IMG_jpg.c
author Thomas Bernard <miniupnp@free.fr>
Fri, 30 Nov 2018 11:04:15 +0100
branchSDL-1.2
changeset 634 68f958f43339
parent 607 1a1189c2978f
permissions -rw-r--r--
IMG_xcf.c: Avoid infinite loop in read_xcf_header()
slouken@0
     1
/*
slouken@280
     2
  SDL_image:  An example image loading library for use with SDL
slouken@280
     3
  Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>
slouken@0
     4
slouken@280
     5
  This software is provided 'as-is', without any express or implied
slouken@280
     6
  warranty.  In no event will the authors be held liable for any damages
slouken@280
     7
  arising from the use of this software.
slouken@0
     8
slouken@280
     9
  Permission is granted to anyone to use this software for any purpose,
slouken@280
    10
  including commercial applications, and to alter it and redistribute it
slouken@280
    11
  freely, subject to the following restrictions:
slouken@0
    12
slouken@280
    13
  1. The origin of this software must not be misrepresented; you must not
slouken@280
    14
     claim that you wrote the original software. If you use this software
slouken@280
    15
     in a product, an acknowledgment in the product documentation would be
slouken@280
    16
     appreciated but is not required.
slouken@280
    17
  2. Altered source versions must be plainly marked as such, and must not be
slouken@280
    18
     misrepresented as being the original software.
slouken@280
    19
  3. This notice may not be removed or altered from any source distribution.
slouken@0
    20
*/
slouken@0
    21
slouken@237
    22
#if !defined(__APPLE__) || defined(SDL_IMAGE_USE_COMMON_BACKEND)
slouken@237
    23
slouken@0
    24
/* This is a JPEG image file loading framework */
slouken@0
    25
slouken@0
    26
#include <stdio.h>
slouken@7
    27
#include <string.h>
slouken@61
    28
#include <setjmp.h>
slouken@0
    29
slouken@0
    30
#include "SDL_image.h"
slouken@0
    31
slouken@0
    32
#ifdef LOAD_JPG
slouken@0
    33
slouken@0
    34
#include <jpeglib.h>
slouken@0
    35
slouken@282
    36
#ifdef JPEG_TRUE  /* MinGW version of jpeg-8.x renamed TRUE to JPEG_TRUE etc. */
slouken@273
    37
	typedef JPEG_boolean boolean;
slouken@273
    38
	#define TRUE JPEG_TRUE
slouken@273
    39
	#define FALSE JPEG_FALSE
slouken@273
    40
#endif
slouken@273
    41
slouken@0
    42
/* Define this for fast loading and not as good image quality */
slouken@0
    43
/*#define FAST_JPEG*/
slouken@0
    44
slouken@123
    45
/* Define this for quicker (but less perfect) JPEG identification */
slouken@123
    46
#define FAST_IS_JPEG
slouken@123
    47
slouken@143
    48
static struct {
slouken@143
    49
	int loaded;
slouken@143
    50
	void *handle;
slouken@143
    51
	void (*jpeg_calc_output_dimensions) (j_decompress_ptr cinfo);
slouken@143
    52
	void (*jpeg_CreateDecompress) (j_decompress_ptr cinfo, int version, size_t structsize);
slouken@143
    53
	void (*jpeg_destroy_decompress) (j_decompress_ptr cinfo);
slouken@143
    54
	boolean (*jpeg_finish_decompress) (j_decompress_ptr cinfo);
slouken@143
    55
	int (*jpeg_read_header) (j_decompress_ptr cinfo, boolean require_image);
slouken@143
    56
	JDIMENSION (*jpeg_read_scanlines) (j_decompress_ptr cinfo, JSAMPARRAY scanlines, JDIMENSION max_lines);
slouken@143
    57
	boolean (*jpeg_resync_to_restart) (j_decompress_ptr cinfo, int desired);
slouken@143
