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 unsigned char instead of int on Win32
  42 #ifdef WIN32
  43 typedef unsigned char 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 unsigned char *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 typedef struct {
 133   /* These values are fixed over the whole image. */
 134   /* For compression, they must be supplied by parameter setup; */
 135   /* for decompression, they are read from the SOF marker. */
 136   int component_id;             /* identifier for this component (0..255) */
 137   int component_index;          /* its index in SOF or cinfo->comp_info[] */
 138   int h_samp_factor;            /* horizontal sampling factor (1..4) */
 139   int v_samp_factor;            /* vertical sampling factor (1..4) */
 140   int quant_tbl_no;             /* quantization table selector (0..3) */
 141   /* These values may vary between scans. */
 142   /* For compression, they must be supplied by parameter setup; */
 143   /* for decompression, they are read from the SOS marker. */
 144   /* The decompressor output side may not use these variables. */
 145   int dc_tbl_no;                /* DC entropy table selector (0..3) */
 146   int ac_tbl_no;                /* AC entropy table selector (0..3) */
 147
 148   /* Remaining fields should be treated as private by applications. */
 149
 150   /* These values are computed during compression or decompression startup: */
 151   /* Component's size in DCT blocks.
 152    * Any dummy blocks added to complete an MCU are not counted; therefore
 153    * these values do not depend on whether a scan is interleaved or not.
 154    */
 155   JDIMENSION width_in_blocks;
 156   JDIMENSION height_in_blocks;
 157   /* Size of a DCT block in samples.  Always DCTSIZE for compression.
 158    * For decompression this is the size of the output from one DCT block,
 159    * reflecting any scaling we choose to apply during the IDCT step.
 160    * Values of 1,2,4,8 are likely to be supported.  Note that different
 161    * components may receive different IDCT scalings.
 162    */
 163   int DCT_scaled_size;
 164   /* The downsampled dimensions are the component's actual, unpadded number
 165    * of samples at the main buffer (preprocessing/compression interface), thus
 166    * downsampled_width = ceil(image_width * Hi/Hmax)
 167    * and similarly for height.  For decompression, IDCT scaling is included, so
 168    * downsampled_width = ceil(image_width * Hi/Hmax * DCT_scaled_size/DCTSIZE)
 169    */
 170   JDIMENSION downsampled_width;  /* actual width in samples */
 171   JDIMENSION downsampled_height; /* actual height in samples */
 172   /* This flag is used only for decompression.  In cases where some of the
 173    * components will be ignored (eg grayscale output from YCbCr image),
 174    * we can skip most computations for the unused components.
 175    */
 176   jboolean component_needed;     /* do we need the value of this component? */
 177
 178   /* These values are computed before starting a scan of the component. */
 179   /* The decompressor output side may not use these variables. */
 180   int MCU_width;                /* number of blocks per MCU, horizontally */
 181   int MCU_height;               /* number of blocks per MCU, vertically */
 182   int MCU_blocks;               /* MCU_width * MCU_height */
 183   int MCU_sample_width;         /* MCU width in samples, MCU_width*DCT_scaled_size */
 184   int last_col_width;           /* # of non-dummy blocks across in last MCU */
 185   int last_row_height;          /* # of non-dummy blocks down in last MCU */
 186
 187   /* Saved quantization table for component; NULL if none yet saved.
 188    * See jdinput.c comments about the need for this information.
 189    * This field is currently used only for decompression.
