From 5693da0f42ca92ad45166999988e250ebf494a00 Mon Sep 17 00:00:00 2001
From: Vektor <whiteman.chr@hotmail.com>
Date: Tue, 15 Aug 2023 16:26:26 +0200
Subject: [PATCH] readd normalization

---
 examples/devicetests.cpp |  1 +
 include/ISoundInput.h    |  3 +++
 src/CSoundInput.cpp      | 41 ++++++++++++++++++++++++++++++++++++++++
 src/CSoundInput.h        | 10 +++++++++-
 4 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/examples/devicetests.cpp b/examples/devicetests.cpp
index 81c2b5a..74c975a 100644
--- a/examples/devicetests.cpp
+++ b/examples/devicetests.cpp
@@ -63,6 +63,7 @@ int main()
 	soundInput->SelectDeviceByUID(nullptr);
 	soundInput->SetStreamEnabled(true);
 	soundInput->SetNoiseSuppressionEnabled(true);
+	soundInput->SetNormalizatonEnabled(true);
 	std::cout << soundInput->GetCurrentDeviceUID() << std::endl;
 
 	for(;;)
diff --git a/include/ISoundInput.h b/include/ISoundInput.h
index 96409df..97f7b35 100644
--- a/include/ISoundInput.h
+++ b/include/ISoundInput.h
@@ -33,4 +33,7 @@ class ISoundInput
 	virtual void SetStreamEnabled(bool enabled) = 0;
 	virtual void SetNoiseSuppressionEnabled(bool enabled) = 0;
 	[[nodiscard]] virtual bool IsNoiseSuppressionEnabled() const = 0;
+
+	virtual void SetNormalizatonEnabled(bool enabled) = 0;
+	[[nodiscard]] virtual bool IsNormalizationEnabled() const = 0;
 };
\ No newline at end of file
diff --git a/src/CSoundInput.cpp b/src/CSoundInput.cpp
index 8f85422..ea915e9 100644
--- a/src/CSoundInput.cpp
+++ b/src/CSoundInput.cpp
@@ -242,6 +242,44 @@ void CSoundInput::NoiseSuppressionProcess(void* buffer, DWORD length)
 	}
 }
 
+void CSoundInput::SetNormalizatonEnabled(bool enabled)
+{
+	normalizationEnabled = enabled;
+}
+
+bool CSoundInput::IsNormalizationEnabled() const
+{
+	return normalizationEnabled;
+}
+
+void CSoundInput::Normalize(short* buffer, DWORD length)
+{
+	if(normalizationEnabled)
+	{
+		short maxFrame = 0;
+		for (int i = 0; i < length; ++i)
+		{
+			short s = abs(buffer[i]);
+			if (s > maxFrame)
+				maxFrame = s;
+		}
+
+		if (normalizeMax == 0.f || maxFrame > normalizeMax || normalizeMax / maxFrame < 0.5)
+			normalizeMax = maxFrame;
+		else
+			normalizeMax = (normalizeMax * (NORMALIZE_FRAME_COUNT - 1) + maxFrame) / NORMALIZE_FRAME_COUNT;
+
+		if (normalizeMax <= 1.f)
+			return;
+
+		float gain = MAXSHORT / normalizeMax / 2;
+		gain = std::fmin<float, float>(gain, 10);
+
+		for (int i = 0; i < length; ++i)
+			buffer[i] *= gain;
+	}
+}
+
 void CSoundInput::SoundFrameCaptured(HRECORD handle, const void* buffer, DWORD length)
 {
 	// Create new buffer on stack because buffer was marked as const in API
@@ -250,6 +288,9 @@ void CSoundInput::SoundFrameCaptured(HRECORD handle, const void* buffer, DWORD l
 	// Apply noise suppression
 	NoiseSuppressionProcess(writableBuffer, FRAME_SIZE_SAMPLES);
 
+	// Apply normalization
+	Normalize(writableBuffer, FRAME_SIZE_SAMPLES);
+
 	// Get current microphone noise level
 	const DWORD currentMicLevel = BASS_ChannelGetLevel(handle);
 
diff --git a/src/CSoundInput.h b/src/CSoundInput.h
index 7ac502f..69311ce 100644
--- a/src/CSoundInput.h
+++ b/src/CSoundInput.h
@@ -11,6 +11,7 @@ class CSoundInput : public ISoundInput
 {
 	static constexpr int RNNoiseFrameSize = 480;
 	static constexpr float MaxShortFloatValue = 32768.0f;
+	static constexpr int NORMALIZE_FRAME_COUNT = 20;
 
 	HRECORD recordChannel = 0;
 	COpusEncoder* encoder = nullptr;
@@ -20,6 +21,9 @@ class CSoundInput : public ISoundInput
 	float micLevel = 0;
 	bool noiseSuppressionEnabled = false;
 
+	bool normalizationEnabled = false;
+	float normalizeMax = 0.f;
+
 	HFX VolumeChangeFX;
 	DenoiseState* denoiser;
 
@@ -56,8 +60,12 @@ class CSoundInput : public ISoundInput
 	void RegisterCallback(OnVoiceCallback callback) override;
 
 	void SetNoiseSuppressionEnabled(bool enabled) override;
-	void NoiseSuppressionProcess(void* buffer, DWORD length);
 	[[nodiscard]] bool IsNoiseSuppressionEnabled() const override;
+	void NoiseSuppressionProcess(void* buffer, DWORD length);
+
+	void SetNormalizatonEnabled(bool enabled) override;
+	[[nodiscard]] bool IsNormalizationEnabled() const override;
+	void Normalize(short* buffer, DWORD length);
 
 	void SoundFrameCaptured(HRECORD handle, const void* buffer, DWORD length);
 	static BOOL OnSoundFrame(HRECORD handle, const void* buffer, DWORD length, void* user);