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   1 /*
   2 libimago - a multi-format image file input/output library.
   3 Copyright (C) 2010 John Tsiombikas <nuclear@member.fsf.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published
   7 by the Free Software Foundation, either version 3 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License
  16 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 /* -- JPEG module -- */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #ifdef WIN32
  26 #include <windows.h>
  27 #define HAVE_BOOLEAN
  28 #endif
  29
  30 #include <jpeglib.h>
  31 #include "imago2.h"
  32 #include "ftmodule.h"
  33
  34 #define INPUT_BUF_SIZE  512
  35 #define OUTPUT_BUF_SIZE 512
  36
  37 /* data source manager: adapted from jdatasrc.c */
  38 struct src_mgr {
  39         struct jpeg_source_mgr pub;
  40
  41         struct img_io *io;
  42         unsigned char buffer[INPUT_BUF_SIZE];
  43         int start_of_file;
  44 };
  45
  46 /* data destination manager: adapted from jdatadst.c */
  47 struct dst_mgr {
  48         struct jpeg_destination_mgr pub;
  49
  50         struct img_io *io;
  51         unsigned char buffer[OUTPUT_BUF_SIZE];
  52 };
  53
  54 static int check(struct img_io *io);
  55 static int read(struct img_pixmap *img, struct img_io *io);
  56 static int write(struct img_pixmap *img, struct img_io *io);
  57
  58 /* read source functions */
  59 static void init_source(j_decompress_ptr jd);
  60 static boolean fill_input_buffer(j_decompress_ptr jd);
  61 static void skip_input_data(j_decompress_ptr jd, long num_bytes);
  62 static void term_source(j_decompress_ptr jd);
  63
  64 /* write destination functions */
  65 static void init_destination(j_compress_ptr jc);
  66 static boolean empty_output_buffer(j_compress_ptr jc);
  67 static void term_destination(j_compress_ptr jc);
  68
  69 int img_register_jpeg(void)
  70 {
  71         static struct ftype_module mod = {".jpg", check, read, write};
  72         return img_register_module(&mod);
  73 }
  74
  75
  76 static int check(struct img_io *io)
  77 {
  78         unsigned char sig[10];
  79
  80         long pos = io->seek(0, SEEK_CUR, io->uptr);
  81
  82         if(io->read(sig, 10, io->uptr) < 10) {
  83                 io->seek(pos, SEEK_SET, io->uptr);
  84                 return -1;
  85         }
  86
  87         if(memcmp(sig, "\xff\xd8\xff\xe0", 4) != 0 && memcmp(sig, "\xff\xd8\xff\xe1", 4) != 0
  88                         && memcmp(sig, "\xff\xd8\xff\xdb", 4) != 0 && memcmp(sig + 6, "JFIF", 4) != 0) {
  89                 io->seek(pos, SEEK_SET, io->uptr);
  90                 return -1;
  91         }
  92         io->seek(pos, SEEK_SET, io->uptr);
  93         return 0;
  94 }
  95
  96 static int read(struct img_pixmap *img, struct img_io *io)
  97 {
  98         int i, nlines = 0;
  99         struct jpeg_decompress_struct cinfo;
 100         struct jpeg_error_mgr jerr;
 101         struct src_mgr src;
 102         unsigned char **scanlines;
 103
 104         io->seek(0, SEEK_CUR, io->uptr);
 105
 106         cinfo.err = jpeg_std_error(&jerr);      /* XXX change... */
 107         jpeg_create_decompress(&cinfo);
 108
 109         src.pub.init_source = init_source;
 110         src.pub.fill_input_buffer = fill_input_buffer;
 111         src.pub.skip_input_data = skip_input_data;
 112         src.pub.resync_to_restart = jpeg_resync_to_restart;
 113         src.pub.term_source = term_source;
 114         src.pub.next_input_byte = 0;
 115         src.pub.bytes_in_buffer = 0;
 116         src.io = io;
 117         cinfo.src = (struct jpeg_source_mgr*)&src;
 118
 119         jpeg_read_header(&cinfo, 1);
 120         cinfo.out_color_space = JCS_RGB;
 121
 122         if(img_set_pixels(img, cinfo.image_width, cinfo.image_height, IMG_FMT_RGB24, 0) == -1) {
 123                 jpeg_destroy_decompress(&cinfo);
 124                 return -1;
 125         }
 126
 127         if(!(scanlines = malloc(img->height * sizeof *scanlines))) {
 128                 jpeg_destroy_decompress(&cinfo);
 129                 return -1;
 130         }
 131         scanlines[0] = img->pixels;
 132         for(i=1; i<img->height; i++) {
 133                 scanlines[i] = scanlines[i - 1] + img->width * img->pixelsz;
 134         }
 135
 136         jpeg_start_decompress(&cinfo);
 137         while(nlines < img->height) {
 138                 int res = jpeg_read_scanlines(&cinfo, scanlines + nlines, img->height - nlines);
 139                 nlines += res;
 140         }
 141         jpeg_finish_decompress(&cinfo);
 142         jpeg_destroy_decompress(&cinfo);
 143
 144         free(scanlines);
 145         return 0;
 146 }
 147
 148 static int write(struct img_pixmap *img, struct img_io *io)
 149 {
 150         int i, nlines = 0;
 151         struct jpeg_compress_struct cinfo;
 152         struct jpeg_error_mgr jerr;
