Initial community commit

Src/Winamp/conversions.cpp

@@ -0,0 +1,114 @@
+#include "main.h"
+#include <math.h>
+#pragma intrinsic(fabs)
+
+/*
+#ifndef _WIN64
+__inline static int lrint(double flt) 
+{
+	int intgr;
+
+	_asm
+	{
+		fld flt
+		fistp intgr
+	}
+
+	return intgr;
+} 
+#else
+__inline static int lrint(double flt) 
+{
+	return (int)flt;
+} 
+#endif
+*/
+
+#define PA_CLIP_( val, min, max )\
+    { val = ((val) < (min)) ? (min) : (((val) > (max)) ? (max) : (val)); }
+
+ void Float32_To_Int16_Clip(
+    void *destinationBuffer, signed int destinationStride,
+    void *sourceBuffer, signed int sourceStride,
+    unsigned int count)
+{
+    float *src = (float*)sourceBuffer;
+    signed short *dest =  (signed short*)destinationBuffer;
+
+    while( count-- )
+    {
+        long samp = lrint((*src * (32768.0)));
+
+        PA_CLIP_( samp, -0x8000, 0x7FFF );
+        *dest = (signed short) samp;
+
+        src += sourceStride;
+        dest += destinationStride;
+    }
+}
+
+inline static double clip(double x, double a, double b)
+{
+   double x1 = fabs (x-a);
+   double x2 = fabs (x-b);
+   x = x1 + (a+b);
+   x -= x2;
+   x *= 0.5;
+	 return x;
+}
+
+/*
+benski> this might be faster than what the compiler spits out for the above function,
+but we should benchmark
+inline static double clip(double x, double a, double b)
+{
+	const double zero_point_five = 0.5;
+	__asm 
+	{
+		fld	x
+		fld a
+		fld b
+
+		fld st(2)
+		fsub st(0),st(2) // x-b
+		fabs
+		fadd st(0),st(2) 
+		fadd st(0),st(1)
+
+		fld st(3)
+		fsub st(0), st(2)
+		fabs
+		fsubp st(1), st(0)
+		fmul zero_point_five
+
+		ffree st(4)
+		ffree st(3)
+		ffree st(2)
+		ffree st(1)
+	}
+}
+*/
+
+
+void Float32_To_Int24_Clip(
+    void *destinationBuffer, signed int destinationStride,
+    void *sourceBuffer, signed int sourceStride,
+    unsigned int count)
+{
+    float *src = (float*)sourceBuffer;
+    unsigned char *dest = (unsigned char*)destinationBuffer;
+
+    while( count-- )
+    {
+        /* convert to 32 bit and drop the low 8 bits */
+        double scaled = *src * 0x7FFFFFFF;
+        scaled=clip( scaled, -2147483648., 2147483647.  );
+        signed long temp = (signed long) scaled;
+
+        dest[0] = (unsigned char)(temp >> 8);
+        dest[1] = (unsigned char)(temp >> 16);
+        dest[2] = (unsigned char)(temp >> 24);
+        src += sourceStride;
+        dest += destinationStride * 3;
+    }
+}