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   1 /*
   2 libimago - a multi-format image file input/output library.
   3 Copyright (C) 2010-2017 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 #ifndef NO_JPEG
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #ifdef WIN32
  27 #include <windows.h>
  28 #define HAVE_BOOLEAN
  29 #endif
  30
  31 #include <jpeglib.h>
  32 #include "imago2.h"
  33 #include "ftype_module.h"
  34
  35 #define INPUT_BUF_SIZE  512
  36 #define OUTPUT_BUF_SIZE 512
  37
  38 /* data source manager: adapted from jdatasrc.c */
  39 struct src_mgr {
  40         struct jpeg_source_mgr pub;
  41
  42         struct img_io *io;
  43         unsigned char buffer[INPUT_BUF_SIZE];
  44         int start_of_file;
  45 };
  46
  47 /* data destination manager: adapted from jdatadst.c */
  48 struct dst_mgr {
  49         struct jpeg_destination_mgr pub;
  50
  51         struct img_io *io;
  52         unsigned char buffer[OUTPUT_BUF_SIZE];
  53 };
  54
  55 static int check(struct img_io *io);
  56 static int read(struct img_pixmap *img, struct img_io *io);
  57 static int write(struct img_pixmap *img, struct img_io *io);
  58
  59 /* read source functions */
  60 static void init_source(j_decompress_ptr jd);
  61 static boolean fill_input_buffer(j_decompress_ptr jd);
  62 static void skip_input_data(j_decompress_ptr jd, long num_bytes);
  63 static void term_source(j_decompress_ptr jd);
  64
  65 /* write destination functions */
  66 static void init_destination(j_compress_ptr jc);
  67 static boolean empty_output_buffer(j_compress_ptr jc);
  68 static void term_destination(j_compress_ptr jc);
  69
  70 int img_register_jpeg(void)
  71 {
  72         static struct ftype_module mod = {".jpg:.jpeg", check, read, write};
  73         return img_register_module(&mod);
  74 }
  75
  76
  77 static int check(struct img_io *io)
  78 {
  79         unsigned char sig[10];
  80
  81         long pos = io->seek(0, SEEK_CUR, io->uptr);
  82
  83         if(io->read(sig, 10, io->uptr) < 10) {
  84                 io->seek(pos, SEEK_SET, io->uptr);
  85                 return -1;
  86         }
  87
  88         if(memcmp(sig, "\xff\xd8\xff\xe0", 4) != 0 && memcmp(sig, "\xff\xd8\xff\xe1", 4) != 0
  89                         && memcmp(sig, "\xff\xd8\xff\xdb", 4) != 0 && memcmp(sig + 6, "JFIF", 4) != 0) {
  90                 io->seek(pos, SEEK_SET, io->uptr);
  91                 return -1;
  92         }
  93         io->seek(pos, SEEK_SET, io->uptr);
  94         return 0;
  95 }
  96
  97 static int read(struct img_pixmap *img, struct img_io *io)
  98 {
  99         int i, nlines = 0;
 100         struct jpeg_decompress_struct cinfo;
 101         struct jpeg_error_mgr jerr;
 102         struct src_mgr src;
 103         unsigned char **scanlines;
 104
 105         io->seek(0, SEEK_CUR, io->uptr);
 106
 107         cinfo.err = jpeg_std_error(&jerr);      /* XXX change... */
 108         jpeg_create_decompress(&cinfo);
 109
 110         src.pub.init_source = init_source;
 111         src.pub.fill_input_buffer = fill_input_buffer;
 112         src.pub.skip_input_data = skip_input_data;
 113         src.pub.resync_to_restart = jpeg_resync_to_restart;
 114         src.pub.term_source = term_source;
 115         src.pub.next_input_byte = 0;
 116         src.pub.bytes_in_buffer = 0;
 117         src.io = io;
 118         cinfo.src = (struct jpeg_source_mgr*)&src;
 119
 120         jpeg_read_header(&cinfo, 1);
 121         cinfo.out_color_space = JCS_RGB;
 122
 123         if(img_set_pixels(img, cinfo.image_width, cinfo.image_height, IMG_FMT_RGB24, 0) == -1) {
 124                 jpeg_destroy_decompress(&cinfo);
 125                 return -1;
 126         }
 127
 128         if(!(scanlines = malloc(img->height * sizeof *scanlines))) {
 129                 jpeg_destroy_decompress(&cinfo);
 130                 return -1;
 131         }
 132         scanlines[0] = img->pixels;
 133         for(i=1; i<img->height; i++) {
 134                 scanlines[i] = scanlines[i - 1] + img->width * img->pixelsz;
 135         }
 136
 137         jpeg_start_decompress(&cinfo);
 138         while(nlines < img->height) {
 139                 int res = jpeg_read_scanlines(&cinfo, scanlines + nlines, img->height - nlines);
 140                 nlines += res;
 141         }
 142         jpeg_finish_decompress(&cinfo);
 143         jpeg_destroy_decompress(&cinfo);
 144
 145         free(scanlines);
 146         return 0;
 147 }
 148
 149 static int write(struct img_pixmap *img, struct img_io *io)
 150 {
 151         int i, nlines = 0;
 152         struct jpeg_compress_struct cinfo;
 153         struct jpeg_error_mgr jerr;
 154         struct dst_mgr dest;
 155         struct img_pixmap tmpimg;
 156         unsigned char **scanlines;
 157
 158         img_init(&tmpimg);
 159
 160         if(img->fmt != IMG_FMT_RGB24) {
