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1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "ui/gfx/codec/jpeg_codec.h" | 5 #include "ui/gfx/codec/jpeg_codec.h" |
6 | 6 |
7 #include <setjmp.h> | 7 #include <setjmp.h> |
8 | 8 |
9 #include <memory> | 9 #include <memory> |
10 | 10 |
11 #include "base/logging.h" | 11 #include "base/logging.h" |
12 #include "third_party/skia/include/core/SkBitmap.h" | 12 #include "third_party/skia/include/core/SkBitmap.h" |
13 #include "third_party/skia/include/core/SkColorPriv.h" | 13 #include "third_party/skia/include/core/SkColorPriv.h" |
14 #include "third_party/skia/include/core/SkStream.h" | |
15 #include "third_party/skia/include/encode/SkJpegEncoder.h" | |
14 | 16 |
15 extern "C" { | 17 extern "C" { |
16 #if defined(USE_SYSTEM_LIBJPEG) | 18 #if defined(USE_SYSTEM_LIBJPEG) |
17 #include <jpeglib.h> | 19 #include <jpeglib.h> |
18 #elif defined(USE_LIBJPEG_TURBO) | 20 #elif defined(USE_LIBJPEG_TURBO) |
19 #include "third_party/libjpeg_turbo/jpeglib.h" | 21 #include "third_party/libjpeg_turbo/jpeglib.h" |
20 #else | 22 #else |
21 #include "third_party/libjpeg/jpeglib.h" | 23 #include "third_party/libjpeg/jpeglib.h" |
22 #endif | 24 #endif |
23 } | 25 } |
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48 #if defined(USE_SYSTEM_LIBJPEG) | 50 #if defined(USE_SYSTEM_LIBJPEG) |
49 return SYSTEM_LIBJPEG; | 51 return SYSTEM_LIBJPEG; |
50 #elif defined(USE_LIBJPEG_TURBO) | 52 #elif defined(USE_LIBJPEG_TURBO) |
51 return LIBJPEG_TURBO; | 53 return LIBJPEG_TURBO; |
52 #else | 54 #else |
53 return IJG_LIBJPEG; | 55 return IJG_LIBJPEG; |
54 #endif | 56 #endif |
55 } | 57 } |
56 | 58 |
57 // Encoder --------------------------------------------------------------------- | 59 // Encoder --------------------------------------------------------------------- |
58 // | |
59 // This code is based on nsJPEGEncoder from Mozilla. | |
60 // Copyright 2005 Google Inc. (Brett Wilson, contributor) | |
61 | 60 |
62 namespace { | 61 namespace { |
63 | 62 |
64 // Initial size for the output buffer in the JpegEncoderState below. | 63 class VectorWStream : public SkWStream { |
65 static const int initial_output_buffer_size = 8192; | 64 public: |
66 | 65 VectorWStream(std::vector<unsigned char>* dst) : dst_(dst) { |
67 struct JpegEncoderState { | 66 DCHECK(dst_); |
68 explicit JpegEncoderState(std::vector<unsigned char>* o) | 67 DCHECK_EQ(0UL, dst->size()); |
scroggo_chromium
2017/05/30 14:27:52
Not a huge deal, but in the first DCHECK you used
msarett1
2017/06/07 18:01:14
Done.
| |
69 : out(o), | |
70 image_buffer_used(0) { | |
71 } | 68 } |
72 | 69 |
73 // Output buffer, of which 'image_buffer_used' bytes are actually used (this | 70 bool write(const void* buffer, size_t size) override { |
74 // will often be less than the actual size of the vector because we size it | 71 dst_->insert(dst_->end(), reinterpret_cast<const unsigned char*>(buffer), |
scroggo_chromium
2017/05/30 14:27:52
nit: Use a temporary to make this more readable?
msarett1
2017/06/07 18:01:14
Done.