    58
	boolean (*jpeg_start_decompress) (j_decompress_ptr cinfo);
slouken@143
    59
	struct jpeg_error_mgr * (*jpeg_std_error) (struct jpeg_error_mgr * err);
slouken@143
    60
} lib;
slouken@143
    61
slouken@143
    62
#ifdef LOAD_JPG_DYNAMIC
slouken@205
    63
int IMG_InitJPG()
slouken@143
    64
{
slouken@143
    65
	if ( lib.loaded == 0 ) {
slouken@143
    66
		lib.handle = SDL_LoadObject(LOAD_JPG_DYNAMIC);
slouken@143
    67
		if ( lib.handle == NULL ) {
slouken@143
    68
			return -1;
slouken@143
    69
		}
slouken@143
    70
		lib.jpeg_calc_output_dimensions =
slouken@143
    71
			(void (*) (j_decompress_ptr))
slouken@143
    72
			SDL_LoadFunction(lib.handle, "jpeg_calc_output_dimensions");
slouken@143
    73
		if ( lib.jpeg_calc_output_dimensions == NULL ) {
slouken@143
    74
			SDL_UnloadObject(lib.handle);
slouken@143
    75
			return -1;
slouken@143
    76
		}
slouken@143
    77
		lib.jpeg_CreateDecompress = 
slouken@143
    78
			(void (*) (j_decompress_ptr, int, size_t))
slouken@143
    79
			SDL_LoadFunction(lib.handle, "jpeg_CreateDecompress");
slouken@143
    80
		if ( lib.jpeg_CreateDecompress == NULL ) {
slouken@143
    81
			SDL_UnloadObject(lib.handle);
slouken@143
    82
			return -1;
slouken@143
    83
		}
slouken@143
    84
		lib.jpeg_destroy_decompress = 
slouken@143
    85
			(void (*) (j_decompress_ptr))
slouken@143
    86
			SDL_LoadFunction(lib.handle, "jpeg_destroy_decompress");
slouken@143
    87
		if ( lib.jpeg_destroy_decompress == NULL ) {
slouken@143
    88
			SDL_UnloadObject(lib.handle);
slouken@143
    89
			return -1;
slouken@143
    90
		}
slouken@143
    91
		lib.jpeg_finish_decompress = 
slouken@143
    92
			(boolean (*) (j_decompress_ptr))
slouken@143
    93
			SDL_LoadFunction(lib.handle, "jpeg_finish_decompress");
slouken@143
    94
		if ( lib.jpeg_finish_decompress == NULL ) {
slouken@143
    95
			SDL_UnloadObject(lib.handle);
slouken@143
    96
			return -1;
slouken@143
    97
		}
slouken@143
    98
		lib.jpeg_read_header = 
slouken@143
    99
			(int (*) (j_decompress_ptr, boolean))
slouken@143
   100
			SDL_LoadFunction(lib.handle, "jpeg_read_header");
slouken@143
   101
		if ( lib.jpeg_read_header == NULL ) {
slouken@143
   102
			SDL_UnloadObject(lib.handle);
slouken@143
   103
			return -1;
slouken@143
   104
		}
slouken@143
   105
		lib.jpeg_read_scanlines = 
slouken@143
   106
			(JDIMENSION (*) (j_decompress_ptr, JSAMPARRAY, JDIMENSION))
slouken@143
   107
			SDL_LoadFunction(lib.handle, "jpeg_read_scanlines");
slouken@143
   108
		if ( lib.jpeg_read_scanlines == NULL ) {
slouken@143
   109
			SDL_UnloadObject(lib.handle);
slouken@143
   110
			return -1;
slouken@143
   111
		}
slouken@143
   112
		lib.jpeg_resync_to_restart = 
slouken@143
   113
			(boolean (*) (j_decompress_ptr, int))
slouken@143
   114
			SDL_LoadFunction(lib.handle, "jpeg_resync_to_restart");
slouken@143
   115
		if ( lib.jpeg_resync_to_restart == NULL ) {
slouken@143
   116
			SDL_UnloadObject(lib.handle);
slouken@143
   117
			return -1;
slouken@143
   118
		}
slouken@143
   119
		lib.jpeg_start_decompress = 
slouken@143
   120
			(boolean (*) (j_decompress_ptr))
slouken@143
   121
			SDL_LoadFunction(lib.handle, "jpeg_start_decompress");
slouken@143
   122
		if ( lib.jpeg_start_decompress == NULL ) {
slouken@143
   123
			SDL_UnloadObject(lib.handle);
slouken@143
   124
			return -1;
