plonk_IFFTChannel.h

/*
 -------------------------------------------------------------------------------
 This file is part of the Plink, Plonk, Plank libraries
  by Martin Robinson
 
 http://code.google.com/p/pl-nk/
 
 Copyright University of the West of England, Bristol 2011-14
 All rights reserved.
 
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 * Redistributions of source code must retain the above copyright
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 * Redistributions in binary form must reproduce the above copyright
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   documentation and/or other materials provided with the distribution.
 * Neither the name of University of the West of England, Bristol nor 
   the names of its contributors may be used to endorse or promote products
   derived from this software without specific prior written permission.
 
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 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
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 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 
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 This software makes use of third party libraries. For more information see:
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 -------------------------------------------------------------------------------
 */

#ifndef PLONK_IFFTCHANNEL_H
#define PLONK_IFFTCHANNEL_H

#include "../channel/plonk_ChannelInternalCore.h"
#include "../plonk_GraphForwardDeclarations.h"

//template<class SampleType>
//class IFFTChannelInternal 
//:   public ChannelInternal<SampleType, ChannelInternalCore::Data>
//{
//public:
//    typedef ChannelInternalCore::Data                           Data;
//    typedef ChannelBase<SampleType>                             ChannelType;
//    typedef IFFTChannelInternal<SampleType>                     IFFTInternal;
//    typedef ChannelInternal<SampleType,Data>                    Internal;
//    typedef ChannelInternalBase<SampleType>                     InternalBase;
//    typedef UnitBase<SampleType>                                UnitType;
//    typedef InputDictionary                                     Inputs;
//    typedef NumericalArray<SampleType>                          Buffer;
//    typedef FFTEngineBase<SampleType>                           FFTEngineType;
//        
//    IFFTChannelInternal (Inputs const& inputs, 
//                         Data const& data, 
//                         BlockSize const& blockSize,
//                         SampleRate const& sampleRate) throw()
//    :   Internal (inputs, data, blockSize, sampleRate)
//    {
//    }
//    
//    Text getName() const throw()
//    {        
//        return "IFFT";
//    }        
//    
//    IntArray getInputKeys() const throw()
//    {
//        const IntArray keys (IOKey::FFT);
//        return keys;
//    }    
//    
//    InternalBase* getChannel (const int /*index*/) throw()
//    {
//        return this; /// ? could create "this" with pairs but no need at the moment
//    }        
//    
//    void initChannel (const int /*channel*/) throw()
//    {
//        const UnitType& input = this->getInputAsUnit (IOKey::FFT);
//        
//        // check for channel  an channel + 1 on the input?
//        
//        this->setBlockSize (input.getBlockSize (0));
//        this->setSampleRate (input.getSampleRate (0));    
//        this->setOverlap (input.getOverlap (0));    
//        
//        this->fft = FFTEngineType (input.getBlockSize (0));
//        
//        this->initValue (SampleType (0)); // impossible to precalculate
//    }    
//            
//    void process (ProcessInfo& info, const int channel) throw()
//    {               
//        /* Be careful optimising this with the new NumericalArray vector stuff */
//
//        const int realIndex = channel * 2;
//        const int imagIndex = realIndex + 1;
//        
//        UnitType& inputUnit (this->getInputAsUnit (IOKey::FFT));
//        const Buffer& realBuffer (inputUnit.process (info, realIndex));
//        const Buffer& imagBuffer (inputUnit.process (info, imagIndex));
//        
//        plonk_assert (realBuffer.length() == imagBuffer.length());
//        
//        const SampleType* const realInputSamples = realBuffer.getArray();
//        const SampleType* const imagInputSamples = imagBuffer.getArray();
//        
//        SampleType* const outputSamples = this->getOutputSamples();
//        const int outputBufferLength = this->getOutputBuffer().length();
//        
//        plonk_assert (outputBufferLength == realBuffer.length());
