1 /* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ANDROID_AUDIO_RESAMPLER_SINC_H 18 #define ANDROID_AUDIO_RESAMPLER_SINC_H 19 20 #include <stdint.h> 21 #include <sys/types.h> 22 #include <cutils/log.h> 23 24 #include "AudioResampler.h" 25 26 namespace android { 27 28 29 typedef const int32_t * (*readCoefficientsFn)(bool upDownSample); 30 typedef int32_t (*readResampleFirNumCoeffFn)(); 31 typedef int32_t (*readResampleFirLerpIntBitsFn)(); 32 33 // ---------------------------------------------------------------------------- 34 35 class AudioResamplerSinc : public AudioResampler { 36 public: 37 AudioResamplerSinc(int inChannelCount, int32_t sampleRate, 38 src_quality quality = HIGH_QUALITY); 39 40 virtual ~AudioResamplerSinc(); 41 42 virtual size_t resample(int32_t* out, size_t outFrameCount, 43 AudioBufferProvider* provider); 44 private: 45 void init(); 46 47 virtual void setVolume(float left, float right); 48 49 template<int CHANNELS> 50 size_t resample(int32_t* out, size_t outFrameCount, 51 AudioBufferProvider* provider); 52 53 template<int CHANNELS> 54 inline void filterCoefficient( 55 int32_t* out, uint32_t phase, const int16_t *samples, uint32_t vRL); 56 57 template<int CHANNELS> 58 inline void interpolate( 59 int32_t& l, int32_t& r, 60 const int32_t* coefs, size_t offset, 61 int32_t lerp, const int16_t* samples); 62 63 template<int CHANNELS> 64 inline void read(int16_t*& impulse, uint32_t& phaseFraction, 65 const int16_t* in, size_t inputIndex); 66 67 int16_t *mState; 68 int16_t *mImpulse; 69 int16_t *mRingFull; 70 int32_t mVolumeSIMD[2]; 71 72 const int32_t * mFirCoefs; 73 static const uint32_t mFirCoefsDown[]; 74 static const uint32_t mFirCoefsUp[]; 75 76 // ---------------------------------------------------------------------------- 77 static const int32_t RESAMPLE_FIR_NUM_COEF = 8; 78 static const int32_t RESAMPLE_FIR_LERP_INT_BITS = 7; 79 80 struct Constants { 81 int coefsBits; 82 int cShift; 83 uint32_t cMask; 84 int pShift; 85 uint32_t pMask; 86 // number of zero-crossing on each side 87 unsigned int halfNumCoefs; 88 }; 89 90 static Constants highQualityConstants; 91 static Constants veryHighQualityConstants; 92 const Constants *mConstants; // points to appropriate set of coefficient parameters 93 94 static void init_routine(); 95 }; 96 97 // ---------------------------------------------------------------------------- 98 } // namespace android 99 100 #endif /*ANDROID_AUDIO_RESAMPLER_SINC_H*/ 101