OLD | NEW |
1 /* | 1 /* |
2 * Copyright 2006 The Android Open Source Project | 2 * Copyright 2006 The Android Open Source Project |
3 * | 3 * |
4 * Use of this source code is governed by a BSD-style license that can be | 4 * Use of this source code is governed by a BSD-style license that can be |
5 * found in the LICENSE file. | 5 * found in the LICENSE file. |
6 */ | 6 */ |
7 | 7 |
8 #include "SkImageDecoder.h" | |
9 #include "SkImageEncoder.h" | 8 #include "SkImageEncoder.h" |
10 #include "SkColor.h" | 9 #include "SkColor.h" |
11 #include "SkColorPriv.h" | 10 #include "SkColorPriv.h" |
12 #include "SkDither.h" | 11 #include "SkDither.h" |
13 #include "SkMath.h" | 12 #include "SkMath.h" |
14 #include "SkRTConf.h" | 13 #include "SkRTConf.h" |
15 #include "SkScaledBitmapSampler.h" | |
16 #include "SkStream.h" | 14 #include "SkStream.h" |
17 #include "SkTemplates.h" | 15 #include "SkTemplates.h" |
18 #include "SkUtils.h" | 16 #include "SkUtils.h" |
19 #include "transform_scanline.h" | 17 #include "transform_scanline.h" |
20 | 18 |
21 #include "png.h" | 19 #include "png.h" |
22 | 20 |
23 /* These were dropped in libpng >= 1.4 */ | 21 /* These were dropped in libpng >= 1.4 */ |
24 #ifndef png_infopp_NULL | 22 #ifndef png_infopp_NULL |
25 #define png_infopp_NULL nullptr | 23 #define png_infopp_NULL nullptr |
(...skipping 11 matching lines...) Expand all Loading... |
37 #define png_flush_ptr_NULL nullptr | 35 #define png_flush_ptr_NULL nullptr |
38 #endif | 36 #endif |
39 | 37 |
40 #define DEFAULT_FOR_SUPPRESS_PNG_IMAGE_DECODER_WARNINGS true | 38 #define DEFAULT_FOR_SUPPRESS_PNG_IMAGE_DECODER_WARNINGS true |
41 SK_CONF_DECLARE(bool, c_suppressPNGImageDecoderWarnings, | 39 SK_CONF_DECLARE(bool, c_suppressPNGImageDecoderWarnings, |
42 "images.png.suppressDecoderWarnings", | 40 "images.png.suppressDecoderWarnings", |
43 DEFAULT_FOR_SUPPRESS_PNG_IMAGE_DECODER_WARNINGS, | 41 DEFAULT_FOR_SUPPRESS_PNG_IMAGE_DECODER_WARNINGS, |
44 "Suppress most PNG warnings when calling image decode " | 42 "Suppress most PNG warnings when calling image decode " |
45 "functions."); | 43 "functions."); |
46 | 44 |
47 class SkPNGImageIndex { | 45 /////////////////////////////////////////////////////////////////////////////// |
48 public: | |
49 // Takes ownership of stream. | |
50 SkPNGImageIndex(SkStreamRewindable* stream, png_structp png_ptr, png_infop i
nfo_ptr) | |
51 : fStream(stream) | |
52 , fPng_ptr(png_ptr) | |
53 , fInfo_ptr(info_ptr) | |
54 , fColorType(kUnknown_SkColorType) { | |
55 SkASSERT(stream != nullptr); | |
56 } | |
57 ~SkPNGImageIndex() { | |
58 if (fPng_ptr) { | |
59 png_destroy_read_struct(&fPng_ptr, &fInfo_ptr, png_infopp_NULL); | |
60 } | |
61 } | |
62 | 46 |
63 SkAutoTDelete<SkStreamRewindable> fStream; | 47 #include "SkColorPriv.h" |
64 png_structp fPng_ptr; | 48 #include "SkUnPreMultiply.h" |
65 png_infop fInfo_ptr; | |
66 SkColorType fColorType; | |
67 }; | |
68 | |
69 class SkPNGImageDecoder : public SkImageDecoder { | |
70 public: | |
71 SkPNGImageDecoder() { | |
72 fImageIndex = nullptr; | |
73 } | |
74 Format getFormat() const override { | |
75 return kPNG_Format; | |
76 } | |
77 | |
78 virtual ~SkPNGImageDecoder() { delete fImageIndex; } | |
79 | |
80 protected: | |
81 Result onDecode(SkStream* stream, SkBitmap* bm, Mode) override; | |
82 | |
83 private: | |
84 SkPNGImageIndex* fImageIndex; | |
85 | |
86 bool onDecodeInit(SkStream* stream, png_structp *png_ptrp, png_infop *info_p
trp); | |
87 bool decodePalette(png_structp png_ptr, png_infop info_ptr, int bitDepth, | |
88 bool * SK_RESTRICT hasAlphap, bool *reallyHasAlphap, | |
89 SkColorTable **colorTablep); | |
90 bool getBitmapColorType(png_structp, png_infop, SkColorType*, bool* hasAlpha
, | |
91 SkPMColor* theTranspColor); | |
92 | |
93 typedef SkImageDecoder INHERITED; | |
94 }; | |
95 | |
96 #ifndef png_jmpbuf | |
97 # define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf) | |
98 #endif | |
99 | |
