Duck filter

demos/megademo/radiogaga.cpp

@@ -33,6 +33,7 @@ freely, subject to the following restrictions:
 #include "soloud.h"
 #include "soloud_speech.h"
 #include "soloud_wav.h"
+#include "soloud_duckfilter.h"
 
 namespace radiogaga
 {
@@ -50,6 +51,8 @@ namespace radiogaga
 	SoLoud::handle gSpeechqueuehandle;
 	SoLoud::handle gIntrohandle;
 
+	SoLoud::DuckFilter gDuckFilter;
+
 	const char *phrase[19] =
 	{
 		"............................",
@@ -78,7 +81,7 @@ namespace radiogaga
 		gSoloud.init();
 		gSoloud.setVisualizationEnable(1);
 
-		gSoloud.play(gSpeechBus, 0.5f);
+		SoLoud::handle speechBusHandle = gSoloud.play(gSpeechBus, 0.5f);
 
 		gSoloud.play(gMusicBus);
 
@@ -113,6 +116,9 @@ namespace radiogaga
 		gSpeechBus.setVisualizationEnable(1);
 		gMusicBus.setVisualizationEnable(1);
 
+		gDuckFilter.setParams(&gSoloud, speechBusHandle);
+		gMusicBus.setFilter(0, &gDuckFilter);
+
 		gIntro.setText("Eat, Sleep, Rave, Repeat");
 		gIntro.setLooping(true);
 		gIntro.setLoopPoint(1.45f);

include/soloud_bus.h

@@ -33,10 +33,11 @@ namespace SoLoud
 
 	class BusInstance : public AudioSourceInstance
 	{
+	public:
 		Bus *mParent;
 		unsigned int mScratchSize;
 		AlignedFloatBuffer mScratch;
-	public:
+
 		// Approximate volume for channels.
 		float mVisualizationChannelVolume[MAX_CHANNELS];
 		// Mono-mixed wave data for visualization and for visualization FFT input

include/soloud_duckfilter.h

@@ -0,0 +1,71 @@
+/*
+SoLoud audio engine
+Copyright (c) 2013-2021 Jari Komppa
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+   1. The origin of this software must not be misrepresented; you must not
+   claim that you wrote the original software. If you use this software
+   in a product, an acknowledgment in the product documentation would be
+   appreciated but is not required.
+
+   2. Altered source versions must be plainly marked as such, and must not be
+   misrepresented as being the original software.
+
+   3. This notice may not be removed or altered from any source
+   distribution.
+*/
+
+#ifndef SOLOUD_DUCKFILTER_H
+#define SOLOUD_DUCKFILTER_H
+
+#include "soloud.h"
+
+namespace SoLoud
+{
+	class DuckFilter;
+
+	class DuckFilterInstance : public FilterInstance
+	{
+		handle mListenTo;
+		Soloud* mSoloud;
+		float mCurrentLevel;
+	public:
+		virtual void filter(float *aBuffer, unsigned int aSamples, unsigned int aBufferSize, unsigned int aChannels, float aSamplerate, time aTime);
+		virtual ~DuckFilterInstance();
+		DuckFilterInstance(DuckFilter *aParent);
+	};
+
+	class DuckFilter : public Filter
+	{
+	public:
+		enum FILTERATTRIBUTE
+		{
+			WET = 0,
+			ONRAMP,
+			OFFRAMP,
+			LEVEL
+		};
+		Soloud* mSoloud;
+		float mOnRamp;
+		float mOffRamp;
+		float mLevel;
+		handle mListenTo;
+		virtual int getParamCount();
+		virtual const char* getParamName(unsigned int aParamIndex);
+		virtual unsigned int getParamType(unsigned int aParamIndex);
+		virtual float getParamMax(unsigned int aParamIndex);
+		virtual float getParamMin(unsigned int aParamIndex);
+		virtual FilterInstance *createInstance();
+		DuckFilter();
+		result setParams(Soloud* aSoloud, handle aListenTo, float aOnRamp = 0.1f, float aOffRamp = 0.5f, float aLevel = 0.1f);
+	};
+}
+
+#endif

