public function CalculateReplayGain() {
    if (isset($this->info['replay_gain'])) {
      if (!isset($this->info['replay_gain']['reference_volume'])) {
        $this->info['replay_gain']['reference_volume'] = 89.0;
      }
      if (isset($this->info['replay_gain']['track']['adjustment'])) {
        $this->info['replay_gain']['track']['volume'] = $this->info['replay_gain']['reference_volume'] - $this->info['replay_gain']['track']['adjustment'];
      }
      if (isset($this->info['replay_gain']['album']['adjustment'])) {
        $this->info['replay_gain']['album']['volume'] = $this->info['replay_gain']['reference_volume'] - $this->info['replay_gain']['album']['adjustment'];
      }

      if (isset($this->info['replay_gain']['track']['peak'])) {
        $this->info['replay_gain']['track']['max_noclip_gain'] = 0 - getid3_lib::RGADamplitude2dB($this->info['replay_gain']['track']['peak']);
      }
      if (isset($this->info['replay_gain']['album']['peak'])) {
        $this->info['replay_gain']['album']['max_noclip_gain'] = 0 - getid3_lib::RGADamplitude2dB($this->info['replay_gain']['album']['peak']);
      }
    }
    return true;
  }