slouken@143
   125
		}
slouken@143
   126
		lib.jpeg_std_error = 
slouken@143
   127
			(struct jpeg_error_mgr * (*) (struct jpeg_error_mgr *))
slouken@143
   128
			SDL_LoadFunction(lib.handle, "jpeg_std_error");
slouken@143
   129
		if ( lib.jpeg_std_error == NULL ) {
slouken@143
   130
			SDL_UnloadObject(lib.handle);
slouken@143
   131
			return -1;
slouken@143
   132
		}
slouken@143
   133
	}
slouken@143
   134
	++lib.loaded;
slouken@143
   135
slouken@143
   136
	return 0;
slouken@143
   137
}
slouken@205
   138
void IMG_QuitJPG()
slouken@143
   139
{
slouken@143
   140
	if ( lib.loaded == 0 ) {
slouken@143
   141
		return;
slouken@143
   142
	}
slouken@143
   143
	if ( lib.loaded == 1 ) {
slouken@143
   144
		SDL_UnloadObject(lib.handle);
slouken@143
   145
	}
slouken@143
   146
	--lib.loaded;
slouken@143
   147
}
slouken@143
   148
#else
slouken@205
   149
int IMG_InitJPG()
slouken@143
   150
{
slouken@143
   151
	if ( lib.loaded == 0 ) {
slouken@143
   152
		lib.jpeg_calc_output_dimensions = jpeg_calc_output_dimensions;
slouken@143
   153
		lib.jpeg_CreateDecompress = jpeg_CreateDecompress;
slouken@143
   154
		lib.jpeg_destroy_decompress = jpeg_destroy_decompress;
slouken@143
   155
		lib.jpeg_finish_decompress = jpeg_finish_decompress;
slouken@143
   156
		lib.jpeg_read_header = jpeg_read_header;
slouken@143
   157
		lib.jpeg_read_scanlines = jpeg_read_scanlines;
slouken@143
   158
		lib.jpeg_resync_to_restart = jpeg_resync_to_restart;
slouken@143
   159
		lib.jpeg_start_decompress = jpeg_start_decompress;
slouken@143
   160
		lib.jpeg_std_error = jpeg_std_error;
slouken@143
   161
	}
slouken@143
   162
	++lib.loaded;
slouken@146
   163
slouken@146
   164
	return 0;
slouken@143
   165
}
slouken@205
   166
void IMG_QuitJPG()
slouken@143
   167
{
slouken@143
   168
	if ( lib.loaded == 0 ) {
slouken@143
   169
		return;
slouken@143
   170
	}
slouken@143
   171
	if ( lib.loaded == 1 ) {
slouken@143
   172
	}
slouken@143
   173
	--lib.loaded;
slouken@143
   174
}
slouken@143
   175
#endif /* LOAD_JPG_DYNAMIC */
slouken@143
   176
slouken@0
   177
/* See if an image is contained in a data source */
slouken@0
   178
int IMG_isJPG(SDL_RWops *src)
slouken@0
   179
{
slouken@117
   180
	int start;
slouken@0
   181
	int is_JPG;
slouken@123
   182
	int in_scan;
slouken@0
   183
	Uint8 magic[4];
slouken@0
   184
slouken@123
   185
	/* This detection code is by Steaphan Greene <stea@cs.binghamton.edu> */
slouken@123
   186
	/* Blame me, not Sam, if this doesn't work right. */
slouken@123
   187
	/* And don't forget to report the problem to the the sdl list too! */
slouken@123
   188
icculus@154
   189
	if ( !src )
icculus@154
   190
		return 0;
slouken@117
   191
	start = SDL_RWtell(src);
slouken@0
   192
	is_JPG = 0;
slouken@123
   193
	in_scan = 0;
slouken@0
   194
	if ( SDL_RWread(src, magic, 2, 1) ) {
slouken@0
   195
		if ( (magic[0] == 0xFF) && (magic[1] == 0xD8) ) {
slouken@123
   196
			is_JPG = 1;
slouken@123
   197
			while (is_JPG == 1) {
slouken@123
   198
				if(SDL_RWread(src, magic, 1, 2) != 2) {
slouken@123
   199
					is_JPG = 0;
slouken@123
   200
				} else if( (magic[0] != 0xFF) && (in_scan == 0) ) {
slouken@123
   201
					is_JPG = 0;
slouken@123
   202
				} else if( (magic[0] != 0xFF) || (magic[1] == 0xFF) ) {
slouken@123
   203
					/* Extra padding in JPEG (legal) */
slouken@123
   204
					/* or this is data and we are scanning */
