1 | /* stbi-1.16 - public domain JPEG/PNG reader - http://nothings.org/stb_image.c |
2 | when you control the images you're loading |
3 | |
4 | QUICK NOTES: |
5 | Primarily of interest to game developers and other people who can |
6 | avoid problematic images and only need the trivial interface |
7 | |
8 | JPEG baseline (no JPEG progressive, no oddball channel decimations) |
9 | PNG non-interlaced |
10 | BMP non-1bpp, non-RLE |
11 | TGA (not sure what subset, if a subset) |
12 | PSD (composited view only, no extra channels) |
13 | HDR (radiance rgbE format) |
14 | writes BMP,TGA (define STBI_NO_WRITE to remove code) |
15 | decoded from memory or through stdio FILE (define STBI_NO_STDIO to remove code) |
16 | supports installable dequantizing-IDCT, YCbCr-to-RGB conversion (define STBI_SIMD) |
17 | |
18 | TODO: |
19 | stbi_info_* |
20 | |
21 | history: |
22 | 1.16 major bugfix - convert_format converted one too many pixels |
23 | 1.15 initialize some fields for thread safety |
24 | 1.14 fix threadsafe conversion bug; header-file-only version (#define STBI_HEADER_FILE_ONLY before including) |
25 | 1.13 threadsafe |
26 | 1.12 const qualifiers in the API |
27 | 1.11 Support installable IDCT, colorspace conversion routines |
28 | 1.10 Fixes for 64-bit (don't use "unsigned long") |
29 | optimized upsampling by Fabian "ryg" Giesen |
30 | 1.09 Fix format-conversion for PSD code (bad global variables!) |
31 | 1.08 Thatcher Ulrich's PSD code integrated by Nicolas Schulz |
32 | 1.07 attempt to fix C++ warning/errors again |
33 | 1.06 attempt to fix C++ warning/errors again |
34 | 1.05 fix TGA loading to return correct *comp and use good luminance calc |
35 | 1.04 default float alpha is 1, not 255; use 'void *' for stbi_image_free |
36 | 1.03 bugfixes to STBI_NO_STDIO, STBI_NO_HDR |
37 | 1.02 support for (subset of) HDR files, float interface for preferred access to them |
38 | 1.01 fix bug: possible bug in handling right-side up bmps... not sure |
39 | fix bug: the stbi_bmp_load() and stbi_tga_load() functions didn't work at all |
40 | 1.00 interface to zlib that skips zlib header |
41 | 0.99 correct handling of alpha in palette |
42 | 0.98 TGA loader by lonesock; dynamically add loaders (untested) |
43 | 0.97 jpeg errors on too large a file; also catch another malloc failure |
44 | 0.96 fix detection of invalid v value - particleman@mollyrocket forum |
45 | 0.95 during header scan, seek to markers in case of padding |
46 | 0.94 STBI_NO_STDIO to disable stdio usage; rename all #defines the same |
47 | 0.93 handle jpegtran output; verbose errors |
48 | 0.92 read 4,8,16,24,32-bit BMP files of several formats |
49 | 0.91 output 24-bit Windows 3.0 BMP files |
50 | 0.90 fix a few more warnings; bump version number to approach 1.0 |
51 | 0.61 bugfixes due to Marc LeBlanc, Christopher Lloyd |
52 | 0.60 fix compiling as c++ |
53 | 0.59 fix warnings: merge Dave Moore's -Wall fixes |
54 | 0.58 fix bug: zlib uncompressed mode len/nlen was wrong endian |
55 | 0.57 fix bug: jpg last huffman symbol before marker was >9 bits but less |
56 | than 16 available |
57 | 0.56 fix bug: zlib uncompressed mode len vs. nlen |
58 | 0.55 fix bug: restart_interval not initialized to 0 |
59 | 0.54 allow NULL for 'int *comp' |
60 | 0.53 fix bug in png 3->4; speedup png decoding |
61 | 0.52 png handles req_comp=3,4 directly; minor cleanup; jpeg comments |
62 | 0.51 obey req_comp requests, 1-component jpegs return as 1-component, |
63 | on 'test' only check type, not whether we support this variant |
64 | */ |
65 | |
66 | #include "stb_image_aug.h" |
67 | |
68 | #ifndef STBI_NO_HDR |
69 | #include <math.h> // ldexp |
70 | #include <string.h> // strcmp |
71 | #endif |
72 | |
73 | #ifndef STBI_NO_STDIO |
74 | #include <stdio.h> |
75 | #endif |
76 | #include <stdlib.h> |
77 | #include <memory.h> |
78 | #include <assert.h> |
79 | #include <stdarg.h> |
80 | |
81 | #ifndef _MSC_VER |
82 | #ifdef __cplusplus |
83 | #define __forceinline inline |
84 | #else |
85 | #define __forceinline |
86 | #endif |
87 | #endif |
88 | |
89 | |
90 | // implementation: |
91 | typedef unsigned char uint8; |
92 | typedef unsigned short uint16; |
93 | typedef signed short int16; |
94 | typedef unsigned int uint32; |
95 | typedef signed int int32; |
96 | typedef unsigned int uint; |
97 | |
98 | // should produce compiler error if size is wrong |
99 | typedef unsigned char validate_uint32[sizeof(uint32)==4]; |
100 | |
101 | #if defined(STBI_NO_STDIO) && !defined(STBI_NO_WRITE) |
102 | #define STBI_NO_WRITE |
103 | #endif |
104 | |
105 | #ifndef STBI_NO_DDS |
106 | #include "stbi_DDS_aug.h" |
107 | #endif |
108 | |
109 | // I (JLD) want full messages for SOIL |
110 | #define STBI_FAILURE_USERMSG 1 |
111 | |
112 | ////////////////////////////////////////////////////////////////////////////// |
113 | // |
114 | // Generic API that works on all image types |
115 | // |
116 | |
117 | // this is not threadsafe |
118 | static char *failure_reason; |
119 | |
120 | char *stbi_failure_reason(void) |
121 | { |
122 | return failure_reason; |
123 | } |
124 | |
125 | static int e(char *str) |
126 | { |
127 | failure_reason = str; |
128 | return 0; |
129 | } |
130 | |
131 | #ifdef STBI_NO_FAILURE_STRINGS |
132 | #define e(x,y) 0 |
133 | #elif defined(STBI_FAILURE_USERMSG) |
134 | #define e(x,y) e(y) |
135 | #else |
136 | #define e(x,y) e(x) |
137 | #endif |
138 | |
139 | #define epf(x,y) ((float *) (e(x,y)?NULL:NULL)) |
140 | #define epuc(x,y) ((unsigned char *) (e(x,y)?NULL:NULL)) |
141 | |
142 | void stbi_image_free(void *retval_from_stbi_load) |
143 | { |
144 | free(retval_from_stbi_load); |
145 | } |
146 | |
147 | #define MAX_LOADERS 32 |
148 | stbi_loader *loaders[MAX_LOADERS]; |
149 | static int max_loaders = 0; |
150 | |
151 | int stbi_register_loader(stbi_loader *loader) |
152 | { |
153 | int i; |
154 | for (i=0; i < MAX_LOADERS; ++i) { |
155 | // already present? |
156 | if (loaders[i] == loader) |
157 | return 1; |
158 | // end of the list? |
159 | if (loaders[i] == NULL) { |
160 | loaders[i] = loader; |
161 | max_loaders = i+1; |
162 | return 1; |
163 | } |
164 | } |
165 | // no room for it |
166 | return 0; |
167 | } |
168 | |
169 | #ifndef STBI_NO_HDR |
170 | static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp); |
171 | static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp); |
172 | #endif |
173 | |
174 | #ifndef STBI_NO_STDIO |
175 | unsigned char *stbi_load(char const *filename, int *x, int *y, int *comp, int req_comp) |
176 | { |
177 | FILE *f = fopen(filename, "rb" ); |
178 | unsigned char *result; |
179 | if (!f) return epuc("can't fopen" , "Unable to open file" ); |
180 | result = stbi_load_from_file(f,x,y,comp,req_comp); |
181 | fclose(f); |
182 | return result; |
183 | } |
184 | |
185 | unsigned char *stbi_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) |
186 | { |
187 | int i; |
188 | if (stbi_jpeg_test_file(f)) |
189 | return stbi_jpeg_load_from_file(f,x,y,comp,req_comp); |
190 | if (stbi_png_test_file(f)) |
191 | return stbi_png_load_from_file(f,x,y,comp,req_comp); |
192 | if (stbi_bmp_test_file(f)) |
193 | return stbi_bmp_load_from_file(f,x,y,comp,req_comp); |
194 | if (stbi_psd_test_file(f)) |
195 | return stbi_psd_load_from_file(f,x,y,comp,req_comp); |
196 | #ifndef STBI_NO_DDS |
197 | if (stbi_dds_test_file(f)) |
198 | return stbi_dds_load_from_file(f,x,y,comp,req_comp); |
199 | #endif |
200 | #ifndef STBI_NO_HDR |
201 | if (stbi_hdr_test_file(f)) { |
202 | float *hdr = stbi_hdr_load_from_file(f, x,y,comp,req_comp); |
203 | return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp); |
204 | } |
205 | #endif |
206 | for (i=0; i < max_loaders; ++i) |
207 | if (loaders[i]->test_file(f)) |
208 | return loaders[i]->load_from_file(f,x,y,comp,req_comp); |
209 | // test tga last because it's a crappy test! |
210 | if (stbi_tga_test_file(f)) |
211 | return stbi_tga_load_from_file(f,x,y,comp,req_comp); |
212 | return epuc("unknown image type" , "Image not of any known type, or corrupt" ); |
213 | } |
214 | #endif |
215 | |
216 | unsigned char *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) |
217 | { |
218 | int i; |
219 | if (stbi_jpeg_test_memory(buffer,len)) |
220 | return stbi_jpeg_load_from_memory(buffer,len,x,y,comp,req_comp); |
221 | if (stbi_png_test_memory(buffer,len)) |
222 | return stbi_png_load_from_memory(buffer,len,x,y,comp,req_comp); |
223 | if (stbi_bmp_test_memory(buffer,len)) |
224 | return stbi_bmp_load_from_memory(buffer,len,x,y,comp,req_comp); |
225 | if (stbi_psd_test_memory(buffer,len)) |
226 | return stbi_psd_load_from_memory(buffer,len,x,y,comp,req_comp); |
227 | #ifndef STBI_NO_DDS |
228 | if (stbi_dds_test_memory(buffer,len)) |
229 | return stbi_dds_load_from_memory(buffer,len,x,y,comp,req_comp); |
230 | #endif |
231 | #ifndef STBI_NO_HDR |
232 | if (stbi_hdr_test_memory(buffer, len)) { |
233 | float *hdr = stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp); |
234 | return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp); |
235 | } |
236 | #endif |
237 | for (i=0; i < max_loaders; ++i) |
238 | if (loaders[i]->test_memory(buffer,len)) |
239 | return loaders[i]->load_from_memory(buffer,len,x,y,comp,req_comp); |
240 | // test tga last because it's a crappy test! |
241 | if (stbi_tga_test_memory(buffer,len)) |
242 | return stbi_tga_load_from_memory(buffer,len,x,y,comp,req_comp); |
243 | return epuc("unknown image type" , "Image not of any known type, or corrupt" ); |
244 | } |
245 | |
246 | #ifndef STBI_NO_HDR |
247 | |
248 | #ifndef STBI_NO_STDIO |
249 | float *stbi_loadf(char const *filename, int *x, int *y, int *comp, int req_comp) |
250 | { |
251 | FILE *f = fopen(filename, "rb" ); |
252 | float *result; |
253 | if (!f) return epf("can't fopen" , "Unable to open file" ); |
254 | result = stbi_loadf_from_file(f,x,y,comp,req_comp); |
255 | fclose(f); |
256 | return result; |
257 | } |
258 | |
259 | float *stbi_loadf_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) |
260 | { |
261 | unsigned char *data; |
262 | #ifndef STBI_NO_HDR |
263 | if (stbi_hdr_test_file(f)) |
264 | return stbi_hdr_load_from_file(f,x,y,comp,req_comp); |
265 | #endif |
266 | data = stbi_load_from_file(f, x, y, comp, req_comp); |
267 | if (data) |
268 | return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp); |
269 | return epf("unknown image type" , "Image not of any known type, or corrupt" ); |
270 | } |
271 | #endif |
272 | |
273 | float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) |
274 | { |
275 | stbi_uc *data; |
276 | #ifndef STBI_NO_HDR |
277 | if (stbi_hdr_test_memory(buffer, len)) |
278 | return stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp); |
279 | #endif |
280 | data = stbi_load_from_memory(buffer, len, x, y, comp, req_comp); |
281 | if (data) |
282 | return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp); |
283 | return epf("unknown image type" , "Image not of any known type, or corrupt" ); |
284 | } |
285 | #endif |
286 | |
287 | // these is-hdr-or-not is defined independent of whether STBI_NO_HDR is |
288 | // defined, for API simplicity; if STBI_NO_HDR is defined, it always |
289 | // reports false! |
290 | |
291 | int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len) |
292 | { |
293 | #ifndef STBI_NO_HDR |
294 | return stbi_hdr_test_memory(buffer, len); |
295 | #else |
296 | return 0; |
297 | #endif |
298 | } |
299 | |
300 | #ifndef STBI_NO_STDIO |
301 | extern int stbi_is_hdr (char const *filename) |
302 | { |
303 | FILE *f = fopen(filename, "rb" ); |
304 | int result=0; |
305 | if (f) { |
306 | result = stbi_is_hdr_from_file(f); |
307 | fclose(f); |
308 | } |
309 | return result; |
310 | } |
311 | |
312 | extern int stbi_is_hdr_from_file(FILE *f) |
313 | { |
314 | #ifndef STBI_NO_HDR |
315 | return stbi_hdr_test_file(f); |
316 | #else |
317 | return 0; |
318 | #endif |
319 | } |
320 | |
321 | #endif |
322 | |
323 | // @TODO: get image dimensions & components without fully decoding |
324 | #ifndef STBI_NO_STDIO |
325 | extern int stbi_info (char const *filename, int *x, int *y, int *comp); |
326 | extern int stbi_info_from_file (FILE *f, int *x, int *y, int *comp); |
327 | #endif |
328 | extern int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); |
329 | |
330 | #ifndef STBI_NO_HDR |
331 | static float h2l_gamma_i=1.0f/2.2f, h2l_scale_i=1.0f; |
332 | static float l2h_gamma=2.2f, l2h_scale=1.0f; |
333 | |
334 | void stbi_hdr_to_ldr_gamma(float gamma) { h2l_gamma_i = 1/gamma; } |
335 | void stbi_hdr_to_ldr_scale(float scale) { h2l_scale_i = 1/scale; } |
336 | |
337 | void stbi_ldr_to_hdr_gamma(float gamma) { l2h_gamma = gamma; } |
338 | void stbi_ldr_to_hdr_scale(float scale) { l2h_scale = scale; } |
339 | #endif |
340 | |
341 | |
342 | ////////////////////////////////////////////////////////////////////////////// |
343 | // |
344 | // Common code used by all image loaders |
345 | // |
346 | |
347 | enum |
348 | { |
349 | SCAN_load=0, |
350 | SCAN_type, |
351 | , |
352 | }; |
353 | |
354 | typedef struct |
355 | { |
356 | uint32 img_x, img_y; |
357 | int img_n, img_out_n; |
358 | |
359 | #ifndef STBI_NO_STDIO |
360 | FILE *img_file; |
361 | #endif |
362 | uint8 *img_buffer, *img_buffer_end; |
363 | } stbi; |
364 | |
365 | #ifndef STBI_NO_STDIO |
366 | static void start_file(stbi *s, FILE *f) |
367 | { |
368 | s->img_file = f; |
369 | } |
370 | #endif |
371 | |
372 | static void start_mem(stbi *s, uint8 const *buffer, int len) |
373 | { |
374 | #ifndef STBI_NO_STDIO |
375 | s->img_file = NULL; |
376 | #endif |
377 | s->img_buffer = (uint8 *) buffer; |
378 | s->img_buffer_end = (uint8 *) buffer+len; |
379 | } |
380 | |
381 | __forceinline static int get8(stbi *s) |
382 | { |
383 | #ifndef STBI_NO_STDIO |
384 | if (s->img_file) { |
385 | int c = fgetc(s->img_file); |
386 | return c == EOF ? 0 : c; |
387 | } |
388 | #endif |
389 | if (s->img_buffer < s->img_buffer_end) |
390 | return *s->img_buffer++; |
391 | return 0; |
392 | } |
393 | |
394 | __forceinline static int at_eof(stbi *s) |
395 | { |
396 | #ifndef STBI_NO_STDIO |
397 | if (s->img_file) |
398 | return feof(s->img_file); |
399 | #endif |
400 | return s->img_buffer >= s->img_buffer_end; |
401 | } |
402 | |
403 | __forceinline static uint8 get8u(stbi *s) |
404 | { |
405 | return (uint8) get8(s); |
406 | } |
407 | |
408 | static void skip(stbi *s, int n) |
409 | { |
410 | #ifndef STBI_NO_STDIO |
411 | if (s->img_file) |
412 | fseek(s->img_file, n, SEEK_CUR); |
413 | else |
414 | #endif |
415 | s->img_buffer += n; |
416 | } |
417 | |
418 | static int get16(stbi *s) |
419 | { |
420 | int z = get8(s); |
421 | return (z << 8) + get8(s); |
422 | } |
423 | |
424 | static uint32 get32(stbi *s) |
425 | { |
426 | uint32 z = get16(s); |
427 | return (z << 16) + get16(s); |
428 | } |
429 | |
430 | static int get16le(stbi *s) |
431 | { |
432 | int z = get8(s); |
433 | return z + (get8(s) << 8); |
434 | } |
435 | |
436 | static uint32 get32le(stbi *s) |
437 | { |
438 | uint32 z = get16le(s); |
439 | return z + (get16le(s) << 16); |
440 | } |
441 | |
442 | static void getn(stbi *s, stbi_uc *buffer, int n) |
443 | { |
444 | #ifndef STBI_NO_STDIO |
445 | if (s->img_file) { |
446 | fread(buffer, 1, n, s->img_file); |
447 | return; |
448 | } |
449 | #endif |
450 | memcpy(buffer, s->img_buffer, n); |
451 | s->img_buffer += n; |
452 | } |
453 | |
454 | ////////////////////////////////////////////////////////////////////////////// |
455 | // |
456 | // generic converter from built-in img_n to req_comp |
457 | // individual types do this automatically as much as possible (e.g. jpeg |
458 | // does all cases internally since it needs to colorspace convert anyway, |
459 | // and it never has alpha, so very few cases ). png can automatically |
460 | // interleave an alpha=255 channel, but falls back to this for other cases |
461 | // |