| |
75 // so that libjpeg can write directly into it. | 72 reinterpret_cast<const unsigned char*>(buffer) + size); |
76 std::vector<unsigned char>* out; | 73 return true; |
74 } | |
77 | 75 |
78 // Number of bytes in the 'out' buffer that are actually used (see above). | 76 size_t bytesWritten() const override { return dst_->size(); } |
79 size_t image_buffer_used; | 77 |
78 private: | |
79 // Does not have ownership. | |
80 std::vector<unsigned char>* dst_; | |
81 }; | |
80 }; | 82 }; |
81 | 83 |
82 // Initializes the JpegEncoderState for encoding, and tells libjpeg about where | 84 bool JPEGCodec::Encode(const unsigned char* input, |
83 // the output buffer is. | 85 SkColorType colorType, |
84 // | 86 int w, |
85 // From the JPEG library: | 87 int h, |
86 // "Initialize destination. This is called by jpeg_start_compress() before | 88 int row_byte_width, |
87 // any data is actually written. It must initialize next_output_byte and | 89 int quality, |
88 // free_in_buffer. free_in_buffer must be initialized to a positive value." | 90 std::vector<unsigned char>* output) { |
89 void InitDestination(jpeg_compress_struct* cinfo) { | 91 output->clear(); |
90 JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data); | 92 VectorWStream dst(output); |
91 DCHECK(state->image_buffer_used == 0) << "initializing after use"; | |
92 | 93 |
93 state->out->resize(initial_output_buffer_size); | 94 SkImageInfo info = SkImageInfo::Make(w, h, colorType, kOpaque_SkAlphaType); |
94 state->image_buffer_used = 0; | 95 SkPixmap src(info, input, row_byte_width); |
95 | 96 |
96 cinfo->dest->next_output_byte = &(*state->out)[0]; | 97 SkJpegEncoder::Options options; |
97 cinfo->dest->free_in_buffer = initial_output_buffer_size; | 98 options.fQuality = quality; |
98 } | |
99 | 99 |
100 // Resize the buffer that we give to libjpeg and update our and its state. | 100 return SkJpegEncoder::Encode(&dst, src, options); |
101 // | |
102 // From the JPEG library: | |
103 // "Callback used by libjpeg whenever the buffer has filled (free_in_buffer | |
104 // reaches zero). In typical applications, it should write out the *entire* | |
105 // buffer (use the saved start address and buffer length; ignore the current | |
106 // state of next_output_byte and free_in_buffer). Then reset the pointer & | |
107 // count to the start of the buffer, and return TRUE indicating that the | |
108 // buffer has been dumped. free_in_buffer must be set to a positive value | |
109 // when TRUE is returned. A FALSE return should only be used when I/O | |
110 // suspension is desired (this operating mode is discussed in the next | |
111 // section)." | |
112 boolean EmptyOutputBuffer(jpeg_compress_struct* cinfo) { | |
113 JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data); | |
114 | |
115 // note the new size, the buffer is full | |
116 state->image_buffer_used = state->out->size(); | |
117 | |
118 // expand buffer, just double size each time | |
119 state->out->resize(state->out->size() * 2); | |
120 | |
121 // tell libjpeg where to write the next data | |
122 cinfo->dest->next_output_byte = &(*state->out)[state->image_buffer_used]; | |
123 cinfo->dest->free_in_buffer = state->out->size() - state->image_buffer_used; | |
124 return 1; | |
125 } | |
126 | |
127 // Cleans up the JpegEncoderState to prepare for returning in the final form. | |
128 // | |
129 // From the JPEG library: | |
130 // "Terminate destination --- called by jpeg_finish_compress() after all data | |