slouken@236
   205
					SDL_RWseek(src, -1, RW_SEEK_CUR);
slouken@123
   206
				} else if(magic[1] == 0xD9) {
slouken@123
   207
					/* Got to end of good JPEG */
slouken@123
   208
					break;
slouken@123
   209
				} else if( (in_scan == 1) && (magic[1] == 0x00) ) {
slouken@123
   210
					/* This is an encoded 0xFF within the data */
slouken@123
   211
				} else if( (magic[1] >= 0xD0) && (magic[1] < 0xD9) ) {
slouken@123
   212
					/* These have nothing else */
slouken@123
   213
				} else if(SDL_RWread(src, magic+2, 1, 2) != 2) {
slouken@123
   214
					is_JPG = 0;
slouken@123
   215
				} else {
slouken@123
   216
					/* Yes, it's big-endian */
sezeroz@607
   217
					Sint32 innerStart;
slouken@123
   218
					Uint32 size;
sezeroz@607
   219
					Sint32 end;
sezeroz@607
   220
					innerStart = SDL_RWtell(src);
slouken@123
   221
					size = (magic[2] << 8) + magic[3];
slouken@236
   222
					end = SDL_RWseek(src, size-2, RW_SEEK_CUR);
sezeroz@607
   223
					if ( end != innerStart + size - 2 ) is_JPG = 0;
slouken@123
   224
					if ( magic[1] == 0xDA ) {
slouken@123
   225
						/* Now comes the actual JPEG meat */
slouken@123
   226
#ifdef	FAST_IS_JPEG
slouken@123
   227
						/* Ok, I'm convinced.  It is a JPEG. */
slouken@123
   228
						break;
slouken@123
   229
#else
slouken@123
   230
						/* I'm not convinced.  Prove it! */
slouken@123
   231
						in_scan = 1;
slouken@123
   232
#endif
slouken@123
   233
					}
slouken@123
   234
				}
slouken@0
   235
			}
slouken@0
   236
		}
slouken@0
   237
	}
slouken@236
   238
	SDL_RWseek(src, start, RW_SEEK_SET);
slouken@0
   239
	return(is_JPG);
slouken@0
   240
}
slouken@0
   241
slouken@0
   242
#define INPUT_BUFFER_SIZE	4096
slouken@0
   243
typedef struct {
slouken@0
   244
	struct jpeg_source_mgr pub;
slouken@0
   245
slouken@0
   246
	SDL_RWops *ctx;
slouken@0
   247
	Uint8 buffer[INPUT_BUFFER_SIZE];
slouken@0
   248
} my_source_mgr;
slouken@0
   249
slouken@0
   250
/*
slouken@0
   251
 * Initialize source --- called by jpeg_read_header
slouken@0
   252
 * before any data is actually read.
slouken@0
   253
 */
slouken@27
   254
static void init_source (j_decompress_ptr cinfo)
slouken@0
   255
{
slouken@0
   256
	/* We don't actually need to do anything */
slouken@0
   257
	return;
slouken@0
   258
}
slouken@0
   259
slouken@0
   260
/*
slouken@0
   261
 * Fill the input buffer --- called whenever buffer is emptied.
slouken@0
   262
 */
slouken@288
   263
static boolean fill_input_buffer (j_decompress_ptr cinfo)
slouken@0
   264
{
slouken@0
   265
	my_source_mgr * src = (my_source_mgr *) cinfo->src;
slouken@0
   266
	int nbytes;
slouken@0
   267
slouken@0
   268
	nbytes = SDL_RWread(src->ctx, src->buffer, 1, INPUT_BUFFER_SIZE);
slouken@0
   269
	if (nbytes <= 0) {
slouken@0
   270
		/* Insert a fake EOI marker */
slouken@0
   271
		src->buffer[0] = (Uint8) 0xFF;
slouken@0
   272
		src->buffer[1] = (Uint8) JPEG_EOI;
slouken@0
   273
		nbytes = 2;
slouken@0
   274
	}
slouken@0
   275
	src->pub.next_input_byte = src->buffer;
slouken@0
   276
	src->pub.bytes_in_buffer = nbytes;
slouken@0
   277
slouken@0
   278
	return TRUE;
slouken@0
   279
}
slouken@0
   280
slouken@0
   281
slouken@0
   282
/*
slouken@0
   283
 * Skip data --- used to skip over a potentially large amount of
slouken@0
   284
 * uninteresting data (such as an APPn marker).
