Line data Source code
1 :
2 : /* pngtrans.c - transforms the data in a row (used by both readers and writers)
3 : *
4 : * Last changed in libpng 1.6.26 [October 20, 2016]
5 : * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
6 : * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 : * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8 : *
9 : * This code is released under the libpng license.
10 : * For conditions of distribution and use, see the disclaimer
11 : * and license in png.h
12 : */
13 :
14 : #include "pngpriv.h"
15 :
16 : #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
17 :
18 : #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
19 : /* Turn on BGR-to-RGB mapping */
20 : void PNGAPI
21 : png_set_bgr(png_structrp png_ptr)
22 : {
23 : png_debug(1, "in png_set_bgr");
24 :
25 : if (png_ptr == NULL)
26 : return;
27 :
28 : png_ptr->transformations |= PNG_BGR;
29 : }
30 : #endif
31 :
32 : #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
33 : /* Turn on 16-bit byte swapping */
34 : void PNGAPI
35 : png_set_swap(png_structrp png_ptr)
36 : {
37 : png_debug(1, "in png_set_swap");
38 :
39 : if (png_ptr == NULL)
40 : return;
41 :
42 : if (png_ptr->bit_depth == 16)
43 : png_ptr->transformations |= PNG_SWAP_BYTES;
44 : }
45 : #endif
46 :
47 : #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
48 : /* Turn on pixel packing */
49 : void PNGAPI
50 : png_set_packing(png_structrp png_ptr)
51 : {
52 : png_debug(1, "in png_set_packing");
53 :
54 : if (png_ptr == NULL)
55 : return;
56 :
57 : if (png_ptr->bit_depth < 8)
58 : {
59 : png_ptr->transformations |= PNG_PACK;
60 : # ifdef PNG_WRITE_SUPPORTED
61 : png_ptr->usr_bit_depth = 8;
62 : # endif
63 : }
64 : }
65 : #endif
66 :
67 : #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
68 : /* Turn on packed pixel swapping */
69 : void PNGAPI
70 : png_set_packswap(png_structrp png_ptr)
71 : {
72 : png_debug(1, "in png_set_packswap");
73 :
74 : if (png_ptr == NULL)
75 : return;
76 :
77 : if (png_ptr->bit_depth < 8)
78 : png_ptr->transformations |= PNG_PACKSWAP;
79 : }
80 : #endif
81 :
82 : #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
83 : void PNGAPI
84 : png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits)
85 : {
86 : png_debug(1, "in png_set_shift");
87 :
88 : if (png_ptr == NULL)
89 : return;
90 :
91 : png_ptr->transformations |= PNG_SHIFT;
92 : png_ptr->shift = *true_bits;
93 : }
94 : #endif
95 :
96 : #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
97 : defined(PNG_WRITE_INTERLACING_SUPPORTED)
98 : int PNGAPI
99 0 : png_set_interlace_handling(png_structrp png_ptr)
100 : {
101 : png_debug(1, "in png_set_interlace handling");
102 :
103 0 : if (png_ptr != 0 && png_ptr->interlaced != 0)
104 : {
105 0 : png_ptr->transformations |= PNG_INTERLACE;
106 0 : return (7);
107 : }
108 :
109 0 : return (1);
110 : }
111 : #endif
112 :
113 : #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
114 : /* Add a filler byte on read, or remove a filler or alpha byte on write.
115 : * The filler type has changed in v0.95 to allow future 2-byte fillers
116 : * for 48-bit input data, as well as to avoid problems with some compilers
117 : * that don't like bytes as parameters.
118 : */
119 : void PNGAPI
120 : png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
121 : {
122 : png_debug(1, "in png_set_filler");
123 :
124 : if (png_ptr == NULL)
125 : return;
126 :
127 : /* In libpng 1.6 it is possible to determine whether this is a read or write
128 : * operation and therefore to do more checking here for a valid call.
129 : */
130 : if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
131 : {
132 : # ifdef PNG_READ_FILLER_SUPPORTED
133 : /* On read png_set_filler is always valid, regardless of the base PNG
134 : * format, because other transformations can give a format where the
135 : * filler code can execute (basically an 8 or 16-bit component RGB or G
136 : * format.)
