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/*
* Copyright 1996, Torsten Martinsen
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* $Id: writeJPEG.c,v 1.4 1996/05/07 11:22:06 torsten Exp $ */
#include <stdio.h>
#include <stdlib.h>
#include <setjmp.h>
#include <jpeglib.h>
#include "image.h"
#include "rwTable.h"
extern void *xmalloc(size_t n);
static void
trace_message(j_common_ptr cinfo)
{
char buf[JMSG_LENGTH_MAX];
cinfo->err->format_message(cinfo, buf);
RWSetMsg(buf);
}
struct error_mgr {
struct jpeg_error_mgr pub; /* "public" fields */
jmp_buf setjmp_buffer; /* for return to caller */
};
static struct error_mgr jerr;
typedef struct error_mgr *error_ptr;
/*
* Here's the routine that will replace the standard error_exit method:
*/
static void
error_exit(j_common_ptr cinfo)
{
/* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
error_ptr err = (error_ptr) cinfo->err;
trace_message(cinfo);
/* Return control to the setjmp point */
longjmp(err->setjmp_buffer, 1);
}
int
WriteJPEG(char *file, Image * outImage)
{
struct jpeg_compress_struct cinfo;
FILE *output_file;
int w, i, row_stride;
JSAMPROW scanline[1];
unsigned char *p, *d, *theline;
if ((output_file = fopen(file, "w")) == NULL)
return 1;
w = outImage->width;
cinfo.err = jpeg_std_error(&jerr.pub);
jerr.pub.error_exit = error_exit;
if (setjmp(jerr.setjmp_buffer)) {
/* If we get here, the JPEG code has signaled an error.
* We need to clean up the JPEG object, close the output file,
* and return.
*/
jpeg_destroy_compress(&cinfo);
fclose(output_file);
return 1;
}
jpeg_create_compress(&cinfo);
jpeg_stdio_dest(&cinfo, output_file);
cinfo.image_height = outImage->height;
cinfo.image_width = w;
if (outImage->isGrey) {
cinfo.in_color_space = JCS_GRAYSCALE;
cinfo.input_components = 1;
} else {
cinfo.in_color_space = JCS_RGB;
cinfo.input_components = 3;
theline = xmalloc(w * 3);
}
jpeg_set_defaults(&cinfo);
jpeg_start_compress(&cinfo, TRUE);
row_stride = w * cinfo.input_components;
while (cinfo.next_scanline < cinfo.image_height) {
/*
* If we have a greyscale or TrueColor image, just feed
* the raw data to the JPEG routine. Otherwise, we must
* build an array of RGB triples in 'theline'.
*/
if (outImage->isGrey || (outImage->cmapSize == 0))
scanline[0] = (JSAMPROW) outImage->data +
cinfo.next_scanline * row_stride;
else {
d = theline;
for (i = 0; i < w; ++i) {
p = ImagePixel(outImage, i, cinfo.next_scanline);
*d++ = *p++;
*d++ = *p++;
*d++ = *p;
}
scanline[0] = theline;
}
jpeg_write_scanlines(&cinfo, scanline, (JDIMENSION) 1);
}
jpeg_finish_compress(&cinfo);
jpeg_destroy_compress(&cinfo);
fclose(output_file);
if (!outImage->isGrey)
free(theline);
if (jerr.pub.num_warnings > 0) { /* XXX */
RWSetMsg("JPEG warning, image may be corrupted");
longjmp(jerr.setjmp_buffer, 1);
}
return 0;
}
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