stb_image.c revision 1.10
1/* stbi-1.29 - public domain JPEG/PNG reader - http://nothings.org/stb_image.c 2 when you control the images you're loading 3 no warranty implied; use at your own risk 4 5 QUICK NOTES: 6 Primarily of interest to game developers and other people who can 7 avoid problematic images and only need the trivial interface 8 9 JPEG baseline (no JPEG progressive) 10 PNG 8-bit only 11 12 TGA (not sure what subset, if a subset) 13 BMP non-1bpp, non-RLE 14 PSD (composited view only, no extra channels) 15 16 GIF (*comp always reports as 4-channel) 17 HDR (radiance rgbE format) 18 PIC (Softimage PIC) 19 20 - decoded from memory or through stdio FILE (define STBI_NO_STDIO to remove code) 21 - supports installable dequantizing-IDCT, YCbCr-to-RGB conversion (define STBI_SIMD) 22 23 Latest revisions: 24 1.29 (2010-08-16) various warning fixes from Aurelien Pocheville 25 1.28 (2010-08-01) fix bug in GIF palette transparency (SpartanJ) 26 1.27 (2010-08-01) cast-to-uint8 to fix warnings (Laurent Gomila) 27 allow trailing 0s at end of image data (Laurent Gomila) 28 1.26 (2010-07-24) fix bug in file buffering for PNG reported by SpartanJ 29 1.25 (2010-07-17) refix trans_data warning (Won Chun) 30 1.24 (2010-07-12) perf improvements reading from files 31 minor perf improvements for jpeg 32 deprecated type-specific functions in hope of feedback 33 attempt to fix trans_data warning (Won Chun) 34 1.23 fixed bug in iPhone support 35 1.22 (2010-07-10) removed image *writing* support to stb_image_write.h 36 stbi_info support from Jetro Lauha 37 GIF support from Jean-Marc Lienher 38 iPhone PNG-extensions from James Brown 39 warning-fixes from Nicolas Schulz and Janez Zemva 40 1.21 fix use of 'uint8' in header (reported by jon blow) 41 1.20 added support for Softimage PIC, by Tom Seddon 42 43 See end of file for full revision history. 44 45 TODO: 46 stbi_info support for BMP,PSD,HDR,PIC 47 rewrite stbi_info and load_file variations to share file handling code 48 (current system allows individual functions to be called directly, 49 since each does all the work, but I doubt anyone uses this in practice) 50 51 52 ============================ Contributors ========================= 53 54 Image formats Optimizations & bugfixes 55 Sean Barrett (jpeg, png, bmp) Fabian "ryg" Giesen 56 Nicolas Schulz (hdr, psd) 57 Jonathan Dummer (tga) Bug fixes & warning fixes 58 Jean-Marc Lienher (gif) Marc LeBlanc 59 Tom Seddon (pic) Christpher Lloyd 60 Thatcher Ulrich (psd) Dave Moore 61 Won Chun 62 the Horde3D community 63 Extensions, features Janez Zemva 64 Jetro Lauha (stbi_info) Jonathan Blow 65 James "moose2000" Brown (iPhone PNG) Laurent Gomila 66 Aruelien Pocheville 67 68 If your name should be here but isn't, let Sean know. 69 70*/ 71 72#ifdef _KERNEL 73#include <dev/stbi/stbiconfig.h> 74#endif 75 76#ifndef STBI_INCLUDE_STB_IMAGE_H 77#define STBI_INCLUDE_STB_IMAGE_H 78 79// To get a header file for this, either cut and paste the header, 80// or create stb_image.h, #define STBI_HEADER_FILE_ONLY, and 81// then include stb_image.c from it. 82 83//// begin header file //////////////////////////////////////////////////// 84// 85// Limitations: 86// - no jpeg progressive support 87// - non-HDR formats support 8-bit samples only (jpeg, png) 88// - no delayed line count (jpeg) -- IJG doesn't support either 89// - no 1-bit BMP 90// - GIF always returns *comp=4 91// 92// Basic usage (see HDR discussion below): 93// int x,y,n; 94// unsigned char *data = stbi_load(filename, &x, &y, &n, 0); 95// // ... process data if not NULL ... 96// // ... x = width, y = height, n = # 8-bit components per pixel ... 97// // ... replace '0' with '1'..'4' to force that many components per pixel 98// stbi_image_free(data) 99// 100// Standard parameters: 101// int *x -- outputs image width in pixels 102// int *y -- outputs image height in pixels 103// int *comp -- outputs # of image components in image file 104// int req_comp -- if non-zero, # of image components requested in result 105// 106// The return value from an image loader is an 'unsigned char *' which points 107// to the pixel data. The pixel data consists of *y scanlines of *x pixels, 108// with each pixel consisting of N interleaved 8-bit components; the first 109// pixel pointed to is top-left-most in the image. There is no padding between 110// image scanlines or between pixels, regardless of format. The number of 111// components N is 'req_comp' if req_comp is non-zero, or *comp otherwise. 112// If req_comp is non-zero, *comp has the number of components that _would_ 113// have been output otherwise. E.g. if you set req_comp to 4, you will always 114// get RGBA output, but you can check *comp to easily see if it's opaque. 115// 116// An output image with N components has the following components interleaved 117// in this order in each pixel: 118// 119// N=#comp components 120// 1 grey 121// 2 grey, alpha 122// 3 red, green, blue 123// 4 red, green, blue, alpha 124// 125// If image loading fails for any reason, the return value will be NULL, 126// and *x, *y, *comp will be unchanged. The function stbi_failure_reason() 127// can be queried for an extremely brief, end-user unfriendly explanation 128// of why the load failed. Define STBI_NO_FAILURE_STRINGS to avoid 129// compiling these strings at all, and STBI_FAILURE_USERMSG to get slightly 130// more user-friendly ones. 131// 132// Paletted PNG, BMP, GIF, and PIC images are automatically depalettized. 133// 134// =========================================================================== 135// 136// iPhone PNG support: 137// 138// By default we convert iphone-formatted PNGs back to RGB; nominally they 139// would silently load as BGR, except the existing code should have just 140// failed on such iPhone PNGs. But you can disable this conversion by 141// by calling stbi_convert_iphone_png_to_rgb(0), in which case 142// you will always just get the native iphone "format" through. 143// 144// Call stbi_set_unpremultiply_on_load(1) as well to force a divide per 145// pixel to remove any premultiplied alpha *only* if the image file explicitly 146// says there's premultiplied data (currently only happens in iPhone images, 147// and only if iPhone convert-to-rgb processing is on). 148// 149// =========================================================================== 150// 151// HDR image support (disable by defining STBI_NO_HDR) 152// 153// stb_image now supports loading HDR images in general, and currently 154// the Radiance .HDR file format, although the support is provided 155// generically. You can still load any file through the existing interface; 156// if you attempt to load an HDR file, it will be automatically remapped to 157// LDR, assuming gamma 2.2 and an arbitrary scale factor defaulting to 1; 158// both of these constants can be reconfigured through this interface: 159// 160// stbi_hdr_to_ldr_gamma(2.2f); 161// stbi_hdr_to_ldr_scale(1.0f); 162// 163// (note, do not use _inverse_ constants; stbi_image will invert them 164// appropriately). 165// 166// Additionally, there is a new, parallel interface for loading files as 167// (linear) floats to preserve the full dynamic range: 168// 169// float *data = stbi_loadf(filename, &x, &y, &n, 0); 170// 171// If you load LDR images through this interface, those images will 172// be promoted to floating point values, run through the inverse of 173// constants corresponding to the above: 174// 175// stbi_ldr_to_hdr_scale(1.0f); 176// stbi_ldr_to_hdr_gamma(2.2f); 177// 178// Finally, given a filename (or an open file or memory block--see header 179// file for details) containing image data, you can query for the "most 180// appropriate" interface to use (that is, whether the image is HDR or 181// not), using: 182// 183// stbi_is_hdr(char *filename); 184 185#ifndef STBI_NO_STDIO 186#include <stdio.h> 187#endif 188 189#define STBI_VERSION 1 190 191enum 192{ 193 STBI_default = 0, // only used for req_comp 194 195 STBI_grey = 1, 196 STBI_grey_alpha = 2, 197 STBI_rgb = 3, 198 STBI_rgb_alpha = 4 199}; 200 201typedef unsigned char stbi_uc; 202 203#ifdef __cplusplus 204extern "C" { 205#endif 206 207// PRIMARY API - works on images of any type 208 209// load image by filename, open file, or memory buffer 210extern stbi_uc *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 211 212#ifndef STBI_NO_STDIO 213extern stbi_uc *stbi_load (char const *filename, int *x, int *y, int *comp, int req_comp); 214extern stbi_uc *stbi_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 215// for stbi_load_from_file, file pointer is left pointing immediately after image 216#endif 217 218#ifndef STBI_NO_HDR 219 extern float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 220 221 #ifndef STBI_NO_STDIO 222 extern float *stbi_loadf (char const *filename, int *x, int *y, int *comp, int req_comp); 223 extern float *stbi_loadf_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 224 #endif 225 226 extern void stbi_hdr_to_ldr_gamma(float gamma); 227 extern void stbi_hdr_to_ldr_scale(float scale); 228 229 extern void stbi_ldr_to_hdr_gamma(float gamma); 230 extern void stbi_ldr_to_hdr_scale(float scale); 231#endif // STBI_NO_HDR 232 233// get a VERY brief reason for failure 234// NOT THREADSAFE 235extern const char *stbi_failure_reason (void); 236 237// free the loaded image -- this is just free() 238extern void stbi_image_free (void *retval_from_stbi_load); 239 240// get image dimensions & components without fully decoding 241extern int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); 242extern int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len); 243 244#ifndef STBI_NO_STDIO 245extern int stbi_info (char const *filename, int *x, int *y, int *comp); 246extern int stbi_info_from_file (FILE *f, int *x, int *y, int *comp); 247 248extern int stbi_is_hdr (char const *filename); 249extern int stbi_is_hdr_from_file(FILE *f); 250#endif 251 252// for image formats that explicitly notate that they have premultiplied alpha, 253// we just return the colors as stored in the file. set this flag to force 254// unpremultiplication. results are undefined if the unpremultiply overflow. 255extern void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply); 256 257// indicate whether we should process iphone images back to canonical format, 258// or just pass them through "as-is" 259extern void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert); 260 261 262// ZLIB client - used by PNG, available for other purposes 263 264extern char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen); 265extern char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header); 266extern char *stbi_zlib_decode_malloc(const char *buffer, int len, int *outlen); 267extern int stbi_zlib_decode_buffer(char *obuffer, int olen, const char *ibuffer, int ilen); 268 269extern char *stbi_zlib_decode_noheader_malloc(const char *buffer, int len, int *outlen); 270extern int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen); 271 272// define new loaders 273typedef struct 274{ 275 int (*test_memory)(stbi_uc const *buffer, int len); 276 stbi_uc * (*load_from_memory)(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 277 #ifndef STBI_NO_STDIO 278 int (*test_file)(FILE *f); 279 stbi_uc * (*load_from_file)(FILE *f, int *x, int *y, int *comp, int req_comp); 280 #endif 281} stbi_loader; 282 283// register a loader by filling out the above structure (you must define ALL functions) 284// returns 1 if added or already added, 0 if not added (too many loaders) 285// NOT THREADSAFE 286extern int stbi_register_loader(stbi_loader *loader); 287 288// define faster low-level operations (typically SIMD support) 289#ifdef STBI_SIMD 290typedef void (*stbi_idct_8x8)(stbi_uc *out, int out_stride, short data[64], unsigned short *dequantize); 291// compute an integer IDCT on "input" 292// input[x] = data[x] * dequantize[x] 293// write results to 'out': 64 samples, each run of 8 spaced by 'out_stride' 294// CLAMP results to 0..255 295typedef void (*stbi_YCbCr_to_RGB_run)(stbi_uc *output, stbi_uc const *y, stbi_uc const *cb, stbi_uc const *cr, int count, int step); 296// compute a conversion from YCbCr to RGB 297// 'count' pixels 298// write pixels to 'output'; each pixel is 'step' bytes (either 3 or 4; if 4, write '255' as 4th), order R,G,B 299// y: Y input channel 300// cb: Cb input channel; scale/biased to be 0..255 301// cr: Cr input channel; scale/biased to be 0..255 302 303extern void stbi_install_idct(stbi_idct_8x8 func); 304extern void stbi_install_YCbCr_to_RGB(stbi_YCbCr_to_RGB_run func); 305#endif // STBI_SIMD 306 307 308 309 310// TYPE-SPECIFIC ACCESS 311 312#ifdef STBI_TYPE_SPECIFIC_FUNCTIONS 313 314// is it a jpeg? 315extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len); 316extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 317extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); 318 319#ifndef STBI_NO_STDIO 320extern stbi_uc *stbi_jpeg_load (char const *filename, int *x, int *y, int *comp, int req_comp); 321extern int stbi_jpeg_test_file (FILE *f); 322extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 323 324extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp); 325extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp); 326#endif 327 328// is it a png? 329extern int stbi_png_test_memory (stbi_uc const *buffer, int len); 330extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 331extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); 332 333#ifndef STBI_NO_STDIO 334extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp); 335extern int stbi_png_info (char const *filename, int *x, int *y, int *comp); 336extern int stbi_png_test_file (FILE *f); 337extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 338extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp); 339#endif 340 341// is it a bmp? 342extern int stbi_bmp_test_memory (stbi_uc const *buffer, int len); 343 344extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp); 345extern stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 346#ifndef STBI_NO_STDIO 347extern int stbi_bmp_test_file (FILE *f); 348extern stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 349#endif 350 351// is it a tga? 352extern int stbi_tga_test_memory (stbi_uc const *buffer, int len); 353 354extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp); 355extern stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 356extern int stbi_tga_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); 357#ifndef STBI_NO_STDIO 358extern int stbi_tga_info_from_file (FILE *f, int *x, int *y, int *comp); 359extern int stbi_tga_test_file (FILE *f); 360extern stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 361#endif 362 363// is it a psd? 364extern int stbi_psd_test_memory (stbi_uc const *buffer, int len); 365 366extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp); 367extern stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 368#ifndef STBI_NO_STDIO 369extern int stbi_psd_test_file (FILE *f); 370extern stbi_uc *stbi_psd_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 371#endif 372 373// is it an hdr? 374extern int stbi_hdr_test_memory (stbi_uc const *buffer, int len); 375 376extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp); 377extern float * stbi_hdr_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 378#ifndef STBI_NO_STDIO 379extern int stbi_hdr_test_file (FILE *f); 380extern float * stbi_hdr_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 381#endif 382 383// is it a pic? 384extern int stbi_pic_test_memory (stbi_uc const *buffer, int len); 385 386extern stbi_uc *stbi_pic_load (char const *filename, int *x, int *y, int *comp, int req_comp); 387extern stbi_uc *stbi_pic_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 388#ifndef STBI_NO_STDIO 389extern int stbi_pic_test_file (FILE *f); 390extern stbi_uc *stbi_pic_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 391#endif 392 393// is it a gif? 394extern int stbi_gif_test_memory (stbi_uc const *buffer, int len); 395 396extern stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp); 397extern stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 398extern int stbi_gif_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); 399 400#ifndef STBI_NO_STDIO 401extern int stbi_gif_test_file (FILE *f); 402extern stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 403extern int stbi_gif_info (char const *filename, int *x, int *y, int *comp); 404extern int stbi_gif_info_from_file (FILE *f, int *x, int *y, int *comp); 405#endif 406 407#endif//STBI_TYPE_SPECIFIC_FUNCTIONS 408 409 410 411 412#ifdef __cplusplus 413} 414#endif 415 416// 417// 418//// end header file ///////////////////////////////////////////////////// 419#endif // STBI_INCLUDE_STB_IMAGE_H 420 421#ifndef STBI_HEADER_FILE_ONLY 422 423#ifndef STBI_NO_HDR 424#include <math.h> // ldexp 425#include <string.h> // strcmp 426#endif 427 428#ifndef STBI_NO_STDIO 429#include <stdio.h> 430#endif 431#ifdef _KERNEL 432#include <sys/cdefs.h> 433__KERNEL_RCSID(0, "$NetBSD: stb_image.c,v 1.10 2021/12/05 07:13:48 msaitoh Exp $"); 434#include <sys/param.h> 435#include <sys/systm.h> 436#include <sys/kernel.h> 437#include <sys/types.h> 438#include <sys/malloc.h> 439#else 440#include <stdlib.h> 441#include <memory.h> 442#include <assert.h> 443#include <stdarg.h> 444#endif 445 446#ifdef _KERNEL 447#define MALLOC(size) malloc((size), M_TEMP, M_WAITOK) 448#define REALLOC(ptr, size) realloc((ptr), (size), M_TEMP, M_WAITOK) 449#define FREE(ptr) \ 450 do { if (ptr) free((ptr), M_TEMP); } while (/*CONSTCOND*/0) 451#else 452#define MALLOC(size) malloc((size)) 453#define REALLOC(ptr, size) realloc((ptr), (size)) 454#define FREE(ptr) free((ptr)) 455#endif 456 457#ifndef _MSC_VER 458 #ifdef __cplusplus 459 #define __forceinline inline 460 #else 461 #define __forceinline 462 #endif 463#endif 464 465 466// implementation: 467typedef unsigned char uint8; 468typedef unsigned short uint16; 469typedef signed short int16; 470typedef unsigned int uint32; 471typedef signed int int32; 472#ifndef __NetBSD__ 473typedef unsigned int uint; 474#endif 475 476// should produce compiler error if size is wrong 477typedef unsigned char validate_uint32[sizeof(uint32)==4 ? 