slouken@0
   285
 *
slouken@0
   286
 * Writers of suspendable-input applications must note that skip_input_data
slouken@0
   287
 * is not granted the right to give a suspension return.  If the skip extends
slouken@0
   288
 * beyond the data currently in the buffer, the buffer can be marked empty so
slouken@0
   289
 * that the next read will cause a fill_input_buffer call that can suspend.
slouken@0
   290
 * Arranging for additional bytes to be discarded before reloading the input
slouken@0
   291
 * buffer is the application writer's problem.
slouken@0
   292
 */
slouken@27
   293
static void skip_input_data (j_decompress_ptr cinfo, long num_bytes)
slouken@0
   294
{
slouken@0
   295
	my_source_mgr * src = (my_source_mgr *) cinfo->src;
slouken@0
   296
slouken@0
   297
	/* Just a dumb implementation for now.	Could use fseek() except
slouken@0
   298
	 * it doesn't work on pipes.  Not clear that being smart is worth
slouken@0
   299
	 * any trouble anyway --- large skips are infrequent.
slouken@0
   300
	 */
slouken@0
   301
	if (num_bytes > 0) {
slouken@0
   302
		while (num_bytes > (long) src->pub.bytes_in_buffer) {
slouken@0
   303
			num_bytes -= (long) src->pub.bytes_in_buffer;
slouken@0
   304
			(void) src->pub.fill_input_buffer(cinfo);
slouken@0
   305
			/* note we assume that fill_input_buffer will never
slouken@0
   306
			 * return FALSE, so suspension need not be handled.
slouken@0
   307
			 */
slouken@0
   308
		}
slouken@0
   309
		src->pub.next_input_byte += (size_t) num_bytes;
slouken@0
   310
		src->pub.bytes_in_buffer -= (size_t) num_bytes;
slouken@0
   311
	}
slouken@0
   312
}
slouken@0
   313
slouken@0
   314
/*
slouken@0
   315
 * Terminate source --- called by jpeg_finish_decompress
slouken@0
   316
 * after all data has been read.
slouken@0
   317
 */
slouken@27
   318
static void term_source (j_decompress_ptr cinfo)
slouken@0
   319
{
slouken@0
   320
	/* We don't actually need to do anything */
slouken@0
   321
	return;
slouken@0
   322
}
slouken@0
   323
slouken@0
   324
/*
slouken@0
   325
 * Prepare for input from a stdio stream.
slouken@0
   326
 * The caller must have already opened the stream, and is responsible
slouken@0
   327
 * for closing it after finishing decompression.
slouken@0
   328
 */
slouken@27
   329
static void jpeg_SDL_RW_src (j_decompress_ptr cinfo, SDL_RWops *ctx)
slouken@0
   330
{
slouken@0
   331
  my_source_mgr *src;
slouken@0
   332
slouken@0
   333
  /* The source object and input buffer are made permanent so that a series
slouken@0
   334
   * of JPEG images can be read from the same file by calling jpeg_stdio_src
slouken@0
   335
   * only before the first one.  (If we discarded the buffer at the end of
slouken@0
   336
   * one image, we'd likely lose the start of the next one.)
slouken@0
   337
   * This makes it unsafe to use this manager and a different source
slouken@0
   338
   * manager serially with the same JPEG object.  Caveat programmer.