131 // has been written. In most applications, this must flush any data | |
132 // remaining in the buffer. Use either next_output_byte or free_in_buffer to | |
133 // determine how much data is in the buffer." | |
134 void TermDestination(jpeg_compress_struct* cinfo) { | |
135 JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data); | |
136 DCHECK(state->out->size() >= state->image_buffer_used); | |
137 | |
138 // update the used byte based on the next byte libjpeg would write to | |
139 state->image_buffer_used = cinfo->dest->next_output_byte - &(*state->out)[0]; | |
140 DCHECK(state->image_buffer_used < state->out->size()) << | |
141 "JPEG library busted, got a bad image buffer size"; | |
142 | |
143 // update our buffer so that it exactly encompases the desired data | |
144 state->out->resize(state->image_buffer_used); | |
145 } | |
146 | |
147 #if !defined(JCS_EXTENSIONS) | |
148 // Converts RGBA to RGB (removing the alpha values) to prepare to send data to | |
149 // libjpeg. This converts one row of data in rgba with the given width in | |
150 // pixels the the given rgb destination buffer (which should have enough space | |
151 // reserved for the final data). | |
152 void StripAlpha(const unsigned char* rgba, int pixel_width, unsigned char* rgb) | |
153 { | |
154 for (int x = 0; x < pixel_width; x++) | |
155 memcpy(&rgb[x * 3], &rgba[x * 4], 3); | |
156 } | |
157 | |
158 // Converts BGRA to RGB by reordering the color components and dropping the | |
159 // alpha. This converts one row of data in rgba with the given width in | |
160 // pixels the the given rgb destination buffer (which should have enough space | |
161 // reserved for the final data). | |
162 void BGRAtoRGB(const unsigned char* bgra, int pixel_width, unsigned char* rgb) | |
163 { | |
164 for (int x = 0; x < pixel_width; x++) { | |
165 const unsigned char* pixel_in = &bgra[x * 4]; | |
166 unsigned char* pixel_out = &rgb[x * 3]; | |
167 pixel_out[0] = pixel_in[2]; | |
168 pixel_out[1] = pixel_in[1]; | |
169 pixel_out[2] = pixel_in[0]; | |
170 } | |
171 } | |
172 #endif // !defined(JCS_EXTENSIONS) | |
173 | |
174 // This class destroys the given jpeg_compress object when it goes out of | |
175 // scope. It simplifies the error handling in Encode (and even applies to the | |
176 // success case). | |
177 class CompressDestroyer { | |
178 public: | |
179 CompressDestroyer() : cinfo_(NULL) { | |
180 } | |
181 ~CompressDestroyer() { | |
182 DestroyManagedObject(); | |
183 } | |
184 void SetManagedObject(jpeg_compress_struct* ci) { | |
185 DestroyManagedObject(); | |
186 cinfo_ = ci; | |
187 } | |
188 void DestroyManagedObject() { | |
189 if (cinfo_) { | |
190 jpeg_destroy_compress(cinfo_); | |
191 cinfo_ = NULL; | |
192 } | |
193 } | |
194 private: | |
195 jpeg_compress_struct* cinfo_; | |
196 }; | |
197 | |
198 } // namespace | |
199 | |
200 bool JPEGCodec::Encode(const unsigned char* input, ColorFormat format, | |
201 int w, int h, int row_byte_width, | |
202 int quality, std::vector<unsigned char>* output) { | |
203 jpeg_compress_struct cinfo; | |
204 CompressDestroyer destroyer; | |
205 destroyer.SetManagedObject(&cinfo); | |
206 output->clear(); | |
207 #if !defined(JCS_EXTENSIONS) | |
208 unsigned char* row_buffer = NULL; | |
209 #endif | |
210 | |
211 // We set up the normal JPEG error routines, then override error_exit. | |
212 // This must be done before the call to create_compress. | |
