From 5d83c1356c80c4a7254361955a0c4fe614451f29 Mon Sep 17 00:00:00 2001
From: Martmists <martmists@gmail.com>
Date: Wed, 28 Jul 2021 22:34:00 +0200
Subject: [PATCH] NoiseSharpening

---
 CMakeLists.txt                |  1 +
 src/utils/NoiseSharpening.cpp | 56 +++++++++++++++++++++++++++++++++++
 src/utils/NoiseSharpening.h   | 26 ++++++++++++++++
 3 files changed, 83 insertions(+)
 create mode 100644 src/utils/NoiseSharpening.cpp
 create mode 100644 src/utils/NoiseSharpening.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index d3fb69c..e3be1a8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,6 +36,7 @@ set(FILES
         src/utils/IIR_NOrder_BW_BP.cpp
         src/utils/IIR_NOrder_BW_LH.cpp
         src/utils/MultiBiquad.cpp
+        src/utils/NoiseSharpening.cpp
         src/utils/PassFilter.cpp
         src/utils/PolesFilter.cpp
         src/utils/TimeConstDelay.cpp
diff --git a/src/utils/NoiseSharpening.cpp b/src/utils/NoiseSharpening.cpp
new file mode 100644
index 0000000..95b8da4
--- /dev/null
+++ b/src/utils/NoiseSharpening.cpp
@@ -0,0 +1,56 @@
+//
+// Created by mart on 7/28/21.
+//
+
+#include "NoiseSharpening.h"
+#include "../constants.h"
+
+NoiseSharpening::NoiseSharpening() {
+    this->samplerate = DEFAULT_SAMPLERATE;
+    this->gain = 0.f;
+    Reset();
+}
+
+void NoiseSharpening::Process(float *buffer, uint32_t size) {
+    for (int i = 0; i < size; i++) {
+        float sampleLeft = buffer[i*2];
+        float sampleRight = buffer[i*2+1];
+        float prevLeft = this->in[0];
+        float prevRight = this->in[1];
+        this->in[0] = sampleLeft;
+        this->in[1] = sampleRight;
+        float diffLeft = (sampleLeft - prevLeft) * this->gain;
+        float diffRight = (sampleRight - prevRight) * this->gain;
+
+        float sampleLeftIn = sampleLeft + diffLeft;
+        float sampleRightIn = sampleRight + diffRight;
+
+        float hist = (sampleLeftIn) * this->filters[0].b1;
+        float left = this->filters[0].prevSample + (sampleLeftIn) * this->filters[0].b0;
+        this->filters[0].prevSample = (sampleLeftIn) * this->filters[0].a1 + hist;
+
+        hist = (sampleRightIn) * this->filters[1].b1;
+        float right = this->filters[1].prevSample + (sampleRightIn) * this->filters[1].b0;
+        this->filters[1].prevSample = (sampleRightIn) * this->filters[1].a1 + hist;
+
+        buffer[i*2] = left;
+        buffer[i*2+1] = right;
+    }
+}
+
+void NoiseSharpening::Reset() {
+    for (int i = 0; i < 2; i++) {
+        this->filters[i].setLPF_BW(this->samplerate / 2.f - 1000.f, this->samplerate);
+        this->filters[i].Mute();
+        this->in[i] = 0.f;
+    }
+}
+
+void NoiseSharpening::SetGain(float gain) {
+    this->gain = gain;
+}
+
+void NoiseSharpening::SetSamplingRate(uint32_t samplerate) {
+    this->samplerate = samplerate;
+    Reset();
+}
diff --git a/src/utils/NoiseSharpening.h b/src/utils/NoiseSharpening.h
new file mode 100644
index 0000000..e7d21d4
--- /dev/null
+++ b/src/utils/NoiseSharpening.h
@@ -0,0 +1,26 @@
+//
+// Created by mart on 7/28/21.
+//
+
+#pragma once
+
+
+#include "IIR_1st.h"
+
+class NoiseSharpening {
+public:
+    NoiseSharpening();
+
+    void Process(float* buffer, uint32_t size);
+    void Reset();
+    void SetGain(float gain);
+    void SetSamplingRate(uint32_t samplerate);
+
+    IIR_1st filters[2];
+    float in[2];
+    int32_t samplerate;
+    float gain;
+};
+
+
+