message: 0 Hz is now accepted as the lower frequency limit for the MFCC filterbank.
diff: @@ -62,8 +62,8 @@ bool MfccMelFilterbank::Initialize(int input_length,
  return false;
  }
  - if (lower_frequency_limit <= 0) {
  - LOG(ERROR) << "Lower frequency limit must be positive.";
  + if (lower_frequency_limit < 0) {
  + LOG(ERROR) << "Lower frequency limit must be nonnegative.";
  return false;
  }
  