pngtest.c

/* pngtest.c - a simple test program to test libpng 

   libpng 1.0 beta 1 - version 0.71
   For conditions of distribution and use, see copyright notice in png.h
   Copyright (c) 1995 Guy Eric Schalnat, Group 42, Inc.
   June 26, 1995
   */

#include <stdio.h>
#include <stdlib.h>
#include "png.h"

#ifdef __TURBOC__
#include <mem.h>
#endif

/* defined so I can write to a file on gui/windowing platforms */
#define STDERR stderr

/* input and output filenames */
char inname[] = "pngtest.png";
char outname[] = "pngout.png";

png_struct read_ptr;
png_struct write_ptr;
png_info info_ptr;
png_info end_info;

char inbuf[256], outbuf[256];

int main()
{
	FILE *fpin, *fpout;
	png_byte *row_buf;
	png_uint_32 rowbytes;
   png_uint_32 y;
	int channels, num_pass, pass;

	row_buf = (png_byte *)0;

	fpin = fopen(inname, "rb");
	if (!fpin)
	{
		fprintf(STDERR, "Could not find input file %s\n", inname);
		return -1;
	}

	fpout = fopen(outname, "wb");
	if (!fpin)
	{
		fprintf(STDERR, "could not open output file %s\n", outname);
		fclose(fpin);
		return -1;
	}

	if (setjmp(read_ptr.jmpbuf))
	{
		fprintf(STDERR, "libpng read error\n");
		fclose(fpin);
		fclose(fpout);
		return -1;
	}

	if (setjmp(write_ptr.jmpbuf))
	{
		fprintf(STDERR, "libpng write error\n");
		fclose(fpin);
		fclose(fpout);
		return -1;
	}

	png_read_init(&read_ptr);
	png_write_init(&write_ptr);
	png_info_init(&info_ptr);
	png_info_init(&end_info);

	png_init_io(&read_ptr, fpin);
	png_init_io(&write_ptr, fpout);

	png_read_info(&read_ptr, &info_ptr);
	png_write_info(&write_ptr, &info_ptr);

	if ((info_ptr.color_type & 3) == 2)
		channels = 3;
	else
		channels = 1;
	if (info_ptr.color_type & 4)
		channels++;

	rowbytes = ((info_ptr.width * info_ptr.bit_depth * channels + 7) >> 3);
	row_buf = (png_byte *)malloc((size_t)rowbytes);
	if (!row_buf)
	{
		fprintf(STDERR, "no memory to allocate row buffer\n");
		png_read_destroy(&read_ptr, &info_ptr, (png_info *)0);
		png_write_destroy(&write_ptr);
		fclose(fpin);
		fclose(fpout);
		return -1;
	}

	if (info_ptr.interlace_type)
	{
		num_pass = png_set_interlace_handling(&read_ptr);
		num_pass = png_set_interlace_handling(&write_ptr);
	}
	else
	{
		num_pass = 1;
	}

	for (pass = 0; pass < num_pass; pass++)
	{
		for (y = 0; y < info_ptr.height; y++)
		{
			png_read_rows(&read_ptr, &row_buf, (png_byte **)0, 1);
			png_write_rows(&write_ptr, &row_buf, 1);
		}
	}

	png_read_end(&read_ptr, &end_info);
	png_write_end(&write_ptr, &end_info);

	png_read_destroy(&read_ptr, &info_ptr, &end_info);
	png_write_destroy(&write_ptr);

	fclose(fpin);
	fclose(fpout);

	free(row_buf);

	fpin = fopen(inname, "rb");

	if (!fpin)
	{
		fprintf(STDERR, "could not find file %s\n", inname);
		return -1;
	}

	fpout = fopen(outname, "rb");
	if (!fpout)
	{
		fprintf(STDERR, "could not find file %s\n", outname);
		fclose(fpin);
		return -1;
	}

	while (1)
	{
		int num_in, num_out;

		num_in = fread(inbuf, 1, 256, fpin);
		num_out = fread(outbuf, 1, 256, fpout);

		if (num_in != num_out)
		{
			fprintf(STDERR, "files are of a different size\n");
			fclose(fpin);
			fclose(fpout);
			return -1;
		}

		if (!num_in)
			break;

		if (memcmp(inbuf, outbuf, num_in))
		{
			fprintf(STDERR, "files are different\n");
			fclose(fpin);
			fclose(fpout);
			return -1;
		}
	}

	fclose(fpin);
	fclose(fpout);
   fprintf(STDERR, "libpng passes test\n");

   return 0;
}