dlls/quartz/ijgdec.c

   1 /*
   2  * A simple wrapper of JPEG decoder.
   3  *
   4  * Copyright (C) Hidenori TAKESHIMA <hidenori@a2.ctktv.ne.jp>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21
  22 #include "config.h"
  23
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <stdlib.h>
  27
  28 #include "ijgdec.h"
  29
  30 #if defined(HAVE_LIBJPEG) && defined(HAVE_JPEGLIB_H)
  31
  32 #include <jpeglib.h>
  33 #include <jerror.h>
  34 #include <setjmp.h>
  35
  36 typedef struct IJGSrcImpl IJGSrcImpl;
  37 typedef struct IJGErrImpl IJGErrImpl;
  38 struct IJGSrcImpl
  39 {
  40         struct jpeg_source_mgr  pub;    /* must be first */
  41
  42         const char** ppsrcs;
  43         const int* plenofsrcs;
  44         int srccount;
  45         int srcindex;
  46 };
  47
  48 struct IJGErrImpl
  49 {
  50         struct jpeg_error_mgr err;
  51
  52         jmp_buf env;
  53 };
  54
  55
  56 /* for the jpeg decompressor source manager. */
  57 static void IJGDec_init_source(j_decompress_ptr cinfo) {}
  58
  59 static boolean IJGDec_fill_input_buffer(j_decompress_ptr cinfo)
  60 {
  61         IJGSrcImpl* pImpl = (IJGSrcImpl*)cinfo->src;
  62
  63         if ( pImpl->srcindex >= pImpl->srccount )
  64         {
  65                 ERREXIT(cinfo, JERR_INPUT_EMPTY);
  66         }
  67         pImpl->pub.next_input_byte = pImpl->ppsrcs[pImpl->srcindex];
  68         pImpl->pub.bytes_in_buffer = pImpl->plenofsrcs[pImpl->srcindex];
  69         pImpl->srcindex ++;
  70
  71         return TRUE;
  72 }
  73
  74 static void IJGDec_skip_input_data(j_decompress_ptr cinfo,long num_bytes)
  75 {
  76         IJGSrcImpl* pImpl = (IJGSrcImpl*)cinfo->src;
  77
  78         if ( num_bytes <= 0 ) return;
  79
  80         while ( num_bytes > pImpl->pub.bytes_in_buffer )
  81         {
  82                 num_bytes -= pImpl->pub.bytes_in_buffer;
  83                 if ( !IJGDec_fill_input_buffer(cinfo) )
  84                 {
  85                         ERREXIT(cinfo, JERR_INPUT_EMPTY);
  86                 }
  87         }
  88
  89         pImpl->pub.next_input_byte += num_bytes;
  90         pImpl->pub.bytes_in_buffer -= num_bytes;
  91 }
  92
  93 static void IJGDec_term_source(j_decompress_ptr cinfo)
  94 {
  95 }
  96
  97 static void IJGDec_error_exit(j_common_ptr cinfo)
  98 {
  99         IJGErrImpl* pImpl = (IJGErrImpl*)cinfo->err;
 100
 101         longjmp(pImpl->env,1);
 102 }
 103
 104 static void rgb_to_bgr(char* pdata,int width)
 105 {
 106         int x;
 107         char c;
 108
 109         for(x=0;x<width;x++)
 110         {
 111                 c = pdata[0];
 112                 pdata[0] = pdata[2];
 113                 pdata[2] = c;
 114                 pdata += 3;
 115         }
 116 }
 117
 118 int IJGDEC_Decode( char* pdst, int dstpitch, int dstwidth, int dstheight, int dstbpp, const char** ppsrcs, const int* plenofsrcs, int srccount )
 119 {
 120         IJGSrcImpl jsrc;
 121         IJGErrImpl jerr;
 122         struct jpeg_decompress_struct jdec;
 123         int ret = -1;
 124
 125         jsrc.ppsrcs = ppsrcs;
 126         jsrc.plenofsrcs = plenofsrcs;
 127         jsrc.srccount = srccount;
 128         jsrc.srcindex = 0;
 129         jsrc.pub.bytes_in_buffer = 0;
 130         jsrc.pub.next_input_byte = NULL;
 131         jsrc.pub.init_source = IJGDec_init_source;
 132         jsrc.pub.fill_input_buffer = IJGDec_fill_input_buffer;
 133         jsrc.pub.skip_input_data = IJGDec_skip_input_data;
 134         jsrc.pub.resync_to_restart = jpeg_resync_to_restart;
 135         jsrc.pub.term_source = IJGDec_term_source;
 136
 137         jdec.err = jpeg_std_error(&jerr.err);
 138         jerr.err.error_exit = IJGDec_error_exit;
 139
 140         if ( setjmp(jerr.env) != 0 )
 141         {
 142                 jpeg_destroy_decompress(&jdec);
 143                 return -1;
 144         }
 145
 146         jpeg_create_decompress(&jdec);
 147         jdec.src = &jsrc;
 148
 149         ret = jpeg_read_header(&jdec,TRUE);
 150         if ( ret != JPEG_HEADER_OK ) goto err;
 151
 152         jpeg_start_decompress(&jdec);
 153
 154         if ( jdec.output_width != dstwidth ||
 155                  jdec.output_height != dstheight ||
 156                  (jdec.output_components*8) != dstbpp ) goto err;
 157
 158         while (jdec.output_scanline < jdec.output_height)
 159         {
 160                 jpeg_read_scanlines(&jdec,(JSAMPLE**)&pdst,1);
 161                 rgb_to_bgr(pdst,dstwidth);
 162                 pdst += dstpitch;
 163         }
 164
 165         jpeg_finish_decompress(&jdec);
 166         ret = 0;
 167 err:
 168         jpeg_destroy_decompress(&jdec);
 169
 170         return ret;
 171 }
 172
 173 #else
 174
 175 int IJGDEC_Decode( char* pdst, int dstpitch, int dstwidth, int dstheight, int dstbpp, const char** ppsrcs, const int* plenofsrcs, int srccount )
 176 {
 177         return -1;
 178 }
 179
 180 #endif
 181
 182