100 #define PNG_BYTES_TO_CHECK 4 | |
101 | |
102 /* Automatically clean up after throwing an exception */ | |
103 struct PNGAutoClean { | |
104 PNGAutoClean(png_structp p, png_infop i): png_ptr(p), info_ptr(i) {} | |
105 ~PNGAutoClean() { | |
106 png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL); | |
107 } | |
108 private: | |
109 png_structp png_ptr; | |
110 png_infop info_ptr; | |
111 }; | |
112 | |
113 static void sk_read_fn(png_structp png_ptr, png_bytep data, png_size_t length) { | |
114 SkStream* sk_stream = (SkStream*) png_get_io_ptr(png_ptr); | |
115 size_t bytes = sk_stream->read(data, length); | |
116 if (bytes != length) { | |
117 png_error(png_ptr, "Read Error!"); | |
118 } | |
119 } | |
120 | |
121 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED | |
122 static int sk_read_user_chunk(png_structp png_ptr, png_unknown_chunkp chunk) { | |
123 SkPngChunkReader* peeker = (SkPngChunkReader*)png_get_user_chunk_ptr(png_ptr
); | |
124 // readChunk() returning true means continue decoding | |
125 return peeker->readChunk((const char*)chunk->name, chunk->data, chunk->size)
? | |
126 1 : -1; | |
127 } | |
128 #endif | |
129 | 49 |
130 static void sk_error_fn(png_structp png_ptr, png_const_charp msg) { | 50 static void sk_error_fn(png_structp png_ptr, png_const_charp msg) { |
131 if (!c_suppressPNGImageDecoderWarnings) { | 51 if (!c_suppressPNGImageDecoderWarnings) { |
132 SkDEBUGF(("------ png error %s\n", msg)); | 52 SkDEBUGF(("------ png error %s\n", msg)); |
133 } | 53 } |
134 longjmp(png_jmpbuf(png_ptr), 1); | 54 longjmp(png_jmpbuf(png_ptr), 1); |
135 } | 55 } |
136 | 56 |
137 static void skip_src_rows(png_structp png_ptr, uint8_t storage[], int count) { | |
138 for (int i = 0; i < count; i++) { | |
139 uint8_t* tmp = storage; | |
140 png_read_rows(png_ptr, &tmp, png_bytepp_NULL, 1); | |
141 } | |
142 } | |
143 | |
144 static bool pos_le(int value, int max) { | |
145 return value > 0 && value <= max; | |
146 } | |
147 | |
148 static bool substituteTranspColor(SkBitmap* bm, SkPMColor match) { | |
149 SkASSERT(bm->colorType() == kN32_SkColorType); | |
150 | |
151 bool reallyHasAlpha = false; | |
152 | |
153 for (int y = bm->height() - 1; y >= 0; --y) { | |
154 SkPMColor* p = bm->getAddr32(0, y); | |
155 for (int x = bm->width() - 1; x >= 0; --x) { | |
156 if (match == *p) { | |
157 *p = 0; | |
158 reallyHasAlpha = true; | |
159 } | |
160 p += 1; | |
161 } | |
162 } | |
163 return reallyHasAlpha; | |
164 } | |
165 | |
166 static bool canUpscalePaletteToConfig(SkColorType dstColorType, bool srcHasAlpha
) { | |
167 switch (dstColorType) { | |
168 case kN32_SkColorType: | |
169 case kARGB_4444_SkColorType: | |
170 return true; | |
171 case kRGB_565_SkColorType: | |
172 // only return true if the src is opaque (since 565 is opaque) | |
173 return !srcHasAlpha; | |
174 default: | |
175 return false; | |
176 } | |
177 } | |
178 | |
179 // call only if color_type is PALETTE. Returns true if the ctable has alpha | |
180 static bool hasTransparencyInPalette(png_structp png_ptr, png_infop info_ptr) { | |
181 png_bytep trans; | |
182 int num_trans; | |
183 | |
184 if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) { | |
185 png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, nullptr); | |
186 return num_trans > 0; | |
187 } | |
188 return false; | |
189 } | |
190 | |
191 void do_nothing_warning_fn(png_structp, png_const_charp) { | |
192 /* do nothing */ | |
193 } | |
194 | |
195 bool SkPNGImageDecoder::onDecodeInit(SkStream* sk_stream, png_structp *png_ptrp, | |
196 png_infop *info_ptrp) { | |
197 /* Create and initialize the png_struct with the desired error handler | |
198 * functions. If you want to use the default stderr and longjump method, | |
199 * you can supply nullptr for the last three parameters. We also supply the | |
200 * the compiler header file version, so that we know if the application | |