462 | // assume data buffer is malloced, so malloc a new one and free that one |
463 | // only failure mode is malloc failing |
464 | |
465 | static uint8 compute_y(int r, int g, int b) |
466 | { |
467 | return (uint8) (((r*77) + (g*150) + (29*b)) >> 8); |
468 | } |
469 | |
470 | static unsigned char *convert_format(unsigned char *data, int img_n, int req_comp, uint x, uint y) |
471 | { |
472 | int i,j; |
473 | unsigned char *good; |
474 | |
475 | if (req_comp == img_n) return data; |
476 | assert(req_comp >= 1 && req_comp <= 4); |
477 | |
478 | good = (unsigned char *) malloc(req_comp * x * y); |
479 | if (good == NULL) { |
480 | free(data); |
481 | return epuc("outofmem" , "Out of memory" ); |
482 | } |
483 | |
484 | for (j=0; j < (int) y; ++j) { |
485 | unsigned char *src = data + j * x * img_n ; |
486 | unsigned char *dest = good + j * x * req_comp; |
487 | |
488 | #define COMBO(a,b) ((a)*8+(b)) |
489 | #define CASE(a,b) case COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b) |
490 | // convert source image with img_n components to one with req_comp components; |
491 | // avoid switch per pixel, so use switch per scanline and massive macros |
492 | switch(COMBO(img_n, req_comp)) { |
493 | CASE(1,2) dest[0]=src[0], dest[1]=255; break; |
494 | CASE(1,3) dest[0]=dest[1]=dest[2]=src[0]; break; |
495 | CASE(1,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=255; break; |
496 | CASE(2,1) dest[0]=src[0]; break; |
497 | CASE(2,3) dest[0]=dest[1]=dest[2]=src[0]; break; |
498 | CASE(2,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=src[1]; break; |
499 | CASE(3,4) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2],dest[3]=255; break; |
500 | CASE(3,1) dest[0]=compute_y(src[0],src[1],src[2]); break; |
501 | CASE(3,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = 255; break; |
502 | CASE(4,1) dest[0]=compute_y(src[0],src[1],src[2]); break; |
503 | CASE(4,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = src[3]; break; |
504 | CASE(4,3) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2]; break; |
505 | default: assert(0); |
506 | } |
507 | #undef CASE |
508 | } |
509 | |
510 | free(data); |
511 | return good; |
512 | } |
513 | |
514 | #ifndef STBI_NO_HDR |
515 | static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp) |
516 | { |
517 | int i,k,n; |
518 | float *output = (float *) malloc(x * y * comp * sizeof(float)); |
519 | if (output == NULL) { free(data); return epf("outofmem" , "Out of memory" ); } |
520 | // compute number of non-alpha components |
521 | if (comp & 1) n = comp; else n = comp-1; |
522 | for (i=0; i < x*y; ++i) { |
523 | for (k=0; k < n; ++k) { |
524 | output[i*comp + k] = (float) pow(data[i*comp+k]/255.0f, l2h_gamma) * l2h_scale; |
525 | } |
526 | if (k < comp) output[i*comp + k] = data[i*comp+k]/255.0f; |
527 | } |
528 | free(data); |
529 | return output; |
530 | } |
531 | |
532 | #define float2int(x) ((int) (x)) |
533 | static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp) |
534 | { |
535 | int i,k,n; |
536 | stbi_uc *output = (stbi_uc *) malloc(x * y * comp); |
537 | if (output == NULL) { free(data); return epuc("outofmem" , "Out of memory" ); } |
538 | // compute number of non-alpha components |
539 | if (comp & 1) n = comp; else n = comp-1; |
540 | for (i=0; i < x*y; ++i) { |
541 | for (k=0; k < n; ++k) { |
542 | float z = (float) pow(data[i*comp+k]*h2l_scale_i, h2l_gamma_i) * 255 + 0.5f; |
543 | if (z < 0) z = 0; |
544 | if (z > 255) z = 255; |
545 | output[i*comp + k] = float2int(z); |
546 | } |
547 | if (k < comp) { |
548 | float z = data[i*comp+k] * 255 + 0.5f; |
549 | if (z < 0) z = 0; |
550 | if (z > 255) z = 255; |
551 | output[i*comp + k] = float2int(z); |
552 | } |
553 | } |
554 | free(data); |
555 | return output; |
556 | } |
557 | #endif |
558 | |
559 | ////////////////////////////////////////////////////////////////////////////// |
560 | // |
561 | // "baseline" JPEG/JFIF decoder (not actually fully baseline implementation) |
562 | // |
563 | // simple implementation |
564 | // - channel subsampling of at most 2 in each dimension |
565 | // - doesn't support delayed output of y-dimension |
566 | // - simple interface (only one output format: 8-bit interleaved RGB) |
567 | // - doesn't try to recover corrupt jpegs |
568 | // - doesn't allow partial loading, loading multiple at once |
569 | // - still fast on x86 (copying globals into locals doesn't help x86) |
570 | // - allocates lots of intermediate memory (full size of all components) |
571 | // - non-interleaved case requires this anyway |
572 | // - allows good upsampling (see next) |
573 | // high-quality |
574 | // - upsampled channels are bilinearly interpolated, even across blocks |
575 | // - quality integer IDCT derived from IJG's 'slow' |
576 | // performance |
577 | // - fast huffman; reasonable integer IDCT |
578 | // - uses a lot of intermediate memory, could cache poorly |
579 | // - load http://nothings.org/remote/anemones.jpg 3 times on 2.8Ghz P4 |
580 | // stb_jpeg: 1.34 seconds (MSVC6, default release build) |
581 | // stb_jpeg: 1.06 seconds (MSVC6, processor = Pentium Pro) |
582 | // IJL11.dll: 1.08 seconds (compiled by intel) |
583 | // IJG 1998: 0.98 seconds (MSVC6, makefile provided by IJG) |
584 | // IJG 1998: 0.95 seconds (MSVC6, makefile + proc=PPro) |
585 | |
586 | // huffman decoding acceleration |
587 | #define FAST_BITS 9 // larger handles more cases; smaller stomps less cache |
588 | |
589 | typedef struct |
590 | { |
591 | uint8 fast[1 << FAST_BITS]; |
592 | // weirdly, repacking this into AoS is a 10% speed loss, instead of a win |
593 | uint16 code[256]; |
594 | uint8 values[256]; |
595 | uint8 size[257]; |
596 | unsigned int maxcode[18]; |
597 | int delta[17]; // old 'firstsymbol' - old 'firstcode' |
598 | } huffman; |
599 | |
600 | typedef struct |
601 | { |
602 | #if STBI_SIMD |
603 | unsigned short dequant2[4][64]; |
604 | #endif |
605 | stbi s; |
606 | huffman huff_dc[4]; |
607 | huffman huff_ac[4]; |
608 | uint8 dequant[4][64]; |
609 | |
610 | // sizes for components, interleaved MCUs |
611 | int img_h_max, img_v_max; |
612 | int img_mcu_x, img_mcu_y; |
613 | int img_mcu_w, img_mcu_h; |
614 | |
615 | // definition of jpeg image component |
616 | struct |
617 | { |
618 | int id; |
619 | int h,v; |
620 | int tq; |
621 | int hd,ha; |
622 | int dc_pred; |
623 | |
624 | int x,y,w2,h2; |
625 | uint8 *data; |
626 | void *raw_data; |
627 | uint8 *linebuf; |
628 | } img_comp[4]; |
629 | |
630 | uint32 code_buffer; // jpeg entropy-coded buffer |
631 | int code_bits; // number of valid bits |
632 | unsigned char marker; // marker seen while filling entropy buffer |
633 | int nomore; // flag if we saw a marker so must stop |
634 | |
635 | int scan_n, order[4]; |
636 | int restart_interval, todo; |
637 | } jpeg; |
638 | |
639 | static int build_huffman(huffman *h, int *count) |
640 | { |
641 | int i,j,k=0,code; |
642 | // build size list for each symbol (from JPEG spec) |
643 | for (i=0; i < 16; ++i) |
644 | for (j=0; j < count[i]; ++j) |
645 | h->size[k++] = (uint8) (i+1); |
646 | h->size[k] = 0; |
647 | |
648 | // compute actual symbols (from jpeg spec) |
649 | code = 0; |
650 | k = 0; |
651 | for(j=1; j <= 16; ++j) { |
652 | // compute delta to add to code to compute symbol id |
653 | h->delta[j] = k - code; |
654 | if (h->size[k] == j) { |
655 | while (h->size[k] == j) |
656 | h->code[k++] = (uint16) (code++); |
657 | if (code-1 >= (1 << j)) return e("bad code lengths" ,"Corrupt JPEG" ); |
658 | } |
659 | // compute largest code + 1 for this size, preshifted as needed later |
660 | h->maxcode[j] = code << (16-j); |
661 | code <<= 1; |
662 | } |
663 | h->maxcode[j] = 0xffffffff; |
664 | |
665 | // build non-spec acceleration table; 255 is flag for not-accelerated |
666 | memset(h->fast, 255, 1 << FAST_BITS); |
667 | for (i=0; i < k; ++i) { |
668 | int s = h->size[i]; |
669 | if (s <= FAST_BITS) { |
670 | int c = h->code[i] << (FAST_BITS-s); |
671 | int m = 1 << (FAST_BITS-s); |
672 | for (j=0; j < m; ++j) { |
673 | h->fast[c+j] = (uint8) i; |
674 | } |
675 | } |
676 | } |
677 | return 1; |
678 | } |
679 | |
680 | static void grow_buffer_unsafe(jpeg *j) |
681 | { |
682 | do { |
683 | int b = j->nomore ? 0 : get8(&j->s); |
684 | if (b == 0xff) { |
685 | int c = get8(&j->s); |
686 | if (c != 0) { |
687 | j->marker = (unsigned char) c; |
688 | j->nomore = 1; |
689 | return; |
690 | } |
691 | } |
692 | j->code_buffer = (j->code_buffer << 8) | b; |
693 | j->code_bits += 8; |
694 | } while (j->code_bits <= 24); |
695 | } |
696 | |
697 | // (1 << n) - 1 |
698 | static uint32 bmask[17]={0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535}; |
699 | |
700 | // decode a jpeg huffman value from the bitstream |
701 | __forceinline static int decode(jpeg *j, huffman *h) |
702 | { |
703 | unsigned int temp; |
704 | int c,k; |
705 | |
706 | if (j->code_bits < 16) grow_buffer_unsafe(j); |
707 | |
708 | // look at the top FAST_BITS and determine what symbol ID it is, |
709 | // if the code is <= FAST_BITS |
710 | c = (j->code_buffer >> (j->code_bits - FAST_BITS)) & ((1 << FAST_BITS)-1); |
711 | k = h->fast[c]; |
712 | if (k < 255) { |
713 | if (h->size[k] > j->code_bits) |
714 | return -1; |
715 | j->code_bits -= h->size[k]; |
716 | return h->values[k]; |
717 | } |
718 | |
719 | // naive test is to shift the code_buffer down so k bits are |
720 | // valid, then test against maxcode. To speed this up, we've |
721 | // preshifted maxcode left so that it has (16-k) 0s at the |
722 | // end; in other words, regardless of the number of bits, it |
723 | // wants to be compared against something shifted to have 16; |
724 | // that way we don't need to shift inside the loop. |
725 | if (j->code_bits < 16) |
726 | temp = (j->code_buffer << (16 - j->code_bits)) & 0xffff; |
727 | else |
728 | temp = (j->code_buffer >> (j->code_bits - 16)) & 0xffff; |
729 | for (k=FAST_BITS+1 ; ; ++k) |
730 | if (temp < h->maxcode[k]) |
731 | break; |
732 | if (k == 17) { |
733 | // error! code not found |
734 | j->code_bits -= 16; |
735 | return -1; |
736 | } |
737 | |
738 | if (k > j->code_bits) |
739 | return -1; |
740 | |
741 | // convert the huffman code to the symbol id |
742 | c = ((j->code_buffer >> (j->code_bits - k)) & bmask[k]) + h->delta[k]; |
743 | assert((((j->code_buffer) >> (j->code_bits - h->size[c])) & bmask[h->size[c]]) == h->code[c]); |
744 | |
745 | // convert the id to a symbol |
746 | j->code_bits -= k; |
747 | return h->values[c]; |
748 | } |
749 | |
750 | // combined JPEG 'receive' and JPEG 'extend', since baseline |
751 | // always extends everything it receives. |
752 | __forceinline static int extend_receive(jpeg *j, int n) |
753 | { |
754 | unsigned int m = 1 << (n-1); |
755 | unsigned int k; |
756 | if (j->code_bits < n) grow_buffer_unsafe(j); |
757 | k = (j->code_buffer >> (j->code_bits - n)) & bmask[n]; |
758 | j->code_bits -= n; |
759 | // the following test is probably a random branch that won't |
760 | // predict well. I tried to table accelerate it but failed. |
761 | // maybe it's compiling as a conditional move? |
762 | if (k < m) |
763 | return (-1 << n) + k + 1; |
764 | else |
765 | return k; |
766 | } |
767 | |
768 | // given a value that's at position X in the zigzag stream, |
769 | // where does it appear in the 8x8 matrix coded as row-major? |
770 | static uint8 dezigzag[64+15] = |
771 | { |
772 | 0, 1, 8, 16, 9, 2, 3, 10, |
773 | 17, 24, 32, 25, 18, 11, 4, 5, |
774 | 12, 19, 26, 33, 40, 48, 41, 34, |
775 | 27, 20, 13, 6, 7, 14, 21, 28, |
776 | 35, 42, 49, 56, 57, 50, 43, 36, |
777 | 29, 22, 15, 23, 30, 37, 44, 51, |
778 | 58, 59, 52, 45, 38, 31, 39, 46, |
779 | 53, 60, 61, 54, 47, 55, 62, 63, |
780 | // let corrupt input sample past end |
781 | 63, 63, 63, 63, 63, 63, 63, 63, |
782 | 63, 63, 63, 63, 63, 63, 63 |
783 | }; |
784 | |
785 | // decode one 64-entry block-- |
786 | static int decode_block(jpeg *j, short data[64], huffman *hdc, huffman *hac, int b) |
787 | { |
788 | int diff,dc,k; |
789 | int t = decode(j, hdc); |
790 | if (t < 0) return e("bad huffman code" ,"Corrupt JPEG" ); |
791 | |
792 | // 0 all the ac values now so we can do it 32-bits at a time |
793 | memset(data,0,64*sizeof(data[0])); |
794 | |
795 | diff = t ? extend_receive(j, t) : 0; |
796 | dc = j->img_comp[b].dc_pred + diff; |
797 | j->img_comp[b].dc_pred = dc; |
798 | data[0] = (short) dc; |
799 | |
800 | // decode AC components, see JPEG spec |
801 | k = 1; |
802 | do { |
803 | int r,s; |
804 | int rs = decode(j, hac); |
805 | if (rs < 0) return e("bad huffman code" ,"Corrupt JPEG" ); |
806 | s = rs & 15; |
807 | r = rs >> 4; |
808 | if (s == 0) { |
809 | if (rs != 0xf0) break; // end block |
810 | k += 16; |
811 | } else { |
812 | k += r; |
813 | // decode into unzigzag'd location |
814 | data[dezigzag[k++]] = (short) extend_receive(j,s); |
815 | } |
816 | } while (k < 64); |
817 | return 1; |
818 | } |
819 | |
820 | // take a -128..127 value and clamp it and convert to 0..255 |
821 | __forceinline static uint8 clamp(int x) |
822 | { |
823 | x += 128; |
824 | // trick to use a single test to catch both cases |
825 | if ((unsigned int) x > 255) { |
826 | if (x < 0) return 0; |
827 | if (x > 255) return 255; |
828 | } |
829 | return (uint8) x; |
830 | } |
831 | |
832 | #define f2f(x) (int) (((x) * 4096 + 0.5)) |
833 | #define fsh(x) ((x) << 12) |
834 | |
835 | // derived from jidctint -- DCT_ISLOW |
836 | #define IDCT_1D(s0,s1,s2,s3,s4,s5,s6,s7) \ |
837 | int t0,t1,t2,t3,p1,p2,p3,p4,p5,x0,x1,x2,x3; \ |
838 | p2 = s2; \ |
839 | p3 = s6; \ |
840 | p1 = (p2+p3) * f2f(0.5411961f); \ |
841 | t2 = p1 + p3*f2f(-1.847759065f); \ |
842 | t3 = p1 + p2*f2f( 0.765366865f); \ |
843 | p2 = s0; \ |
844 | p3 = s4; \ |
845 | t0 = fsh(p2+p3); \ |
846 | t1 = fsh(p2-p3); \ |
847 | x0 = t0+t3; \ |
848 | x3 = t0-t3; \ |
849 | x1 = t1+t2; \ |
850 | x2 = t1-t2; \ |
851 | t0 = s7; \ |
852 | t1 = s5; \ |
853 | t2 = s3; \ |
854 | t3 = s1; \ |
855 | p3 = t0+t2; \ |
856 | p4 = t1+t3; \ |
857 | p1 = t0+t3; \ |
858 | p2 = t1+t2; \ |
859 | p5 = (p3+p4)*f2f( 1.175875602f); \ |
860 | t0 = t0*f2f( 0.298631336f); \ |
861 | t1 = t1*f2f( 2.053119869f); \ |
862 | t2 = t2*f2f( 3.072711026f); \ |
863 | t3 = t3*f2f( 1.501321110f); \ |
864 | p1 = p5 + p1*f2f(-0.899976223f); \ |
865 | p2 = p5 + p2*f2f(-2.562915447f); \ |
866 | p3 = p3*f2f(-1.961570560f); \ |
867 | p4 = p4*f2f(-0.390180644f); \ |
868 | t3 += p1+p4; \ |
869 | t2 += p2+p3; \ |
870 | t1 += p2+p4; \ |
871 | t0 += p1+p3; |
872 | |
873 | #if !STBI_SIMD |
874 | // .344 seconds on 3*anemones.jpg |
875 | static void idct_block(uint8 *out, int out_stride, short data[64], uint8 *dequantize) |
876 | { |
877 | int i,val[64],*v=val; |
878 | uint8 *o,*dq = dequantize; |
879 | short *d = data; |
880 | |
881 | // columns |
882 | for (i=0; i < 8; ++i,++d,++dq, ++v) { |
883 | // if all zeroes, shortcut -- this avoids dequantizing 0s and IDCTing |
884 | if (d[ 8]==0 && d[16]==0 && d[24]==0 && d[32]==0 |
885 | && d[40]==0 && d[48]==0 && d[56]==0) { |
886 | // no shortcut 0 seconds |
887 | // (1|2|3|4|5|6|7)==0 0 seconds |
888 | // all separate -0.047 seconds |
889 | // 1 && 2|3 && 4|5 && 6|7: -0.047 seconds |
890 | int dcterm = d[0] * dq[0] << 2; |
891 | v[0] = v[8] = v[16] = v[24] = v[32] = v[40] = v[48] = v[56] = dcterm; |
892 | } else { |
893 | IDCT_1D(d[ 0]*dq[ 0],d[ 8]*dq[ 8],d[16]*dq[16],d[24]*dq[24], |
894 | d[32]*dq[32],d[40]*dq[40],d[48]*dq[48],d[56]*dq[56]) |
895 | // constants scaled things up by 1<<12; let's bring them back |
896 | // down, but keep 2 extra bits of precision |
897 | x0 += 512; x1 += 512; x2 += 512; x3 += 512; |
898 | v[ 0] = (x0+t3) >> 10; |
899 | v[56] = (x0-t3) >> 10; |
900 | v[ 8] = (x1+t2) >> 10; |
901 | v[48] = (x1-t2) >> 10; |
902 | v[16] = (x2+t1) >> 10; |
903 | v[40] = (x2-t1) >> 10; |
904 | v[24] = (x3+t0) >> 10; |
905 | v[32] = (x3-t0) >> 10; |
906 | } |
907 | } |
908 | |
