latest SDK

pfc/audio_sample.cpp

@@ -0,0 +1,73 @@
+#include "pfc.h"
+
+namespace pfc {
+    audio_sample audio_math::decodeFloat24ptr(const void * sourcePtr) {
+		PFC_STATIC_ASSERT(pfc::byte_order_is_little_endian);
+		union {
+			uint8_t bytes[4];
+			float v;
+		} u;
+		const uint8_t * s = reinterpret_cast<const uint8_t*>(sourcePtr);
+		u.bytes[0] = 0;
+		u.bytes[1] = s[0];
+		u.bytes[2] = s[1];
+		u.bytes[3] = s[2];
+		return u.v;
+	}
+	audio_sample audio_math::decodeFloat24ptrbs(const void * sourcePtr) {
+		PFC_STATIC_ASSERT(pfc::byte_order_is_little_endian);
+		union {
+			uint8_t bytes[4];
+			float v;
+		} u;
+		const uint8_t * s = reinterpret_cast<const uint8_t*>(sourcePtr);
+		u.bytes[0] = 0;
+		u.bytes[1] = s[2];
+		u.bytes[2] = s[1];
+		u.bytes[3] = s[0];
+		return u.v;
+	}
+
+	audio_sample audio_math::decodeFloat16(uint16_t source) {
+		const unsigned fractionBits = 10;
+		const unsigned widthBits = 16;
+		typedef uint16_t source_t;
+
+	/*	typedef uint64_t out_t; typedef double retval_t;
+		enum { 
+			outExponent = 11, 
+			outFraction = 52, 
+			outExponentShift = (1 << (outExponent-1))-1 
+		};*/
+
+		typedef uint32_t out_t; typedef float retval_t;
+		enum { 
+			outExponent = 8, 
+			outFraction = 23, 
+			outExponentShift = (1 << (outExponent-1))-1 
+		};
+
+		const unsigned exponentBits = widthBits - fractionBits - 1;
+		// 1 bit sign | exponent | fraction
+		source_t fraction = source & (((source_t)1 << fractionBits)-1);
+		source >>= fractionBits;
+		int exponent = (int)( source & (((source_t)1 << exponentBits)-1) ) - (int)((1 << (exponentBits-1))-1);
+		source >>= exponentBits;
+
+		if (outExponent + outExponentShift <= 0) return 0;
+
+		out_t output = (out_t)( source&1 );
+		output <<= outExponent;
+		output |= (unsigned) (exponent + outExponentShift) & ( (1<<outExponent) - 1 );
+		output <<= outFraction;
+		int shift = (int) outFraction - (int) fractionBits;
+		if (shift < 0) output |= (out_t) (fraction >> -shift);
+		else output |= (out_t) (fraction << shift);
+		return *(retval_t*)&output / pfc::audio_math::float16scale;
+	}
+
+	unsigned audio_math::bitrate_kbps(uint64_t fileSize, double duration) {
+		if (fileSize > 0 && duration > 0) return (unsigned)floor((double)fileSize * 8 / (duration * 1000) + 0.5);
+		return 0;
+	}
+}