213 CoderErrorMgr errmgr; | |
214 cinfo.err = jpeg_std_error(&errmgr.pub); | |
215 errmgr.pub.error_exit = ErrorExit; | |
216 | |
217 // Establish the setjmp return context for ErrorExit to use. | |
218 if (setjmp(errmgr.setjmp_buffer)) { | |
219 // If we get here, the JPEG code has signaled an error. | |
220 // MSDN notes: "if you intend your code to be portable, do not rely on | |
221 // correct destruction of frame-based objects when executing a nonlocal | |
222 // goto using a call to longjmp." So we delete the CompressDestroyer's | |
223 // object manually instead. | |
224 destroyer.DestroyManagedObject(); | |
225 #if !defined(JCS_EXTENSIONS) | |
226 delete[] row_buffer; | |
227 #endif | |
228 return false; | |
229 } | |
230 | |
231 // The destroyer will destroy() cinfo on exit. | |
232 jpeg_create_compress(&cinfo); | |
233 | |
234 cinfo.image_width = w; | |
235 cinfo.image_height = h; | |
236 cinfo.input_components = 3; | |
237 #ifdef JCS_EXTENSIONS | |
238 // Choose an input colorspace and return if it is an unsupported one. Since | |
239 // libjpeg-turbo supports all input formats used by Chromium (i.e. RGB, RGBA, | |
240 // and BGRA), we just map the input parameters to a colorspace used by | |
241 // libjpeg-turbo. | |
242 if (format == FORMAT_RGB) { | |
243 cinfo.input_components = 3; | |
244 cinfo.in_color_space = JCS_RGB; | |
245 } else if (format == FORMAT_RGBA || | |
246 (format == FORMAT_SkBitmap && SK_R32_SHIFT == 0)) { | |
247 cinfo.input_components = 4; | |
248 cinfo.in_color_space = JCS_EXT_RGBX; | |
249 } else if (format == FORMAT_BGRA || | |
250 (format == FORMAT_SkBitmap && SK_B32_SHIFT == 0)) { | |
251 cinfo.input_components = 4; | |
252 cinfo.in_color_space = JCS_EXT_BGRX; | |
253 } else { | |
254 // We can exit this function without calling jpeg_destroy_compress() because | |
255 // CompressDestroyer automaticaly calls it. | |
256 NOTREACHED() << "Invalid pixel format"; | |
257 return false; | |
258 } | |
259 #else | |
260 cinfo.in_color_space = JCS_RGB; | |
261 #endif | |
262 cinfo.data_precision = 8; | |
263 | |
264 jpeg_set_defaults(&cinfo); | |
265 jpeg_set_quality(&cinfo, quality, 1); // quality here is 0-100 | |
266 | |
267 // set up the destination manager | |
268 jpeg_destination_mgr destmgr; | |
269 destmgr.init_destination = InitDestination; | |
270 destmgr.empty_output_buffer = EmptyOutputBuffer; | |
271 destmgr.term_destination = TermDestination; | |
272 cinfo.dest = &destmgr; | |
273 | |
274 JpegEncoderState state(output); | |
275 cinfo.client_data = &state; | |
276 | |
277 jpeg_start_compress(&cinfo, 1); | |
278 | |
279 // feed it the rows, doing necessary conversions for the color format | |
280 #ifdef JCS_EXTENSIONS | |
281 // This function already returns when the input format is not supported by | |
282 // libjpeg-turbo and needs conversion. Therefore, we just encode lines without | |
283 // conversions. | |
284 while (cinfo.next_scanline < cinfo.image_height) { | |
285 const unsigned char* row = &input[cinfo.next_scanline * row_byte_width]; | |
286 jpeg_write_scanlines(&cinfo, const_cast<unsigned char**>(&row), 1); | |
287 } | |
288 #else | |
289 if (format == FORMAT_RGB) { | |
290 // no conversion necessary | |
291 while (cinfo.next_scanline < cinfo.image_height) { | |
292 const unsigned char* row = &input[cinfo.next_scanline * row_byte_width]; | |
293 jpeg_write_scanlines(&cinfo, const_cast<unsigned char**>(&row), 1); | |
294 } | |
295 } else { | |