1 : -1]; 478 479#if defined(STBI_NO_STDIO) && !defined(STBI_NO_WRITE) 480#define STBI_NO_WRITE 481#endif 482 483#define STBI_NOTUSED(v) v=v 484 485#ifdef _MSC_VER 486#define STBI_HAS_LRTOL 487#endif 488 489#ifdef STBI_HAS_LRTOL 490 #define stbi_lrot(x,y) _lrotl(x,y) 491#else 492 #define stbi_lrot(x,y) (((x) << (y)) | ((x) >> (32 - (y)))) 493#endif 494 495////////////////////////////////////////////////////////////////////////////// 496// 497// Generic API that works on all image types 498// 499 500// deprecated functions 501 502// is it a jpeg? 503extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len); 504extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 505extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); 506 507#ifndef STBI_NO_STDIO 508extern stbi_uc *stbi_jpeg_load (char const *filename, int *x, int *y, int *comp, int req_comp); 509extern int stbi_jpeg_test_file (FILE *f); 510extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 511 512extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp); 513extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp); 514#endif 515 516// is it a png? 517extern int stbi_png_test_memory (stbi_uc const *buffer, int len); 518extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 519extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); 520 521#ifndef STBI_NO_STDIO 522extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp); 523extern int stbi_png_info (char const *filename, int *x, int *y, int *comp); 524extern int stbi_png_test_file (FILE *f); 525extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 526extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp); 527#endif 528 529// is it a bmp? 530extern int stbi_bmp_test_memory (stbi_uc const *buffer, int len); 531 532extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp); 533extern stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 534#ifndef STBI_NO_STDIO 535extern int stbi_bmp_test_file (FILE *f); 536extern stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 537#endif 538 539// is it a tga? 540extern int stbi_tga_test_memory (stbi_uc const *buffer, int len); 541 542extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp); 543extern stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 544#ifndef STBI_NO_STDIO 545extern int stbi_tga_test_file (FILE *f); 546extern stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 547#endif 548 549// is it a psd? 550extern int stbi_psd_test_memory (stbi_uc const *buffer, int len); 551 552extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp); 553extern stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 554#ifndef STBI_NO_STDIO 555extern int stbi_psd_test_file (FILE *f); 556extern stbi_uc *stbi_psd_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 557#endif 558 559// is it an hdr? 560extern int stbi_hdr_test_memory (stbi_uc const *buffer, int len); 561 562extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp); 563extern float * stbi_hdr_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 564#ifndef STBI_NO_STDIO 565extern int stbi_hdr_test_file (FILE *f); 566extern float * stbi_hdr_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 567#endif 568 569// is it a pic? 570extern int stbi_pic_test_memory (stbi_uc const *buffer, int len); 571 572extern stbi_uc *stbi_pic_load (char const *filename, int *x, int *y, int *comp, int req_comp); 573extern stbi_uc *stbi_pic_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 574#ifndef STBI_NO_STDIO 575extern int stbi_pic_test_file (FILE *f); 576extern stbi_uc *stbi_pic_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 577#endif 578 579// is it a gif? 580extern int stbi_gif_test_memory (stbi_uc const *buffer, int len); 581 582extern stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp); 583extern stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); 584extern int stbi_gif_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); 585 586#ifndef STBI_NO_STDIO 587extern int stbi_gif_test_file (FILE *f); 588extern stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp); 589extern int stbi_gif_info (char const *filename, int *x, int *y, int *comp); 590extern int stbi_gif_info_from_file (FILE *f, int *x, int *y, int *comp); 591#endif 592 593 594// this is not threadsafe 595static const char *failure_reason; 596 597const char *stbi_failure_reason(void) 598{ 599 return failure_reason; 600} 601 602#ifndef STBI_NO_FAILURE_STRINGS 603static int e(const char *str) 604{ 605 failure_reason = str; 606 return 0; 607} 608#endif 609 610#ifdef STBI_NO_FAILURE_STRINGS 611 #define e(x,y) 0 612#elif defined(STBI_FAILURE_USERMSG) 613 #define e(x,y) e(y) 614#else 615 #define e(x,y) e(x) 616#endif 617 618#define epf(x,y) ((float *) (e(x,y)?NULL:NULL)) 619#define epuc(x,y) ((unsigned char *) (e(x,y)?NULL:NULL)) 620 621void stbi_image_free(void *retval_from_stbi_load) 622{ 623 FREE(retval_from_stbi_load); 624} 625 626#define MAX_LOADERS 32 627stbi_loader *loaders[MAX_LOADERS]; 628static int max_loaders = 0; 629 630int stbi_register_loader(stbi_loader *loader) 631{ 632 int i; 633 for (i=0; i < MAX_LOADERS; ++i) { 634 // already present? 635 if (loaders[i] == loader) 636 return 1; 637 // end of the list? 638 if (loaders[i] == NULL) { 639 loaders[i] = loader; 640 max_loaders = i+1; 641 return 1; 642 } 643 } 644 // no room for it 645 return 0; 646} 647 648#ifndef STBI_NO_HDR 649static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp); 650static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp); 651#endif 652 653#ifndef STBI_NO_STDIO 654unsigned char *stbi_load(char const *filename, int *x, int *y, int *comp, int req_comp) 655{ 656 FILE *f = fopen(filename, "rb"); 657 unsigned char *result; 658 if (!f) return epuc("can't fopen", "Unable to open file"); 659 result = stbi_load_from_file(f,x,y,comp,req_comp); 660 fclose(f); 661 return result; 662} 663 664unsigned char *stbi_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 665{ 666 int i; 667 if (stbi_jpeg_test_file(f)) return stbi_jpeg_load_from_file(f,x,y,comp,req_comp); 668 if (stbi_png_test_file(f)) return stbi_png_load_from_file(f,x,y,comp,req_comp); 669 if (stbi_bmp_test_file(f)) return stbi_bmp_load_from_file(f,x,y,comp,req_comp); 670 if (stbi_gif_test_file(f)) return stbi_gif_load_from_file(f,x,y,comp,req_comp); 671 if (stbi_psd_test_file(f)) return stbi_psd_load_from_file(f,x,y,comp,req_comp); 672 if (stbi_pic_test_file(f)) return stbi_pic_load_from_file(f,x,y,comp,req_comp); 673 674 #ifndef STBI_NO_HDR 675 if (stbi_hdr_test_file(f)) { 676 float *hdr = stbi_hdr_load_from_file(f, x,y,comp,req_comp); 677 return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp); 678 } 679 #endif 680 681 for (i=0; i < max_loaders; ++i) 682 if (loaders[i]->test_file(f)) 683 return loaders[i]->load_from_file(f,x,y,comp,req_comp); 684 // test tga last because it's a crappy test! 685 if (stbi_tga_test_file(f)) 686 return stbi_tga_load_from_file(f,x,y,comp,req_comp); 687 return epuc("unknown image type", "Image not of any known type, or corrupt"); 688} 689#endif 690 691unsigned char *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 692{ 693 int i; 694 if (stbi_jpeg_test_memory(buffer,len)) return stbi_jpeg_load_from_memory(buffer,len,x,y,comp,req_comp); 695 if (stbi_png_test_memory(buffer,len)) return stbi_png_load_from_memory(buffer,len,x,y,comp,req_comp); 696 if (stbi_bmp_test_memory(buffer,len)) return stbi_bmp_load_from_memory(buffer,len,x,y,comp,req_comp); 697 if (stbi_gif_test_memory(buffer,len)) return stbi_gif_load_from_memory(buffer,len,x,y,comp,req_comp); 698 if (stbi_psd_test_memory(buffer,len)) return stbi_psd_load_from_memory(buffer,len,x,y,comp,req_comp); 699 if (stbi_pic_test_memory(buffer,len)) return stbi_pic_load_from_memory(buffer,len,x,y,comp,req_comp); 700 701 #ifndef STBI_NO_HDR 702 if (stbi_hdr_test_memory(buffer, len)) { 703 float *hdr = stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp); 704 return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp); 705 } 706 #endif 707 708 for (i=0; i < max_loaders; ++i) 709 if (loaders[i]->test_memory(buffer,len)) 710 return loaders[i]->load_from_memory(buffer,len,x,y,comp,req_comp); 711 // test tga last because it's a crappy test! 712 if (stbi_tga_test_memory(buffer,len)) 713 return stbi_tga_load_from_memory(buffer,len,x,y,comp,req_comp); 714 return epuc("unknown image type", "Image not of any known type, or corrupt"); 715} 716 717#ifndef STBI_NO_HDR 718 719#ifndef STBI_NO_STDIO 720float *stbi_loadf(char const *filename, int *x, int *y, int *comp, int req_comp) 721{ 722 FILE *f = fopen(filename, "rb"); 723 float *result; 724 if (!f) return epf("can't fopen", "Unable to open file"); 725 result = stbi_loadf_from_file(f,x,y,comp,req_comp); 726 fclose(f); 727 return result; 728} 729 730float *stbi_loadf_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 731{ 732 unsigned char *data; 733 #ifndef STBI_NO_HDR 734 if (stbi_hdr_test_file(f)) 735 return stbi_hdr_load_from_file(f,x,y,comp,req_comp); 736 #endif 737 data = stbi_load_from_file(f, x, y, comp, req_comp); 738 if (data) 739 return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp); 740 return epf("unknown image type", "Image not of any known type, or corrupt"); 741} 742#endif 743 744float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 745{ 746 stbi_uc *data; 747 #ifndef STBI_NO_HDR 748 if (stbi_hdr_test_memory(buffer, len)) 749 return stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp); 750 #endif 751 data = stbi_load_from_memory(buffer, len, x, y, comp, req_comp); 752 if (data) 753 return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp); 754 return epf("unknown image type", "Image not of any known type, or corrupt"); 755} 756#endif 757 758// these is-hdr-or-not is defined independent of whether STBI_NO_HDR is 759// defined, for API simplicity; if STBI_NO_HDR is defined, it always 760// reports false! 761 762int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len) 763{ 764 #ifndef STBI_NO_HDR 765 return stbi_hdr_test_memory(buffer, len); 766 #else 767 STBI_NOTUSED(buffer); 768 STBI_NOTUSED(len); 769 return 0; 770 #endif 771} 772 773#ifndef STBI_NO_STDIO 774extern int stbi_is_hdr (char const *filename) 775{ 776 FILE *f = fopen(filename, "rb"); 777 int result=0; 778 if (f) { 779 result = stbi_is_hdr_from_file(f); 780 fclose(f); 781 } 782 return result; 783} 784 785extern int stbi_is_hdr_from_file(FILE *f) 786{ 787 #ifndef STBI_NO_HDR 788 return stbi_hdr_test_file(f); 789 #else 790 return 0; 791 #endif 792} 793 794#endif 795 796#ifndef STBI_NO_HDR 797static float h2l_gamma_i=1.0f/2.2f, h2l_scale_i=1.0f; 798static float l2h_gamma=2.2f, l2h_scale=1.0f; 799 800void stbi_hdr_to_ldr_gamma(float gamma) { h2l_gamma_i = 1/gamma; } 801void stbi_hdr_to_ldr_scale(float scale) { h2l_scale_i = 1/scale; } 802 803void stbi_ldr_to_hdr_gamma(float gamma) { l2h_gamma = gamma; } 804void stbi_ldr_to_hdr_scale(float scale) { l2h_scale = scale; } 805#endif 806 807 808////////////////////////////////////////////////////////////////////////////// 809// 810// Common code used by all image loaders 811// 812 813enum 814{ 815 SCAN_load=0, 816 SCAN_type, 817 SCAN_header 818}; 819 820typedef struct 821{ 822 uint32 img_x, img_y; 823 int img_n, img_out_n; 824 825 #ifndef STBI_NO_STDIO 826 FILE *img_file; 827 int buflen; 828 uint8 buffer_start[128]; 829 int from_file; 830 #endif 831 uint8 const *img_buffer, *img_buffer_end; 832} stbi; 833 834#ifndef STBI_NO_STDIO 835static void start_file(stbi *s, FILE *f) 836{ 837 s->img_file = f; 838 s->buflen = sizeof(s->buffer_start); 839 s->img_buffer_end = s->buffer_start + s->buflen; 840 s->img_buffer = s->img_buffer_end; 841 s->from_file = 1; 842} 843#endif 844 845static void start_mem(stbi *s, uint8 const *buffer, int len) 846{ 847#ifndef STBI_NO_STDIO 848 s->img_file = NULL; 849 s->from_file = 0; 850#endif 851 s->img_buffer = (uint8 const *) buffer; 852 s->img_buffer_end = (uint8 const *) buffer+len; 853} 854 855#ifndef STBI_NO_STDIO 856static void refill_buffer(stbi *s) 857{ 858 int n = fread(s->buffer_start, 1, s->buflen, s->img_file); 859 if (n == 0) { 860 s->from_file = 0; 861 s->img_buffer = s->img_buffer_end-1; 862#if 0 863 *s->img_buffer = 0; 864#endif 865 } else { 866 s->img_buffer = s->buffer_start; 867 s->img_buffer_end = s->buffer_start + n; 868 } 869} 870#endif 871 872__forceinline static int get8(stbi *s) 873{ 874 if (s->img_buffer < s->img_buffer_end) 875 return *s->img_buffer++; 876#ifndef STBI_NO_STDIO 877 if (s->from_file) { 878 refill_buffer(s); 879 return *s->img_buffer++; 880 } 881#endif 882 return 0; 883} 884 885__forceinline static int at_eof(stbi *s) 886{ 887#ifndef STBI_NO_STDIO 888 if (s->img_file) { 889 if (!feof(s->img_file)) return 0; 890 // if feof() is true, check if buffer = end 891 // special case: we've only got the special 0 character at the end 892 if (s->from_file == 0) return 1; 893 } 894#endif 895 return s->img_buffer >= s->img_buffer_end; 896} 897 898__forceinline static uint8 get8u(stbi *s) 899{ 900 return (uint8) get8(s); 901} 902 903static void skip(stbi *s, int n) 904{ 905#ifndef STBI_NO_STDIO 906 if (s->img_file) { 907 int blen = s->img_buffer_end - s->img_buffer; 908 if (blen < n) { 909 s->img_buffer = s->img_buffer_end; 910 fseek(s->img_file, n - blen, SEEK_CUR); 911 return; 912 } 913 } 914#endif 915 s->img_buffer += n; 916} 917 918static int getn(stbi *s, stbi_uc *buffer, int n) 919{ 920#ifndef STBI_NO_STDIO 921 if (s->img_file) { 922 int blen = s->img_buffer_end - s->img_buffer; 923 if (blen < n) { 924 int res; 925 memcpy(buffer, s->img_buffer, blen); 926 res = ((int) fread(buffer + blen, 1, n - blen, s->img_file) == (n-blen)); 927 s->img_buffer = s->img_buffer_end; 928 return res; 929 } 930 } 931#endif 932 if (s->img_buffer+n <= s->img_buffer_end) { 933 memcpy(buffer, s->img_buffer, n); 934 s->img_buffer += n; 935 return 1; 936 } else 937 return 0; 938} 939 940static int get16(stbi *s) 941{ 942 int z = get8(s); 943 return (z << 8) + get8(s); 944} 945 946static uint32 get32(stbi *s) 947{ 948 uint32 z = get16(s); 949 return (z << 16) + get16(s); 950} 951 952static int get16le(stbi *s) 953{ 954 int z = get8(s); 955 return z + (get8(s) << 8); 956} 957 958static uint32 get32le(stbi *s) 959{ 960 uint32 z = get16le(s); 961 return z + (get16le(s) << 16); 962} 963 964////////////////////////////////////////////////////////////////////////////// 965// 966// generic converter from built-in img_n to req_comp 967// individual types do this automatically as much as possible (e.g. jpeg 968// does all cases internally since it needs to colorspace convert anyway, 969// and it never has alpha, so very few cases ). png can automatically 970// interleave an alpha=255 channel, but falls back to this for other cases 971// 972// assume data buffer is malloced, so malloc a new one and free that one 973// only failure mode is malloc failing 974 975static uint8 compute_y(int r, int g, int b) 976{ 977 return (uint8) (((r*77) + (g*150) + (29*b)) >> 8); 978} 979 980static unsigned char *convert_format(unsigned char *data, int img_n, int req_comp, uint x, uint y) 981{ 982 int i,j; 983 unsigned char *good; 984 985 if (req_comp == img_n) return data; 986 assert(req_comp >= 1 && req_comp <= 4); 987 988 good = MALLOC(req_comp * x * y); 989 if (good == NULL) { 990 FREE(data); 991 return epuc("outofmem", "Out of memory"); 992 } 993 994 for (j=0; j < (int) y; ++j) { 995 unsigned char *src = data + j * x * img_n ; 996 unsigned char *dest = good + j * x * req_comp; 997 998 #define COMBO(a,b) ((a)*8+(b)) 999 #define CASE(a,b) case COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b) 1000 // convert source image with img_n components to one with req_comp components; 1001 // avoid switch per pixel, so use switch per scanline and massive macros 1002 switch (COMBO(img_n, req_comp)) { 1003 CASE(1,2) dest[0]=src[0], dest[1]=255; 1004 break; 1005 CASE(1,3) dest[0]=dest[1]=dest[2]=src[0]; 1006 break; 1007 CASE(1,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=255; 1008 break; 1009 CASE(2,1) dest[0]=src[0]; 1010 break; 1011 CASE(2,3) dest[0]=dest[1]=dest[2]=src[0]; 1012 break; 1013 CASE(2,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=src[1]; 1014 break; 1015 CASE(3,4) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2],dest[3]=255; 1016 break; 1017 CASE(3,1) dest[0]=compute_y(src[0],src[1],src[2]); 1018 break; 1019 CASE(3,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = 255; 1020 break; 1021 CASE(4,1) dest[0]=compute_y(src[0],src[1],src[2]); 1022 break; 1023 CASE(4,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = src[3]; 1024 break; 1025 CASE(4,3) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2]; 1026 break; 1027 default: assert(0); 1028 } 1029 #undef CASE 1030 } 1031 1032 FREE(data); 1033 return good; 1034} 1035 1036#ifndef STBI_NO_HDR 1037static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp) 1038{ 1039 int i,k,n; 1040 float *output = MALLOC(x * y * comp * sizeof(float)); 1041 if (output == NULL) { FREE(data); return epf("outofmem", "Out of memory"); } 1042 // compute number of non-alpha components 1043 if (comp & 1) n = comp; else n = comp-1; 1044 for (i=0; i < x*y; ++i) { 1045 for (k=0; k < n; ++k) { 1046 output[i*comp + k] = (float) pow(data[i*comp+k]/255.0f, l2h_gamma) * l2h_scale; 1047 } 1048 if (k < comp) output[i*comp + k] = data[i*comp+k]/255.0f; 1049 } 1050 FREE(data); 1051 return output; 1052} 1053 1054#define float2int(x) ((int) (x)) 1055static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp) 1056{ 1057 int i,k,n; 1058 stbi_uc *output = MALLOC(x * y * comp); 1059 if (output == NULL) { FREE(data); return epuc("outofmem", "Out of memory"); } 1060 // compute number of non-alpha components 1061 if (comp & 1) n = comp; else n = comp-1; 1062 for (i=0; i < x*y; ++i) { 1063 for (k=0; k < n; ++k) { 1064 float z = (float) pow(data[i*comp+k]*h2l_scale_i, h2l_gamma_i) * 255 + 0.5f; 1065 if (z < 0) z = 0; 1066 if (z > 255) z = 255; 1067 output[i*comp + k] = (uint8) float2int(z); 1068 } 1069 if (k < comp) { 1070 float z = data[i*comp+k] * 255 + 0.5f; 1071 if (z < 0) z = 0; 1072 if (z > 255) z = 255; 1073 output[i*comp + k] = (uint8) float2int(z); 1074 } 1075 } 1076 FREE(data); 1077 return output; 1078} 1079#endif 1080 1081////////////////////////////////////////////////////////////////////////////// 1082// 1083// "baseline" JPEG/JFIF decoder (not actually fully baseline implementation) 1084// 1085// simple implementation 1086// - channel subsampling of at most 2 in each dimension 1087// - doesn't support delayed output of y-dimension 1088// - simple interface (only one output format: 8-bit interleaved RGB) 1089// - doesn't try to recover corrupt jpegs 1090// - doesn't allow partial loading, loading multiple at once 1091// - still fast on x86 (copying globals into locals doesn't help x86) 1092// - allocates lots of intermediate memory (full size of all components) 1093// - non-interleaved case requires this anyway 1094// - allows good upsampling (see next) 1095// high-quality 1096// - upsampled channels are bilinearly interpolated, even across blocks 1097// - quality integer IDCT derived from IJG's 'slow' 1098// performance 1099// - fast huffman; reasonable integer IDCT 1100// - uses a lot of intermediate memory, could cache poorly 1101// - load http://nothings.org/remote/anemones.jpg 3 times on 2.8Ghz P4 1102// stb_jpeg: 1.34 seconds (MSVC6, default release build) 1103// stb_jpeg: 1.06 seconds (MSVC6, processor = Pentium Pro) 1104// IJL11.dll: 1.08 seconds (compiled by intel) 1105// IJG 1998: 0.98 seconds (MSVC6, makefile provided by IJG) 1106// IJG 1998: 0.95 seconds (MSVC6, makefile + proc=PPro) 1107 1108// huffman decoding acceleration 1109#define FAST_BITS 9 // larger handles more cases; smaller stomps less cache 1110 1111typedef struct 1112{ 1113 uint8 fast[1 << FAST_BITS]; 1114 // weirdly, repacking this into AoS is a 10% speed loss, instead of a win 1115 uint16 code[256]; 1116 uint8 values[256]; 1117 uint8 size[257]; 1118 unsigned int maxcode[18]; 1119 int delta[17]; // old 'firstsymbol' - old 'firstcode' 1120} huffman; 1121 1122typedef struct 1123{ 1124 #ifdef STBI_SIMD 1125 unsigned short dequant2[4][64]; 1126 #endif 1127 stbi s; 1128 huffman huff_dc[4]; 1129 huffman huff_ac[4]; 1130 uint8 dequant[4][64]; 1131 1132// sizes for components, interleaved MCUs 1133 int img_h_max, img_v_max; 1134 int img_mcu_x, img_mcu_y; 1135 int img_mcu_w, img_mcu_h; 1136 1137// definition of jpeg image component 1138 struct 1139 { 1140 int id; 1141 int h,v; 1142 int tq; 1143 int hd,ha; 1144 int dc_pred; 1145 1146 int x,y,w2,h2; 1147 uint8 *data; 1148 void *raw_data; 1149 uint8 *linebuf; 1150 } img_comp[4]; 1151 1152 uint32 code_buffer; // jpeg entropy-coded buffer 1153 int code_bits; // number of valid bits 1154 unsigned char marker; // marker seen while filling entropy buffer 1155 int nomore; // flag if we saw a marker so must stop 1156 1157 int scan_n, order[4]; 1158 int restart_interval, todo; 1159} jpeg; 1160 1161static int build_huffman(huffman *h, int *count) 1162{ 1163 int i,j,k=0,code; 1164 // build size list for each symbol (from JPEG spec) 1165 for (i=0; i < 16; ++i) 1166 for (j=0; j < count[i]; ++j) 1167 h->size[k++] = (uint8) (i+1); 1168 h->size[k] = 0; 1169 1170 // compute actual symbols (from jpeg spec) 1171 code = 0; 1172 k = 0; 1173 for(j=1; j <= 16; ++j) { 1174 // compute delta to add to code to compute symbol id 1175 h->delta[j] = k - code; 1176 if (h->size[k] == j) { 1177 while (h->size[k] == j) 1178 h->code[k++] = (uint16) (code++); 1179 if (code-1 >= (1 << j)) return e("bad code lengths","Corrupt JPEG"); 1180 } 1181 // compute largest code + 1 for this size, preshifted as needed later 1182 h->maxcode[j] = code << (16-j); 1183 code <<= 1; 1184 } 1185 h->maxcode[j] = 0xffffffff; 1186 1187 // build non-spec acceleration table; 255 is flag for not-accelerated 1188 memset(h->fast, 255, 1 << FAST_BITS); 1189 for (i=0; i < k; ++i) { 1190 int s = h->size[i]; 1191 if (s <= FAST_BITS) { 1192 int c = h->code[i] << (FAST_BITS-s); 1193 int m = 1 << (FAST_BITS-s); 1194 for (j=0; j < m; ++j) { 1195 h->fast[c+j] = (uint8) i; 1196 } 1197 } 1198 } 1199 return 1; 1200} 1201 1202static void grow_buffer_unsafe(jpeg *j) 1203{ 1204 do { 1205 int b = j->nomore ? 