201 * was compiled with a compatible version of the library. */ | |
202 | |
203 png_error_ptr user_warning_fn = | |
204 (c_suppressPNGImageDecoderWarnings) ? (&do_nothing_warning_fn) : nullptr
; | |
205 /* nullptr means to leave as default library behavior. */ | |
206 /* c_suppressPNGImageDecoderWarnings default depends on SK_DEBUG. */ | |
207 /* To suppress warnings with a SK_DEBUG binary, set the | |
208 * environment variable "skia_images_png_suppressDecoderWarnings" | |
209 * to "true". Inside a program that links to skia: | |
210 * SK_CONF_SET("images.png.suppressDecoderWarnings", true); */ | |
211 | |
212 png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, | |
213 nullptr, sk_error_fn, user_warning_fn); | |
214 // png_voidp user_error_ptr, user_error_fn, user_warning_fn); | |
215 if (png_ptr == nullptr) { | |
216 return false; | |
217 } | |
218 | |
219 *png_ptrp = png_ptr; | |
220 | |
221 /* Allocate/initialize the memory for image information. */ | |
222 png_infop info_ptr = png_create_info_struct(png_ptr); | |
223 if (info_ptr == nullptr) { | |
224 png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL); | |
225 return false; | |
226 } | |
227 *info_ptrp = info_ptr; | |
228 | |
229 /* Set error handling if you are using the setjmp/longjmp method (this is | |
230 * the normal method of doing things with libpng). REQUIRED unless you | |
231 * set up your own error handlers in the png_create_read_struct() earlier. | |
232 */ | |
233 if (setjmp(png_jmpbuf(png_ptr))) { | |
234 png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL); | |
235 return false; | |
236 } | |
237 | |
238 /* If you are using replacement read functions, instead of calling | |
239 * png_init_io() here you would call: | |
240 */ | |
241 png_set_read_fn(png_ptr, (void *)sk_stream, sk_read_fn); | |
242 /* where user_io_ptr is a structure you want available to the callbacks */ | |
243 /* If we have already read some of the signature */ | |
244 // png_set_sig_bytes(png_ptr, 0 /* sig_read */ ); | |
245 | |
246 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED | |
247 // hookup our peeker so we can see any user-chunks the caller may be interes
ted in | |
248 png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_ALWAYS, (png_byte*)"",
0); | |
249 if (this->getPeeker()) { | |
250 png_set_read_user_chunk_fn(png_ptr, (png_voidp)this->getPeeker(), sk_rea
d_user_chunk); | |
251 } | |
252 #endif | |
253 /* The call to png_read_info() gives us all of the information from the | |
254 * PNG file before the first IDAT (image data chunk). */ | |
255 png_read_info(png_ptr, info_ptr); | |
256 png_uint_32 origWidth, origHeight; | |
257 int bitDepth, colorType; | |
258 png_get_IHDR(png_ptr, info_ptr, &origWidth, &origHeight, &bitDepth, | |
259 &colorType, int_p_NULL, int_p_NULL, int_p_NULL); | |
260 | |
261 /* tell libpng to strip 16 bit/color files down to 8 bits/color */ | |
262 if (bitDepth == 16) { | |
263 png_set_strip_16(png_ptr); | |
264 } | |
265 #ifdef PNG_READ_PACK_SUPPORTED | |
266 /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single | |
267 * byte into separate bytes (useful for paletted and grayscale images). */ | |
268 if (bitDepth < 8) { | |
269 png_set_packing(png_ptr); | |
270 } | |
271 #endif | |
272 /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */ | |
273 if (colorType == PNG_COLOR_TYPE_GRAY && bitDepth < 8) { | |
274 png_set_expand_gray_1_2_4_to_8(png_ptr); | |
275 } | |
276 | |
277 return true; | |
278 } | |
279 | |
280 SkImageDecoder::Result SkPNGImageDecoder::onDecode(SkStream* sk_stream, SkBitmap
* decodedBitmap, | |
281 Mode mode) { | |
282 png_structp png_ptr; | |
283 png_infop info_ptr; | |
284 | |
285 if (!onDecodeInit(sk_stream, &png_ptr, &info_ptr)) { | |
286 return kFailure; | |
287 } | |
288 | |
289 PNGAutoClean autoClean(png_ptr, info_ptr); | |
290 | |
291 if (setjmp(png_jmpbuf(png_ptr))) { | |
292 return kFailure; | |
293 } | |
294 | |
295 png_uint_32 origWidth, origHeight; | |
