visual_stimulus.cpp

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#include "visual_stimulus.h"

#include <poisson_rate.h>
#include <string>
#include <cassert> // assert
#include <stdio.h> // fopen, fread, fclose
#include <stdlib.h> // exit

class VisualStimulus::Impl {
public:
    // +++++ PUBLIC METHODS +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ //

    Impl(std::string fileName, bool wrapAroundEOF) {
        _fileId = NULL;
        _fileName = fileName;
        _wrapAroundEOF = wrapAroundEOF;

        _frame = NULL;
        _frameNum = -1;

        _width = -1;
        _height = -1;
        _length = -1;

        _framePoisson = NULL;

        _channels = -1;
        _type = UNKNOWN_STIM;

        _version = 1.0f;
        _fileSignature = 293390619; // v1.0 file signature

        // read the header section of the binary file
        readHeader();
    }

    ~Impl() {
        if (_frame!=NULL)
            delete[] _frame;
        _frame=NULL;

        if (_framePoisson!=NULL)
            delete _framePoisson;
        _framePoisson=NULL;

        if (_fileId!=NULL)
            fclose(_fileId);
    }

    // reads the next frame and returns the char array
    unsigned char* readFrameChar() {
        readFramePrivate();
        return _frame;
    }

    // reads the next frame and returns the PoissonRate object
    PoissonRate* readFramePoisson(float maxPoisson, float minPoisson) {
        assert(maxPoisson>0);
        assert(maxPoisson>minPoisson);

        // read next frame
        readFramePrivate();

        // create new Poisson object, assign 
        _framePoisson = new PoissonRate(_width*_height*_channels);
        for (int i=0; i<_width*_height*_channels; i++) {
            _framePoisson->setRate(i, _frame[i]*(maxPoisson-minPoisson)/255.0f + minPoisson); // scale firing rates
        }
        
        return _framePoisson;
    }

    // rewind position of file stream to first frame
    void rewind() {
        fseek(_fileId, _fileHeaderSizeBytes, SEEK_SET);
    }

    void print() {
        fprintf(stdout, "VisualStimulus loaded (\"%s\", Type %d, Size %dx%dx%dx%d).\n", _fileName.c_str(), _type, 
            _width, _height, _channels, _length);
    }

    int getWidth()  { return _width; }
    int getHeight() { return _height; }
    int getLength() { return _length; }
    int getChannels() { return _channels; }
    stimType_t getType() { return _type; }

    unsigned char* getCurrentFrameChar() { return _frame; }
    PoissonRate* getCurrentFramePoisson() { return _framePoisson; }
    int getCurrentFrameNumber() { return _frameNum; }


private:
    // +++++ PRIVATE METHODS ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ //

    // reads next frame and assigns char array and Poisson Rate
    void readFramePrivate() {
        // make sure type is set
        assert(_type!=UNKNOWN_STIM);

        // keep at most one frame in memory
        if (_frame!=NULL)
            delete[] _frame;
        if (_framePoisson!=NULL)
            delete _framePoisson;
        _frame = NULL; _framePoisson = NULL;

        // have we reached EOF?
        if (feof(_fileId) || (_frameNum==_length-1)) {
            // reset frame index
            _frameNum = -1;

            if (!_wrapAroundEOF) {
                // we've reached end of file, print a warning
                fprintf(stderr,"WARNING: End of file reached, starting from the top\n");
            }

            // rewind position of file stream to first frame
            rewind();
        }

        // read new frame
        _frame = new unsigned char[_width*_height*_channels];
        size_t result = fread(_frame, sizeof(unsigned char), _width*_height*_channels, _fileId);
        if (result!=(size_t) (_width*_height*_channels)) {
            fprintf(stderr,"VisualStimulus Error: Error while reading stimulus frame (expected %d elements, found %d\n",
                _width*_height*_channels, (int)result);
            exit(1);
        }

        // initialized as -1, so after reading first frame this sits at 0
        _frameNum++;
    }

