itgmania212121/src/RageSoundReader_Resample_Good.cpp

/*
 * This implements audio resampling, using the method described at:
 *  http://www.dspguru.com/info/faqs/mrfaq.htm
 *
 * Each conversion ratio uses some memory, but the resulting table is
 * shared, so the memory overhead per stream is negligible.
 */
#include "global.h"
#include "RageSoundReader_Resample_Good.h"
#include "RageLog.h"
#include "RageUtil.h"
#include "RageMath.h"
#include "RageThreads.h"

#include <cmath>
#include <cstddef>
#include <numeric>

/* Filter length.  This must be a power of 2. */
#define L 8

namespace
{
	float sincf( float f )
	{
		if( f == 0 )
			return 1;
		return std::sin(f) / f;
	}

	/* Modified Bessel function I0.  From Abramowitz and Stegun "Handbook of Mathematical
	 * Functions", "Modified Bessel Functions I and K". */
	float BesselI0( float fX )
	{
		float fAbsX = std::abs( fX );
		if( fAbsX < 3.75f )
		{
			float y = fX / 3.75f;
			y *= y;
			float fRet = 1.0f+y*(+3.5156229f+y*(+3.0899424f+y*(+1.2067492f+y*(+0.2659732f+y*(+0.0360768f+y*+0.0045813f)))));
			return fRet;
		}
		else
		{
			float y = 3.75f/fAbsX;
			float fRet = (std::exp(fAbsX)/std::sqrt(fAbsX)) *
				  (+0.39894228f+y*(+0.01328592f+y*(+0.00225319f+y*(-0.00157565f+y*(0.00916281f+
				y*(-0.02057706f+y*(+0.02635537f+y*(-0.01647633f+y*+0.00392377f))))))));
			return fRet;
		}
	}

	/*
	 * Kaiser window:
	 *
	 * K(n) = I0( B*sqrt(1-(n/p)^2) )
	 *        -----------------------
	 *                 I0(B)
	 *
	 * where B is the beta parameter, p is len/2, and n is in [-len/2,+len/2].
	 */
	void ApplyKaiserWindow( float *pBuf, int iLen, float fBeta )
	{
		const float fDenom = BesselI0(fBeta);
		float p = (iLen-1)/2.0f;
		for( int n = 0; n < iLen; ++n )
		{
			float fN1 = std::abs((n-p)/p);
			float fNum = fBeta * std::sqrt( std::max(1.0f - fN1*fN1, 0.0f) );
			fNum = BesselI0( fNum );
			float fVal = fNum/fDenom;
			pBuf[n] *= fVal;
		}
	}

	void MultiplyVector( float *pStart, float *pEnd, float f )
	{
		for( ; pStart != pEnd; ++pStart )
			*pStart *= f;
	}

	void GenerateSincLowPassFilter( float *pFIR, int iWinSize, float fCutoff )
	{
		float p = (iWinSize-1)/2.0f;
		for( int n = 0; n < iWinSize; ++n )
		{
			float fN1 = (n-p);
			float fVal = sincf(2*PI*fCutoff * fN1)*(2*fCutoff);
			// printf( "n %i, %f, %f -> %f\n", n, p, fN1, fVal );
			pFIR[n] = fVal;
		}
#if 0
		float *pFIRp = pFIR+iWinSize/2;
		for(int i=-iWinSize/2;i<=iWinSize/2;i++)
		{
			float ff = sinc(2*M_PI*fCutoff * (i + 0.0))*(2*fCutoff);

			printf( "%i: %f\n", i, ff );

			pFIRp[i]=ff;
		}
		for( int i=0; i < iWinSize; i++ )
			printf( "sinc: %i: %f\n", i, pFIR[i] );
#endif
	}

	void NormalizeVector( float *pBuf, int iSize )
	{
		float fTotal = std::accumulate( &pBuf[0], &pBuf[iSize], 0.0f );
		MultiplyVector( &pBuf[0], &pBuf[iSize], 1/fTotal );
	}

	int GCD( int i1, int i2 )
	{
		return std::gcd(i1, i2);
	}
}

#if 0
void RunFIRFilter( float *pIn, float *pOut, int iInputValues, float *pFIR, int iWinSize )
{
	for( int i = 0; i < iInputValues; ++i )
	{
		float fSum = 0;
		const float *pInData = &pIn[i];
		for( int j = 0; j < iWinSize; ++j )
		{
			float in = pInData[j];
			fSum += in*pFIR[j];
			printf( "%i: in %f * %f, += %f\n", j, pInData[j], pFIR[j], in*pFIR[j] );
		}

		pOut[i] = fSum;
	}
}
#endif

template<typename T>
class AlignedBuffer
{
public:
	AlignedBuffer( int iSize )
	{
		m_iSize = iSize;
		m_pBuf = new T[m_iSize];
	}

