68 lines
2.5 KiB
C++
68 lines
2.5 KiB
C++
/*
|
|
* 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_CVRSTGOBJECT_H
|
|
#define SH_CVRSTGOBJECT_H
|
|
|
|
#include "common.h"
|
|
|
|
class SampleValue ;
|
|
|
|
/**
|
|
* \class CvrStgObject
|
|
* \brief an object that can hold embedded data
|
|
*
|
|
* This abstract base class provides an interface for every class that is able
|
|
* to hold embedded data. Something that can hold embedded data is essentially
|
|
* though of as an array of samples.
|
|
*
|
|
* Definitions:
|
|
* Embedded Bit...a bit to be embedded (one bit in the original or extracted embfile)
|
|
* Sample...the smallest data unit in a file (e.g. a RGB triple, a DCT coefficient)
|
|
**/
|
|
class CvrStgObject {
|
|
public:
|
|
/**
|
|
* get the number of samples in this CvrStgObject
|
|
**/
|
|
virtual unsigned long getNumSamples (void) const = 0 ;
|
|
|
|
/**
|
|
* get the sample at position pos
|
|
* \param pos the position of a sample (must be in 0...getNumSamples()-1)
|
|
* \return the sample at the given position
|
|
*
|
|
* The sample object is created in this function and should be deleted by the caller.
|
|
* The derived class should check the condition(s) given above in its Implementation of this function.
|
|
**/
|
|
virtual SampleValue* getSampleValue (const SamplePos pos) const = 0 ;
|
|
|
|
/**
|
|
* replace a sample thus (possibly) altering the value of the bit returned by SampleValue->getBit()
|
|
* \param pos the position of the sample (must be in 0...getNumSamples()-1)
|
|
* \param s the sample value that should replace the current sample value (must be of correct type for this CvrStgObject)
|
|
*
|
|
* The derived class should check the condition(s) given above in its Implementation of this function.
|
|
**/
|
|
virtual void replaceSample (const SamplePos pos, const SampleValue* s) = 0 ;
|
|
} ;
|
|
|
|
#endif //ndef SH_CVRSTGOBJECT_H
|