643 lines
15 KiB
C
643 lines
15 KiB
C
![]() |
//$ nobt
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//$ nocpp
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/**
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* @file CDSPBlockConvolver.h
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*
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* @brief Single-block overlap-save convolution processor class.
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*
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* This file includes single-block overlap-save convolution processor 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_CDSPBLOCKCONVOLVER_INCLUDED
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#define R8B_CDSPBLOCKCONVOLVER_INCLUDED
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#include "CDSPFIRFilter.h"
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#include "CDSPProcessor.h"
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namespace r8b {
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/**
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* @brief Single-block overlap-save convolution processing class.
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*
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* Class that implements single-block overlap-save convolution processing. The
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* length of a single FFT block used depends on the length of the filter
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* kernel.
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*
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* The rationale behind "single-block" processing is that increasing the FFT
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* block length by 2 is more efficient than performing convolution at the same
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* FFT block length but using two blocks.
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*
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* This class also implements a built-in resampling by any whole-number
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* factor, which simplifies the overall resampling objects topology.
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*/
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class CDSPBlockConvolver : public CDSPProcessor
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{
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public:
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/**
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* Constructor initializes internal variables and constants of *this
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* object.
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*
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* @param aFilter Pre-calculated filter data. Reference to this object is
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* inhertied by *this object, and the object will be released when *this
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* object is destroyed. If upsampling is used, filter's gain should be
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* equal to the upsampling factor.
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* @param aUpFactor The upsampling factor, positive value. E.g. value of 2
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* means 2x upsampling should be performed over the input data.
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* @param aDownFactor The downsampling factor, positive value. E.g. value
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* of 2 means 2x downsampling should be performed over the output data.
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* @param PrevLatency Latency, in samples (any value >=0), which was left
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* in the output signal by a previous process. This value is usually
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* non-zero if the minimum-phase filters are in use. This value is always
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* zero if the linear-phase filters are in use.
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* @param aDoConsumeLatency "True" if the output latency should be
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* consumed. Does not apply to the fractional part of the latency (if such
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* part is available).
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*/
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CDSPBlockConvolver( CDSPFIRFilter& aFilter, const int aUpFactor,
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const int aDownFactor, const double PrevLatency = 0.0,
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const bool aDoConsumeLatency = true )
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: Filter( &aFilter )
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, UpFactor( aUpFactor )
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, DownFactor( aDownFactor )
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, DoConsumeLatency( aDoConsumeLatency )
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, BlockLen2( 2 << Filter -> getBlockLenBits() )
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{
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R8BASSERT( UpFactor > 0 );
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R8BASSERT( DownFactor > 0 );
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R8BASSERT( PrevLatency >= 0.0 );
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int fftinBits;
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UpShift = getBitOccupancy( UpFactor ) - 1;
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if(( 1 << UpShift ) == UpFactor )
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{
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fftinBits = Filter -> getBlockLenBits() + 1 - UpShift;
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PrevInputLen = ( Filter -> getKernelLen() - 1 + UpFactor - 1 ) /
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UpFactor;
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InputLen = BlockLen2 - PrevInputLen * UpFactor;
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}
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else
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{
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UpShift = -1;
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fftinBits = Filter -> getBlockLenBits() + 1;
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PrevInputLen = Filter -> getKernelLen() - 1;
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InputLen = BlockLen2 - PrevInputLen;
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}
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OutOffset = ( Filter -> isZeroPhase() ? Filter -> getLatency() : 0 );
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LatencyFrac = Filter -> getLatencyFrac() + PrevLatency * UpFactor;
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Latency = (int) LatencyFrac;
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const int InLatency = Latency + Filter -> getLatency() - OutOffset;
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LatencyFrac -= Latency;
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LatencyFrac /= DownFactor;
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Latency += InputLen + Filter -> getLatency();
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int fftoutBits;
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InputDelay = 0;
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DownSkipInit = 0;
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DownShift = getBitOccupancy( DownFactor ) - 1;
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if(( 1 << DownShift ) == DownFactor )
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{
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fftoutBits = Filter -> getBlockLenBits() + 1 - DownShift;
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if( DownFactor > 1 )
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{
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if( UpShift > 0 )
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{
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// This case never happens in practice due to mutual
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// exclusion of "power of 2" DownFactor and UpFactor
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// values.