src/filter/soloud_duckfilter.cpp

@@ -0,0 +1,147 @@
+/*
+SoLoud audio engine
+Copyright (c) 2013-2021 Jari Komppa
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+   1. The origin of this software must not be misrepresented; you must not
+   claim that you wrote the original software. If you use this software
+   in a product, an acknowledgment in the product documentation would be
+   appreciated but is not required.
+
+   2. Altered source versions must be plainly marked as such, and must not be
+   misrepresented as being the original software.
+
+   3. This notice may not be removed or altered from any source
+   distribution.
+*/
+
+#include "soloud.h"
+#include "soloud_duckfilter.h"
+
+namespace SoLoud
+{
+	DuckFilterInstance::DuckFilterInstance(DuckFilter *aParent)
+	{
+		initParams(4);
+		mParam[DuckFilter::ONRAMP] = aParent->mOnRamp;
+		mParam[DuckFilter::OFFRAMP] = aParent->mOffRamp;
+		mParam[DuckFilter::LEVEL] = aParent->mLevel;
+		mListenTo = aParent->mListenTo;
+		mSoloud = aParent->mSoloud;
+		mCurrentLevel = 1;
+	}
+
+	void DuckFilterInstance::filter(float *aBuffer, unsigned int aSamples, unsigned int aBufferSize, unsigned int aChannels, float aSamplerate, double aTime)
+	{
+		updateParams(aTime);
+		float onramp_step = 1;
+		if (mParam[DuckFilter::ONRAMP] > 0.01)
+			onramp_step = (1.0f - mParam[DuckFilter::LEVEL]) / (mParam[DuckFilter::ONRAMP] * aSamplerate);
+		float offramp_step = 1;
+		if (mParam[DuckFilter::OFFRAMP] > 0.01)
+			offramp_step = (1.0f - mParam[DuckFilter::LEVEL]) / (mParam[DuckFilter::OFFRAMP] * aSamplerate);
+
+		int soundOn = 0;
+		if (mSoloud)
+		{
+			int voiceno = mSoloud->getVoiceFromHandle_internal(mListenTo);
+			if (voiceno != -1)
+			{
+				BusInstance* bi = (BusInstance*)mSoloud->mVoice[voiceno];
+				float v = 0;
+				for (unsigned int i = 0; i < bi->mChannels; i++)
+					v += bi->mVisualizationChannelVolume[i];
+				if (v > 0.01f)
+					soundOn = 1;
+			}
+		}
+		float level = mCurrentLevel;
+		for (unsigned int j = 0; j < aChannels; j++)
+		{
+			level = mCurrentLevel;
+			int bchofs = j * aBufferSize;
+			for (unsigned int i = 0; i < aSamples; i++)
+			{
+				if (soundOn && level > mParam[DuckFilter::LEVEL])
+					level -= onramp_step;
+				if (!soundOn && level < 1)
+					level += offramp_step;
+				if (level < mParam[DuckFilter::LEVEL]) level = mParam[DuckFilter::LEVEL];
+				if (level > 1) level = 1;
+				aBuffer[i + bchofs] += (-aBuffer[i + bchofs] + aBuffer[i + bchofs] * level) * mParam[DuckFilter::WET];
+			}
+		}
+		mCurrentLevel = level;
+	}
+
+	DuckFilterInstance::~DuckFilterInstance()
+	{
+	}
+
+	DuckFilter::DuckFilter()
+	{
+		mSoloud = 0;
+		mOnRamp = 0.1f;
+		mOffRamp = 0.5f;
+		mLevel = 0.5f;
+	}
+
+	result DuckFilter::setParams(Soloud* aSoloud, handle aListenTo, float aOnRamp, float aOffRamp, float aLevel)
+	{
+		if (aOnRamp < 0.0f || aOffRamp < 0.0f || aLevel < 0.0f || aSoloud == 0 || !aSoloud->isValidVoiceHandle(aListenTo))
+			return INVALID_PARAMETER;
+
+		mListenTo = aListenTo;
+		mOnRamp = aOnRamp;
+		mOffRamp = aOffRamp;
+		mLevel = aLevel;
+		mSoloud = aSoloud;
+
+		return 0;
+	}
+
+	int DuckFilter::getParamCount()
+	{
+		return 4;
+	}
+
+	const char* DuckFilter::getParamName(unsigned int aParamIndex)
+	{
+		if (aParamIndex > 3)
+			return 0;
+		const char *names[4] = {
+			"Wet",
+			"OnRamp",
+			"OffRamp",
+			"Level"
+		};
+		return names[aParamIndex];
+	}
+
+	unsigned int DuckFilter::getParamType(unsigned int aParamIndex)
+	{
+		return FLOAT_PARAM;
+	}
+
+	float DuckFilter::getParamMax(unsigned int aParamIndex)
+	{
+		return 1;
+	}
+
+	float DuckFilter::getParamMin(unsigned int aParamIndex)
+	{
+		return 0;
+	}
+
+	FilterInstance *DuckFilter::createInstance()
+	{
+		return new DuckFilterInstance(this);
+	}
+}