	AlignedBuffer( const AlignedBuffer &cpy )
	{
		m_iSize = cpy.m_iSize;
		m_pBuf = new T[m_iSize];
		memcpy( m_pBuf, cpy.m_pBuf, sizeof(T)*m_iSize );
	}
	~AlignedBuffer()
	{
		delete [] m_pBuf;
	}
	operator T*() { return m_pBuf; }
	operator const T*() const { return m_pBuf; }

private:
	T& operator=( T &rhs );
	int m_iSize;
	T *m_pBuf;
};

struct PolyphaseFilter
{
	struct State
	{
		State( int iUpFactor ):
			m_fBuf( L * 2 )
		{
			m_iPolyIndex = iUpFactor-1;
			m_iFilled = 0;
			m_iBufNext = 0;
		}

		int m_iPolyIndex;
		int m_iFilled;

		/* This buffer is duplicated.  If the circular buffer is size L, the actual buffer
		 * is size L*2, and data at buf[N] is also at buf[N+L].  That way, we can access
		 * up to buf[N*2-1] without having to wrap. */
		AlignedBuffer<float> m_fBuf;
		int m_iBufNext;
	};
	friend struct State;

	PolyphaseFilter( int iUpFactor ):
		m_pPolyphase( L*iUpFactor )
	{
		m_iUpFactor = iUpFactor;
	}

	void Generate( const float *pFIR );
	int RunPolyphaseFilter( State &State, const float *pIn, int iSamplesIn, int iDownFactor,
			float *pOut, int iSamplesOut, int iSampleStride ) const;
	int GetLatency() const { return L/2; }

	int NumInputsForOutputSamples( const State &State, int iOut, int iDownFactor ) const;

private:
	AlignedBuffer<float> m_pPolyphase;
	int m_iUpFactor;
};

/*
 * Convert an FIR filter to a polyphase filter.
 *
 * pFIR is the input FIR filter, which has iL*iUpFactor values.
 * iL is the number of real samples each output sample looks at.
 * iUpFactor is the actual upsampling factor; the amount of zero-stuffing between each real sample.
 * pOutput is the 2D output polyphase filter, with iL*iL values.
 *
 * With an upsampling factor (iUpFactor) of 3, and a sinc filter length of 12 (iL*iUpFactor),
 *
 * input     first output sample (before decimation)
 * sample          second output sample
 *                     third output sample
 *
 * 0         0
 * 0         1     0
 * 1592      2     1   0
 * 0         3     2   1
 * 0         4     3   2
 * 1623      5     4   3
 * 0         6     5   4
 * 0         7     6   5
 * 1682      8     7   6
 * 0         9     8   7
 * 0         10    9   8
 * 1730      11    10  9
 * 0               11  10
 * 0                   11
 *
 * first row: 2, 5, 8, 11
 * second: 1, 4, 7, 10
 * third: 0, 3, 6, 9
 * Read a new sample after passing the last line.
 */
void PolyphaseFilter::Generate( const float *pFIR )
{
	float *pOutput=m_pPolyphase;
	int iInputSize = L*m_iUpFactor;

	for( int iRow = 0; iRow < m_iUpFactor; ++iRow )
	{
		int iInputOffset = (m_iUpFactor-iRow-1) % m_iUpFactor;
		for( int iCol = 0; iCol < L; ++iCol )
		{
			*pOutput = pFIR[iInputOffset];
			++pOutput;
			iInputOffset += m_iUpFactor;
			iInputOffset %= iInputSize;
		}
	}
}

