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1180 lines
29 KiB
C++
Vendored
1180 lines
29 KiB
C++
Vendored
//$ nobt
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//$ nocpp
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/**
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* @file CDSPFracInterpolator.h
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*
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* @brief Fractional delay interpolator and filter bank classes.
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*
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* This file includes fractional delay interpolator class.
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*
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* r8brain-free-src Copyright (c) 2013-2022 Aleksey Vaneev
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* See the "LICENSE" file for license.
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*/
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#ifndef R8B_CDSPFRACINTERPOLATOR_INCLUDED
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#define R8B_CDSPFRACINTERPOLATOR_INCLUDED
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#include "CDSPSincFilterGen.h"
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#include "CDSPProcessor.h"
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namespace r8b {
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#if R8B_FLTTEST
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extern int InterpFilterFracs; ///< Force this number of fractional filter
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///< positions. -1 - use default.
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///<
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#endif // R8B_FLTTEST
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/**
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* @brief Sinc function-based fractional delay filter bank class.
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*
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* Class implements storage and initialization of a bank of sinc-based
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* fractional delay filters, expressed as 0th, 1st, 2nd or 3rd order
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* polynomial interpolation coefficients. The filters are windowed by the
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* "Kaiser" power-raised window function.
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*/
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class CDSPFracDelayFilterBank : public R8B_BASECLASS
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{
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R8BNOCTOR( CDSPFracDelayFilterBank );
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friend class CDSPFracDelayFilterBankCache;
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public:
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/**
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* Constructor.
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*
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* @param aFilterFracs The number of fractional delay positions to sample,
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* -1 - use default.
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* @param aElementSize The size of each filter's tap, in "double" values.
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* This parameter corresponds to the complexity of interpolation. 4 should
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* be set for 3rd order, 3 for 2nd order, 2 for linear interpolation, 1
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* for whole-numbered stepping.
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* @param aInterpPoints The number of points the interpolation is based
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* on. This value should not be confused with the ElementSize. Set to 2
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* for linear or no interpolation.
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* @param aReqAtten Required filter attentuation.
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* @param aIsThird "True" if one-third filter is required.
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*/
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CDSPFracDelayFilterBank( const int aFilterFracs, const int aElementSize,
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const int aInterpPoints, const double aReqAtten, const bool aIsThird )
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: InitFilterFracs( aFilterFracs )
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, ElementSize( aElementSize )
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, InterpPoints( aInterpPoints )
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, ReqAtten( aReqAtten )
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, IsThird( aIsThird )
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, Next( NULL )
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, RefCount( 1 )
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{
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R8BASSERT( ElementSize >= 1 && ElementSize <= 4 );
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// Kaiser window function Params, for half and third-band.
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const double* const Params = getWinParams( ReqAtten, IsThird,
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FilterLen );
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FilterSize = FilterLen * ElementSize;
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if( InitFilterFracs == -1 )
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{
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FilterFracs = (int) ceil( pow( 6.4, ReqAtten / 50.0 ));
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#if R8B_FLTTEST
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if( InterpFilterFracs != -1 )
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{
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FilterFracs = InterpFilterFracs;
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}
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#endif // R8B_FLTTEST
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}
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else
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{
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FilterFracs = InitFilterFracs;
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}
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Table.alloc( FilterSize * ( FilterFracs + InterpPoints ));
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CDSPSincFilterGen sinc;
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sinc.Len2 = FilterLen / 2;
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double* p = Table;
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const int pc2 = InterpPoints / 2;
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int i;
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for( i = -pc2 + 1; i <= FilterFracs + pc2; i++ )
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{
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sinc.FracDelay = (double) ( FilterFracs - i ) / FilterFracs;
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sinc.initFrac( CDSPSincFilterGen :: wftKaiser, Params, true );
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sinc.generateFrac( p, &CDSPSincFilterGen :: calcWindowKaiser,
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ElementSize );
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normalizeFIRFilter( p, FilterLen, 1.0, ElementSize );
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p += FilterSize;
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}
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const int TablePos2 = FilterSize;
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const int TablePos3 = FilterSize * 2;
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const int TablePos4 = FilterSize * 3;
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const int TablePos5 = FilterSize * 4;
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const int TablePos6 = FilterSize * 5;
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const int TablePos7 = FilterSize * 6;
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const int TablePos8 = FilterSize * 7;
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double* const TableEnd = Table + ( FilterFracs + 1 ) * FilterSize;
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p = Table;
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if( InterpPoints == 8 )
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{
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if( ElementSize == 3 )
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{
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// Calculate 2nd order spline (polynomial) interpolation
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// coefficients using 8 points.
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while( p < TableEnd )
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{
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calcSpline2p8Coeffs( p, p[ 0 ], p[ TablePos2 ],
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p[ TablePos3 ], p[ TablePos4 ], p[ TablePos5 ],
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p[ TablePos6 ], p[ TablePos7 ], p[ TablePos8 ]);
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p += ElementSize;
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}
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#if defined( R8B_SIMD_ISH )
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shuffle2_3( Table, TableEnd );
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#endif // SIMD
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}
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else
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if( ElementSize == 4 )
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{
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// Calculate 3rd order spline (polynomial) interpolation
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// coefficients using 8 points.