296 // get the correct format converter | |
297 void (*converter)(const unsigned char* in, int w, unsigned char* rgb); | |
298 if (format == FORMAT_RGBA || | |
299 (format == FORMAT_SkBitmap && SK_R32_SHIFT == 0)) { | |
300 converter = StripAlpha; | |
301 } else if (format == FORMAT_BGRA || | |
302 (format == FORMAT_SkBitmap && SK_B32_SHIFT == 0)) { | |
303 converter = BGRAtoRGB; | |
304 } else { | |
305 NOTREACHED() << "Invalid pixel format"; | |
306 return false; | |
307 } | |
308 | |
309 // output row after converting | |
310 row_buffer = new unsigned char[w * 3]; | |
311 | |
312 while (cinfo.next_scanline < cinfo.image_height) { | |
313 converter(&input[cinfo.next_scanline * row_byte_width], w, row_buffer); | |
314 jpeg_write_scanlines(&cinfo, &row_buffer, 1); | |
315 } | |
316 delete[] row_buffer; | |
317 } | |
318 #endif | |
319 | |
320 jpeg_finish_compress(&cinfo); | |
321 return true; | |
322 } | 101 } |
323 | 102 |
324 // Decoder -------------------------------------------------------------------- | 103 // Decoder -------------------------------------------------------------------- |
325 | 104 |
326 namespace { | 105 namespace { |
327 | 106 |
328 struct JpegDecoderState { | 107 struct JpegDecoderState { |
329 JpegDecoderState(const unsigned char* in, size_t len) | 108 JpegDecoderState(const unsigned char* in, size_t len) |
330 : input_buffer(in), input_buffer_length(len) { | 109 : input_buffer(in), input_buffer_length(len) { |
331 } | 110 } |
(...skipping 160 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
492 return false; | 271 return false; |
493 | 272 |
494 // we want to always get RGB data out | 273 // we want to always get RGB data out |
495 switch (cinfo.jpeg_color_space) { | 274 switch (cinfo.jpeg_color_space) { |
496 case JCS_GRAYSCALE: | 275 case JCS_GRAYSCALE: |
497 case JCS_RGB: | 276 case JCS_RGB: |
498 case JCS_YCbCr: | 277 case JCS_YCbCr: |
499 #ifdef JCS_EXTENSIONS | 278 #ifdef JCS_EXTENSIONS |
500 // Choose an output colorspace and return if it is an unsupported one. | 279 // Choose an output colorspace and return if it is an unsupported one. |
501 // Same as JPEGCodec::Encode(), libjpeg-turbo supports all input formats | 280 // Same as JPEGCodec::Encode(), libjpeg-turbo supports all input formats |
502 // used by Chromium (i.e. RGB, RGBA, and BGRA) and we just map the input | 281 // used by Chromium (i.e. RGBA and BGRA) and we just map the input |
503 // parameters to a colorspace. | 282 // parameters to a colorspace. |
504 if (format == FORMAT_RGB) { | 283 if (format == FORMAT_RGBA || |
505 cinfo.out_color_space = JCS_RGB; | 284 (format == FORMAT_SkBitmap && SK_R32_SHIFT == 0)) { |
506 cinfo.output_components = 3; | |
507 } else if (format == FORMAT_RGBA || | |
508 (format == FORMAT_SkBitmap && SK_R32_SHIFT == 0)) { | |
509 cinfo.out_color_space = JCS_EXT_RGBX; | 285 cinfo.out_color_space = JCS_EXT_RGBX; |
510 cinfo.output_components = 4; | 286 cinfo.output_components = 4; |
511 } else if (format == FORMAT_BGRA || | 287 } else if (format == FORMAT_BGRA || |
512 (format == FORMAT_SkBitmap && SK_B32_SHIFT == 0)) { | 288 (format == FORMAT_SkBitmap && SK_B32_SHIFT == 0)) { |
513 cinfo.out_color_space = JCS_EXT_BGRX; | 289 cinfo.out_color_space = JCS_EXT_BGRX; |
514 cinfo.output_components = 4; | 290 cinfo.output_components = 4; |
scroggo_chromium
2017/05/30 14:27:52
It looks like this is always 4 if JCS_EXTENSIONS i
msarett1
2017/06/07 18:01:14
Acknowledged.