137 : *
138 : * NOTE: usr_channels is not used by the read code! (This has led to
139 : * confusion in the past.) The filler is only used in the read code.
140 : */
141 : png_ptr->filler = (png_uint_16)filler;
142 : # else
143 : png_app_error(png_ptr, "png_set_filler not supported on read");
144 : PNG_UNUSED(filler) /* not used in the write case */
145 : return;
146 : # endif
147 : }
148 :
149 : else /* write */
150 : {
151 : # ifdef PNG_WRITE_FILLER_SUPPORTED
152 : /* On write the usr_channels parameter must be set correctly at the
153 : * start to record the number of channels in the app-supplied data.
154 : */
155 : switch (png_ptr->color_type)
156 : {
157 : case PNG_COLOR_TYPE_RGB:
158 : png_ptr->usr_channels = 4;
159 : break;
160 :
161 : case PNG_COLOR_TYPE_GRAY:
162 : if (png_ptr->bit_depth >= 8)
163 : {
164 : png_ptr->usr_channels = 2;
165 : break;
166 : }
167 :
168 : else
169 : {
170 : /* There simply isn't any code in libpng to strip out bits
171 : * from bytes when the components are less than a byte in
172 : * size!
173 : */
174 : png_app_error(png_ptr,
175 : "png_set_filler is invalid for"
176 : " low bit depth gray output");
177 : return;
178 : }
179 :
180 : default:
181 : png_app_error(png_ptr,
182 : "png_set_filler: inappropriate color type");
183 : return;
184 : }
185 : # else
186 : png_app_error(png_ptr, "png_set_filler not supported on write");
187 : return;
188 : # endif
189 : }
190 :
191 : /* Here on success - libpng supports the operation, set the transformation
192 : * and the flag to say where the filler channel is.
193 : */
194 : png_ptr->transformations |= PNG_FILLER;
195 :
196 : if (filler_loc == PNG_FILLER_AFTER)
197 : png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
198 :
199 : else
200 : png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
201 : }
202 :
203 : /* Added to libpng-1.2.7 */
204 : void PNGAPI
205 : png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
206 : {
207 : png_debug(1, "in png_set_add_alpha");
208 :
209 : if (png_ptr == NULL)
210 : return;
211 :
212 : png_set_filler(png_ptr, filler, filler_loc);
213 : /* The above may fail to do anything. */
214 : if ((png_ptr->transformations & PNG_FILLER) != 0)
215 : png_ptr->transformations |= PNG_ADD_ALPHA;
216 : }
217 :
218 : #endif
219 :
220 : #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
221 : defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
222 : void PNGAPI
223 : png_set_swap_alpha(png_structrp png_ptr)
224 : {
225 : png_debug(1, "in png_set_swap_alpha");
226 :
227 : if (png_ptr == NULL)
228 : return;
229 :
230 : png_ptr->transformations |= PNG_SWAP_ALPHA;
231 : }
232 : #endif
233 :
234 : #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
235 : defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
236 : void PNGAPI
237 : png_set_invert_alpha(png_structrp png_ptr)
238 : {
239 : png_debug(1, "in png_set_invert_alpha");
240 :
241 : if (png_ptr == NULL)
242 : return;
243 :
244 : png_ptr->transformations |= PNG_INVERT_ALPHA;
245 : }
246 : #endif
247 :
248 : #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
249 : void PNGAPI
250 : png_set_invert_mono(png_structrp png_ptr)
251 : {
252 : png_debug(1, "in png_set_invert_mono");
253 :
254 : if (png_ptr == NULL)
255 : return;
256 :
257 : png_ptr->transformations |= PNG_INVERT_MONO;
258 : }
259 :
260 : /* Invert monochrome grayscale data */
261 : void /* PRIVATE */
262 : png_do_invert(png_row_infop row_info, png_bytep row)
263 : {
264 : png_debug(1, "in png_do_invert");
265 :
266 : /* This test removed from libpng version 1.0.13 and 1.2.0:
267 : * if (row_info->bit_depth == 1 &&
268 : */
269 : if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
270 : {
271 : png_bytep rp = row;
272 : png_size_t i;
273 : png_size_t istop = row_info->rowbytes;
274 :
275 : for (i = 0; i < istop; i++)
276 : {
277 : *rp = (png_byte)(~(*rp));
278 : rp++;
279 : }
280 : }
281 :
282 : else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
283 : row_info->bit_depth == 8)
284 : {
285 : png_bytep rp = row;
286 : png_size_t i;
287 : png_size_t istop = row_info->rowbytes;
288 :
289 : for (i = 0; i < istop; i += 2)
290 : {
291 : *rp = (png_byte)(~(*rp));
292 : rp += 2;
293 : }
294 : }
295 :
296 : #ifdef PNG_16BIT_SUPPORTED
297 : else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
298 : row_info->bit_depth == 16)
299 : {
300 : png_bytep rp = row;
301 : png_size_t i;
302 : png_size_t istop = row_info->rowbytes;
303 :
304 : for (i = 0; i < istop; i += 4)
305 : {
306 : *rp = (png_byte)(~(*rp));
307 : *(rp + 1) = (png_byte)(~(*(rp + 1)));
308 : rp += 4;
309 : }
310 : }
311 : #endif
312 : }
313 : #endif
314 :
315 : #ifdef PNG_16BIT_SUPPORTED
316 : #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
317 : /* Swaps byte order on 16-bit depth images */
318 : void /* PRIVATE */
319 : png_do_swap(png_row_infop row_info, png_bytep row)
320 : {
321 : png_debug(1, "in png_do_swap");
322 :
323 : if (row_info->bit_depth == 16)
324 : {
325 : png_bytep rp = row;
326 : png_uint_32 i;
327 : png_uint_32 istop= row_info->width * row_info->channels;
328 :
329 : for (i = 0; i < istop; i++, rp += 2)
330 : {
331 : #ifdef PNG_BUILTIN_BSWAP16_SUPPORTED
332 : /* Feature added to libpng-1.6.11 for testing purposes, not
333 : * enabled by default.
334 : */
335 : *(png_uint_16*)rp = __builtin_bswap16(*(png_uint_16*)rp);
336 : #else
337 : png_byte t = *rp;
338 : *rp = *(rp + 1);
339 : *(rp + 1) = t;
340 : #endif
341 : }
342 : }
343 : }
344 : #endif
345 : #endif
346 :
347 : #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
348 : static PNG_CONST png_byte onebppswaptable[256] = {
349 : 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
350 : 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
351 : 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
352 : 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
353 : 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4,
354 : 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
355 : 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,
356 : 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
357 : 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,
358 : 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
359 : 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA,
360 : 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
361 : 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6,
