added linear fade-out class

HephAudio/HeaderFiles/AudioEffects/LinearFadeOut.h

@@ -0,0 +1,93 @@
+#pragma once
+#include "HephAudioShared.h"
+#include "AudioEffect.h"
+
+/** @file */
+
+namespace HephAudio
+{
+	/**
+	 * @brief applies linear fade-out.
+	 *
+	 */
+	class LinearFadeOut : public AudioEffect
+	{
+	public:
+		using AudioEffect::Process;
+
+	protected:
+		/**
+		 * duration of the fade-out in seconds.
+		 *
+		 */
+		double duration;
+
+		/**
+		 * index of the first audio frame the effect will be applied to.
+		 *
+		 */
+		size_t startIndex;
+
+		/**
+		 * for real-time processing.
+		 *
+		 */
+		size_t currentIndex;
+
+	public:
+		/** @copydoc default_constructor */
+		LinearFadeOut();
+
+		/**
+		 * @copydoc constructor
+		 *
+		 * @param duration @copydetails duration
+		 *
+		 */
+		explicit LinearFadeOut(double duration);
+
+		/**
+		 * @copydoc constructor
+		 *
+		 * @param duration @copydetails duration
+		 * @param startIndex @copydetails startIndex
+		 *
+		 */
+		LinearFadeOut(double duration, size_t startIndex);
+
+		/** @copydoc destructor */
+		virtual ~LinearFadeOut() = default;
+
+		virtual std::string Name() const override;
+		virtual void Process(AudioBuffer& buffer, size_t startIndex, size_t frameCount) override;
+
+		/**
+		 * gets the duration in seconds.
+		 *
+		 */
+		virtual double GetDuration() const;
+
+		/**
+		 * sets the duration.
+		 *
+		 * @param duration @copydetails duration
+		 */
+		virtual void SetDuration(double duration);
+
+		/**
+		 * gets the start index.
+		 *
+		 */
+		virtual size_t GetStartIndex() const;
+
+		/**
+		 * sets the start index.
+		 *
+		 * @param startIndex @copydetails startIndex
+		 */
+		virtual void SetStartIndex(size_t startIndex);
+
+	protected:
+		virtual void ProcessST(const AudioBuffer& inputBuffer, AudioBuffer& outputBuffer, size_t startIndex, size_t frameCount) override;
+	};
+}

HephAudio/HephAudio.vcxitems

@@ -98,8 +98,10 @@
     <ClInclude Include="$(MSBuildThisFileDirectory)HeaderFiles\AudioEffects\RmsNormalizer.h" />
     <ClInclude Include="$(MSBuildThisFileDirectory)HeaderFiles\AudioEffects\Overdrive.h" />
     <ClInclude Include="$(MSBuildThisFileDirectory)HeaderFiles\AudioEffects\LinearFadeIn.h" />
+    <ClInclude Include="$(MSBuildThisFileDirectory)HeaderFiles\AudioEffects\LinearFadeOut.h" />
   </ItemGroup>
   <ItemGroup>
+    <ClCompile Include="$(MSBuildThisFileDirectory)SourceFiles\AudioEffects\LinearFadeOut.cpp" />
     <ClCompile Include="$(MSBuildThisFileDirectory)SourceFiles\AudioEffects\LinearFadeIn.cpp" />
     <ClCompile Include="$(MSBuildThisFileDirectory)SourceFiles\AudioEffects\Overdrive.cpp" />
     <ClCompile Include="$(MSBuildThisFileDirectory)SourceFiles\AudioEffects\CubicDistortion.cpp" />

