/*
 * Copyright (c) 1998 by Tsuyoshi Iguchi (zinnia@risky-safety.org)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	$Id$
 */
/*
 * downsample.c -- downsampling
 */
#include <math.h>

#include <sys/stat.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <stdio.h>
#define DOWNSAMPLE 4

typedef unsigned long dword;
typedef unsigned short word;
typedef unsigned char byte;

int filesize(char* filename)
{
  struct stat filestat;
  stat(filename, &filestat);
  return filestat.st_size;
}

int main(int argc, char** argv)
{
  FILE* fpin; char** p;
  char* filename;
  unsigned char* rusterx;
  char* datap;
  char* data;
  int i, r, j;
  int srcx, srcy;

  fpin = NULL;
  for(p = argv + 1; *p;){
    if(fpin == NULL){
      fpin = fopen(*p, "r");
      if(fpin == NULL){
	fprintf(stderr, "%s: open error.\n", *p);
	return -1;
      }
      filename = strdup(*p);
    }
    p++;
  }

  if(fpin == NULL){
    fprintf(stderr, "No input files.\n");
    return 1;
  }

  srcx = srcy = sqrt(filesize(filename));
  data = (char*)calloc(srcx * srcy, 1);
  if(data == NULL){
    fprintf(stderr, "Memory allocation error.\n");
    return -1;
  }
  rusterx = (unsigned char*)calloc(srcx, 1);
  if(rusterx == NULL){
    fprintf(stderr, "Memory allocation error.\n");
    return -1;
  }
  datap = data;
  while(!feof(fpin)){
    for(j = 0; j < DOWNSAMPLE; j++){
      fread(rusterx, 1, srcx, fpin);
    }
    for(j = 0; j < srcx; j+=DOWNSAMPLE){
      fprintf(stdout, "%c", rusterx[j]);
    }
  }
  return 0;
}