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while( p < TableEnd )
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{
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calcSpline3p8Coeffs( p, p[ 0 ], p[ TablePos2 ],
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p[ TablePos3 ], p[ TablePos4 ], p[ TablePos5 ],
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p[ TablePos6 ], p[ TablePos7 ], p[ TablePos8 ]);
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p += ElementSize;
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}
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#if defined( R8B_SIMD_ISH )
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shuffle2_4( Table, TableEnd );
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#endif // SIMD
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}
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}
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else
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{
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if( ElementSize == 2 )
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{
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// Calculate linear interpolation coefficients.
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while( p < TableEnd )
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{
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p[ 1 ] = p[ TablePos2 ] - p[ 0 ];
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p += ElementSize;
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}
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#if defined( R8B_SIMD_ISH )
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shuffle2_2( Table, TableEnd );
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#endif // SIMD
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}
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}
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R8BCONSOLE( "CDSPFracDelayFilterBank: fracs=%i order=%i taps=%i "
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"att=%.1f third=%i\n", FilterFracs, ElementSize - 1, FilterLen,
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ReqAtten, (int) IsThird );
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}
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~CDSPFracDelayFilterBank()
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{
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delete Next;
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}
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/**
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* Function "rounds" the specified attenuation to the nearest effective
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* value.
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*
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* @param[in,out] att Required filter attentuation. Will be rounded to the
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* nearest value.
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* @param aIsThird "True" if one-third filter is required.
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*/
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static void roundReqAtten( double& att, const bool aIsThird )
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{
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int tmp;
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getWinParams( att, aIsThird, tmp );
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}
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/**
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* Function returns the length of the filter. Always an even number, not
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* less than 6.
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*/
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int getFilterLen() const
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{
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return( FilterLen );
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}
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/**
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* Function returns the number of fractional positions sampled by the
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* bank.
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*/
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int getFilterFracs() const
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{
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return( FilterFracs );
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}
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/**
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* @param i Filter index, in the range 0 to FilterFracs, inclusive.
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* @return Reference to the filter.
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*/
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const double& operator []( const int i ) const
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{
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R8BASSERT( i >= 0 && i <= FilterFracs );
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return( Table[ i * FilterSize ]);
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}
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/**
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* This function should be called when the filter bank obtained via the
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* filter bank cache is no longer needed.
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*/
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void unref();
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private:
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int FilterLen; ///< Filter length. Always an even number, not less than 6.
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///<
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int FilterFracs; ///< Fractional position count.
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///<
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int InitFilterFracs; ///< Fractional position count as supplied to the
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///< constructor, may equal -1.
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///<
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int ElementSize; ///< Filter element size.
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///<
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int InterpPoints; ///< Interpolation points to use.
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///<
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double ReqAtten; ///< Filter's attentuation.
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///<
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bool IsThird; ///< "True" if one-third filter is in use.
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///<
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int FilterSize; ///< This constant specifies the "size" of a single filter
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///< in "double" elements.
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///<
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CFixedBuffer< double > Table; ///< The table of fractional delay filters
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///< for all discrete fractional x = 0..1 sample positions, and
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///< interpolation coefficients.
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///<
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CDSPFracDelayFilterBank* Next; ///< Next filter bank in cache's list.
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///<
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int RefCount; ///< The number of references made to *this filter bank.
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///< Not considered for "static" filter bank objects.
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///<
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/**
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* Function returns windowing function parameters for the specified
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* attenuation and filter type.
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*
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* @param[in,out] att Required filter attentuation. Will be rounded to the
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* nearest value.
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* @param aIsThird "True" if one-third filter is required.
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* @param[out] fltlen Resulting filter length.
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*/
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static const double* getWinParams( double& att, const bool aIsThird,
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int& fltlen )
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{
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static const int Coeffs2Base = 8;
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static const int Coeffs2Count = 12;
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static const double Coeffs2[ Coeffs2Count ][ 3 ] = {
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{ 4.1308468534586913, 1.1752580009977263, 55.5446 }, // 0.0256
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{ 4.4241520324148826, 1.8004881791443044, 81.4191 }, // 0.0886
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{ 5.2615232289173663, 1.8133318236025469, 96.3392 }, // 0.0481
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{ 5.9433751227216174, 1.8730186391986436, 111.1315 }, // 0.0264
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{ 6.8308658290513815, 1.8549555110340281, 125.4653 }, // 0.0146
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{ 7.6648458290312904, 1.8565766090828464, 139.7379 }, // 0.0081
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{ 8.2038728664307605, 1.9269521820570166, 154.0532 }, // 0.0045
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{ 8.7865150946655142, 1.9775307667441668, 168.2101 }, // 0.0025
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{ 9.5945017884101773, 1.9718456992078597, 182.1076 }, // 0.0014
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{ 10.5163141145985240, 1.9504067820201083, 195.5668 }, // 0.0008
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{ 10.2382465206362470, 2.1608923446870087, 209.0610 }, // 0.0004
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{ 10.9976060250714000, 2.1536533525688935, 222.5010 }, // 0.0003
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};
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static const int Coeffs3Base = 6;
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static const int Coeffs3Count = 10;
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static const double Coeffs3[ Coeffs3Count ][ 3 ] = {
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{ 3.9888564562781847, 1.5869927184268915, 66.5701 }, // 0.0467
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{ 4.6986694038145007, 1.8086068597928262, 86.4715 }, // 0.0136
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{ 5.5995071329337822, 1.8930163360942349, 106.1195 }, // 0.0040