//        
//        if (outputBufferLength != this->fft.length())
//            this->fft = FFTEngineType (outputBufferLength);
//                
//        const long halfLength = this->fft.halfLength();
//
//        // pack
//        int i, j;
//                
//        for (i = 0; i <= halfLength; ++i)
//            outputSamples[i] = realInputSamples[i];
//
//        for (j = 1; i < outputBufferLength; ++i, ++j)
//            outputSamples[i] = imagInputSamples[j];
//        
//        // transform
//        this->fft.inverse (outputSamples, outputSamples); // in-place
//    }
//
//private:
//    FFTEngineType fft;
//};
//
//
//
//
// Takes frequency domain signal in real/imaginary format and outputs the time domain real signal. 
// 
// Each pair of imput channels generates one output channel. The even numbered channels should conatin 
// the real data and the odd numbered channel should contain the imaginary data. (This is the same
// output format as the FFTUnit.)
// 
// @par Factory functions:
// - ar (input)
// 
// @par Inputs:
// - input: (unit, multi, fft) the input unit in FFT format
// 
//
// @ingroup ConverterUnits FFTUnits */
//template<class SampleType>
//class IFFTUnit
//{
//public:    
//    typedef IFFTChannelInternal<SampleType>         IFFTInternal;
//    typedef typename IFFTInternal::Data             Data;
//    typedef ChannelBase<SampleType>                 ChannelType;
//    typedef ChannelInternal<SampleType,Data>        Internal;
//    typedef ChannelInternalBase<SampleType>         InternalBase;
//    typedef UnitBase<SampleType>                    UnitType;
//    typedef InputDictionary                         Inputs;
//    typedef NumericalArray<SampleType>              Buffer;
//    
//    static inline UnitInfos getInfo() throw()
//    {
//        return UnitInfo ("IFFT", "Transforms  frequency domain data to a time domain signal.",
//                         
//                         // output
//                         1, 
//                         IOKey::Generic,  Measure::None,      IOInfo::NoDefault,  IOLimit::None, 
//                         IOKey::End,
//                         
//                         // inputs
//                         IOKey::FFT,     Measure::None,
//                         IOKey::End);
//    }    
//    
//    /** IFFTs a signal. */
//    static inline UnitType ar (UnitType const& input) throw()
//    {        
//        // re: full templating - could say that FFT/IFTT are only supported with float (and eventually double)?
//
//        plonk_assert ((input.getNumChannels() % 2) == 0); // must be real and imag pairs
//        
//        // need to put these asserts in the initChannel
//        
//        const int numOutputChannels = input.getNumChannels() / 2;
//        plonk_assert (numOutputChannels > 0);
//        
//        UnitType result (UnitType::emptyWithAllocatedSize (numOutputChannels));
//        Data data = { -1.0, -1.0 };
//        
//        for (int i = 0; i < numOutputChannels; ++i)
//        {
//            UnitType pair (UnitType::emptyWithAllocatedSize (2)); 
//            pair.add (input[i * 2]);
//            pair.add (input[i * 2 + 1]);
//            
//            Inputs inputs;
//            inputs.put (IOKey::FFT, pair);
//                        
//            InternalBase* internal = new IFFTInternal (inputs, 
//                                                       data, 
//                                                       BlockSize::noPreference(), 
//                                                       SampleRate::noPreference());            
//            internal->initChannel (i);
//            
//            result.add (ChannelType (internal));
//        }
//        
//        return result;
//        
//    }
//};

template<class SampleType>
class IFFTChannelInternal
:   public ChannelInternal<SampleType, ChannelInternalCore::Data>
{
public:
    typedef ChannelInternalCore::Data                           Data;
    typedef ChannelBase<SampleType>                             ChannelType;
    typedef IFFTChannelInternal<SampleType>                     IFFTInternal;
    typedef ChannelInternal<SampleType,Data>                    Internal;
    typedef ChannelInternalBase<SampleType>                     InternalBase;
    typedef UnitBase<SampleType>                                UnitType;
    typedef InputDictionary                                     Inputs;
    typedef NumericalArray<SampleType>                          Buffer;
    typedef FFTEngineBase<SampleType>                           FFTEngineType;
    