909 | for (i=0, v=val, o=out; i < 8; ++i,v+=8,o+=out_stride) { |
910 | // no fast case since the first 1D IDCT spread components out |
911 | IDCT_1D(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7]) |
912 | // constants scaled things up by 1<<12, plus we had 1<<2 from first |
913 | // loop, plus horizontal and vertical each scale by sqrt(8) so together |
914 | // we've got an extra 1<<3, so 1<<17 total we need to remove. |
915 | x0 += 65536; x1 += 65536; x2 += 65536; x3 += 65536; |
916 | o[0] = clamp((x0+t3) >> 17); |
917 | o[7] = clamp((x0-t3) >> 17); |
918 | o[1] = clamp((x1+t2) >> 17); |
919 | o[6] = clamp((x1-t2) >> 17); |
920 | o[2] = clamp((x2+t1) >> 17); |
921 | o[5] = clamp((x2-t1) >> 17); |
922 | o[3] = clamp((x3+t0) >> 17); |
923 | o[4] = clamp((x3-t0) >> 17); |
924 | } |
925 | } |
926 | #else |
927 | static void idct_block(uint8 *out, int out_stride, short data[64], unsigned short *dequantize) |
928 | { |
929 | int i,val[64],*v=val; |
930 | uint8 *o; |
931 | unsigned short *dq = dequantize; |
932 | short *d = data; |
933 | |
934 | // columns |
935 | for (i=0; i < 8; ++i,++d,++dq, ++v) { |
936 | // if all zeroes, shortcut -- this avoids dequantizing 0s and IDCTing |
937 | if (d[ 8]==0 && d[16]==0 && d[24]==0 && d[32]==0 |
938 | && d[40]==0 && d[48]==0 && d[56]==0) { |
939 | // no shortcut 0 seconds |
940 | // (1|2|3|4|5|6|7)==0 0 seconds |
941 | // all separate -0.047 seconds |
942 | // 1 && 2|3 && 4|5 && 6|7: -0.047 seconds |
943 | int dcterm = d[0] * dq[0] << 2; |
944 | v[0] = v[8] = v[16] = v[24] = v[32] = v[40] = v[48] = v[56] = dcterm; |
945 | } else { |
946 | IDCT_1D(d[ 0]*dq[ 0],d[ 8]*dq[ 8],d[16]*dq[16],d[24]*dq[24], |
947 | d[32]*dq[32],d[40]*dq[40],d[48]*dq[48],d[56]*dq[56]) |
948 | // constants scaled things up by 1<<12; let's bring them back |
949 | // down, but keep 2 extra bits of precision |
950 | x0 += 512; x1 += 512; x2 += 512; x3 += 512; |
951 | v[ 0] = (x0+t3) >> 10; |
952 | v[56] = (x0-t3) >> 10; |
953 | v[ 8] = (x1+t2) >> 10; |
954 | v[48] = (x1-t2) >> 10; |
955 | v[16] = (x2+t1) >> 10; |
956 | v[40] = (x2-t1) >> 10; |
957 | v[24] = (x3+t0) >> 10; |
958 | v[32] = (x3-t0) >> 10; |
959 | } |
960 | } |
961 | |
962 | for (i=0, v=val, o=out; i < 8; ++i,v+=8,o+=out_stride) { |
963 | // no fast case since the first 1D IDCT spread components out |
964 | IDCT_1D(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7]) |
965 | // constants scaled things up by 1<<12, plus we had 1<<2 from first |
966 | // loop, plus horizontal and vertical each scale by sqrt(8) so together |
967 | // we've got an extra 1<<3, so 1<<17 total we need to remove. |
968 | x0 += 65536; x1 += 65536; x2 += 65536; x3 += 65536; |
969 | o[0] = clamp((x0+t3) >> 17); |
970 | o[7] = clamp((x0-t3) >> 17); |
971 | o[1] = clamp((x1+t2) >> 17); |
972 | o[6] = clamp((x1-t2) >> 17); |
973 | o[2] = clamp((x2+t1) >> 17); |
974 | o[5] = clamp((x2-t1) >> 17); |
975 | o[3] = clamp((x3+t0) >> 17); |
976 | o[4] = clamp((x3-t0) >> 17); |
977 | } |
978 | } |
979 | static stbi_idct_8x8 stbi_idct_installed = idct_block; |
980 | |
981 | extern void stbi_install_idct(stbi_idct_8x8 func) |
982 | { |
983 | stbi_idct_installed = func; |
984 | } |
985 | #endif |
986 | |
987 | #define MARKER_none 0xff |
988 | // if there's a pending marker from the entropy stream, return that |
989 | // otherwise, fetch from the stream and get a marker. if there's no |
990 | // marker, return 0xff, which is never a valid marker value |
991 | static uint8 get_marker(jpeg *j) |
992 | { |
993 | uint8 x; |
994 | if (j->marker != MARKER_none) { x = j->marker; j->marker = MARKER_none; return x; } |
995 | x = get8u(&j->s); |
996 | if (x != 0xff) return MARKER_none; |
997 | while (x == 0xff) |
998 | x = get8u(&j->s); |
999 | return x; |
1000 | } |
1001 | |
1002 | // in each scan, we'll have scan_n components, and the order |
1003 | // of the components is specified by order[] |
1004 | #define RESTART(x) ((x) >= 0xd0 && (x) <= 0xd7) |
1005 | |
1006 | // after a restart interval, reset the entropy decoder and |
1007 | // the dc prediction |
1008 | static void reset(jpeg *j) |
1009 | { |
1010 | j->code_bits = 0; |
1011 | j->code_buffer = 0; |
1012 | j->nomore = 0; |
1013 | j->img_comp[0].dc_pred = j->img_comp[1].dc_pred = j->img_comp[2].dc_pred = 0; |
1014 | j->marker = MARKER_none; |
1015 | j->todo = j->restart_interval ? j->restart_interval : 0x7fffffff; |
1016 | // no more than 1<<31 MCUs if no restart_interal? that's plenty safe, |
1017 | // since we don't even allow 1<<30 pixels |
1018 | } |
1019 | |
1020 | static int parse_entropy_coded_data(jpeg *z) |
1021 | { |
1022 | reset(z); |
1023 | if (z->scan_n == 1) { |
1024 | int i,j; |
1025 | #if STBI_SIMD |
1026 | __declspec(align(16)) |
1027 | #endif |
1028 | short data[64]; |
1029 | int n = z->order[0]; |
1030 | // non-interleaved data, we just need to process one block at a time, |
1031 | // in trivial scanline order |
1032 | // number of blocks to do just depends on how many actual "pixels" this |
1033 | // component has, independent of interleaved MCU blocking and such |
1034 | int w = (z->img_comp[n].x+7) >> 3; |
1035 | int h = (z->img_comp[n].y+7) >> 3; |
1036 | for (j=0; j < h; ++j) { |
1037 | for (i=0; i < w; ++i) { |
1038 | if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0; |
1039 | #if STBI_SIMD |
1040 | 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]); |
1041 | #else |
1042 | 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]); |
1043 | #endif |
1044 | // every data block is an MCU, so countdown the restart interval |
1045 | if (--z->todo <= 0) { |
1046 | if (z->code_bits < 24) grow_buffer_unsafe(z); |
1047 | // if it's NOT a restart, then just bail, so we get corrupt data |
1048 | // rather than no data |
1049 | if (!RESTART(z->marker)) return 1; |
1050 | reset(z); |
1051 | } |
1052 | } |
1053 | } |
1054 | } else { // interleaved! |
1055 | int i,j,k,x,y; |
1056 | short data[64]; |
1057 | for (j=0; j < z->img_mcu_y; ++j) { |
1058 | for (i=0; i < z->img_mcu_x; ++i) { |
1059 | // scan an interleaved mcu... process scan_n components in order |
1060 | for (k=0; k < z->scan_n; ++k) { |
1061 | int n = z->order[k]; |
1062 | // scan out an mcu's worth of this component; that's just determined |
1063 | // by the basic H and V specified for the component |
1064 | for (y=0; y < z->img_comp[n].v; ++y) { |
1065 | for (x=0; x < z->img_comp[n].h; ++x) { |
1066 | int x2 = (i*z->img_comp[n].h + x)*8; |
1067 | int y2 = (j*z->img_comp[n].v + y)*8; |
1068 | if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0; |
1069 | #if STBI_SIMD |
1070 | 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]); |
1071 | #else |
1072 | 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]); |
1073 | #endif |
1074 | } |
1075 | } |
1076 | } |
1077 | // after all interleaved components, that's an interleaved MCU, |
1078 | // so now count down the restart interval |
1079 | if (--z->todo <= 0) { |
1080 | if (z->code_bits < 24) grow_buffer_unsafe(z); |
1081 | // if it's NOT a restart, then just bail, so we get corrupt data |
1082 | // rather than no data |
1083 | if (!RESTART(z->marker)) return 1; |
1084 | reset(z); |
1085 | } |
1086 | } |
1087 | } |
1088 | } |
1089 | return 1; |
1090 | } |
1091 | |
1092 | static int process_marker(jpeg *z, int m) |
1093 | { |
1094 | int L; |
1095 | switch (m) { |
1096 | case MARKER_none: // no marker found |
1097 | return e("expected marker" ,"Corrupt JPEG" ); |
1098 | |
1099 | case 0xC2: // SOF - progressive |
1100 | return e("progressive jpeg" ,"JPEG format not supported (progressive)" ); |
1101 | |
1102 | case 0xDD: // DRI - specify restart interval |
1103 | if (get16(&z->s) != 4) return e("bad DRI len" ,"Corrupt JPEG" ); |
1104 | z->restart_interval = get16(&z->s); |
1105 | return 1; |
1106 | |
1107 | case 0xDB: // DQT - define quantization table |
1108 | L = get16(&z->s)-2; |
1109 | while (L > 0) { |
1110 | int q = get8(&z->s); |
1111 | int p = q >> 4; |
1112 | int t = q & 15,i; |
1113 | if (p != 0) return e("bad DQT type" ,"Corrupt JPEG" ); |
1114 | if (t > 3) return e("bad DQT table" ,"Corrupt JPEG" ); |
1115 | for (i=0; i < 64; ++i) |
1116 | z->dequant[t][dezigzag[i]] = get8u(&z->s); |
1117 | #if STBI_SIMD |
1118 | for (i=0; i < 64; ++i) |
1119 | z->dequant2[t][i] = dequant[t][i]; |
1120 | #endif |
1121 | L -= 65; |
1122 | } |
1123 | return L==0; |
1124 | |
1125 | case 0xC4: // DHT - define huffman table |
1126 | L = get16(&z->s)-2; |
1127 | while (L > 0) { |
1128 | uint8 *v; |
1129 | int sizes[16],i,m=0; |
1130 | int q = get8(&z->s); |
1131 | int tc = q >> 4; |
1132 | int th = q & 15; |
1133 | if (tc > 1 || th > 3) return e("bad DHT header" ,"Corrupt JPEG" ); |
1134 | for (i=0; i < 16; ++i) { |
1135 | sizes[i] = get8(&z->s); |
1136 | m += sizes[i]; |
1137 | } |
1138 | L -= 17; |
1139 | if (tc == 0) { |
1140 | if (!build_huffman(z->huff_dc+th, sizes)) return 0; |
1141 | v = z->huff_dc[th].values; |
1142 | } else { |
1143 | if (!build_huffman(z->huff_ac+th, sizes)) return 0; |
1144 | v = z->huff_ac[th].values; |
1145 | } |
1146 | for (i=0; i < m; ++i) |
1147 | v[i] = get8u(&z->s); |
1148 | L -= m; |
1149 | } |
1150 | return L==0; |
1151 | } |
1152 | // check for comment block or APP blocks |
1153 | if ((m >= 0xE0 && m <= 0xEF) || m == 0xFE) { |
1154 | skip(&z->s, get16(&z->s)-2); |
1155 | return 1; |
1156 | } |
1157 | return 0; |
1158 | } |
1159 | |
1160 | // after we see SOS |
1161 | static int (jpeg *z) |
1162 | { |
1163 | int i; |
1164 | int Ls = get16(&z->s); |
1165 | z->scan_n = get8(&z->s); |
1166 | 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" ); |
1167 | if (Ls != 6+2*z->scan_n) return e("bad SOS len" ,"Corrupt JPEG" ); |
1168 | for (i=0; i < z->scan_n; ++i) { |
1169 | int id = get8(&z->s), which; |
1170 | int q = get8(&z->s); |
1171 | for (which = 0; which < z->s.img_n; ++which) |
1172 | if (z->img_comp[which].id == id) |
1173 | break; |
1174 | if (which == z->s.img_n) return 0; |
1175 | z->img_comp[which].hd = q >> 4; if (z->img_comp[which].hd > 3) return e("bad DC huff" ,"Corrupt JPEG" ); |
1176 | z->img_comp[which].ha = q & 15; if (z->img_comp[which].ha > 3) return e("bad AC huff" ,"Corrupt JPEG" ); |
1177 | z->order[i] = which; |
1178 | } |
1179 | if (get8(&z->s) != 0) return e("bad SOS" ,"Corrupt JPEG" ); |
1180 | get8(&z->s); // should be 63, but might be 0 |
1181 | if (get8(&z->s) != 0) return e("bad SOS" ,"Corrupt JPEG" ); |
1182 | |
1183 | return 1; |
1184 | } |
1185 | |
1186 | static int (jpeg *z, int scan) |
1187 | { |
1188 | stbi *s = &z->s; |
1189 | int Lf,p,i,q, h_max=1,v_max=1,c; |
1190 | Lf = get16(s); if (Lf < 11) return e("bad SOF len" ,"Corrupt JPEG" ); // JPEG |
1191 | p = get8(s); if (p != 8) return e("only 8-bit" ,"JPEG format not supported: 8-bit only" ); // JPEG baseline |
1192 | 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 |
1193 | s->img_x = get16(s); if (s->img_x == 0) return e("0 width" ,"Corrupt JPEG" ); // JPEG requires |
1194 | c = get8(s); |
1195 | if (c != 3 && c != 1) return e("bad component count" ,"Corrupt JPEG" ); // JFIF requires |
1196 | s->img_n = c; |
1197 | for (i=0; i < c; ++i) { |
1198 | z->img_comp[i].data = NULL; |
1199 | z->img_comp[i].linebuf = NULL; |
1200 | } |
1201 | |
1202 | if (Lf != 8+3*s->img_n) return e("bad SOF len" ,"Corrupt JPEG" ); |
1203 | |
1204 | for (i=0; i < s->img_n; ++i) { |
1205 | z->img_comp[i].id = get8(s); |
1206 | if (z->img_comp[i].id != i+1) // JFIF requires |
1207 | if (z->img_comp[i].id != i) // some version of jpegtran outputs non-JFIF-compliant files! |
1208 | return e("bad component ID" ,"Corrupt JPEG" ); |
1209 | q = get8(s); |
1210 | 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" ); |
1211 | 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" ); |
1212 | z->img_comp[i].tq = get8(s); if (z->img_comp[i].tq > 3) return e("bad TQ" ,"Corrupt JPEG" ); |
1213 | } |
1214 | |
1215 | if (scan != SCAN_load) return 1; |
1216 | |
1217 | if ((1 << 30) / s->img_x / s->img_n < s->img_y) return e("too large" , "Image too large to decode" ); |
1218 | |
1219 | for (i=0; i < s->img_n; ++i) { |
1220 | if (z->img_comp[i].h > h_max) h_max = z->img_comp[i].h; |
1221 | if (z->img_comp[i].v > v_max) v_max = z->img_comp[i].v; |
1222 | } |
1223 | |
1224 | // compute interleaved mcu info |
1225 | z->img_h_max = h_max; |
1226 | z->img_v_max = v_max; |
1227 | z->img_mcu_w = h_max * 8; |
1228 | z->img_mcu_h = v_max * 8; |
1229 | z->img_mcu_x = (s->img_x + z->img_mcu_w-1) / z->img_mcu_w; |
1230 | z->img_mcu_y = (s->img_y + z->img_mcu_h-1) / z->img_mcu_h; |
1231 | |
1232 | for (i=0; i < s->img_n; ++i) { |
1233 | // number of effective pixels (e.g. for non-interleaved MCU) |
1234 | z->img_comp[i].x = (s->img_x * z->img_comp[i].h + h_max-1) / h_max; |
1235 | z->img_comp[i].y = (s->img_y * z->img_comp[i].v + v_max-1) / v_max; |
1236 | // to simplify generation, we'll allocate enough memory to decode |
1237 | // the bogus oversized data from using interleaved MCUs and their |
1238 | // big blocks (e.g. a 16x16 iMCU on an image of width 33); we won't |
1239 | // discard the extra data until colorspace conversion |
1240 | z->img_comp[i].w2 = z->img_mcu_x * z->img_comp[i].h * 8; |
1241 | z->img_comp[i].h2 = z->img_mcu_y * z->img_comp[i].v * 8; |
1242 | z->img_comp[i].raw_data = malloc(z->img_comp[i].w2 * z->img_comp[i].h2+15); |
1243 | if (z->img_comp[i].raw_data == NULL) { |
1244 | for(--i; i >= 0; --i) { |
1245 | free(z->img_comp[i].raw_data); |
1246 | z->img_comp[i].data = NULL; |
1247 | } |
1248 | return e("outofmem" , "Out of memory" ); |
1249 | } |
1250 | // align blocks for installable-idct using mmx/sse |
1251 | z->img_comp[i].data = (uint8*) (((size_t) z->img_comp[i].raw_data + 15) & ~15); |
1252 | z->img_comp[i].linebuf = NULL; |
1253 | } |
1254 | |
1255 | return 1; |
1256 | } |
1257 | |
1258 | // use comparisons since in some cases we handle more than one case (e.g. SOF) |
1259 | #define DNL(x) ((x) == 0xdc) |
1260 | #define SOI(x) ((x) == 0xd8) |
1261 | #define EOI(x) ((x) == 0xd9) |
1262 | #define SOF(x) ((x) == 0xc0 || (x) == 0xc1) |
1263 | #define SOS(x) ((x) == 0xda) |
1264 | |
1265 | static int (jpeg *z, int scan) |
1266 | { |
1267 | int m; |
1268 | z->marker = MARKER_none; // initialize cached marker to empty |
1269 | m = get_marker(z); |
1270 | if (!SOI(m)) return e("no SOI" ,"Corrupt JPEG" ); |
1271 | if (scan == SCAN_type) return 1; |
1272 | m = get_marker(z); |
1273 | while (!SOF(m)) { |
1274 | if (!process_marker(z,m)) return 0; |
1275 | m = get_marker(z); |
1276 | while (m == MARKER_none) { |
1277 | // some files have extra padding after their blocks, so ok, we'll scan |
1278 | if (at_eof(&z->s)) return e("no SOF" , "Corrupt JPEG" ); |
1279 | m = get_marker(z); |
1280 | } |
1281 | } |
1282 | if (!process_frame_header(z, scan)) return 0; |
1283 | return 1; |
1284 | } |
1285 | |
1286 | static int decode_jpeg_image(jpeg *j) |
1287 | { |
1288 | int m; |
1289 | j->restart_interval = 0; |
1290 | if (!decode_jpeg_header(j, SCAN_load)) return 0; |
1291 | m = get_marker(j); |
1292 | while (!EOI(m)) { |
1293 | if (SOS(m)) { |
1294 | if (!process_scan_header(j)) return 0; |
1295 | if (!parse_entropy_coded_data(j)) return 0; |
1296 | } else { |
1297 | if (!process_marker(j, m)) return 0; |
1298 | } |
1299 | m = get_marker(j); |
1300 | } |
1301 | return 1; |
1302 | } |
1303 | |
1304 | // static jfif-centered resampling (across block boundaries) |
1305 | |
1306 | typedef uint8 *(*resample_row_func)(uint8 *out, uint8 *in0, uint8 *in1, |
1307 | int w, int hs); |
1308 | |
1309 | #define div4(x) ((uint8) ((x) >> 2)) |
1310 | |
1311 | static uint8 *resample_row_1(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) |
1312 | { |
1313 | return in_near; |
1314 | } |
1315 | |
1316 | static uint8* resample_row_v_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) |
1317 | { |
1318 | // need to generate two samples vertically for every one in input |
1319 | int i; |