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{ 6.3627287800257228, 1.9945748322093975, 125.2307 }, // 0.0012
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{ 7.4299550711428308, 1.9893400572347544, 144.3469 }, // 0.0004
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{ 8.0667715944075642, 2.0928201458699909, 163.4099 }, // 0.0001
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{ 8.7469970226288822, 2.1640279784268355, 181.0694 }, // 0.0000
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{ 10.0823430069835230, 2.0896678025321922, 199.2880 }, // 0.0000
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{ 10.9222206090489510, 2.1221681162186004, 216.6865 }, // 0.0000
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{ 21.2017743894772010, 1.1856768080118900, 233.9188 }, // 0.0000
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};
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const double* Params;
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int i = 0;
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if( aIsThird )
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{
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while( i != Coeffs3Count - 1 && Coeffs3[ i ][ 2 ] < att )
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{
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i++;
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}
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Params = &Coeffs3[ i ][ 0 ];
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att = Coeffs3[ i ][ 2 ];
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fltlen = Coeffs3Base + i * 2;
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}
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else
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{
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while( i != Coeffs2Count - 1 && Coeffs2[ i ][ 2 ] < att )
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{
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i++;
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}
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Params = &Coeffs2[ i ][ 0 ];
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att = Coeffs2[ i ][ 2 ];
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fltlen = Coeffs2Base + i * 2;
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}
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return( Params );
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}
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/**
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* Function shuffles 2 order-2 filter points for SIMD operation.
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*
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* @param p Filter table start pointer.
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* @param pe Filter table end pointer.
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*/
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static void shuffle2_2( double* p, double* const pe )
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{
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while( p != pe )
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{
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const double t = p[ 2 ];
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p[ 2 ] = p[ 1 ];
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p[ 1 ] = t;
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p += 4;
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}
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}
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/**
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* Function shuffles 2 order-3 filter points for SIMD operation.
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*
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* @param p Filter table start pointer.
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* @param pe Filter table end pointer.
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*/
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static void shuffle2_3( double* p, double* const pe )
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{
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while( p != pe )
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{
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const double t1 = p[ 1 ];
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const double t2 = p[ 2 ];
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const double t3 = p[ 3 ];
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const double t4 = p[ 4 ];
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p[ 1 ] = t3;
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p[ 2 ] = t1;
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p[ 3 ] = t4;
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p[ 4 ] = t2;
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p += 6;
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}
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}
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/**
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* Function shuffles 2 order-4 filter points for SIMD operation.
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*
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* @param p Filter table start pointer.
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* @param pe Filter table end pointer.
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*/
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static void shuffle2_4( double* p, double* const pe )
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{
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while( p != pe )
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{
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const double t1 = p[ 1 ];
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const double t2 = p[ 2 ];
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const double t3 = p[ 3 ];
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const double t4 = p[ 4 ];
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const double t5 = p[ 5 ];
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const double t6 = p[ 6 ];
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p[ 1 ] = t4;
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p[ 2 ] = t1;
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p[ 3 ] = t5;
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p[ 4 ] = t2;
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p[ 5 ] = t6;
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p[ 6 ] = t3;
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p += 8;
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}
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}
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};
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/**
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* @brief Fractional delay filter cache class.
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*
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* Class implements cache storage of fractional delay filter banks.
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*/
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class CDSPFracDelayFilterBankCache : public R8B_BASECLASS
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{
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R8BNOCTOR( CDSPFracDelayFilterBankCache );
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friend class CDSPFracDelayFilterBank;
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public:
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/**
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* @return The number of filters present in the cache now. This value can
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* be monitored for debugging "forgotten" filters.
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*/
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static int getObjCount()
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{
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R8BSYNC( StateSync );
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return( ObjCount );
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}
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/**
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* Function calculates or returns reference to a previously calculated
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* (cached) fractional delay filter bank.
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*
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* @param aFilterFracs The number of fractional delay positions to sample,
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* -1 - use default.
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* @param aElementSize The size of each filter's tap, in "double" values.
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* @param aInterpPoints The number of points the interpolation is based
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* on.
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* @param ReqAtten Required filter attentuation.
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* @param IsThird "True" if one-third filter is required.
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* @param IsStatic "True" if a permanent static filter should be returned
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* that is never removed from the cache until application terminates.
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*/
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static CDSPFracDelayFilterBank& getFilterBank( const int aFilterFracs,
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const int aElementSize, const int aInterpPoints,
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double ReqAtten, const bool IsThird, const bool IsStatic )
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{
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CDSPFracDelayFilterBank :: roundReqAtten( ReqAtten, IsThird );
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R8BSYNC( StateSync );
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if( IsStatic )
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{
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CDSPFracDelayFilterBank* CurObj = StaticObjects;
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while( CurObj != NULL )
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{
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if( CurObj -> InitFilterFracs == aFilterFracs &&
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CurObj -> ElementSize == aElementSize &&
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CurObj -> InterpPoints == aInterpPoints &&
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CurObj -> ReqAtten == ReqAtten &&
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CurObj -> IsThird == IsThird )
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{
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return( *CurObj );
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}
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CurObj = CurObj -> Next;
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}
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// Create a new filter bank and build it.