/*
 * We only want one boundary check when running the filter; either on the
 * number of inputs used, or the number of outputs produced.  Otherwise, we'll
 * have to maintain two counters, and check two values per iteration.
 *
 * First, call NumInputsForOutputSamples(out), to find out how many inputs to supply to get
 * the desired number of outputs.  Then, pass the data, the input count
 * and the output count to RunPolyphaseFilter.
 *
 * - When downsampling, we use the number of inputs as the boundary.  For example,
 * if the ratio is 1:3 (downsample x3), and the user gives us 10 samples, then we
 * process until we've consumed all of the input.  (This will result in exactly
 * the number of samples the user asked for with NumInputsForOutputSamples.)
 *
 * - When upsampling, we use the number of outputs as the boundary.  For example,
 * if the ratio is 3:1 (upsample x3), and the user wants 8 samples to be output,
 * we'll have been given 3 samples as input.  Process until we've produced 8
 * samples.
 *
 * In both cases, we have overlap.  In the first, it's possible that we could
 * have consumed an additional input without producing an output.  In the second,
 * it's possible that we could have produced an additional output without
 * consuming an input.
 */
int PolyphaseFilter::RunPolyphaseFilter(
		State &State,
		const float *pIn, int iSamplesIn, int iDownFactor,
		float *pOut, int iSamplesOut,
		int iSampleStride ) const
{
	ASSERT( iSamplesIn >= 0 );

	float *pOutOrig = pOut;
	const float *pInEnd = pIn + iSamplesIn*iSampleStride;
	const float *pOutEnd = pOut + iSamplesOut*iSampleStride;

	int iFilled = State.m_iFilled;
	int iPolyIndex = State.m_iPolyIndex;
	while( pOut != pOutEnd )
	{
		if( iFilled < L )
		{
			if( pIn == pInEnd )
				break;

			State.m_fBuf[State.m_iBufNext] = *pIn;
			State.m_fBuf[State.m_iBufNext + L] = *pIn;
			++State.m_iBufNext;
			State.m_iBufNext &= L-1;

			pIn += iSampleStride;
			++iFilled;
			continue;
		}

		while( pOut != pOutEnd )
		{
			const float *pCurPoly = &m_pPolyphase[iPolyIndex*L];
			const float *pInData = &State.m_fBuf[State.m_iBufNext];

			float fTot = 0;
			for( int j = 0; j < L; ++j )
				fTot += pInData[j]*pCurPoly[j];
			*pOut = fTot;
			pOut += iSampleStride;

			iPolyIndex += iDownFactor;
			if( iPolyIndex >= m_iUpFactor )
				break;
		}
		iFilled -= iPolyIndex/m_iUpFactor;
		iPolyIndex %= m_iUpFactor;
	}

	State.m_iFilled = iFilled;
	State.m_iPolyIndex = iPolyIndex;

	int iRetSamples = pOut - pOutOrig;
	int iRetFrames = iRetSamples / iSampleStride;
	return iRetFrames;
}

/*
 * Return the number of input samples needed to produce the given number of output
 * samples.  This is dependent on the number of bytes in the buffer and the current
 * position of the stream.
 */
int PolyphaseFilter::NumInputsForOutputSamples( const State &State, int iOut, int iDownFactor ) const
{
	int iIn = 0;
	int iFilled = State.m_iFilled;
	int iPolyIndex = State.m_iPolyIndex;

#if 0
	while( iOut > 0 )
	{
		if( iFilled < L )
		{
			int iToFill = L-iFilled;
			iIn += iToFill;
			iFilled += iToFill;
		}

		while( iFilled == L && iOut )
		{
			--iOut;
			iPolyIndex += iDownFactor;

			if( iPolyIndex >= m_iUpFactor )
				break;
		}
		iFilled -= iPolyIndex/m_iUpFactor;
		iPolyIndex %= m_iUpFactor;
	}
#endif

	if( iOut > 0 )
	{
		if( iFilled < L )
		{
			int iToFill = L-iFilled;
			iIn += iToFill;
		}

		// The -1 here is because we don't refill m_fBuf after writing the last output.
		iPolyIndex += iDownFactor*(iOut-1);
		iIn += iPolyIndex/m_iUpFactor;
	}

	return iIn;
}
/** @brief Utilities for working with the PolyphaseFilter cache. */
namespace PolyphaseFilterCache
{
	/* Cache filter data, and reuse it without copying.  All operations after creation
	 * are const, so this doesn't cause thread-safety problems. */
	typedef std::map<std::pair<int, float>, PolyphaseFilter*> FilterMap;
	static RageMutex PolyphaseFiltersLock("PolyphaseFiltersLock");
	static FilterMap g_mapPolyphaseFilters;