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R8BASSERT( UpShift == 0 );
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}
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else
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{
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// Make sure InputLen is divisible by DownFactor.
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const int ilc = InputLen & ( DownFactor - 1 );
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PrevInputLen += ilc;
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InputLen -= ilc;
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Latency -= ilc;
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// Correct InputDelay for input and filter's latency.
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const int lc = InLatency & ( DownFactor - 1 );
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if( lc > 0 )
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{
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InputDelay = DownFactor - lc;
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}
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if( !DoConsumeLatency )
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{
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Latency /= DownFactor;
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}
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}
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}
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}
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else
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{
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fftoutBits = Filter -> getBlockLenBits() + 1;
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DownShift = -1;
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if( !DoConsumeLatency && DownFactor > 1 )
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{
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DownSkipInit = Latency % DownFactor;
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Latency /= DownFactor;
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}
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}
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R8BASSERT( Latency >= 0 );
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fftin = new CDSPRealFFTKeeper( fftinBits );
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if( fftoutBits == fftinBits )
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{
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fftout = fftin;
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}
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else
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{
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ffto2 = new CDSPRealFFTKeeper( fftoutBits );
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fftout = ffto2;
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}
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WorkBlocks.alloc( BlockLen2 * 2 + PrevInputLen );
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CurInput = &WorkBlocks[ 0 ];
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CurOutput = &WorkBlocks[ BlockLen2 ]; // CurInput and
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// CurOutput are address-aligned.
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PrevInput = &WorkBlocks[ BlockLen2 * 2 ];
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clear();
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R8BCONSOLE( "CDSPBlockConvolver: flt_len=%i in_len=%i io=%i/%i "
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"fft=%i/%i latency=%i\n", Filter -> getKernelLen(), InputLen,
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UpFactor, DownFactor, (*fftin) -> getLen(), (*fftout) -> getLen(),
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getLatency() );
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}
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virtual ~CDSPBlockConvolver()
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{
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Filter -> unref();
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}
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virtual int getLatency() const
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{
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return( DoConsumeLatency ? 0 : Latency );
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}
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virtual double getLatencyFrac() const
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{
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return( LatencyFrac );
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}
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virtual int getMaxOutLen( const int MaxInLen ) const
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{
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R8BASSERT( MaxInLen >= 0 );
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return(( MaxInLen * UpFactor + DownFactor - 1 ) / DownFactor );
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}
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virtual void clear()
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{
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memset( &PrevInput[ 0 ], 0, PrevInputLen * sizeof( PrevInput[ 0 ]));
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if( DoConsumeLatency )
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{
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LatencyLeft = Latency;
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}
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else
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{
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LatencyLeft = 0;
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if( DownShift > 0 )
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{
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memset( &CurOutput[ 0 ], 0, ( BlockLen2 >> DownShift ) *
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sizeof( CurOutput[ 0 ]));
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}
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else
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{
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memset( &CurOutput[ BlockLen2 - OutOffset ], 0, OutOffset *
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sizeof( CurOutput[ 0 ]));
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memset( &CurOutput[ 0 ], 0, ( InputLen - OutOffset ) *
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sizeof( CurOutput[ 0 ]));
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}
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}
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memset( CurInput, 0, InputDelay * sizeof( CurInput[ 0 ]));
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InDataLeft = InputLen - InputDelay;
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UpSkip = 0;
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DownSkip = DownSkipInit;
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}
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virtual int process( double* ip, int l0, double*& op0 )
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{
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R8BASSERT( l0 >= 0 );
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R8BASSERT( UpFactor / DownFactor <= 1 || ip != op0 || l0 == 0 );
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double* op = op0;
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int l = l0 * UpFactor;
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l0 = 0;
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while( l > 0 )
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{
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const int Offs = InputLen - InDataLeft;
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if( l < InDataLeft )
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{
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InDataLeft -= l;
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if( UpShift >= 0 )
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{
