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Stop an overflow with large (>100dB) sample values.

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martynshaw99 2012-02-08 01:06:16 +00:00
parent 7bdac9233b
commit 5b3f3f71ea
1 changed files with 3 additions and 9 deletions
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12
src/Dither.cpp
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@ -76,13 +76,7 @@ const float Dither::SHAPED_BS[] = { 2.033f, -2.165f, 1.959f, -1.590f, 0.6149f };
// Dereference sample pointer and convert to float sample // Dereference sample pointer and convert to float sample
#define FROM_INT16(ptr) (*((short*)(ptr)) / CONVERT_DIV16) #define FROM_INT16(ptr) (*((short*)(ptr)) / CONVERT_DIV16)
#define FROM_INT24(ptr) (*(( int*)(ptr)) / CONVERT_DIV24) #define FROM_INT24(ptr) (*(( int*)(ptr)) / CONVERT_DIV24)
#define FROM_FLOAT(ptr) (*((float*)(ptr)))
// For float, we internally allow values greater than 1.0, which
// would blow up the dithering to int values. FROM_FLOAT is
// only used to dither to int, so clip here.
#define FROM_FLOAT(ptr) (*((float*)(ptr)) > 1.0 ? 1.0 : \
*((float*)(ptr)) < -1.0 ? -1.0 : \
*((float*)(ptr)))
// Promote sample to range of specified type, keep it float, though // Promote sample to range of specified type, keep it float, though
#define PROMOTE_TO_INT16(sample) ((sample) * CONVERT_DIV16) #define PROMOTE_TO_INT16(sample) ((sample) * CONVERT_DIV16)
@ -283,7 +277,7 @@ inline float Dither::TriangleDither(float sample)
// Shaped dither // Shaped dither
inline float Dither::ShapedDither(float sample) inline float Dither::ShapedDither(float sample)
{ {
// Generate triangular dither, +-1 LSB, flat psd // Generate triangular dither, +-1 LSB, flat psd
float r = DITHER_NOISE + DITHER_NOISE; float r = DITHER_NOISE + DITHER_NOISE;
// Run FIR // Run FIR
@ -298,7 +292,7 @@ inline float Dither::ShapedDither(float sample)
// Roll buffer and store last error // Roll buffer and store last error
mPhase = (mPhase + 1) & BUF_MASK; mPhase = (mPhase + 1) & BUF_MASK;
mBuffer[mPhase] = xe - lrintf(result); mBuffer[mPhase] = xe - llrintf(result);
return result; return result;
} }