	const PolyphaseFilter *MakePolyphaseFilter( int iUpFactor, float fCutoffFrequency )
	{
		PolyphaseFiltersLock.Lock();
		std::pair<int, float> params( std::make_pair(iUpFactor, fCutoffFrequency) );
		FilterMap::const_iterator it = g_mapPolyphaseFilters.find(params);
		if( it != g_mapPolyphaseFilters.end() )
		{
			/* We already have a filter for this upsampling factor and cutoff; use it. */
			PolyphaseFilter *pPolyphase = it->second;
			PolyphaseFiltersLock.Unlock();
			return pPolyphase;
		}
		int iWinSize = L*iUpFactor;
		float *pFIR = new float[iWinSize];
		GenerateSincLowPassFilter( pFIR, iWinSize, fCutoffFrequency );
		ApplyKaiserWindow( pFIR, iWinSize, 8 );
		NormalizeVector( pFIR, iWinSize );
		MultiplyVector( &pFIR[0], &pFIR[iWinSize], (float) iUpFactor );

		PolyphaseFilter *pPolyphase = new PolyphaseFilter( iUpFactor );
		pPolyphase->Generate( pFIR );
		delete [] pFIR;

		g_mapPolyphaseFilters[params] = pPolyphase;
		PolyphaseFiltersLock.Unlock();
		return pPolyphase;
	}

	const PolyphaseFilter *FindNearestPolyphaseFilter( int iUpFactor, float fCutoffFrequency )
	{
		/* Find a cached filter with the same iUpFactor and a nearby cutoff frequency.
		 * Round the cutoff down, if possible; it's better to filter out too much than
		 * too little. */
		PolyphaseFiltersLock.Lock();
		std::pair<int, float> params( std::make_pair(iUpFactor, fCutoffFrequency + 0.0001f) );
		FilterMap::const_iterator it = g_mapPolyphaseFilters.upper_bound( params );
		if( it != g_mapPolyphaseFilters.begin() )
			--it;
		ASSERT( it->first.first == iUpFactor );
		PolyphaseFilter *pPolyphase = it->second;
		PolyphaseFiltersLock.Unlock();
		return pPolyphase;
	}
}

/*
 * Interface to PolyphaseFilter, providing a simple resampling interface.  This handles
 * reuse of PolyphaseFilters.  This does not handle delay, flushing, or multiple channels.
 */
class RageSoundResampler_Polyphase
{
public:
	/* Note that going outside of [iMinDownFactor,iMaxDownFactor] while resampling isn't
	 * fatal.  It'll only cause aliasing, by not having a LPF that's low enough, or cause
	 * too much filtering, by not having a LPF that's high enough. */
	RageSoundResampler_Polyphase( int iUpFactor, int iMinDownFactor, int iMaxDownFactor )
	{
		/* Cache filters between iMinDownFactor and iMaxDownFactor.  Do them in
		 * iFilterIncrement increments; we'll round down to the closest match
		 * when filtering.  This will only cause the low-pass filter to be rounded;
		 * the conversion ratio will always be exact. */
		m_iUpFactor = iUpFactor;
		m_pPolyphase = nullptr;

		int iFilterIncrement = std::max( (iMaxDownFactor - iMinDownFactor)/10, 1 );
		for( int iDownFactor = iMinDownFactor; iDownFactor <= iMaxDownFactor; iDownFactor += iFilterIncrement )
		{
			float fCutoffFrequency = GetCutoffFrequency( iDownFactor );
			PolyphaseFilterCache::MakePolyphaseFilter( m_iUpFactor, fCutoffFrequency );
		}

		SetDownFactor( iUpFactor );

		m_pState = new PolyphaseFilter::State( iUpFactor );
	}

	~RageSoundResampler_Polyphase()
	{
		delete m_pState;
	}

	void SetDownFactor( int iDownFactor )
	{
		m_iDownFactor = iDownFactor;
		m_pPolyphase = GetFilter( m_iDownFactor );
	}

	int Run( const float *pIn, int iSamplesIn, float *pOut, int iSamplesOut, int iSampleStride ) const
	{
		return m_pPolyphase->RunPolyphaseFilter( *m_pState, pIn, iSamplesIn, m_iDownFactor, pOut, iSamplesOut, iSampleStride );
	}

	void Reset()
	{
		delete m_pState;
		m_pState = new PolyphaseFilter::State( m_iUpFactor );
	}

	int NumInputsForOutputSamples( int iOut ) const { return m_pPolyphase->NumInputsForOutputSamples(*m_pState, iOut, m_iDownFactor); }
	int GetLatency() const { return m_pPolyphase->GetLatency(); }
	int GetFilled() const { return m_pState->m_iFilled; }