1320 | for (i=0; i < w; ++i) |
1321 | out[i] = div4(3*in_near[i] + in_far[i] + 2); |
1322 | return out; |
1323 | } |
1324 | |
1325 | static uint8* resample_row_h_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) |
1326 | { |
1327 | // need to generate two samples horizontally for every one in input |
1328 | int i; |
1329 | uint8 *input = in_near; |
1330 | if (w == 1) { |
1331 | // if only one sample, can't do any interpolation |
1332 | out[0] = out[1] = input[0]; |
1333 | return out; |
1334 | } |
1335 | |
1336 | out[0] = input[0]; |
1337 | out[1] = div4(input[0]*3 + input[1] + 2); |
1338 | for (i=1; i < w-1; ++i) { |
1339 | int n = 3*input[i]+2; |
1340 | out[i*2+0] = div4(n+input[i-1]); |
1341 | out[i*2+1] = div4(n+input[i+1]); |
1342 | } |
1343 | out[i*2+0] = div4(input[w-2]*3 + input[w-1] + 2); |
1344 | out[i*2+1] = input[w-1]; |
1345 | return out; |
1346 | } |
1347 | |
1348 | #define div16(x) ((uint8) ((x) >> 4)) |
1349 | |
1350 | static uint8 *resample_row_hv_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) |
1351 | { |
1352 | // need to generate 2x2 samples for every one in input |
1353 | int i,t0,t1; |
1354 | if (w == 1) { |
1355 | out[0] = out[1] = div4(3*in_near[0] + in_far[0] + 2); |
1356 | return out; |
1357 | } |
1358 | |
1359 | t1 = 3*in_near[0] + in_far[0]; |
1360 | out[0] = div4(t1+2); |
1361 | for (i=1; i < w; ++i) { |
1362 | t0 = t1; |
1363 | t1 = 3*in_near[i]+in_far[i]; |
1364 | out[i*2-1] = div16(3*t0 + t1 + 8); |
1365 | out[i*2 ] = div16(3*t1 + t0 + 8); |
1366 | } |
1367 | out[w*2-1] = div4(t1+2); |
1368 | return out; |
1369 | } |
1370 | |
1371 | static uint8 *resample_row_generic(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) |
1372 | { |
1373 | // resample with nearest-neighbor |
1374 | int i,j; |
1375 | for (i=0; i < w; ++i) |
1376 | for (j=0; j < hs; ++j) |
1377 | out[i*hs+j] = in_near[i]; |
1378 | return out; |
1379 | } |
1380 | |
1381 | #define float2fixed(x) ((int) ((x) * 65536 + 0.5)) |
1382 | |
1383 | // 0.38 seconds on 3*anemones.jpg (0.25 with processor = Pro) |
1384 | // VC6 without processor=Pro is generating multiple LEAs per multiply! |
1385 | static void YCbCr_to_RGB_row(uint8 *out, uint8 *y, uint8 *pcb, uint8 *pcr, int count, int step) |
1386 | { |
1387 | int i; |
1388 | for (i=0; i < count; ++i) { |
1389 | int y_fixed = (y[i] << 16) + 32768; // rounding |
1390 | int r,g,b; |
1391 | int cr = pcr[i] - 128; |
1392 | int cb = pcb[i] - 128; |
1393 | r = y_fixed + cr*float2fixed(1.40200f); |
1394 | g = y_fixed - cr*float2fixed(0.71414f) - cb*float2fixed(0.34414f); |
1395 | b = y_fixed + cb*float2fixed(1.77200f); |
1396 | r >>= 16; |
1397 | g >>= 16; |
1398 | b >>= 16; |
1399 | if ((unsigned) r > 255) { if (r < 0) r = 0; else r = 255; } |
1400 | if ((unsigned) g > 255) { if (g < 0) g = 0; else g = 255; } |
1401 | if ((unsigned) b > 255) { if (b < 0) b = 0; else b = 255; } |
1402 | out[0] = (uint8)r; |
1403 | out[1] = (uint8)g; |
1404 | out[2] = (uint8)b; |
1405 | out[3] = 255; |
1406 | out += step; |
1407 | } |
1408 | } |
1409 | |
1410 | #if STBI_SIMD |
1411 | static stbi_YCbCr_to_RGB_run stbi_YCbCr_installed = YCbCr_to_RGB_row; |
1412 | |
1413 | void stbi_install_YCbCr_to_RGB(stbi_YCbCr_to_RGB_run func) |
1414 | { |
1415 | stbi_YCbCr_installed = func; |
1416 | } |
1417 | #endif |
1418 | |
1419 | |
1420 | // clean up the temporary component buffers |
1421 | static void cleanup_jpeg(jpeg *j) |
1422 | { |
1423 | int i; |
1424 | for (i=0; i < j->s.img_n; ++i) { |
1425 | if (j->img_comp[i].data) { |
1426 | free(j->img_comp[i].raw_data); |
1427 | j->img_comp[i].data = NULL; |
1428 | } |
1429 | if (j->img_comp[i].linebuf) { |
1430 | free(j->img_comp[i].linebuf); |
1431 | j->img_comp[i].linebuf = NULL; |
1432 | } |
1433 | } |
1434 | } |
1435 | |
1436 | typedef struct |
1437 | { |
1438 | resample_row_func resample; |
1439 | uint8 *line0,*line1; |
1440 | int hs,vs; // expansion factor in each axis |
1441 | int w_lores; // horizontal pixels pre-expansion |
1442 | int ystep; // how far through vertical expansion we are |
1443 | int ypos; // which pre-expansion row we're on |
1444 | } stbi_resample; |
1445 | |
1446 | static uint8 *load_jpeg_image(jpeg *z, int *out_x, int *out_y, int *comp, int req_comp) |
1447 | { |
1448 | int n, decode_n; |
1449 | // validate req_comp |
1450 | if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp" , "Internal error" ); |
1451 | z->s.img_n = 0; |
1452 | |
1453 | // load a jpeg image from whichever source |
1454 | if (!decode_jpeg_image(z)) { cleanup_jpeg(z); return NULL; } |
1455 | |
1456 | // determine actual number of components to generate |
1457 | n = req_comp ? req_comp : z->s.img_n; |
1458 | |
1459 | if (z->s.img_n == 3 && n < 3) |
1460 | decode_n = 1; |
1461 | else |
1462 | decode_n = z->s.img_n; |
1463 | |
1464 | // resample and color-convert |
1465 | { |
1466 | int k; |
1467 | uint i,j; |
1468 | uint8 *output; |
1469 | uint8 *coutput[4]; |
1470 | |
1471 | stbi_resample res_comp[4]; |
1472 | |
1473 | for (k=0; k < decode_n; ++k) { |
1474 | stbi_resample *r = &res_comp[k]; |
1475 | |
1476 | // allocate line buffer big enough for upsampling off the edges |
1477 | // with upsample factor of 4 |
1478 | z->img_comp[k].linebuf = (uint8 *) malloc(z->s.img_x + 3); |
1479 | if (!z->img_comp[k].linebuf) { cleanup_jpeg(z); return epuc("outofmem" , "Out of memory" ); } |
1480 | |
1481 | r->hs = z->img_h_max / z->img_comp[k].h; |
1482 | r->vs = z->img_v_max / z->img_comp[k].v; |
1483 | r->ystep = r->vs >> 1; |
1484 | r->w_lores = (z->s.img_x + r->hs-1) / r->hs; |
1485 | r->ypos = 0; |
1486 | r->line0 = r->line1 = z->img_comp[k].data; |
1487 | |
1488 | if (r->hs == 1 && r->vs == 1) r->resample = resample_row_1; |
1489 | else if (r->hs == 1 && r->vs == 2) r->resample = resample_row_v_2; |
1490 | else if (r->hs == 2 && r->vs == 1) r->resample = resample_row_h_2; |
1491 | else if (r->hs == 2 && r->vs == 2) r->resample = resample_row_hv_2; |
1492 | else r->resample = resample_row_generic; |
1493 | } |
1494 | |
1495 | // can't error after this so, this is safe |
1496 | output = (uint8 *) malloc(n * z->s.img_x * z->s.img_y + 1); |
1497 | if (!output) { cleanup_jpeg(z); return epuc("outofmem" , "Out of memory" ); } |
1498 | |
1499 | // now go ahead and resample |
1500 | for (j=0; j < z->s.img_y; ++j) { |
1501 | uint8 *out = output + n * z->s.img_x * j; |
1502 | for (k=0; k < decode_n; ++k) { |
1503 | stbi_resample *r = &res_comp[k]; |
1504 | int y_bot = r->ystep >= (r->vs >> 1); |
1505 | coutput[k] = r->resample(z->img_comp[k].linebuf, |
1506 | y_bot ? r->line1 : r->line0, |
1507 | y_bot ? r->line0 : r->line1, |
1508 | r->w_lores, r->hs); |
1509 | if (++r->ystep >= r->vs) { |
1510 | r->ystep = 0; |
1511 | r->line0 = r->line1; |
1512 | if (++r->ypos < z->img_comp[k].y) |
1513 | r->line1 += z->img_comp[k].w2; |
1514 | } |
1515 | } |
1516 | if (n >= 3) { |
1517 | uint8 *y = coutput[0]; |
1518 | if (z->s.img_n == 3) { |
1519 | #if STBI_SIMD |
1520 | stbi_YCbCr_installed(out, y, coutput[1], coutput[2], z->s.img_x, n); |
1521 | #else |
1522 | YCbCr_to_RGB_row(out, y, coutput[1], coutput[2], z->s.img_x, n); |
1523 | #endif |
1524 | } else |
1525 | for (i=0; i < z->s.img_x; ++i) { |
1526 | out[0] = out[1] = out[2] = y[i]; |
1527 | out[3] = 255; // not used if n==3 |
1528 | out += n; |
1529 | } |
1530 | } else { |
1531 | uint8 *y = coutput[0]; |
1532 | if (n == 1) |
1533 | for (i=0; i < z->s.img_x; ++i) out[i] = y[i]; |
1534 | else |
1535 | for (i=0; i < z->s.img_x; ++i) *out++ = y[i], *out++ = 255; |
1536 | } |
1537 | } |
1538 | cleanup_jpeg(z); |
1539 | *out_x = z->s.img_x; |
1540 | *out_y = z->s.img_y; |
1541 | if (comp) *comp = z->s.img_n; // report original components, not output |
1542 | return output; |
1543 | } |
1544 | } |
1545 | |
1546 | #ifndef STBI_NO_STDIO |
1547 | unsigned char *stbi_jpeg_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) |
1548 | { |
1549 | jpeg j; |
1550 | start_file(&j.s, f); |
1551 | return load_jpeg_image(&j, x,y,comp,req_comp); |
1552 | } |
1553 | |
1554 | unsigned char *stbi_jpeg_load(char const *filename, int *x, int *y, int *comp, int req_comp) |
1555 | { |
1556 | unsigned char *data; |
1557 | FILE *f = fopen(filename, "rb" ); |
1558 | if (!f) return NULL; |
1559 | data = stbi_jpeg_load_from_file(f,x,y,comp,req_comp); |
1560 | fclose(f); |
1561 | return data; |
1562 | } |
1563 | #endif |
1564 | |
1565 | unsigned char *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) |
1566 | { |
1567 | jpeg j; |
1568 | start_mem(&j.s, buffer,len); |
1569 | return load_jpeg_image(&j, x,y,comp,req_comp); |
1570 | } |
1571 | |
1572 | #ifndef STBI_NO_STDIO |
1573 | int stbi_jpeg_test_file(FILE *f) |
1574 | { |
1575 | int n,r; |
1576 | jpeg j; |
1577 | n = ftell(f); |
1578 | start_file(&j.s, f); |
1579 | r = decode_jpeg_header(&j, SCAN_type); |
1580 | fseek(f,n,SEEK_SET); |
1581 | return r; |
1582 | } |
1583 | #endif |
1584 | |
1585 | int stbi_jpeg_test_memory(stbi_uc const *buffer, int len) |
1586 | { |
1587 | jpeg j; |
1588 | start_mem(&j.s, buffer,len); |
1589 | return decode_jpeg_header(&j, SCAN_type); |
1590 | } |
1591 | |
1592 | // @TODO: |
1593 | #ifndef STBI_NO_STDIO |
1594 | extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp); |
1595 | extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp); |
1596 | #endif |
1597 | extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); |
1598 | |
1599 | // public domain zlib decode v0.2 Sean Barrett 2006-11-18 |
1600 | // simple implementation |
1601 | // - all input must be provided in an upfront buffer |
1602 | // - all output is written to a single output buffer (can malloc/realloc) |
1603 | // performance |
1604 | // - fast huffman |
1605 | |
1606 | // fast-way is faster to check than jpeg huffman, but slow way is slower |
1607 | #define ZFAST_BITS 9 // accelerate all cases in default tables |
1608 | #define ZFAST_MASK ((1 << ZFAST_BITS) - 1) |
1609 | |
1610 | // zlib-style huffman encoding |
1611 | // (jpegs packs from left, zlib from right, so can't share code) |
1612 | typedef struct |
1613 | { |
1614 | uint16 fast[1 << ZFAST_BITS]; |
1615 | uint16 firstcode[16]; |
1616 | int maxcode[17]; |
1617 | uint16 firstsymbol[16]; |
1618 | uint8 size[288]; |
1619 | uint16 value[288]; |
1620 | } zhuffman; |
1621 | |
1622 | __forceinline static int bitreverse16(int n) |
1623 | { |
1624 | n = ((n & 0xAAAA) >> 1) | ((n & 0x5555) << 1); |
1625 | n = ((n & 0xCCCC) >> 2) | ((n & 0x3333) << 2); |
1626 | n = ((n & 0xF0F0) >> 4) | ((n & 0x0F0F) << 4); |
1627 | n = ((n & 0xFF00) >> 8) | ((n & 0x00FF) << 8); |
1628 | return n; |
1629 | } |
1630 | |
1631 | __forceinline static int bit_reverse(int v, int bits) |
1632 | { |
1633 | assert(bits <= 16); |
1634 | // to bit reverse n bits, reverse 16 and shift |
1635 | // e.g. 11 bits, bit reverse and shift away 5 |
1636 | return bitreverse16(v) >> (16-bits); |
1637 | } |
1638 | |
1639 | static int zbuild_huffman(zhuffman *z, uint8 *sizelist, int num) |
1640 | { |
1641 | int i,k=0; |
1642 | int code, next_code[16], sizes[17]; |
1643 | |
1644 | // DEFLATE spec for generating codes |
1645 | memset(sizes, 0, sizeof(sizes)); |
1646 | memset(z->fast, 255, sizeof(z->fast)); |
1647 | for (i=0; i < num; ++i) |
1648 | ++sizes[sizelist[i]]; |
1649 | sizes[0] = 0; |
1650 | for (i=1; i < 16; ++i) |
1651 | assert(sizes[i] <= (1 << i)); |
1652 | code = 0; |
1653 | for (i=1; i < 16; ++i) { |
1654 | next_code[i] = code; |
1655 | z->firstcode[i] = (uint16) code; |
1656 | z->firstsymbol[i] = (uint16) k; |
1657 | code = (code + sizes[i]); |
1658 | if (sizes[i]) |
1659 | if (code-1 >= (1 << i)) return e("bad codelengths" ,"Corrupt JPEG" ); |
1660 | z->maxcode[i] = code << (16-i); // preshift for inner loop |
1661 | code <<= 1; |
1662 | k += sizes[i]; |
1663 | } |
1664 | z->maxcode[16] = 0x10000; // sentinel |
1665 | for (i=0; i < num; ++i) { |
1666 | int s = sizelist[i]; |
1667 | if (s) { |
1668 | int c = next_code[s] - z->firstcode[s] + z->firstsymbol[s]; |
1669 | z->size[c] = (uint8)s; |
1670 | z->value[c] = (uint16)i; |
1671 | if (s <= ZFAST_BITS) { |
1672 | int k = bit_reverse(next_code[s],s); |
1673 | while (k < (1 << ZFAST_BITS)) { |
1674 | z->fast[k] = (uint16) c; |
1675 | k += (1 << s); |
1676 | } |
1677 | } |
1678 | ++next_code[s]; |
1679 | } |
1680 | } |
1681 | return 1; |
1682 | } |
1683 | |
1684 | // zlib-from-memory implementation for PNG reading |
1685 | // because PNG allows splitting the zlib stream arbitrarily, |
1686 | // and it's annoying structurally to have PNG call ZLIB call PNG, |
1687 | // we require PNG read all the IDATs and combine them into a single |
1688 | // memory buffer |
1689 | |
1690 | typedef struct |
1691 | { |
1692 | uint8 *zbuffer, *zbuffer_end; |
1693 | int num_bits; |
1694 | uint32 code_buffer; |
1695 | |
1696 | char *zout; |
1697 | char *zout_start; |
1698 | char *zout_end; |
1699 | int z_expandable; |
1700 | |
1701 | zhuffman z_length, z_distance; |
1702 | } zbuf; |
1703 | |
1704 | __forceinline static int zget8(zbuf *z) |
1705 | { |
1706 | if (z->zbuffer >= z->zbuffer_end) return 0; |
1707 | return *z->zbuffer++; |
1708 | } |
1709 | |
1710 | static void fill_bits(zbuf *z) |
1711 | { |
1712 | do { |
1713 | assert(z->code_buffer < (1U << z->num_bits)); |
1714 | z->code_buffer |= zget8(z) << z->num_bits; |
1715 | z->num_bits += 8; |
1716 | } while (z->num_bits <= 24); |
1717 | } |
1718 | |
1719 | __forceinline static unsigned int zreceive(zbuf *z, int n) |
1720 | { |
1721 | unsigned int k; |
1722 | if (z->num_bits < n) fill_bits(z); |
1723 | k = z->code_buffer & ((1 << n) - 1); |
1724 | z->code_buffer >>= n; |
1725 | z->num_bits -= n; |
1726 | return k; |
1727 | } |
1728 | |
1729 | __forceinline static int zhuffman_decode(zbuf *a, zhuffman *z) |
1730 | { |
1731 | int b,s,k; |
1732 | if (a->num_bits < 16) fill_bits(a); |
1733 | b = z->fast[a->code_buffer & ZFAST_MASK]; |
1734 | if (b < 0xffff) { |
1735 | s = z->size[b]; |
1736 | a->code_buffer >>= s; |
1737 | a->num_bits -= s; |
1738 | return z->value[b]; |
1739 | } |
1740 | |
1741 | // not resolved by fast table, so compute it the slow way |
1742 | // use jpeg approach, which requires MSbits at top |
1743 | k = bit_reverse(a->code_buffer, 16); |
1744 | for (s=ZFAST_BITS+1; ; ++s) |
1745 | if (k < z->maxcode[s]) |
1746 | break; |
1747 | if (s == 16) return -1; // invalid code! |
1748 | // code size is s, so: |
1749 | b = (k >> (16-s)) - z->firstcode[s] + z->firstsymbol[s]; |
1750 | assert(z->size[b] == s); |
1751 | a->code_buffer >>= s; |
1752 | a->num_bits -= s; |
1753 | return z->value[b]; |
1754 | } |
1755 | |
1756 | static int expand(zbuf *z, int n) // need to make room for n bytes |
1757 | { |
1758 | char *q; |
1759 | int cur, limit; |
1760 | if (!z->z_expandable) return e("output buffer limit" ,"Corrupt PNG" ); |
1761 | cur = (int) (z->zout - z->zout_start); |
1762 | limit = (int) (z->zout_end - z->zout_start); |
1763 | while (cur + n > limit) |
1764 | limit *= 2; |
1765 | q = (char *) realloc(z->zout_start, limit); |
1766 | if (q == NULL) return e("outofmem" , "Out of memory" ); |
1767 | z->zout_start = q; |
1768 | z->zout = q + cur; |
1769 | z->zout_end = q + limit; |
1770 | return 1; |
1771 | } |
1772 | |
1773 | static int length_base[31] = { |
1774 | 3,4,5,6,7,8,9,10,11,13, |
1775 | 15,17,19,23,27,31,35,43,51,59, |
1776 | 67,83,99,115,131,163,195,227,258,0,0 }; |
1777 | |
1778 | static int [31]= |
1779 | { 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 }; |
1780 | |
1781 | static int dist_base[32] = { 1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193, |
1782 | 257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577,0,0}; |
1783 | |
1784 | static int [32] = |
1785 | { 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}; |
1786 | |
1787 | static int parse_huffman_block(zbuf *a) |
1788 | { |
1789 | for(;;) { |
1790 | int z = zhuffman_decode(a, &a->z_length); |
1791 | if (z < 256) { |