0 : get8(&j->s); 1206 if (b == 0xff) { 1207 int c = get8(&j->s); 1208 if (c != 0) { 1209 j->marker = (unsigned char) c; 1210 j->nomore = 1; 1211 return; 1212 } 1213 } 1214 j->code_buffer |= b << (24 - j->code_bits); 1215 j->code_bits += 8; 1216 } while (j->code_bits <= 24); 1217} 1218 1219// (1 << n) - 1 1220static uint32 bmask[17]={0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535}; 1221 1222// decode a jpeg huffman value from the bitstream 1223__forceinline static int decode(jpeg *j, huffman *h) 1224{ 1225 unsigned int temp; 1226 int c,k; 1227 1228 if (j->code_bits < 16) grow_buffer_unsafe(j); 1229 1230 // look at the top FAST_BITS and determine what symbol ID it is, 1231 // if the code is <= FAST_BITS 1232 c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS)-1); 1233 k = h->fast[c]; 1234 if (k < 255) { 1235 int s = h->size[k]; 1236 if (s > j->code_bits) 1237 return -1; 1238 j->code_buffer <<= s; 1239 j->code_bits -= s; 1240 return h->values[k]; 1241 } 1242 1243 // naive test is to shift the code_buffer down so k bits are 1244 // valid, then test against maxcode. To speed this up, we've 1245 // preshifted maxcode left so that it has (16-k) 0s at the 1246 // end; in other words, regardless of the number of bits, it 1247 // wants to be compared against something shifted to have 16; 1248 // that way we don't need to shift inside the loop. 1249 temp = j->code_buffer >> 16; 1250 for (k=FAST_BITS+1 ; ; ++k) 1251 if (temp < h->maxcode[k]) 1252 break; 1253 if (k == 17) { 1254 // error! code not found 1255 j->code_bits -= 16; 1256 return -1; 1257 } 1258 1259 if (k > j->code_bits) 1260 return -1; 1261 1262 // convert the huffman code to the symbol id 1263 c = ((j->code_buffer >> (32 - k)) & bmask[k]) + h->delta[k]; 1264 assert((((j->code_buffer) >> (32 - h->size[c])) & bmask[h->size[c]]) == h->code[c]); 1265 1266 // convert the id to a symbol 1267 j->code_bits -= k; 1268 j->code_buffer <<= k; 1269 return h->values[c]; 1270} 1271 1272// combined JPEG 'receive' and JPEG 'extend', since baseline 1273// always extends everything it receives. 1274__forceinline static int extend_receive(jpeg *j, int n) 1275{ 1276 unsigned int m = 1 << (n-1); 1277 unsigned int k; 1278 if (j->code_bits < n) grow_buffer_unsafe(j); 1279 1280 #if 1 1281 k = stbi_lrot(j->code_buffer, n); 1282 j->code_buffer = k & ~bmask[n]; 1283 k &= bmask[n]; 1284 j->code_bits -= n; 1285 #else 1286 k = (j->code_buffer >> (32 - n)) & bmask[n]; 1287 j->code_bits -= n; 1288 j->code_buffer <<= n; 1289 #endif 1290 // the following test is probably a random branch that won't 1291 // predict well. I tried to table accelerate it but failed. 1292 // maybe it's compiling as a conditional move? 1293 if (k < m) 1294 return (UINT_MAX << n) + k + 1; 1295 else 1296 return k; 1297} 1298 1299// given a value that's at position X in the zigzag stream, 1300// where does it appear in the 8x8 matrix coded as row-major? 1301static uint8 dezigzag[64+15] = 1302{ 1303 0, 1, 8, 16, 9, 2, 3, 10, 1304 17, 24, 32, 25, 18, 11, 4, 5, 1305 12, 19, 26, 33, 40, 48, 41, 34, 1306 27, 20, 13, 6, 7, 14, 21, 28, 1307 35, 42, 49, 56, 57, 50, 43, 36, 1308 29, 22, 15, 23, 30, 37, 44, 51, 1309 58, 59, 52, 45, 38, 31, 39, 46, 1310 53, 60, 61, 54, 47, 55, 62, 63, 1311 // let corrupt input sample past end 1312 63, 63, 63, 63, 63, 63, 63, 63, 1313 63, 63, 63, 63, 63, 63, 63 1314}; 1315 1316// decode one 64-entry block-- 1317static int decode_block(jpeg *j, short data[64], huffman *hdc, huffman *hac, int b) 1318{ 1319 int diff,dc,k; 1320 int t = decode(j, hdc); 1321 if (t < 0) return e("bad huffman code","Corrupt JPEG"); 1322 1323 // 0 all the ac values now so we can do it 32-bits at a time 1324 memset(data,0,64*sizeof(data[0])); 1325 1326 diff = t ? extend_receive(j, t) : 0; 1327 dc = j->img_comp[b].dc_pred + diff; 1328 j->img_comp[b].dc_pred = dc; 1329 data[0] = (short) dc; 1330 1331 // decode AC components, see JPEG spec 1332 k = 1; 1333 do { 1334 int r,s; 1335 int rs = decode(j, hac); 1336 if (rs < 0) return e("bad huffman code","Corrupt JPEG"); 1337 s = rs & 15; 1338 r = rs >> 4; 1339 if (s == 0) { 1340 if (rs != 0xf0) break; // end block 1341 k += 16; 1342 } else { 1343 k += r; 1344 // decode into unzigzag'd location 1345 data[dezigzag[k++]] = (short) extend_receive(j,s); 1346 } 1347 } while (k < 64); 1348 return 1; 1349} 1350 1351// take a -128..127 value and clamp it and convert to 0..255 1352__forceinline static uint8 clamp(int x) 1353{ 1354 // trick to use a single test to catch both cases 1355 if ((unsigned int) x > 255) { 1356 if (x < 0) return 0; 1357 if (x > 255) return 255; 1358 } 1359 return (uint8) x; 1360} 1361 1362#define f2f(x) (int) (((x) * 4096 + 0.5)) 1363#define fsh(x) ((x) << 12) 1364 1365// derived from jidctint -- DCT_ISLOW 1366#define IDCT_1D(s0,s1,s2,s3,s4,s5,s6,s7) \ 1367 int t0,t1,t2,t3,p1,p2,p3,p4,p5,x0,x1,x2,x3; \ 1368 p2 = s2; \ 1369 p3 = s6; \ 1370 p1 = (p2+p3) * f2f(0.5411961f); \ 1371 t2 = p1 + p3*f2f(-1.847759065f); \ 1372 t3 = p1 + p2*f2f( 0.765366865f); \ 1373 p2 = s0; \ 1374 p3 = s4; \ 1375 t0 = fsh(p2+p3); \ 1376 t1 = fsh(p2-p3); \ 1377 x0 = t0+t3; \ 1378 x3 = t0-t3; \ 1379 x1 = t1+t2; \ 1380 x2 = t1-t2; \ 1381 t0 = s7; \ 1382 t1 = s5; \ 1383 t2 = s3; \ 1384 t3 = s1; \ 1385 p3 = t0+t2; \ 1386 p4 = t1+t3; \ 1387 p1 = t0+t3; \ 1388 p2 = t1+t2; \ 1389 p5 = (p3+p4)*f2f( 1.175875602f); \ 1390 t0 = t0*f2f( 0.298631336f); \ 1391 t1 = t1*f2f( 2.053119869f); \ 1392 t2 = t2*f2f( 3.072711026f); \ 1393 t3 = t3*f2f( 1.501321110f); \ 1394 p1 = p5 + p1*f2f(-0.899976223f); \ 1395 p2 = p5 + p2*f2f(-2.562915447f); \ 1396 p3 = p3*f2f(-1.961570560f); \ 1397 p4 = p4*f2f(-0.390180644f); \ 1398 t3 += p1+p4; \ 1399 t2 += p2+p3; \ 1400 t1 += p2+p4; \ 1401 t0 += p1+p3; 1402 1403#ifdef STBI_SIMD 1404typedef unsigned short stbi_dequantize_t; 1405#else 1406typedef uint8 stbi_dequantize_t; 1407#endif 1408 1409// .344 seconds on 3*anemones.jpg 1410static void idct_block(uint8 *out, int out_stride, short data[64], stbi_dequantize_t *dequantize) 1411{ 1412 int i,val[64],*v=val; 1413 stbi_dequantize_t *dq = dequantize; 1414 uint8 *o; 1415 short *d = data; 1416 1417 // columns 1418 for (i=0; i < 8; ++i,++d,++dq, ++v) { 1419 // if all zeroes, shortcut -- this avoids dequantizing 0s and IDCTing 1420 if (d[ 8]==0 && d[16]==0 && d[24]==0 && d[32]==0 1421 && d[40]==0 && d[48]==0 && d[56]==0) { 1422 // no shortcut 0 seconds 1423 // (1|2|3|4|5|6|7)==0 0 seconds 1424 // all separate -0.047 seconds 1425 // 1 && 2|3 && 4|5 && 6|7: -0.047 seconds 1426 int dcterm = d[0] * dq[0] << 2; 1427 v[0] = v[8] = v[16] = v[24] = v[32] = v[40] = v[48] = v[56] = dcterm; 1428 } else { 1429 IDCT_1D(d[ 0]*dq[ 0],d[ 8]*dq[ 8],d[16]*dq[16],d[24]*dq[24], 1430 d[32]*dq[32],d[40]*dq[40],d[48]*dq[48],d[56]*dq[56]) 1431 // constants scaled things up by 1<<12; let's bring them back 1432 // down, but keep 2 extra bits of precision 1433 x0 += 512; x1 += 512; x2 += 512; x3 += 512; 1434 v[ 0] = (x0+t3) >> 10; 1435 v[56] = (x0-t3) >> 10; 1436 v[ 8] = (x1+t2) >> 10; 1437 v[48] = (x1-t2) >> 10; 1438 v[16] = (x2+t1) >> 10; 1439 v[40] = (x2-t1) >> 10; 1440 v[24] = (x3+t0) >> 10; 1441 v[32] = (x3-t0) >> 10; 1442 } 1443 } 1444 1445 for (i=0, v=val, o=out; i < 8; ++i,v+=8,o+=out_stride) { 1446 // no fast case since the first 1D IDCT spread components out 1447 IDCT_1D(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7]) 1448 // constants scaled things up by 1<<12, plus we had 1<<2 from first 1449 // loop, plus horizontal and vertical each scale by sqrt(8) so together 1450 // we've got an extra 1<<3, so 1<<17 total we need to remove. 1451 // so we want to round that, which means adding 0.5 * 1<<17, 1452 // aka 65536. Also, we'll end up with -128 to 127 that we want 1453 // to encode as 0..255 by adding 128, so we'll add that before the shift 1454 x0 += 65536 + (128<<17); 1455 x1 += 65536 + (128<<17); 1456 x2 += 65536 + (128<<17); 1457 x3 += 65536 + (128<<17); 1458 // tried computing the shifts into temps, or'ing the temps to see 1459 // if any were out of range, but that was slower 1460 o[0] = clamp((x0+t3) >> 17); 1461 o[7] = clamp((x0-t3) >> 17); 1462 o[1] = clamp((x1+t2) >> 17); 1463 o[6] = clamp((x1-t2) >> 17); 1464 o[2] = clamp((x2+t1) >> 17); 1465 o[5] = clamp((x2-t1) >> 17); 1466 o[3] = clamp((x3+t0) >> 17); 1467 o[4] = clamp((x3-t0) >> 17); 1468 } 1469} 1470 1471#ifdef STBI_SIMD 1472static stbi_idct_8x8 stbi_idct_installed = idct_block; 1473 1474extern void stbi_install_idct(stbi_idct_8x8 func) 1475{ 1476 stbi_idct_installed = func; 1477} 1478#endif 1479 1480#define MARKER_none 0xff 1481// if there's a pending marker from the entropy stream, return that 1482// otherwise, fetch from the stream and get a marker. if there's no 1483// marker, return 0xff, which is never a valid marker value 1484static uint8 get_marker(jpeg *j) 1485{ 1486 uint8 x; 1487 if (j->marker != MARKER_none) { x = j->marker; j->marker = MARKER_none; return x; } 1488 x = get8u(&j->s); 1489 if (x != 0xff) return MARKER_none; 1490 while (x == 0xff) 1491 x = get8u(&j->s); 1492 return x; 1493} 1494 1495// in each scan, we'll have scan_n components, and the order 1496// of the components is specified by order[] 1497#define RESTART(x) ((x) >= 0xd0 && (x) <= 0xd7) 1498 1499// after a restart interval, reset the entropy decoder and 1500// the dc prediction 1501static void reset(jpeg *j) 1502{ 1503 j->code_bits = 0; 1504 j->code_buffer = 0; 1505 j->nomore = 0; 1506 j->img_comp[0].dc_pred = j->img_comp[1].dc_pred = j->img_comp[2].dc_pred = 0; 1507 j->marker = MARKER_none; 1508 j->todo = j->restart_interval ? j->restart_interval : 0x7fffffff; 1509 // no more than 1<<31 MCUs if no restart_interal? that's plenty safe, 1510 // since we don't even allow 1<<30 pixels 1511} 1512 1513static int parse_entropy_coded_data(jpeg *z) 1514{ 1515 reset(z); 1516 if (z->scan_n == 1) { 1517 int i,j; 1518 #ifdef STBI_SIMD 1519 __declspec(align(16)) 1520 #endif 1521 short data[64]; 1522 int n = z->order[0]; 1523 // non-interleaved data, we just need to process one block at a time, 1524 // in trivial scanline order 1525 // number of blocks to do just depends on how many actual "pixels" this 1526 // component has, independent of interleaved MCU blocking and such 1527 int w = (z->img_comp[n].x+7) >> 3; 1528 int h = (z->img_comp[n].y+7) >> 3; 1529 for (j=0; j < h; ++j) { 1530 for (i=0; i < w; ++i) { 1531 if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0; 1532 #ifdef STBI_SIMD 1533 stbi_idct_installed(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data, z->dequant2[z->img_comp[n].tq]); 1534 #else 1535 idct_block(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data, z->dequant[z->img_comp[n].tq]); 1536 #endif 1537 // every data block is an MCU, so countdown the restart interval 1538 if (--z->todo <= 0) { 1539 if (z->code_bits < 24) grow_buffer_unsafe(z); 1540 // if it's NOT a restart, then just bail, so we get corrupt data 1541 // rather than no data 1542 if (!RESTART(z->marker)) return 1; 1543 reset(z); 1544 } 1545 } 1546 } 1547 } else { // interleaved! 1548 int i,j,k,x,y; 1549 short data[64]; 1550 for (j=0; j < z->img_mcu_y; ++j) { 1551 for (i=0; i < z->img_mcu_x; ++i) { 1552 // scan an interleaved mcu... process scan_n components in order 1553 for (k=0; k < z->scan_n; ++k) { 1554 int n = z->order[k]; 1555 // scan out an mcu's worth of this component; that's just determined 1556 // by the basic H and V specified for the component 1557 for (y=0; y < z->img_comp[n].v; ++y) { 1558 for (x=0; x < z->img_comp[n].h; ++x) { 1559 int x2 = (i*z->img_comp[n].h + x)*8; 1560 int y2 = (j*z->img_comp[n].v + y)*8; 1561 if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0; 1562 #ifdef STBI_SIMD 1563 stbi_idct_installed(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data, z->dequant2[z->img_comp[n].tq]); 1564 #else 1565 idct_block(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data, z->dequant[z->img_comp[n].tq]); 1566 #endif 1567 } 1568 } 1569 } 1570 // after all interleaved components, that's an interleaved MCU, 1571 // so now count down the restart interval 1572 if (--z->todo <= 0) { 1573 if (z->code_bits < 24) grow_buffer_unsafe(z); 1574 // if it's NOT a restart, then just bail, so we get corrupt data 1575 // rather than no data 1576 if (!RESTART(z->marker)) return 1; 1577 reset(z); 1578 } 1579 } 1580 } 1581 } 1582 return 1; 1583} 1584 1585static int process_marker(jpeg *z, int marker) 1586{ 1587 int L; 1588 switch (marker) { 1589 case MARKER_none: // no marker found 1590 return e("expected marker","Corrupt JPEG"); 1591 1592 case 0xC2: // SOF - progressive 1593 return e("progressive jpeg","JPEG format not supported (progressive)"); 1594 1595 case 0xDD: // DRI - specify restart interval 1596 if (get16(&z->s) != 4) return e("bad DRI len","Corrupt JPEG"); 1597 z->restart_interval = get16(&z->s); 1598 return 1; 1599 1600 case 0xDB: // DQT - define quantization table 1601 L = get16(&z->s)-2; 1602 while (L > 0) { 1603 int q = get8(&z->s); 1604 int p = q >> 4; 1605 int t = q & 15,i; 1606 if (p != 0) return e("bad DQT type","Corrupt JPEG"); 1607 if (t > 3) return e("bad DQT table","Corrupt JPEG"); 1608 for (i=0; i < 64; ++i) 1609 z->dequant[t][dezigzag[i]] = get8u(&z->s); 1610 #ifdef STBI_SIMD 1611 for (i=0; i < 64; ++i) 1612 z->dequant2[t][i] = z->dequant[t][i]; 1613 #endif 1614 L -= 65; 1615 } 1616 return L==0; 1617 1618 case 0xC4: // DHT - define huffman table 1619 L = get16(&z->s)-2; 1620 while (L > 0) { 1621 uint8 *v; 1622 int sizes[16],i,m=0; 1623 int q = get8(&z->s); 1624 int tc = q >> 4; 1625 int th = q & 15; 1626 if (tc > 1 || th > 3) return e("bad DHT header","Corrupt JPEG"); 1627 for (i=0; i < 16; ++i) { 1628 sizes[i] = get8(&z->s); 1629 m += sizes[i]; 1630 } 1631 L -= 17; 1632 if (tc == 0) { 1633 if (!build_huffman(z->huff_dc+th, sizes)) return 0; 1634 v = z->huff_dc[th].values; 1635 } else { 1636 if (!build_huffman(z->huff_ac+th, sizes)) return 0; 1637 v = z->huff_ac[th].values; 1638 } 1639 for (i=0; i < m; ++i) 1640 v[i] = get8u(&z->s); 1641 L -= m; 1642 } 1643 return L==0; 1644 } 1645 // check for comment block or APP blocks 1646 if ((marker >= 0xE0 && marker <= 0xEF) || marker == 0xFE) { 1647 skip(&z->s, get16(&z->s)-2); 1648 return 1; 1649 } 1650 return 0; 1651} 1652 1653// after we see SOS 1654static int process_scan_header(jpeg *z) 1655{ 1656 int i; 1657 int Ls = get16(&z->s); 1658 z->scan_n = get8(&z->s); 1659 if (z->scan_n < 1 || z->scan_n > 4 || z->scan_n > (int) z->s.img_n) return e("bad SOS component count","Corrupt JPEG"); 1660 if (Ls != 6+2*z->scan_n) return e("bad SOS len","Corrupt JPEG"); 1661 for (i=0; i < z->scan_n; ++i) { 1662 int id = get8(&z->s), which; 1663 int q = get8(&z->s); 1664 for (which = 0; which < z->s.img_n; ++which) 1665 if (z->img_comp[which].id == id) 1666 break; 1667 if (which == z->s.img_n) return 0; 1668 z->img_comp[which].hd = q >> 4; if (z->img_comp[which].hd > 3) return e("bad DC huff","Corrupt JPEG"); 1669 z->img_comp[which].ha = q & 15; if (z->img_comp[which].ha > 3) return e("bad AC huff","Corrupt JPEG"); 1670 z->order[i] = which; 1671 } 1672 if (get8(&z->s) != 0) return e("bad SOS","Corrupt JPEG"); 1673 get8(&z->s); // should be 63, but might be 0 1674 if (get8(&z->s) != 0) return e("bad SOS","Corrupt JPEG"); 1675 1676 return 1; 1677} 1678 1679static int process_frame_header(jpeg *z, int scan) 1680{ 1681 stbi *s = &z->s; 1682 int Lf,p,i,q, h_max=1,v_max=1,c; 1683 Lf = get16(s); if (Lf < 11) return e("bad SOF len","Corrupt JPEG"); // JPEG 1684 p = get8(s); if (p != 8) return e("only 8-bit","JPEG format not supported: 8-bit only"); // JPEG baseline 1685 s->img_y = get16(s); if (s->img_y == 0) return e("no header height", "JPEG format not supported: delayed height"); // Legal, but we don't handle it--but neither does IJG 1686 s->img_x = get16(s); if (s->img_x == 0) return e("0 width","Corrupt JPEG"); // JPEG requires 1687 c = get8(s); 1688 if (c != 3 && c != 1) return e("bad component count","Corrupt JPEG"); // JFIF requires 1689 s->img_n = c; 1690 for (i=0; i < c; ++i) { 1691 z->img_comp[i].data = NULL; 1692 z->img_comp[i].linebuf = NULL; 1693 } 1694 1695 if (Lf != 8+3*s->img_n) return e("bad SOF len","Corrupt JPEG"); 1696 1697 for (i=0; i < s->img_n; ++i) { 1698 z->img_comp[i].id = get8(s); 1699 if (z->img_comp[i].id != i+1) // JFIF requires 1700 if (z->img_comp[i].id != i) // some version of jpegtran outputs non-JFIF-compliant files! 