Sweden-Number/dlls/quartz/ijgdec.c

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2002-04-19 02:05:05 +02:00
/*
* A simple wrapper of JPEG decoder.
*
* Copyright (C) Hidenori TAKESHIMA <hidenori@a2.ctktv.ne.jp>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "config.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "ijgdec.h"
#if defined(HAVE_LIBJPEG) && defined(HAVE_JPEGLIB_H)
#include <jpeglib.h>
#include <jerror.h>
#include <setjmp.h>
typedef struct IJGSrcImpl IJGSrcImpl;
typedef struct IJGErrImpl IJGErrImpl;
struct IJGSrcImpl
{
struct jpeg_source_mgr pub; /* must be first */
const char** ppsrcs;
const int* plenofsrcs;
int srccount;
int srcindex;
};
struct IJGErrImpl
{
struct jpeg_error_mgr err;
jmp_buf env;
};
/* for the jpeg decompressor source manager. */
static void IJGDec_init_source(j_decompress_ptr cinfo) {}
static boolean IJGDec_fill_input_buffer(j_decompress_ptr cinfo)
{
IJGSrcImpl* pImpl = (IJGSrcImpl*)cinfo->src;
if ( pImpl->srcindex >= pImpl->srccount )
{
ERREXIT(cinfo, JERR_INPUT_EMPTY);
}
pImpl->pub.next_input_byte = pImpl->ppsrcs[pImpl->srcindex];
pImpl->pub.bytes_in_buffer = pImpl->plenofsrcs[pImpl->srcindex];
pImpl->srcindex ++;
return TRUE;
}
static void IJGDec_skip_input_data(j_decompress_ptr cinfo,long num_bytes)
{
IJGSrcImpl* pImpl = (IJGSrcImpl*)cinfo->src;
if ( num_bytes <= 0 ) return;
while ( num_bytes > pImpl->pub.bytes_in_buffer )
{
num_bytes -= pImpl->pub.bytes_in_buffer;
if ( !IJGDec_fill_input_buffer(cinfo) )
{
ERREXIT(cinfo, JERR_INPUT_EMPTY);
}
}
pImpl->pub.next_input_byte += num_bytes;
pImpl->pub.bytes_in_buffer -= num_bytes;
}
static void IJGDec_term_source(j_decompress_ptr cinfo)
{
}
static void IJGDec_error_exit(j_common_ptr cinfo)
{
IJGErrImpl* pImpl = (IJGErrImpl*)cinfo->err;
longjmp(pImpl->env,1);
}
static void rgb_to_bgr(char* pdata,int width)
{
int x;
char c;
for(x=0;x<width;x++)
{
c = pdata[0];
pdata[0] = pdata[2];
pdata[2] = c;
pdata += 3;
}
}
int IJGDEC_Decode( char* pdst, int dstpitch, int dstwidth, int dstheight, int dstbpp, const char** ppsrcs, const int* plenofsrcs, int srccount )
{
IJGSrcImpl jsrc;
IJGErrImpl jerr;
struct jpeg_decompress_struct jdec;
int ret = -1;
jsrc.ppsrcs = ppsrcs;
jsrc.plenofsrcs = plenofsrcs;
jsrc.srccount = srccount;
jsrc.srcindex = 0;
jsrc.pub.bytes_in_buffer = 0;
jsrc.pub.next_input_byte = NULL;
jsrc.pub.init_source = IJGDec_init_source;
jsrc.pub.fill_input_buffer = IJGDec_fill_input_buffer;
jsrc.pub.skip_input_data = IJGDec_skip_input_data;
jsrc.pub.resync_to_restart = jpeg_resync_to_restart;
jsrc.pub.term_source = IJGDec_term_source;
jdec.err = jpeg_std_error(&jerr.err);
jerr.err.error_exit = IJGDec_error_exit;
if ( setjmp(jerr.env) != 0 )
{
jpeg_destroy_decompress(&jdec);
return -1;
}
jpeg_create_decompress(&jdec);
jdec.src = &jsrc;
ret = jpeg_read_header(&jdec,TRUE);
if ( ret != JPEG_HEADER_OK ) goto err;
jpeg_start_decompress(&jdec);
if ( jdec.output_width != dstwidth ||
jdec.output_height != dstheight ||
(jdec.output_components*8) != dstbpp ) goto err;
while (jdec.output_scanline < jdec.output_height)
{
jpeg_read_scanlines(&jdec,(JSAMPLE**)&pdst,1);
rgb_to_bgr(pdst,dstwidth);
pdst += dstpitch;
}
jpeg_finish_decompress(&jdec);
ret = 0;
err:
jpeg_destroy_decompress(&jdec);
return ret;
}
#else
int IJGDEC_Decode( char* pdst, int dstpitch, int dstwidth, int dstheight, int dstbpp, const char** ppsrcs, const int* plenofsrcs, int srccount )
{
return -1;
}
#endif