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CurObj = new CDSPFracDelayFilterBank( aFilterFracs, aElementSize,
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aInterpPoints, ReqAtten, IsThird );
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// Insert the bank at the start of the list.
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CurObj -> Next = StaticObjects.unkeep();
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StaticObjects = CurObj;
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return( *CurObj );
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}
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CDSPFracDelayFilterBank* PrevObj = NULL;
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CDSPFracDelayFilterBank* CurObj = Objects;
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while( CurObj != NULL )
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{
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if( CurObj -> InitFilterFracs == aFilterFracs &&
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CurObj -> ElementSize == aElementSize &&
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CurObj -> InterpPoints == aInterpPoints &&
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CurObj -> ReqAtten == ReqAtten &&
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CurObj -> IsThird == IsThird )
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{
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break;
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}
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if( CurObj -> Next == NULL && ObjCount >= R8B_FRACBANK_CACHE_MAX )
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{
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if( CurObj -> RefCount == 0 )
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{
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// Delete the last bank which is not used.
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PrevObj -> Next = NULL;
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delete CurObj;
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ObjCount--;
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}
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else
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{
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// Move the last bank to the top of the list since it
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// seems to be in use for a long time.
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|
|
PrevObj -> Next = NULL;
|
|
CurObj -> Next = Objects.unkeep();
|
|
Objects = CurObj;
|
|
}
|
|
|
|
CurObj = NULL;
|
|
break;
|
|
}
|
|
|
|
PrevObj = CurObj;
|
|
CurObj = CurObj -> Next;
|
|
}
|
|
|
|
if( CurObj != NULL )
|
|
{
|
|
CurObj -> RefCount++;
|
|
|
|
if( PrevObj == NULL )
|
|
{
|
|
return( *CurObj );
|
|
}
|
|
|
|
// Remove the bank from the list temporarily.
|
|
|
|
PrevObj -> Next = CurObj -> Next;
|
|
}
|
|
else
|
|
{
|
|
// Create a new filter bank (with RefCount == 1) and build it.
|
|
|
|
CurObj = new CDSPFracDelayFilterBank( aFilterFracs, aElementSize,
|
|
aInterpPoints, ReqAtten, IsThird );
|
|
|
|
ObjCount++;
|
|
}
|
|
|
|
// Insert the bank at the start of the list.
|
|
|
|
CurObj -> Next = Objects.unkeep();
|
|
Objects = CurObj;
|
|
|
|
return( *CurObj );
|
|
}
|
|
|
|
private:
|
|
static CSyncObject StateSync; ///< Cache state synchronizer.
|
|
///<
|
|
static CPtrKeeper< CDSPFracDelayFilterBank* > Objects; ///< The chain of
|
|
///< cached objects.
|
|
///<
|
|
static CPtrKeeper< CDSPFracDelayFilterBank* > StaticObjects; ///< The
|
|
///< chain of static objects.
|
|
///<
|
|
static int ObjCount; ///< The number of objects currently preset in the
|
|
///< Objects cache.
|
|
///<
|
|
};
|
|
|
|
// ---------------------------------------------------------------------------
|
|
// CDSPFracDelayFilterBank PUBLIC
|
|
// ---------------------------------------------------------------------------
|
|
|
|
inline void CDSPFracDelayFilterBank :: unref()
|
|
{
|
|
R8BSYNC( CDSPFracDelayFilterBankCache :: StateSync );
|
|
|
|
RefCount--;
|
|
}
|
|
|
|
/**
|
|
* @param l Number 1.
|
|
* @param s Number 2.
|
|
* @param[out] GCD Resulting GCD.
|
|
* @return "True" if the greatest common denominator of 2 numbers was
|
|
* found.
|
|
*/
|
|
|
|
inline bool findGCD( double l, double s, double& GCD )
|
|
{
|
|
int it = 0;
|
|
|
|
while( it < 50 )
|
|
{
|
|
if( s <= 0.0 )
|
|
{
|
|
GCD = l;
|
|
return( true );
|
|
}
|
|
|
|
const double r = l - s;
|
|
l = s;
|
|
s = ( r < 0.0 ? -r : r );
|
|
it++;
|
|
}
|
|
|
|
return( false );
|
|
}
|
|
|
|
/**
|
|
* Function evaluates source and destination sample rate ratio and returns
|
|
* the required input and output stepping. Function returns "false" if
|
|
* whole stepping cannot be used to perform interpolation using these sample
|
|
* rates.
|
|
*
|
|
* @param SSampleRate Source sample rate.
|
|
* @param DSampleRate Destination sample rate.
|
|
* @param[out] ResInStep Resulting input step.
|
|
* @param[out] ResOutStep Resulting output step.
|
|
* @return "True" if stepping was acquired.
|
|
*/
|
|
|
|
inline bool getWholeStepping( const double SSampleRate,
|
|
const double DSampleRate, int& ResInStep, int& ResOutStep )
|
|
{
|
|
double GCD;
|
|
|
|
if( !findGCD( SSampleRate, DSampleRate, GCD ) || GCD < 1.0 )
|
|
{
|
|
return( false );
|
|
}
|
|
|
|
const double InStep0 = SSampleRate / GCD;
|
|
ResInStep = (int) InStep0;
|
|
const double OutStep0 = DSampleRate / GCD;
|
|
ResOutStep = (int) OutStep0;
|
|
|
|
if( InStep0 != ResInStep || OutStep0 != ResOutStep )
|
|
{
|
|
return( false );
|
|
}
|
|
|
|
if( ResOutStep > 1500 )
|
|
{
|
|
// Do not allow large output stepping due to low cache
|
|
// performance of large filter banks.