	RageSoundResampler_Polyphase( const RageSoundResampler_Polyphase &cpy )
	{
		m_pPolyphase = cpy.m_pPolyphase; // don't copy
		m_pState = new PolyphaseFilter::State(*cpy.m_pState);
		m_iUpFactor = cpy.m_iUpFactor;
		m_iDownFactor = cpy.m_iDownFactor;
	}

private:
	float GetCutoffFrequency( int iDownFactor ) const
	{
		/*
		 * If we're upsampling, we want the low-pass filter to cut off at the
		 * nyquist frequency of the original sample.
		 *
		 * If we're downsampling, we want the low-pass filter to cut off at the
		 * nyquist frequency of the new sample.
		 */

		float fCutoffFrequency;
		fCutoffFrequency = 1.0f / (2*m_iUpFactor);
		fCutoffFrequency = std::min( fCutoffFrequency, 1.0f / (2*iDownFactor) );
		return fCutoffFrequency;
	}

	const PolyphaseFilter *GetFilter( int iDownFactor ) const
	{
		float fCutoffFrequency = GetCutoffFrequency( iDownFactor );
		return PolyphaseFilterCache::FindNearestPolyphaseFilter( m_iUpFactor, fCutoffFrequency );
	}

	const PolyphaseFilter *m_pPolyphase;
	PolyphaseFilter::State *m_pState;
	int m_iUpFactor;
	int m_iDownFactor;
};

int RageSoundReader_Resample_Good::GetNextSourceFrame() const
{
	int64_t iPosition = m_pSource->GetNextSourceFrame();
	iPosition -= m_apResamplers[0]->GetFilled();

	iPosition *= m_iSampleRate;
	iPosition /= m_pSource->GetSampleRate();
	return (int) iPosition;
}

bool RageSoundReader_Resample_Good::SetProperty( const RString &sProperty, float fValue )
{
	if( sProperty == "Rate" )
	{
		SetRate( fValue );
		return true;
	}

	return m_pSource->SetProperty( sProperty, fValue );
}

float RageSoundReader_Resample_Good::GetStreamToSourceRatio() const
{
	float fRatio = m_pSource->GetStreamToSourceRatio();
	if( m_fRate != -1 )
		fRatio *= m_fRate;
	return fRatio;
}

RageSoundReader_Resample_Good::RageSoundReader_Resample_Good( RageSoundReader *pSource, int iSampleRate ):
	RageSoundReader_Filter( pSource )
{
	m_iSampleRate = iSampleRate;
	m_fRate = -1;
	ReopenResampler();
}

/* Call this if the input position is changed or reset. */
void RageSoundReader_Resample_Good::Reset()
{
	for( std::size_t iChannel = 0; iChannel < m_pSource->GetNumChannels(); ++iChannel )
		m_apResamplers[iChannel]->Reset();
}


void RageSoundReader_Resample_Good::GetFactors( int &iDownFactor, int &iUpFactor ) const
{
	iDownFactor = m_pSource->GetSampleRate();
	iUpFactor = m_iSampleRate;

	{
		int iGCD = GCD( iUpFactor, iDownFactor );
		iUpFactor /= iGCD;
		iDownFactor /= iGCD;
	}

	bool bRateChangingEnabled = m_fRate != -1;
	if( bRateChangingEnabled )
	{
		iUpFactor *= 100;
		iDownFactor *= 100;
	}
}

/* Call this if the sample factor changes. */
void RageSoundReader_Resample_Good::ReopenResampler()
{
	for( std::size_t iChannel = 0; iChannel < m_apResamplers.size(); ++iChannel )
		delete m_apResamplers[iChannel];
	m_apResamplers.clear();

	int iDownFactor, iUpFactor;
	GetFactors( iDownFactor, iUpFactor );

	for( std::size_t iChannel = 0; iChannel < m_pSource->GetNumChannels(); ++iChannel )
	{
		int iMinDownFactor = iDownFactor;
		int iMaxDownFactor = iDownFactor;
		if( m_fRate != -1 )
			iMaxDownFactor *= 5;

		RageSoundResampler_Polyphase *p = new RageSoundResampler_Polyphase( iUpFactor, iMinDownFactor, iMaxDownFactor );
		m_apResamplers.push_back( p );
	}

	if( m_fRate != -1 )
		iDownFactor = std::lrint( m_fRate * iDownFactor );

	for( std::size_t iChannel = 0; iChannel < m_apResamplers.size(); ++iChannel )
		m_apResamplers[iChannel]->SetDownFactor( iDownFactor );
}