| |
515 } else { | 291 } else { |
516 // We can exit this function without calling jpeg_destroy_decompress() | 292 // We can exit this function without calling jpeg_destroy_decompress() |
517 // because DecompressDestroyer automaticaly calls it. | 293 // because DecompressDestroyer automaticaly calls it. |
518 NOTREACHED() << "Invalid pixel format"; | 294 NOTREACHED() << "Invalid pixel format"; |
519 return false; | 295 return false; |
520 } | 296 } |
521 #else | 297 #else |
522 cinfo.out_color_space = JCS_RGB; | 298 cinfo.out_color_space = JCS_RGB; |
523 #endif | 299 #endif |
524 break; | 300 break; |
(...skipping 24 matching lines...) Expand all Loading... | |
549 // without conversions same as JPEGCodec::Encode(). | 325 // without conversions same as JPEGCodec::Encode(). |
550 int row_write_stride = row_read_stride; | 326 int row_write_stride = row_read_stride; |
551 output->resize(row_write_stride * cinfo.output_height); | 327 output->resize(row_write_stride * cinfo.output_height); |
552 | 328 |
553 for (int row = 0; row < static_cast<int>(cinfo.output_height); row++) { | 329 for (int row = 0; row < static_cast<int>(cinfo.output_height); row++) { |
554 unsigned char* rowptr = &(*output)[row * row_write_stride]; | 330 unsigned char* rowptr = &(*output)[row * row_write_stride]; |
555 if (!jpeg_read_scanlines(&cinfo, &rowptr, 1)) | 331 if (!jpeg_read_scanlines(&cinfo, &rowptr, 1)) |
556 return false; | 332 return false; |
557 } | 333 } |
558 #else | 334 #else |
559 if (format == FORMAT_RGB) { | 335 // Rows need conversion to output format: read into a temporary buffer and |
scroggo_chromium
2017/05/30 14:27:52
So this CL also removes the ability to decode to R
msarett1
2017/06/07 18:01:14
Acknowledged. Removed in a previous CL.
|
scroggo_chromium
2017/05/30 14:27:52
The diff doesn't clearly show this, but I think th
msarett1
2017/06/07 18:01:14
Yes. Should be clearer now.
|
560 // easy case, row needs no conversion | 336 // expand to the final one. Performance: we could avoid the extra |
561 int row_write_stride = row_read_stride; | 337 // allocation by doing the expansion in-place. |
562 output->resize(row_write_stride * cinfo.output_height); | 338 int row_write_stride; |
339 void (*converter)(const unsigned char* rgb, int w, unsigned char* out); | |
340 if (format == FORMAT_RGBA || | |
341 (format == FORMAT_SkBitmap && SK_R32_SHIFT == 0)) { | |
342 row_write_stride = cinfo.output_width * 4; | |
343 converter = AddAlpha; | |
344 } else if (format == FORMAT_BGRA || | |
345 (format == FORMAT_SkBitmap && SK_B32_SHIFT == 0)) { | |
346 row_write_stride = cinfo.output_width * 4; | |
347 converter = RGBtoBGRA; | |
348 } else { | |
349 NOTREACHED() << "Invalid pixel format"; | |
350 jpeg_destroy_decompress(&cinfo); | |
351 return false; | |
352 } | |
563 | 353 |
564 for (int row = 0; row < static_cast<int>(cinfo.output_height); row++) { | 354 output->resize(row_write_stride * cinfo.output_height); |
565 unsigned char* rowptr = &(*output)[row * row_write_stride]; | 355 |
566 if (!jpeg_read_scanlines(&cinfo, &rowptr, 1)) | 356 std::unique_ptr<unsigned char[]> row_data(new unsigned char[row_read_stride]); |