1701 return e("bad component ID","Corrupt JPEG"); 1702 q = get8(s); 1703 z->img_comp[i].h = (q >> 4); if (!z->img_comp[i].h || z->img_comp[i].h > 4) return e("bad H","Corrupt JPEG"); 1704 z->img_comp[i].v = q & 15; if (!z->img_comp[i].v || z->img_comp[i].v > 4) return e("bad V","Corrupt JPEG"); 1705 z->img_comp[i].tq = get8(s); if (z->img_comp[i].tq > 3) return e("bad TQ","Corrupt JPEG"); 1706 } 1707 1708 if (scan != SCAN_load) return 1; 1709 1710 if ((1 << 30) / s->img_x / s->img_n < s->img_y) return e("too large", "Image too large to decode"); 1711 1712 for (i=0; i < s->img_n; ++i) { 1713 if (z->img_comp[i].h > h_max) h_max = z->img_comp[i].h; 1714 if (z->img_comp[i].v > v_max) v_max = z->img_comp[i].v; 1715 } 1716 1717 // compute interleaved mcu info 1718 z->img_h_max = h_max; 1719 z->img_v_max = v_max; 1720 z->img_mcu_w = h_max * 8; 1721 z->img_mcu_h = v_max * 8; 1722 z->img_mcu_x = (s->img_x + z->img_mcu_w-1) / z->img_mcu_w; 1723 z->img_mcu_y = (s->img_y + z->img_mcu_h-1) / z->img_mcu_h; 1724 1725 for (i=0; i < s->img_n; ++i) { 1726 // number of effective pixels (e.g. for non-interleaved MCU) 1727 z->img_comp[i].x = (s->img_x * z->img_comp[i].h + h_max-1) / h_max; 1728 z->img_comp[i].y = (s->img_y * z->img_comp[i].v + v_max-1) / v_max; 1729 // to simplify generation, we'll allocate enough memory to decode 1730 // the bogus oversized data from using interleaved MCUs and their 1731 // big blocks (e.g. a 16x16 iMCU on an image of width 33); we won't 1732 // discard the extra data until colorspace conversion 1733 z->img_comp[i].w2 = z->img_mcu_x * z->img_comp[i].h * 8; 1734 z->img_comp[i].h2 = z->img_mcu_y * z->img_comp[i].v * 8; 1735 z->img_comp[i].raw_data = MALLOC(z->img_comp[i].w2 * z->img_comp[i].h2+15); 1736 if (z->img_comp[i].raw_data == NULL) { 1737 for(--i; i >= 0; --i) { 1738 FREE(z->img_comp[i].raw_data); 1739 z->img_comp[i].data = NULL; 1740 } 1741 return e("outofmem", "Out of memory"); 1742 } 1743 // align blocks for installable-idct using mmx/sse 1744 z->img_comp[i].data = (uint8*) (((size_t) z->img_comp[i].raw_data + 15) & ~15); 1745 z->img_comp[i].linebuf = NULL; 1746 } 1747 1748 return 1; 1749} 1750 1751// use comparisons since in some cases we handle more than one case (e.g. SOF) 1752#define DNL(x) ((x) == 0xdc) 1753#define SOI(x) ((x) == 0xd8) 1754#define EOI(x) ((x) == 0xd9) 1755#define SOF(x) ((x) == 0xc0 || (x) == 0xc1) 1756#define SOS(x) ((x) == 0xda) 1757 1758static int decode_jpeg_header(jpeg *z, int scan) 1759{ 1760 int m; 1761 z->marker = MARKER_none; // initialize cached marker to empty 1762 m = get_marker(z); 1763 if (!SOI(m)) return e("no SOI","Corrupt JPEG"); 1764 if (scan == SCAN_type) return 1; 1765 m = get_marker(z); 1766 while (!SOF(m)) { 1767 if (!process_marker(z,m)) return 0; 1768 m = get_marker(z); 1769 while (m == MARKER_none) { 1770 // some files have extra padding after their blocks, so ok, we'll scan 1771 if (at_eof(&z->s)) return e("no SOF", "Corrupt JPEG"); 1772 m = get_marker(z); 1773 } 1774 } 1775 if (!process_frame_header(z, scan)) return 0; 1776 return 1; 1777} 1778 1779static int decode_jpeg_image(jpeg *j) 1780{ 1781 int m; 1782 j->restart_interval = 0; 1783 if (!decode_jpeg_header(j, SCAN_load)) return 0; 1784 m = get_marker(j); 1785 while (!EOI(m)) { 1786 if (SOS(m)) { 1787 if (!process_scan_header(j)) return 0; 1788 if (!parse_entropy_coded_data(j)) return 0; 1789 if (j->marker == MARKER_none ) { 1790 // handle 0s at the end of image data from IP Kamera 9060 1791 while (!at_eof(&j->s)) { 1792 int x = get8(&j->s); 1793 if (x == 255) { 1794 j->marker = get8u(&j->s); 1795 break; 1796 } else if (x != 0) { 1797 return 0; 1798 } 1799 } 1800 // if we reach eof without hitting a marker, get_marker() below will fail and we'll eventually return 0 1801 } 1802 } else { 1803 if (!process_marker(j, m)) return 0; 1804 } 1805 m = get_marker(j); 1806 } 1807 return 1; 1808} 1809 1810// static jfif-centered resampling (across block boundaries) 1811 1812typedef uint8 *(*resample_row_func)(uint8 *out, uint8 *in0, uint8 *in1, 1813 int w, int hs); 1814 1815#define div4(x) ((uint8) ((x) >> 2)) 1816 1817static uint8 *resample_row_1(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) 1818{ 1819 STBI_NOTUSED(out); 1820 STBI_NOTUSED(in_far); 1821 STBI_NOTUSED(w); 1822 STBI_NOTUSED(hs); 1823 return in_near; 1824} 1825 1826static uint8* resample_row_v_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) 1827{ 1828 // need to generate two samples vertically for every one in input 1829 int i; 1830 STBI_NOTUSED(hs); 1831 for (i=0; i < w; ++i) 1832 out[i] = div4(3*in_near[i] + in_far[i] + 2); 1833 return out; 1834} 1835 1836static uint8* resample_row_h_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) 1837{ 1838 // need to generate two samples horizontally for every one in input 1839 int i; 1840 uint8 *input = in_near; 1841 1842 if (w == 1) { 1843 // if only one sample, can't do any interpolation 1844 out[0] = out[1] = input[0]; 1845 return out; 1846 } 1847 1848 out[0] = input[0]; 1849 out[1] = div4(input[0]*3 + input[1] + 2); 1850 for (i=1; i < w-1; ++i) { 1851 int n = 3*input[i]+2; 1852 out[i*2+0] = div4(n+input[i-1]); 1853 out[i*2+1] = div4(n+input[i+1]); 1854 } 1855 out[i*2+0] = div4(input[w-2]*3 + input[w-1] + 2); 1856 out[i*2+1] = input[w-1]; 1857 1858 STBI_NOTUSED(in_far); 1859 STBI_NOTUSED(hs); 1860 1861 return out; 1862} 1863 1864#define div16(x) ((uint8) ((x) >> 4)) 1865 1866static uint8 *resample_row_hv_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) 1867{ 1868 // need to generate 2x2 samples for every one in input 1869 int i,t0,t1; 1870 if (w == 1) { 1871 out[0] = out[1] = div4(3*in_near[0] + in_far[0] + 2); 1872 return out; 1873 } 1874 1875 t1 = 3*in_near[0] + in_far[0]; 1876 out[0] = div4(t1+2); 1877 for (i=1; i < w; ++i) { 1878 t0 = t1; 1879 t1 = 3*in_near[i]+in_far[i]; 1880 out[i*2-1] = div16(3*t0 + t1 + 8); 1881 out[i*2 ] = div16(3*t1 + t0 + 8); 1882 } 1883 out[w*2-1] = div4(t1+2); 1884 1885 STBI_NOTUSED(hs); 1886 1887 return out; 1888} 1889 1890static uint8 *resample_row_generic(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) 1891{ 1892 // resample with nearest-neighbor 1893 int i,j; 1894 in_far = in_far; 1895 for (i=0; i < w; ++i) 1896 for (j=0; j < hs; ++j) 1897 out[i*hs+j] = in_near[i]; 1898 return out; 1899} 1900 1901#define float2fixed(x) ((int) ((x) * 65536 + 0.5)) 1902 1903// 0.38 seconds on 3*anemones.jpg (0.25 with processor = Pro) 1904// VC6 without processor=Pro is generating multiple LEAs per multiply! 1905static void YCbCr_to_RGB_row(uint8 *out, const uint8 *y, const uint8 *pcb, const uint8 *pcr, int count, int step) 1906{ 1907 int i; 1908 for (i=0; i < count; ++i) { 1909 int y_fixed = (y[i] << 16) + 32768; // rounding 1910 int r,g,b; 1911 int cr = pcr[i] - 128; 1912 int cb = pcb[i] - 128; 1913 r = y_fixed + cr*float2fixed(1.40200f); 1914 g = y_fixed - cr*float2fixed(0.71414f) - cb*float2fixed(0.34414f); 1915 b = y_fixed + cb*float2fixed(1.77200f); 1916 r >>= 16; 1917 g >>= 16; 1918 b >>= 16; 1919 if ((unsigned) r > 255) { if (r < 0) r = 0; else r = 255; } 1920 if ((unsigned) g > 255) { if (g < 0) g = 0; else g = 255; } 1921 if ((unsigned) b > 255) { if (b < 0) b = 0; else b = 255; } 1922 out[0] = (uint8)r; 1923 out[1] = (uint8)g; 1924 out[2] = (uint8)b; 1925 out[3] = 255; 1926 out += step; 1927 } 1928} 1929 1930#ifdef STBI_SIMD 1931static stbi_YCbCr_to_RGB_run stbi_YCbCr_installed = YCbCr_to_RGB_row; 1932 1933void stbi_install_YCbCr_to_RGB(stbi_YCbCr_to_RGB_run func) 1934{ 1935 stbi_YCbCr_installed = func; 1936} 1937#endif 1938 1939 1940// clean up the temporary component buffers 1941static void cleanup_jpeg(jpeg *j) 1942{ 1943 int i; 1944 for (i=0; i < j->s.img_n; ++i) { 1945 if (j->img_comp[i].data) { 1946 FREE(j->img_comp[i].raw_data); 1947 j->img_comp[i].data = NULL; 1948 } 1949 if (j->img_comp[i].linebuf) { 1950 FREE(j->img_comp[i].linebuf); 1951 j->img_comp[i].linebuf = NULL; 1952 } 1953 } 1954} 1955 1956typedef struct 1957{ 1958 resample_row_func resample; 1959 uint8 *line0,*line1; 1960 int hs,vs; // expansion factor in each axis 1961 int w_lores; // horizontal pixels pre-expansion 1962 int ystep; // how far through vertical expansion we are 1963 int ypos; // which pre-expansion row we're on 1964} stbi_resample; 1965 1966static uint8 *load_jpeg_image(jpeg *z, int *out_x, int *out_y, int *comp, int req_comp) 1967{ 1968 int n, decode_n; 1969 // validate req_comp 1970 if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp", "Internal error"); 1971 z->s.img_n = 0; 1972 1973 // load a jpeg image from whichever source 1974 if (!decode_jpeg_image(z)) { cleanup_jpeg(z); return NULL; } 1975 1976 // determine actual number of components to generate 1977 n = req_comp ? req_comp : z->s.img_n; 1978 1979 if (z->s.img_n == 3 && n < 3) 1980 decode_n = 1; 1981 else 1982 decode_n = z->s.img_n; 1983 1984 // resample and color-convert 1985 { 1986 int k; 1987 uint i,j; 1988 uint8 *output; 1989 uint8 *coutput[4]; 1990 1991 stbi_resample res_comp[4]; 1992 1993 for (k=0; k < decode_n; ++k) { 1994 stbi_resample *r = &res_comp[k]; 1995 1996 // allocate line buffer big enough for upsampling off the edges 1997 // with upsample factor of 4 1998 z->img_comp[k].linebuf = MALLOC(z->s.img_x + 3); 1999 if (!z->img_comp[k].linebuf) { cleanup_jpeg(z); return epuc("outofmem", "Out of memory"); } 2000 2001 r->hs = z->img_h_max / z->img_comp[k].h; 2002 r->vs = z->img_v_max / z->img_comp[k].v; 2003 r->ystep = r->vs >> 1; 2004 r->w_lores = (z->s.img_x + r->hs-1) / r->hs; 2005 r->ypos = 0; 2006 r->line0 = r->line1 = z->img_comp[k].data; 2007 2008 if (r->hs == 1 && r->vs == 1) r->resample = resample_row_1; 2009 else if (r->hs == 1 && r->vs == 2) r->resample = resample_row_v_2; 2010 else if (r->hs == 2 && r->vs == 1) r->resample = resample_row_h_2; 2011 else if (r->hs == 2 && r->vs == 2) r->resample = resample_row_hv_2; 2012 else r->resample = resample_row_generic; 2013 } 2014 2015 // can't error after this so, this is safe 2016 output = MALLOC(n * z->s.img_x * z->s.img_y + 1); 2017 if (!output) { cleanup_jpeg(z); return epuc("outofmem", "Out of memory"); } 2018 2019 // now go ahead and resample 2020 for (j=0; j < z->s.img_y; ++j) { 2021 uint8 *out = output + n * z->s.img_x * j; 2022 for (k=0; k < decode_n; ++k) { 2023 stbi_resample *r = &res_comp[k]; 2024 int y_bot = r->ystep >= (r->vs >> 1); 2025 coutput[k] = r->resample(z->img_comp[k].linebuf, 2026 y_bot ? r->line1 : r->line0, 2027 y_bot ? r->line0 : r->line1, 2028 r->w_lores, r->hs); 2029 if (++r->ystep >= r->vs) { 2030 r->ystep = 0; 2031 r->line0 = r->line1; 2032 if (++r->ypos < z->img_comp[k].y) 2033 r->line1 += z->img_comp[k].w2; 2034 } 2035 } 2036 if (n >= 3) { 2037 uint8 *y = coutput[0]; 2038 if (z->s.img_n == 3) { 2039 #ifdef STBI_SIMD 2040 stbi_YCbCr_installed(out, y, coutput[1], coutput[2], z->s.img_x, n); 2041 #else 2042 YCbCr_to_RGB_row(out, y, coutput[1], coutput[2], z->s.img_x, n); 2043 #endif 2044 } else 2045 for (i=0; i < z->s.img_x; ++i) { 2046 out[0] = out[1] = out[2] = y[i]; 2047 out[3] = 255; // not used if n==3 2048 out += n; 2049 } 2050 } else { 2051 uint8 *y = coutput[0]; 2052 if (n == 1) 2053 for (i=0; i < z->s.img_x; ++i) out[i] = y[i]; 2054 else 2055 for (i=0; i < z->s.img_x; ++i) *out++ = y[i], *out++ = 255; 2056 } 2057 } 2058 cleanup_jpeg(z); 2059 *out_x = z->s.img_x; 2060 *out_y = z->s.img_y; 2061 if (comp) *comp = z->s.img_n; // report original components, not output 2062 return output; 2063 } 2064} 2065 2066#ifndef STBI_NO_STDIO 2067unsigned char *stbi_jpeg_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 2068{ 2069 jpeg j; 2070 start_file(&j.s, f); 2071 return load_jpeg_image(&j, x,y,comp,req_comp); 2072} 2073 2074unsigned char *stbi_jpeg_load(char const *filename, int *x, int *y, int *comp, int req_comp) 2075{ 2076 unsigned char *data; 2077 FILE *f = fopen(filename, "rb"); 2078 if (!f) return NULL; 2079 data = stbi_jpeg_load_from_file(f,x,y,comp,req_comp); 2080 fclose(f); 2081 return data; 2082} 2083#endif 2084 2085unsigned char *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 2086{ 2087 #ifdef STBI_SMALL_STACK 2088 unsigned char *result; 2089 jpeg *j = MALLOC(sizeof(*j)); 2090 start_mem(&j->s, buffer, len); 2091 result = load_jpeg_image(j,x,y,comp,req_comp); 2092 FREE(j); 2093 return result; 2094 #else 2095 jpeg j; 2096 start_mem(&j.s, buffer,len); 2097 return load_jpeg_image(&j, x,y,comp,req_comp); 2098 #endif 2099} 2100 2101static int stbi_jpeg_info_raw(jpeg *j, int *x, int *y, int *comp) 2102{ 2103 if (!decode_jpeg_header(j, SCAN_header)) 2104 return 0; 2105 if (x) *x = j->s.img_x; 2106 if (y) *y = j->s.img_y; 2107 if (comp) *comp = j->s.img_n; 2108 return 1; 2109} 2110 2111#ifndef STBI_NO_STDIO 2112int stbi_jpeg_test_file(FILE *f) 2113{ 2114 int n,r; 2115 jpeg j; 2116 n = ftell(f); 2117 start_file(&j.s, f); 2118 r = decode_jpeg_header(&j, SCAN_type); 2119 fseek(f,n,SEEK_SET); 2120 return r; 2121} 2122 2123int stbi_jpeg_info_from_file(FILE *f, int *x, int *y, int *comp) 2124{ 2125 jpeg j; 2126 long n = ftell(f); 2127 int res; 2128 start_file(&j.s, f); 2129 res = stbi_jpeg_info_raw(&j, x, y, comp); 2130 fseek(f, n, SEEK_SET); 2131 return res; 2132} 2133 2134int stbi_jpeg_info(char const *filename, int *x, int *y, int *comp) 2135{ 2136 FILE *f = fopen(filename, "rb"); 2137 int result; 2138 if (!f) return e("can't fopen", "Unable to open file"); 2139 result = stbi_jpeg_info_from_file(f, x, y, comp); 2140 fclose(f); 2141 return result; 2142} 2143#endif 2144 2145int stbi_jpeg_test_memory(stbi_uc const *buffer, int len) 2146{ 2147 jpeg j; 2148 start_mem(&j.s, buffer,len); 2149 return decode_jpeg_header(&j, SCAN_type); 2150} 2151 2152int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) 2153{ 2154 jpeg j; 2155 start_mem(&j.s, buffer, len); 2156 return stbi_jpeg_info_raw(&j, x, y, comp); 2157} 2158 2159#ifndef STBI_NO_STDIO 2160extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp); 2161extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp); 2162#endif 2163extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); 2164 2165// public domain zlib decode v0.2 Sean Barrett 2006-11-18 2166// simple implementation 2167// - all input must be provided in an upfront buffer 2168// - all output is written to a single output buffer (can malloc/realloc) 2169// performance 2170// - fast huffman 2171 2172// fast-way is faster to check than jpeg huffman, but slow way is slower 2173#define ZFAST_BITS 9 // accelerate all cases in default tables 2174#define ZFAST_MASK ((1 << ZFAST_BITS) - 1) 2175 2176// zlib-style huffman encoding 2177// (jpegs packs from left, zlib from right, so can't share code) 2178typedef struct 2179{ 2180 uint16 fast[1 << ZFAST_BITS]; 2181 uint16 firstcode[16]; 2182 int maxcode[17]; 2183 uint16 firstsymbol[16]; 2184 uint8 size[288]; 2185 uint16 value[288]; 2186} zhuffman; 2187 2188__forceinline static int bitreverse16(int n) 2189{ 2190 n = ((n & 0xAAAA) >> 1) | ((n & 0x5555) << 1); 2191 n = ((n & 0xCCCC) >> 2) | ((n & 0x3333) << 2); 2192 n = ((n & 0xF0F0) >> 4) | ((n & 0x0F0F) << 4); 2193 n = ((n & 0xFF00) >> 8) | ((n & 0x00FF) << 8); 2194 return n; 2195} 2196 2197__forceinline static int bit_reverse(int v, int bits) 2198{ 2199 assert(bits <= 16); 2200 // to bit reverse n bits, reverse 16 and shift 2201 // e.g. 11 bits, bit reverse and shift away 5 2202 return bitreverse16(v) >> (16-bits); 2203} 2204 2205static int zbuild_huffman(zhuffman *z, uint8 *sizelist, int num) 2206{ 2207 int i,k=0; 2208 int code, next_code[16], sizes[17]; 2209 2210 // DEFLATE spec for generating codes 2211 memset(sizes, 0, sizeof(sizes)); 2212 memset(z->fast, 255, sizeof(z->fast)); 2213 for (i=0; i < num; ++i) 2214 ++sizes[sizelist[i]]; 2215 sizes[0] = 0; 2216 for (i=1; i < 16; ++i) 2217 assert(sizes[i] <= (1 << i)); 2218 code = 0; 2219 for (i=1; i < 16; ++i) { 2220 next_code[i] = code; 2221 z->firstcode[i] = (uint16) code; 2222 z->firstsymbol[i] = (uint16) k; 2223 code = (code + sizes[i]); 2224 if (sizes[i]) 2225 if (code-1 >= (1 << i)) return e("bad codelengths","Corrupt JPEG"); 2226 z->maxcode[i] = code << (16-i); // preshift for inner loop 2227 code <<= 1; 2228 k += sizes[i]; 2229 } 2230 z->maxcode[16] = 0x10000; // sentinel 2231 for (i=0; i < num; ++i) { 2232 int s = sizelist[i]; 2233 if (s) { 2234 int c = next_code[s] - z->firstcode[s] + z->firstsymbol[s]; 2235 z->size[c] = (uint8)s; 2236 z->value[c] = (uint16)i; 2237 if (s <= ZFAST_BITS) { 2238 int m = bit_reverse(next_code[s],s); 2239 while (m < (1 << ZFAST_BITS)) { 2240 z->fast[m] = (uint16) c; 2241 m += (1 << s); 2242 } 2243 } 2244 ++next_code[s]; 2245 } 2246 } 2247 return 1; 2248} 2249 2250// zlib-from-memory implementation for PNG reading 2251// because PNG allows splitting the zlib stream arbitrarily, 2252// and it's annoying structurally to have PNG call ZLIB call PNG, 2253// we require PNG read all the IDATs and combine them into a single 2254// memory buffer 2255 2256typedef struct 2257{ 2258 uint8 const *zbuffer, *zbuffer_end; 2259 int num_bits; 2260 uint32 code_buffer; 2261 2262 char *zout; 2263 char *zout_start; 2264 char *zout_end; 2265 int z_expandable; 2266 2267 zhuffman z_length, z_distance; 2268} zbuf; 2269 2270__forceinline static int zget8(zbuf *z) 2271{ 2272 if (z->zbuffer >= z->zbuffer_end) return 0; 2273 return *z->zbuffer++; 2274} 2275 2276static void fill_bits(zbuf *z) 2277{ 2278 do { 2279 assert(z->code_buffer < (1U << z->num_bits)); 2280 z->code_buffer |= zget8(z) << z->num_bits; 2281 z->num_bits += 8; 2282 } while (z->num_bits <= 24); 2283} 2284 2285__forceinline static unsigned int zreceive(zbuf *z, int n) 2286{ 2287 unsigned int k; 2288 if (z->num_bits < n) fill_bits(z); 2289 k = z->code_buffer & ((1 << n) - 1); 2290 z->code_buffer >>= n; 2291 z->num_bits -= n; 2292 return k; 2293} 2294 2295__forceinline static int zhuffman_decode(zbuf *a, zhuffman *z) 2296{ 2297 int b,s,k; 2298 if (a->num_bits < 16) fill_bits(a); 2299 b = z->fast[a->code_buffer & ZFAST_MASK]; 2300 if (b < 0xffff) { 2301 s = z->size[b]; 2302 a->code_buffer >>= s; 2303 a->num_bits -= s; 2304 return z->value[b]; 2305 } 2306 2307 // not resolved by fast table, so compute it the slow way 2308 // use jpeg approach, which requires MSbits at top 2309 k = bit_reverse(a->code_buffer, 16); 2310 for (s=ZFAST_BITS+1; ; ++s) 2311 if (k < z->maxcode[s]) 2312 break; 2313 if (s == 16) return -1; // invalid code! 2314 // code size is s, so: 2315 b = (k >> (16-s)) - z->firstcode[s] + z->firstsymbol[s]; 2316 assert(z->size[b] == s); 2317 a->code_buffer >>= s; 2318 a->num_bits -= s; 2319 return z->value[b]; 2320} 2321 2322static int expand(zbuf *z, int n) // need to make room for n bytes 2323{ 2324 char *q; 2325 int cur, limit; 2326 if (!z->z_expandable) return e("output buffer limit","Corrupt PNG"); 2327 cur = (int) (z->zout - z->zout_start); 2328 limit = (int) (z->zout_end - z->zout_start); 2329 while (cur + n > limit) 2330 limit *= 2; 2331 q = (char *) REALLOC(z->zout_start, limit); 2332 if (q == NULL) return e("outofmem", "Out of memory"); 2333 z->zout_start = q; 2334 z->zout = q + cur; 2335 z->zout_end = q + limit; 2336 return 1; 2337} 2338 2339static int length_base[31] = { 2340 3,4,5,6,7,8,9,10,11,13, 2341 15,17,19,23,27,31,35,43,51,59, 2342 67,83,99,115,131,163,195,227,258,0,0 }; 2343 2344static int length_extra[31]= 2345{ 0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0,0,0 }; 2346 2347static int dist_base[32] = { 1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193, 2348257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577,0,0}; 2349 2350static int dist_extra[32] = 2351{ 0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13}; 2352 2353static int parse_huffman_block(zbuf *a) 2354{ 2355 for(;;) { 2356 int z = zhuffman_decode(a, &a->z_length); 2357 if (z < 256) { 2358 if (z < 0) return e("bad huffman code","Corrupt PNG"); // error in huffman codes 2359 if (a->zout >= a->zout_end) if (!expand(a, 1)) return 0; 2360 *a->zout++ = (char) z; 2361 } else { 2362 uint8 *p; 2363 int len,dist; 2364 if (z == 256) return 1; 2365 z -= 257; 2366 len = length_base[z]; 2367 if (length_extra[z]) len += zreceive(a, length_extra[z]); 2368 z = zhuffman_decode(a, &a->z_distance); 2369 if (z < 0) return e("bad huffman code","Corrupt PNG"); 2370 dist = dist_base[z]; 2371 if (dist_extra[z]) dist += zreceive(a, dist_extra[z]); 2372 if (a->zout - a->zout_start < dist) return e("bad dist","Corrupt PNG"); 2373 if (a->zout + len > a->zout_end) if (!expand(a, len)) return 0; 2374 p = (uint8 *) (a->zout - dist); 2375 while (len--) 2376 *a->zout++ = *p++; 2377 } 2378 } 2379} 2380 2381static int compute_huffman_codes(zbuf *a) 2382{ 2383 static uint8 length_dezigzag[19] = { 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 }; 2384 zhuffman z_codelength; 2385 uint8 lencodes[286+32+137];//padding for maximum single op 2386 uint8 codelength_sizes[19]; 2387 int i,n; 2388 2389 int hlit = zreceive(a,5) + 257; 2390 int hdist = zreceive(a,5) + 1; 2391 int hclen = zreceive(a,4) + 4; 2392 2393 memset(codelength_sizes, 0, sizeof(codelength_sizes)); 2394 for (i=0; i < hclen; ++i) { 2395 int s = zreceive(a,3); 2396 codelength_sizes[length_dezigzag[i]] = (uint8) s; 2397 } 2398 if (!zbuild_huffman(&z_codelength, codelength_sizes, 19)) return 0; 2399 2400 n = 0; 2401 while (n < hlit + hdist) { 2402 int c = zhuffman_decode(a, &z_codelength); 2403 assert(c >= 0 && c < 19); 2404 if (c < 16) 2405 lencodes[n++] = (uint8) c; 2406 else if (c == 16) { 2407 c = zreceive(a,2)+3; 2408 memset(lencodes+n, lencodes[n-1], c); 2409 n += c; 2410 } else if (c == 17) { 2411 c = zreceive(a,3)+3; 2412 memset(lencodes+n, 0, c); 2413 n += c; 2414 } else { 2415 assert(c == 18); 2416 c = zreceive(a,7)+11; 2417 memset(lencodes+n, 0, c); 2418 n += c; 2419 } 2420 } 2421 if (n != hlit+hdist) return e("bad codelengths","Corrupt PNG"); 2422 if (!zbuild_huffman(&a->z_length, lencodes, hlit)) return 0; 2423 if (!zbuild_huffman(&a->z_distance, lencodes+hlit, hdist)) return 0; 2424 return 1; 2425} 2426 2427static int parse_uncompressed_block(zbuf *a) 2428{ 2429 uint8 header[4]; 2430 int len,nlen,k; 2431 if (a->num_bits & 7) 2432 zreceive(a, a->num_bits & 7); // discard 2433 // drain the bit-packed data into header 2434 k = 0; 2435 while (a->num_bits > 0) { 2436 header[k++] = (uint8) (a->code_buffer & 255); // wtf this warns? 