diff --git a/inference/inferPreprocess.hpp b/inference/inferPreprocess.hpp
index febea2f..4c651b2 100644
--- a/inference/inferPreprocess.hpp
+++ b/inference/inferPreprocess.hpp
@@ -26,3 +26,38 @@ private:
 	double* rf0 = nullptr;
 	int64_t f0Len = 0;
 };
+
+void F0PreProcess::InterPf0(int64_t len)
+{
+	const auto xi = arange(0.0, (double)f0Len * (double)len, (double)f0Len, (double)len);
+	const auto tmp = new double[xi.size() + 1];
+	interp1(arange(0, (double)f0Len).data(), rf0, static_cast<int>(f0Len), xi.data(), (int)xi.size(), tmp);
+	for (size_t i = 0; i < xi.size(); i++)
+		if (isnan(tmp[i]))
+			tmp[i] = 0.0;
+	delete[] rf0;
+    rf0 = nullptr;
+	rf0 = tmp;
+	f0Len = (int64_t)xi.size();
+}
+
+long long* F0PreProcess::f0Log()
+{
+	const auto tmp = new long long[f0Len];
+	const auto f0_mel = new double[f0Len];
+	for (long long i = 0; i < f0Len; i++)
+	{
+		f0_mel[i] = 1127 * log(1.0 + rf0[i] / 700.0);
+		if (f0_mel[i] > 0.0)
+			f0_mel[i] = (f0_mel[i] - f0_mel_min) * (f0_bin - 2.0) / (f0_mel_max - f0_mel_min) + 1.0;
+		if (f0_mel[i] < 1.0)
+			f0_mel[i] = 1;
+		if (f0_mel[i] > f0_bin - 1)
+			f0_mel[i] = f0_bin - 1;
+		tmp[i] = (long long)round(f0_mel[i]);
+	}
+	delete[] f0_mel;
+	delete[] rf0;
+    rf0 = nullptr;
+	return tmp;
+}