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/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_AUDIO_RESAMPLER_DYN_H
#define ANDROID_AUDIO_RESAMPLER_DYN_H
#include <stdint.h>
#include <sys/types.h>
#include <cutils/log.h>
#include "AudioResampler.h"
namespace android {
class AudioResamplerDyn: public AudioResampler {
public:
AudioResamplerDyn(int bitDepth, int inChannelCount, int32_t sampleRate,
src_quality quality);
virtual ~AudioResamplerDyn();
virtual void init();
virtual void setSampleRate(int32_t inSampleRate);
virtual void setVolume(int16_t left, int16_t right);
virtual void resample(int32_t* out, size_t outFrameCount,
AudioBufferProvider* provider);
private:
class Constants { // stores the filter constants.
public:
Constants() :
mL(0), mShift(0), mHalfNumCoefs(0), mFirCoefsS16(NULL)
{}
void set(int L, int halfNumCoefs,
int inSampleRate, int outSampleRate);
inline void setBuf(int16_t* buf) {
mFirCoefsS16 = buf;
}
inline void setBuf(int32_t* buf) {
mFirCoefsS32 = buf;
}
int mL; // interpolation phases in the filter.
int mShift; // right shift to get polyphase index
unsigned int mHalfNumCoefs; // filter half #coefs
union { // polyphase filter bank
const int16_t* mFirCoefsS16;
const int32_t* mFirCoefsS32;
};
};
// Input buffer management for a given input type TI, now (int16_t)
// Is agnostic of the actual type, can work with int32_t and float.
template<typename TI>
class InBuffer {
public:
InBuffer();
~InBuffer();
void init();
void resize(int CHANNELS, int halfNumCoefs);
// used for direct management of the mImpulse pointer
inline TI* getImpulse() {
return mImpulse;
}
inline void setImpulse(TI *impulse) {
mImpulse = impulse;
}
template<int CHANNELS>
inline void readAgain(TI*& impulse, const int halfNumCoefs,
const TI* const in, const size_t inputIndex);
template<int CHANNELS>
inline void readAdvance(TI*& impulse, const int halfNumCoefs,
const TI* const in, const size_t inputIndex);
private:
// tuning parameter guidelines: 2 <= multiple <= 8
static const int kStateSizeMultipleOfFilterLength = 4;
TI* mState; // base pointer for the input buffer storage
TI* mImpulse; // current location of the impulse response (centered)
TI* mRingFull; // mState <= mImpulse < mRingFull
// in general, mRingFull = mState + mStateSize - halfNumCoefs*CHANNELS.
size_t mStateSize; // in units of TI.
};
template<int CHANNELS, bool LOCKED, int STRIDE, typename TC>
void resample(int32_t* out, size_t outFrameCount,
const TC* const coefs, AudioBufferProvider* provider);
template<typename T>
void createKaiserFir(Constants &c, double stopBandAtten,
int inSampleRate, int outSampleRate, double tbwCheat);
InBuffer<int16_t> mInBuffer;
Constants mConstants; // current set of coefficient parameters
int32_t __attribute__ ((aligned (8))) mVolumeSimd[2];
int32_t mResampleType; // contains the resample type.
int32_t mFilterSampleRate; // designed sample rate for the filter
void* mCoefBuffer; // if a filter is created, this is not null
};
// ----------------------------------------------------------------------------
}; // namespace android
#endif /*ANDROID_AUDIO_RESAMPLER_DYN_H*/
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