2437 a->code_buffer >>= 8; 2438 a->num_bits -= 8; 2439 } 2440 assert(a->num_bits == 0); 2441 // now fill header the normal way 2442 while (k < 4) 2443 header[k++] = (uint8) zget8(a); 2444 len = header[1] * 256 + header[0]; 2445 nlen = header[3] * 256 + header[2]; 2446 if (nlen != (len ^ 0xffff)) return e("zlib corrupt","Corrupt PNG"); 2447 if (a->zbuffer + len > a->zbuffer_end) return e("read past buffer","Corrupt PNG"); 2448 if (a->zout + len > a->zout_end) 2449 if (!expand(a, len)) return 0; 2450 memcpy(a->zout, a->zbuffer, len); 2451 a->zbuffer += len; 2452 a->zout += len; 2453 return 1; 2454} 2455 2456static int parse_zlib_header(zbuf *a) 2457{ 2458 int cmf = zget8(a); 2459 int cm = cmf & 15; 2460 /* int cinfo = cmf >> 4; */ 2461 int flg = zget8(a); 2462 if ((cmf*256+flg) % 31 != 0) return e("bad zlib header","Corrupt PNG"); // zlib spec 2463 if (flg & 32) return e("no preset dict","Corrupt PNG"); // preset dictionary not allowed in png 2464 if (cm != 8) return e("bad compression","Corrupt PNG"); // DEFLATE required for png 2465 // window = 1 << (8 + cinfo)... but who cares, we fully buffer output 2466 return 1; 2467} 2468 2469// @TODO: should statically initialize these for optimal thread safety 2470static uint8 default_length[288], default_distance[32]; 2471static void init_defaults(void) 2472{ 2473 int i; // use <= to match clearly with spec 2474 for (i=0; i <= 143; ++i) default_length[i] = 8; 2475 for ( ; i <= 255; ++i) default_length[i] = 9; 2476 for ( ; i <= 279; ++i) default_length[i] = 7; 2477 for ( ; i <= 287; ++i) default_length[i] = 8; 2478 2479 for (i=0; i <= 31; ++i) default_distance[i] = 5; 2480} 2481 2482int stbi_png_partial; // a quick hack to only allow decoding some of a PNG... I should implement real streaming support instead 2483static int parse_zlib(zbuf *a, int parse_header) 2484{ 2485 int final, type; 2486 if (parse_header) 2487 if (!parse_zlib_header(a)) return 0; 2488 a->num_bits = 0; 2489 a->code_buffer = 0; 2490 do { 2491 final = zreceive(a,1); 2492 type = zreceive(a,2); 2493 if (type == 0) { 2494 if (!parse_uncompressed_block(a)) return 0; 2495 } else if (type == 3) { 2496 return 0; 2497 } else { 2498 if (type == 1) { 2499 // use fixed code lengths 2500 if (!default_distance[31]) init_defaults(); 2501 if (!zbuild_huffman(&a->z_length , default_length , 288)) return 0; 2502 if (!zbuild_huffman(&a->z_distance, default_distance, 32)) return 0; 2503 } else { 2504 if (!compute_huffman_codes(a)) return 0; 2505 } 2506 if (!parse_huffman_block(a)) return 0; 2507 } 2508 if (stbi_png_partial && a->zout - a->zout_start > 65536) 2509 break; 2510 } while (!final); 2511 return 1; 2512} 2513 2514static int do_zlib(zbuf *a, char *obuf, int olen, int exp, int parse_header) 2515{ 2516 a->zout_start = obuf; 2517 a->zout = obuf; 2518 a->zout_end = obuf + olen; 2519 a->z_expandable = exp; 2520 2521 return parse_zlib(a, parse_header); 2522} 2523 2524char *stbi_zlib_decode_malloc_guesssize(const char * buffer, int len, int initial_size, int *outlen) 2525{ 2526 zbuf a; 2527 char *p = MALLOC(initial_size); 2528 if (p == NULL) return NULL; 2529 a.zbuffer = (uint8 const *) buffer; 2530 a.zbuffer_end = (uint8 const *) buffer + len; 2531 if (do_zlib(&a, p, initial_size, 1, 1)) { 2532 if (outlen) *outlen = (int) (a.zout - a.zout_start); 2533 return a.zout_start; 2534 } else { 2535 FREE(a.zout_start); 2536 return NULL; 2537 } 2538} 2539 2540char *stbi_zlib_decode_malloc(char const *buffer, int len, int *outlen) 2541{ 2542 return stbi_zlib_decode_malloc_guesssize(buffer, len, 16384, outlen); 2543} 2544 2545char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header) 2546{ 2547 zbuf a; 2548 char *p = MALLOC(initial_size); 2549 if (p == NULL) return NULL; 2550 a.zbuffer = (uint8 const *) buffer; 2551 a.zbuffer_end = (uint8 const *) buffer + len; 2552 if (do_zlib(&a, p, initial_size, 1, parse_header)) { 2553 if (outlen) *outlen = (int) (a.zout - a.zout_start); 2554 return a.zout_start; 2555 } else { 2556 FREE(a.zout_start); 2557 return NULL; 2558 } 2559} 2560 2561int stbi_zlib_decode_buffer(char *obuffer, int olen, char const *ibuffer, int ilen) 2562{ 2563 zbuf a; 2564 a.zbuffer = (uint8 const *) ibuffer; 2565 a.zbuffer_end = (uint8 const *) ibuffer + ilen; 2566 if (do_zlib(&a, obuffer, olen, 0, 1)) 2567 return (int) (a.zout - a.zout_start); 2568 else 2569 return -1; 2570} 2571 2572char *stbi_zlib_decode_noheader_malloc(char const *buffer, int len, int *outlen) 2573{ 2574 zbuf a; 2575 char *p = MALLOC(16384); 2576 if (p == NULL) return NULL; 2577 a.zbuffer = (uint8 const *) buffer; 2578 a.zbuffer_end = (uint8 const *) buffer+len; 2579 if (do_zlib(&a, p, 16384, 1, 0)) { 2580 if (outlen) *outlen = (int) (a.zout - a.zout_start); 2581 return a.zout_start; 2582 } else { 2583 FREE(a.zout_start); 2584 return NULL; 2585 } 2586} 2587 2588int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen) 2589{ 2590 zbuf a; 2591 a.zbuffer = (uint8 const *) ibuffer; 2592 a.zbuffer_end = (uint8 const *) ibuffer + ilen; 2593 if (do_zlib(&a, obuffer, olen, 0, 0)) 2594 return (int) (a.zout - a.zout_start); 2595 else 2596 return -1; 2597} 2598 2599// public domain "baseline" PNG decoder v0.10 Sean Barrett 2006-11-18 2600// simple implementation 2601// - only 8-bit samples 2602// - no CRC checking 2603// - allocates lots of intermediate memory 2604// - avoids problem of streaming data between subsystems 2605// - avoids explicit window management 2606// performance 2607// - uses stb_zlib, a PD zlib implementation with fast huffman decoding 2608 2609 2610typedef struct 2611{ 2612 uint32 length; 2613 uint32 type; 2614} chunk; 2615 2616#define PNG_TYPE(a,b,c,d) (((a) << 24) + ((b) << 16) + ((c) << 8) + (d)) 2617 2618static chunk get_chunk_header(stbi *s) 2619{ 2620 chunk c; 2621 c.length = get32(s); 2622 c.type = get32(s); 2623 return c; 2624} 2625 2626static int check_png_header(stbi *s) 2627{ 2628 static uint8 png_sig[8] = { 137,80,78,71,13,10,26,10 }; 2629 int i; 2630 for (i=0; i < 8; ++i) 2631 if (get8(s) != png_sig[i]) return e("bad png sig","Not a PNG"); 2632 return 1; 2633} 2634 2635typedef struct 2636{ 2637 stbi s; 2638 uint8 *idata, *expanded, *out; 2639} png; 2640 2641 2642enum { 2643 F_none=0, F_sub=1, F_up=2, F_avg=3, F_paeth=4, 2644 F_avg_first, F_paeth_first 2645}; 2646 2647static uint8 first_row_filter[5] = 2648{ 2649 F_none, F_sub, F_none, F_avg_first, F_paeth_first 2650}; 2651 2652static int paeth(int a, int b, int c) 2653{ 2654 int p = a + b - c; 2655 int pa = abs(p-a); 2656 int pb = abs(p-b); 2657 int pc = abs(p-c); 2658 if (pa <= pb && pa <= pc) return a; 2659 if (pb <= pc) return b; 2660 return c; 2661} 2662 2663// create the png data from post-deflated data 2664static int create_png_image_raw(png *a, uint8 *raw, uint32 raw_len, int out_n, uint32 x, uint32 y) 2665{ 2666 stbi *s = &a->s; 2667 uint32 i,j,stride = x*out_n; 2668 int k; 2669 int img_n = s->img_n; // copy it into a local for later 2670 assert(out_n == s->img_n || out_n == s->img_n+1); 2671 if (stbi_png_partial) y = 1; 2672 a->out = MALLOC(x * y * out_n); 2673 if (!a->out) return e("outofmem", "Out of memory"); 2674 if (!stbi_png_partial) { 2675 if (s->img_x == x && s->img_y == y) { 2676 if (raw_len != (img_n * x + 1) * y) return e("not enough pixels","Corrupt PNG"); 2677 } else { // interlaced: 2678 if (raw_len < (img_n * x + 1) * y) return e("not enough pixels","Corrupt PNG"); 2679 } 2680 } 2681 for (j=0; j < y; ++j) { 2682 uint8 *cur = a->out + stride*j; 2683 uint8 *prior = cur - stride; 2684 int filter = *raw++; 2685 if (filter > 4) return e("invalid filter","Corrupt PNG"); 2686 // if first row, use special filter that doesn't sample previous row 2687 if (j == 0) filter = first_row_filter[filter]; 2688 // handle first pixel explicitly 2689 for (k=0; k < img_n; ++k) { 2690 switch (filter) { 2691 case F_none : cur[k] = raw[k]; break; 2692 case F_sub : cur[k] = raw[k]; break; 2693 case F_up : cur[k] = raw[k] + prior[k]; break; 2694 case F_avg : cur[k] = raw[k] + (prior[k]>>1); break; 2695 case F_paeth : cur[k] = (uint8) (raw[k] + paeth(0,prior[k],0)); break; 2696 case F_avg_first : cur[k] = raw[k]; break; 2697 case F_paeth_first: cur[k] = raw[k]; break; 2698 } 2699 } 2700 if (img_n != out_n) cur[img_n] = 255; 2701 raw += img_n; 2702 cur += out_n; 2703 prior += out_n; 2704 // this is a little gross, so that we don't switch per-pixel or per-component 2705 if (img_n == out_n) { 2706 #define CASE(f) \ 2707 case f: \ 2708 for (i=x-1; i >= 1; --i, raw+=img_n,cur+=img_n,prior+=img_n) \ 2709 for (k=0; k < img_n; ++k) 2710 switch (filter) { 2711 CASE(F_none) cur[k] = raw[k]; 2712 break; 2713 CASE(F_sub) cur[k] = raw[k] + cur[k-img_n]; 2714 break; 2715 CASE(F_up) cur[k] = raw[k] + prior[k]; 2716 break; 2717 CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-img_n])>>1); 2718 break; 2719 CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],prior[k],prior[k-img_n])); 2720 break; 2721 CASE(F_avg_first) cur[k] = raw[k] + (cur[k-img_n] >> 1); 2722 break; 2723 CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],0,0)); 2724 break; 2725 } 2726 #undef CASE 2727 } else { 2728 assert(img_n+1 == out_n); 2729 #define CASE(f) \ 2730 case f: \ 2731 for (i=x-1; i >= 1; --i, cur[img_n]=255,raw+=img_n,cur+=out_n,prior+=out_n) \ 2732 for (k=0; k < img_n; ++k) 2733 switch (filter) { 2734 CASE(F_none) cur[k] = raw[k]; 2735 break; 2736 CASE(F_sub) cur[k] = raw[k] + cur[k-out_n]; 2737 break; 2738 CASE(F_up) cur[k] = raw[k] + prior[k]; 2739 break; 2740 CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-out_n])>>1); 2741 break; 2742 CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],prior[k],prior[k-out_n])); 2743 break; 2744 CASE(F_avg_first) cur[k] = raw[k] + (cur[k-out_n] >> 1); 2745 break; 2746 CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],0,0)); 2747 break; 2748 } 2749 #undef CASE 2750 } 2751 } 2752 return 1; 2753} 2754 2755static int create_png_image(png *a, uint8 *raw, uint32 raw_len, int out_n, int interlaced) 2756{ 2757 uint8 *final; 2758 int p; 2759 int save; 2760 if (!interlaced) 2761 return create_png_image_raw(a, raw, raw_len, out_n, a->s.img_x, a->s.img_y); 2762 save = stbi_png_partial; 2763 stbi_png_partial = 0; 2764 2765 // de-interlacing 2766 final = MALLOC(a->s.img_x * a->s.img_y * out_n); 2767 for (p=0; p < 7; ++p) { 2768 int xorig[] = { 0,4,0,2,0,1,0 }; 2769 int yorig[] = { 0,0,4,0,2,0,1 }; 2770 int xspc[] = { 8,8,4,4,2,2,1 }; 2771 int yspc[] = { 8,8,8,4,4,2,2 }; 2772 int i,j,x,y; 2773 // pass1_x[4] = 0, pass1_x[5] = 1, pass1_x[12] = 1 2774 x = (a->s.img_x - xorig[p] + xspc[p]-1) / xspc[p]; 2775 y = (a->s.img_y - yorig[p] + yspc[p]-1) / yspc[p]; 2776 if (x && y) { 2777 if (!create_png_image_raw(a, raw, raw_len, out_n, x, y)) { 2778 FREE(final); 2779 return 0; 2780 } 2781 for (j=0; j < y; ++j) 2782 for (i=0; i < x; ++i) 2783 memcpy(final + (j*yspc[p]+yorig[p])*a->s.img_x*out_n + (i*xspc[p]+xorig[p])*out_n, 2784 a->out + (j*x+i)*out_n, out_n); 2785 FREE(a->out); 2786 raw += (x*out_n+1)*y; 2787 raw_len -= (x*out_n+1)*y; 2788 } 2789 } 2790 a->out = final; 2791 2792 stbi_png_partial = save; 2793 return 1; 2794} 2795 2796static int compute_transparency(png *z, uint8 tc[3], int out_n) 2797{ 2798 stbi *s = &z->s; 2799 uint32 i, pixel_count = s->img_x * s->img_y; 2800 uint8 *p = z->out; 2801 2802 // compute color-based transparency, assuming we've 2803 // already got 255 as the alpha value in the output 2804 assert(out_n == 2 || out_n == 4); 2805 2806 if (out_n == 2) { 2807 for (i=0; i < pixel_count; ++i) { 2808 p[1] = (p[0] == tc[0] ? 0 : 255); 2809 p += 2; 2810 } 2811 } else { 2812 for (i=0; i < pixel_count; ++i) { 2813 if (p[0] == tc[0] && p[1] == tc[1] && p[2] == tc[2]) 2814 p[3] = 0; 2815 p += 4; 2816 } 2817 } 2818 return 1; 2819} 2820 2821static int expand_palette(png *a, uint8 *palette, int len, int pal_img_n) 2822{ 2823 uint32 i, pixel_count = a->s.img_x * a->s.img_y; 2824 uint8 *p, *temp_out, *orig = a->out; 2825 2826 p = MALLOC(pixel_count * pal_img_n); 2827 if (p == NULL) return e("outofmem", "Out of memory"); 2828 2829 // between here and FREE(out) below, exiting would leak 2830 temp_out = p; 2831 2832 if (pal_img_n == 3) { 2833 for (i=0; i < pixel_count; ++i) { 2834 int n = orig[i]*4; 2835 p[0] = palette[n ]; 2836 p[1] = palette[n+1]; 2837 p[2] = palette[n+2]; 2838 p += 3; 2839 } 2840 } else { 2841 for (i=0; i < pixel_count; ++i) { 2842 int n = orig[i]*4; 2843 p[0] = palette[n ]; 2844 p[1] = palette[n+1]; 2845 p[2] = palette[n+2]; 2846 p[3] = palette[n+3]; 2847 p += 4; 2848 } 2849 } 2850 FREE(a->out); 2851 a->out = temp_out; 2852 2853 STBI_NOTUSED(len); 2854 2855 return 1; 2856} 2857 2858static int stbi_unpremultiply_on_load = 0; 2859static int stbi_de_iphone_flag = 0; 2860 2861void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply) 2862{ 2863 stbi_unpremultiply_on_load = flag_true_if_should_unpremultiply; 2864} 2865void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert) 2866{ 2867 stbi_de_iphone_flag = flag_true_if_should_convert; 2868} 2869 2870static void stbi_de_iphone(png *z) 2871{ 2872 stbi *s = &z->s; 2873 uint32 i, pixel_count = s->img_x * s->img_y; 2874 uint8 *p = z->out; 2875 2876 if (s->img_out_n == 3) { // convert bgr to rgb 2877 for (i=0; i < pixel_count; ++i) { 2878 uint8 t = p[0]; 2879 p[0] = p[2]; 2880 p[2] = t; 2881 p += 3; 2882 } 2883 } else { 2884 assert(s->img_out_n == 4); 2885 if (stbi_unpremultiply_on_load) { 2886 // convert bgr to rgb and unpremultiply 2887 for (i=0; i < pixel_count; ++i) { 2888 uint8 a = p[3]; 2889 uint8 t = p[0]; 2890 if (a) { 2891 p[0] = p[2] * 255 / a; 2892 p[1] = p[1] * 255 / a; 2893 p[2] = t * 255 / a; 2894 } else { 2895 p[0] = p[2]; 2896 p[2] = t; 2897 } 2898 p += 4; 2899 } 2900 } else { 2901 // convert bgr to rgb 2902 for (i=0; i < pixel_count; ++i) { 2903 uint8 t = p[0]; 2904 p[0] = p[2]; 2905 p[2] = t; 2906 p += 4; 2907 } 2908 } 2909 } 2910} 2911 2912static int parse_png_file(png *z, int scan, int req_comp) 2913{ 2914 uint8 palette[1024], pal_img_n=0; 2915 uint8 has_trans=0, tc[3]; 2916 uint32 ioff=0, idata_limit=0, i, pal_len=0; 2917 int first=1,k,interlace=0, iphone=0; 2918 stbi *s = &z->s; 2919 2920 if (!check_png_header(s)) return 0; 2921 2922 if (scan == SCAN_type) return 1; 2923 2924 for (;;) { 2925 chunk c = get_chunk_header(s); 2926 switch (c.type) { 2927 case PNG_TYPE('C','g','B','I'): 2928 iphone = stbi_de_iphone_flag; 2929 skip(s, c.length); 2930 break; 2931 case PNG_TYPE('I','H','D','R'): { 2932 int depth,color,comp,filter; 2933 if (!first) return e("multiple IHDR","Corrupt PNG"); 2934 first = 0; 2935 if (c.length != 13) return e("bad IHDR len","Corrupt PNG"); 2936 s->img_x = get32(s); if (s->img_x > (1 << 24)) return e("too large","Very large image (corrupt?)"); 2937 s->img_y = get32(s); if (s->img_y > (1 << 24)) return e("too large","Very large image (corrupt?)"); 2938 depth = get8(s); if (depth != 8) return e("8bit only","PNG not supported: 8-bit only"); 2939 color = get8(s); if (color > 6) return e("bad ctype","Corrupt PNG"); 2940 if (color == 3) pal_img_n = 3; else if (color & 1) return e("bad ctype","Corrupt PNG"); 2941 comp = get8(s); if (comp) return e("bad comp method","Corrupt PNG"); 2942 filter= get8(s); if (filter) return e("bad filter method","Corrupt PNG"); 2943 interlace = get8(s); if (interlace>1) return e("bad interlace method","Corrupt PNG"); 2944 if (!s->img_x || !s->img_y) return e("0-pixel image","Corrupt PNG"); 2945 if (!pal_img_n) { 2946 s->img_n = (color & 2 ? 3 : 1) + (color & 4 ? 1 : 0); 2947 if ((1 << 30) / s->img_x / s->img_n < s->img_y) return e("too large", "Image too large to decode"); 2948 if (scan == SCAN_header) return 1; 2949 } else { 2950 // if paletted, then pal_n is our final components, and 2951 // img_n is # components to decompress/filter. 2952 s->img_n = 1; 2953 if ((1 << 30) / s->img_x / 4 < s->img_y) return e("too large","Corrupt PNG"); 2954 // if SCAN_header, have to scan to see if we have a tRNS 2955 } 2956 break; 2957 } 2958 2959 case PNG_TYPE('P','L','T','E'): { 2960 if (first) return e("first not IHDR", "Corrupt PNG"); 2961 if (c.length > 256*3) return e("invalid PLTE","Corrupt PNG"); 2962 pal_len = c.length / 3; 2963 if (pal_len * 3 != c.length) return e("invalid PLTE","Corrupt PNG"); 2964 for (i=0; i < pal_len; ++i) { 2965 palette[i*4+0] = get8u(s); 2966 palette[i*4+1] = get8u(s); 2967 palette[i*4+2] = get8u(s); 2968 palette[i*4+3] = 255; 2969 } 2970 break; 2971 } 2972 2973 case PNG_TYPE('t','R','N','S'): { 2974 if (first) return e("first not IHDR", "Corrupt PNG"); 2975 if (z->idata) return e("tRNS after IDAT","Corrupt PNG"); 2976 if (pal_img_n) { 2977 if (scan == SCAN_header) { s->img_n = 4; return 1; } 2978 if (pal_len == 0) return e("tRNS before PLTE","Corrupt PNG"); 2979 if (c.length > pal_len) return e("bad tRNS len","Corrupt PNG"); 2980 pal_img_n = 4; 2981 for (i=0; i < c.length; ++i) 2982 palette[i*4+3] = get8u(s); 2983 } else { 2984 if (!