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memcpy( &CurInput[ Offs >> UpShift ], ip,
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( l >> UpShift ) * sizeof( CurInput[ 0 ]));
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}
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else
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{
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copyUpsample( ip, &CurInput[ Offs ], l );
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}
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copyToOutput( Offs - OutOffset, op, l, l0 );
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break;
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}
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const int b = InDataLeft;
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l -= b;
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InDataLeft = InputLen;
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int ilu;
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if( UpShift >= 0 )
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{
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const int bu = b >> UpShift;
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memcpy( &CurInput[ Offs >> UpShift ], ip,
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bu * sizeof( CurInput[ 0 ]));
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ip += bu;
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ilu = InputLen >> UpShift;
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}
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else
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{
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copyUpsample( ip, &CurInput[ Offs ], b );
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ilu = InputLen;
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}
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const size_t pil = PrevInputLen * sizeof( CurInput[ 0 ]);
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memcpy( &CurInput[ ilu ], PrevInput, pil );
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memcpy( PrevInput, &CurInput[ ilu - PrevInputLen ], pil );
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(*fftin) -> forward( CurInput );
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if( UpShift > 0 )
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{
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#if R8B_FLOATFFT
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mirrorInputSpectrum( (float*) CurInput );
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#else // R8B_FLOATFFT
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mirrorInputSpectrum( CurInput );
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#endif // R8B_FLOATFFT
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}
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if( Filter -> isZeroPhase() )
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{
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(*fftout) -> multiplyBlocksZP( Filter -> getKernelBlock(),
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CurInput );
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}
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else
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{
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(*fftout) -> multiplyBlocks( Filter -> getKernelBlock(),
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CurInput );
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}
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if( DownShift > 0 )
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{
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const int z = BlockLen2 >> DownShift;
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#if R8B_FLOATFFT
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float* const kb = (float*) Filter -> getKernelBlock();
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float* const p = (float*) CurInput;
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#else // R8B_FLOATFFT
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const double* const kb = Filter -> getKernelBlock();
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double* const p = CurInput;
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#endif // R8B_FLOATFFT
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p[ 1 ] = kb[ z ] * p[ z ] - kb[ z + 1 ] * p[ z + 1 ];
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}
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(*fftout) -> inverse( CurInput );
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copyToOutput( Offs - OutOffset, op, b, l0 );
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double* const tmp = CurInput;
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CurInput = CurOutput;
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CurOutput = tmp;
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}
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return( l0 );
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}
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private:
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CDSPFIRFilter* Filter; ///< Filter in use.
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///<
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CPtrKeeper< CDSPRealFFTKeeper* > fftin; ///< FFT object 1, used to produce
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///< the input spectrum (can embed the "power of 2" upsampling).
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///<
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CPtrKeeper< CDSPRealFFTKeeper* > ffto2; ///< FFT object 2 (can be NULL).
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///<
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CDSPRealFFTKeeper* fftout; ///< FFT object used to produce the output
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///< signal (can embed the "power of 2" downsampling), may point to
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///< either "fftin" or "ffto2".
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///<
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int UpFactor; ///< Upsampling factor.
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///<
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int DownFactor; ///< Downsampling factor.
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///<
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bool DoConsumeLatency; ///< "True" if the output latency should be
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///< consumed. Does not apply to the fractional part of the latency
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///< (if such part is available).
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///<
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int BlockLen2; ///< Equals block length * 2.
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///<
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int OutOffset; ///< Output offset, depends on filter's introduced latency.
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///<
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int PrevInputLen; ///< The length of previous input data saved, used for
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///< overlap.
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///<
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int InputLen; ///< The number of input samples that should be accumulated
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///< before the input block is processed.
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///<
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int Latency; ///< Processing latency, in samples.
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///<
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double LatencyFrac; ///< Fractional latency, in samples, that is left in
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///< the output signal.
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///<
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int UpShift; ///< "Power of 2" upsampling shift. Equals -1 if UpFactor is
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///< not a "power of 2" value. Equals 0 if UpFactor equals 1.
