diff options
Diffstat (limited to 'libs/audioflinger/AudioResamplerSinc.h')
| -rw-r--r-- | libs/audioflinger/AudioResamplerSinc.h | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/libs/audioflinger/AudioResamplerSinc.h b/libs/audioflinger/AudioResamplerSinc.h index 89b9577..e6cb90b 100644 --- a/libs/audioflinger/AudioResamplerSinc.h +++ b/libs/audioflinger/AudioResamplerSinc.h @@ -24,19 +24,20 @@ #include "AudioResampler.h" namespace android { + // ---------------------------------------------------------------------------- class AudioResamplerSinc : public AudioResampler { public: - AudioResamplerSinc(int bitDepth, int inChannelCount, int32_t sampleRate); + AudioResamplerSinc(int bitDepth, int inChannelCount, int32_t sampleRate); + + ~AudioResamplerSinc(); - ~AudioResamplerSinc(); - virtual void resample(int32_t* out, size_t outFrameCount, AudioBufferProvider* provider); private: void init(); - + template<int CHANNELS> void resample(int32_t* out, size_t outFrameCount, AudioBufferProvider* provider); @@ -52,12 +53,12 @@ private: template<int CHANNELS> inline void read(int16_t*& impulse, uint32_t& phaseFraction, - int16_t const* in, size_t inputIndex); + int16_t const* in, size_t inputIndex); int16_t *mState; int16_t *mImpulse; int16_t *mRingFull; - + int32_t const * mFirCoefs; static const int32_t mFirCoefsDown[]; static const int32_t mFirCoefsUp[]; @@ -67,15 +68,15 @@ private: static const int32_t RESAMPLE_FIR_LERP_INT_BITS = 4; // we have 16 coefs samples per zero-crossing - static const int coefsBits = RESAMPLE_FIR_LERP_INT_BITS; - static const int cShift = kNumPhaseBits - coefsBits; - static const uint32_t cMask = ((1<<coefsBits)-1) << cShift; + static const int coefsBits = RESAMPLE_FIR_LERP_INT_BITS; // 4 + static const int cShift = kNumPhaseBits - coefsBits; // 26 + static const uint32_t cMask = ((1<<coefsBits)-1) << cShift; // 0xf<<26 = 3c00 0000 // and we use 15 bits to interpolate between these samples // this cannot change because the mul below rely on it. static const int pLerpBits = 15; - static const int pShift = kNumPhaseBits - coefsBits - pLerpBits; - static const uint32_t pMask = ((1<<pLerpBits)-1) << pShift; + static const int pShift = kNumPhaseBits - coefsBits - pLerpBits; // 11 + static const uint32_t pMask = ((1<<pLerpBits)-1) << pShift; // 0x7fff << 11 // number of zero-crossing on each side static const unsigned int halfNumCoefs = RESAMPLE_FIR_NUM_COEF; |