 190    */
 191   void *quant_table;
 192
 193   /* Private per-component storage for DCT or IDCT subsystem. */
 194   void * dct_table;
 195 } jpeg_component_info;
 196
 197 struct jpeg_decompress_struct
 198 {
 199         struct jpeg_error_mgr *err;             // USED
 200         struct jpeg_memory_mgr *mem;    // USED
 201
 202         void *progress;
 203         void *client_data;
 204         jboolean is_decompressor;
 205         int global_state;
 206
 207         struct jpeg_source_mgr *src;    // USED
 208         JDIMENSION image_width;                 // USED
 209         JDIMENSION image_height;                // USED
 210
 211         int num_components;
 212         J_COLOR_SPACE jpeg_color_space;
 213         J_COLOR_SPACE out_color_space;
 214         unsigned int scale_num, scale_denom;
 215         double output_gamma;
 216         jboolean buffered_image;
 217         jboolean raw_data_out;
 218         J_DCT_METHOD dct_method;
 219         jboolean do_fancy_upsampling;
 220         jboolean do_block_smoothing;
 221         jboolean quantize_colors;
 222         J_DITHER_MODE dither_mode;
 223         jboolean two_pass_quantize;
 224         int desired_number_of_colors;
 225         jboolean enable_1pass_quant;
 226         jboolean enable_external_quant;
 227         jboolean enable_2pass_quant;
 228         JDIMENSION output_width;
 229
 230         JDIMENSION output_height;       // USED
 231
 232         int out_color_components;
 233
 234         int output_components;          // USED
 235
 236         int rec_outbuf_height;
 237         int actual_number_of_colors;
 238         void *colormap;
 239
 240         JDIMENSION output_scanline;     // USED
 241
 242         int input_scan_number;
 243         JDIMENSION input_iMCU_row;
 244         int output_scan_number;
 245         JDIMENSION output_iMCU_row;
 246         int (*coef_bits)[DCTSIZE2];
 247         void *quant_tbl_ptrs[NUM_QUANT_TBLS];
 248         void *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
 249         void *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
 250         int data_precision;
 251         jpeg_component_info *comp_info;
 252         jboolean progressive_mode;
 253         jboolean arith_code;
 254         unsigned char arith_dc_L[NUM_ARITH_TBLS];
 255         unsigned char arith_dc_U[NUM_ARITH_TBLS];
 256         unsigned char arith_ac_K[NUM_ARITH_TBLS];
 257         unsigned int restart_interval;
 258         jboolean saw_JFIF_marker;
 259         unsigned char JFIF_major_version;
 260         unsigned char JFIF_minor_version;
 261         unsigned char density_unit;
 262         unsigned short X_density;
 263         unsigned short Y_density;
 264         jboolean saw_Adobe_marker;
 265         unsigned char Adobe_transform;
 266         jboolean CCIR601_sampling;
 267         void *marker_list;
 268         int max_h_samp_factor;
 269         int max_v_samp_factor;
 270         int min_DCT_scaled_size;
 271         JDIMENSION total_iMCU_rows;
 272         void *sample_range_limit;
 273         int comps_in_scan;
 274         jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
 275         JDIMENSION MCUs_per_row;
 276         JDIMENSION MCU_rows_in_scan;
 277         int blocks_in_MCU;
 278         int MCU_membership[D_MAX_BLOCKS_IN_MCU];
 279         int Ss, Se, Ah, Al;
 280         int unread_marker;
 281         void *master;
 282         void *main;
 283         void *coef;
 284         void *post;
 285         void *inputctl;
 286         void *marker;
 287         void *entropy;
 288         void *idct;
 289         void *upsample;
 290         void *cconvert;
 291         void *cquantize;
 292 };
 293
 294
 295 struct jpeg_compress_struct
 296 {
 297         struct jpeg_error_mgr *err;
 298         struct jpeg_memory_mgr *mem;
 299         void *progress;
 300         void *client_data;
 301         jboolean is_decompressor;
 302         int global_state;
 303
 304         void *dest;
 305         JDIMENSION image_width;
 306         JDIMENSION image_height;
 307         int input_components;
 308         J_COLOR_SPACE in_color_space;
 309         double input_gamma;
 310         int data_precision;
 311
 312         int num_components;
 313         J_COLOR_SPACE jpeg_color_space;
 314         jpeg_component_info *comp_info;
 315         void *quant_tbl_ptrs[NUM_QUANT_TBLS];
 316         void *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
 317         void *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
 318         unsigned char arith_dc_L[NUM_ARITH_TBLS];
 319         unsigned char arith_dc_U[NUM_ARITH_TBLS];
 320         unsigned char arith_ac_K[NUM_ARITH_TBLS];
 321
 322         int num_scans;