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///<
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int DownShift; ///< "Power of 2" downsampling shift. Equals -1 if
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///< DownFactor is not a "power of 2". Equals 0 if DownFactor equals
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///< 1.
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///<
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int InputDelay; ///< Additional input delay, in samples. Used to make the
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///< output delay divisible by DownShift. Used only if UpShift <= 0
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///< and DownShift > 0.
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///<
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CFixedBuffer< double > WorkBlocks; ///< Previous input data, input and
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///< output data blocks, overall capacity = BlockLen2 * 2 +
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///< PrevInputLen. Used in the flip-flop manner.
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///<
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double* PrevInput; ///< Previous input data buffer, capacity = BlockLen.
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///<
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double* CurInput; ///< Input data buffer, capacity = BlockLen2.
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///<
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double* CurOutput; ///< Output data buffer, capacity = BlockLen2.
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///<
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int InDataLeft; ///< Samples left before processing input and output FFT
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///< blocks. Initialized to InputLen on clear.
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///<
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int LatencyLeft; ///< Latency in samples left to skip.
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///<
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int UpSkip; ///< The current upsampling sample skip (value in the range
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///< 0 to UpFactor - 1).
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///<
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int DownSkip; ///< The current downsampling sample skip (value in the
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///< range 0 to DownFactor - 1). Not used if DownShift > 0.
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///<
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int DownSkipInit; ///< The initial DownSkip value after clear().
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///<
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/**
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* Function copies samples from the input buffer to the output buffer
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* while inserting zeros inbetween them to perform the whole-numbered
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* upsampling.
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*
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* @param[in,out] ip0 Input buffer. Will be advanced on function's return.
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* @param[out] op Output buffer.
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* @param l0 The number of samples to fill in the output buffer, including
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* both input samples and interpolation (zero) samples.
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*/
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void copyUpsample( double*& ip0, double* op, int l0 )
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{
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int b = min( UpSkip, l0 );
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if( b != 0 )
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{
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UpSkip -= b;
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l0 -= b;
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*op = 0.0;
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op++;
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while( --b != 0 )
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{
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*op = 0.0;
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op++;
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}
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}
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double* ip = ip0;
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const int upf = UpFactor;
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int l = l0 / upf;
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int lz = l0 - l * upf;
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if( upf == 3 )
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{
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while( l != 0 )
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{
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op[ 0 ] = *ip;
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op[ 1 ] = 0.0;
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||
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op[ 2 ] = 0.0;
|
||
|
ip++;
|
||
|
op += upf;
|
||
|
l--;
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
if( upf == 5 )
|
||
|
{
|
||
|
while( l != 0 )
|
||
|
{
|
||
|
op[ 0 ] = *ip;
|
||
|
op[ 1 ] = 0.0;
|
||
|
op[ 2 ] = 0.0;
|
||
|
op[ 3 ] = 0.0;
|
||
|
op[ 4 ] = 0.0;
|
||
|
ip++;
|
||
|
op += upf;
|
||
|
l--;
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
const size_t zc = ( upf - 1 ) * sizeof( op[ 0 ]);
|
||
|
|
||
|
while( l != 0 )
|
||
|
{
|
||
|
*op = *ip;
|
||
|
ip++;
|
||
|
|
||
|
memset( op + 1, 0, zc );
|
||
|
op += upf;
|
||
|
l--;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if( lz != 0 )
|
||
|
{
|
||
|
*op = *ip;
|
||
|
ip++;
|
||
|
op++;
|
||
|
|
||
|
UpSkip = upf - lz;
|
||
|
|
||
|
while( --lz != 0 )
|
||
|
{
|
||
|
*op = 0.0;
|
||
|
op++;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
ip0 = ip;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Function copies sample data from the CurOutput buffer to the specified
|
||
|
* output buffer and advances its position. If necessary, this function
|
||
|
* "consumes" latency and performs downsampling.
|
||
|
*
|
||
|
* @param Offs CurOutput buffer offset, can be negative.
|
||
|
* @param[out] op0 Output buffer pointer, will be advanced.