296 int bitDepth, pngColorType, interlaceType; | |
297 png_get_IHDR(png_ptr, info_ptr, &origWidth, &origHeight, &bitDepth, | |
298 &pngColorType, &interlaceType, int_p_NULL, int_p_NULL); | |
299 | |
300 SkColorType colorType; | |
301 bool hasAlpha = false; | |
302 SkPMColor theTranspColor = 0; // 0 tells us not to try to match | |
303 | |
304 if (!this->getBitmapColorType(png_ptr, info_ptr, &colorType, &hasAlpha, &the
TranspColor)) { | |
305 return kFailure; | |
306 } | |
307 | |
308 SkAlphaType alphaType = this->getRequireUnpremultipliedColors() ? | |
309 kUnpremul_SkAlphaType : kPremul_SkAlphaType; | |
310 const int sampleSize = this->getSampleSize(); | |
311 SkScaledBitmapSampler sampler(origWidth, origHeight, sampleSize); | |
312 decodedBitmap->setInfo(SkImageInfo::Make(sampler.scaledWidth(), sampler.scal
edHeight(), | |
313 colorType, alphaType)); | |
314 | |
315 if (SkImageDecoder::kDecodeBounds_Mode == mode) { | |
316 return kSuccess; | |
317 } | |
318 | |
319 // from here down we are concerned with colortables and pixels | |
320 | |
321 // we track if we actually see a non-opaque pixels, since sometimes a PNG se
ts its colortype | |
322 // to |= PNG_COLOR_MASK_ALPHA, but all of its pixels are in fact opaque. We
care, since we | |
323 // draw lots faster if we can flag the bitmap has being opaque | |
324 bool reallyHasAlpha = false; | |
325 SkColorTable* colorTable = nullptr; | |
326 | |
327 if (pngColorType == PNG_COLOR_TYPE_PALETTE) { | |
328 decodePalette(png_ptr, info_ptr, bitDepth, &hasAlpha, &reallyHasAlpha, &
colorTable); | |
329 } | |
330 | |
331 SkAutoUnref aur(colorTable); | |
332 | |
333 if (!this->allocPixelRef(decodedBitmap, | |
334 kIndex_8_SkColorType == colorType ? colorTable : nu
llptr)) { | |
335 return kFailure; | |
336 } | |
337 | |
338 SkAutoLockPixels alp(*decodedBitmap); | |
339 | |
340 // Repeat setjmp, otherwise variables declared since the last call (e.g. alp | |
341 // and aur) won't get their destructors called in case of a failure. | |
342 if (setjmp(png_jmpbuf(png_ptr))) { | |
343 return kFailure; | |
344 } | |
345 | |
346 /* Turn on interlace handling. REQUIRED if you are not using | |
347 * png_read_image(). To see how to handle interlacing passes, | |
348 * see the png_read_row() method below: | |
349 */ | |
350 const int number_passes = (interlaceType != PNG_INTERLACE_NONE) ? | |
351 png_set_interlace_handling(png_ptr) : 1; | |
352 | |
353 /* Optional call to gamma correct and add the background to the palette | |
354 * and update info structure. REQUIRED if you are expecting libpng to | |
355 * update the palette for you (ie you selected such a transform above). | |
356 */ | |
357 png_read_update_info(png_ptr, info_ptr); | |
358 | |
359 if ((kAlpha_8_SkColorType == colorType || kIndex_8_SkColorType == colorType)
&& | |
360 1 == sampleSize) { | |
361 if (kAlpha_8_SkColorType == colorType) { | |
362 // For an A8 bitmap, we assume there is an alpha for speed. It is | |
363 // possible the bitmap is opaque, but that is an unlikely use case | |
364 // since it would not be very interesting. | |
365 reallyHasAlpha = true; | |
366 // A8 is only allowed if the original was GRAY. | |
367 SkASSERT(PNG_COLOR_TYPE_GRAY == pngColorType); | |
368 } | |
369 for (int i = 0; i < number_passes; i++) { | |
370 for (png_uint_32 y = 0; y < origHeight; y++) { | |
371 uint8_t* bmRow = decodedBitmap->getAddr8(0, y); | |
372 png_read_rows(png_ptr, &bmRow, png_bytepp_NULL, 1); | |
373 } | |
374 } | |
375 } else { | |
376 SkScaledBitmapSampler::SrcConfig sc; | |
377 int srcBytesPerPixel = 4; | |
378 | |
379 if (colorTable != nullptr) { | |
380 sc = SkScaledBitmapSampler::kIndex; | |
381 srcBytesPerPixel = 1; | |
382 } else if (kAlpha_8_SkColorType == colorType) { | |
383 // A8 is only allowed if the original was GRAY. | |
384 SkASSERT(PNG_COLOR_TYPE_GRAY == pngColorType); | |
385 sc = SkScaledBitmapSampler::kGray; | |
386 srcBytesPerPixel = 1; | |