1792 | if (z < 0) return e("bad huffman code" ,"Corrupt PNG" ); // error in huffman codes |
1793 | if (a->zout >= a->zout_end) if (!expand(a, 1)) return 0; |
1794 | *a->zout++ = (char) z; |
1795 | } else { |
1796 | uint8 *p; |
1797 | int len,dist; |
1798 | if (z == 256) return 1; |
1799 | z -= 257; |
1800 | len = length_base[z]; |
1801 | if (length_extra[z]) len += zreceive(a, length_extra[z]); |
1802 | z = zhuffman_decode(a, &a->z_distance); |
1803 | if (z < 0) return e("bad huffman code" ,"Corrupt PNG" ); |
1804 | dist = dist_base[z]; |
1805 | if (dist_extra[z]) dist += zreceive(a, dist_extra[z]); |
1806 | if (a->zout - a->zout_start < dist) return e("bad dist" ,"Corrupt PNG" ); |
1807 | if (a->zout + len > a->zout_end) if (!expand(a, len)) return 0; |
1808 | p = (uint8 *) (a->zout - dist); |
1809 | while (len--) |
1810 | *a->zout++ = *p++; |
1811 | } |
1812 | } |
1813 | } |
1814 | |
1815 | static int compute_huffman_codes(zbuf *a) |
1816 | { |
1817 | static uint8 length_dezigzag[19] = { 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 }; |
1818 | static zhuffman z_codelength; // static just to save stack space |
1819 | uint8 lencodes[286+32+137];//padding for maximum single op |
1820 | uint8 codelength_sizes[19]; |
1821 | int i,n; |
1822 | |
1823 | int hlit = zreceive(a,5) + 257; |
1824 | int hdist = zreceive(a,5) + 1; |
1825 | int hclen = zreceive(a,4) + 4; |
1826 | |
1827 | memset(codelength_sizes, 0, sizeof(codelength_sizes)); |
1828 | for (i=0; i < hclen; ++i) { |
1829 | int s = zreceive(a,3); |
1830 | codelength_sizes[length_dezigzag[i]] = (uint8) s; |
1831 | } |
1832 | if (!zbuild_huffman(&z_codelength, codelength_sizes, 19)) return 0; |
1833 | |
1834 | n = 0; |
1835 | while (n < hlit + hdist) { |
1836 | int c = zhuffman_decode(a, &z_codelength); |
1837 | assert(c >= 0 && c < 19); |
1838 | if (c < 16) |
1839 | lencodes[n++] = (uint8) c; |
1840 | else if (c == 16) { |
1841 | c = zreceive(a,2)+3; |
1842 | memset(lencodes+n, lencodes[n-1], c); |
1843 | n += c; |
1844 | } else if (c == 17) { |
1845 | c = zreceive(a,3)+3; |
1846 | memset(lencodes+n, 0, c); |
1847 | n += c; |
1848 | } else { |
1849 | assert(c == 18); |
1850 | c = zreceive(a,7)+11; |
1851 | memset(lencodes+n, 0, c); |
1852 | n += c; |
1853 | } |
1854 | } |
1855 | if (n != hlit+hdist) return e("bad codelengths" ,"Corrupt PNG" ); |
1856 | if (!zbuild_huffman(&a->z_length, lencodes, hlit)) return 0; |
1857 | if (!zbuild_huffman(&a->z_distance, lencodes+hlit, hdist)) return 0; |
1858 | return 1; |
1859 | } |
1860 | |
1861 | static int parse_uncompressed_block(zbuf *a) |
1862 | { |
1863 | uint8 [4]; |
1864 | int len,nlen,k; |
1865 | if (a->num_bits & 7) |
1866 | zreceive(a, a->num_bits & 7); // discard |
1867 | // drain the bit-packed data into header |
1868 | k = 0; |
1869 | while (a->num_bits > 0) { |
1870 | header[k++] = (uint8) (a->code_buffer & 255); // wtf this warns? |
1871 | a->code_buffer >>= 8; |
1872 | a->num_bits -= 8; |
1873 | } |
1874 | assert(a->num_bits == 0); |
1875 | // now fill header the normal way |
1876 | while (k < 4) |
1877 | header[k++] = (uint8) zget8(a); |
1878 | len = header[1] * 256 + header[0]; |
1879 | nlen = header[3] * 256 + header[2]; |
1880 | if (nlen != (len ^ 0xffff)) return e("zlib corrupt" ,"Corrupt PNG" ); |
1881 | if (a->zbuffer + len > a->zbuffer_end) return e("read past buffer" ,"Corrupt PNG" ); |
1882 | if (a->zout + len > a->zout_end) |
1883 | if (!expand(a, len)) return 0; |
1884 | memcpy(a->zout, a->zbuffer, len); |
1885 | a->zbuffer += len; |
1886 | a->zout += len; |
1887 | return 1; |
1888 | } |
1889 | |
1890 | static int (zbuf *a) |
1891 | { |
1892 | int cmf = zget8(a); |
1893 | int cm = cmf & 15; |
1894 | /* int cinfo = cmf >> 4; */ |
1895 | int flg = zget8(a); |
1896 | if ((cmf*256+flg) % 31 != 0) return e("bad zlib header" ,"Corrupt PNG" ); // zlib spec |
1897 | if (flg & 32) return e("no preset dict" ,"Corrupt PNG" ); // preset dictionary not allowed in png |
1898 | if (cm != 8) return e("bad compression" ,"Corrupt PNG" ); // DEFLATE required for png |
1899 | // window = 1 << (8 + cinfo)... but who cares, we fully buffer output |
1900 | return 1; |
1901 | } |
1902 | |
1903 | // @TODO: should statically initialize these for optimal thread safety |
1904 | static uint8 default_length[288], default_distance[32]; |
1905 | static void init_defaults(void) |
1906 | { |
1907 | int i; // use <= to match clearly with spec |
1908 | for (i=0; i <= 143; ++i) default_length[i] = 8; |
1909 | for ( ; i <= 255; ++i) default_length[i] = 9; |
1910 | for ( ; i <= 279; ++i) default_length[i] = 7; |
1911 | for ( ; i <= 287; ++i) default_length[i] = 8; |
1912 | |
1913 | for (i=0; i <= 31; ++i) default_distance[i] = 5; |
1914 | } |
1915 | |
1916 | static int parse_zlib(zbuf *a, int ) |
1917 | { |
1918 | int final, type; |
1919 | if (parse_header) |
1920 | if (!parse_zlib_header(a)) return 0; |
1921 | a->num_bits = 0; |
1922 | a->code_buffer = 0; |
1923 | do { |
1924 | final = zreceive(a,1); |
1925 | type = zreceive(a,2); |
1926 | if (type == 0) { |
1927 | if (!parse_uncompressed_block(a)) return 0; |
1928 | } else if (type == 3) { |
1929 | return 0; |
1930 | } else { |
1931 | if (type == 1) { |
1932 | // use fixed code lengths |
1933 | if (!default_distance[31]) init_defaults(); |
1934 | if (!zbuild_huffman(&a->z_length , default_length , 288)) return 0; |
1935 | if (!zbuild_huffman(&a->z_distance, default_distance, 32)) return 0; |
1936 | } else { |
1937 | if (!compute_huffman_codes(a)) return 0; |
1938 | } |
1939 | if (!parse_huffman_block(a)) return 0; |
1940 | } |
1941 | } while (!final); |
1942 | return 1; |
1943 | } |
1944 | |
1945 | static int do_zlib(zbuf *a, char *obuf, int olen, int exp, int ) |
1946 | { |
1947 | a->zout_start = obuf; |
1948 | a->zout = obuf; |
1949 | a->zout_end = obuf + olen; |
1950 | a->z_expandable = exp; |
1951 | |
1952 | return parse_zlib(a, parse_header); |
1953 | } |
1954 | |
1955 | char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen) |
1956 | { |
1957 | zbuf a; |
1958 | char *p = (char *) malloc(initial_size); |
1959 | if (p == NULL) return NULL; |
1960 | a.zbuffer = (uint8 *) buffer; |
1961 | a.zbuffer_end = (uint8 *) buffer + len; |
1962 | if (do_zlib(&a, p, initial_size, 1, 1)) { |
1963 | if (outlen) *outlen = (int) (a.zout - a.zout_start); |
1964 | return a.zout_start; |
1965 | } else { |
1966 | free(a.zout_start); |
1967 | return NULL; |
1968 | } |
1969 | } |
1970 | |
1971 | char *stbi_zlib_decode_malloc(char const *buffer, int len, int *outlen) |
1972 | { |
1973 | return stbi_zlib_decode_malloc_guesssize(buffer, len, 16384, outlen); |
1974 | } |
1975 | |
1976 | int stbi_zlib_decode_buffer(char *obuffer, int olen, char const *ibuffer, int ilen) |
1977 | { |
1978 | zbuf a; |
1979 | a.zbuffer = (uint8 *) ibuffer; |
1980 | a.zbuffer_end = (uint8 *) ibuffer + ilen; |
1981 | if (do_zlib(&a, obuffer, olen, 0, 1)) |
1982 | return (int) (a.zout - a.zout_start); |
1983 | else |
1984 | return -1; |
1985 | } |
1986 | |
1987 | char *(char const *buffer, int len, int *outlen) |
1988 | { |
1989 | zbuf a; |
1990 | char *p = (char *) malloc(16384); |
1991 | if (p == NULL) return NULL; |
1992 | a.zbuffer = (uint8 *) buffer; |
1993 | a.zbuffer_end = (uint8 *) buffer+len; |
1994 | if (do_zlib(&a, p, 16384, 1, 0)) { |
1995 | if (outlen) *outlen = (int) (a.zout - a.zout_start); |
1996 | return a.zout_start; |
1997 | } else { |
1998 | free(a.zout_start); |
1999 | return NULL; |
2000 | } |
2001 | } |
2002 | |
2003 | int (char *obuffer, int olen, const char *ibuffer, int ilen) |
2004 | { |
2005 | zbuf a; |
2006 | a.zbuffer = (uint8 *) ibuffer; |
2007 | a.zbuffer_end = (uint8 *) ibuffer + ilen; |
2008 | if (do_zlib(&a, obuffer, olen, 0, 0)) |
2009 | return (int) (a.zout - a.zout_start); |
2010 | else |
2011 | return -1; |
2012 | } |
2013 | |
2014 | // public domain "baseline" PNG decoder v0.10 Sean Barrett 2006-11-18 |
2015 | // simple implementation |
2016 | // - only 8-bit samples |
2017 | // - no CRC checking |
2018 | // - allocates lots of intermediate memory |
2019 | // - avoids problem of streaming data between subsystems |
2020 | // - avoids explicit window management |
2021 | // performance |
2022 | // - uses stb_zlib, a PD zlib implementation with fast huffman decoding |
2023 | |
2024 | |
2025 | typedef struct |
2026 | { |
2027 | uint32 length; |
2028 | uint32 type; |
2029 | } chunk; |
2030 | |
2031 | #define PNG_TYPE(a,b,c,d) (((a) << 24) + ((b) << 16) + ((c) << 8) + (d)) |
2032 | |
2033 | static chunk (stbi *s) |
2034 | { |
2035 | chunk c; |
2036 | c.length = get32(s); |
2037 | c.type = get32(s); |
2038 | return c; |
2039 | } |
2040 | |
2041 | static int (stbi *s) |
2042 | { |
2043 | static uint8 png_sig[8] = { 137,80,78,71,13,10,26,10 }; |
2044 | int i; |
2045 | for (i=0; i < 8; ++i) |
2046 | if (get8(s) != png_sig[i]) return e("bad png sig" ,"Not a PNG" ); |
2047 | return 1; |
2048 | } |
2049 | |
2050 | typedef struct |
2051 | { |
2052 | stbi s; |
2053 | uint8 *idata, *expanded, *out; |
2054 | } png; |
2055 | |
2056 | |
2057 | enum { |
2058 | F_none=0, F_sub=1, F_up=2, F_avg=3, F_paeth=4, |
2059 | F_avg_first, F_paeth_first, |
2060 | }; |
2061 | |
2062 | static uint8 first_row_filter[5] = |
2063 | { |
2064 | F_none, F_sub, F_none, F_avg_first, F_paeth_first |
2065 | }; |
2066 | |
2067 | static int paeth(int a, int b, int c) |
2068 | { |
2069 | int p = a + b - c; |
2070 | int pa = abs(p-a); |
2071 | int pb = abs(p-b); |
2072 | int pc = abs(p-c); |
2073 | if (pa <= pb && pa <= pc) return a; |
2074 | if (pb <= pc) return b; |
2075 | return c; |
2076 | } |
2077 | |
2078 | // create the png data from post-deflated data |
2079 | static int create_png_image(png *a, uint8 *raw, uint32 raw_len, int out_n) |
2080 | { |
2081 | stbi *s = &a->s; |
2082 | uint32 i,j,stride = s->img_x*out_n; |
2083 | int k; |
2084 | int img_n = s->img_n; // copy it into a local for later |
2085 | assert(out_n == s->img_n || out_n == s->img_n+1); |
2086 | a->out = (uint8 *) malloc(s->img_x * s->img_y * out_n); |
2087 | if (!a->out) return e("outofmem" , "Out of memory" ); |
2088 | if (raw_len != (img_n * s->img_x + 1) * s->img_y) return e("not enough pixels" ,"Corrupt PNG" ); |
2089 | for (j=0; j < s->img_y; ++j) { |
2090 | uint8 *cur = a->out + stride*j; |
2091 | uint8 *prior = cur - stride; |
2092 | int filter = *raw++; |
2093 | if (filter > 4) return e("invalid filter" ,"Corrupt PNG" ); |
2094 | // if first row, use special filter that doesn't sample previous row |
2095 | if (j == 0) filter = first_row_filter[filter]; |
2096 | // handle first pixel explicitly |
2097 | for (k=0; k < img_n; ++k) { |
2098 | switch(filter) { |
2099 | case F_none : cur[k] = raw[k]; break; |
2100 | case F_sub : cur[k] = raw[k]; break; |
2101 | case F_up : cur[k] = raw[k] + prior[k]; break; |
2102 | case F_avg : cur[k] = raw[k] + (prior[k]>>1); break; |
2103 | case F_paeth : cur[k] = (uint8) (raw[k] + paeth(0,prior[k],0)); break; |
2104 | case F_avg_first : cur[k] = raw[k]; break; |
2105 | case F_paeth_first: cur[k] = raw[k]; break; |
2106 | } |
2107 | } |
2108 | if (img_n != out_n) cur[img_n] = 255; |
2109 | raw += img_n; |
2110 | cur += out_n; |
2111 | prior += out_n; |
2112 | // this is a little gross, so that we don't switch per-pixel or per-component |
2113 | if (img_n == out_n) { |
2114 | #define CASE(f) \ |
2115 | case f: \ |
2116 | for (i=s->img_x-1; i >= 1; --i, raw+=img_n,cur+=img_n,prior+=img_n) \ |
2117 | for (k=0; k < img_n; ++k) |
2118 | switch(filter) { |
2119 | CASE(F_none) cur[k] = raw[k]; break; |
2120 | CASE(F_sub) cur[k] = raw[k] + cur[k-img_n]; break; |
2121 | CASE(F_up) cur[k] = raw[k] + prior[k]; break; |
2122 | CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-img_n])>>1); break; |
2123 | CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],prior[k],prior[k-img_n])); break; |
2124 | CASE(F_avg_first) cur[k] = raw[k] + (cur[k-img_n] >> 1); break; |
2125 | CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],0,0)); break; |
2126 | } |
2127 | #undef CASE |
2128 | } else { |
2129 | assert(img_n+1 == out_n); |
2130 | #define CASE(f) \ |
2131 | case f: \ |
2132 | for (i=s->img_x-1; i >= 1; --i, cur[img_n]=255,raw+=img_n,cur+=out_n,prior+=out_n) \ |
2133 | for (k=0; k < img_n; ++k) |
2134 | switch(filter) { |
2135 | CASE(F_none) cur[k] = raw[k]; break; |
2136 | CASE(F_sub) cur[k] = raw[k] + cur[k-out_n]; break; |
2137 | CASE(F_up) cur[k] = raw[k] + prior[k]; break; |
2138 | CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-out_n])>>1); break; |
2139 | CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],prior[k],prior[k-out_n])); break; |
2140 | CASE(F_avg_first) cur[k] = raw[k] + (cur[k-out_n] >> 1); break; |
2141 | CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],0,0)); break; |
2142 | } |
2143 | #undef CASE |
2144 | } |
2145 | } |
2146 | return 1; |
2147 | } |
2148 | |
2149 | static int compute_transparency(png *z, uint8 tc[3], int out_n) |
2150 | { |
2151 | stbi *s = &z->s; |
2152 | uint32 i, pixel_count = s->img_x * s->img_y; |
2153 | uint8 *p = z->out; |
2154 | |
2155 | // compute color-based transparency, assuming we've |
2156 | // already got 255 as the alpha value in the output |
2157 | assert(out_n == 2 || out_n == 4); |
2158 | |
2159 | if (out_n == 2) { |
2160 | for (i=0; i < pixel_count; ++i) { |
2161 | p[1] = (p[0] == tc[0] ? 0 : 255); |
2162 | p += 2; |
2163 | } |
2164 | } else { |
2165 | for (i=0; i < pixel_count; ++i) { |
2166 | if (p[0] == tc[0] && p[1] == tc[1] && p[2] == tc[2]) |
2167 | p[3] = 0; |
2168 | p += 4; |
2169 | } |
2170 | } |
2171 | return 1; |
2172 | } |
2173 | |
2174 | static int expand_palette(png *a, uint8 *palette, int len, int pal_img_n) |
2175 | { |
2176 | uint32 i, pixel_count = a->s.img_x * a->s.img_y; |
2177 | uint8 *p, *temp_out, *orig = a->out; |
2178 | |
2179 | p = (uint8 *) malloc(pixel_count * pal_img_n); |
2180 | if (p == NULL) return e("outofmem" , "Out of memory" ); |
2181 | |
2182 | // between here and free(out) below, exitting would leak |
2183 | temp_out = p; |
2184 | |
2185 | if (pal_img_n == 3) { |
2186 | for (i=0; i < pixel_count; ++i) { |
2187 | int n = orig[i]*4; |
2188 | p[0] = palette[n ]; |
2189 | p[1] = palette[n+1]; |
2190 | p[2] = palette[n+2]; |
2191 | p += 3; |
2192 | } |
2193 | } else { |
2194 | for (i=0; i < pixel_count; ++i) { |
2195 | int n = orig[i]*4; |
2196 | p[0] = palette[n ]; |
2197 | p[1] = palette[n+1]; |
2198 | p[2] = palette[n+2]; |
2199 | p[3] = palette[n+3]; |
2200 | p += 4; |
2201 | } |
2202 | } |
2203 | free(a->out); |
2204 | a->out = temp_out; |
2205 | return 1; |
2206 | } |
2207 | |
2208 | static int parse_png_file(png *z, int scan, int req_comp) |
2209 | { |
2210 | uint8 palette[1024], pal_img_n=0; |
2211 | uint8 has_trans=0, tc[3]; |
2212 | uint32 ioff=0, idata_limit=0, i, pal_len=0; |
2213 | int first=1,k; |
2214 | stbi *s = &z->s; |
2215 | |
2216 | if (!check_png_header(s)) return 0; |
2217 | |
2218 | if (scan == SCAN_type) return 1; |
2219 | |
2220 | for(;;first=0) { |
2221 | chunk c = get_chunk_header(s); |
2222 | if (first && c.type != PNG_TYPE('I','H','D','R')) |
2223 | return e("first not IHDR" ,"Corrupt PNG" ); |
2224 | switch (c.type) { |
2225 | case PNG_TYPE('I','H','D','R'): { |
2226 | int depth,color,interlace,comp,filter; |
2227 | if (!first) return e("multiple IHDR" ,"Corrupt PNG" ); |
2228 | if (c.length != 13) return e("bad IHDR len" ,"Corrupt PNG" ); |
2229 | s->img_x = get32(s); if (s->img_x > (1 << 24)) return e("too large" ,"Very large image (corrupt?)" ); |
2230 | s->img_y = get32(s); if (s->img_y > (1 << 24)) return e("too large" ,"Very large image (corrupt?)" ); |
2231 | depth = get8(s); if (depth != 8) return e("8bit only" ,"PNG not supported: 8-bit only" ); |
2232 | color = get8(s); if (color > 6) return e("bad ctype" ,"Corrupt PNG" ); |
2233 | if (color == 3) pal_img_n = 3; else if (color & 1) return e("bad ctype" ,"Corrupt PNG" ); |