    IFFTChannelInternal (Inputs const& inputs,
                         Data const& data,
                         BlockSize const& blockSize,
                         SampleRate const& sampleRate) throw()
    :   Internal (inputs, data, blockSize, sampleRate)
    {
    }
    
    Text getName() const throw()
    {
        return "IFFT";
    }
    
    IntArray getInputKeys() const throw()
    {
        const IntArray keys (IOKey::FFTPacked);
        return keys;
    }
    
    InternalBase* getChannel (const int index) throw()
    {
        const Inputs channelInputs = this->getInputs().getChannel (index);
        return new IFFTInternal (channelInputs,
                                 this->getState(),
                                 this->getBlockSize(),
                                 this->getSampleRate());
    }
    
    void initChannel (const int channel) throw()
    {
        const UnitType& input = this->getInputAsUnit (IOKey::FFTPacked);
                
        this->setBlockSize (input.getBlockSize (channel));
        this->setSampleRate (input.getSampleRate (channel));
        this->setOverlap (input.getOverlap (channel));
        
        this->fft = FFTEngineType (input.getBlockSize (channel));
        
        this->initValue (SampleType (0)); // impossible to precalculate
    }
    
    void process (ProcessInfo& info, const int channel) throw()
    {
        /* Be careful optimising this with the new NumericalArray vector stuff */
                
        UnitType& inputUnit (this->getInputAsUnit (IOKey::FFTPacked));
        const Buffer& inputBuffer (inputUnit.process (info, channel));
        const SampleType* const inputSamples = inputBuffer.getArray();
        
        SampleType* const outputSamples = this->getOutputSamples();
        const int outputBufferLength = this->getOutputBuffer().length();
        
        plonk_assert (outputBufferLength == inputBuffer.length());
        
        if (outputBufferLength != this->fft.length())
            this->fft = FFTEngineType (outputBufferLength);
            
        this->fft.inverse (outputSamples, inputSamples); // in-place
    }
    
private:
    FFTEngineType fft;
};



//------------------------------------------------------------------------------

template<class SampleType>
class IFFTUnit
{
public:
    typedef IFFTChannelInternal<SampleType>         IFFTInternal;
    typedef typename IFFTInternal::Data             Data;
    typedef ChannelBase<SampleType>                 ChannelType;
    typedef ChannelInternal<SampleType,Data>        Internal;
    typedef ChannelInternalBase<SampleType>         InternalBase;
    typedef UnitBase<SampleType>                    UnitType;
    typedef InputDictionary                         Inputs;
    typedef NumericalArray<SampleType>              Buffer;
    
    static inline UnitInfos getInfo() throw()
    {
        return UnitInfo ("IFFT", "Transforms  frequency domain data to a time domain signal.",
                         
                         // output
                         ChannelCount::VariableChannelCount,
                         IOKey::Generic,       Measure::None,        IOInfo::NoDefault,  IOLimit::None,
                         IOKey::End,
                         
                         // inputs
                         IOKey::FFTPacked,     Measure::FFTPacked,   IOInfo::NoDefault,  IOLimit::None,
                         IOKey::End);
    }
        
    static inline UnitType ar (UnitType const& input) throw()
    {
        // re: full templating - could say that FFT/IFFT are only supported with float (and eventually double)?
        
        Inputs inputs;
        inputs.put (IOKey::FFTPacked, input);
        
        Data data = { -1.0, -1.0 };
        
        return UnitType::template createFromInputs<IFFTInternal> (inputs,
                                                                  data,
                                                                  BlockSize::noPreference(),
                                                                  SampleRate::noPreference());
    }

};


typedef IFFTUnit<PLONK_TYPE_DEFAULT> IFFT;

#endif // PLONK_IFFTCHANNEL_H