387 } else if (hasAlpha) { | |
388 sc = SkScaledBitmapSampler::kRGBA; | |
389 } else { | |
390 sc = SkScaledBitmapSampler::kRGBX; | |
391 } | |
392 | |
393 /* We have to pass the colortable explicitly, since we may have one | |
394 even if our decodedBitmap doesn't, due to the request that we | |
395 upscale png's palette to a direct model | |
396 */ | |
397 const SkPMColor* colors = colorTable ? colorTable->readColors() : nullpt
r; | |
398 if (!sampler.begin(decodedBitmap, sc, *this, colors)) { | |
399 return kFailure; | |
400 } | |
401 const int height = decodedBitmap->height(); | |
402 | |
403 if (number_passes > 1) { | |
404 SkAutoTMalloc<uint8_t> storage(origWidth * origHeight * srcBytesPerP
ixel); | |
405 uint8_t* base = storage.get(); | |
406 size_t rowBytes = origWidth * srcBytesPerPixel; | |
407 | |
408 for (int i = 0; i < number_passes; i++) { | |
409 uint8_t* row = base; | |
410 for (png_uint_32 y = 0; y < origHeight; y++) { | |
411 uint8_t* bmRow = row; | |
412 png_read_rows(png_ptr, &bmRow, png_bytepp_NULL, 1); | |
413 row += rowBytes; | |
414 } | |
415 } | |
416 // now sample it | |
417 base += sampler.srcY0() * rowBytes; | |
418 for (int y = 0; y < height; y++) { | |
419 reallyHasAlpha |= sampler.next(base); | |
420 base += sampler.srcDY() * rowBytes; | |
421 } | |
422 } else { | |
423 SkAutoTMalloc<uint8_t> storage(origWidth * srcBytesPerPixel); | |
424 uint8_t* srcRow = storage.get(); | |
425 skip_src_rows(png_ptr, srcRow, sampler.srcY0()); | |
426 | |
427 for (int y = 0; y < height; y++) { | |
428 uint8_t* tmp = srcRow; | |
429 png_read_rows(png_ptr, &tmp, png_bytepp_NULL, 1); | |
430 reallyHasAlpha |= sampler.next(srcRow); | |
431 if (y < height - 1) { | |
432 skip_src_rows(png_ptr, srcRow, sampler.srcDY() - 1); | |
433 } | |
434 } | |
435 | |
436 // skip the rest of the rows (if any) | |
437 png_uint_32 read = (height - 1) * sampler.srcDY() + | |
438 sampler.srcY0() + 1; | |
439 SkASSERT(read <= origHeight); | |
440 skip_src_rows(png_ptr, srcRow, origHeight - read); | |
441 } | |
442 } | |
443 | |
444 /* read rest of file, and get additional chunks in info_ptr - REQUIRED */ | |
445 png_read_end(png_ptr, info_ptr); | |
446 | |
447 if (0 != theTranspColor) { | |
448 reallyHasAlpha |= substituteTranspColor(decodedBitmap, theTranspColor); | |
449 } | |
450 if (reallyHasAlpha && this->getRequireUnpremultipliedColors()) { | |
451 switch (decodedBitmap->colorType()) { | |
452 case kIndex_8_SkColorType: | |
453 // Fall through. | |
454 case kARGB_4444_SkColorType: | |
455 // We have chosen not to support unpremul for these colortypes. | |
456 return kFailure; | |
457 default: { | |
458 // Fall through to finish the decode. This colortype either | |
459 // supports unpremul or it is irrelevant because it has no | |
460 // alpha (or only alpha). | |
461 // These brackets prevent a warning. | |
462 } | |
463 } | |
464 } | |
465 | |
466 if (!reallyHasAlpha) { | |
467 decodedBitmap->setAlphaType(kOpaque_SkAlphaType); | |
468 } | |
469 return kSuccess; | |
470 } | |
471 | |
472 | |
473 | |
474 bool SkPNGImageDecoder::getBitmapColorType(png_structp png_ptr, png_infop info_p
tr, | |
475 SkColorType* colorTypep, | |
476 bool* hasAlphap, | |
477 SkPMColor* SK_RESTRICT theTranspColor
p) { | |
478 png_uint_32 origWidth, origHeight; | |
479 int bitDepth, colorType; | |
480 png_get_IHDR(png_ptr, info_ptr, &origWidth, &origHeight, &bitDepth, | |
481 &colorType, int_p_NULL, int_p_NULL, int_p_NULL); | |
482 | |
483 #ifdef PNG_sBIT_SUPPORTED | |
484 // check for sBIT chunk data, in case we should disable dithering because | |
485 // our data is not truely 8bits per component | |
486 png_color_8p sig_bit; | |
487 if (this->getDitherImage() && png_get_sBIT(png_ptr, info_ptr, &sig_bit)) { | |
488 #if 0 | |
489 SkDebugf("----- sBIT %d %d %d %d\n", sig_bit->red, sig_bit->green, | |
490 sig_bit->blue, sig_bit->alpha); | |
491 #endif | |
492 // 0 seems to indicate no information available | |
