grayscreenshotlib - main.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>


int main(int argc, char** argv)
{
    int c, i, byte, filesize;
    char bit, pix;
    unsigned char *light_buffer, *dark_buffer;
    char command[100];
    FILE *file, *output;

    if(file = fopen("MOVIE.gsl", "r")) {
        fseek(file, 0, SEEK_END);
        filesize = ftell(file);
        fseek(file, 0, SEEK_SET);
        if(filesize % 2048 == 0) {
            mkdir("tmp", 01777);
            light_buffer = malloc(1024);
            dark_buffer = malloc(1024);
            for(i=0 ; i<filesize/2048 ; i++) {
                output = fopen("tmp/bmp24", "w+");
                fread(light_buffer, 1, 1024, file);
                fread(dark_buffer, 1, 1024, file);
                for(byte=0 ; byte<1024 ; byte++) {
                    for(bit=0 ; bit<8 ; bit++) {
                        pix = (light_buffer[byte] & (1<<(7-bit)) ? 1 : 0);
                        pix |= (dark_buffer[byte] & (1<<(7-bit)) ? 2 : 0);
                        switch(pix) {
                            case 0:
                                fprintf(output, "%c%c%c", 255, 255, 255);
                                break;
                            case 1:
                                fprintf(output, "%c%c%c", 192, 192, 192);
                                break;
                            case 2:
                                fprintf(output, "%c%c%c", 128, 128, 128);
                                break;
                            case 3:
                                fprintf(output, "%c%c%c", 0, 0, 0);
                                break;
                        }
                    }
                }
                fclose(output);
                sprintf(command, "rgb2gif -1 -s 128 64 tmp/bmp24 > tmp/%06i.gif", i);
                system(command);
                remove("tmp/bmp24");
            }
                free(light_buffer);
            free(dark_buffer);
            system("gifasm -A 7 $(find tmp/*.gif) > result.gif");
        } else fprintf(stderr, "Invalid file size.\n");
        fclose(file);
    } else fprintf(stderr, "Can't find \"MOVIE.gsl\".\n");
    return EXIT_SUCCESS;
}