2234 | comp = get8(s); if (comp) return e("bad comp method" ,"Corrupt PNG" ); |
2235 | filter= get8(s); if (filter) return e("bad filter method" ,"Corrupt PNG" ); |
2236 | interlace = get8(s); if (interlace) return e("interlaced" ,"PNG not supported: interlaced mode" ); |
2237 | if (!s->img_x || !s->img_y) return e("0-pixel image" ,"Corrupt PNG" ); |
2238 | if (!pal_img_n) { |
2239 | s->img_n = (color & 2 ? 3 : 1) + (color & 4 ? 1 : 0); |
2240 | if ((1 << 30) / s->img_x / s->img_n < s->img_y) return e("too large" , "Image too large to decode" ); |
2241 | if (scan == SCAN_header) return 1; |
2242 | } else { |
2243 | // if paletted, then pal_n is our final components, and |
2244 | // img_n is # components to decompress/filter. |
2245 | s->img_n = 1; |
2246 | if ((1 << 30) / s->img_x / 4 < s->img_y) return e("too large" ,"Corrupt PNG" ); |
2247 | // if SCAN_header, have to scan to see if we have a tRNS |
2248 | } |
2249 | break; |
2250 | } |
2251 | |
2252 | case PNG_TYPE('P','L','T','E'): { |
2253 | if (c.length > 256*3) return e("invalid PLTE" ,"Corrupt PNG" ); |
2254 | pal_len = c.length / 3; |
2255 | if (pal_len * 3 != c.length) return e("invalid PLTE" ,"Corrupt PNG" ); |
2256 | for (i=0; i < pal_len; ++i) { |
2257 | palette[i*4+0] = get8u(s); |
2258 | palette[i*4+1] = get8u(s); |
2259 | palette[i*4+2] = get8u(s); |
2260 | palette[i*4+3] = 255; |
2261 | } |
2262 | break; |
2263 | } |
2264 | |
2265 | case PNG_TYPE('t','R','N','S'): { |
2266 | if (z->idata) return e("tRNS after IDAT" ,"Corrupt PNG" ); |
2267 | if (pal_img_n) { |
2268 | if (scan == SCAN_header) { s->img_n = 4; return 1; } |
2269 | if (pal_len == 0) return e("tRNS before PLTE" ,"Corrupt PNG" ); |
2270 | if (c.length > pal_len) return e("bad tRNS len" ,"Corrupt PNG" ); |
2271 | pal_img_n = 4; |
2272 | for (i=0; i < c.length; ++i) |
2273 | palette[i*4+3] = get8u(s); |
2274 | } else { |
2275 | if (!(s->img_n & 1)) return e("tRNS with alpha" ,"Corrupt PNG" ); |
2276 | if (c.length != (uint32) s->img_n*2) return e("bad tRNS len" ,"Corrupt PNG" ); |
2277 | has_trans = 1; |
2278 | for (k=0; k < s->img_n; ++k) |
2279 | tc[k] = (uint8) get16(s); // non 8-bit images will be larger |
2280 | } |
2281 | break; |
2282 | } |
2283 | |
2284 | case PNG_TYPE('I','D','A','T'): { |
2285 | if (pal_img_n && !pal_len) return e("no PLTE" ,"Corrupt PNG" ); |
2286 | if (scan == SCAN_header) { s->img_n = pal_img_n; return 1; } |
2287 | if (ioff + c.length > idata_limit) { |
2288 | uint8 *p; |
2289 | if (idata_limit == 0) idata_limit = c.length > 4096 ? c.length : 4096; |
2290 | while (ioff + c.length > idata_limit) |
2291 | idata_limit *= 2; |
2292 | p = (uint8 *) realloc(z->idata, idata_limit); if (p == NULL) return e("outofmem" , "Out of memory" ); |
2293 | z->idata = p; |
2294 | } |
2295 | #ifndef STBI_NO_STDIO |
2296 | if (s->img_file) |
2297 | { |
2298 | if (fread(z->idata+ioff,1,c.length,s->img_file) != c.length) return e("outofdata" ,"Corrupt PNG" ); |
2299 | } |
2300 | else |
2301 | #endif |
2302 | { |
2303 | memcpy(z->idata+ioff, s->img_buffer, c.length); |
2304 | s->img_buffer += c.length; |
2305 | } |
2306 | ioff += c.length; |
2307 | break; |
2308 | } |
2309 | |
2310 | case PNG_TYPE('I','E','N','D'): { |
2311 | uint32 raw_len; |
2312 | if (scan != SCAN_load) return 1; |
2313 | if (z->idata == NULL) return e("no IDAT" ,"Corrupt PNG" ); |
2314 | z->expanded = (uint8 *) stbi_zlib_decode_malloc((char *) z->idata, ioff, (int *) &raw_len); |
2315 | if (z->expanded == NULL) return 0; // zlib should set error |
2316 | free(z->idata); z->idata = NULL; |
2317 | if ((req_comp == s->img_n+1 && req_comp != 3 && !pal_img_n) || has_trans) |
2318 | s->img_out_n = s->img_n+1; |
2319 | else |
2320 | s->img_out_n = s->img_n; |
2321 | if (!create_png_image(z, z->expanded, raw_len, s->img_out_n)) return 0; |
2322 | if (has_trans) |
2323 | if (!compute_transparency(z, tc, s->img_out_n)) return 0; |
2324 | if (pal_img_n) { |
2325 | // pal_img_n == 3 or 4 |
2326 | s->img_n = pal_img_n; // record the actual colors we had |
2327 | s->img_out_n = pal_img_n; |
2328 | if (req_comp >= 3) s->img_out_n = req_comp; |
2329 | if (!expand_palette(z, palette, pal_len, s->img_out_n)) |
2330 | return 0; |
2331 | } |
2332 | free(z->expanded); z->expanded = NULL; |
2333 | return 1; |
2334 | } |
2335 | |
2336 | default: |
2337 | // if critical, fail |
2338 | if ((c.type & (1 << 29)) == 0) { |
2339 | #ifndef STBI_NO_FAILURE_STRINGS |
2340 | // not threadsafe |
2341 | static char invalid_chunk[] = "XXXX chunk not known" ; |
2342 | invalid_chunk[0] = (uint8) (c.type >> 24); |
2343 | invalid_chunk[1] = (uint8) (c.type >> 16); |
2344 | invalid_chunk[2] = (uint8) (c.type >> 8); |
2345 | invalid_chunk[3] = (uint8) (c.type >> 0); |
2346 | #endif |
2347 | return e(invalid_chunk, "PNG not supported: unknown chunk type" ); |
2348 | } |
2349 | skip(s, c.length); |
2350 | break; |
2351 | } |
2352 | // end of chunk, read and skip CRC |
2353 | get32(s); |
2354 | } |
2355 | } |
2356 | |
2357 | static unsigned char *do_png(png *p, int *x, int *y, int *n, int req_comp) |
2358 | { |
2359 | unsigned char *result=NULL; |
2360 | p->expanded = NULL; |
2361 | p->idata = NULL; |
2362 | p->out = NULL; |
2363 | if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp" , "Internal error" ); |
2364 | if (parse_png_file(p, SCAN_load, req_comp)) { |
2365 | result = p->out; |
2366 | p->out = NULL; |
2367 | if (req_comp && req_comp != p->s.img_out_n) { |
2368 | result = convert_format(result, p->s.img_out_n, req_comp, p->s.img_x, p->s.img_y); |
2369 | p->s.img_out_n = req_comp; |
2370 | if (result == NULL) return result; |
2371 | } |
2372 | *x = p->s.img_x; |
2373 | *y = p->s.img_y; |
2374 | if (n) *n = p->s.img_n; |
2375 | } |
2376 | free(p->out); p->out = NULL; |
2377 | free(p->expanded); p->expanded = NULL; |
2378 | free(p->idata); p->idata = NULL; |
2379 | |
2380 | return result; |
2381 | } |
2382 | |
2383 | #ifndef STBI_NO_STDIO |
2384 | unsigned char *stbi_png_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) |
2385 | { |
2386 | png p; |
2387 | start_file(&p.s, f); |
2388 | return do_png(&p, x,y,comp,req_comp); |
2389 | } |
2390 | |
2391 | unsigned char *stbi_png_load(char const *filename, int *x, int *y, int *comp, int req_comp) |
2392 | { |
2393 | unsigned char *data; |
2394 | FILE *f = fopen(filename, "rb" ); |
2395 | if (!f) return NULL; |
2396 | data = stbi_png_load_from_file(f,x,y,comp,req_comp); |
2397 | fclose(f); |
2398 | return data; |
2399 | } |
2400 | #endif |
2401 | |
2402 | unsigned char *stbi_png_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) |
2403 | { |
2404 | png p; |
2405 | start_mem(&p.s, buffer,len); |
2406 | return do_png(&p, x,y,comp,req_comp); |
2407 | } |
2408 | |
2409 | #ifndef STBI_NO_STDIO |
2410 | int stbi_png_test_file(FILE *f) |
2411 | { |
2412 | png p; |
2413 | int n,r; |
2414 | n = ftell(f); |
2415 | start_file(&p.s, f); |
2416 | r = parse_png_file(&p, SCAN_type,STBI_default); |
2417 | fseek(f,n,SEEK_SET); |
2418 | return r; |
2419 | } |
2420 | #endif |
2421 | |
2422 | int stbi_png_test_memory(stbi_uc const *buffer, int len) |
2423 | { |
2424 | png p; |
2425 | start_mem(&p.s, buffer, len); |
2426 | return parse_png_file(&p, SCAN_type,STBI_default); |
2427 | } |
2428 | |
2429 | // TODO: load header from png |
2430 | #ifndef STBI_NO_STDIO |
2431 | extern int stbi_png_info (char const *filename, int *x, int *y, int *comp); |
2432 | extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp); |
2433 | #endif |
2434 | extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); |
2435 | |
2436 | // Microsoft/Windows BMP image |
2437 | |
2438 | static int bmp_test(stbi *s) |
2439 | { |
2440 | int sz; |
2441 | if (get8(s) != 'B') return 0; |
2442 | if (get8(s) != 'M') return 0; |
2443 | get32le(s); // discard filesize |
2444 | get16le(s); // discard reserved |
2445 | get16le(s); // discard reserved |
2446 | get32le(s); // discard data offset |
2447 | sz = get32le(s); |
2448 | if (sz == 12 || sz == 40 || sz == 56 || sz == 108) return 1; |
2449 | return 0; |
2450 | } |
2451 | |
2452 | #ifndef STBI_NO_STDIO |
2453 | int stbi_bmp_test_file (FILE *f) |
2454 | { |
2455 | stbi s; |
2456 | int r,n = ftell(f); |
2457 | start_file(&s,f); |
2458 | r = bmp_test(&s); |
2459 | fseek(f,n,SEEK_SET); |
2460 | return r; |
2461 | } |
2462 | #endif |
2463 | |
2464 | int stbi_bmp_test_memory (stbi_uc const *buffer, int len) |
2465 | { |
2466 | stbi s; |
2467 | start_mem(&s, buffer, len); |
2468 | return bmp_test(&s); |
2469 | } |
2470 | |
2471 | // returns 0..31 for the highest set bit |
2472 | static int high_bit(unsigned int z) |
2473 | { |
2474 | int n=0; |
2475 | if (z == 0) return -1; |
2476 | if (z >= 0x10000) n += 16, z >>= 16; |
2477 | if (z >= 0x00100) n += 8, z >>= 8; |
2478 | if (z >= 0x00010) n += 4, z >>= 4; |
2479 | if (z >= 0x00004) n += 2, z >>= 2; |
2480 | if (z >= 0x00002) n += 1, z >>= 1; |
2481 | return n; |
2482 | } |
2483 | |
2484 | static int bitcount(unsigned int a) |
2485 | { |
2486 | a = (a & 0x55555555) + ((a >> 1) & 0x55555555); // max 2 |
2487 | a = (a & 0x33333333) + ((a >> 2) & 0x33333333); // max 4 |
2488 | a = (a + (a >> 4)) & 0x0f0f0f0f; // max 8 per 4, now 8 bits |
2489 | a = (a + (a >> 8)); // max 16 per 8 bits |
2490 | a = (a + (a >> 16)); // max 32 per 8 bits |
2491 | return a & 0xff; |
2492 | } |
2493 | |
2494 | static int shiftsigned(int v, int shift, int bits) |
2495 | { |
2496 | int result; |
2497 | int z=0; |
2498 | |
2499 | if (shift < 0) v <<= -shift; |
2500 | else v >>= shift; |
2501 | result = v; |
2502 | |
2503 | z = bits; |
2504 | while (z < 8) { |
2505 | result += v >> z; |
2506 | z += bits; |
2507 | } |
2508 | return result; |
2509 | } |
2510 | |
2511 | static stbi_uc *bmp_load(stbi *s, int *x, int *y, int *comp, int req_comp) |
2512 | { |
2513 | uint8 *out; |
2514 | unsigned int mr=0,mg=0,mb=0,ma=0; |
2515 | stbi_uc pal[256][4]; |
2516 | int psize=0,i,j,compress=0,width; |
2517 | int bpp, flip_vertically, pad, target, offset, hsz; |
2518 | if (get8(s) != 'B' || get8(s) != 'M') return epuc("not BMP" , "Corrupt BMP" ); |
2519 | get32le(s); // discard filesize |
2520 | get16le(s); // discard reserved |
2521 | get16le(s); // discard reserved |
2522 | offset = get32le(s); |
2523 | hsz = get32le(s); |
2524 | if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108) return epuc("unknown BMP" , "BMP type not supported: unknown" ); |
2525 | failure_reason = "bad BMP" ; |
2526 | if (hsz == 12) { |
2527 | s->img_x = get16le(s); |
2528 | s->img_y = get16le(s); |
2529 | } else { |
2530 | s->img_x = get32le(s); |
2531 | s->img_y = get32le(s); |
2532 | } |
2533 | if (get16le(s) != 1) return 0; |
2534 | bpp = get16le(s); |
2535 | if (bpp == 1) return epuc("monochrome" , "BMP type not supported: 1-bit" ); |
2536 | flip_vertically = ((int) s->img_y) > 0; |
2537 | s->img_y = abs((int) s->img_y); |
2538 | if (hsz == 12) { |
2539 | if (bpp < 24) |
2540 | psize = (offset - 14 - 24) / 3; |
2541 | } else { |
2542 | compress = get32le(s); |
2543 | if (compress == 1 || compress == 2) return epuc("BMP RLE" , "BMP type not supported: RLE" ); |
2544 | get32le(s); // discard sizeof |
2545 | get32le(s); // discard hres |
2546 | get32le(s); // discard vres |
2547 | get32le(s); // discard colorsused |
2548 | get32le(s); // discard max important |
2549 | if (hsz == 40 || hsz == 56) { |
2550 | if (hsz == 56) { |
2551 | get32le(s); |
2552 | get32le(s); |
2553 | get32le(s); |
2554 | get32le(s); |
2555 | } |
2556 | if (bpp == 16 || bpp == 32) { |
2557 | mr = mg = mb = 0; |
2558 | if (compress == 0) { |
2559 | if (bpp == 32) { |
2560 | mr = 0xff << 16; |
2561 | mg = 0xff << 8; |
2562 | mb = 0xff << 0; |
2563 | } else { |
2564 | mr = 31 << 10; |
2565 | mg = 31 << 5; |
2566 | mb = 31 << 0; |
2567 | } |
2568 | } else if (compress == 3) { |
2569 | mr = get32le(s); |
2570 | mg = get32le(s); |
2571 | mb = get32le(s); |
2572 | // not documented, but generated by photoshop and handled by mspaint |
2573 | if (mr == mg && mg == mb) { |
2574 | // ?!?!? |
2575 | return NULL; |
2576 | } |
2577 | } else |
2578 | return NULL; |
2579 | } |
2580 | } else { |
2581 | assert(hsz == 108); |
2582 | mr = get32le(s); |
2583 | mg = get32le(s); |
2584 | mb = get32le(s); |
2585 | ma = get32le(s); |
2586 | get32le(s); // discard color space |
2587 | for (i=0; i < 12; ++i) |
2588 | get32le(s); // discard color space parameters |
2589 | } |
2590 | if (bpp < 16) |
2591 | psize = (offset - 14 - hsz) >> 2; |
2592 | } |
2593 | s->img_n = ma ? 4 : 3; |
2594 | if (req_comp && req_comp >= 3) // we can directly decode 3 or 4 |
2595 | target = req_comp; |
2596 | else |
2597 | target = s->img_n; // if they want monochrome, we'll post-convert |
2598 | out = (stbi_uc *) malloc(target * s->img_x * s->img_y); |
2599 | if (!out) return epuc("outofmem" , "Out of memory" ); |
2600 | if (bpp < 16) { |
2601 | int z=0; |
2602 | if (psize == 0 || psize > 256) { free(out); return epuc("invalid" , "Corrupt BMP" ); } |
2603 | for (i=0; i < psize; ++i) { |
2604 | pal[i][2] = get8(s); |
2605 | pal[i][1] = get8(s); |
2606 | pal[i][0] = get8(s); |
2607 | if (hsz != 12) get8(s); |
2608 | pal[i][3] = 255; |
2609 | } |
2610 | skip(s, offset - 14 - hsz - psize * (hsz == 12 ? 3 : 4)); |
2611 | if (bpp == 4) width = (s->img_x + 1) >> 1; |
2612 | else if (bpp == 8) width = s->img_x; |
2613 | else { free(out); return epuc("bad bpp" , "Corrupt BMP" ); } |
2614 | pad = (-width)&3; |
2615 | for (j=0; j < (int) s->img_y; ++j) { |
2616 | for (i=0; i < (int) s->img_x; i += 2) { |
2617 | int v=get8(s),v2=0; |
2618 | if (bpp == 4) { |
2619 | v2 = v & 15; |
2620 | v >>= 4; |
2621 | } |
2622 | out[z++] = pal[v][0]; |
2623 | out[z++] = pal[v][1]; |
2624 | out[z++] = pal[v][2]; |
2625 | if (target == 4) out[z++] = 255; |
2626 | if (i+1 == (int) s->img_x) break; |
2627 | v = (bpp == 8) ? get8(s) : v2; |
2628 | out[z++] = pal[v][0]; |
2629 | out[z++] = pal[v][1]; |
2630 | out[z++] = pal[v][2]; |
2631 | if (target == 4) out[z++] = 255; |
2632 | } |
2633 | skip(s, pad); |
2634 | } |
2635 | } else { |
2636 | int rshift=0,gshift=0,bshift=0,ashift=0,rcount=0,gcount=0,bcount=0,acount=0; |
2637 | int z = 0; |
2638 | int easy=0; |
2639 | skip(s, offset - 14 - hsz); |
2640 | if (bpp == 24) width = 3 * s->img_x; |
2641 | else if (bpp == 16) width = 2*s->img_x; |
2642 | else /* bpp = 32 and pad = 0 */ width=0; |
2643 | pad = (-width) & 3; |
2644 | if (bpp == 24) { |
2645 | easy = 1; |
2646 | } else if (bpp == 32) { |
2647 | if (mb == 0xff && mg == 0xff00 && mr == 0xff000000 && ma == 0xff000000) |
2648 | easy = 2; |
2649 | } |
2650 | if (!easy) { |
2651 | if (!mr || !mg || !mb) return epuc("bad masks" , "Corrupt BMP" ); |
2652 | // right shift amt to put high bit in position #7 |
2653 | rshift = high_bit(mr)-7; rcount = bitcount(mr); |
2654 | gshift = high_bit(mg)-7; gcount = bitcount(mr); |
2655 | bshift = high_bit(mb)-7; bcount = bitcount(mr); |
2656 | ashift = high_bit(ma)-7; acount = bitcount(mr); |
2657 | } |
2658 | for (j=0; j < (int) s->img_y; ++j) { |
2659 | if (easy) { |
2660 | for (i=0; i < (int) s->img_x; ++i) { |
2661 | int a; |
2662 | out[z+2] = get8(s); |
2663 | out[z+1] = get8(s); |
2664 | out[z+0] = get8(s); |
2665 | z += 3; |
2666 | a = (easy == 2 ? get8(s) : 255); |
2667 | if (target == 4) out[z++] = a; |
2668 | } |
2669 | } else { |
2670 | for (i=0; i < (int) s->img_x; ++i) { |
2671 | uint32 v = (bpp == 16 ? get16le(s) : get32le(s)); |
2672 | int a; |
2673 | out[z++] = shiftsigned(v & mr, rshift, rcount); |
2674 | out[z++] = shiftsigned(v & mg, gshift, gcount); |
2675 | out[z++] = shiftsigned(v & mb, bshift, bcount); |
2676 | a = (ma ? shiftsigned(v & ma, ashift, acount) : 255); |
2677 | if (target == 4) out[z++] = a; |
2678 | } |
2679 | } |
2680 | skip(s, pad); |
2681 | } |
2682 | } |
2683 | if (flip_vertically) { |
2684 | stbi_uc t; |
2685 | for (j=0; j < (int) s->img_y>>1; ++j) { |