slouken@0
   339
   */
slouken@0
   340
  if (cinfo->src == NULL) {	/* first time for this JPEG object? */
slouken@0
   341
    cinfo->src = (struct jpeg_source_mgr *)
slouken@0
   342
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
slouken@0
   343
				  sizeof(my_source_mgr));
slouken@0
   344
    src = (my_source_mgr *) cinfo->src;
slouken@0
   345
  }
slouken@0
   346
slouken@0
   347
  src = (my_source_mgr *) cinfo->src;
slouken@27
   348
  src->pub.init_source = init_source;
slouken@27
   349
  src->pub.fill_input_buffer = fill_input_buffer;
slouken@27
   350
  src->pub.skip_input_data = skip_input_data;
slouken@143
   351
  src->pub.resync_to_restart = lib.jpeg_resync_to_restart; /* use default method */
slouken@27
   352
  src->pub.term_source = term_source;
slouken@0
   353
  src->ctx = ctx;
slouken@0
   354
  src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
slouken@0
   355
  src->pub.next_input_byte = NULL; /* until buffer loaded */
slouken@0
   356
}
slouken@0
   357
slouken@61
   358
struct my_error_mgr {
slouken@61
   359
	struct jpeg_error_mgr errmgr;
slouken@61
   360
	jmp_buf escape;
slouken@61
   361
};
slouken@61
   362
slouken@61
   363
static void my_error_exit(j_common_ptr cinfo)
slouken@61
   364
{
slouken@61
   365
	struct my_error_mgr *err = (struct my_error_mgr *)cinfo->err;
slouken@61
   366
	longjmp(err->escape, 1);
slouken@61
   367
}
slouken@61
   368
slouken@61
   369
static void output_no_message(j_common_ptr cinfo)
slouken@61
   370
{
slouken@61
   371
	/* do nothing */
slouken@61
   372
}
slouken@61
   373
slouken@0
   374
/* Load a JPEG type image from an SDL datasource */
slouken@0
   375
SDL_Surface *IMG_LoadJPG_RW(SDL_RWops *src)
slouken@0
   376
{
slouken@118
   377
	int start;
slouken@0
   378
	struct jpeg_decompress_struct cinfo;
slouken@0
   379
	JSAMPROW rowptr[1];
slouken@61
   380
	SDL_Surface *volatile surface = NULL;
slouken@61
   381
	struct my_error_mgr jerr;
slouken@0
   382
slouken@98
   383
	if ( !src ) {
slouken@98
   384
		/* The error message has been set in SDL_RWFromFile */
slouken@98
   385
		return NULL;
slouken@98
   386
	}
slouken@118
   387
	start = SDL_RWtell(src);
slouken@98
   388
sezeroz@607
   389
	if ( (IMG_Init(IMG_INIT_JPG) & IMG_INIT_JPG) == 0 ) {
slouken@143
   390
		return NULL;
slouken@143
   391
	}
slouken@143
   392
slouken@0
   393
	/* Create a decompression structure and load the JPEG header */
slouken@143
   394
	cinfo.err = lib.jpeg_std_error(&jerr.errmgr);
slouken@61
   395
	jerr.errmgr.error_exit = my_error_exit;
slouken@61
   396
	jerr.errmgr.output_message = output_no_message;
slouken@61
   397
	if(setjmp(jerr.escape)) {
slouken@61
   398
		/* If we get here, libjpeg found an error */
slouken@143
   399
		lib.jpeg_destroy_decompress(&cinfo);
slouken@118
   400
		if ( surface != NULL ) {
slouken@118
   401
			SDL_FreeSurface(surface);
slouken@118
   402
		}
slouken@236
   403
		SDL_RWseek(src, start, RW_SEEK_SET);
slouken@61
   404
		IMG_SetError("JPEG loading error");
slouken@61
   405
		return NULL;
slouken@61
   406
	}
slouken@61
   407
slouken@143
   408
	lib.jpeg_create_decompress(&cinfo);
slouken@0
   409
	jpeg_SDL_RW_src(&cinfo, src);
slouken@143
   410
	lib.jpeg_read_header(&cinfo, TRUE);
slouken@0
   411
slouken@123
   412
	if(cinfo.num_components == 4) {
slouken@123
   413
		/* Set 32-bit Raw output */
slouken@123
   414
		cinfo.out_color_space = JCS_CMYK;
slouken@123
   415
		cinfo.quantize_colors = FALSE;