(s->img_n & 1)) return e("tRNS with alpha","Corrupt PNG"); 2985 if (c.length != (uint32) s->img_n*2) return e("bad tRNS len","Corrupt PNG"); 2986 has_trans = 1; 2987 for (k=0; k < s->img_n; ++k) 2988 tc[k] = (uint8) get16(s); // non 8-bit images will be larger 2989 } 2990 break; 2991 } 2992 2993 case PNG_TYPE('I','D','A','T'): { 2994 if (first) return e("first not IHDR", "Corrupt PNG"); 2995 if (pal_img_n && !pal_len) return e("no PLTE","Corrupt PNG"); 2996 if (scan == SCAN_header) { s->img_n = pal_img_n; return 1; } 2997 if (ioff + c.length > idata_limit) { 2998 uint8 *p; 2999 if (idata_limit == 0) idata_limit = c.length > 4096 ? c.length : 4096; 3000 while (ioff + c.length > idata_limit) 3001 idata_limit *= 2; 3002 p = (uint8 *) REALLOC(z->idata, idata_limit); if (p == NULL) return e("outofmem", "Out of memory"); 3003 z->idata = p; 3004 } 3005 if (!getn(s, z->idata+ioff,c.length)) return e("outofdata","Corrupt PNG"); 3006 ioff += c.length; 3007 break; 3008 } 3009 3010 case PNG_TYPE('I','E','N','D'): { 3011 uint32 raw_len; 3012 if (first) return e("first not IHDR", "Corrupt PNG"); 3013 if (scan != SCAN_load) return 1; 3014 if (z->idata == NULL) return e("no IDAT","Corrupt PNG"); 3015 z->expanded = (uint8 *) stbi_zlib_decode_malloc_guesssize_headerflag((char *) z->idata, ioff, 16384, (int *) &raw_len, !iphone); 3016 if (z->expanded == NULL) return 0; // zlib should set error 3017 FREE(z->idata); z->idata = NULL; 3018 if ((req_comp == s->img_n+1 && req_comp != 3 && !pal_img_n) || has_trans) 3019 s->img_out_n = s->img_n+1; 3020 else 3021 s->img_out_n = s->img_n; 3022 if (!create_png_image(z, z->expanded, raw_len, s->img_out_n, interlace)) return 0; 3023 if (has_trans) 3024 if (!compute_transparency(z, tc, s->img_out_n)) return 0; 3025 if (iphone && s->img_out_n > 2) 3026 stbi_de_iphone(z); 3027 if (pal_img_n) { 3028 // pal_img_n == 3 or 4 3029 s->img_n = pal_img_n; // record the actual colors we had 3030 s->img_out_n = pal_img_n; 3031 if (req_comp >= 3) s->img_out_n = req_comp; 3032 if (!expand_palette(z, palette, pal_len, s->img_out_n)) 3033 return 0; 3034 } 3035 FREE(z->expanded); z->expanded = NULL; 3036 return 1; 3037 } 3038 3039 default: 3040 // if critical, fail 3041 if (first) return e("first not IHDR", "Corrupt PNG"); 3042 if ((c.type & (1 << 29)) == 0) { 3043 #ifndef STBI_NO_FAILURE_STRINGS 3044 // not threadsafe 3045 static char invalid_chunk[] = "XXXX chunk not known"; 3046 invalid_chunk[0] = (uint8) (c.type >> 24); 3047 invalid_chunk[1] = (uint8) (c.type >> 16); 3048 invalid_chunk[2] = (uint8) (c.type >> 8); 3049 invalid_chunk[3] = (uint8) (c.type >> 0); 3050 #endif 3051 return e(invalid_chunk, "PNG not supported: unknown chunk type"); 3052 } 3053 skip(s, c.length); 3054 break; 3055 } 3056 // end of chunk, read and skip CRC 3057 get32(s); 3058 } 3059} 3060 3061static unsigned char *do_png(png *p, int *x, int *y, int *n, int req_comp) 3062{ 3063 unsigned char *result=NULL; 3064 p->expanded = NULL; 3065 p->idata = NULL; 3066 p->out = NULL; 3067 if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp", "Internal error"); 3068 if (parse_png_file(p, SCAN_load, req_comp)) { 3069 result = p->out; 3070 p->out = NULL; 3071 if (req_comp && req_comp != p->s.img_out_n) { 3072 result = convert_format(result, p->s.img_out_n, req_comp, p->s.img_x, p->s.img_y); 3073 p->s.img_out_n = req_comp; 3074 if (result == NULL) return result; 3075 } 3076 *x = p->s.img_x; 3077 *y = p->s.img_y; 3078 if (n) *n = p->s.img_n; 3079 } 3080 FREE(p->expanded); p->expanded = NULL; 3081 FREE(p->idata); p->idata = NULL; 3082 3083 return result; 3084} 3085 3086#ifndef STBI_NO_STDIO 3087unsigned char *stbi_png_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 3088{ 3089 png p; 3090 start_file(&p.s, f); 3091 return do_png(&p, x,y,comp,req_comp); 3092} 3093 3094unsigned char *stbi_png_load(char const *filename, int *x, int *y, int *comp, int req_comp) 3095{ 3096 unsigned char *data; 3097 FILE *f = fopen(filename, "rb"); 3098 if (!f) return NULL; 3099 data = stbi_png_load_from_file(f,x,y,comp,req_comp); 3100 fclose(f); 3101 return data; 3102} 3103#endif 3104 3105unsigned char *stbi_png_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 3106{ 3107 png p; 3108 start_mem(&p.s, buffer,len); 3109 return do_png(&p, x,y,comp,req_comp); 3110} 3111 3112#ifndef STBI_NO_STDIO 3113int stbi_png_test_file(FILE *f) 3114{ 3115 png p; 3116 int n,r; 3117 n = ftell(f); 3118 start_file(&p.s, f); 3119 r = parse_png_file(&p, SCAN_type,STBI_default); 3120 fseek(f,n,SEEK_SET); 3121 return r; 3122} 3123#endif 3124 3125int stbi_png_test_memory(stbi_uc const *buffer, int len) 3126{ 3127 png p; 3128 start_mem(&p.s, buffer, len); 3129 return parse_png_file(&p, SCAN_type,STBI_default); 3130} 3131 3132static int stbi_png_info_raw(png *p, int *x, int *y, int *comp) 3133{ 3134 if (!parse_png_file(p, SCAN_header, 0)) 3135 return 0; 3136 if (x) *x = p->s.img_x; 3137 if (y) *y = p->s.img_y; 3138 if (comp) *comp = p->s.img_n; 3139 return 1; 3140} 3141 3142#ifndef STBI_NO_STDIO 3143int stbi_png_info (char const *filename, int *x, int *y, int *comp) 3144{ 3145 int res; 3146 FILE *f = fopen(filename, "rb"); 3147 if (!f) return 0; 3148 res = stbi_png_info_from_file(f, x, y, comp); 3149 fclose(f); 3150 return res; 3151} 3152 3153int stbi_png_info_from_file(FILE *f, int *x, int *y, int *comp) 3154{ 3155 png p; 3156 int res; 3157 long n = ftell(f); 3158 start_file(&p.s, f); 3159 res = stbi_png_info_raw(&p, x, y, comp); 3160 fseek(f, n, SEEK_SET); 3161 return res; 3162} 3163#endif // !STBI_NO_STDIO 3164 3165int stbi_png_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) 3166{ 3167 png p; 3168 start_mem(&p.s, buffer, len); 3169 return stbi_png_info_raw(&p, x, y, comp); 3170} 3171 3172// Microsoft/Windows BMP image 3173 3174static int bmp_test(stbi *s) 3175{ 3176 int sz; 3177 if (get8(s) != 'B') return 0; 3178 if (get8(s) != 'M') return 0; 3179 get32le(s); // discard filesize 3180 get16le(s); // discard reserved 3181 get16le(s); // discard reserved 3182 get32le(s); // discard data offset 3183 sz = get32le(s); 3184 if (sz == 12 || sz == 40 || sz == 56 || sz == 108) return 1; 3185 return 0; 3186} 3187 3188#ifndef STBI_NO_STDIO 3189int stbi_bmp_test_file (FILE *f) 3190{ 3191 stbi s; 3192 int r,n = ftell(f); 3193 start_file(&s,f); 3194 r = bmp_test(&s); 3195 fseek(f,n,SEEK_SET); 3196 return r; 3197} 3198#endif 3199 3200int stbi_bmp_test_memory (stbi_uc const *buffer, int len) 3201{ 3202 stbi s; 3203 start_mem(&s, buffer, len); 3204 return bmp_test(&s); 3205} 3206 3207// returns 0..31 for the highest set bit 3208static int high_bit(unsigned int z) 3209{ 3210 int n=0; 3211 if (z == 0) return -1; 3212 if (z >= 0x10000) n += 16, z >>= 16; 3213 if (z >= 0x00100) n += 8, z >>= 8; 3214 if (z >= 0x00010) n += 4, z >>= 4; 3215 if (z >= 0x00004) n += 2, z >>= 2; 3216 if (z >= 0x00002) n += 1, z >>= 1; 3217 return n; 3218} 3219 3220static int bitcount(unsigned int a) 3221{ 3222 a = (a & 0x55555555) + ((a >> 1) & 0x55555555); // max 2 3223 a = (a & 0x33333333) + ((a >> 2) & 0x33333333); // max 4 3224 a = (a + (a >> 4)) & 0x0f0f0f0f; // max 8 per 4, now 8 bits 3225 a = (a + (a >> 8)); // max 16 per 8 bits 3226 a = (a + (a >> 16)); // max 32 per 8 bits 3227 return a & 0xff; 3228} 3229 3230static int shiftsigned(int v, int shift, int bits) 3231{ 3232 int result; 3233 int z=0; 3234 3235 if (shift < 0) v <<= -shift; 3236 else v >>= shift; 3237 result = v; 3238 3239 z = bits; 3240 while (z < 8) { 3241 result += v >> z; 3242 z += bits; 3243 } 3244 return result; 3245} 3246 3247static stbi_uc *bmp_load(stbi *s, int *x, int *y, int *comp, int req_comp) 3248{ 3249 uint8 *out; 3250 unsigned int mr=0,mg=0,mb=0,ma=0; 3251 stbi_uc pal[256][4]; 3252 int psize=0,i,j,compress=0,width; 3253 int bpp, flip_vertically, pad, target, offset, hsz; 3254 if (get8(s) != 'B' || get8(s) != 'M') return epuc("not BMP", "Corrupt BMP"); 3255 get32le(s); // discard filesize 3256 get16le(s); // discard reserved 3257 get16le(s); // discard reserved 3258 offset = get32le(s); 3259 hsz = get32le(s); 3260 if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108) return epuc("unknown BMP", "BMP type not supported: unknown"); 3261 if (hsz == 12) { 3262 s->img_x = get16le(s); 3263 s->img_y = get16le(s); 3264 } else { 3265 s->img_x = get32le(s); 3266 s->img_y = get32le(s); 3267 } 3268 if (get16le(s) != 1) return epuc("bad BMP", "bad BMP"); 3269 bpp = get16le(s); 3270 if (bpp == 1) return epuc("monochrome", "BMP type not supported: 1-bit"); 3271 flip_vertically = ((int) s->img_y) > 0; 3272 s->img_y = abs((int) s->img_y); 3273 if (hsz == 12) { 3274 if (bpp < 24) 3275 psize = (offset - 14 - 24) / 3; 3276 } else { 3277 compress = get32le(s); 3278 if (compress == 1 || compress == 2) return epuc("BMP RLE", "BMP type not supported: RLE"); 3279 get32le(s); // discard sizeof 3280 get32le(s); // discard hres 3281 get32le(s); // discard vres 3282 get32le(s); // discard colorsused 3283 get32le(s); // discard max important 3284 if (hsz == 40 || hsz == 56) { 3285 if (hsz == 56) { 3286 get32le(s); 3287 get32le(s); 3288 get32le(s); 3289 get32le(s); 3290 } 3291 if (bpp == 16 || bpp == 32) { 3292 mr = mg = mb = 0; 3293 if (compress == 0) { 3294 if (bpp == 32) { 3295 mr = 0xffu << 16; 3296 mg = 0xffu << 8; 3297 mb = 0xffu << 0; 3298 ma = 0xffu << 24; 3299 } else { 3300 mr = 31u << 10; 3301 mg = 31u << 5; 3302 mb = 31u << 0; 3303 } 3304 } else if (compress == 3) { 3305 mr = get32le(s); 3306 mg = get32le(s); 3307 mb = get32le(s); 3308 // not documented, but generated by photoshop and handled by mspaint 3309 if (mr == mg && mg == mb) { 3310 // ?!?!? 3311 return epuc("bad BMP", "bad BMP"); 3312 } 3313 } else 3314 return epuc("bad BMP", "bad BMP"); 3315 } 3316 } else { 3317 assert(hsz == 108); 3318 mr = get32le(s); 3319 mg = get32le(s); 3320 mb = get32le(s); 3321 ma = get32le(s); 3322 get32le(s); // discard color space 3323 for (i=0; i < 12; ++i) 3324 get32le(s); // discard color space parameters 3325 } 3326 if (bpp < 16) 3327 psize = (offset - 14 - hsz) >> 2; 3328 } 3329 s->img_n = ma ? 4 : 3; 3330 if (req_comp && req_comp >= 3) // we can directly decode 3 or 4 3331 target = req_comp; 3332 else 3333 target = s->img_n; // if they want monochrome, we'll post-convert 3334 out = MALLOC(target * s->img_x * s->img_y); 3335 if (!out) return epuc("outofmem", "Out of memory"); 3336 if (bpp < 16) { 3337 int z=0; 3338 if (psize == 0 || psize > 256) { FREE(out); return epuc("invalid", "Corrupt BMP"); } 3339 for (i=0; i < psize; ++i) { 3340 pal[i][2] = get8u(s); 3341 pal[i][1] = get8u(s); 3342 pal[i][0] = get8u(s); 3343 if (hsz != 12) get8(s); 3344 pal[i][3] = 255; 3345 } 3346 skip(s, offset - 14 - hsz - psize * (hsz == 12 ? 3 : 4)); 3347 if (bpp == 4) width = (s->img_x + 1) >> 1; 3348 else if (bpp == 8) width = s->img_x; 3349 else { FREE(out); return epuc("bad bpp", "Corrupt BMP"); } 3350 pad = (-width)&3; 3351 for (j=0; j < (int) s->img_y; ++j) { 3352 for (i=0; i < (int) s->img_x; i += 2) { 3353 int v=get8(s),v2=0; 3354 if (bpp == 4) { 3355 v2 = v & 15; 3356 v >>= 4; 3357 } 3358 out[z++] = pal[v][0]; 3359 out[z++] = pal[v][1]; 3360 out[z++] = pal[v][2]; 3361 if (target == 4) out[z++] = 255; 3362 if (i+1 == (int) s->img_x) break; 3363 v = (bpp == 8) ? get8(s) : v2; 3364 out[z++] = pal[v][0]; 3365 out[z++] = pal[v][1]; 3366 out[z++] = pal[v][2]; 3367 if (target == 4) out[z++] = 255; 3368 } 3369 skip(s, pad); 3370 } 3371 } else { 3372 int rshift=0,gshift=0,bshift=0,ashift=0,rcount=0,gcount=0,bcount=0,acount=0; 3373 int z = 0; 3374 int easy=0; 3375 skip(s, offset - 14 - hsz); 3376 if (bpp == 24) width = 3 * s->img_x; 3377 else if (bpp == 16) width = 2*s->img_x; 3378 else /* bpp = 32 and pad = 0 */ width=0; 3379 pad = (-width) & 3; 3380 if (bpp == 24) { 3381 easy = 1; 3382 } else if (bpp == 32) { 3383 if (mb == 0xff && mg == 0xff00 && mr == 0xff000000 && ma == 0xff000000) 3384 easy = 2; 3385 } 3386 if (!easy) { 3387 if (!mr || !mg || !mb) { 3388 FREE(out); 3389 return epuc("bad masks", "Corrupt BMP"); 3390 } 3391 // right shift amt to put high bit in position #7 3392 rshift = high_bit(mr)-7; rcount = bitcount(mr); 3393 gshift = high_bit(mg)-7; gcount = bitcount(mr); 3394 bshift = high_bit(mb)-7; bcount = bitcount(mr); 3395 ashift = high_bit(ma)-7; acount = bitcount(mr); 3396 } 3397 for (j=0; j < (int) s->img_y; ++j) { 3398 if (easy) { 3399 for (i=0; i < (int) s->img_x; ++i) { 3400 int a; 3401 out[z+2] = get8u(s); 3402 out[z+1] = get8u(s); 3403 out[z+0] = get8u(s); 3404 z += 3; 3405 a = (easy == 2 ? get8(s) : 255); 3406 if (target == 4) out[z++] = (uint8) a; 3407 } 3408 } else { 3409 for (i=0; i < (int) s->img_x; ++i) { 3410 uint32 v = (bpp == 16 ? get16le(s) : get32le(s)); 3411 int a; 3412 out[z++] = (uint8) shiftsigned(v & mr, rshift, rcount); 3413 out[z++] = (uint8) shiftsigned(v & mg, gshift, gcount); 3414 out[z++] = (uint8) shiftsigned(v & mb, bshift, bcount); 3415 a = (ma ? shiftsigned(v & ma, ashift, acount) : 255); 3416 if (target == 4) out[z++] = (uint8) a; 3417 } 3418 } 3419 skip(s, pad); 3420 } 3421 } 3422 if (flip_vertically) { 3423 stbi_uc t; 3424 for (j=0; j < (int) s->img_y>>1; ++j) { 3425 stbi_uc *p1 = out + j *s->img_x*target; 3426 stbi_uc *p2 = out + (s->img_y-1-j)*s->img_x*target; 3427 for (i=0; i < (int) s->img_x*target; ++i) { 3428 t = p1[i], p1[i] = p2[i], p2[i] = t; 3429 } 3430 } 3431 } 3432 3433 if (req_comp && req_comp != target) { 3434 out = convert_format(out, target, req_comp, s->img_x, s->img_y); 3435 if (out == NULL) return out; // convert_format frees input on failure 3436 } 3437 3438 *x = s->img_x; 3439 *y = s->img_y; 3440 if (comp) *comp = target; 3441 return out; 3442} 3443 3444#ifndef STBI_NO_STDIO 3445stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp) 3446{ 3447 stbi_uc *data; 3448 FILE *f = fopen(filename, "rb"); 3449 if (!f) return NULL; 3450 data = stbi_bmp_load_from_file(f, x,y,comp,req_comp); 3451 fclose(f); 3452 return data; 3453} 3454 3455stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp) 3456{ 3457 stbi s; 3458 start_file(&s, f); 3459 return bmp_load(&s, x,y,comp,req_comp); 3460} 3461#endif 3462 3463stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 3464{ 3465 stbi s; 3466 start_mem(&s, buffer, len); 3467 return bmp_load(&s, x,y,comp,req_comp); 3468} 3469 3470// Targa Truevision - TGA 3471// by Jonathan Dummer 3472 3473static int tga_info(stbi *s, int *x, int *y, int *comp) 3474{ 3475 int tga_w, tga_h, tga_comp; 3476 int sz; 3477 get8u(s); // discard Offset 3478 sz = get8u(s); // color type 3479 if( sz > 1 ) return 0; // only RGB or indexed allowed 3480 sz = get8u(s); // image type 3481 // only RGB or grey allowed, +/- RLE 3482 if ((sz != 1) && (sz != 2) && (sz != 3) && (sz != 9) && (sz != 10) && (sz != 11)) return 0; 3483 get16le(s); // discard palette start 3484 get16le(s); // discard palette length 3485 get8(s); // discard bits per palette color entry 3486 get16le(s); // discard x origin 3487 get16le(s); // discard y origin 3488 tga_w = get16le(s); 3489 if( tga_w < 1 ) return 0; // test width 3490 tga_h = get16le(s); 3491 if( tga_h < 1 ) return 0; // test height 3492 sz = get8(s); // bits per pixel 3493 // only RGB or RGBA or grey allowed 3494 if ((sz != 8) && (sz != 16) && (sz != 24) && (sz != 32)) return 0; 3495 tga_comp = sz; 3496 if (x) *x = tga_w; 3497 if (y) *y = tga_h; 3498 if (comp) *comp = tga_comp / 8; 3499 return 1; // seems to have passed everything 3500} 3501 3502#ifndef STBI_NO_STDIO 3503int stbi_tga_info_from_file(FILE *f, int *x, int *y, int *comp) 3504{ 3505 stbi s; 3506 int r; 3507 long n = ftell(f); 3508 start_file(&s, f); 3509 r = tga_info(&s, x, y, comp); 3510 fseek(f, n, SEEK_SET); 3511 return r; 3512} 3513#endif 3514 3515int stbi_tga_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) 3516{ 3517 stbi s; 3518 start_mem(&s, buffer, len); 3519 return tga_info(&s, x, y, comp); 3520} 3521 3522static int tga_test(stbi *s) 3523{ 3524 int sz; 3525 get8u(s); // discard Offset 3526 sz = get8u(s); // color type 3527 if ( sz > 1 ) return 0; // only RGB or indexed allowed 3528 sz = get8u(s); // image type 3529 if ( (sz != 1) && (sz != 2) && (sz != 3) && (sz != 9) && (sz != 10) && (sz != 11) ) return 0; // only RGB or grey allowed, +/- RLE 3530 get16(s); // discard palette start 3531 get16(s); // discard palette length 3532 get8(s); // discard bits per palette color entry 3533 get16(s); // discard x origin 3534 get16(s); // discard y origin 3535 if ( get16(s) < 1 ) return 0; // test width 3536 if ( get16(s) < 1 ) return 0; // test height 3537 sz = get8(s); // bits per pixel 3538 if ( (sz != 8) && (sz != 16) && (sz != 24) && (sz != 32) ) return 0; // only RGB or RGBA or grey allowed 3539 return 1; // seems to have passed everything 3540} 3541 3542#ifndef STBI_NO_STDIO 3543int stbi_tga_test_file (FILE *f) 3544{ 3545 stbi s; 3546 int r,n = ftell(f); 3547 start_file(&s, f); 3548 r = tga_test(&s); 3549 fseek(f,n,SEEK_SET); 3550 return r; 3551} 3552#endif 3553 3554int stbi_tga_test_memory (stbi_uc const *buffer, int len) 3555{ 3556 stbi s; 3557 start_mem(&s, buffer, len); 3558 return tga_test(&s); 3559} 3560 3561static stbi_uc *tga_load(stbi *s, int *x, int *y, int *comp, int req_comp) 3562{ 3563 // read in the TGA header stuff 3564 int tga_offset = get8u(s); 3565 int tga_indexed = get8u(s); 3566 int tga_image_type = get8u(s); 3567 int tga_is_RLE = 0; 3568 int tga_palette_start = get16le(s); 3569 int tga_palette_len = get16le(s); 3570 int tga_palette_bits = get8u(s); 3571 int tga_x_origin = get16le(s); 3572 int tga_y_origin = get16le(s); 3573 int tga_width = get16le(s); 3574 int tga_height = get16le(s); 3575 int tga_bits_per_pixel = get8u(s); 3576 int tga_inverted = get8u(s); 3577 // image data 3578 unsigned char *tga_data; 3579 unsigned char *tga_palette = NULL; 3580 int i, j; 3581 unsigned char raw_data[4]; 3582 unsigned char trans_data[4]; 3583 int RLE_count = 0; 3584 int RLE_repeating = 0; 3585 int read_next_pixel = 1; 3586 3587 // do a tiny bit of precessing 3588 if ( tga_image_type >= 8 ) 3589 { 3590 tga_image_type -= 8; 3591 tga_is_RLE = 1; 3592 } 3593 /* int tga_alpha_bits = tga_inverted & 15; */ 3594 tga_inverted = 1 - ((tga_inverted >> 5) & 1); 3595 3596 // error check 3597 if ( //(tga_indexed) || 3598 (tga_width < 1) || (tga_height < 1) || 3599 (tga_image_type < 1) || (tga_image_type > 3) || 3600 ((tga_bits_per_pixel != 8) && (tga_bits_per_pixel != 16) && 3601 (tga_bits_per_pixel != 24) && (tga_bits_per_pixel != 32)) 3602 ) 3603 { 3604 return NULL; 3605 } 3606 3607 // If I'm paletted, then I'll use the number of bits from the palette 3608 if ( tga_indexed ) 3609 { 3610 tga_bits_per_pixel = tga_palette_bits; 3611 } 3612 3613 // tga info 3614 *x = tga_width; 3615 *y = tga_height; 3616 if ( (req_comp < 1) || (req_comp > 4) ) 3617 { 3618 // just use whatever the file was 3619 req_comp = tga_bits_per_pixel / 8; 3620 *comp = req_comp; 3621 } else 3622 { 3623 // force a new number of components 3624 *comp = tga_bits_per_pixel/8; 3625 } 3626 tga_data = MALLOC( tga_width * tga_height * req_comp ); 3627 3628 // skip to the data's starting position (offset usually = 0) 3629 skip(s, tga_offset ); 3630 // do I need to load a palette? 