|
|
|
|
return( false );
|
|
}
|
|
|
|
return( true );
|
|
}
|
|
|
|
/**
|
|
* @brief Fractional delay filter bank-based interpolator class.
|
|
*
|
|
* Class implements the fractional delay interpolator. This implementation at
|
|
* first puts the input signal into a ring buffer and then performs
|
|
* interpolation. The interpolation is performed using sinc-based fractional
|
|
* delay filters. These filters are contained in a bank, and for higher
|
|
* precision they are interpolated between adjacent filters.
|
|
*
|
|
* To increase sample timing precision, this class uses "resettable counter"
|
|
* approach. This gives zero overall sample timing error. With the
|
|
* R8B_FASTTIMING configuration option enabled, the sample timing experiences
|
|
* a very minor drift.
|
|
*/
|
|
|
|
class CDSPFracInterpolator : public CDSPProcessor
|
|
{
|
|
public:
|
|
/**
|
|
* Constructor initalizes the interpolator. It is important to call the
|
|
* getMaxOutLen() function afterwards to obtain the optimal output buffer
|
|
* length.
|
|
*
|
|
* @param aSrcSampleRate Source sample rate.
|
|
* @param aDstSampleRate Destination sample rate.
|
|
* @param ReqAtten Required filter attentuation.
|
|
* @param IsThird "True" if one-third filter is required.
|
|
* @param PrevLatency Latency, in samples (any value >=0), which was left
|
|
* in the output signal by a previous process. This latency will be
|
|
* consumed completely.
|
|
*/
|
|
|
|
CDSPFracInterpolator( const double aSrcSampleRate,
|
|
const double aDstSampleRate, const double ReqAtten,
|
|
const bool IsThird, const double PrevLatency )
|
|
: SrcSampleRate( aSrcSampleRate )
|
|
, DstSampleRate( aDstSampleRate )
|
|
#if R8B_FASTTIMING
|
|
, FracStep( aSrcSampleRate / aDstSampleRate )
|
|
#endif // R8B_FASTTIMING
|
|
{
|
|
R8BASSERT( SrcSampleRate > 0.0 );
|
|
R8BASSERT( DstSampleRate > 0.0 );
|
|
R8BASSERT( PrevLatency >= 0.0 );
|
|
R8BASSERT( BufLenBits >= 5 );
|
|
|
|
InitFracPos = PrevLatency;
|
|
Latency = (int) InitFracPos;
|
|
InitFracPos -= Latency;
|
|
|
|
R8BASSERT( Latency >= 0 );
|
|
|
|
#if R8B_FLTTEST
|
|
|
|
IsWhole = false;
|
|
LatencyFrac = 0.0;
|
|
FilterBank = new CDSPFracDelayFilterBank( -1, 3, 8, ReqAtten,
|
|
IsThird );
|
|
|
|
#else // R8B_FLTTEST
|
|
|
|
IsWhole = getWholeStepping( SrcSampleRate, DstSampleRate, InStep,
|
|
OutStep );
|
|
|
|
if( IsWhole )
|
|
{
|
|
InitFracPosW = (int) ( InitFracPos * OutStep );
|
|
LatencyFrac = InitFracPos - (double) InitFracPosW / OutStep;
|
|
FilterBank = &CDSPFracDelayFilterBankCache :: getFilterBank(
|
|
OutStep, 1, 2, ReqAtten, IsThird, false );
|
|
}
|
|
else
|
|
{
|
|
LatencyFrac = 0.0;
|
|
FilterBank = &CDSPFracDelayFilterBankCache :: getFilterBank(
|
|
-1, 3, 8, ReqAtten, IsThird, true );
|
|
}
|
|
|
|
#endif // R8B_FLTTEST
|
|
|
|
FilterLen = FilterBank -> getFilterLen();
|
|
fl2 = FilterLen >> 1;
|
|
fll = fl2 - 1;
|
|
flo = fll + fl2;
|
|
flb = BufLen - fll;
|
|
|
|
R8BASSERT(( 1 << BufLenBits ) >= FilterLen * 3 );
|
|
|
|
static const CConvolveFn FltConvFn0[ 13 ] = {
|
|
&CDSPFracInterpolator :: convolve0< 6 >,
|
|
&CDSPFracInterpolator :: convolve0< 8 >,
|
|
&CDSPFracInterpolator :: convolve0< 10 >,
|
|
&CDSPFracInterpolator :: convolve0< 12 >,
|
|
&CDSPFracInterpolator :: convolve0< 14 >,
|
|
&CDSPFracInterpolator :: convolve0< 16 >,
|
|
&CDSPFracInterpolator :: convolve0< 18 >,
|
|
&CDSPFracInterpolator :: convolve0< 20 >,
|
|
&CDSPFracInterpolator :: convolve0< 22 >,
|
|
&CDSPFracInterpolator :: convolve0< 24 >,
|
|
