From b5b1f69d223f716581282c43f2fabbd5a47daf43 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=BCrgen=20Hock?= <juergen.hock@jurihock.de>
Date: Mon, 11 Dec 2023 18:34:54 +0100
Subject: [PATCH] Reset vocoder phase buffer on pitch shifting factor change
 #45

---
 cpp/StftPitchShift/StftPitchShiftCore.h | 1 +
 cpp/StftPitchShift/Vocoder.h            | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/cpp/StftPitchShift/StftPitchShiftCore.h b/cpp/StftPitchShift/StftPitchShiftCore.h
index 2105775..144ac5f 100755
--- a/cpp/StftPitchShift/StftPitchShiftCore.h
+++ b/cpp/StftPitchShift/StftPitchShiftCore.h
@@ -78,6 +78,7 @@ namespace stftpitchshift
     void factors(const std::vector<double>& factors)
     {
       pitcher.factors(factors);
+      vocoder.reset(); // #45
     }
 
     double quefrency() const
diff --git a/cpp/StftPitchShift/Vocoder.h b/cpp/StftPitchShift/Vocoder.h
index 438bff9..b0e2871 100755
--- a/cpp/StftPitchShift/Vocoder.h
+++ b/cpp/StftPitchShift/Vocoder.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <algorithm>
 #include <cassert>
 #include <cmath>
 #include <complex>
@@ -45,6 +46,12 @@ namespace stftpitchshift
       }
     }
 
+    void reset()
+    {
+      // zero decode phase buffer according to #45
+      std::fill(decode_phase_buffer.begin(), decode_phase_buffer.end(), 0);
+    }
+
     void encode(const std::span<std::complex<T>> dft)
     {
       assert(dft.size() == encode_phase_buffer.size());