493 if (pos_le(sig_bit->red, SK_R16_BITS) && | |
494 pos_le(sig_bit->green, SK_G16_BITS) && | |
495 pos_le(sig_bit->blue, SK_B16_BITS)) { | |
496 this->setDitherImage(false); | |
497 } | |
498 } | |
499 #endif | |
500 | |
501 if (colorType == PNG_COLOR_TYPE_PALETTE) { | |
502 bool paletteHasAlpha = hasTransparencyInPalette(png_ptr, info_ptr); | |
503 *colorTypep = this->getPrefColorType(kIndex_SrcDepth, paletteHasAlpha); | |
504 // now see if we can upscale to their requested colortype | |
505 if (!canUpscalePaletteToConfig(*colorTypep, paletteHasAlpha)) { | |
506 *colorTypep = kIndex_8_SkColorType; | |
507 } | |
508 } else { | |
509 png_color_16p transpColor = nullptr; | |
510 int numTransp = 0; | |
511 | |
512 png_get_tRNS(png_ptr, info_ptr, nullptr, &numTransp, &transpColor); | |
513 | |
514 bool valid = png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS); | |
515 | |
516 if (valid && numTransp == 1 && transpColor != nullptr) { | |
517 /* Compute our transparent color, which we'll match against later. | |
518 We don't really handle 16bit components properly here, since we | |
519 do our compare *after* the values have been knocked down to 8bit | |
520 which means we will find more matches than we should. The real | |
521 fix seems to be to see the actual 16bit components, do the | |
522 compare, and then knock it down to 8bits ourselves. | |
523 */ | |
524 if (colorType & PNG_COLOR_MASK_COLOR) { | |
525 if (16 == bitDepth) { | |
526 *theTranspColorp = SkPackARGB32(0xFF, transpColor->red >> 8, | |
527 transpColor->green >> 8, | |
528 transpColor->blue >> 8); | |
529 } else { | |
530 /* We apply the mask because in a very small | |
531 number of corrupt PNGs, (transpColor->red > 255) | |
532 and (bitDepth == 8), for certain versions of libpng. */ | |
533 *theTranspColorp = SkPackARGB32(0xFF, | |
534 0xFF & (transpColor->red), | |
535 0xFF & (transpColor->green), | |
536 0xFF & (transpColor->blue)); | |
537 } | |
538 } else { // gray | |
539 if (16 == bitDepth) { | |
540 *theTranspColorp = SkPackARGB32(0xFF, transpColor->gray >> 8
, | |
541 transpColor->gray >> 8, | |
542 transpColor->gray >> 8); | |
543 } else { | |
544 /* We apply the mask because in a very small | |
545 number of corrupt PNGs, (transpColor->red > | |
546 255) and (bitDepth == 8), for certain versions | |
547 of libpng. For safety we assume the same could | |
548 happen with a grayscale PNG. */ | |
549 *theTranspColorp = SkPackARGB32(0xFF, | |
550 0xFF & (transpColor->gray), | |
551 0xFF & (transpColor->gray), | |
552 0xFF & (transpColor->gray)); | |
553 } | |
554 } | |
555 } | |
556 | |
557 if (valid || | |
558 PNG_COLOR_TYPE_RGB_ALPHA == colorType || | |
559 PNG_COLOR_TYPE_GRAY_ALPHA == colorType) { | |
560 *hasAlphap = true; | |
561 } | |
562 | |
563 SrcDepth srcDepth = k32Bit_SrcDepth; | |
564 if (PNG_COLOR_TYPE_GRAY == colorType) { | |
565 srcDepth = k8BitGray_SrcDepth; | |
566 // Remove this assert, which fails on desk_pokemonwiki.skp | |
567 //SkASSERT(!*hasAlphap); | |
568 } | |
569 | |
570 *colorTypep = this->getPrefColorType(srcDepth, *hasAlphap); | |
571 // now match the request against our capabilities | |
572 if (*hasAlphap) { | |
573 if (*colorTypep != kARGB_4444_SkColorType) { | |
574 *colorTypep = kN32_SkColorType; | |
575 } | |
576 } else { | |
577 if (kAlpha_8_SkColorType == *colorTypep) { | |
578 if (k8BitGray_SrcDepth != srcDepth) { | |
579 // Converting a non grayscale image to A8 is not currently s
upported. | |
580 *colorTypep = kN32_SkColorType; | |
581 } | |
582 } else if (*colorTypep != kRGB_565_SkColorType && | |
583 *colorTypep != kARGB_4444_SkColorType) { | |
584 *colorTypep = kN32_SkColorType; | |
585 } | |
586 } | |
587 } | |
588 | |
589 // sanity check for size | |
590 { | |
591 int64_t size = sk_64_mul(origWidth, origHeight); | |
592 // now check that if we are 4-bytes per pixel, we also don't overflow | |
