mxjpeg.cpp

/*
        MX library.

        http://lostsidedead.com/svn


        libmx written by jared bruni, it is wrappers around SDL
and other api's to provide a set of classes and functions
to produce multi media applications, using object oriented
techniques.

        (C) 2008 LostSideDead
*/


#include "mxjpeg.h"
#include<iostream>


namespace mx
{

        bool mxJpeg::jpgOpen(FILE *fptr) {


                jpeg_decompress_struct deInfo;
                jpeg_error_mgr deErr;

                deInfo.err = jpeg_std_error(&deErr);
                jpeg_create_decompress(&deInfo);
                jpeg_stdio_src(&deInfo, fptr);
                jpeg_read_header(&deInfo, TRUE);
                jpeg_start_decompress(&deInfo);

                int width = deInfo.output_width, height = deInfo.output_height, depth = deInfo.num_components;
                int output_lines = deInfo.output_height;

                if(data != 0) delete [] data;
                data = 0;

                data = new unsigned char [ ( width * height ) * depth ];
                JSAMPROW row_ptr[1];

                row_ptr[0] = (unsigned char*) malloc(deInfo.output_width*deInfo.num_components);

                unsigned int i = 0;
                unsigned long location = 0;

                while (deInfo.output_scanline < deInfo.image_height)
                {
                    jpeg_read_scanlines(&deInfo, row_ptr, 1);
                        for(i = 0; i <deInfo.image_width*deInfo.num_components; i++)
                                data[location++] = row_ptr[0][i];
                 }

                jpeg_finish_decompress(&deInfo);
                jpeg_destroy_decompress(&deInfo);
                w = width, h = height, bytes = depth;
                fclose(fptr);
                free(row_ptr[0]);

                return true;
        }

        bool mxJpeg::jpgOpen(string fileName) {


                FILE *fptr = fopen(fileName.c_str(), "rb");

                if(fptr == 0) return false;

                return jpgOpen(fptr);

        }


        SDL_Surface *mxJpeg::LoadJPG() {

                SDL_Surface *surf = CreateBuffer(w,h);


                if(SDL_MUSTLOCK(surf)) SDL_LockSurface(surf);


                unsigned int *pixels = (unsigned int*) surf->pixels;
                unsigned int *buf = (unsigned int *) data;
                unsigned int pos = 0;
                unsigned char *dat = (unsigned char*) data;

                while ( pos < (w*h) ) {
                        unsigned char *v = dat;
                        pixels[pos++] = SDL_MapRGB(surf->format, v[0], v[1], v[2]);
                        dat += bytes;
                }

                if(SDL_MUSTLOCK(surf)) SDL_UnlockSurface(surf);

                return surf;
        }

        void mxJpeg::jpgClose() {

                if(data) delete [] data;
                data = 0;
        }


}

---