2686 | stbi_uc *p1 = out + j *s->img_x*target; |
2687 | stbi_uc *p2 = out + (s->img_y-1-j)*s->img_x*target; |
2688 | for (i=0; i < (int) s->img_x*target; ++i) { |
2689 | t = p1[i], p1[i] = p2[i], p2[i] = t; |
2690 | } |
2691 | } |
2692 | } |
2693 | |
2694 | if (req_comp && req_comp != target) { |
2695 | out = convert_format(out, target, req_comp, s->img_x, s->img_y); |
2696 | if (out == NULL) return out; // convert_format frees input on failure |
2697 | } |
2698 | |
2699 | *x = s->img_x; |
2700 | *y = s->img_y; |
2701 | if (comp) *comp = target; |
2702 | return out; |
2703 | } |
2704 | |
2705 | #ifndef STBI_NO_STDIO |
2706 | stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp) |
2707 | { |
2708 | stbi_uc *data; |
2709 | FILE *f = fopen(filename, "rb" ); |
2710 | if (!f) return NULL; |
2711 | data = stbi_bmp_load_from_file(f, x,y,comp,req_comp); |
2712 | fclose(f); |
2713 | return data; |
2714 | } |
2715 | |
2716 | stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp) |
2717 | { |
2718 | stbi s; |
2719 | start_file(&s, f); |
2720 | return bmp_load(&s, x,y,comp,req_comp); |
2721 | } |
2722 | #endif |
2723 | |
2724 | stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) |
2725 | { |
2726 | stbi s; |
2727 | start_mem(&s, buffer, len); |
2728 | return bmp_load(&s, x,y,comp,req_comp); |
2729 | } |
2730 | |
2731 | // Targa Truevision - TGA |
2732 | // by Jonathan Dummer |
2733 | |
2734 | static int tga_test(stbi *s) |
2735 | { |
2736 | int sz; |
2737 | get8u(s); // discard Offset |
2738 | sz = get8u(s); // color type |
2739 | if( sz > 1 ) return 0; // only RGB or indexed allowed |
2740 | sz = get8u(s); // image type |
2741 | if( (sz != 1) && (sz != 2) && (sz != 3) && (sz != 9) && (sz != 10) && (sz != 11) ) return 0; // only RGB or grey allowed, +/- RLE |
2742 | get16(s); // discard palette start |
2743 | get16(s); // discard palette length |
2744 | get8(s); // discard bits per palette color entry |
2745 | get16(s); // discard x origin |
2746 | get16(s); // discard y origin |
2747 | if( get16(s) < 1 ) return 0; // test width |
2748 | if( get16(s) < 1 ) return 0; // test height |
2749 | sz = get8(s); // bits per pixel |
2750 | if( (sz != 8) && (sz != 16) && (sz != 24) && (sz != 32) ) return 0; // only RGB or RGBA or grey allowed |
2751 | return 1; // seems to have passed everything |
2752 | } |
2753 | |
2754 | #ifndef STBI_NO_STDIO |
2755 | int stbi_tga_test_file (FILE *f) |
2756 | { |
2757 | stbi s; |
2758 | int r,n = ftell(f); |
2759 | start_file(&s, f); |
2760 | r = tga_test(&s); |
2761 | fseek(f,n,SEEK_SET); |
2762 | return r; |
2763 | } |
2764 | #endif |
2765 | |
2766 | int stbi_tga_test_memory (stbi_uc const *buffer, int len) |
2767 | { |
2768 | stbi s; |
2769 | start_mem(&s, buffer, len); |
2770 | return tga_test(&s); |
2771 | } |
2772 | |
2773 | static stbi_uc *tga_load(stbi *s, int *x, int *y, int *comp, int req_comp) |
2774 | { |
2775 | // read in the TGA header stuff |
2776 | int tga_offset = get8u(s); |
2777 | int tga_indexed = get8u(s); |
2778 | int tga_image_type = get8u(s); |
2779 | int tga_is_RLE = 0; |
2780 | int tga_palette_start = get16le(s); |
2781 | int tga_palette_len = get16le(s); |
2782 | int tga_palette_bits = get8u(s); |
2783 | int tga_x_origin = get16le(s); |
2784 | int tga_y_origin = get16le(s); |
2785 | int tga_width = get16le(s); |
2786 | int tga_height = get16le(s); |
2787 | int tga_bits_per_pixel = get8u(s); |
2788 | int tga_inverted = get8u(s); |
2789 | // image data |
2790 | unsigned char *tga_data; |
2791 | unsigned char *tga_palette = NULL; |
2792 | int i, j; |
2793 | unsigned char raw_data[4]; |
2794 | unsigned char trans_data[] = { 0,0,0,0 }; |
2795 | int RLE_count = 0; |
2796 | int RLE_repeating = 0; |
2797 | int read_next_pixel = 1; |
2798 | // do a tiny bit of precessing |
2799 | if( tga_image_type >= 8 ) |
2800 | { |
2801 | tga_image_type -= 8; |
2802 | tga_is_RLE = 1; |
2803 | } |
2804 | /* int tga_alpha_bits = tga_inverted & 15; */ |
2805 | tga_inverted = 1 - ((tga_inverted >> 5) & 1); |
2806 | |
2807 | // error check |
2808 | if( //(tga_indexed) || |
2809 | (tga_width < 1) || (tga_height < 1) || |
2810 | (tga_image_type < 1) || (tga_image_type > 3) || |
2811 | ((tga_bits_per_pixel != 8) && (tga_bits_per_pixel != 16) && |
2812 | (tga_bits_per_pixel != 24) && (tga_bits_per_pixel != 32)) |
2813 | ) |
2814 | { |
2815 | return NULL; |
2816 | } |
2817 | |
2818 | // If I'm paletted, then I'll use the number of bits from the palette |
2819 | if( tga_indexed ) |
2820 | { |
2821 | tga_bits_per_pixel = tga_palette_bits; |
2822 | } |
2823 | |
2824 | // tga info |
2825 | *x = tga_width; |
2826 | *y = tga_height; |
2827 | if( (req_comp < 1) || (req_comp > 4) ) |
2828 | { |
2829 | // just use whatever the file was |
2830 | req_comp = tga_bits_per_pixel / 8; |
2831 | *comp = req_comp; |
2832 | } else |
2833 | { |
2834 | // force a new number of components |
2835 | *comp = tga_bits_per_pixel/8; |
2836 | } |
2837 | tga_data = (unsigned char*)malloc( tga_width * tga_height * req_comp ); |
2838 | |
2839 | // skip to the data's starting position (offset usually = 0) |
2840 | skip(s, tga_offset ); |
2841 | // do I need to load a palette? |
2842 | if( tga_indexed ) |
2843 | { |
2844 | // any data to skip? (offset usually = 0) |
2845 | skip(s, tga_palette_start ); |
2846 | // load the palette |
2847 | tga_palette = (unsigned char*)malloc( tga_palette_len * tga_palette_bits / 8 ); |
2848 | getn(s, tga_palette, tga_palette_len * tga_palette_bits / 8 ); |
2849 | } |
2850 | // load the data |
2851 | for( i = 0; i < tga_width * tga_height; ++i ) |
2852 | { |
2853 | // if I'm in RLE mode, do I need to get a RLE chunk? |
2854 | if( tga_is_RLE ) |
2855 | { |
2856 | if( RLE_count == 0 ) |
2857 | { |
2858 | // yep, get the next byte as a RLE command |
2859 | int RLE_cmd = get8u(s); |
2860 | RLE_count = 1 + (RLE_cmd & 127); |
2861 | RLE_repeating = RLE_cmd >> 7; |
2862 | read_next_pixel = 1; |
2863 | } else if( !RLE_repeating ) |
2864 | { |
2865 | read_next_pixel = 1; |
2866 | } |
2867 | } else |
2868 | { |
2869 | read_next_pixel = 1; |
2870 | } |
2871 | // OK, if I need to read a pixel, do it now |
2872 | if( read_next_pixel ) |
2873 | { |
2874 | // load however much data we did have |
2875 | if( tga_indexed ) |
2876 | { |
2877 | // read in 1 byte, then perform the lookup |
2878 | int pal_idx = get8u(s); |
2879 | if( pal_idx >= tga_palette_len ) |
2880 | { |
2881 | // invalid index |
2882 | pal_idx = 0; |
2883 | } |
2884 | pal_idx *= tga_bits_per_pixel / 8; |
2885 | for( j = 0; j*8 < tga_bits_per_pixel; ++j ) |
2886 | { |
2887 | raw_data[j] = tga_palette[pal_idx+j]; |
2888 | } |
2889 | } else |
2890 | { |
2891 | // read in the data raw |
2892 | for( j = 0; j*8 < tga_bits_per_pixel; ++j ) |
2893 | { |
2894 | raw_data[j] = get8u(s); |
2895 | } |
2896 | } |
2897 | // convert raw to the intermediate format |
2898 | switch( tga_bits_per_pixel ) |
2899 | { |
2900 | case 8: |
2901 | // Luminous => RGBA |
2902 | trans_data[0] = raw_data[0]; |
2903 | trans_data[1] = raw_data[0]; |
2904 | trans_data[2] = raw_data[0]; |
2905 | trans_data[3] = 255; |
2906 | break; |
2907 | case 16: |
2908 | // Luminous,Alpha => RGBA |
2909 | trans_data[0] = raw_data[0]; |
2910 | trans_data[1] = raw_data[0]; |
2911 | trans_data[2] = raw_data[0]; |
2912 | trans_data[3] = raw_data[1]; |
2913 | break; |
2914 | case 24: |
2915 | // BGR => RGBA |
2916 | trans_data[0] = raw_data[2]; |
2917 | trans_data[1] = raw_data[1]; |
2918 | trans_data[2] = raw_data[0]; |
2919 | trans_data[3] = 255; |
2920 | break; |
2921 | case 32: |
2922 | // BGRA => RGBA |
2923 | trans_data[0] = raw_data[2]; |
2924 | trans_data[1] = raw_data[1]; |
2925 | trans_data[2] = raw_data[0]; |
2926 | trans_data[3] = raw_data[3]; |
2927 | break; |
2928 | } |
2929 | // clear the reading flag for the next pixel |
2930 | read_next_pixel = 0; |
2931 | } // end of reading a pixel |
2932 | // convert to final format |
2933 | switch( req_comp ) |
2934 | { |
2935 | case 1: |
2936 | // RGBA => Luminance |
2937 | tga_data[i*req_comp+0] = compute_y(trans_data[0],trans_data[1],trans_data[2]); |
2938 | break; |
2939 | case 2: |
2940 | // RGBA => Luminance,Alpha |
2941 | tga_data[i*req_comp+0] = compute_y(trans_data[0],trans_data[1],trans_data[2]); |
2942 | tga_data[i*req_comp+1] = trans_data[3]; |
2943 | break; |
2944 | case 3: |
2945 | // RGBA => RGB |
2946 | tga_data[i*req_comp+0] = trans_data[0]; |
2947 | tga_data[i*req_comp+1] = trans_data[1]; |
2948 | tga_data[i*req_comp+2] = trans_data[2]; |
2949 | break; |
2950 | case 4: |
2951 | // RGBA => RGBA |
2952 | tga_data[i*req_comp+0] = trans_data[0]; |
2953 | tga_data[i*req_comp+1] = trans_data[1]; |
2954 | tga_data[i*req_comp+2] = trans_data[2]; |
2955 | tga_data[i*req_comp+3] = trans_data[3]; |
2956 | break; |
2957 | } |
2958 | // in case we're in RLE mode, keep counting down |
2959 | --RLE_count; |
2960 | } |
2961 | // do I need to invert the image? |
2962 | if( tga_inverted ) |
2963 | { |
2964 | for( j = 0; j*2 < tga_height; ++j ) |
2965 | { |
2966 | int index1 = j * tga_width * req_comp; |
2967 | int index2 = (tga_height - 1 - j) * tga_width * req_comp; |
2968 | for( i = tga_width * req_comp; i > 0; --i ) |
2969 | { |
2970 | unsigned char temp = tga_data[index1]; |
2971 | tga_data[index1] = tga_data[index2]; |
2972 | tga_data[index2] = temp; |
2973 | ++index1; |
2974 | ++index2; |
2975 | } |
2976 | } |
2977 | } |
2978 | // clear my palette, if I had one |
2979 | if( tga_palette != NULL ) |
2980 | { |
2981 | free( tga_palette ); |
2982 | } |
2983 | // the things I do to get rid of an error message, and yet keep |
2984 | // Microsoft's C compilers happy... [8^( |
2985 | tga_palette_start = tga_palette_len = tga_palette_bits = |
2986 | tga_x_origin = tga_y_origin = 0; |
2987 | // OK, done |
2988 | return tga_data; |
2989 | } |
2990 | |
2991 | #ifndef STBI_NO_STDIO |
2992 | stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp) |
2993 | { |
2994 | stbi_uc *data; |
2995 | FILE *f = fopen(filename, "rb" ); |
2996 | if (!f) return NULL; |
2997 | data = stbi_tga_load_from_file(f, x,y,comp,req_comp); |
2998 | fclose(f); |
2999 | return data; |
3000 | } |
3001 | |
3002 | stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp) |
3003 | { |
3004 | stbi s; |
3005 | start_file(&s, f); |
3006 | return tga_load(&s, x,y,comp,req_comp); |
3007 | } |
3008 | #endif |
3009 | |
3010 | stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) |
3011 | { |
3012 | stbi s; |
3013 | start_mem(&s, buffer, len); |
3014 | return tga_load(&s, x,y,comp,req_comp); |
3015 | } |
3016 | |
3017 | |
3018 | // ************************************************************************************************* |
3019 | // Photoshop PSD loader -- PD by Thatcher Ulrich, integration by Nicholas Schulz, tweaked by STB |
3020 | |
3021 | static int psd_test(stbi *s) |
3022 | { |
3023 | if (get32(s) != 0x38425053) return 0; // "8BPS" |
3024 | else return 1; |
3025 | } |
3026 | |
3027 | #ifndef STBI_NO_STDIO |
3028 | int stbi_psd_test_file(FILE *f) |
3029 | { |
3030 | stbi s; |
3031 | int r,n = ftell(f); |
3032 | start_file(&s, f); |
3033 | r = psd_test(&s); |
3034 | fseek(f,n,SEEK_SET); |
3035 | return r; |
3036 | } |
3037 | #endif |
3038 | |
3039 | int stbi_psd_test_memory(stbi_uc const *buffer, int len) |
3040 | { |
3041 | stbi s; |
3042 | start_mem(&s, buffer, len); |
3043 | return psd_test(&s); |
3044 | } |
3045 | |
3046 | static stbi_uc *psd_load(stbi *s, int *x, int *y, int *comp, int req_comp) |
3047 | { |
3048 | int pixelCount; |
3049 | int channelCount, compression; |
3050 | int channel, i, count, len; |
3051 | int w,h; |
3052 | uint8 *out; |
3053 | |
3054 | // Check identifier |
3055 | if (get32(s) != 0x38425053) // "8BPS" |
3056 | return epuc("not PSD" , "Corrupt PSD image" ); |
3057 | |
3058 | // Check file type version. |
3059 | if (get16(s) != 1) |
3060 | return epuc("wrong version" , "Unsupported version of PSD image" ); |
3061 | |
3062 | // Skip 6 reserved bytes. |
3063 | skip(s, 6 ); |
3064 | |
3065 | // Read the number of channels (R, G, B, A, etc). |
3066 | channelCount = get16(s); |
3067 | if (channelCount < 0 || channelCount > 16) |
3068 | return epuc("wrong channel count" , "Unsupported number of channels in PSD image" ); |
3069 | |
3070 | // Read the rows and columns of the image. |
3071 | h = get32(s); |
3072 | w = get32(s); |
3073 | |
3074 | // Make sure the depth is 8 bits. |
3075 | if (get16(s) != 8) |
3076 | return epuc("unsupported bit depth" , "PSD bit depth is not 8 bit" ); |
3077 | |
3078 | // Make sure the color mode is RGB. |
3079 | // Valid options are: |
3080 | // 0: Bitmap |
3081 | // 1: Grayscale |
3082 | // 2: Indexed color |
3083 | // 3: RGB color |
3084 | // 4: CMYK color |
3085 | // 7: Multichannel |
3086 | // 8: Duotone |
3087 | // 9: Lab color |
3088 | if (get16(s) != 3) |
3089 | return epuc("wrong color format" , "PSD is not in RGB color format" ); |
3090 | |
3091 | // Skip the Mode Data. (It's the palette for indexed color; other info for other modes.) |
3092 | skip(s,get32(s) ); |
3093 | |
3094 | // Skip the image resources. (resolution, pen tool paths, etc) |
3095 | skip(s, get32(s) ); |
3096 | |
3097 | // Skip the reserved data. |
3098 | skip(s, get32(s) ); |
3099 | |
3100 | // Find out if the data is compressed. |
3101 | // Known values: |
3102 | // 0: no compression |
3103 | // 1: RLE compressed |
3104 | compression = get16(s); |
3105 | if (compression > 1) |
3106 | return epuc("bad compression" , "PSD has an unknown compression format" ); |
3107 | |
3108 | // Create the destination image. |
3109 | out = (stbi_uc *) malloc(4 * w*h); |
3110 | if (!out) return epuc("outofmem" , "Out of memory" ); |
3111 | pixelCount = w*h; |
3112 | |
3113 | // Initialize the data to zero. |
3114 | //memset( out, 0, pixelCount * 4 ); |
3115 | |
3116 | // Finally, the image data. |
3117 | if (compression) { |
3118 | // RLE as used by .PSD and .TIFF |
3119 | // Loop until you get the number of unpacked bytes you are expecting: |
3120 | // Read the next source byte into n. |
3121 | // If n is between 0 and 127 inclusive, copy the next n+1 bytes literally. |
3122 | // Else if n is between -127 and -1 inclusive, copy the next byte -n+1 times. |
3123 | // Else if n is 128, noop. |
3124 | // Endloop |
3125 | |
3126 | // The RLE-compressed data is preceeded by a 2-byte data count for each row in the data, |
3127 | // which we're going to just skip. |
3128 | skip(s, h * channelCount * 2 ); |
3129 | |
3130 | // Read the RLE data by channel. |
3131 | for (channel = 0; channel < 4; channel++) { |
3132 | uint8 *p; |
3133 | |
3134 | p = out+channel; |
3135 | if (channel >= channelCount) { |
3136 | // Fill this channel with default data. |
3137 | for (i = 0; i < pixelCount; i++) *p = (channel == 3 ? 255 : 0), p += 4; |
3138 | } else { |
3139 | // Read the RLE data. |
3140 | count = 0; |
3141 | while (count < pixelCount) { |
3142 | len = get8(s); |
3143 | if (len == 128) { |
3144 | // No-op. |
3145 | } else if (len < 128) { |
3146 | // Copy next len+1 bytes literally. |
3147 | len++; |
3148 | count += len; |
3149 | while (len) { |
3150 | *p = get8(s); |
3151 | p += 4; |
3152 | len--; |
3153 | } |
3154 | } else if (len > 128) { |
3155 | uint32 val; |
3156 | // Next -len+1 bytes in the dest are replicated from next source byte. |
3157 | // (Interpret len as a negative 8-bit int.) |
3158 | len ^= 0x0FF; |
3159 | len += 2; |
3160 | val = get8(s); |
3161 | count += len; |
3162 | while (len) { |
3163 | *p = val; |
3164 | p += 4; |
3165 | len--; |
3166 | } |
3167 | } |
3168 | } |
3169 | } |
3170 | } |
3171 | |
3172 | } else { |
3173 | // We're at the raw image data. It's each channel in order (Red, Green, Blue, Alpha, ...) |
3174 | // where each channel consists of an 8-bit value for each pixel in the image. |
3175 | |
3176 | // Read the data by channel. |