 153         struct dst_mgr dest;
 154         struct img_pixmap tmpimg;
 155         unsigned char **scanlines;
 156
 157         img_init(&tmpimg);
 158
 159         if(img->fmt != IMG_FMT_RGB24) {
 160                 if(img_copy(&tmpimg, img) == -1) {
 161                         return -1;
 162                 }
 163                 if(img_convert(&tmpimg, IMG_FMT_RGB24) == -1) {
 164                         img_destroy(&tmpimg);
 165                         return -1;
 166                 }
 167                 img = &tmpimg;
 168         }
 169
 170         if(!(scanlines = malloc(img->height * sizeof *scanlines))) {
 171                 img_destroy(&tmpimg);
 172                 return -1;
 173         }
 174         scanlines[0] = img->pixels;
 175         for(i=1; i<img->height; i++) {
 176                 scanlines[i] = scanlines[i - 1] + img->width * img->pixelsz;
 177         }
 178
 179         cinfo.err = jpeg_std_error(&jerr);      /* XXX */
 180         jpeg_create_compress(&cinfo);
 181
 182         dest.pub.init_destination = init_destination;
 183         dest.pub.empty_output_buffer = empty_output_buffer;
 184         dest.pub.term_destination = term_destination;
 185         dest.io = io;
 186         cinfo.dest = (struct jpeg_destination_mgr*)&dest;
 187
 188         cinfo.image_width = img->width;
 189         cinfo.image_height = img->height;
 190         cinfo.input_components = 3;
 191         cinfo.in_color_space = JCS_RGB;
 192
 193         jpeg_set_defaults(&cinfo);
 194
 195         jpeg_start_compress(&cinfo, 1);
 196         while(nlines < img->height) {
 197                 int res = jpeg_write_scanlines(&cinfo, scanlines + nlines, img->height - nlines);
 198                 nlines += res;
 199         }
 200         jpeg_finish_compress(&cinfo);
 201         jpeg_destroy_compress(&cinfo);
 202
 203         free(scanlines);
 204         img_destroy(&tmpimg);
 205         return 0;
 206 }
 207
 208 /* -- read source functions --
 209  * the following functions are adapted from jdatasrc.c in jpeglib
 210  */
 211 static void init_source(j_decompress_ptr jd)
 212 {
 213         struct src_mgr *src = (struct src_mgr*)jd->src;
 214         src->start_of_file = 1;
 215 }
 216
 217 static boolean fill_input_buffer(j_decompress_ptr jd)
 218 {
 219         struct src_mgr *src = (struct src_mgr*)jd->src;
 220         size_t nbytes;
 221
 222         nbytes = src->io->read(src->buffer, INPUT_BUF_SIZE, src->io->uptr);
 223
 224         if(nbytes <= 0) {
 225                 if(src->start_of_file) {
 226                         return 0;
 227                 }
 228                 /* insert a fake EOI marker */
 229                 src->buffer[0] = 0xff;
 230                 src->buffer[1] = JPEG_EOI;
 231                 nbytes = 2;
 232         }
 233
 234         src->pub.next_input_byte = src->buffer;
 235         src->pub.bytes_in_buffer = nbytes;
 236         src->start_of_file = 0;
 237         return 1;
 238 }
 239
 240 static void skip_input_data(j_decompress_ptr jd, long num_bytes)
 241 {
 242         struct src_mgr *src = (struct src_mgr*)jd->src;
 243
 244         if(num_bytes > 0) {
 245                 while(num_bytes > (long)src->pub.bytes_in_buffer) {
 246                         num_bytes -= (long)src->pub.bytes_in_buffer;
 247                         fill_input_buffer(jd);
 248                 }
 249                 src->pub.next_input_byte += (size_t)num_bytes;
 250                 src->pub.bytes_in_buffer -= (size_t)num_bytes;
 251         }
 252 }
 253
 254 static void term_source(j_decompress_ptr jd)
 255 {
 256         /* nothing to see here, move along */
 257 }
 258
 259
 260 /* -- write destination functions --
 261  * the following functions are adapted from jdatadst.c in jpeglib
 262  */
 263 static void init_destination(j_compress_ptr jc)
 264 {
 265         struct dst_mgr *dest = (struct dst_mgr*)jc->dest;
 266
 267         dest->pub.next_output_byte = dest->buffer;
 268         dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
 269 }
 270
 271 static boolean empty_output_buffer(j_compress_ptr jc)
 272 {
 273         struct dst_mgr *dest = (struct dst_mgr*)jc->dest;
 274
 275         if(dest->io->write(dest->buffer, OUTPUT_BUF_SIZE, dest->io->uptr) != OUTPUT_BUF_SIZE) {
 276                 return 0;
 277         }
 278
 279         dest->pub.next_output_byte = dest->buffer;
 280         dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
 281         return 1;
 282 }
 283
 284 static void term_destination(j_compress_ptr jc)
 285 {
 286         struct dst_mgr *dest = (struct dst_mgr*)jc->dest;
 287         size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
 288
 289         /* write any remaining data in the buffer */
 290         if(datacount > 0) {
 291                 dest->io->write(dest->buffer, datacount, dest->io->uptr);
 292         }
 293         /* XXX flush? ... */
 294 }