362 : 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
363 : 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,
364 : 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
365 : 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,
366 : 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
367 : 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9,
368 : 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
369 : 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
370 : 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
371 : 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED,
372 : 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
373 : 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3,
374 : 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
375 : 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,
376 : 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
377 : 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7,
378 : 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
379 : 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF,
380 : 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
381 : };
382 :
383 : static PNG_CONST png_byte twobppswaptable[256] = {
384 : 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,
385 : 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,
386 : 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,
387 : 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4,
388 : 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8,
389 : 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8,
390 : 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC,
391 : 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC,
392 : 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1,
393 : 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1,
394 : 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5,
395 : 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5,
396 : 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9,
397 : 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9,
398 : 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD,
399 : 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD,
400 : 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2,
401 : 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2,
402 : 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6,
403 : 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6,
404 : 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA,
405 : 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA,
406 : 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE,
407 : 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE,
408 : 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3,
409 : 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3,
410 : 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7,
411 : 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7,
412 : 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB,
413 : 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB,
414 : 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF,
415 : 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF
416 : };
417 :
418 : static PNG_CONST png_byte fourbppswaptable[256] = {
419 : 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
420 : 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,
421 : 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,
422 : 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1,
423 : 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72,
424 : 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2,
425 : 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73,
426 : 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3,
427 : 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74,
428 : 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4,
429 : 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75,
430 : 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5,
431 : 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76,
432 : 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6,
433 : 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77,
434 : 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7,
435 : 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78,
436 : 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8,
437 : 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79,
438 : 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9,
439 : 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A,
440 : 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA,
441 : 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B,
442 : 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB,
443 : 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C,
444 : 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC,
445 : 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D,
446 : 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD,
447 : 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E,
448 : 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE,
449 : 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F,
450 : 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF
451 : };
452 :
453 : /* Swaps pixel packing order within bytes */
454 : void /* PRIVATE */
455 : png_do_packswap(png_row_infop row_info, png_bytep row)
456 : {
457 : png_debug(1, "in png_do_packswap");
458 :
459 : if (row_info->bit_depth < 8)
460 : {
461 : png_bytep rp;
462 : png_const_bytep end, table;
463 :
464 : end = row + row_info->rowbytes;
465 :
466 : if (row_info->bit_depth == 1)
467 : table = onebppswaptable;
468 :
469 : else if (row_info->bit_depth == 2)
470 : table = twobppswaptable;
471 :
472 : else if (row_info->bit_depth == 4)
473 : table = fourbppswaptable;
474 :
475 : else
476 : return;
477 :
478 : for (rp = row; rp < end; rp++)
479 : *rp = table[*rp];
480 : }
481 : }
482 : #endif /* PACKSWAP || WRITE_PACKSWAP */
483 :
484 : #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
485 : defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
486 : /* Remove a channel - this used to be 'png_do_strip_filler' but it used a
487 : * somewhat weird combination of flags to determine what to do. All the calls
488 : * to png_do_strip_filler are changed in 1.5.2 to call this instead with the
489 : * correct arguments.