3631 if ( tga_indexed ) 3632 { 3633 // any data to skip? (offset usually = 0) 3634 skip(s, tga_palette_start ); 3635 // load the palette 3636 tga_palette = MALLOC( tga_palette_len * tga_palette_bits / 8 ); 3637 if (!getn(s, tga_palette, tga_palette_len * tga_palette_bits / 8 )) 3638 return NULL; 3639 } 3640 // load the data 3641 trans_data[0] = trans_data[1] = trans_data[2] = trans_data[3] = 0; 3642 for (i=0; i < tga_width * tga_height; ++i) 3643 { 3644 // if I'm in RLE mode, do I need to get a RLE chunk? 3645 if ( tga_is_RLE ) 3646 { 3647 if ( RLE_count == 0 ) 3648 { 3649 // yep, get the next byte as a RLE command 3650 int RLE_cmd = get8u(s); 3651 RLE_count = 1 + (RLE_cmd & 127); 3652 RLE_repeating = RLE_cmd >> 7; 3653 read_next_pixel = 1; 3654 } else if ( !RLE_repeating ) 3655 { 3656 read_next_pixel = 1; 3657 } 3658 } else 3659 { 3660 read_next_pixel = 1; 3661 } 3662 // OK, if I need to read a pixel, do it now 3663 if ( read_next_pixel ) 3664 { 3665 // load however much data we did have 3666 if ( tga_indexed ) 3667 { 3668 // read in 1 byte, then perform the lookup 3669 int pal_idx = get8u(s); 3670 if ( pal_idx >= tga_palette_len ) 3671 { 3672 // invalid index 3673 pal_idx = 0; 3674 } 3675 pal_idx *= tga_bits_per_pixel / 8; 3676 for (j = 0; j*8 < tga_bits_per_pixel; ++j) 3677 { 3678 raw_data[j] = tga_palette[pal_idx+j]; 3679 } 3680 } else 3681 { 3682 // read in the data raw 3683 for (j = 0; j*8 < tga_bits_per_pixel; ++j) 3684 { 3685 raw_data[j] = get8u(s); 3686 } 3687 } 3688 // convert raw to the intermediate format 3689 switch (tga_bits_per_pixel) 3690 { 3691 case 8: 3692 // Luminous => RGBA 3693 trans_data[0] = raw_data[0]; 3694 trans_data[1] = raw_data[0]; 3695 trans_data[2] = raw_data[0]; 3696 trans_data[3] = 255; 3697 break; 3698 case 16: 3699 // Luminous,Alpha => RGBA 3700 trans_data[0] = raw_data[0]; 3701 trans_data[1] = raw_data[0]; 3702 trans_data[2] = raw_data[0]; 3703 trans_data[3] = raw_data[1]; 3704 break; 3705 case 24: 3706 // BGR => RGBA 3707 trans_data[0] = raw_data[2]; 3708 trans_data[1] = raw_data[1]; 3709 trans_data[2] = raw_data[0]; 3710 trans_data[3] = 255; 3711 break; 3712 case 32: 3713 // BGRA => RGBA 3714 trans_data[0] = raw_data[2]; 3715 trans_data[1] = raw_data[1]; 3716 trans_data[2] = raw_data[0]; 3717 trans_data[3] = raw_data[3]; 3718 break; 3719 } 3720 // clear the reading flag for the next pixel 3721 read_next_pixel = 0; 3722 } // end of reading a pixel 3723 // convert to final format 3724 switch (req_comp) 3725 { 3726 case 1: 3727 // RGBA => Luminance 3728 tga_data[i*req_comp+0] = compute_y(trans_data[0],trans_data[1],trans_data[2]); 3729 break; 3730 case 2: 3731 // RGBA => Luminance,Alpha 3732 tga_data[i*req_comp+0] = compute_y(trans_data[0],trans_data[1],trans_data[2]); 3733 tga_data[i*req_comp+1] = trans_data[3]; 3734 break; 3735 case 3: 3736 // RGBA => RGB 3737 tga_data[i*req_comp+0] = trans_data[0]; 3738 tga_data[i*req_comp+1] = trans_data[1]; 3739 tga_data[i*req_comp+2] = trans_data[2]; 3740 break; 3741 case 4: 3742 // RGBA => RGBA 3743 tga_data[i*req_comp+0] = trans_data[0]; 3744 tga_data[i*req_comp+1] = trans_data[1]; 3745 tga_data[i*req_comp+2] = trans_data[2]; 3746 tga_data[i*req_comp+3] = trans_data[3]; 3747 break; 3748 } 3749 // in case we're in RLE mode, keep counting down 3750 --RLE_count; 3751 } 3752 // do I need to invert the image? 3753 if ( tga_inverted ) 3754 { 3755 for (j = 0; j*2 < tga_height; ++j) 3756 { 3757 int index1 = j * tga_width * req_comp; 3758 int index2 = (tga_height - 1 - j) * tga_width * req_comp; 3759 for (i = tga_width * req_comp; i > 0; --i) 3760 { 3761 unsigned char temp = tga_data[index1]; 3762 tga_data[index1] = tga_data[index2]; 3763 tga_data[index2] = temp; 3764 ++index1; 3765 ++index2; 3766 } 3767 } 3768 } 3769 // clear my palette, if I had one 3770 if ( tga_palette != NULL ) 3771 { 3772 FREE( tga_palette ); 3773 } 3774 // the things I do to get rid of an error message, and yet keep 3775 // Microsoft's C compilers happy... [8^( 3776 tga_palette_start = tga_palette_len = tga_palette_bits = 3777 tga_x_origin = tga_y_origin = 0; 3778 // OK, done 3779 return tga_data; 3780} 3781 3782#ifndef STBI_NO_STDIO 3783stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp) 3784{ 3785 stbi_uc *data; 3786 FILE *f = fopen(filename, "rb"); 3787 if (!f) return NULL; 3788 data = stbi_tga_load_from_file(f, x,y,comp,req_comp); 3789 fclose(f); 3790 return data; 3791} 3792 3793stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp) 3794{ 3795 stbi s; 3796 start_file(&s, f); 3797 return tga_load(&s, x,y,comp,req_comp); 3798} 3799#endif 3800 3801stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 3802{ 3803 stbi s; 3804 start_mem(&s, buffer, len); 3805 return tga_load(&s, x,y,comp,req_comp); 3806} 3807 3808 3809// ************************************************************************************************* 3810// Photoshop PSD loader -- PD by Thatcher Ulrich, integration by Nicolas Schulz, tweaked by STB 3811 3812static int psd_test(stbi *s) 3813{ 3814 if (get32(s) != 0x38425053) return 0; // "8BPS" 3815 else return 1; 3816} 3817 3818#ifndef STBI_NO_STDIO 3819int stbi_psd_test_file(FILE *f) 3820{ 3821 stbi s; 3822 int r,n = ftell(f); 3823 start_file(&s, f); 3824 r = psd_test(&s); 3825 fseek(f,n,SEEK_SET); 3826 return r; 3827} 3828#endif 3829 3830int stbi_psd_test_memory(stbi_uc const *buffer, int len) 3831{ 3832 stbi s; 3833 start_mem(&s, buffer, len); 3834 return psd_test(&s); 3835} 3836 3837static stbi_uc *psd_load(stbi *s, int *x, int *y, int *comp, int req_comp) 3838{ 3839 int pixelCount; 3840 int channelCount, compression; 3841 int channel, i, count, len; 3842 int w,h; 3843 uint8 *out; 3844 3845 // Check identifier 3846 if (get32(s) != 0x38425053) // "8BPS" 3847 return epuc("not PSD", "Corrupt PSD image"); 3848 3849 // Check file type version. 3850 if (get16(s) != 1) 3851 return epuc("wrong version", "Unsupported version of PSD image"); 3852 3853 // Skip 6 reserved bytes. 3854 skip(s, 6 ); 3855 3856 // Read the number of channels (R, G, B, A, etc). 3857 channelCount = get16(s); 3858 if (channelCount < 0 || channelCount > 16) 3859 return epuc("wrong channel count", "Unsupported number of channels in PSD image"); 3860 3861 // Read the rows and columns of the image. 3862 h = get32(s); 3863 w = get32(s); 3864 3865 // Make sure the depth is 8 bits. 3866 if (get16(s) != 8) 3867 return epuc("unsupported bit depth", "PSD bit depth is not 8 bit"); 3868 3869 // Make sure the color mode is RGB. 3870 // Valid options are: 3871 // 0: Bitmap 3872 // 1: Grayscale 3873 // 2: Indexed color 3874 // 3: RGB color 3875 // 4: CMYK color 3876 // 7: Multichannel 3877 // 8: Duotone 3878 // 9: Lab color 3879 if (get16(s) != 3) 3880 return epuc("wrong color format", "PSD is not in RGB color format"); 3881 3882 // Skip the Mode Data. (It's the palette for indexed color; other info for other modes.) 3883 skip(s,get32(s) ); 3884 3885 // Skip the image resources. (resolution, pen tool paths, etc) 3886 skip(s, get32(s) ); 3887 3888 // Skip the reserved data. 3889 skip(s, get32(s) ); 3890 3891 // Find out if the data is compressed. 3892 // Known values: 3893 // 0: no compression 3894 // 1: RLE compressed 3895 compression = get16(s); 3896 if (compression > 1) 3897 return epuc("bad compression", "PSD has an unknown compression format"); 3898 3899 // Create the destination image. 3900 out = MALLOC(4 * w*h); 3901 if (!out) return epuc("outofmem", "Out of memory"); 3902 pixelCount = w*h; 3903 3904 // Initialize the data to zero. 3905 //memset( out, 0, pixelCount * 4 ); 3906 3907 // Finally, the image data. 3908 if (compression) { 3909 // RLE as used by .PSD and .TIFF 3910 // Loop until you get the number of unpacked bytes you are expecting: 3911 // Read the next source byte into n. 3912 // If n is between 0 and 127 inclusive, copy the next n+1 bytes literally. 3913 // Else if n is between -127 and -1 inclusive, copy the next byte -n+1 times. 3914 // Else if n is 128, noop. 3915 // Endloop 3916 3917 // The RLE-compressed data is preceded by a 2-byte data count for each row in the data, 3918 // which we're going to just skip. 3919 skip(s, h * channelCount * 2 ); 3920 3921 // Read the RLE data by channel. 3922 for (channel = 0; channel < 4; channel++) { 3923 uint8 *p; 3924 3925 p = out+channel; 3926 if (channel >= channelCount) { 3927 // Fill this channel with default data. 3928 for (i = 0; i < pixelCount; i++) *p = (channel == 3 ? 255 : 0), p += 4; 3929 } else { 3930 // Read the RLE data. 3931 count = 0; 3932 while (count < pixelCount) { 3933 len = get8(s); 3934 if (len == 128) { 3935 // No-op. 3936 } else if (len < 128) { 3937 // Copy next len+1 bytes literally. 3938 len++; 3939 count += len; 3940 while (len) { 3941 *p = get8u(s); 3942 p += 4; 3943 len--; 3944 } 3945 } else if (len > 128) { 3946 uint8 val; 3947 // Next -len+1 bytes in the dest are replicated from next source byte. 3948 // (Interpret len as a negative 8-bit int.) 3949 len ^= 0x0FF; 3950 len += 2; 3951 val = get8u(s); 3952 count += len; 3953 while (len) { 3954 *p = val; 3955 p += 4; 3956 len--; 3957 } 3958 } 3959 } 3960 } 3961 } 3962 3963 } else { 3964 // We're at the raw image data. It's each channel in order (Red, Green, Blue, Alpha, ...) 3965 // where each channel consists of an 8-bit value for each pixel in the image. 3966 3967 // Read the data by channel. 3968 for (channel = 0; channel < 4; channel++) { 3969 uint8 *p; 3970 3971 p = out + channel; 3972 if (channel > channelCount) { 3973 // Fill this channel with default data. 3974 for (i = 0; i < pixelCount; i++) *p = channel == 3 ? 255 : 0, p += 4; 3975 } else { 3976 // Read the data. 3977 for (i = 0; i < pixelCount; i++) 3978 *p = get8u(s), p += 4; 3979 } 3980 } 3981 } 3982 3983 if (req_comp && req_comp != 4) { 3984 out = convert_format(out, 4, req_comp, w, h); 3985 if (out == NULL) return out; // convert_format frees input on failure 3986 } 3987 3988 if (comp) *comp = channelCount; 3989 *y = h; 3990 *x = w; 3991 3992 return out; 3993} 3994 3995#ifndef STBI_NO_STDIO 3996stbi_uc *stbi_psd_load(char const *filename, int *x, int *y, int *comp, int req_comp) 3997{ 3998 stbi_uc *data; 3999 FILE *f = fopen(filename, "rb"); 4000 if (!f) return NULL; 4001 data = stbi_psd_load_from_file(f, x,y,comp,req_comp); 4002 fclose(f); 4003 return data; 4004} 4005 4006stbi_uc *stbi_psd_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 4007{ 4008 stbi s; 4009 start_file(&s, f); 4010 return psd_load(&s, x,y,comp,req_comp); 4011} 4012#endif 4013 4014stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 4015{ 4016 stbi s; 4017 start_mem(&s, buffer, len); 4018 return psd_load(&s, x,y,comp,req_comp); 4019} 4020 4021// ************************************************************************************************* 4022// Softimage PIC loader 4023// by Tom Seddon 4024// 4025// See http://softimage.wiki.softimage.com/index.php/INFO:_PIC_file_format 4026// See http://ozviz.wasp.uwa.edu.au/~pbourke/dataformats/softimagepic/ 4027 4028static int pic_is4(stbi *s,const char *str) 4029{ 4030 int i; 4031 for (i=0; i<4; ++i) 4032 if (get8(s) != (stbi_uc)str[i]) 4033 return 0; 4034 4035 return 1; 4036} 4037 4038static int pic_test(stbi *s) 4039{ 4040 int i; 4041 4042 if (!pic_is4(s,"\x53\x80\xF6\x34")) 4043 return 0; 4044 4045 for(i=0;i<84;++i) 4046 get8(s); 4047 4048 if (!pic_is4(s,"PICT")) 4049 return 0; 4050 4051 return 1; 4052} 4053 4054typedef struct 4055{ 4056 stbi_uc size,type,channel; 4057} pic_packet_t; 4058 4059static stbi_uc *pic_readval(stbi *s, int channel, stbi_uc *dest) 4060{ 4061 int mask=0x80, i; 4062 4063 for (i=0; i<4; ++i, mask>>=1) { 4064 if (channel & mask) { 4065 if (at_eof(s)) return epuc("bad file","PIC file too short"); 4066 dest[i]=get8u(s); 4067 } 4068 } 4069 4070 return dest; 4071} 4072 4073static void pic_copyval(int channel,stbi_uc *dest,const stbi_uc *src) 4074{ 4075 int mask=0x80,i; 4076 4077 for (i=0;i<4; ++i, mask>>=1) 4078 if (channel&mask) 4079 dest[i]=src[i]; 4080} 4081 4082static stbi_uc *pic_load2(stbi *s,int width,int height,int *comp, stbi_uc *result) 4083{ 4084 int act_comp=0,num_packets=0,y,chained; 4085 pic_packet_t packets[10]; 4086 4087 // this will (should...) cater for even some bizarre stuff like having data 4088 // for the same channel in multiple packets. 4089 do { 4090 pic_packet_t *packet; 4091 4092 if (num_packets==sizeof(packets)/sizeof(packets[0])) 4093 return epuc("bad format","too many packets"); 4094 4095 packet = &packets[num_packets++]; 4096 4097 chained = get8(s); 4098 packet->size = get8u(s); 4099 packet->type = get8u(s); 4100 packet->channel = get8u(s); 4101 4102 act_comp |= packet->channel; 4103 4104 if (at_eof(s)) return epuc("bad file","file too short (reading packets)"); 4105 if (packet->size != 8) return epuc("bad format","packet isn't 8bpp"); 4106 } while (chained); 4107 4108 *comp = (act_comp & 0x10 ? 4 : 3); // has alpha channel? 4109 4110 for(y=0; y<height; ++y) { 4111 int packet_idx; 4112 4113 for(packet_idx=0; packet_idx < num_packets; ++packet_idx) { 4114 pic_packet_t *packet = &packets[packet_idx]; 4115 stbi_uc *dest = result+y*width*4; 4116 4117 switch (packet->type) { 4118 default: 4119 return epuc("bad format","packet has bad compression type"); 4120 4121 case 0: {//uncompressed 4122 int x; 4123 4124 for(x=0;x<width;++x, dest+=4) 4125 if (!pic_readval(s,packet->channel,dest)) 4126 return 0; 4127 break; 4128 } 4129 4130 case 1://Pure RLE 4131 { 4132 int left=width, i; 4133 4134 while (left>0) { 4135 stbi_uc count,value[4]; 4136 4137 count=get8u(s); 4138 if (at_eof(s)) return epuc("bad file","file too short (pure read count)"); 4139 4140 if (count > left) 4141 count = (uint8) left; 4142 4143 if (!pic_readval(s,packet->channel,value)) return 0; 4144 4145 for(i=0; i<count; ++i,dest+=4) 4146 pic_copyval(packet->channel,dest,value); 4147 left -= count; 4148 } 4149 } 4150 break; 4151 4152 case 2: {//Mixed RLE 4153 int left=width; 4154 while (left>0) { 4155 int count = get8(s), i; 4156 if (at_eof(s)) return epuc("bad file","file too short (mixed read count)"); 4157 4158 if (count >= 128) { // Repeated 4159 stbi_uc value[4]; 4160 4161 if (count==128) 4162 count = get16(s); 4163 else 4164 count -= 127; 4165 if (count > left) 4166 return epuc("bad file","scanline overrun"); 4167 4168 if (!pic_readval(s,packet->channel,value)) 4169 return 0; 4170 4171 for(i=0;i<count;++i, dest += 4) 4172 pic_copyval(packet->channel,dest,value); 4173 } else { // Raw 4174 ++count; 4175 if (count>left) return epuc("bad file","scanline overrun"); 4176 4177 for(i=0;i<count;++i, dest+=4) 4178 if (!pic_readval(s,packet->channel,dest)) 4179 return 0; 4180 } 4181 left-=count; 4182 } 4183 break; 4184 } 4185 } 4186 } 4187 } 4188 4189 return result; 4190} 4191 4192static stbi_uc *pic_load(stbi *s,int *px,int *py,int *comp,int req_comp) 4193{ 4194 stbi_uc *result; 4195 int i, x,y; 4196 4197 for (i=0; i<92; ++i) 4198 get8(s); 4199 4200 x = get16(s); 4201 y = get16(s); 4202 if (at_eof(s)) return epuc("bad file","file too short (pic header)"); 4203 if ((1 << 28) / x < y) return epuc("too large", "Image too large to decode"); 4204 4205 get32(s); //skip `ratio' 4206 get16(s); //skip `fields' 4207 get16(s); //skip `pad' 4208 4209 // intermediate buffer is RGBA 4210 result = MALLOC(x*y*4); 4211 memset(result, 0xff, x*y*4); 4212 4213 if (!pic_load2(s,x,y,comp, result)) { 4214 FREE(result); 4215 result=0; 4216 } 4217 *px = x; 4218 *py = y; 4219 if (req_comp == 0) req_comp = *comp; 4220 result=convert_format(result,4,req_comp,x,y); 4221 4222 return result; 4223} 4224 4225int stbi_pic_test_memory(stbi_uc const *buffer, int len) 4226{ 4227 stbi s; 4228 start_mem(&s,buffer,len); 4229 return pic_test(&s); 4230} 4231 4232stbi_uc *stbi_pic_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 4233{ 4234 stbi s; 4235 start_mem(&s,buffer,len); 4236 return pic_load(&s,x,y,comp,req_comp); 4237} 4238 4239#ifndef STBI_NO_STDIO 4240int stbi_pic_test_file(FILE *f) 4241{ 4242 int result; 4243 long l = ftell(f); 4244 stbi s; 4245 start_file(&s,f); 4246 result = pic_test(&s); 4247 fseek(f,l,SEEK_SET); 4248 return result; 4249} 4250 4251stbi_uc *stbi_pic_load(char const *filename,int *x, int *y, int *comp, int req_comp) 4252{ 4253 stbi_uc *result; 4254 FILE *f=fopen(filename,"rb"); 4255 if (!f) return 0; 4256 result = stbi_pic_load_from_file(f,x,y,comp,req_comp); 4257 fclose(f); 4258 return result; 4259} 4260 4261stbi_uc *stbi_pic_load_from_file(FILE *f,int *x, int *y, int *comp, int req_comp) 4262{ 4263 stbi s; 4264 start_file(&s,f); 4265 return pic_load(&s,x,y,comp,req_comp); 4266} 4267#endif 4268 4269// ************************************************************************************************* 4270// GIF loader -- public domain by Jean-Marc Lienher -- simplified/shrunk by stb 4271typedef struct stbi_gif_lzw_struct { 4272 int16 prefix; 4273 uint8 first; 4274 uint8 suffix; 4275} stbi_gif_lzw; 4276 4277typedef struct stbi_gif_struct 4278{ 4279 int w,h; 4280 stbi_uc *out; // output buffer (always 4 components) 4281 int flags, bgindex, ratio, transparent, eflags; 4282 uint8 pal[256][4]; 4283 uint8 lpal[256][4]; 4284 stbi_gif_lzw codes[4096]; 4285 uint8 *color_table; 4286 int parse, step; 4287 int lflags; 4288 int start_x, start_y; 4289 int max_x, max_y; 4290 int cur_x, cur_y; 4291 int line_size; 4292} stbi_gif; 4293 4294static int gif_test(stbi *s) 4295{ 4296 int sz; 4297 if (get8(s) != 'G' || get8(s) != 'I' || get8(s) != 'F' || get8(s) != '8') return 0; 4298 sz = get8(s); 4299 if (sz != '9' && sz != '7') return 0; 4300 if (get8(s) != 'a') return 0; 4301 return 1; 4302} 4303 4304#ifndef STBI_NO_STDIO 4305int stbi_gif_test_file (FILE *f) 4306{ 4307 stbi s; 4308 int r,n = ftell(f); 4309 start_file(&s,f); 4310 r = gif_test(&s); 4311 fseek(f,n,SEEK_SET); 4312 return r; 4313} 4314#endif 4315 4316int stbi_gif_test_memory (stbi_uc const *buffer, int len) 4317{ 4318 stbi s; 4319 start_mem(&s, buffer, len); 4320 return gif_test(&s); 4321} 4322 4323static void stbi_gif_parse_colortable(stbi *s, uint8 pal[256][4], int num_entries, int transp) 4324{ 4325 int i; 4326 for (i=0; i < num_entries; ++i) { 4327 pal[i][2] = get8u(s); 4328 pal[i][1] = get8u(s); 4329 pal[i][0] = get8u(s); 4330 pal[i][3] = transp ? 