|
||
|
* @param b The number of output samples available, including those which
|
||
|
* are discarded during whole-number downsampling.
|
||
|
* @param l0 The overall output sample count, will be increased.
|
||
|
*/
|
||
|
|
||
|
void copyToOutput( int Offs, double*& op0, int b, int& l0 )
|
||
|
{
|
||
|
if( Offs < 0 )
|
||
|
{
|
||
|
if( Offs + b <= 0 )
|
||
|
{
|
||
|
Offs += BlockLen2;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
copyToOutput( Offs + BlockLen2, op0, -Offs, l0 );
|
||
|
b += Offs;
|
||
|
Offs = 0;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if( LatencyLeft != 0 )
|
||
|
{
|
||
|
if( LatencyLeft >= b )
|
||
|
{
|
||
|
LatencyLeft -= b;
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
Offs += LatencyLeft;
|
||
|
b -= LatencyLeft;
|
||
|
LatencyLeft = 0;
|
||
|
}
|
||
|
|
||
|
const int df = DownFactor;
|
||
|
|
||
|
if( DownShift > 0 )
|
||
|
{
|
||
|
int Skip = Offs & ( df - 1 );
|
||
|
|
||
|
if( Skip > 0 )
|
||
|
{
|
||
|
Skip = df - Skip;
|
||
|
b -= Skip;
|
||
|
Offs += Skip;
|
||
|
}
|
||
|
|
||
|
if( b > 0 )
|
||
|
{
|
||
|
b = ( b + df - 1 ) >> DownShift;
|
||
|
memcpy( op0, &CurOutput[ Offs >> DownShift ],
|
||
|
b * sizeof( op0[ 0 ]));
|
||
|
|
||
|
op0 += b;
|
||
|
l0 += b;
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
if( df > 1 )
|
||
|
{
|
||
|
const double* ip = &CurOutput[ Offs + DownSkip ];
|
||
|
int l = ( b + df - 1 - DownSkip ) / df;
|
||
|
DownSkip += l * df - b;
|
||
|
|
||
|
double* op = op0;
|
||
|
l0 += l;
|
||
|
op0 += l;
|
||
|
|
||
|
while( l > 0 )
|
||
|
{
|
||
|
*op = *ip;
|
||
|
ip += df;
|
||
|
op++;
|
||
|
l--;
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
memcpy( op0, &CurOutput[ Offs ], b * sizeof( op0[ 0 ]));
|
||
|
op0 += b;
|
||
|
l0 += b;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Function performs input spectrum mirroring which is used to perform a
|
||
|
* fast "power of 2" upsampling. Such mirroring is equivalent to insertion
|
||
|
* of zeros into the input signal.
|
||
|
*
|
||
|
* @param p Spectrum data block to mirror.
|
||
|
* @tparam T Buffer's element type.
|
||
|
*/
|
||
|
|
||
|
template< typename T >
|
||
|
void mirrorInputSpectrum( T* const p )
|
||
|
{
|
||
|
const int bl1 = BlockLen2 >> UpShift;
|
||
|
const int bl2 = bl1 + bl1;
|
||
|
int i;
|
||
|
|
||
|
for( i = bl1 + 2; i < bl2; i += 2 )
|
||
|
{
|
||
|
p[ i ] = p[ bl2 - i ];
|
||
|
p[ i + 1 ] = -p[ bl2 - i + 1 ];
|
||
|
}
|
||
|
|
||
|
p[ bl1 ] = p[ 1 ];
|
||
|
p[ bl1 + 1 ] = 0.0;
|
||
|
p[ 1 ] = p[ 0 ];
|
||
|
|
||
|
for( i = 1; i < UpShift; i++ )
|
||
|
{
|
||
|
const int z = bl1 << i;
|
||
|
memcpy( &p[ z ], p, z * sizeof( p[ 0 ]));
|
||
|
p[ z + 1 ] = 0.0;
|
||
|
}
|
||
|
}
|
||
|
};
|
||
|
|
||
|
} // namespace r8b
|
||
|
|
||
|
#endif // R8B_CDSPBLOCKCONVOLVER_INCLUDED
|