567 return false; | 357 unsigned char* rowptr = row_data.get(); |
568 } | 358 for (int row = 0; row < static_cast<int>(cinfo.output_height); row++) { |
569 } else { | 359 if (!jpeg_read_scanlines(&cinfo, &rowptr, 1)) |
570 // Rows need conversion to output format: read into a temporary buffer and | |
571 // expand to the final one. Performance: we could avoid the extra | |
572 // allocation by doing the expansion in-place. | |
573 int row_write_stride; | |
574 void (*converter)(const unsigned char* rgb, int w, unsigned char* out); | |
575 if (format == FORMAT_RGBA || | |
576 (format == FORMAT_SkBitmap && SK_R32_SHIFT == 0)) { | |
577 row_write_stride = cinfo.output_width * 4; | |
578 converter = AddAlpha; | |
579 } else if (format == FORMAT_BGRA || | |
580 (format == FORMAT_SkBitmap && SK_B32_SHIFT == 0)) { | |
581 row_write_stride = cinfo.output_width * 4; | |
582 converter = RGBtoBGRA; | |
583 } else { | |
584 NOTREACHED() << "Invalid pixel format"; | |
585 jpeg_destroy_decompress(&cinfo); | |
586 return false; | 360 return false; |
587 } | 361 converter(rowptr, *w, &(*output)[row * row_write_stride]); |
588 | |
589 output->resize(row_write_stride * cinfo.output_height); | |
590 | |
591 std::unique_ptr<unsigned char[]> row_data( | |
592 new unsigned char[row_read_stride]); | |
593 unsigned char* rowptr = row_data.get(); | |
594 for (int row = 0; row < static_cast<int>(cinfo.output_height); row++) { | |
595 if (!jpeg_read_scanlines(&cinfo, &rowptr, 1)) | |
596 return false; | |
597 converter(rowptr, *w, &(*output)[row * row_write_stride]); | |
598 } | |
599 } | 362 } |
600 #endif | 363 #endif |
601 | 364 |
602 jpeg_finish_decompress(&cinfo); | 365 jpeg_finish_decompress(&cinfo); |
603 jpeg_destroy_decompress(&cinfo); | 366 jpeg_destroy_decompress(&cinfo); |
604 return true; | 367 return true; |
605 } | 368 } |
606 | 369 |
607 // static | 370 // static |
608 std::unique_ptr<SkBitmap> JPEGCodec::Decode(const unsigned char* input, | 371 std::unique_ptr<SkBitmap> JPEGCodec::Decode(const unsigned char* input, |
609 size_t input_size) { | 372 size_t input_size) { |
610 int w, h; | 373 int w, h; |
611 std::vector<unsigned char> data_vector; | 374 std::vector<unsigned char> data_vector; |
612 if (!Decode(input, input_size, FORMAT_SkBitmap, &data_vector, &w, &h)) | 375 if (!Decode(input, input_size, FORMAT_SkBitmap, &data_vector, &w, &h)) |
613 return nullptr; | 376 return nullptr; |
614 | 377 |
615 // Skia only handles 32 bit images. | 378 // Skia only handles 32 bit images. |
616 int data_length = w * h * 4; | 379 int data_length = w * h * 4; |
617 | 380 |
618 std::unique_ptr<SkBitmap> bitmap(new SkBitmap()); | 381 std::unique_ptr<SkBitmap> bitmap(new SkBitmap()); |
619 bitmap->allocN32Pixels(w, h); | 382 bitmap->allocN32Pixels(w, h); |
620 memcpy(bitmap->getAddr32(0, 0), &data_vector[0], data_length); | 383 memcpy(bitmap->getAddr32(0, 0), &data_vector[0], data_length); |
621 | 384 |
622 return bitmap; | 385 return bitmap; |
623 } | 386 } |
624 | 387 |
625 } // namespace gfx | 388 } // namespace gfx |
OLD | NEW |