buffer;
  new ArraysShortStream sampleStream;
  OpusFromStream opusDecoder;
  int channels = 1;
  
  *(InputStream *in) {}
  
  void init() ctex {
    opusDecoder if null = new OpusFromStream(buffer, channels);
  }
  
  close { dispose in; }
  
  bool pullFromDecoder() ctex {
    while ping (true) {
      short[] samples;
      if ((samples = opusDecoder.nextSamples()) != null)
        ret true with sampleStream.add(samples);

      if (!pullFromSource()) false; // end of stuff
      // we got new material from source, decode again
    }
  }
  
  bool pullFromSource() {
    ret fillBuffer();
  }
  
  swappable bool fillBuffer() {
    if (in != null) {
      byte[] buf = new[primarybufSize];
      int n = in.read(buf);
      if (n >= 0) {
        buffer.write(takeFirst(buf, n));
        true;
      }
    }
    false;
  }
  
  // get next sample (pull mode)
  public int get() ctex {
    init();
    int sample;
    while ping ((sample = sampleStream.read()) == Int.MAX_VALUE) {
      if (!pullFromDecoder())
        ret Int.MAX_VALUE;
    }
    ret sample;
  }
}