490 : *
491 : * The routine isn't general - the channel must be the channel at the start or
492 : * end (not in the middle) of each pixel.
493 : */
494 : void /* PRIVATE */
495 : png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
496 : {
497 : png_bytep sp = row; /* source pointer */
498 : png_bytep dp = row; /* destination pointer */
499 : png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */
500 :
501 : /* At the start sp will point to the first byte to copy and dp to where
502 : * it is copied to. ep always points just beyond the end of the row, so
503 : * the loop simply copies (channels-1) channels until sp reaches ep.
504 : *
505 : * at_start: 0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
506 : * nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
507 : */
508 :
509 : /* GA, GX, XG cases */
510 : if (row_info->channels == 2)
511 : {
512 : if (row_info->bit_depth == 8)
513 : {
514 : if (at_start != 0) /* Skip initial filler */
515 : ++sp;
516 : else /* Skip initial channel and, for sp, the filler */
517 : sp += 2, ++dp;
518 :
519 : /* For a 1 pixel wide image there is nothing to do */
520 : while (sp < ep)
521 : *dp++ = *sp, sp += 2;
522 :
523 : row_info->pixel_depth = 8;
524 : }
525 :
526 : else if (row_info->bit_depth == 16)
527 : {
528 : if (at_start != 0) /* Skip initial filler */
529 : sp += 2;
530 : else /* Skip initial channel and, for sp, the filler */
531 : sp += 4, dp += 2;
532 :
533 : while (sp < ep)
534 : *dp++ = *sp++, *dp++ = *sp, sp += 3;
535 :
536 : row_info->pixel_depth = 16;
537 : }
538 :
539 : else
540 : return; /* bad bit depth */
541 :
542 : row_info->channels = 1;
543 :
544 : /* Finally fix the color type if it records an alpha channel */
545 : if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
546 : row_info->color_type = PNG_COLOR_TYPE_GRAY;
547 : }
548 :
549 : /* RGBA, RGBX, XRGB cases */
550 : else if (row_info->channels == 4)
551 : {
552 : if (row_info->bit_depth == 8)
553 : {
554 : if (at_start != 0) /* Skip initial filler */
555 : ++sp;
556 : else /* Skip initial channels and, for sp, the filler */
557 : sp += 4, dp += 3;
558 :
559 : /* Note that the loop adds 3 to dp and 4 to sp each time. */
560 : while (sp < ep)
561 : *dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2;
562 :
563 : row_info->pixel_depth = 24;
564 : }
565 :
566 : else if (row_info->bit_depth == 16)
567 : {
568 : if (at_start != 0) /* Skip initial filler */
569 : sp += 2;
570 : else /* Skip initial channels and, for sp, the filler */
571 : sp += 8, dp += 6;
572 :
573 : while (sp < ep)
574 : {
575 : /* Copy 6 bytes, skip 2 */
576 : *dp++ = *sp++, *dp++ = *sp++;
577 : *dp++ = *sp++, *dp++ = *sp++;
578 : *dp++ = *sp++, *dp++ = *sp, sp += 3;
579 : }
580 :
581 : row_info->pixel_depth = 48;
582 : }
583 :
584 : else
585 : return; /* bad bit depth */
586 :
587 : row_info->channels = 3;
588 :
589 : /* Finally fix the color type if it records an alpha channel */
590 : if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
591 : row_info->color_type = PNG_COLOR_TYPE_RGB;
592 : }
593 :
594 : else