 323         const void *scan_info;
 324         jboolean raw_data_in;
 325         jboolean arith_code;
 326         jboolean optimize_coding;
 327         jboolean CCIR601_sampling;
 328         int smoothing_factor;
 329         J_DCT_METHOD dct_method;
 330
 331         unsigned int restart_interval;
 332         int restart_in_rows;
 333
 334         jboolean write_JFIF_header;
 335         unsigned char JFIF_major_version;
 336         unsigned char JFIF_minor_version;
 337         unsigned char density_unit;
 338         unsigned short X_density;
 339         unsigned short Y_density;
 340         jboolean write_Adobe_marker;
 341         JDIMENSION next_scanline;
 342
 343         jboolean progressive_mode;
 344         int max_h_samp_factor;
 345         int max_v_samp_factor;
 346         JDIMENSION total_iMCU_rows;
 347         int comps_in_scan;
 348         jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
 349         JDIMENSION MCUs_per_row;
 350         JDIMENSION MCU_rows_in_scan;
 351         int blocks_in_MCU;
 352         int MCU_membership[C_MAX_BLOCKS_IN_MCU];
 353         int Ss, Se, Ah, Al;
 354
 355         void *master;
 356         void *main;
 357         void *prep;
 358         void *coef;
 359         void *marker;
 360         void *cconvert;
 361         void *downsample;
 362         void *fdct;
 363         void *entropy;
 364         void *script_space;
 365         int script_space_size;
 366 };
 367
 368 struct jpeg_destination_mgr
 369 {
 370         unsigned char* next_output_byte;
 371         size_t free_in_buffer;
 372
 373         void (*init_destination) (j_compress_ptr cinfo);
 374         jboolean (*empty_output_buffer) (j_compress_ptr cinfo);
 375         void (*term_destination) (j_compress_ptr cinfo);
 376 };
 377
 378
 379 /*
 380 =================================================================
 381
 382   DarkPlaces definitions
 383
 384 =================================================================
 385 */
 386
 387 // Functions exported from libjpeg
 388 #define qjpeg_create_compress(cinfo) \
 389         qjpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, (size_t) sizeof(struct jpeg_compress_struct))
 390 #define qjpeg_create_decompress(cinfo) \
 391         qjpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, (size_t) sizeof(struct jpeg_decompress_struct))
 392
 393 static void (*qjpeg_CreateCompress) (j_compress_ptr cinfo, int version, size_t structsize);
 394 static void (*qjpeg_CreateDecompress) (j_decompress_ptr cinfo, int version, size_t structsize);
 395 static void (*qjpeg_destroy_compress) (j_compress_ptr cinfo);
 396 static void (*qjpeg_destroy_decompress) (j_decompress_ptr cinfo);
 397 static void (*qjpeg_finish_compress) (j_compress_ptr cinfo);
 398 static jboolean (*qjpeg_finish_decompress) (j_decompress_ptr cinfo);
 399 static jboolean (*qjpeg_resync_to_restart) (j_decompress_ptr cinfo, int desired);
 400 static int (*qjpeg_read_header) (j_decompress_ptr cinfo, jboolean require_image);
 401 static JDIMENSION (*qjpeg_read_scanlines) (j_decompress_ptr cinfo, unsigned char** scanlines, JDIMENSION max_lines);
 402 static void (*qjpeg_set_defaults) (j_compress_ptr cinfo);
 403 static void (*qjpeg_set_quality) (j_compress_ptr cinfo, int quality, jboolean force_baseline);
 404 static jboolean (*qjpeg_start_compress) (j_compress_ptr cinfo, jboolean write_all_tables);
 405 static jboolean (*qjpeg_start_decompress) (j_decompress_ptr cinfo);
 406 static struct jpeg_error_mgr* (*qjpeg_std_error) (struct jpeg_error_mgr *err);
 407 static JDIMENSION (*qjpeg_write_scanlines) (j_compress_ptr cinfo, unsigned char** scanlines, JDIMENSION num_lines);
 408
 409 static dllfunction_t jpegfuncs[] =
 410 {
 411         {"jpeg_CreateCompress",         (void **) &qjpeg_CreateCompress},
 412         {"jpeg_CreateDecompress",       (void **) &qjpeg_CreateDecompress},
 413         {"jpeg_destroy_compress",       (void **) &qjpeg_destroy_compress},
 414         {"jpeg_destroy_decompress",     (void **) &qjpeg_destroy_decompress},
 415         {"jpeg_finish_compress",        (void **) &qjpeg_finish_compress},
 416         {"jpeg_finish_decompress",      (void **) &qjpeg_finish_decompress},
 417         {"jpeg_resync_to_restart",      (void **) &qjpeg_resync_to_restart},
 418         {"jpeg_read_header",            (void **) &qjpeg_read_header},
 419         {"jpeg_read_scanlines",         (void **) &qjpeg_read_scanlines},
 420         {"jpeg_set_defaults",           (void **) &qjpeg_set_defaults},
 421         {"jpeg_set_quality",            (void **) &qjpeg_set_quality},
 422         {"jpeg_start_compress",         (void **) &qjpeg_start_compress},