&CDSPFracInterpolator :: convolve0< 26 >,
|
|
&CDSPFracInterpolator :: convolve0< 28 >,
|
|
&CDSPFracInterpolator :: convolve0< 30 >
|
|
};
|
|
|
|
convfn = ( IsWhole ? FltConvFn0[ fl2 - 3 ] :
|
|
&CDSPFracInterpolator :: convolve2 );
|
|
|
|
R8BCONSOLE( "CDSPFracInterpolator: src=%.2f dst=%.2f taps=%i "
|
|
"fracs=%i whole=%i third=%i step=%.6f\n", SrcSampleRate,
|
|
DstSampleRate, FilterLen, ( IsWhole ? OutStep :
|
|
FilterBank -> getFilterFracs() ), (int) IsWhole, (int) IsThird,
|
|
aSrcSampleRate / aDstSampleRate );
|
|
|
|
clear();
|
|
}
|
|
|
|
virtual ~CDSPFracInterpolator()
|
|
{
|
|
#if R8B_FLTTEST
|
|
|
|
delete FilterBank;
|
|
|
|
#else // R8B_FLTTEST
|
|
|
|
FilterBank -> unref();
|
|
|
|
#endif // R8B_FLTTEST
|
|
}
|
|
|
|
virtual int getLatency() const
|
|
{
|
|
return( 0 );
|
|
}
|
|
|
|
virtual double getLatencyFrac() const
|
|
{
|
|
return( LatencyFrac );
|
|
}
|
|
|
|
virtual int getMaxOutLen( const int MaxInLen ) const
|
|
{
|
|
R8BASSERT( MaxInLen >= 0 );
|
|
|
|
return( (int) ceil( MaxInLen * DstSampleRate / SrcSampleRate ) + 1 );
|
|
}
|
|
|
|
virtual void clear()
|
|
{
|
|
LatencyLeft = Latency;
|
|
BufLeft = 0;
|
|
WritePos = 0;
|
|
ReadPos = flb; // Set "read" position to account for filter's
|
|
// latency at zero fractional delay.
|
|
|
|
memset( &Buf[ ReadPos ], 0, ( BufLen - flb ) * sizeof( Buf[ 0 ]));
|
|
|
|
if( IsWhole )
|
|
{
|
|
InPosFracW = InitFracPosW;
|
|
}
|
|
else
|
|
{
|
|
InPosFrac = InitFracPos;
|
|
|
|
#if !R8B_FASTTIMING
|
|
InCounter = 0;
|
|
InPosInt = 0;
|
|
InPosShift = InitFracPos * DstSampleRate / SrcSampleRate;
|
|
#endif // !R8B_FASTTIMING
|
|
}
|
|
}
|
|
|
|
virtual int process( double* ip, int l, double*& op0 )
|
|
{
|
|
R8BASSERT( l >= 0 );
|
|
R8BASSERT( ip != op0 || l == 0 || SrcSampleRate > DstSampleRate );
|
|
|
|
if( LatencyLeft != 0 )
|
|
{
|
|
if( LatencyLeft >= l )
|
|
{
|
|
LatencyLeft -= l;
|
|
return( 0 );
|
|
}
|
|
|
|
l -= LatencyLeft;
|
|
ip += LatencyLeft;
|
|
LatencyLeft = 0;
|
|
}
|
|
|
|
double* op = op0;
|
|
|
|
while( l > 0 )
|
|
{
|
|
// Add new input samples to both halves of the ring buffer.
|
|
|
|
const int b = min( min( l, BufLen - WritePos ), flb - BufLeft );
|
|
|
|
double* const wp1 = Buf + WritePos;
|
|
memcpy( wp1, ip, b * sizeof( wp1[ 0 ]));
|
|
|
|
if( WritePos < flo )
|
|
{
|
|
const int c = min( b, flo - WritePos );
|
|
memcpy( wp1 + BufLen, wp1, c * sizeof( wp1[ 0 ]));
|
|
}
|
|
|
|
ip += b;
|
|
WritePos = ( WritePos + b ) & BufLenMask;
|
|
l -= b;
|
|
BufLeft += b;
|
|
|
|
// Produce as many output samples as possible.
|
|
|
|
op = ( *this.*convfn )( op );
|
|
}
|
|
|
|
#if !R8B_FASTTIMING
|
|
|
|
if( !IsWhole && InCounter > 1000 )
|
|
{
|
|
// Reset the interpolation position counter to achieve a
|
|
// higher sample timing precision.
|
|
|
|
InCounter = 0;
|
|
InPosInt = 0;
|
|
InPosShift = InPosFrac * DstSampleRate / SrcSampleRate;
|
|
}
|
|
|
|
#endif // !R8B_FASTTIMING
|
|
|
|
return( (int) ( op - op0 ));
|
|
}
|
|
|
|
private:
|
|
static const int BufLenBits = 8; ///< The length of the ring buffer,
|
|
///< expressed as Nth power of 2. This value can be reduced if it is
|
|
///< known that only short input buffers will be passed to the
|
|
///< interpolator. The minimum value of this parameter is 5, and
|
|
///< 1 << BufLenBits should be at least 3 times larger than the
|
|
///< FilterLen. However, this condition can be easily met if the input
|
|
///< signal is suitably downsampled first before the interpolation is
|
|
///< performed.