3177 | for (channel = 0; channel < 4; channel++) { |
3178 | uint8 *p; |
3179 | |
3180 | p = out + channel; |
3181 | if (channel > channelCount) { |
3182 | // Fill this channel with default data. |
3183 | for (i = 0; i < pixelCount; i++) *p = channel == 3 ? 255 : 0, p += 4; |
3184 | } else { |
3185 | // Read the data. |
3186 | count = 0; |
3187 | for (i = 0; i < pixelCount; i++) |
3188 | *p = get8(s), p += 4; |
3189 | } |
3190 | } |
3191 | } |
3192 | |
3193 | if (req_comp && req_comp != 4) { |
3194 | out = convert_format(out, 4, req_comp, w, h); |
3195 | if (out == NULL) return out; // convert_format frees input on failure |
3196 | } |
3197 | |
3198 | if (comp) *comp = channelCount; |
3199 | *y = h; |
3200 | *x = w; |
3201 | |
3202 | return out; |
3203 | } |
3204 | |
3205 | #ifndef STBI_NO_STDIO |
3206 | stbi_uc *stbi_psd_load(char const *filename, int *x, int *y, int *comp, int req_comp) |
3207 | { |
3208 | stbi_uc *data; |
3209 | FILE *f = fopen(filename, "rb" ); |
3210 | if (!f) return NULL; |
3211 | data = stbi_psd_load_from_file(f, x,y,comp,req_comp); |
3212 | fclose(f); |
3213 | return data; |
3214 | } |
3215 | |
3216 | stbi_uc *stbi_psd_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) |
3217 | { |
3218 | stbi s; |
3219 | start_file(&s, f); |
3220 | return psd_load(&s, x,y,comp,req_comp); |
3221 | } |
3222 | #endif |
3223 | |
3224 | stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) |
3225 | { |
3226 | stbi s; |
3227 | start_mem(&s, buffer, len); |
3228 | return psd_load(&s, x,y,comp,req_comp); |
3229 | } |
3230 | |
3231 | |
3232 | // ************************************************************************************************* |
3233 | // Radiance RGBE HDR loader |
3234 | // originally by Nicolas Schulz |
3235 | #ifndef STBI_NO_HDR |
3236 | static int hdr_test(stbi *s) |
3237 | { |
3238 | char *signature = "#?RADIANCE\n" ; |
3239 | int i; |
3240 | for (i=0; signature[i]; ++i) |
3241 | if (get8(s) != signature[i]) |
3242 | return 0; |
3243 | return 1; |
3244 | } |
3245 | |
3246 | int stbi_hdr_test_memory(stbi_uc const *buffer, int len) |
3247 | { |
3248 | stbi s; |
3249 | start_mem(&s, buffer, len); |
3250 | return hdr_test(&s); |
3251 | } |
3252 | |
3253 | #ifndef STBI_NO_STDIO |
3254 | int stbi_hdr_test_file(FILE *f) |
3255 | { |
3256 | stbi s; |
3257 | int r,n = ftell(f); |
3258 | start_file(&s, f); |
3259 | r = hdr_test(&s); |
3260 | fseek(f,n,SEEK_SET); |
3261 | return r; |
3262 | } |
3263 | #endif |
3264 | |
3265 | #define HDR_BUFLEN 1024 |
3266 | static char *hdr_gettoken(stbi *z, char *buffer) |
3267 | { |
3268 | int len=0; |
3269 | //char *s = buffer, |
3270 | char c = '\0'; |
3271 | |
3272 | c = get8(z); |
3273 | |
3274 | while (!at_eof(z) && c != '\n') { |
3275 | buffer[len++] = c; |
3276 | if (len == HDR_BUFLEN-1) { |
3277 | // flush to end of line |
3278 | while (!at_eof(z) && get8(z) != '\n') |
3279 | ; |
3280 | break; |
3281 | } |
3282 | c = get8(z); |
3283 | } |
3284 | |
3285 | buffer[len] = 0; |
3286 | return buffer; |
3287 | } |
3288 | |
3289 | static void hdr_convert(float *output, stbi_uc *input, int req_comp) |
3290 | { |
3291 | if( input[3] != 0 ) { |
3292 | float f1; |
3293 | // Exponent |
3294 | f1 = (float) ldexp(1.0f, input[3] - (int)(128 + 8)); |
3295 | if (req_comp <= 2) |
3296 | output[0] = (input[0] + input[1] + input[2]) * f1 / 3; |
3297 | else { |
3298 | output[0] = input[0] * f1; |
3299 | output[1] = input[1] * f1; |
3300 | output[2] = input[2] * f1; |
3301 | } |
3302 | if (req_comp == 2) output[1] = 1; |
3303 | if (req_comp == 4) output[3] = 1; |
3304 | } else { |
3305 | switch (req_comp) { |
3306 | case 4: output[3] = 1; /* fallthrough */ |
3307 | case 3: output[0] = output[1] = output[2] = 0; |
3308 | break; |
3309 | case 2: output[1] = 1; /* fallthrough */ |
3310 | case 1: output[0] = 0; |
3311 | break; |
3312 | } |
3313 | } |
3314 | } |
3315 | |
3316 | |
3317 | static float *hdr_load(stbi *s, int *x, int *y, int *comp, int req_comp) |
3318 | { |
3319 | char buffer[HDR_BUFLEN]; |
3320 | char *token; |
3321 | int valid = 0; |
3322 | int width, height; |
3323 | stbi_uc *scanline; |
3324 | float *hdr_data; |
3325 | int len; |
3326 | unsigned char count, value; |
3327 | int i, j, k, c1,c2, z; |
3328 | |
3329 | |
3330 | // Check identifier |
3331 | if (strcmp(hdr_gettoken(s,buffer), "#?RADIANCE" ) != 0) |
3332 | return epf("not HDR" , "Corrupt HDR image" ); |
3333 | |
3334 | // Parse header |
3335 | while(1) { |
3336 | token = hdr_gettoken(s,buffer); |
3337 | if (token[0] == 0) break; |
3338 | if (strcmp(token, "FORMAT=32-bit_rle_rgbe" ) == 0) valid = 1; |
3339 | } |
3340 | |
3341 | if (!valid) return epf("unsupported format" , "Unsupported HDR format" ); |
3342 | |
3343 | // Parse width and height |
3344 | // can't use sscanf() if we're not using stdio! |
3345 | token = hdr_gettoken(s,buffer); |
3346 | if (strncmp(token, "-Y " , 3)) return epf("unsupported data layout" , "Unsupported HDR format" ); |
3347 | token += 3; |
3348 | height = strtol(token, &token, 10); |
3349 | while (*token == ' ') ++token; |
3350 | if (strncmp(token, "+X " , 3)) return epf("unsupported data layout" , "Unsupported HDR format" ); |
3351 | token += 3; |
3352 | width = strtol(token, NULL, 10); |
3353 | |
3354 | *x = width; |
3355 | *y = height; |
3356 | |
3357 | *comp = 3; |
3358 | if (req_comp == 0) req_comp = 3; |
3359 | |
3360 | // Read data |
3361 | hdr_data = (float *) malloc(height * width * req_comp * sizeof(float)); |
3362 | |
3363 | // Load image data |
3364 | // image data is stored as some number of sca |
3365 | if( width < 8 || width >= 32768) { |
3366 | // Read flat data |
3367 | for (j=0; j < height; ++j) { |
3368 | for (i=0; i < width; ++i) { |
3369 | stbi_uc rgbe[4]; |
3370 | main_decode_loop: |
3371 | getn(s, rgbe, 4); |
3372 | hdr_convert(hdr_data + j * width * req_comp + i * req_comp, rgbe, req_comp); |
3373 | } |
3374 | } |
3375 | } else { |
3376 | // Read RLE-encoded data |
3377 | scanline = NULL; |
3378 | |
3379 | for (j = 0; j < height; ++j) { |
3380 | c1 = get8(s); |
3381 | c2 = get8(s); |
3382 | len = get8(s); |
3383 | if (c1 != 2 || c2 != 2 || (len & 0x80)) { |
3384 | // not run-length encoded, so we have to actually use THIS data as a decoded |
3385 | // pixel (note this can't be a valid pixel--one of RGB must be >= 128) |
3386 | stbi_uc rgbe[4] = { c1,c2,len, get8(s) }; |
3387 | hdr_convert(hdr_data, rgbe, req_comp); |
3388 | i = 1; |
3389 | j = 0; |
3390 | free(scanline); |
3391 | goto main_decode_loop; // yes, this is fucking insane; blame the fucking insane format |
3392 | } |
3393 | len <<= 8; |
3394 | len |= get8(s); |
3395 | if (len != width) { free(hdr_data); free(scanline); return epf("invalid decoded scanline length" , "corrupt HDR" ); } |
3396 | if (scanline == NULL) scanline = (stbi_uc *) malloc(width * 4); |
3397 | |
3398 | for (k = 0; k < 4; ++k) { |
3399 | i = 0; |
3400 | while (i < width) { |
3401 | count = get8(s); |
3402 | if (count > 128) { |
3403 | // Run |
3404 | value = get8(s); |
3405 | count -= 128; |
3406 | for (z = 0; z < count; ++z) |
3407 | scanline[i++ * 4 + k] = value; |
3408 | } else { |
3409 | // Dump |
3410 | for (z = 0; z < count; ++z) |
3411 | scanline[i++ * 4 + k] = get8(s); |
3412 | } |
3413 | } |
3414 | } |
3415 | for (i=0; i < width; ++i) |
3416 | hdr_convert(hdr_data+(j*width + i)*req_comp, scanline + i*4, req_comp); |
3417 | } |
3418 | free(scanline); |
3419 | } |
3420 | |
3421 | return hdr_data; |
3422 | } |
3423 | |
3424 | static stbi_uc *hdr_load_rgbe(stbi *s, int *x, int *y, int *comp, int req_comp) |
3425 | { |
3426 | char buffer[HDR_BUFLEN]; |
3427 | char *token; |
3428 | int valid = 0; |
3429 | int width, height; |
3430 | stbi_uc *scanline; |
3431 | stbi_uc *rgbe_data; |
3432 | int len; |
3433 | unsigned char count, value; |
3434 | int i, j, k, c1,c2, z; |
3435 | |
3436 | |
3437 | // Check identifier |
3438 | if (strcmp(hdr_gettoken(s,buffer), "#?RADIANCE" ) != 0) |
3439 | return epuc("not HDR" , "Corrupt HDR image" ); |
3440 | |
3441 | // Parse header |
3442 | while(1) { |
3443 | token = hdr_gettoken(s,buffer); |
3444 | if (token[0] == 0) break; |
3445 | if (strcmp(token, "FORMAT=32-bit_rle_rgbe" ) == 0) valid = 1; |
3446 | } |
3447 | |
3448 | if (!valid) return epuc("unsupported format" , "Unsupported HDR format" ); |
3449 | |
3450 | // Parse width and height |
3451 | // can't use sscanf() if we're not using stdio! |
3452 | token = hdr_gettoken(s,buffer); |
3453 | if (strncmp(token, "-Y " , 3)) return epuc("unsupported data layout" , "Unsupported HDR format" ); |
3454 | token += 3; |
3455 | height = strtol(token, &token, 10); |
3456 | while (*token == ' ') ++token; |
3457 | if (strncmp(token, "+X " , 3)) return epuc("unsupported data layout" , "Unsupported HDR format" ); |
3458 | token += 3; |
3459 | width = strtol(token, NULL, 10); |
3460 | |
3461 | *x = width; |
3462 | *y = height; |
3463 | |
3464 | // RGBE _MUST_ come out as 4 components |
3465 | *comp = 4; |
3466 | req_comp = 4; |
3467 | |
3468 | // Read data |
3469 | rgbe_data = (stbi_uc *) malloc(height * width * req_comp * sizeof(stbi_uc)); |
3470 | // point to the beginning |
3471 | scanline = rgbe_data; |
3472 | |
3473 | // Load image data |
3474 | // image data is stored as some number of scan lines |
3475 | if( width < 8 || width >= 32768) { |
3476 | // Read flat data |
3477 | for (j=0; j < height; ++j) { |
3478 | for (i=0; i < width; ++i) { |
3479 | main_decode_loop: |
3480 | //getn(rgbe, 4); |
3481 | getn(s,scanline, 4); |
3482 | scanline += 4; |
3483 | } |
3484 | } |
3485 | } else { |
3486 | // Read RLE-encoded data |
3487 | for (j = 0; j < height; ++j) { |
3488 | c1 = get8(s); |
3489 | c2 = get8(s); |
3490 | len = get8(s); |
3491 | if (c1 != 2 || c2 != 2 || (len & 0x80)) { |
3492 | // not run-length encoded, so we have to actually use THIS data as a decoded |
3493 | // pixel (note this can't be a valid pixel--one of RGB must be >= 128) |
3494 | scanline[0] = c1; |
3495 | scanline[1] = c2; |
3496 | scanline[2] = len; |
3497 | scanline[3] = get8(s); |
3498 | scanline += 4; |
3499 | i = 1; |
3500 | j = 0; |
3501 | goto main_decode_loop; // yes, this is insane; blame the insane format |
3502 | } |
3503 | len <<= 8; |
3504 | len |= get8(s); |
3505 | if (len != width) { free(rgbe_data); return epuc("invalid decoded scanline length" , "corrupt HDR" ); } |
3506 | for (k = 0; k < 4; ++k) { |
3507 | i = 0; |
3508 | while (i < width) { |
3509 | count = get8(s); |
3510 | if (count > 128) { |
3511 | // Run |
3512 | value = get8(s); |
3513 | count -= 128; |
3514 | for (z = 0; z < count; ++z) |
3515 | scanline[i++ * 4 + k] = value; |
3516 | } else { |
3517 | // Dump |
3518 | for (z = 0; z < count; ++z) |
3519 | scanline[i++ * 4 + k] = get8(s); |
3520 | } |
3521 | } |
3522 | } |
3523 | // move the scanline on |
3524 | scanline += 4 * width; |
3525 | } |
3526 | } |
3527 | |
3528 | return rgbe_data; |
3529 | } |
3530 | |
3531 | #ifndef STBI_NO_STDIO |
3532 | float *stbi_hdr_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp) |
3533 | { |
3534 | stbi s; |
3535 | start_file(&s,f); |
3536 | return hdr_load(&s,x,y,comp,req_comp); |
3537 | } |
3538 | |
3539 | stbi_uc *stbi_hdr_load_rgbe_file(FILE *f, int *x, int *y, int *comp, int req_comp) |
3540 | { |
3541 | stbi s; |
3542 | start_file(&s,f); |
3543 | return hdr_load_rgbe(&s,x,y,comp,req_comp); |
3544 | } |
3545 | |
3546 | stbi_uc *stbi_hdr_load_rgbe (char const *filename, int *x, int *y, int *comp, int req_comp) |
3547 | { |
3548 | FILE *f = fopen(filename, "rb" ); |
3549 | unsigned char *result; |
3550 | if (!f) return epuc("can't fopen" , "Unable to open file" ); |
3551 | result = stbi_hdr_load_rgbe_file(f,x,y,comp,req_comp); |
3552 | fclose(f); |
3553 | return result; |
3554 | } |
3555 | #endif |
3556 | |
3557 | float *stbi_hdr_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) |
3558 | { |
3559 | stbi s; |
3560 | start_mem(&s,buffer, len); |
3561 | return hdr_load(&s,x,y,comp,req_comp); |
3562 | } |
3563 | |
3564 | stbi_uc *stbi_hdr_load_rgbe_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp) |
3565 | { |
3566 | stbi s; |
3567 | start_mem(&s,buffer, len); |
3568 | return hdr_load_rgbe(&s,x,y,comp,req_comp); |
3569 | } |
3570 | |
3571 | #endif // STBI_NO_HDR |
3572 | |
3573 | /////////////////////// write image /////////////////////// |
3574 | |
3575 | #ifndef STBI_NO_WRITE |
3576 | |
3577 | static void write8(FILE *f, int x) { uint8 z = (uint8) x; fwrite(&z,1,1,f); } |
3578 | |
3579 | static void writefv(FILE *f, char *fmt, va_list v) |
3580 | { |
3581 | while (*fmt) { |
3582 | switch (*fmt++) { |
3583 | case ' ': break; |
3584 | case '1': { uint8 x = va_arg(v, int); write8(f,x); break; } |
3585 | case '2': { int16 x = va_arg(v, int); write8(f,x); write8(f,x>>8); break; } |
3586 | case '4': { int32 x = va_arg(v, int); write8(f,x); write8(f,x>>8); write8(f,x>>16); write8(f,x>>24); break; } |
3587 | default: |
3588 | assert(0); |
3589 | va_end(v); |
3590 | return; |
3591 | } |
3592 | } |
3593 | } |
3594 | |
3595 | static void writef(FILE *f, char *fmt, ...) |
3596 | { |
3597 | va_list v; |
3598 | va_start(v, fmt); |
3599 | writefv(f,fmt,v); |
3600 | va_end(v); |
3601 | } |
3602 | |
3603 | static void write_pixels(FILE *f, int rgb_dir, int vdir, int x, int y, int comp, void *data, int write_alpha, int scanline_pad) |
3604 | { |
3605 | uint8 bg[3] = { 255, 0, 255}, px[3]; |
3606 | uint32 zero = 0; |
3607 | int i,j,k, j_end; |
3608 | |
3609 | if (vdir < 0) |
3610 | j_end = -1, j = y-1; |
3611 | else |
3612 | j_end = y, j = 0; |
3613 | |
3614 | for (; j != j_end; j += vdir) { |
3615 | for (i=0; i < x; ++i) { |
3616 | uint8 *d = (uint8 *) data + (j*x+i)*comp; |
3617 | if (write_alpha < 0) |
3618 | fwrite(&d[comp-1], 1, 1, f); |
3619 | switch (comp) { |
3620 | case 1: |
3621 | case 2: writef(f, "111" , d[0],d[0],d[0]); |
3622 | break; |
3623 | case 4: |
3624 | if (!write_alpha) { |
3625 | for (k=0; k < 3; ++k) |
3626 | px[k] = bg[k] + ((d[k] - bg[k]) * d[3])/255; |
3627 | writef(f, "111" , px[1-rgb_dir],px[1],px[1+rgb_dir]); |
3628 | break; |
3629 | } |
3630 | /* FALLTHROUGH */ |
3631 | case 3: |
3632 | writef(f, "111" , d[1-rgb_dir],d[1],d[1+rgb_dir]); |
3633 | break; |
3634 | } |
3635 | if (write_alpha > 0) |
3636 | fwrite(&d[comp-1], 1, 1, f); |
3637 | } |
3638 | fwrite(&zero,scanline_pad,1,f); |
3639 | } |
3640 | } |
3641 | |
3642 | static int outfile(char const *filename, int rgb_dir, int vdir, int x, int y, int comp, void *data, int alpha, int pad, char *fmt, ...) |
3643 | { |
3644 | FILE *f = fopen(filename, "wb" ); |
3645 | if (f) { |
3646 | va_list v; |
3647 | va_start(v, fmt); |
3648 | writefv(f, fmt, v); |
3649 | va_end(v); |
3650 | write_pixels(f,rgb_dir,vdir,x,y,comp,data,alpha,pad); |
3651 | fclose(f); |
3652 | } |
3653 | return f != NULL; |
3654 | } |
3655 | |
3656 | int stbi_write_bmp(char const *filename, int x, int y, int comp, void *data) |
3657 | { |
3658 | int pad = (-x*3) & 3; |
3659 | return outfile(filename,-1,-1,x,y,comp,data,0,pad, |
3660 | "11 4 22 4" "4 44 22 444444" , |
3661 | 'B', 'M', 14+40+(x*3+pad)*y, 0,0, 14+40, // file header |
3662 | 40, x,y, 1,24, 0,0,0,0,0,0); // bitmap header |
3663 | } |
3664 | |
3665 | int stbi_write_tga(char const *filename, int x, int y, int comp, void *data) |
3666 | { |
3667 | int has_alpha = !(comp & 1); |
3668 | return outfile(filename, -1,-1, x, y, comp, data, has_alpha, 0, |
3669 | "111 221 2222 11" , 0,0,2, 0,0,0, 0,0,x,y, 24+8*has_alpha, 8*has_alpha); |
3670 | } |
3671 | |
3672 | // any other image formats that do interleaved rgb data? |
3673 | // PNG: requires adler32,crc32 -- significant amount of code |
3674 | // PSD: no, channels output separately |
3675 | // TIFF: no, stripwise-interleaved... i think |
3676 | |
3677 | #endif // STBI_NO_WRITE |
3678 | |
3679 | // add in my DDS loading support |
3680 | #ifndef STBI_NO_DDS |
3681 | #include "stbi_DDS_aug_c.h" |
3682 | #endif |
3683 | |