    // reads the header section of the binary file
    void readHeader() {
        _fileId = fopen(_fileName.c_str(),"rb");
        if (_fileId==NULL) {
            fprintf(stderr,"VisualStimulus Error: Could not open stimulus file %s\n",_fileName.c_str());
            exit(1);
        }

        bool readErr = false; // keep track of reading Errors
        size_t result;
        int tmpInt;
        float tmpFloat;
        char tmpChar;

        // read signature
        result = fread(&tmpInt, sizeof(int), 1, _fileId);
        readErr |= (result!=1);
        if (tmpInt != _fileSignature) {
            fprintf(stderr,"VisualStimulus Error: Unknown file signature\n");
            exit(1);
        }

        // read version number
        result = fread(&tmpFloat, sizeof(float), 1, _fileId);
        readErr |= (result!=1);
        if (tmpFloat != _version) {
            fprintf(stderr,"VisualStimulus Error: Unknown file version (%1.1f), must have 1.0\n",tmpFloat);
            exit(1);
        }

        // read stimulus type
        result = fread(&tmpInt, sizeof(int), 1, _fileId);
        readErr |= (result!=1);
        if (tmpInt < UNKNOWN_STIM || tmpInt > COMPOUND_STIM) {
            fprintf(stderr,"VisualStimulus Error: Unknown stimulus type found (%d)\n",tmpInt);
            exit(1);
        }
        _type = static_cast<stimType_t>(tmpInt);

        // read number of channels
        result = fread(&tmpChar, sizeof(char), 1, _fileId);
        readErr |= (result!=1);
        _channels = (int)tmpChar;

        // read stimulus dimensions
        result = fread(&tmpInt, sizeof(int), 1, _fileId);       readErr |= (result!=1);
        _width = tmpInt;
        result = fread(&tmpInt, sizeof(int), 1, _fileId);       readErr |= (result!=1);
        _height = tmpInt;
        result = fread(&tmpInt, sizeof(int), 1, _fileId);       readErr |= (result!=1);
        _length = tmpInt;

        // any reading Errors encountered?
        if (readErr) {
            fprintf(stderr,"VisualStimulus Error: Error while reading file %s\n",_fileName.c_str());
            exit(1);
        }

        // store the size of the header section (in bytes)
        _fileHeaderSizeBytes = ftell(_fileId);
    }


    // +++++ PRIVATE MEMBERS ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ //

    FILE* _fileId;              
    std::string _fileName;      

    int _version;               
    int _fileSignature;         

    long _fileHeaderSizeBytes;  
    bool _wrapAroundEOF;        

    unsigned char* _frame;      
    int _frameNum;              

    PoissonRate* _framePoisson; 

    int _width;                 
    int _height;                
    int _length;                

    int _channels;              
    stimType_t _type;           
};


// ****************************************************************************************************************** //
// VISUALSTIMULUS API IMPLEMENTATION
// ****************************************************************************************************************** //

// create and destroy a pImpl instance
VisualStimulus::VisualStimulus(std::string fileName, bool wrapAroundEOF) : _impl( new Impl(fileName, wrapAroundEOF) ) {}
VisualStimulus::~VisualStimulus() { delete _impl; }

unsigned char* VisualStimulus::readFrameChar() { return _impl->readFrameChar(); }
PoissonRate* VisualStimulus::readFramePoisson(float maxPoisson, float minPoisson) {
    return _impl->readFramePoisson(maxPoisson, minPoisson);
}
void VisualStimulus::rewind() { _impl->rewind(); }
void VisualStimulus::print() { _impl->print(); }

int VisualStimulus::getWidth() { return _impl->getWidth(); }
int VisualStimulus::getHeight() { return _impl->getHeight(); }
int VisualStimulus::getLength() { return _impl->getLength(); }
int VisualStimulus::getChannels() { return _impl->getChannels(); }
stimType_t VisualStimulus::getType() { return _impl->getType(); }
unsigned char* VisualStimulus::getCurrentFrameChar() { return _impl->getCurrentFrameChar(); }
PoissonRate* VisualStimulus::getCurrentFramePoisson() { return _impl->getCurrentFramePoisson(); }
int VisualStimulus::getCurrentFrameNumber() { return _impl->getCurrentFrameNumber(); }