RageSoundReader_Resample_Good::~RageSoundReader_Resample_Good()
{
	for( std::size_t iChannel = 0; iChannel < m_apResamplers.size(); ++iChannel )
		delete m_apResamplers[iChannel];
}

/* iFrame is in the destination rate.  Seek the source in its own sample rate. */
int RageSoundReader_Resample_Good::SetPosition( int iFrame )
{
	Reset();
	iFrame = (int) SCALE( iFrame, 0, (int64_t) m_iSampleRate, 0, (int64_t) m_pSource->GetSampleRate() );
	return m_pSource->SetPosition( iFrame );
}

int RageSoundReader_Resample_Good::Read( float *pBuf, int iFrames )
{
	int iChannels = m_apResamplers.size();

	int iFramesRead = 0;

	/* If the ratio is 1:1, then we're effectively disabled, and we can read
	 * directly into the buffer. */
	int iDownFactor, iUpFactor;
	GetFactors( iDownFactor, iUpFactor );

	if( m_apResamplers[0]->GetFilled() == 0 && iDownFactor == iUpFactor && GetRate() == 1.0f )
		return m_pSource->Read( pBuf, iFrames );

	{
		int iFramesNeeded = m_apResamplers[0]->NumInputsForOutputSamples(iFrames);
		float *pTmpBuf = (float *) alloca( iFramesNeeded * sizeof(float) * iChannels );
		int iFramesIn = m_pSource->Read( pTmpBuf, iFramesNeeded );
		if( iFramesIn < 0 )
			return iFramesIn;

		for( int iChannel = 0; iChannel < iChannels; ++iChannel )
		{
			int iGotFrames = m_apResamplers[iChannel]->Run( pTmpBuf + iChannel, iFramesIn, pBuf + iChannel, iFrames, iChannels );
			ASSERT( iGotFrames <= iFrames );

			if( iChannel == 0 )
				iFramesRead += iGotFrames;
		}
	}

	return iFramesRead;
}

/*
 * A resampler is commonly used for two things: to change the sample rate of audio,
 * in order to give an audio driver what it wants (SetSampleRate), and to change the
 * sound of audio, changing its speed and pitch (SetRate).  These are the same
 * operation, and we do both in the same pass; the only difference is that SetSampleRate
 * causes GetSampleRate() to change, while SetRate() causes GetStreamToSourceRatio() to change.
 *
 * Changing these values will take effect immediately, with a buffering latency of L/4
 * frames.
 */
void RageSoundReader_Resample_Good::SetRate( float fRatio )
{
	ASSERT( fRatio > 0 );
	bool bRateChangingWasEnabled = m_fRate != -1;
	m_fRate = fRatio;

	if( !bRateChangingWasEnabled )
		ReopenResampler();

	int iDownFactor, iUpFactor;
	GetFactors( iDownFactor, iUpFactor );
	if( m_fRate != -1 )
		iDownFactor = std::lrint( m_fRate * iDownFactor );

	/* Set m_fRate to the actual rate, after quantization by iUpFactor. */
	m_fRate = float(iDownFactor) / iUpFactor;

	for( std::size_t iChannel = 0; iChannel < m_apResamplers.size(); ++iChannel )
		m_apResamplers[iChannel]->SetDownFactor( iDownFactor );
}

float RageSoundReader_Resample_Good::GetRate() const
{
	if( m_fRate == -1 )
		return 1.0f;
	else
		return m_fRate;
}

RageSoundReader_Resample_Good::RageSoundReader_Resample_Good( const RageSoundReader_Resample_Good &cpy ):
	RageSoundReader_Filter(cpy)
{
	for( std::size_t i = 0; i < cpy.m_apResamplers.size(); ++i )
		this->m_apResamplers.push_back( new RageSoundResampler_Polyphase(*cpy.m_apResamplers[i]) );
	this->m_iSampleRate = cpy.m_iSampleRate;
	this->m_fRate = cpy.m_fRate;
}

RageSoundReader_Resample_Good *RageSoundReader_Resample_Good::Copy() const
{
	return new RageSoundReader_Resample_Good( *this );
}

/*
 * (c) 2006 Glenn Maynard
 * All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, and/or sell copies of the Software, and to permit persons to
 * whom the Software is furnished to do so, provided that the above
 * copyright notice(s) and this permission notice appear in all copies of
 * the Software and that both the above copyright notice(s) and this
 * permission notice appear in supporting documentation.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF
 * THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS
 * INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT
 * OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */