jpeg.c

   1 /*
   2         Copyright (C) 2002  Mathieu Olivier
   3
   4         This program is free software; you can redistribute it and/or
   5         modify it under the terms of the GNU General Public License
   6         as published by the Free Software Foundation; either version 2
   7         of the License, or (at your option) any later version.
   8
   9         This program is distributed in the hope that it will be useful,
  10         but WITHOUT ANY WARRANTY; without even the implied warranty of
  11         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  12
  13         See the GNU General Public License for more details.
  14
  15         You should have received a copy of the GNU General Public License
  16         along with this program; if not, write to:
  17
  18                 Free Software Foundation, Inc.
  19                 59 Temple Place - Suite 330
  20                 Boston, MA  02111-1307, USA
  21
  22 */
  23
  24
  25 #include "quakedef.h"
  26 #include "image.h"
  27 #include "jpeg.h"
  28
  29
  30 /*
  31 =================================================================
  32
  33   Minimal set of definitions from the JPEG lib
  34
  35   WARNING: for a matter of simplicity, several pointer types are
  36   casted to "void*", and most enumerated values are not included
  37
  38 =================================================================
  39 */
  40
  41 // jboolean is qbyte instead of int on Win32
  42 #ifdef WIN32
  43 typedef qbyte jboolean;
  44 #else
  45 typedef int jboolean;
  46 #endif
  47
  48 #define JPEG_LIB_VERSION  62  // Version 6b
  49
  50 typedef void *j_common_ptr;
  51 typedef struct jpeg_compress_struct *j_compress_ptr;
  52 typedef struct jpeg_decompress_struct *j_decompress_ptr;
  53 typedef enum
  54 {
  55         JCS_UNKNOWN,
  56         JCS_GRAYSCALE,
  57         JCS_RGB,
  58         JCS_YCbCr,
  59         JCS_CMYK,
  60         JCS_YCCK
  61 } J_COLOR_SPACE;
  62 typedef enum {JPEG_DUMMY1} J_DCT_METHOD;
  63 typedef enum {JPEG_DUMMY2} J_DITHER_MODE;
  64 typedef unsigned int JDIMENSION;
  65
  66 #define JPOOL_PERMANENT 0       // lasts until master record is destroyed
  67 #define JPOOL_IMAGE             1       // lasts until done with image/datastream
  68
  69 #define JPEG_EOI        0xD9  // EOI marker code
  70
  71 #define JMSG_STR_PARM_MAX  80
  72
  73 #define DCTSIZE2 64
  74 #define NUM_QUANT_TBLS 4
  75 #define NUM_HUFF_TBLS 4
  76 #define NUM_ARITH_TBLS 16
  77 #define MAX_COMPS_IN_SCAN 4
  78 #define C_MAX_BLOCKS_IN_MCU 10
  79 #define D_MAX_BLOCKS_IN_MCU 10
  80
  81 struct jpeg_memory_mgr
  82 {
  83   void* (*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject);
  84   void (*alloc_large) ();
  85   void (*alloc_sarray) ();
  86   void (*alloc_barray) ();
  87   void (*request_virt_sarray) ();
  88   void (*request_virt_barray) ();
  89   void (*realize_virt_arrays) ();
  90   void (*access_virt_sarray) ();
  91   void (*access_virt_barray) ();
  92   void (*free_pool) ();
  93   void (*self_destruct) ();
  94
  95   long max_memory_to_use;
  96   long max_alloc_chunk;
  97 };
  98
  99 struct jpeg_error_mgr
 100 {
 101         void (*error_exit) (j_common_ptr cinfo);
 102         void (*emit_message) (j_common_ptr cinfo, int msg_level);
 103         void (*output_message) (j_common_ptr cinfo);
 104         void (*format_message) (j_common_ptr cinfo, char * buffer);
 105         void (*reset_error_mgr) (j_common_ptr cinfo);
 106         int msg_code;
 107         union {
 108                 int i[8];
 109                 char s[JMSG_STR_PARM_MAX];
 110         } msg_parm;
 111         int trace_level;
 112         long num_warnings;
 113         const char * const * jpeg_message_table;
 114         int last_jpeg_message;
 115         const char * const * addon_message_table;
 116         int first_addon_message;
 117         int last_addon_message;
 118 };
 119
 120 struct jpeg_source_mgr
 121 {
 122         const qbyte *next_input_byte;
 123         size_t bytes_in_buffer;
 124
 125         void (*init_source) (j_decompress_ptr cinfo);
 126         jboolean (*fill_input_buffer) (j_decompress_ptr cinfo);
 127         void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes);
 128         jboolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired);
 129         void (*term_source) (j_decompress_ptr cinfo);
 130 };
 131
 132 struct jpeg_decompress_struct
 133 {
 134         struct jpeg_error_mgr *err;             // USED
 135         struct jpeg_memory_mgr *mem;    // USED
 136
 137         void *progress;
 138         void *client_data;
 139         jboolean is_decompressor;
 140         int global_state;
 141
 142         struct jpeg_source_mgr *src;    // USED
 143         JDIMENSION image_width;                 // USED
 144         JDIMENSION image_height;                // USED
 145
 146         int num_components;
 147         J_COLOR_SPACE jpeg_color_space;
 148         J_COLOR_SPACE out_color_space;
 149         unsigned int scale_num, scale_denom;
 150         double output_gamma;
 151         jboolean buffered_image;
 152         jboolean raw_data_out;
 153         J_DCT_METHOD dct_method;
 154         jboolean do_fancy_upsampling;
 155         jboolean do_block_smoothing;
 156         jboolean quantize_colors;
 157         J_DITHER_MODE dither_mode;
 158         jboolean two_pass_quantize;
 159         int desired_number_of_colors;
 160         jboolean enable_1pass_quant;
 161         jboolean enable_external_quant;
 162         jboolean enable_2pass_quant;
 163         JDIMENSION output_width;
 164
 165         JDIMENSION output_height;       // USED
 166
 167         int out_color_components;
 168
 169         int output_components;          // USED
 170
 171         int rec_outbuf_height;
 172         int actual_number_of_colors;
 173         void *colormap;
 174
 175         JDIMENSION output_scanline;     // USED
 176
 177         int input_scan_number;
 178         JDIMENSION input_iMCU_row;
 179         int output_scan_number;
 180         JDIMENSION output_iMCU_row;
 181         int (*coef_bits)[DCTSIZE2];
 182         void *quant_tbl_ptrs[NUM_QUANT_TBLS];
 183         void *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
 184         void *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
 185         int data_precision;
 186         void *comp_info;
 187         jboolean progressive_mode;
 188         jboolean arith_code;
 189         qbyte arith_dc_L[NUM_ARITH_TBLS];
 190         qbyte arith_dc_U[NUM_ARITH_TBLS];
 191         qbyte arith_ac_K[NUM_ARITH_TBLS];
 192         unsigned int restart_interval;
 193         jboolean saw_JFIF_marker;
 194         qbyte JFIF_major_version;
 195         qbyte JFIF_minor_version;
 196         qbyte density_unit;
 197         unsigned short X_density;
 198         unsigned short Y_density;
 199         jboolean saw_Adobe_marker;
 200         qbyte Adobe_transform;
 201         jboolean CCIR601_sampling;
 202         void *marker_list;
 203         int max_h_samp_factor;
 204         int max_v_samp_factor;
 205         int min_DCT_scaled_size;
 206         JDIMENSION total_iMCU_rows;
 207         void *sample_range_limit;
 208         int comps_in_scan;
 209         void *cur_comp_info[MAX_COMPS_IN_SCAN];
 210         JDIMENSION MCUs_per_row;
 211         JDIMENSION MCU_rows_in_scan;
 212         int blocks_in_MCU;
 213         int MCU_membership[D_MAX_BLOCKS_IN_MCU];
 214         int Ss, Se, Ah, Al;
 215         int unread_marker;
 216         void *master;
 217         void *main;
 218         void *coef;
 219         void *post;
 220         void *inputctl;
 221         void *marker;
 222         void *entropy;
 223         void *idct;
 224         void *upsample;
 225         void *cconvert;
 226         void *cquantize;
 227 };
 228
 229
 230 struct jpeg_compress_struct
 231 {
 232         struct jpeg_error_mgr *err;
 233         struct jpeg_memory_mgr *mem;
 234         void *progress;
 235         void *client_data;
 236         jboolean is_decompressor;
 237         int global_state;
 238
 239         void *dest;
 240         JDIMENSION image_width;
 241         JDIMENSION image_height;
 242         int input_components;
 243         J_COLOR_SPACE in_color_space;
 244         double input_gamma;
 245         int data_precision;
 246
 247         int num_components;
 248         J_COLOR_SPACE jpeg_color_space;
 249         void *comp_info;
 250         void *quant_tbl_ptrs[NUM_QUANT_TBLS];
 251         void *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
 252         void *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
 253         qbyte arith_dc_L[NUM_ARITH_TBLS];
 254         qbyte arith_dc_U[NUM_ARITH_TBLS];
 255         qbyte arith_ac_K[NUM_ARITH_TBLS];
 256
 257         int num_scans;
 258         const void *scan_info;
 259         jboolean raw_data_in;
 260         jboolean arith_code;
 261         jboolean optimize_coding;
 262         jboolean CCIR601_sampling;
 263         int smoothing_factor;
 264         J_DCT_METHOD dct_method;
 265
 266         unsigned int restart_interval;
 267         int restart_in_rows;
 268
 269         jboolean write_JFIF_header;
 270         qbyte JFIF_major_version;
 271         qbyte JFIF_minor_version;
 272         qbyte density_unit;
 273         unsigned short X_density;
 274         unsigned short Y_density;
 275         jboolean write_Adobe_marker;
 276         JDIMENSION next_scanline;
 277
 278         jboolean progressive_mode;
 279         int max_h_samp_factor;
 280         int max_v_samp_factor;
 281         JDIMENSION total_iMCU_rows;
 282         int comps_in_scan;
 283         void *cur_comp_info[MAX_COMPS_IN_SCAN];
 284         JDIMENSION MCUs_per_row;
 285         JDIMENSION MCU_rows_in_scan;
 286         int blocks_in_MCU;
 287         int MCU_membership[C_MAX_BLOCKS_IN_MCU];
 288         int Ss, Se, Ah, Al;
 289
 290         void *master;
 291         void *main;
 292         void *prep;
 293         void *coef;
 294         void *marker;
 295         void *cconvert;
 296         void *downsample;
 297         void *fdct;
 298         void *entropy;
 299         void *script_space;
 300         int script_space_size;
 301 };
 302
 303 struct jpeg_destination_mgr
 304 {
 305         qbyte* next_output_byte;
 306         size_t free_in_buffer;
 307
 308         void (*init_destination) (j_compress_ptr cinfo);
 309         jboolean (*empty_output_buffer) (j_compress_ptr cinfo);
 310         void (*term_destination) (j_compress_ptr cinfo);
 311 };
 312
 313
 314 /*
 315 =================================================================
 316
 317   DarkPlaces definitions
 318
 319 =================================================================
 320 */
 321
 322 // Functions exported from libjpeg
 323 #define qjpeg_create_compress(cinfo) \
 324         qjpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, (size_t) sizeof(struct jpeg_compress_struct))
 325 #define qjpeg_create_decompress(cinfo) \
 326         qjpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, (size_t) sizeof(struct jpeg_decompress_struct))
 327
 328 static void (*qjpeg_CreateCompress) (j_compress_ptr cinfo, int version, size_t structsize);
 329 static void (*qjpeg_CreateDecompress) (j_decompress_ptr cinfo, int version, size_t structsize);
 330 static void (*qjpeg_destroy_compress) (j_compress_ptr cinfo);
 331 static void (*qjpeg_destroy_decompress) (j_decompress_ptr cinfo);
 332 static void (*qjpeg_finish_compress) (j_compress_ptr cinfo);
 333 static jboolean (*qjpeg_finish_decompress) (j_decompress_ptr cinfo);
 334 static jboolean (*qjpeg_resync_to_restart) (j_decompress_ptr cinfo, int desired);
 335 static int (*qjpeg_read_header) (j_decompress_ptr cinfo, jboolean require_image);
 336 static JDIMENSION (*qjpeg_read_scanlines) (j_decompress_ptr cinfo, qbyte** scanlines, JDIMENSION max_lines);
 337 static void (*qjpeg_set_defaults) (j_compress_ptr cinfo);
 338 static void (*qjpeg_set_quality) (j_compress_ptr cinfo, int quality, jboolean force_baseline);
 339 static jboolean (*qjpeg_start_compress) (j_compress_ptr cinfo, jboolean write_all_tables);
 340 static jboolean (*qjpeg_start_decompress) (j_decompress_ptr cinfo);
 341 static struct jpeg_error_mgr* (*qjpeg_std_error) (struct jpeg_error_mgr *err);
 342 static JDIMENSION (*qjpeg_write_scanlines) (j_compress_ptr cinfo, qbyte** scanlines, JDIMENSION num_lines);
 343
 344 static dllfunction_t jpegfuncs[] =
 345 {
 346         {"jpeg_CreateCompress",         (void **) &qjpeg_CreateCompress},
 347         {"jpeg_CreateDecompress",       (void **) &qjpeg_CreateDecompress},
 348         {"jpeg_destroy_compress",       (void **) &qjpeg_destroy_compress},
 349         {"jpeg_destroy_decompress",     (void **) &qjpeg_destroy_decompress},
 350         {"jpeg_finish_compress",        (void **) &qjpeg_finish_compress},
 351         {"jpeg_finish_decompress",      (void **) &qjpeg_finish_decompress},
 352         {"jpeg_resync_to_restart",      (void **) &qjpeg_resync_to_restart},
 353         {"jpeg_read_header",            (void **) &qjpeg_read_header},
 354         {"jpeg_read_scanlines",         (void **) &qjpeg_read_scanlines},
 355         {"jpeg_set_defaults",           (void **) &qjpeg_set_defaults},
 356         {"jpeg_set_quality",            (void **) &qjpeg_set_quality},
 357         {"jpeg_start_compress",         (void **) &qjpeg_start_compress},
 358         {"jpeg_start_decompress",       (void **) &qjpeg_start_decompress},
 359         {"jpeg_std_error",                      (void **) &qjpeg_std_error},
 360         {"jpeg_write_scanlines",        (void **) &qjpeg_write_scanlines},
 361         {NULL, NULL}
 362 };
 363
 364 // Handle for JPEG DLL
 365 dllhandle_t jpeg_dll = NULL;
 366
 367 static qbyte jpeg_eoi_marker [2] = {0xFF, JPEG_EOI};
 368 static qboolean error_in_jpeg;
 369
 370 // Our own output manager for JPEG compression
 371 typedef struct
 372 {
 373         struct jpeg_destination_mgr pub;
 374
 375         qfile_t* outfile;
 376         qbyte* buffer;
 377 } my_destination_mgr;
 378 typedef my_destination_mgr* my_dest_ptr;
 379
 380
 381 /*
 382 =================================================================
 383
 384   DLL load & unload
 385
 386 =================================================================
 387 */
 388
 389 /*
 390 ====================
 391 JPEG_OpenLibrary
 392
 393 Try to load the JPEG DLL
 394 ====================
 395 */
 396 qboolean JPEG_OpenLibrary (void)
 397 {
 398         const char* dllnames [] =
 399         {
 400 #ifdef WIN32
 401                 "libjpeg.dll",
 402 #elif defined(MACOSX)
 403                 "libjpeg.62.dylib",
 404 #else
 405                 "libjpeg.so.62",
 406                 "libjpeg.so",
 407 #endif
 408                 NULL
 409         };
 410
 411         // Already loaded?
 412         if (jpeg_dll)
 413                 return true;
 414
 415         // Load the DLL
 416         if (! Sys_LoadLibrary (dllnames, &jpeg_dll, jpegfuncs))
 417         {
 418                 Con_Printf ("JPEG support disabled\n");
 419                 return false;
 420         }
 421
 422         Con_Printf ("JPEG support enabled\n");
 423         return true;
 424 }
 425
 426
 427 /*
 428 ====================
 429 JPEG_CloseLibrary
 430
 431 Unload the JPEG DLL
 432 ====================
 433 */
 434 void JPEG_CloseLibrary (void)
 435 {
 436         Sys_UnloadLibrary (&jpeg_dll);
 437 }
 438
 439
 440 /*
 441 =================================================================
 442
 443         JPEG decompression
 444
 445 =================================================================
 446 */
 447
 448 static void JPEG_Noop (j_decompress_ptr cinfo) {}
 449
 450 static jboolean JPEG_FillInputBuffer (j_decompress_ptr cinfo)
 451 {
 452     // Insert a fake EOI marker
 453     cinfo->src->next_input_byte = jpeg_eoi_marker;
 454     cinfo->src->bytes_in_buffer = 2;
 455
 456         return TRUE;
 457 }
 458
 459 static void JPEG_SkipInputData (j_decompress_ptr cinfo, long num_bytes)
 460 {
 461     if (cinfo->src->bytes_in_buffer <= (unsigned long)num_bytes)
 462         {
 463                 cinfo->src->bytes_in_buffer = 0;
 464                 return;
 465         }
 466
 467     cinfo->src->next_input_byte += num_bytes;
 468     cinfo->src->bytes_in_buffer -= num_bytes;
 469 }
 470
 471 static void JPEG_MemSrc (j_decompress_ptr cinfo, const qbyte *buffer)
 472 {
 473         cinfo->src = cinfo->mem->alloc_small ((j_common_ptr) cinfo, JPOOL_PERMANENT, sizeof (struct jpeg_source_mgr));
 474
 475         cinfo->src->next_input_byte = buffer;
 476         cinfo->src->bytes_in_buffer = fs_filesize;
 477
 478         cinfo->src->init_source = JPEG_Noop;
 479         cinfo->src->fill_input_buffer = JPEG_FillInputBuffer;
 480         cinfo->src->skip_input_data = JPEG_SkipInputData;
 481         cinfo->src->resync_to_restart = qjpeg_resync_to_restart; // use the default method
 482         cinfo->src->term_source = JPEG_Noop;
 483 }
 484
 485 static void JPEG_ErrorExit (j_common_ptr cinfo)
 486 {
 487         ((struct jpeg_decompress_struct*)cinfo)->err->output_message (cinfo);
 488         error_in_jpeg = true;
 489 }
 490
 491
 492 /*
 493 ====================
 494 JPEG_LoadImage
 495
 496 Load a JPEG image into a RGBA buffer
 497 ====================
 498 */
 499 qbyte* JPEG_LoadImage (const qbyte *f, int matchwidth, int matchheight)
 500 {
 501         struct jpeg_decompress_struct cinfo;
 502         struct jpeg_error_mgr jerr;
 503         qbyte *image_rgba, *scanline;
 504         unsigned int line;
 505
 506         // No DLL = no JPEGs
 507         if (!jpeg_dll)
 508                 return NULL;
 509
 510         cinfo.err = qjpeg_std_error (&jerr);
 511         qjpeg_create_decompress (&cinfo);
 512         JPEG_MemSrc (&cinfo, f);
 513         qjpeg_read_header (&cinfo, TRUE);
 514         qjpeg_start_decompress (&cinfo);
 515
 516         image_width = cinfo.image_width;
 517         image_height = cinfo.image_height;
 518
 519         if ((matchwidth && image_width != matchwidth) || (matchheight && image_height != matchheight))
 520         {
 521                 qjpeg_finish_decompress (&cinfo);
 522                 qjpeg_destroy_decompress (&cinfo);
 523                 return NULL;
 524         }
 525         if (image_width > 4096 || image_height > 4096 || image_width <= 0 || image_height <= 0)
 526         {
 527                 Con_Printf("JPEG_LoadImage: invalid image size %ix%i\n", image_width, image_height);
 528                 return NULL;
 529         }
 530
 531         image_rgba = Mem_Alloc(tempmempool, image_width * image_height * 4);
 532         scanline = Mem_Alloc(tempmempool, image_width * cinfo.output_components);
 533         if (!image_rgba || !scanline)
 534         {
 535                 if (!image_rgba)
 536                         Mem_Free (image_rgba);
 537
 538                 Con_Printf("JPEG_LoadImage: not enough memory for %i by %i image\n", image_width, image_height);
 539                 qjpeg_finish_decompress (&cinfo);
 540                 qjpeg_destroy_decompress (&cinfo);
 541                 return NULL;
 542         }
 543
 544         // Decompress the image, line by line
 545         line = 0;
 546         while (cinfo.output_scanline < cinfo.output_height)
 547         {
 548                 qbyte *buffer_ptr;
 549                 int ind;
 550
 551                 qjpeg_read_scanlines (&cinfo, &scanline, 1);
 552
 553                 // Convert the image to RGBA
 554                 switch (cinfo.output_components)
 555                 {
 556                         // RGB images
 557                         case 3:
 558                                 buffer_ptr = &image_rgba[image_width * line * 4];
 559                                 for (ind = 0; ind < image_width * 3; ind += 3, buffer_ptr += 4)
 560                                 {
 561                                         buffer_ptr[0] = scanline[ind];
 562                                         buffer_ptr[1] = scanline[ind + 1];
 563                                         buffer_ptr[2] = scanline[ind + 2];
 564                                         buffer_ptr[3] = 255;
 565                                 }
 566                                 break;
 567
 568                         // Greyscale images (default to it, just in case)
 569                         case 1:
 570                         default:
 571                                 buffer_ptr = &image_rgba[image_width * line * 4];
 572                                 for (ind = 0; ind < image_width; ind++, buffer_ptr += 4)
 573                                 {
 574                                         buffer_ptr[0] = scanline[ind];
 575                                         buffer_ptr[1] = scanline[ind];
 576                                         buffer_ptr[2] = scanline[ind];
 577                                         buffer_ptr[3] = 255;
 578                                 }
 579                 }
 580
 581                 line++;
 582         }
 583         Mem_Free (scanline);
 584
 585         qjpeg_finish_decompress (&cinfo);
 586         qjpeg_destroy_decompress (&cinfo);
 587
 588         return image_rgba;
 589 }
 590
 591
 592 /*
 593 =================================================================
 594
 595   JPEG compression
 596
 597 =================================================================
 598 */
 599
 600 #define JPEG_OUTPUT_BUF_SIZE 4096
 601 static void JPEG_InitDestination (j_compress_ptr cinfo)
 602 {
 603         my_dest_ptr dest = (my_dest_ptr)cinfo->dest;
 604         dest->buffer = (qbyte*)cinfo->mem->alloc_small ((j_common_ptr) cinfo, JPOOL_IMAGE, JPEG_OUTPUT_BUF_SIZE * sizeof(qbyte));
 605         dest->pub.next_output_byte = dest->buffer;
 606         dest->pub.free_in_buffer = JPEG_OUTPUT_BUF_SIZE;
 607 }
 608
 609 static jboolean JPEG_EmptyOutputBuffer (j_compress_ptr cinfo)
 610 {
 611         my_dest_ptr dest = (my_dest_ptr)cinfo->dest;
 612
 613         if (FS_Write (dest->outfile, dest->buffer, JPEG_OUTPUT_BUF_SIZE) != (size_t) JPEG_OUTPUT_BUF_SIZE)
 614         {
 615                 error_in_jpeg = true;
 616                 return false;
 617         }
 618
 619         dest->pub.next_output_byte = dest->buffer;
 620         dest->pub.free_in_buffer = JPEG_OUTPUT_BUF_SIZE;
 621         return true;
 622 }
 623
 624 static void JPEG_TermDestination (j_compress_ptr cinfo)
 625 {
 626         my_dest_ptr dest = (my_dest_ptr)cinfo->dest;
 627         size_t datacount = JPEG_OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
 628
 629         // Write any data remaining in the buffer
 630         if (datacount > 0)
 631                 if (FS_Write (dest->outfile, dest->buffer, datacount) != datacount)
 632                         error_in_jpeg = true;
 633 }
 634
 635 static void JPEG_MemDest (j_compress_ptr cinfo, qfile_t* outfile)
 636 {
 637         my_dest_ptr dest;
 638
 639         // First time for this JPEG object?
 640         if (cinfo->dest == NULL)
 641                 cinfo->dest = (struct jpeg_destination_mgr *)(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, sizeof(my_destination_mgr));
 642
 643         dest = (my_dest_ptr)cinfo->dest;
 644         dest->pub.init_destination = JPEG_InitDestination;
 645         dest->pub.empty_output_buffer = JPEG_EmptyOutputBuffer;
 646         dest->pub.term_destination = JPEG_TermDestination;
 647         dest->outfile = outfile;
 648 }
 649
 650
 651 /*
 652 ====================
 653 JPEG_SaveImage_preflipped
 654
 655 Save a preflipped JPEG image to a file
 656 ====================
 657 */
 658 qboolean JPEG_SaveImage_preflipped (const char *filename, int width, int height, qbyte *data)
 659 {
 660         struct jpeg_compress_struct cinfo;
 661         struct jpeg_error_mgr jerr;
 662         qbyte *scanline;
 663         unsigned int offset, linesize;
 664         qfile_t* file;
 665
 666         // No DLL = no JPEGs
 667         if (!jpeg_dll)
 668         {
 669                 Con_Print("You need the libjpeg library to save JPEG images\n");
 670                 return false;
 671         }
 672
 673         // Open the file
 674         file = FS_Open (filename, "wb", true, false);
 675         if (!file)
 676                 return false;
 677
 678         cinfo.err = qjpeg_std_error (&jerr);
 679         cinfo.err->error_exit = JPEG_ErrorExit;
 680         error_in_jpeg = false;
 681
 682         qjpeg_create_compress (&cinfo);
 683         JPEG_MemDest (&cinfo, file);
 684
 685         // Set the parameters for compression
 686         cinfo.image_width = width;
 687         cinfo.image_height = height;
 688         cinfo.in_color_space = JCS_RGB;
 689         cinfo.input_components = 3;
 690         qjpeg_set_defaults (&cinfo);
 691         qjpeg_set_quality (&cinfo, scr_screenshot_jpeg_quality.value * 100, TRUE);
 692         qjpeg_start_compress (&cinfo, true);
 693
 694         // Compress each scanline
 695         linesize = cinfo.image_width * 3;
 696         offset = linesize * (cinfo.image_height - 1);
 697         while (cinfo.next_scanline < cinfo.image_height)
 698         {
 699                 scanline = &data[offset - cinfo.next_scanline * linesize];
 700
 701                 qjpeg_write_scanlines (&cinfo, &scanline, 1);
 702                 if (error_in_jpeg)
 703                         break;
 704         }
 705
 706         qjpeg_finish_compress (&cinfo);
 707         qjpeg_destroy_compress (&cinfo);
 708
 709         FS_Close (file);
 710         return true;
 711 }