 423         {"jpeg_start_decompress",       (void **) &qjpeg_start_decompress},
 424         {"jpeg_std_error",                      (void **) &qjpeg_std_error},
 425         {"jpeg_write_scanlines",        (void **) &qjpeg_write_scanlines},
 426         {NULL, NULL}
 427 };
 428
 429 // Handle for JPEG DLL
 430 dllhandle_t jpeg_dll = NULL;
 431
 432 static unsigned char jpeg_eoi_marker [2] = {0xFF, JPEG_EOI};
 433 static qboolean error_in_jpeg;
 434
 435 // Our own output manager for JPEG compression
 436 typedef struct
 437 {
 438         struct jpeg_destination_mgr pub;
 439
 440         qfile_t* outfile;
 441         unsigned char* buffer;
 442 } my_destination_mgr;
 443 typedef my_destination_mgr* my_dest_ptr;
 444
 445
 446 /*
 447 =================================================================
 448
 449   DLL load & unload
 450
 451 =================================================================
 452 */
 453
 454 /*
 455 ====================
 456 JPEG_OpenLibrary
 457
 458 Try to load the JPEG DLL
 459 ====================
 460 */
 461 qboolean JPEG_OpenLibrary (void)
 462 {
 463         const char* dllnames [] =
 464         {
 465 #if defined(WIN64)
 466                 "libjpeg64.dll",
 467 #elif defined(WIN32)
 468                 "libjpeg.dll",
 469 #elif defined(MACOSX)
 470                 "libjpeg.62.dylib",
 471 #else
 472                 "libjpeg.so.62",
 473                 "libjpeg.so",
 474 #endif
 475                 NULL
 476         };
 477
 478         // Already loaded?
 479         if (jpeg_dll)
 480                 return true;
 481
 482         // Load the DLL
 483         return Sys_LoadLibrary (dllnames, &jpeg_dll, jpegfuncs);
 484 }
 485
 486
 487 /*
 488 ====================
 489 JPEG_CloseLibrary
 490
 491 Unload the JPEG DLL
 492 ====================
 493 */
 494 void JPEG_CloseLibrary (void)
 495 {
 496         Sys_UnloadLibrary (&jpeg_dll);
 497 }
 498
 499
 500 /*
 501 =================================================================
 502
 503         JPEG decompression
 504
 505 =================================================================
 506 */
 507
 508 static void JPEG_Noop (j_decompress_ptr cinfo) {}
 509
 510 static jboolean JPEG_FillInputBuffer (j_decompress_ptr cinfo)
 511 {
 512     // Insert a fake EOI marker
 513     cinfo->src->next_input_byte = jpeg_eoi_marker;
 514     cinfo->src->bytes_in_buffer = 2;
 515
 516         return TRUE;
 517 }
 518
 519 static void JPEG_SkipInputData (j_decompress_ptr cinfo, long num_bytes)
 520 {
 521     if (cinfo->src->bytes_in_buffer <= (unsigned long)num_bytes)
 522         {
 523                 cinfo->src->bytes_in_buffer = 0;
 524                 return;
 525         }
 526
 527     cinfo->src->next_input_byte += num_bytes;
 528     cinfo->src->bytes_in_buffer -= num_bytes;
 529 }
 530
 531 static void JPEG_MemSrc (j_decompress_ptr cinfo, const unsigned char *buffer, size_t filesize)
 532 {
 533         cinfo->src = (struct jpeg_source_mgr *)cinfo->mem->alloc_small ((j_common_ptr) cinfo, JPOOL_PERMANENT, sizeof (struct jpeg_source_mgr));
 534
 535         cinfo->src->next_input_byte = buffer;
 536         cinfo->src->bytes_in_buffer = filesize;
 537
 538         cinfo->src->init_source = JPEG_Noop;
 539         cinfo->src->fill_input_buffer = JPEG_FillInputBuffer;
 540         cinfo->src->skip_input_data = JPEG_SkipInputData;
 541         cinfo->src->resync_to_restart = qjpeg_resync_to_restart; // use the default method
 542         cinfo->src->term_source = JPEG_Noop;
 543 }
 544
 545 static void JPEG_ErrorExit (j_common_ptr cinfo)
 546 {
 547         ((struct jpeg_decompress_struct*)cinfo)->err->output_message (cinfo);
 548         error_in_jpeg = true;
 549 }
 550
 551
 552 /*
 553 ====================
 554 JPEG_LoadImage
 555
 556 Load a JPEG image into a BGRA buffer
 557 ====================
 558 */
 559 unsigned char* JPEG_LoadImage_BGRA (const unsigned char *f, int filesize)
 560 {
 561         struct jpeg_decompress_struct cinfo;
 562         struct jpeg_error_mgr jerr;
 563         unsigned char *image_buffer, *scanline;
 564         unsigned int line;
 565
 566         // No DLL = no JPEGs
 567         if (!jpeg_dll)
 568                 return NULL;
 569
 570         cinfo.err = qjpeg_std_error (&jerr);
 571         qjpeg_create_decompress (&cinfo);
 572         JPEG_MemSrc (&cinfo, f, filesize);
 573         qjpeg_read_header (&cinfo, TRUE);
 574         qjpeg_start_decompress (&cinfo);
 575
 576         image_width = cinfo.image_width;
 577         image_height = cinfo.image_height;
 578
 579         if (image_width > 4096 || image_height > 4096 || image_width <= 0 || image_height <= 0)
 580         {
 581                 Con_Printf("JPEG_LoadImage: invalid image size %ix%i\n", image_width, image_height);