0 : 255; 4331 } 4332} 4333 4334static int stbi_gif_header(stbi *s, stbi_gif *g, int *comp, int is_info) 4335{ 4336 uint8 ver; 4337 if (get8(s) != 'G' || get8(s) != 'I' || get8(s) != 'F' || get8(s) != '8') 4338 return e("not GIF", "Corrupt GIF"); 4339 4340 ver = get8u(s); 4341 if (ver != '7' && ver != '9') return e("not GIF", "Corrupt GIF"); 4342 if (get8(s) != 'a') return e("not GIF", "Corrupt GIF"); 4343 4344 failure_reason = ""; 4345 g->w = get16le(s); 4346 g->h = get16le(s); 4347 g->flags = get8(s); 4348 g->bgindex = get8(s); 4349 g->ratio = get8(s); 4350 g->transparent = -1; 4351 4352 if (comp != 0) *comp = 4; // can't actually tell whether it's 3 or 4 until we parse the comments 4353 4354 if (is_info) return 1; 4355 4356 if (g->flags & 0x80) 4357 stbi_gif_parse_colortable(s,g->pal, 2 << (g->flags & 7), -1); 4358 4359 return 1; 4360} 4361 4362static int stbi_gif_info_raw(stbi *s, int *x, int *y, int *comp) 4363{ 4364 stbi_gif g; 4365 if (!stbi_gif_header(s, &g, comp, 1)) return 0; 4366 if (x) *x = g.w; 4367 if (y) *y = g.h; 4368 return 1; 4369} 4370 4371static void stbi_out_gif_code(stbi_gif *g, uint16 code) 4372{ 4373 uint8 *p, *c; 4374 4375 // recurse to decode the prefixes, since the linked-list is backwards, 4376 // and working backwards through an interleaved image would be nasty 4377 if (g->codes[code].prefix >= 0) 4378 stbi_out_gif_code(g, g->codes[code].prefix); 4379 4380 if (g->cur_y >= g->max_y) return; 4381 4382 p = &g->out[g->cur_x + g->cur_y]; 4383 c = &g->color_table[g->codes[code].suffix * 4]; 4384 4385 if (c[3] >= 128) { 4386 p[0] = c[2]; 4387 p[1] = c[1]; 4388 p[2] = c[0]; 4389 p[3] = c[3]; 4390 } 4391 g->cur_x += 4; 4392 4393 if (g->cur_x >= g->max_x) { 4394 g->cur_x = g->start_x; 4395 g->cur_y += g->step; 4396 4397 while (g->cur_y >= g->max_y && g->parse > 0) { 4398 g->step = (1 << g->parse) * g->line_size; 4399 g->cur_y = g->start_y + (g->step >> 1); 4400 --g->parse; 4401 } 4402 } 4403} 4404 4405static uint8 *stbi_process_gif_raster(stbi *s, stbi_gif *g) 4406{ 4407 uint8 lzw_cs; 4408 int32 len, code; 4409 uint32 first; 4410 int32 codesize, codemask, avail, oldcode, bits, valid_bits, clear; 4411 stbi_gif_lzw *p; 4412 4413 lzw_cs = get8u(s); 4414 clear = 1 << lzw_cs; 4415 first = 1; 4416 codesize = lzw_cs + 1; 4417 codemask = (1 << codesize) - 1; 4418 bits = 0; 4419 valid_bits = 0; 4420 for (code = 0; code < clear; code++) { 4421 g->codes[code].prefix = -1; 4422 g->codes[code].first = (uint8) code; 4423 g->codes[code].suffix = (uint8) code; 4424 } 4425 4426 // support no starting clear code 4427 avail = clear+2; 4428 oldcode = -1; 4429 4430 len = 0; 4431 for(;;) { 4432 if (valid_bits < codesize) { 4433 if (len == 0) { 4434 len = get8(s); // start new block 4435 if (len == 0) 4436 return g->out; 4437 } 4438 --len; 4439 bits |= (int32) get8(s) << valid_bits; 4440 valid_bits += 8; 4441 } else { 4442 code = bits & codemask; 4443 bits >>= codesize; 4444 valid_bits -= codesize; 4445 // @OPTIMIZE: is there some way we can accelerate the non-clear path? 4446 if (code == clear) { // clear code 4447 codesize = lzw_cs + 1; 4448 codemask = (1 << codesize) - 1; 4449 avail = clear + 2; 4450 oldcode = -1; 4451 first = 0; 4452 } else if (code == clear + 1) { // end of stream code 4453 skip(s, len); 4454 while ((len = get8(s)) > 0) 4455 skip(s,len); 4456 return g->out; 4457 } else if (code <= avail) { 4458 if (first) return epuc("no clear code", "Corrupt GIF"); 4459 4460 if (oldcode >= 0) { 4461 p = &g->codes[avail++]; 4462 if (avail > 4096) return epuc("too many codes", "Corrupt GIF"); 4463 p->prefix = (int16) oldcode; 4464 p->first = g->codes[oldcode].first; 4465 p->suffix = (code == avail) ? p->first : g->codes[code].first; 4466 } else if (code == avail) 4467 return epuc("illegal code in raster", "Corrupt GIF"); 4468 4469 stbi_out_gif_code(g, (uint16) code); 4470 4471 if ((avail & codemask) == 0 && avail <= 0x0FFF) { 4472 codesize++; 4473 codemask = (1 << codesize) - 1; 4474 } 4475 4476 oldcode = code; 4477 } else { 4478 return epuc("illegal code in raster", "Corrupt GIF"); 4479 } 4480 } 4481 } 4482} 4483 4484static void stbi_fill_gif_background(stbi_gif *g) 4485{ 4486 int i; 4487 uint8 *c = g->pal[g->bgindex]; 4488 // @OPTIMIZE: write a dword at a time 4489 for (i = 0; i < g->w * g->h * 4; i += 4) { 4490 uint8 *p = &g->out[i]; 4491 p[0] = c[2]; 4492 p[1] = c[1]; 4493 p[2] = c[0]; 4494 p[3] = c[3]; 4495 } 4496} 4497 4498// this function is designed to support animated gifs, although stb_image doesn't support it 4499static uint8 *stbi_gif_load_next(stbi *s, stbi_gif *g, int *comp, int req_comp) 4500{ 4501 int i; 4502 uint8 *old_out = 0; 4503 4504 if (g->out == 0) { 4505 if (!stbi_gif_header(s, g, comp,0)) return 0; // failure_reason set by stbi_gif_header 4506 g->out = MALLOC(4 * g->w * g->h); 4507 if (g->out == 0) return epuc("outofmem", "Out of memory"); 4508 stbi_fill_gif_background(g); 4509 } else { 4510 // animated-gif-only path 4511 if (((g->eflags & 0x1C) >> 2) == 3) { 4512 old_out = g->out; 4513 g->out = MALLOC(4 * g->w * g->h); 4514 if (g->out == 0) return epuc("outofmem", "Out of memory"); 4515 memcpy(g->out, old_out, g->w*g->h*4); 4516 } 4517 } 4518 4519 for (;;) { 4520 switch (get8(s)) { 4521 case 0x2C: /* Image Descriptor */ 4522 { 4523 int32 x, y, w, h; 4524 uint8 *o; 4525 4526 x = get16le(s); 4527 y = get16le(s); 4528 w = get16le(s); 4529 h = get16le(s); 4530 if (((x + w) > (g->w)) || ((y + h) > (g->h))) 4531 return epuc("bad Image Descriptor", "Corrupt GIF"); 4532 4533 g->line_size = g->w * 4; 4534 g->start_x = x * 4; 4535 g->start_y = y * g->line_size; 4536 g->max_x = g->start_x + w * 4; 4537 g->max_y = g->start_y + h * g->line_size; 4538 g->cur_x = g->start_x; 4539 g->cur_y = g->start_y; 4540 4541 g->lflags = get8(s); 4542 4543 if (g->lflags & 0x40) { 4544 g->step = 8 * g->line_size; // first interlaced spacing 4545 g->parse = 3; 4546 } else { 4547 g->step = g->line_size; 4548 g->parse = 0; 4549 } 4550 4551 if (g->lflags & 0x80) { 4552 stbi_gif_parse_colortable(s,g->lpal, 2 << (g->lflags & 7), g->eflags & 0x01 ? g->transparent : -1); 4553 g->color_table = (uint8 *) g->lpal; 4554 } else if (g->flags & 0x80) { 4555 for (i=0; i < 256; ++i) // @OPTIMIZE: reset only the previous transparent 4556 g->pal[i][3] = 255; 4557 if (g->transparent >= 0 && (g->eflags & 0x01)) 4558 g->pal[g->transparent][3] = 0; 4559 g->color_table = (uint8 *) g->pal; 4560 } else 4561 return epuc("missing color table", "Corrupt GIF"); 4562 4563 o = stbi_process_gif_raster(s, g); 4564 if (o == NULL) return NULL; 4565 4566 if (req_comp && req_comp != 4) 4567 o = convert_format(o, 4, req_comp, g->w, g->h); 4568 return o; 4569 } 4570 4571 case 0x21: // Comment Extension. 4572 { 4573 int len; 4574 if (get8(s) == 0xF9) { // Graphic Control Extension. 4575 len = get8(s); 4576 if (len == 4) { 4577 g->eflags = get8(s); 4578 get16le(s); // delay 4579 g->transparent = get8(s); 4580 } else { 4581 skip(s, len); 4582 break; 4583 } 4584 } 4585 while ((len = get8(s)) != 0) 4586 skip(s, len); 4587 break; 4588 } 4589 4590 case 0x3B: // gif stream termination code 4591 return (uint8 *) 1; 4592 4593 default: 4594 return epuc("unknown code", "Corrupt GIF"); 4595 } 4596 } 4597} 4598 4599#ifndef STBI_NO_STDIO 4600stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp) 4601{ 4602 uint8 *data; 4603 FILE *f = fopen(filename, "rb"); 4604 if (!f) return NULL; 4605 data = stbi_gif_load_from_file(f, x,y,comp,req_comp); 4606 fclose(f); 4607 return data; 4608} 4609 4610stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp) 4611{ 4612 uint8 *u = 0; 4613 stbi s; 4614 stbi_gif g={0}; 4615 start_file(&s, f); 4616 4617 u = stbi_gif_load_next(&s, &g, comp, req_comp); 4618 if (u == (void *) 1) u = 0; // end of animated gif marker 4619 if (u) { 4620 *x = g.w; 4621 *y = g.h; 4622 } 4623 4624 return u; 4625} 4626#endif 4627 4628stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 4629{ 4630 uint8 *u = 0; 4631 stbi s; 4632 stbi_gif *pg; 4633 4634 #ifdef STBI_SMALL_STACK 4635 pg = MALLOC(sizeof(*pg)); 4636 if (pg == NULL) 4637 return NULL; 4638 #else 4639 stbi_gif g; 4640 pg = &g; 4641 #endif 4642 4643 memset(pg, 0, sizeof(*pg)); 4644 start_mem(&s, buffer, len); 4645 u = stbi_gif_load_next(&s, pg, comp, req_comp); 4646 if (u == (void *) 1) u = 0; // end of animated gif marker 4647 if (u) { 4648 *x = pg->w; 4649 *y = pg->h; 4650 } 4651 4652 #ifdef STBI_SMALL_STACK 4653 FREE(pg); 4654 #endif 4655 4656 return u; 4657} 4658 4659#ifndef STBI_NO_STDIO 4660int stbi_gif_info (char const *filename, int *x, int *y, int *comp) 4661{ 4662 int res; 4663 FILE *f = fopen(filename, "rb"); 4664 if (!f) return 0; 4665 res = stbi_gif_info_from_file(f, x, y, comp); 4666 fclose(f); 4667 return res; 4668} 4669 4670int stbi_gif_info_from_file(FILE *f, int *x, int *y, int *comp) 4671{ 4672 stbi s; 4673 int res; 4674 long n = ftell(f); 4675 start_file(&s, f); 4676 res = stbi_gif_info_raw(&s, x, y, comp); 4677 fseek(f, n, SEEK_SET); 4678 return res; 4679} 4680#endif // !STBI_NO_STDIO 4681 4682int stbi_gif_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) 4683{ 4684 stbi s; 4685 start_mem(&s, buffer, len); 4686 return stbi_gif_info_raw(&s, x, y, comp); 4687} 4688 4689 4690 4691 4692// ************************************************************************************************* 4693// Radiance RGBE HDR loader 4694// originally by Nicolas Schulz 4695#ifndef STBI_NO_HDR 4696static int hdr_test(stbi *s) 4697{ 4698 const char *signature = "#?RADIANCE\n"; 4699 int i; 4700 for (i=0; signature[i]; ++i) 4701 if (get8(s) != signature[i]) 4702 return 0; 4703 return 1; 4704} 4705 4706int stbi_hdr_test_memory(stbi_uc const *buffer, int len) 4707{ 4708 stbi s; 4709 start_mem(&s, buffer, len); 4710 return hdr_test(&s); 4711} 4712 4713#ifndef STBI_NO_STDIO 4714int stbi_hdr_test_file(FILE *f) 4715{ 4716 stbi s; 4717 int r,n = ftell(f); 4718 start_file(&s, f); 4719 r = hdr_test(&s); 4720 fseek(f,n,SEEK_SET); 4721 return r; 4722} 4723#endif 4724 4725#define HDR_BUFLEN 1024 4726static char *hdr_gettoken(stbi *z, char *buffer) 4727{ 4728 int len=0; 4729 char c = '\0'; 4730 4731 c = (char) get8(z); 4732 4733 while (!at_eof(z) && c != '\n') { 4734 buffer[len++] = c; 4735 if (len == HDR_BUFLEN-1) { 4736 // flush to end of line 4737 while (!at_eof(z) && get8(z) != '\n') 4738 ; 4739 break; 4740 } 4741 c = (char) get8(z); 4742 } 4743 4744 buffer[len] = 0; 4745 return buffer; 4746} 4747 4748static void hdr_convert(float *output, stbi_uc *input, int req_comp) 4749{ 4750 if ( input[3] != 0 ) { 4751 float f1; 4752 // Exponent 4753 f1 = (float) ldexp(1.0f, input[3] - (int)(128 + 8)); 4754 if (req_comp <= 2) 4755 output[0] = (input[0] + input[1] + input[2]) * f1 / 3; 4756 else { 4757 output[0] = input[0] * f1; 4758 output[1] = input[1] * f1; 4759 output[2] = input[2] * f1; 4760 } 4761 if (req_comp == 2) output[1] = 1; 4762 if (req_comp == 4) output[3] = 1; 4763 } else { 4764 switch (req_comp) { 4765 case 4: output[3] = 1; /* fallthrough */ 4766 case 3: output[0] = output[1] = output[2] = 0; 4767 break; 4768 case 2: output[1] = 1; /* fallthrough */ 4769 case 1: output[0] = 0; 4770 break; 4771 } 4772 } 4773} 4774 4775 4776static float *hdr_load(stbi *s, int *x, int *y, int *comp, int req_comp) 4777{ 4778 char buffer[HDR_BUFLEN]; 4779 char *token; 4780 int valid = 0; 4781 int width, height; 4782 stbi_uc *scanline; 4783 float *hdr_data; 4784 int len; 4785 unsigned char count, value; 4786 int i, j, k, c1,c2, z; 4787 4788 4789 // Check identifier 4790 if (strcmp(hdr_gettoken(s,buffer), "#?RADIANCE") != 0) 4791 return epf("not HDR", "Corrupt HDR image"); 4792 4793 // Parse header 4794 for(;;) { 4795 token = hdr_gettoken(s,buffer); 4796 if (token[0] == 0) break; 4797 if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1; 4798 } 4799 4800 if (!valid) return epf("unsupported format", "Unsupported HDR format"); 4801 4802 // Parse width and height 4803 // can't use sscanf() if we're not using stdio! 4804 token = hdr_gettoken(s,buffer); 4805 if (strncmp(token, "-Y ", 3)) return epf("unsupported data layout", "Unsupported HDR format"); 4806 token += 3; 4807 height = strtol(token, &token, 10); 4808 while (*token == ' ') ++token; 4809 if (strncmp(token, "+X ", 3)) return epf("unsupported data layout", "Unsupported HDR format"); 4810 token += 3; 4811 width = strtol(token, NULL, 10); 4812 4813 *x = width; 4814 *y = height; 4815 4816 *comp = 3; 4817 if (req_comp == 0) req_comp = 3; 4818 4819 // Read data 4820 hdr_data = MALLOC(height * width * req_comp * sizeof(float)); 4821 4822 // Load image data 4823 // image data is stored as some number of sca 4824 if ( width < 8 || width >= 32768) { 4825 // Read flat data 4826 for (j=0; j < height; ++j) { 4827 for (i=0; i < width; ++i) { 4828 stbi_uc rgbe[4]; 4829 main_decode_loop: 4830 getn(s, rgbe, 4); 4831 hdr_convert(hdr_data + j * width * req_comp + i * req_comp, rgbe, req_comp); 4832 } 4833 } 4834 } else { 4835 // Read RLE-encoded data 4836 scanline = NULL; 4837 4838 for (j = 0; j < height; ++j) { 4839 c1 = get8(s); 4840 c2 = get8(s); 4841 len = get8(s); 4842 if (c1 != 2 || c2 != 2 || (len & 0x80)) { 4843 // not run-length encoded, so we have to actually use THIS data as a decoded 4844 // pixel (note this can't be a valid pixel--one of RGB must be >= 128) 4845 uint8 rgbe[4]; 4846 rgbe[0] = (uint8) c1; 4847 rgbe[1] = (uint8) c2; 4848 rgbe[2] = (uint8) len; 4849 rgbe[3] = (uint8) get8u(s); 4850 hdr_convert(hdr_data, rgbe, req_comp); 4851 i = 1; 4852 j = 0; 4853 FREE(scanline); 4854 goto main_decode_loop; // yes, this makes no sense 4855 } 4856 len <<= 8; 4857 len |= get8(s); 4858 if (len != width) { FREE(hdr_data); FREE(scanline); return epf("invalid decoded scanline length", "corrupt HDR"); } 4859 if (scanline == NULL) scanline = MALLOC(width * 4); 4860 4861 for (k = 0; k < 4; ++k) { 4862 i = 0; 4863 while (i < width) { 4864 count = get8u(s); 4865 if (count > 128) { 4866 // Run 4867 value = get8u(s); 4868 count -= 128; 4869 for (z = 0; z < count; ++z) 4870 scanline[i++ * 4 + k] = value; 4871 } else { 4872 // Dump 4873 for (z = 0; z < count; ++z) 4874 scanline[i++ * 4 + k] = get8u(s); 4875 } 4876 } 4877 } 4878 for (i=0; i < width; ++i) 4879 hdr_convert(hdr_data+(j*width + i)*req_comp, scanline + i*4, req_comp); 4880 } 4881 FREE(scanline); 4882 } 4883 4884 return hdr_data; 4885} 4886 4887#ifndef STBI_NO_STDIO 4888float *stbi_hdr_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) 4889{ 4890 stbi s; 4891 start_file(&s,f); 4892 return hdr_load(&s,x,y,comp,req_comp); 4893} 4894#endif 4895 4896float *stbi_hdr_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) 4897{ 4898 stbi s; 4899 start_mem(&s,buffer, len); 4900 return hdr_load(&s,x,y,comp,req_comp); 4901} 4902 4903#endif // STBI_NO_HDR 4904 4905 4906#ifndef STBI_NO_STDIO 4907int stbi_info(char const *filename, int *x, int *y, int *comp) 4908{ 4909 FILE *f = fopen(filename, "rb"); 4910 int result; 4911 if (!f) return e("can't fopen", "Unable to open file"); 4912 result = stbi_info_from_file(f, x, y, comp); 4913 fclose(f); 4914 return result; 4915} 4916 4917int stbi_info_from_file(FILE *f, int *x, int *y, int *comp) 4918{ 4919 if (stbi_jpeg_info_from_file(f, x, y, comp)) 4920 return 1; 4921 if (stbi_png_info_from_file(f, x, y, comp)) 4922 return 1; 4923 if (stbi_gif_info_from_file(f, x, y, comp)) 4924 return 1; 4925 // @TODO: stbi_bmp_info_from_file 4926 // @TODO: stbi_psd_info_from_file 4927 #ifndef STBI_NO_HDR 4928 // @TODO: stbi_hdr_info_from_file 4929 #endif 4930 // test tga last because it's a crappy test! 4931 if (stbi_tga_info_from_file(f, x, y, comp)) 4932 return 1; 4933 return e("unknown image type", "Image not of any known type, or corrupt"); 4934} 4935#endif // !STBI_NO_STDIO 4936 4937int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp) 4938{ 4939 if (stbi_jpeg_info_from_memory(buffer, len, x, y, comp)) 4940 return 1; 4941 if (stbi_png_info_from_memory(buffer, len, x, y, comp)) 4942 return 1; 4943 if (stbi_gif_info_from_memory(buffer, len, x, y, comp)) 4944 return 1; 4945 // @TODO: stbi_bmp_info_from_memory 4946 // @TODO: stbi_psd_info_from_memory 4947 #ifndef STBI_NO_HDR 4948 // @TODO: stbi_hdr_info_from_memory 4949 #endif 4950 // test tga last because it's a crappy test! 4951 if (stbi_tga_info_from_memory(buffer, len, x, y, comp)) 4952 return 1; 4953 return e("unknown image type", "Image not of any known type, or corrupt"); 4954} 4955 4956#endif // STBI_HEADER_FILE_ONLY 4957 4958/* 4959 revision history: 4960 1.29 (2010-08-16) various warning fixes from Aurelien Pocheville 4961 1.28 (2010-08-01) fix bug in GIF palette transparency (SpartanJ) 4962 1.27 (2010-08-01) 4963 cast-to-uint8 to fix warnings 4964 1.26 (2010-07-24) 4965 fix bug in file buffering for PNG reported by SpartanJ 4966 1.25 (2010-07-17) 4967 refix trans_data warning (Won Chun) 4968 1.24 (2010-07-12) 4969 perf improvements reading from files on platforms with lock-heavy fgetc() 4970 minor perf improvements for jpeg 4971 deprecated type-specific functions so we'll get feedback if they're needed 4972 attempt to fix trans_data warning (Won Chun) 4973 1.23 fixed bug in iPhone support 4974 1.22 (2010-07-10) 4975 removed image *writing* support 4976 removed image *writing* support 4977 stbi_info support from Jetro Lauha 4978 GIF support from Jean-Marc Lienher 4979 iPhone PNG-extensions from James Brown 4980 warning-fixes from Nicolas Schulz and Janez Zemva (i.e. Janez (U+017D)emva) 4981 1.21 fix use of 'uint8' in header (reported by jon blow) 4982 1.20 added support for Softimage PIC, by Tom Seddon 4983 1.19 bug in interlaced PNG corruption check (found by ryg) 4984 1.18 2008-08-02 4985 fix a threading bug (local mutable static) 4986 1.17 support interlaced PNG 4987 1.16 major bugfix - convert_format converted one too many pixels 4988 1.15 initialize some fields for thread safety 4989 1.14 fix threadsafe conversion bug 4990 header-file-only version (#define STBI_HEADER_FILE_ONLY before including) 4991 1.13 threadsafe 4992 1.12 const qualifiers in the API 4993 1.11 Support installable IDCT, colorspace conversion routines 4994 1.10 Fixes for 64-bit (don't use "unsigned long") 4995 optimized upsampling by Fabian "ryg" Giesen 4996 1.09 Fix format-conversion for PSD code (bad global variables!) 4997 1.08 Thatcher Ulrich's PSD code integrated by Nicolas Schulz 4998 1.07 attempt to fix C++ warning/errors again 4999 1.06 attempt to fix C++ warning/errors again 5000 1.05 fix TGA loading to return correct *comp and use good luminance calc 5001 1.04 default float alpha is 1, not 255; use 'void *' for stbi_image_free 5002 1.03 bugfixes to STBI_NO_STDIO, STBI_NO_HDR 5003 1.02 support for (subset of) HDR files, float interface for preferred access to them 5004 1.01 fix bug: possible bug in handling right-side up bmps... not sure 5005 fix bug: the stbi_bmp_load() and stbi_tga_load() functions didn't work at all 5006 1.00 interface to zlib that skips zlib header 5007 0.99 correct handling of alpha in palette 5008 0.98 TGA loader by lonesock; dynamically add loaders (untested) 5009 0.97 jpeg errors on too large a file; also catch another malloc failure 5010 0.96 fix detection of invalid v value - particleman@mollyrocket forum 5011 0.95 during header scan, seek to markers in case of padding 5012 0.94 STBI_NO_STDIO to disable stdio usage; rename all #defines the same 5013 0.93 handle jpegtran output; verbose errors 5014 0.92 read 4,8,16,24,32-bit BMP files of several formats 5015 0.91 output 24-bit Windows 3.0 BMP files 5016 0.90 fix a few more warnings; bump version number to approach 1.0 5017 0.61 bugfixes due to Marc LeBlanc, Christopher Lloyd 5018 0.60 fix compiling as c++ 5019 0.59 fix warnings: merge Dave Moore's -Wall fixes 5020 0.58 fix bug: zlib uncompressed mode len/nlen was wrong endian 5021 0.57 fix bug: jpg last huffman symbol before marker was >9 bits but less 5022 than 16 available 5023 0.56 fix bug: zlib uncompressed mode len vs. nlen 5024 0.55 fix bug: restart_interval not initialized to 0 5025 0.54 allow NULL for 'int *comp' 5026 0.53 fix bug in png 3->4; speedup png decoding 5027 0.52 png handles req_comp=3,4 directly; minor cleanup; jpeg comments 5028 0.51 obey req_comp requests, 1-component jpegs return as 1-component, 5029 on 'test' only check type, not whether we support this variant 5030*/ 5031