HephAudio/HephAudio.vcxitems.filters

@@ -252,6 +252,7 @@
     <ClInclude Include="$(MSBuildThisFileDirectory)HeaderFiles\AudioEffects\CubicDistortion.h" />
     <ClInclude Include="$(MSBuildThisFileDirectory)HeaderFiles\AudioEffects\Overdrive.h" />
     <ClInclude Include="$(MSBuildThisFileDirectory)HeaderFiles\AudioEffects\LinearFadeIn.h" />
+    <ClInclude Include="$(MSBuildThisFileDirectory)HeaderFiles\AudioEffects\LinearFadeOut.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(MSBuildThisFileDirectory)SourceFiles\AudioProcessor.cpp">
@@ -420,5 +421,6 @@
     <ClCompile Include="$(MSBuildThisFileDirectory)SourceFiles\AudioEffects\CubicDistortion.cpp" />
     <ClCompile Include="$(MSBuildThisFileDirectory)SourceFiles\AudioEffects\Overdrive.cpp" />
     <ClCompile Include="$(MSBuildThisFileDirectory)SourceFiles\AudioEffects\LinearFadeIn.cpp" />
+    <ClCompile Include="$(MSBuildThisFileDirectory)SourceFiles\AudioEffects\LinearFadeOut.cpp" />
   </ItemGroup>
 </Project>

HephAudio/SourceFiles/AudioEffects/LinearFadeOut.cpp

@@ -0,0 +1,77 @@
+#include "AudioEffects/LinearFadeOut.h"
+#include "Exceptions/InvalidArgumentException.h"
+#include "HephMath.h"
+
+using namespace Heph;
+
+namespace HephAudio
+{
+	LinearFadeOut::LinearFadeOut() : LinearFadeOut(0.5) {}
+
+	LinearFadeOut::LinearFadeOut(double duration) : LinearFadeOut(duration, 0) {}
+
+	LinearFadeOut::LinearFadeOut(double duration, size_t startIndex) : AudioEffect(), currentIndex(0)
+	{
+		this->SetDuration(duration);
+		this->SetStartIndex(startIndex);
+	}
+
+	std::string LinearFadeOut::Name() const
+	{
+		return "Linear Fade-out";
+	}
+
+	void LinearFadeOut::Process(AudioBuffer& buffer, size_t startIndex, size_t frameCount)
+	{
+		AudioEffect::Process(buffer, startIndex, frameCount);
+		this->currentIndex += frameCount;
+	}
+
+	double LinearFadeOut::GetDuration() const
+	{
+		return this->duration;
+	}
+
+	void LinearFadeOut::SetDuration(double duration)
+	{
+		if (duration < 0)
+		{
+			HEPH_RAISE_AND_THROW_EXCEPTION(this, InvalidArgumentException(HEPH_FUNC, "duration cannot be negative."));
+		}
+
+		this->duration = duration;
+	}
+
+	size_t LinearFadeOut::GetStartIndex() const
+	{
+		return this->startIndex;
+	}
+
+	void LinearFadeOut::SetStartIndex(size_t startIndex)
+	{
+		this->startIndex = startIndex;
+	}
+
+	void LinearFadeOut::ProcessST(const AudioBuffer& inputBuffer, AudioBuffer& outputBuffer, size_t startIndex, size_t frameCount)
+	{
+		startIndex += this->currentIndex;
+		size_t endIndex = startIndex + frameCount;
+		const AudioFormatInfo& formatInfo = outputBuffer.FormatInfo();
+		const double duration_sample = formatInfo.sampleRate * this->duration;
+
+		if (endIndex > this->startIndex && startIndex < (this->startIndex + duration_sample))
+		{
+			startIndex = HEPH_MATH_MAX(startIndex, this->startIndex) - this->currentIndex;
+			endIndex = HEPH_MATH_MIN(endIndex, (duration_sample + this->startIndex)) - this->currentIndex;
+
+			for (size_t i = startIndex; i < endIndex; ++i)
+			{
+				const double factor = ((this->startIndex + duration_sample) - (i + this->currentIndex)) / duration_sample;
+				for (size_t j = 0; j < formatInfo.channelLayout.count; ++j)
+				{
+					outputBuffer[i][j] *= factor;
+				}
+			}
+		}
+	}
+}