 582                 return NULL;
 583         }
 584
 585         image_buffer = (unsigned char *)Mem_Alloc(tempmempool, image_width * image_height * 4);
 586         scanline = (unsigned char *)Mem_Alloc(tempmempool, image_width * cinfo.output_components);
 587         if (!image_buffer || !scanline)
 588         {
 589                 if (image_buffer)
 590                         Mem_Free (image_buffer);
 591                 if (scanline)
 592                         Mem_Free (scanline);
 593
 594                 Con_Printf("JPEG_LoadImage: not enough memory for %i by %i image\n", image_width, image_height);
 595                 qjpeg_finish_decompress (&cinfo);
 596                 qjpeg_destroy_decompress (&cinfo);
 597                 return NULL;
 598         }
 599
 600         // Decompress the image, line by line
 601         line = 0;
 602         while (cinfo.output_scanline < cinfo.output_height)
 603         {
 604                 unsigned char *buffer_ptr;
 605                 int ind;
 606
 607                 qjpeg_read_scanlines (&cinfo, &scanline, 1);
 608
 609                 // Convert the image to BGRA
 610                 switch (cinfo.output_components)
 611                 {
 612                         // RGB images
 613                         case 3:
 614                                 buffer_ptr = &image_buffer[image_width * line * 4];
 615                                 for (ind = 0; ind < image_width * 3; ind += 3, buffer_ptr += 4)
 616                                 {
 617                                         buffer_ptr[2] = scanline[ind];
 618                                         buffer_ptr[1] = scanline[ind + 1];
 619                                         buffer_ptr[0] = scanline[ind + 2];
 620                                         buffer_ptr[3] = 255;
 621                                 }
 622                                 break;
 623
 624                         // Greyscale images (default to it, just in case)
 625                         case 1:
 626                         default:
 627                                 buffer_ptr = &image_buffer[image_width * line * 4];
 628                                 for (ind = 0; ind < image_width; ind++, buffer_ptr += 4)
 629                                 {
 630                                         buffer_ptr[0] = scanline[ind];
 631                                         buffer_ptr[1] = scanline[ind];
 632                                         buffer_ptr[2] = scanline[ind];
 633                                         buffer_ptr[3] = 255;
 634                                 }
 635                 }
 636
 637                 line++;
 638         }
 639         Mem_Free (scanline);
 640
 641         qjpeg_finish_decompress (&cinfo);
 642         qjpeg_destroy_decompress (&cinfo);
 643
 644         return image_buffer;
 645 }
 646
 647
 648 /*
 649 =================================================================
 650
 651   JPEG compression
 652
 653 =================================================================
 654 */
 655
 656 #define JPEG_OUTPUT_BUF_SIZE 4096
 657 static void JPEG_InitDestination (j_compress_ptr cinfo)
 658 {
 659         my_dest_ptr dest = (my_dest_ptr)cinfo->dest;
 660         dest->buffer = (unsigned char*)cinfo->mem->alloc_small ((j_common_ptr) cinfo, JPOOL_IMAGE, JPEG_OUTPUT_BUF_SIZE * sizeof(unsigned char));
 661         dest->pub.next_output_byte = dest->buffer;
 662         dest->pub.free_in_buffer = JPEG_OUTPUT_BUF_SIZE;
 663 }
 664
 665 static jboolean JPEG_EmptyOutputBuffer (j_compress_ptr cinfo)
 666 {
 667         my_dest_ptr dest = (my_dest_ptr)cinfo->dest;
 668
 669         if (FS_Write (dest->outfile, dest->buffer, JPEG_OUTPUT_BUF_SIZE) != (size_t) JPEG_OUTPUT_BUF_SIZE)
 670         {
 671                 error_in_jpeg = true;
 672                 return false;
 673         }
 674
 675         dest->pub.next_output_byte = dest->buffer;
 676         dest->pub.free_in_buffer = JPEG_OUTPUT_BUF_SIZE;
 677         return true;
 678 }
 679
 680 static void JPEG_TermDestination (j_compress_ptr cinfo)
 681 {
 682         my_dest_ptr dest = (my_dest_ptr)cinfo->dest;
 683         size_t datacount = JPEG_OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
 684
 685         // Write any data remaining in the buffer
 686         if (datacount > 0)
 687                 if (FS_Write (dest->outfile, dest->buffer, datacount) != (fs_offset_t)datacount)
 688                         error_in_jpeg = true;
 689 }
 690
 691 static void JPEG_MemDest (j_compress_ptr cinfo, qfile_t* outfile)
 692 {
 693         my_dest_ptr dest;
 694
 695         // First time for this JPEG object?
