private static void compareGbAudio(GbAudio a, GbAudio b) {
    for (int i = 0; i < Math.min(a.soValues.length,  b.soValues.length); i++) {
      if (a.soValues[i] != b.soValues[i]) {
        System.out.println("diff so " + i + ": " + a.soValues[i] + " " + b.soValues[i]);
        break;
      }
    }
    for (int i = 0; i < Math.min(a.samples.length,  b.samples.length); i++) {
      if (a.samples[i] != b.samples[i]) {
        System.out.println("diff sample " + i + ": " + a.samples[i] + " " + b.samples[i]);
        break;
      }
    }
  }