|
|
///<
|
|
static const int BufLen = 1 << BufLenBits; ///< The length of the ring
|
|
///< buffer. The actual length is twice as long to allow "beyond max
|
|
///< position" positioning.
|
|
///<
|
|
static const int BufLenMask = BufLen - 1; ///< Mask used for quick buffer
|
|
///< position wrapping.
|
|
///<
|
|
int FilterLen; ///< Filter length, in taps. Even value.
|
|
///<
|
|
int fl2; ///< Right-side (half) filter length.
|
|
///<
|
|
int fll; ///< Input latency.
|
|
///<
|
|
int flo; ///< Overrun length.
|
|
///<
|
|
int flb; ///< Initial read position and maximal buffer write length.
|
|
///<
|
|
double Buf[ BufLen + 29 ]; ///< The ring buffer, including overrun
|
|
///< protection for maximal filter length.
|
|
///<
|
|
double SrcSampleRate; ///< Source sample rate.
|
|
///<
|
|
double DstSampleRate; ///< Destination sample rate.
|
|
///<
|
|
bool IsWhole; ///< "True" if whole-number stepping is in use.
|
|
///<
|
|
int InStep; ///< Input whole-number stepping.
|
|
///<
|
|
int OutStep; ///< Output whole-number stepping (corresponds to filter bank
|
|
///< size).
|
|
///<
|
|
double InitFracPos; ///< Initial fractional position, in samples, in the
|
|
///< range [0; 1).
|
|
///<
|
|
int InitFracPosW; ///< Initial fractional position for whole-number
|
|
///< stepping.
|
|
///<
|
|
int Latency; ///< Initial latency that should be removed from the input.
|
|
///<
|
|
double LatencyFrac; ///< Left-over fractional latency.
|
|
///<
|
|
int BufLeft; ///< The number of samples left in the buffer to process.
|
|
///<
|
|
int WritePos; ///< The current buffer write position. Incremented together
|
|
///< with the BufLeft variable.
|
|
///<
|
|
int ReadPos; ///< The current buffer read position.
|
|
///<
|
|
int LatencyLeft; ///< Input latency left to remove.
|
|
///<
|
|
double InPosFrac; ///< Interpolation position (fractional part).
|
|
///<
|
|
int InPosFracW; ///< Interpolation position (fractional part) for
|
|
///< whole-number stepping. Corresponds to the index into the filter
|
|
///< bank.
|
|
///<
|
|
CDSPFracDelayFilterBank* FilterBank; ///< Filter bank in use, may be
|
|
///< whole-number stepping filter bank or static bank.
|
|
///<
|
|
#if R8B_FASTTIMING
|
|
double FracStep; ///< Fractional sample timing step.
|
|
#else // R8B_FASTTIMING
|
|
int InCounter; ///< Interpolation step counter.
|
|
///<
|
|
int InPosInt; ///< Interpolation position (integer part).
|
|
///<
|
|
double InPosShift; ///< Interpolation position fractional shift.
|
|
///<
|
|
#endif // R8B_FASTTIMING
|
|
|
|
typedef double*( CDSPFracInterpolator :: *CConvolveFn )( double* op ); ///<
|
|
///< Convolution function type.
|
|
///<
|
|
CConvolveFn convfn; ///< Convolution function in use.
|
|
///<
|
|
|
|
/**
|
|
* Convolution function for 0th order resampling.
|
|
*
|
|
* @param[out] op Output buffer.
|
|
* @return Advanced "op" value.
|
|
* @tparam fltlen Filter length, in taps.
|
|
*/
|
|
|
|
template< int fltlen >
|
|
double* convolve0( double* op )
|
|
{
|
|
while( BufLeft > fl2 )
|
|
{
|
|
const double* const ftp = &(*FilterBank)[ InPosFracW ];
|
|
const double* const rp = Buf + ReadPos;
|
|
int i;
|
|
|
|
#if defined( R8B_SSE2 ) && !defined( __INTEL_COMPILER )
|
|
|
|
__m128d s = _mm_setzero_pd();
|
|
|
|
for( i = 0; i < fltlen; i += 2 )
|
|
{
|
|
const __m128d m = _mm_mul_pd( _mm_load_pd( ftp + i ),
|
|
_mm_loadu_pd( rp + i ));
|
|
|
|
s = _mm_add_pd( s, m );
|
|
}
|
|
|
|
_mm_storel_pd( op, _mm_add_pd( s, _mm_shuffle_pd( s, s, 1 )));
|
|
|
|
#elif defined( R8B_NEON )
|
|
|
|
float64x2_t s = vdupq_n_f64( 0.0 );
|
|
|
|
for( i = 0; i < fltlen; i += 2 )
|
|
{
|
|
s = vmlaq_f64( s, vld1q_f64( ftp + i ), vld1q_f64( rp + i ));
|
|
}
|
|
|
|
*op = vaddvq_f64( s );
|
|
|
|
#else // SIMD
|
|
|
|
double s = 0.0;
|
|
|
|
for( i = 0; i < fltlen; i++ )
|
|
{
|
|
s += ftp[ i ] * rp[ i ];
|
|
}
|
|
|
|
*op = s;
|
|
|
|
#endif // SIMD
|
|
|
|
op++;
|
|
|
|
InPosFracW += InStep;
|
|
const int PosIncr = InPosFracW / OutStep;
|
|
InPosFracW -= PosIncr * OutStep;
|
|
|
|
ReadPos = ( ReadPos + PosIncr ) & BufLenMask;
|
|
BufLeft -= PosIncr;
|
|
}
|
|
|
|
return( op );
|
|
}
|
|
|
|
/**
|
|
* Convolution function for 2nd order resampling.