595 : return; /* The filler channel has gone already */
596 :
597 : /* Fix the rowbytes value. */
598 : row_info->rowbytes = (unsigned int)(dp-row);
599 : }
600 : #endif
601 :
602 : #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
603 : /* Swaps red and blue bytes within a pixel */
604 : void /* PRIVATE */
605 : png_do_bgr(png_row_infop row_info, png_bytep row)
606 : {
607 : png_debug(1, "in png_do_bgr");
608 :
609 : if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
610 : {
611 : png_uint_32 row_width = row_info->width;
612 : if (row_info->bit_depth == 8)
613 : {
614 : if (row_info->color_type == PNG_COLOR_TYPE_RGB)
615 : {
616 : png_bytep rp;
617 : png_uint_32 i;
618 :
619 : for (i = 0, rp = row; i < row_width; i++, rp += 3)
620 : {
621 : png_byte save = *rp;
622 : *rp = *(rp + 2);
623 : *(rp + 2) = save;
624 : }
625 : }
626 :
627 : else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
628 : {
629 : png_bytep rp;
630 : png_uint_32 i;
631 :
632 : for (i = 0, rp = row; i < row_width; i++, rp += 4)
633 : {
634 : png_byte save = *rp;
635 : *rp = *(rp + 2);
636 : *(rp + 2) = save;
637 : }
638 : }
639 : }
640 :
641 : #ifdef PNG_16BIT_SUPPORTED
642 : else if (row_info->bit_depth == 16)
643 : {
644 : if (row_info->color_type == PNG_COLOR_TYPE_RGB)
645 : {
646 : png_bytep rp;
647 : png_uint_32 i;
648 :
649 : for (i = 0, rp = row; i < row_width; i++, rp += 6)
650 : {
651 : png_byte save = *rp;
652 : *rp = *(rp + 4);
653 : *(rp + 4) = save;
654 : save = *(rp + 1);
655 : *(rp + 1) = *(rp + 5);
656 : *(rp + 5) = save;
657 : }
658 : }
659 :
660 : else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
661 : {
662 : png_bytep rp;
663 : png_uint_32 i;
664 :
665 : for (i = 0, rp = row; i < row_width; i++, rp += 8)
666 : {
667 : png_byte save = *rp;
668 : *rp = *(rp + 4);
669 : *(rp + 4) = save;
670 : save = *(rp + 1);
671 : *(rp + 1) = *(rp + 5);
672 : *(rp + 5) = save;
673 : }
674 : }
675 : }
676 : #endif
677 : }
678 : }
679 : #endif /* READ_BGR || WRITE_BGR */
680 :
681 : #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
682 : defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
683 : /* Added at libpng-1.5.10 */
684 : void /* PRIVATE */
685 : png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info)
686 : {
687 : if (png_ptr->num_palette < (1 << row_info->bit_depth) &&
688 : png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */
689 : {
690 : /* Calculations moved outside switch in an attempt to stop different
691 : * compiler warnings. 'padding' is in *bits* within the last byte, it is
692 : * an 'int' because pixel_depth becomes an 'int' in the expression below,
693 : * and this calculation is used because it avoids warnings that other
694 : * forms produced on either GCC or MSVC.
695 : */
696 : int padding = PNG_PADBITS(row_info->pixel_depth, row_info->width);
697 : png_bytep rp = png_ptr->row_buf + row_info->rowbytes;
698 :
699 : switch (row_info->bit_depth)
700 : {
701 : case 1:
702 : {
703 : /* in this case, all bytes must be 0 so we don't need
704 : * to unpack the pixels except for the rightmost one.
