/*
 * steghide 0.5.1 - a steganography program
 * Copyright (C) 1999-2003 Stefan Hetzl <shetzl@chello.at>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

#ifndef SH_JPEGFILE_H
#define SH_JPEGFILE_H

#include "common.h"

#include <vector>

extern "C" {
#include <jpeglib.h>
#include <stdio.h>
}

class BinaryIO;
#include "CvrStgFile.h"
class SampleValue;

/**
 * \class JpegFile
 * \brief a cover-/stego-file in the jpeg file format
 *
 * This class uses the JPEG library by the IJG for access to jpeg files.
 **/
class JpegFile : public CvrStgFile {
  public:
    JpegFile(BinaryIO *io);
    ~JpegFile(void);

    void read(BinaryIO *io);
    void write(void);

    std::list<CvrStgFile::Property> getProperties(void) const;
    std::vector<MatchingAlgorithm *> getMatchingAlgorithms(Graph *g, Matching *m) const;

    unsigned long getNumSamples(void) const;
    void replaceSample(const SamplePos pos, const SampleValue *s);
    SampleValue *getSampleValue(const SamplePos pos) const;
    EmbValue getEmbeddedValue(const SamplePos pos) const;

#ifdef DEBUG
    std::map<SampleKey, unsigned long> *getFrequencies(void);
    /**
     * SampleKey is unsigned, jpeg dct coefficients are signed data. This function is a
     *specialization of printFrequencies that converts the SampleKeys back to dct coefficient values
     *before printing them and also prints the values starting from the lowest (negative) and ending
     *with the highest (positive).
     **/
    void printFrequencies(const std::map<SampleKey, unsigned long> &freqs);
#endif

  private:
    /// the number of dct coefficients per block
    static const unsigned int CoeffPerBlock = 64;

    static const unsigned short SamplesPerVertex = 3;
    static const UWORD32 Radius = 1;
    static const EmbValue EmbValueModulus = 2;

    struct jpeg_compress_struct CInfo;
    struct jpeg_decompress_struct DeCInfo;
    unsigned int *HeightInBlocks;
    unsigned int *WidthInBlocks;
    jvirt_barray_ptr *DctCoeffs;

    std::vector<SWORD16> LinDctCoeffs;
    std::vector<UWORD32> StegoIndices;
};

#endif // ndef SH_JPEGFILE_H