Initial community commit

Src/external_dependencies/openmpt-trunk/soundlib/SampleNormalize.h

@@ -0,0 +1,192 @@
+/*
+ * SampleNormalize.h
+ * -----------------
+ * Purpose: Functions for normalizing samples.
+ * Notes  : (currently none)
+ * Authors: OpenMPT Devs
+ * The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
+ */
+
+
+#pragma once
+
+#include "openmpt/all/BuildSettings.hpp"
+
+
+OPENMPT_NAMESPACE_BEGIN
+
+
+namespace SC
+{  // SC = _S_ample_C_onversion
+
+
+
+template <typename Tsample>
+struct Normalize;
+
+template <>
+struct Normalize<int32>
+{
+	typedef int32 input_t;
+	typedef int32 output_t;
+	typedef uint32 peak_t;
+	uint32 maxVal;
+	MPT_FORCEINLINE Normalize()
+		: maxVal(0) {}
+	MPT_FORCEINLINE void FindMax(input_t val)
+	{
+		if(val < 0)
+		{
+			if(val == std::numeric_limits<int32>::min())
+			{
+				maxVal = static_cast<uint32>(-static_cast<int64>(std::numeric_limits<int32>::min()));
+				return;
+			}
+			val = -val;
+		}
+		if(static_cast<uint32>(val) > maxVal)
+		{
+			maxVal = static_cast<uint32>(val);
+		}
+	}
+	MPT_FORCEINLINE bool IsSilent() const
+	{
+		return maxVal == 0;
+	}
+	MPT_FORCEINLINE output_t operator()(input_t val)
+	{
+		return Util::muldivrfloor(val, static_cast<uint32>(1) << 31, maxVal);
+	}
+	MPT_FORCEINLINE peak_t GetSrcPeak() const
+	{
+		return maxVal;
+	}
+};
+
+template <>
+struct Normalize<float32>
+{
+	typedef float32 input_t;
+	typedef float32 output_t;
+	typedef float32 peak_t;
+	float maxVal;
+	float maxValInv;
+	MPT_FORCEINLINE Normalize()
+		: maxVal(0.0f), maxValInv(1.0f) {}
+	MPT_FORCEINLINE void FindMax(input_t val)
+	{
+		float absval = std::fabs(val);
+		if(absval > maxVal)
+		{
+			maxVal = absval;
+		}
+	}
+	MPT_FORCEINLINE bool IsSilent()
+	{
+		if(maxVal == 0.0f)
+		{
+			maxValInv = 1.0f;
+			return true;
+		} else
+		{
+			maxValInv = 1.0f / maxVal;
+			return false;
+		}
+	}
+	MPT_FORCEINLINE output_t operator()(input_t val)
+	{
+		return val * maxValInv;
+	}
+	MPT_FORCEINLINE peak_t GetSrcPeak() const
+	{
+		return maxVal;
+	}
+};
+
+template <>
+struct Normalize<float64>
+{
+	typedef float64 input_t;
+	typedef float64 output_t;
+	typedef float64 peak_t;
+	double maxVal;
+	double maxValInv;
+	MPT_FORCEINLINE Normalize()
+		: maxVal(0.0), maxValInv(1.0) {}
+	MPT_FORCEINLINE void FindMax(input_t val)
+	{
+		double absval = std::fabs(val);
+		if(absval > maxVal)
+		{
+			maxVal = absval;
+		}
+	}
+	MPT_FORCEINLINE bool IsSilent()
+	{
+		if(maxVal == 0.0)
+		{
+			maxValInv = 1.0;
+			return true;
+		} else
+		{
+			maxValInv = 1.0 / maxVal;
+			return false;
+		}
+	}
+	MPT_FORCEINLINE output_t operator()(input_t val)
+	{
+		return val * maxValInv;
+	}
+	MPT_FORCEINLINE peak_t GetSrcPeak() const
+	{
+		return maxVal;
+	}
+};
+
+
+// Reads sample data with Func1, then normalizes the sample data, and then converts it with Func2.
+// Func1::output_t and Func2::input_t must be identical.
+// Func1 can also be the identity decode (DecodeIdentity<T>).
+// Func2 can also be the identity conversion (Convert<T,T>).
+template <typename Func2, typename Func1>
+struct NormalizationChain
+{
+	typedef typename Func1::input_t input_t;
+	typedef typename Func1::output_t normalize_t;
+	typedef typename Normalize<normalize_t>::peak_t peak_t;
+	typedef typename Func2::output_t output_t;
+	static constexpr std::size_t input_inc = Func1::input_inc;
+	Func1 func1;
+	Normalize<normalize_t> normalize;
+	Func2 func2;
+	MPT_FORCEINLINE void FindMax(const input_t *inBuf)
+	{
+		normalize.FindMax(func1(inBuf));
+	}
+	MPT_FORCEINLINE bool IsSilent()
+	{
+		return normalize.IsSilent();
+	}
+	MPT_FORCEINLINE output_t operator()(const input_t *inBuf)
+	{
+		return func2(normalize(func1(inBuf)));
+	}
+	MPT_FORCEINLINE peak_t GetSrcPeak() const
+	{
+		return normalize.GetSrcPeak();
+	}
+	MPT_FORCEINLINE NormalizationChain(Func2 f2 = Func2(), Func1 f1 = Func1())
+		: func1(f1)
+		, func2(f2)
+	{
+		return;
+	}
+};
+
+
+
+}  // namespace SC
+
+
+
+OPENMPT_NAMESPACE_END