slouken@143
   416
		lib.jpeg_calc_output_dimensions(&cinfo);
slouken@123
   417
slouken@123
   418
		/* Allocate an output surface to hold the image */
slouken@123
   419
		surface = SDL_AllocSurface(SDL_SWSURFACE,
slouken@123
   420
		        cinfo.output_width, cinfo.output_height, 32,
slouken@123
   421
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
slouken@123
   422
		                   0x00FF0000, 0x0000FF00, 0x000000FF, 0xFF000000);
slouken@123
   423
#else
slouken@123
   424
		                   0x0000FF00, 0x00FF0000, 0xFF000000, 0x000000FF);
slouken@123
   425
#endif
slouken@123
   426
	} else {
slouken@123
   427
		/* Set 24-bit RGB output */
slouken@123
   428
		cinfo.out_color_space = JCS_RGB;
slouken@123
   429
		cinfo.quantize_colors = FALSE;
slouken@0
   430
#ifdef FAST_JPEG
slouken@123
   431
		cinfo.scale_num   = 1;
slouken@123
   432
		cinfo.scale_denom = 1;
slouken@123
   433
		cinfo.dct_method = JDCT_FASTEST;
slouken@123
   434
		cinfo.do_fancy_upsampling = FALSE;
slouken@0
   435
#endif
slouken@143
   436
		lib.jpeg_calc_output_dimensions(&cinfo);
slouken@0
   437
slouken@123
   438
		/* Allocate an output surface to hold the image */
slouken@123
   439
		surface = SDL_AllocSurface(SDL_SWSURFACE,
slouken@123
   440
		        cinfo.output_width, cinfo.output_height, 24,
slouken@0
   441
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
slouken@123
   442
		                   0x0000FF, 0x00FF00, 0xFF0000,
slouken@0
   443
#else
slouken@123
   444
		                   0xFF0000, 0x00FF00, 0x0000FF,
slouken@0
   445
#endif
slouken@123
   446
		                   0);
slouken@123
   447
	}
slouken@123
   448
slouken@0
   449
	if ( surface == NULL ) {
slouken@143
   450
		lib.jpeg_destroy_decompress(&cinfo);
slouken@236
   451
		SDL_RWseek(src, start, RW_SEEK_SET);
slouken@0
   452
		IMG_SetError("Out of memory");
slouken@118
   453
		return NULL;
slouken@0
   454
	}
slouken@0
   455
slouken@0
   456
	/* Decompress the image */
slouken@143
   457
	lib.jpeg_start_decompress(&cinfo);
slouken@0
   458
	while ( cinfo.output_scanline < cinfo.output_height ) {
slouken@0
   459
		rowptr[0] = (JSAMPROW)(Uint8 *)surface->pixels +
slouken@0
   460
		                    cinfo.output_scanline * surface->pitch;
slouken@143
   461
		lib.jpeg_read_scanlines(&cinfo, rowptr, (JDIMENSION) 1);
slouken@0
   462
	}
slouken@143
   463
	lib.jpeg_finish_decompress(&cinfo);
slouken@143
   464
	lib.jpeg_destroy_decompress(&cinfo);
slouken@143
   465
slouken@0
   466
	return(surface);
slouken@0
   467
}
slouken@0
   468
slouken@0
   469
#else
slouken@0
   470
slouken@205
   471
int IMG_InitJPG()
slouken@205
   472
{
slouken@205
   473
	IMG_SetError("JPEG images are not supported");
slouken@205
   474
	return(-1);
slouken@205
   475
}
slouken@205
   476
slouken@205
   477
void IMG_QuitJPG()
slouken@205
   478
{
slouken@205
   479
}
slouken@205
   480
slouken@0
   481
/* See if an image is contained in a data source */
slouken@0
   482
int IMG_isJPG(SDL_RWops *src)
slouken@0
   483
{
slouken@0
   484
	return(0);
slouken@0
   485
}
slouken@0
   486
slouken@0
   487
/* Load a JPEG type image from an SDL datasource */
slouken@0
   488
SDL_Surface *IMG_LoadJPG_RW(SDL_RWops *src)
slouken@0
   489
{
slouken@0
   490
	return(NULL);
slouken@0
   491
}
slouken@0
   492
slouken@0
   493
#endif /* LOAD_JPG */
slouken@237
   494
slouken@237
   495
#endif /* !defined(__APPLE__) || defined(SDL_IMAGE_USE_COMMON_BACKEND) */