593 if (size < 0 || size > (0x7FFFFFFF >> 2)) { | |
594 return false; | |
595 } | |
596 } | |
597 | |
598 // If the image has alpha and the decoder wants unpremultiplied | |
599 // colors, the only supported colortype is 8888. | |
600 if (this->getRequireUnpremultipliedColors() && *hasAlphap) { | |
601 *colorTypep = kN32_SkColorType; | |
602 } | |
603 | |
604 if (fImageIndex != nullptr) { | |
605 if (kUnknown_SkColorType == fImageIndex->fColorType) { | |
606 // This is the first time for this subset decode. From now on, | |
607 // all decodes must be in the same colortype. | |
608 fImageIndex->fColorType = *colorTypep; | |
609 } else if (fImageIndex->fColorType != *colorTypep) { | |
610 // Requesting a different colortype for a subsequent decode is not | |
611 // supported. Report failure before we make changes to png_ptr. | |
612 return false; | |
613 } | |
614 } | |
615 | |
616 bool convertGrayToRGB = PNG_COLOR_TYPE_GRAY == colorType && *colorTypep != k
Alpha_8_SkColorType; | |
617 | |
618 // Unless the user is requesting A8, convert a grayscale image into RGB. | |
619 // GRAY_ALPHA will always be converted to RGB | |
620 if (convertGrayToRGB || colorType == PNG_COLOR_TYPE_GRAY_ALPHA) { | |
621 png_set_gray_to_rgb(png_ptr); | |
622 } | |
623 | |
624 // Add filler (or alpha) byte (after each RGB triplet) if necessary. | |
625 if (colorType == PNG_COLOR_TYPE_RGB || convertGrayToRGB) { | |
626 png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER); | |
627 } | |
628 | |
629 return true; | |
630 } | |
631 | |
632 typedef uint32_t (*PackColorProc)(U8CPU a, U8CPU r, U8CPU g, U8CPU b); | |
633 | |
634 bool SkPNGImageDecoder::decodePalette(png_structp png_ptr, png_infop info_ptr, | |
635 int bitDepth, bool *hasAlphap, | |
636 bool *reallyHasAlphap, | |
637 SkColorTable **colorTablep) { | |
638 int numPalette; | |
639 png_colorp palette; | |
640 png_bytep trans; | |
641 int numTrans; | |
642 | |
643 png_get_PLTE(png_ptr, info_ptr, &palette, &numPalette); | |
644 | |
645 SkPMColor colorStorage[256]; // worst-case storage | |
646 SkPMColor* colorPtr = colorStorage; | |
647 | |
648 if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) { | |
649 png_get_tRNS(png_ptr, info_ptr, &trans, &numTrans, nullptr); | |
650 *hasAlphap = (numTrans > 0); | |
651 } else { | |
652 numTrans = 0; | |
653 } | |
654 | |
655 // check for bad images that might make us crash | |
656 if (numTrans > numPalette) { | |
657 numTrans = numPalette; | |
658 } | |
659 | |
660 int index = 0; | |
661 int transLessThanFF = 0; | |
662 | |
663 // Choose which function to use to create the color table. If the final dest
ination's | |
664 // colortype is unpremultiplied, the color table will store unpremultiplied
colors. | |
665 PackColorProc proc; | |
666 if (this->getRequireUnpremultipliedColors()) { | |
667 proc = &SkPackARGB32NoCheck; | |
668 } else { | |
669 proc = &SkPreMultiplyARGB; | |
670 } | |
671 for (; index < numTrans; index++) { | |
672 transLessThanFF |= (int)*trans - 0xFF; | |
673 *colorPtr++ = proc(*trans++, palette->red, palette->green, palette->blue
); | |
674 palette++; | |
675 } | |
676 bool reallyHasAlpha = (transLessThanFF < 0); | |
677 | |
678 for (; index < numPalette; index++) { | |
679 *colorPtr++ = SkPackARGB32(0xFF, palette->red, palette->green, palette->
blue); | |
680 palette++; | |
681 } | |
682 | |
683 /* BUGGY IMAGE WORKAROUND | |
684 | |
685 Invalid images could contain pixel values that are greater than the numb
er of palette | |
686 entries. Since we use pixel values as indices into the palette this coul
d result in reading | |
687 beyond the end of the palette which could leak the contents of uninitial
ized memory. To | |
688 ensure this doesn't happen, we grow the colortable to the maximum size t
hat can be | |
689 addressed by the bitdepth of the image and fill it with the last palette
color or black if | |
690 the palette is empty (really broken image). | |
691 */ | |
