JPG Information

/* 

DESCRIPTION:  Extracts any information after the actual end of a JPEG file.

*/



#include 

#include 

#include 

using namespace std;



unsigned long int szFile;

char * buffer;



int main(int argc, char* argv[])

{

    char *buffer;

    int dataBegin;

    char SOI[] = { 0xFF, 0xD8 }; //Start of Image

    char COMM[] = { 0xFF, 0xFE }; //Comments Follow

    char EOI[] = { 0xFF, 0xD9 }; //End of Image

    ifstream fin;

    ofstream fout;

    if(argc != 3 ) {

        cout << "Usage: " << argv[0] << " file.jpg outputfile.ext" << endl;

        exit(EXIT_SUCCESS);

    }



    fin.open(argv[1], ios::binary | ios::in | ios::ate);

    if(!fin.is_open()) {

        cerr << "Error while opening input file!" << endl;

        exit(EXIT_FAILURE);

    }

    szFile = (unsigned long int) fin.tellg();

    if(szFile < 4) {

        cerr << "Not a valid jpg image file!" << endl;

        exit(EXIT_SUCCESS);

    }

    

    buffer = new char[szFile];

    fin.seekg (0, ios::beg);

    fin.read (buffer, szFile);

    fin.close();

    

    if(buffer[0] != (char) 0xFF || buffer[1] != (char) 0xD8) {

        cerr << "Not a valid jpeg image file!" << endl;

        exit(EXIT_SUCCESS);

    }

    

    bool comments = false;

    for(unsigned long int i = 2; i < szFile-1; i++) {

        if(buffer[i] == COMM[0] && buffer[i+1] == COMM[1]) {

            cout << "Jpeg Comments: "; comments = true;

        }



        if(buffer[i] == EOI[0] && buffer[i+1] == EOI[1]) {

            if(comments){

                //end comments section;

                comments=false;

                cout << endl;

            }

            cout << "Jpeg Image Size: " << i+1 << " bytes" << endl;

            dataBegin = i + 2;

            break;

        }

        if(comments) cout << (char)buffer[i];

    }



    fout.open(argv[2], ios::out | ios::binary);

    if(!fout.is_open()) {

        cerr << "Error while opening output file!" << endl;

        exit(EXIT_FAILURE);

    }

    for(unsigned long int i = dataBegin; i < szFile; i++) {

        fout.put(buffer[i]);

    }

    fout.close();

    cout << "Done Writing " << szFile - dataBegin << " bytes to " << argv[2] << endl;



    delete[] buffer;

    exit(EXIT_SUCCESS);

}