|
|
*
|
|
* @param[out] op Output buffer.
|
|
* @return Advanced "op" value.
|
|
*/
|
|
|
|
double* convolve2( double* op )
|
|
{
|
|
const CDSPFracDelayFilterBank& fb = *FilterBank;
|
|
const int fltlen = FilterLen;
|
|
|
|
while( BufLeft > fl2 )
|
|
{
|
|
double x = InPosFrac * fb.getFilterFracs();
|
|
const int fti = (int) x; // Function table index.
|
|
x -= fti; // Coefficient for interpolation between
|
|
// adjacent fractional delay filters.
|
|
const double x2d = x * x;
|
|
const double* ftp = &fb[ fti ];
|
|
const double* const rp = Buf + ReadPos;
|
|
int i;
|
|
|
|
#if defined( R8B_SSE2 ) && defined( R8B_SIMD_ISH )
|
|
|
|
const __m128d x1 = _mm_set1_pd( x );
|
|
const __m128d x2 = _mm_set1_pd( x2d );
|
|
__m128d s = _mm_setzero_pd();
|
|
|
|
for( i = 0; i < fltlen; i += 2 )
|
|
{
|
|
const __m128d ftp2 = _mm_load_pd( ftp + 2 );
|
|
const __m128d xx1 = _mm_mul_pd( ftp2, x1 );
|
|
const __m128d ftp4 = _mm_load_pd( ftp + 4 );
|
|
const __m128d xx2 = _mm_mul_pd( ftp4, x2 );
|
|
const __m128d ftp0 = _mm_load_pd( ftp );
|
|
ftp += 6;
|
|
|
|
const __m128d rpi = _mm_loadu_pd( rp + i );
|
|
const __m128d xxs = _mm_add_pd( ftp0, _mm_add_pd( xx1, xx2 ));
|
|
|
|
s = _mm_add_pd( s, _mm_mul_pd( rpi, xxs ));
|
|
}
|
|
|
|
_mm_storel_pd( op, _mm_add_pd( s, _mm_shuffle_pd( s, s, 1 )));
|
|
|
|
#elif defined( R8B_NEON ) && defined( R8B_SIMD_ISH )
|
|
|
|
const float64x2_t x1 = vdupq_n_f64( x );
|
|
const float64x2_t x2 = vdupq_n_f64( x2d );
|
|
float64x2_t s = vdupq_n_f64( 0.0 );
|
|
|
|
for( i = 0; i < fltlen; i += 2 )
|
|
{
|
|
const float64x2_t ftp2 = vld1q_f64( ftp + 2 );
|
|
const float64x2_t xx1 = vmulq_f64( ftp2, x1 );
|
|
const float64x2_t ftp4 = vld1q_f64( ftp + 4 );
|
|
const float64x2_t xx2 = vmulq_f64( ftp4, x2 );
|
|
const float64x2_t ftp0 = vld1q_f64( ftp );
|
|
ftp += 6;
|
|
|
|
const float64x2_t rpi = vld1q_f64( rp + i );
|
|
const float64x2_t xxs = vaddq_f64( ftp0,
|
|
vaddq_f64( xx1, xx2 ));
|
|
|
|
s = vmlaq_f64( s, rpi, xxs );
|
|
}
|
|
|
|
*op = vaddvq_f64( s );
|
|
|
|
#else // SIMD
|
|
|
|
double s = 0.0;
|
|
|
|
for( i = 0; i < fltlen; i++ )
|
|
{
|
|
s += ( ftp[ 0 ] + ftp[ 1 ] * x + ftp[ 2 ] * x2d ) * rp[ i ];
|
|
ftp += 3;
|
|
}
|
|
|
|
*op = s;
|
|
|
|
#endif // SIMD
|
|
|
|
op++;
|
|
|
|
#if R8B_FASTTIMING
|
|
|
|
InPosFrac += FracStep;
|
|
const int PosIncr = (int) InPosFrac;
|
|
InPosFrac -= PosIncr;
|
|
|
|
#else // R8B_FASTTIMING
|
|
|
|
InCounter++;
|
|
const double NextInPos = ( InCounter + InPosShift ) *
|
|
SrcSampleRate / DstSampleRate;
|
|
|
|
const int NextInPosInt = (int) NextInPos;
|
|
const int PosIncr = NextInPosInt - InPosInt;
|
|
InPosInt = NextInPosInt;
|
|
InPosFrac = NextInPos - NextInPosInt;
|
|
|
|
#endif // R8B_FASTTIMING
|
|
|
|
ReadPos = ( ReadPos + PosIncr ) & BufLenMask;
|
|
BufLeft -= PosIncr;
|
|
}
|
|
|
|
return( op );
|
|
}
|
|
};
|
|
|
|
// ---------------------------------------------------------------------------
|
|
|
|
} // namespace r8b
|
|
|
|
#endif // R8B_CDSPFRACINTERPOLATOR_INCLUDED
|