692 int colorCount = SkTMax(numPalette, 1 << SkTMin(bitDepth, 8)); | |
693 SkPMColor lastColor = index > 0 ? colorPtr[-1] : SkPackARGB32(0xFF, 0, 0, 0)
; | |
694 for (; index < colorCount; index++) { | |
695 *colorPtr++ = lastColor; | |
696 } | |
697 | |
698 *colorTablep = new SkColorTable(colorStorage, colorCount); | |
699 *reallyHasAlphap = reallyHasAlpha; | |
700 return true; | |
701 } | |
702 | |
703 /////////////////////////////////////////////////////////////////////////////// | |
704 | |
705 #include "SkColorPriv.h" | |
706 #include "SkUnPreMultiply.h" | |
707 | |
708 static void sk_write_fn(png_structp png_ptr, png_bytep data, png_size_t len) { | 57 static void sk_write_fn(png_structp png_ptr, png_bytep data, png_size_t len) { |
709 SkWStream* sk_stream = (SkWStream*)png_get_io_ptr(png_ptr); | 58 SkWStream* sk_stream = (SkWStream*)png_get_io_ptr(png_ptr); |
710 if (!sk_stream->write(data, len)) { | 59 if (!sk_stream->write(data, len)) { |
711 png_error(png_ptr, "sk_write_fn Error!"); | 60 png_error(png_ptr, "sk_write_fn Error!"); |
712 } | 61 } |
713 } | 62 } |
714 | 63 |
715 static transform_scanline_proc choose_proc(SkColorType ct, bool hasAlpha) { | 64 static transform_scanline_proc choose_proc(SkColorType ct, bool hasAlpha) { |
716 // we don't care about search on alpha if we're kIndex8, since only the | 65 // we don't care about search on alpha if we're kIndex8, since only the |
717 // colortable packing cares about that distinction, not the pixels | 66 // colortable packing cares about that distinction, not the pixels |
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978 } | 327 } |
979 | 328 |
980 png_write_end(png_ptr, info_ptr); | 329 png_write_end(png_ptr, info_ptr); |
981 | 330 |
982 /* clean up after the write, and free any memory allocated */ | 331 /* clean up after the write, and free any memory allocated */ |
983 png_destroy_write_struct(&png_ptr, &info_ptr); | 332 png_destroy_write_struct(&png_ptr, &info_ptr); |
984 return true; | 333 return true; |
985 } | 334 } |
986 | 335 |
987 /////////////////////////////////////////////////////////////////////////////// | 336 /////////////////////////////////////////////////////////////////////////////// |
988 DEFINE_DECODER_CREATOR(PNGImageDecoder); | |
989 DEFINE_ENCODER_CREATOR(PNGImageEncoder); | 337 DEFINE_ENCODER_CREATOR(PNGImageEncoder); |
990 /////////////////////////////////////////////////////////////////////////////// | 338 /////////////////////////////////////////////////////////////////////////////// |
991 | 339 |
992 static bool is_png(SkStreamRewindable* stream) { | |
993 char buf[PNG_BYTES_TO_CHECK]; | |
994 if (stream->read(buf, PNG_BYTES_TO_CHECK) == PNG_BYTES_TO_CHECK && | |
995 !png_sig_cmp((png_bytep) buf, (png_size_t)0, PNG_BYTES_TO_CHECK)) { | |
996 return true; | |
997 } | |
998 return false; | |
999 } | |
1000 | |
1001 SkImageDecoder* sk_libpng_dfactory(SkStreamRewindable* stream) { | |
1002 if (is_png(stream)) { | |
1003 return new SkPNGImageDecoder; | |
1004 } | |
1005 return nullptr; | |
1006 } | |
1007 | |
1008 static SkImageDecoder::Format get_format_png(SkStreamRewindable* stream) { | |
1009 if (is_png(stream)) { | |
1010 return SkImageDecoder::kPNG_Format; | |
1011 } | |
1012 return SkImageDecoder::kUnknown_Format; | |
1013 } | |
1014 | |
1015 SkImageEncoder* sk_libpng_efactory(SkImageEncoder::Type t) { | 340 SkImageEncoder* sk_libpng_efactory(SkImageEncoder::Type t) { |
1016 return (SkImageEncoder::kPNG_Type == t) ? new SkPNGImageEncoder : nullptr; | 341 return (SkImageEncoder::kPNG_Type == t) ? new SkPNGImageEncoder : nullptr; |
1017 } | 342 } |
1018 | 343 |
1019 static SkImageDecoder_DecodeReg gDReg(sk_libpng_dfactory); | |
1020 static SkImageDecoder_FormatReg gFormatReg(get_format_png); | |
1021 static SkImageEncoder_EncodeReg gEReg(sk_libpng_efactory); | 344 static SkImageEncoder_EncodeReg gEReg(sk_libpng_efactory); |
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