705 : */
706 : for (; rp > png_ptr->row_buf; rp--)
707 : {
708 : if ((*rp >> padding) != 0)
709 : png_ptr->num_palette_max = 1;
710 : padding = 0;
711 : }
712 :
713 : break;
714 : }
715 :
716 : case 2:
717 : {
718 : for (; rp > png_ptr->row_buf; rp--)
719 : {
720 : int i = ((*rp >> padding) & 0x03);
721 :
722 : if (i > png_ptr->num_palette_max)
723 : png_ptr->num_palette_max = i;
724 :
725 : i = (((*rp >> padding) >> 2) & 0x03);
726 :
727 : if (i > png_ptr->num_palette_max)
728 : png_ptr->num_palette_max = i;
729 :
730 : i = (((*rp >> padding) >> 4) & 0x03);
731 :
732 : if (i > png_ptr->num_palette_max)
733 : png_ptr->num_palette_max = i;
734 :
735 : i = (((*rp >> padding) >> 6) & 0x03);
736 :
737 : if (i > png_ptr->num_palette_max)
738 : png_ptr->num_palette_max = i;
739 :
740 : padding = 0;
741 : }
742 :
743 : break;
744 : }
745 :
746 : case 4:
747 : {
748 : for (; rp > png_ptr->row_buf; rp--)
749 : {
750 : int i = ((*rp >> padding) & 0x0f);
751 :
752 : if (i > png_ptr->num_palette_max)
753 : png_ptr->num_palette_max = i;
754 :
755 : i = (((*rp >> padding) >> 4) & 0x0f);
756 :
757 : if (i > png_ptr->num_palette_max)
758 : png_ptr->num_palette_max = i;
759 :
760 : padding = 0;
761 : }
762 :
763 : break;
764 : }
765 :
766 : case 8:
767 : {
768 : for (; rp > png_ptr->row_buf; rp--)
769 : {
770 : if (*rp > png_ptr->num_palette_max)
771 : png_ptr->num_palette_max = (int) *rp;
772 : }
773 :
774 : break;
775 : }
776 :
777 : default:
778 : break;
779 : }
780 : }
781 : }
782 : #endif /* CHECK_FOR_INVALID_INDEX */
783 :
784 : #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
785 : defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
786 : #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
787 : void PNGAPI
788 : png_set_user_transform_info(png_structrp png_ptr, png_voidp
789 : user_transform_ptr, int user_transform_depth, int user_transform_channels)
790 : {
791 : png_debug(1, "in png_set_user_transform_info");
792 :
793 : if (png_ptr == NULL)
794 : return;
795 :
796 : #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
797 : if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
798 : (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
799 : {
800 : png_app_error(png_ptr,
801 : "info change after png_start_read_image or png_read_update_info");
802 : return;
803 : }
804 : #endif
805 :
806 : png_ptr->user_transform_ptr = user_transform_ptr;
807 : png_ptr->user_transform_depth = (png_byte)user_transform_depth;
808 : png_ptr->user_transform_channels = (png_byte)user_transform_channels;
809 : }
810 : #endif
811 :
812 : /* This function returns a pointer to the user_transform_ptr associated with
813 : * the user transform functions. The application should free any memory
814 : * associated with this pointer before png_write_destroy and png_read_destroy
815 : * are called.
816 : */
817 : #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
818 : png_voidp PNGAPI
819 : png_get_user_transform_ptr(png_const_structrp png_ptr)
820 : {
821 : if (png_ptr == NULL)
822 : return (NULL);
823 :
824 : return png_ptr->user_transform_ptr;
825 : }
826 : #endif
827 :
828 : #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
829 : png_uint_32 PNGAPI
830 : png_get_current_row_number(png_const_structrp png_ptr)
831 : {
832 : /* See the comments in png.h - this is the sub-image row when reading an
833 : * interlaced image.
834 : */
835 : if (png_ptr != NULL)
836 : return png_ptr->row_number;
837 :
838 : return PNG_UINT_32_MAX; /* help the app not to fail silently */
839 : }
840 :
841 : png_byte PNGAPI
842 : png_get_current_pass_number(png_const_structrp png_ptr)
843 : {
844 : if (png_ptr != NULL)
845 : return png_ptr->pass;
846 : return 8; /* invalid */
847 : }
848 : #endif /* USER_TRANSFORM_INFO */
849 : #endif /* READ_USER_TRANSFORM || WRITE_USER_TRANSFORM */
850 : #endif /* READ || WRITE */
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