102 lines
2.8 KiB
C
102 lines
2.8 KiB
C
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/****************************************************************************
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jpeg.c - read and write jpeg images using libjpeg routines
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Copyright (C) 2002 Hari Nair <hari@alumni.caltech.edu>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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****************************************************************************/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <jpeglib.h>
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#include "const.h"
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int read_jpeg(const char *filename, int *width, int *height, unsigned char **rgb)
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{
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int ret = 0;
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struct jpeg_decompress_struct cinfo;
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struct jpeg_error_mgr jerr;
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unsigned char *ptr = NULL;
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unsigned int i, ipos;
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FILE *infile = fopen(filename, "rb");
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if (infile == NULL) {
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fprintf(stderr, "Can not fopen file: %s\n",filename);
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return ret;
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}
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cinfo.err = jpeg_std_error(&jerr);
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jpeg_create_decompress(&cinfo);
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jpeg_stdio_src(&cinfo, infile);
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jpeg_read_header(&cinfo, TRUE);
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jpeg_start_decompress(&cinfo);
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/* Prevent against integer overflow */
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if(cinfo.output_width >= MAX_DIMENSION || cinfo.output_height >= MAX_DIMENSION) {
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fprintf(stderr, "Unreasonable dimension found in file: %s\n",filename);
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goto close_file;
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}
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*width = cinfo.output_width;
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*height = cinfo.output_height;
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rgb[0] = malloc(3 * cinfo.output_width * cinfo.output_height);
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if (rgb[0] == NULL) {
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fprintf(stderr, "Can't allocate memory for JPEG file.\n");
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goto close_file;
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}
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if (cinfo.output_components == 3) {
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ptr = rgb[0];
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while (cinfo.output_scanline < cinfo.output_height) {
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jpeg_read_scanlines(&cinfo, &ptr, 1);
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ptr += 3 * cinfo.output_width;
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}
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} else if (cinfo.output_components == 1) {
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ptr = malloc(cinfo.output_width);
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if (ptr == NULL) {
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fprintf(stderr, "Can't allocate memory for JPEG file.\n");
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goto rgb_free;
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}
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ipos = 0;
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while (cinfo.output_scanline < cinfo.output_height) {
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jpeg_read_scanlines(&cinfo, &ptr, 1);
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for (i = 0; i < cinfo.output_width; i++) {
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memset(rgb[0] + ipos, ptr[i], 3);
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ipos += 3;
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}
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}
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free(ptr);
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}
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jpeg_finish_decompress(&cinfo);
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ret = 1;
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goto close_file;
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rgb_free:
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free(rgb[0]);
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close_file:
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jpeg_destroy_decompress(&cinfo);
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fclose(infile);
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return(ret);
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}
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