 161                 if(img_copy(&tmpimg, img) == -1) {
 162                         return -1;
 163                 }
 164                 if(img_convert(&tmpimg, IMG_FMT_RGB24) == -1) {
 165                         img_destroy(&tmpimg);
 166                         return -1;
 167                 }
 168                 img = &tmpimg;
 169         }
 170
 171         if(!(scanlines = malloc(img->height * sizeof *scanlines))) {
 172                 img_destroy(&tmpimg);
 173                 return -1;
 174         }
 175         scanlines[0] = img->pixels;
 176         for(i=1; i<img->height; i++) {
 177                 scanlines[i] = scanlines[i - 1] + img->width * img->pixelsz;
 178         }
 179
 180         cinfo.err = jpeg_std_error(&jerr);      /* XXX */
 181         jpeg_create_compress(&cinfo);
 182
 183         dest.pub.init_destination = init_destination;
 184         dest.pub.empty_output_buffer = empty_output_buffer;
 185         dest.pub.term_destination = term_destination;
 186         dest.io = io;
 187         cinfo.dest = (struct jpeg_destination_mgr*)&dest;
 188
 189         cinfo.image_width = img->width;
 190         cinfo.image_height = img->height;
 191         cinfo.input_components = 3;
 192         cinfo.in_color_space = JCS_RGB;
 193
 194         jpeg_set_defaults(&cinfo);
 195         jpeg_set_quality(&cinfo, 95, 0);
 196
 197         jpeg_start_compress(&cinfo, 1);
 198         while(nlines < img->height) {
 199                 int res = jpeg_write_scanlines(&cinfo, scanlines + nlines, img->height - nlines);
 200                 nlines += res;
 201         }
 202         jpeg_finish_compress(&cinfo);
 203         jpeg_destroy_compress(&cinfo);
 204
 205         free(scanlines);
 206         img_destroy(&tmpimg);
 207         return 0;
 208 }
 209
 210 /* -- read source functions --
 211  * the following functions are adapted from jdatasrc.c in jpeglib
 212  */
 213 static void init_source(j_decompress_ptr jd)
 214 {
 215         struct src_mgr *src = (struct src_mgr*)jd->src;
 216         src->start_of_file = 1;
 217 }
 218
 219 static boolean fill_input_buffer(j_decompress_ptr jd)
 220 {
 221         struct src_mgr *src = (struct src_mgr*)jd->src;
 222         size_t nbytes;
 223
 224         nbytes = src->io->read(src->buffer, INPUT_BUF_SIZE, src->io->uptr);
 225
 226         if(nbytes <= 0) {
 227                 if(src->start_of_file) {
 228                         return 0;
 229                 }
 230                 /* insert a fake EOI marker */
 231                 src->buffer[0] = 0xff;
 232                 src->buffer[1] = JPEG_EOI;
 233                 nbytes = 2;
 234         }
 235
 236         src->pub.next_input_byte = src->buffer;
 237         src->pub.bytes_in_buffer = nbytes;
 238         src->start_of_file = 0;
 239         return 1;
 240 }
 241
 242 static void skip_input_data(j_decompress_ptr jd, long num_bytes)
 243 {
 244         struct src_mgr *src = (struct src_mgr*)jd->src;
 245
 246         if(num_bytes > 0) {
 247                 while(num_bytes > (long)src->pub.bytes_in_buffer) {
 248                         num_bytes -= (long)src->pub.bytes_in_buffer;
 249                         fill_input_buffer(jd);
 250                 }
 251                 src->pub.next_input_byte += (size_t)num_bytes;
 252                 src->pub.bytes_in_buffer -= (size_t)num_bytes;
 253         }
 254 }
 255
 256 static void term_source(j_decompress_ptr jd)
 257 {
 258         /* nothing to see here, move along */
 259 }
 260
 261
 262 /* -- write destination functions --
 263  * the following functions are adapted from jdatadst.c in jpeglib
 264  */
 265 static void init_destination(j_compress_ptr jc)
 266 {
 267         struct dst_mgr *dest = (struct dst_mgr*)jc->dest;
 268
 269         dest->pub.next_output_byte = dest->buffer;
 270         dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
 271 }
 272
 273 static boolean empty_output_buffer(j_compress_ptr jc)
 274 {
 275         struct dst_mgr *dest = (struct dst_mgr*)jc->dest;
 276
 277         if(dest->io->write(dest->buffer, OUTPUT_BUF_SIZE, dest->io->uptr) != OUTPUT_BUF_SIZE) {
 278                 return 0;
 279         }
 280
 281         dest->pub.next_output_byte = dest->buffer;
 282         dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
 283         return 1;
 284 }
 285
 286 static void term_destination(j_compress_ptr jc)
 287 {
 288         struct dst_mgr *dest = (struct dst_mgr*)jc->dest;
 289         size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
 290
 291         /* write any remaining data in the buffer */
 292         if(datacount > 0) {
 293                 dest->io->write(dest->buffer, datacount, dest->io->uptr);
 294         }
 295         /* XXX flush? ... */
 296 }
 297
 298 #else
 299 /* build without JPEG support */
 300 int img_register_jpeg(void)
 301 {
 302         return -1;
 303 }
 304 #endif