 696         if (cinfo->dest == NULL)
 697                 cinfo->dest = (struct jpeg_destination_mgr *)(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, sizeof(my_destination_mgr));
 698
 699         dest = (my_dest_ptr)cinfo->dest;
 700         dest->pub.init_destination = JPEG_InitDestination;
 701         dest->pub.empty_output_buffer = JPEG_EmptyOutputBuffer;
 702         dest->pub.term_destination = JPEG_TermDestination;
 703         dest->outfile = outfile;
 704 }
 705
 706
 707 /*
 708 ====================
 709 JPEG_SaveImage_preflipped
 710
 711 Save a preflipped JPEG image to a file
 712 ====================
 713 */
 714 qboolean JPEG_SaveImage_preflipped (const char *filename, int width, int height, unsigned char *data)
 715 {
 716         struct jpeg_compress_struct cinfo;
 717         struct jpeg_error_mgr jerr;
 718         unsigned char *scanline;
 719         unsigned int offset, linesize;
 720         qfile_t* file;
 721
 722         // No DLL = no JPEGs
 723         if (!jpeg_dll)
 724         {
 725                 Con_Print("You need the libjpeg library to save JPEG images\n");
 726                 return false;
 727         }
 728
 729         // Open the file
 730         file = FS_Open (filename, "wb", true, false);
 731         if (!file)
 732                 return false;
 733
 734         cinfo.err = qjpeg_std_error (&jerr);
 735         cinfo.err->error_exit = JPEG_ErrorExit;
 736         error_in_jpeg = false;
 737
 738         qjpeg_create_compress (&cinfo);
 739         JPEG_MemDest (&cinfo, file);
 740
 741         // Set the parameters for compression
 742         cinfo.image_width = width;
 743         cinfo.image_height = height;
 744         cinfo.in_color_space = JCS_RGB;
 745         cinfo.input_components = 3;
 746         qjpeg_set_defaults (&cinfo);
 747         qjpeg_set_quality (&cinfo, (int)(scr_screenshot_jpeg_quality.value * 100), TRUE);
 748
 749         // turn off subsampling (to make text look better)
 750         cinfo.optimize_coding = 1;
 751         cinfo.comp_info[0].h_samp_factor = 1;
 752         cinfo.comp_info[0].v_samp_factor = 1;
 753         cinfo.comp_info[1].h_samp_factor = 1;
 754         cinfo.comp_info[1].v_samp_factor = 1;
 755         cinfo.comp_info[2].h_samp_factor = 1;
 756         cinfo.comp_info[2].v_samp_factor = 1;
 757
 758         qjpeg_start_compress (&cinfo, true);
 759
 760         // Compress each scanline
 761         linesize = cinfo.image_width * 3;
 762         offset = linesize * (cinfo.image_height - 1);
 763         while (cinfo.next_scanline < cinfo.image_height)
 764         {
 765                 scanline = &data[offset - cinfo.next_scanline * linesize];
 766
 767                 qjpeg_write_scanlines (&cinfo, &scanline, 1);
 768                 if (error_in_jpeg)
 769                         break;
 770         }
 771
 772         qjpeg_finish_compress (&cinfo);
 773         qjpeg_destroy_compress (&cinfo);
 774
 775         FS_Close (file);
 776         return true;
 777 }