reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2007, The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include "SkImageDecoder.h" |
| 18 | #include "SkColorPriv.h" |
| 19 | #include "SkDither.h" |
| 20 | #include "SkScaledBitmapSampler.h" |
| 21 | #include "SkStream.h" |
| 22 | #include "SkTemplates.h" |
| 23 | #include "SkUtils.h" |
| 24 | |
| 25 | #include <stdio.h> |
| 26 | extern "C" { |
| 27 | #include "jpeglib.h" |
| 28 | #include "jerror.h" |
| 29 | } |
| 30 | |
| 31 | // this enables timing code to report milliseconds for an encode |
| 32 | //#define TIME_ENCODE |
| 33 | //#define TIME_DECODE |
| 34 | |
| 35 | // this enables our rgb->yuv code, which is faster than libjpeg on ARM |
| 36 | // disable for the moment, as we have some glitches when width != multiple of 4 |
| 37 | #define WE_CONVERT_TO_YUV |
| 38 | |
| 39 | ////////////////////////////////////////////////////////////////////////// |
| 40 | ////////////////////////////////////////////////////////////////////////// |
| 41 | |
| 42 | class SkJPEGImageDecoder : public SkImageDecoder { |
| 43 | public: |
| 44 | virtual Format getFormat() const { |
| 45 | return kJPEG_Format; |
| 46 | } |
| 47 | |
| 48 | protected: |
| 49 | virtual bool onDecode(SkStream* stream, SkBitmap* bm, |
| 50 | SkBitmap::Config pref, Mode); |
| 51 | }; |
| 52 | |
| 53 | SkImageDecoder* SkImageDecoder_JPEG_Factory(SkStream* stream) { |
| 54 | static const char gHeader[] = { 0xFF, 0xD8, 0xFF }; |
| 55 | static const size_t HEADER_SIZE = sizeof(gHeader); |
| 56 | |
| 57 | char buffer[HEADER_SIZE]; |
| 58 | size_t len = stream->read(buffer, HEADER_SIZE); |
| 59 | |
| 60 | if (len != HEADER_SIZE) { |
| 61 | return NULL; // can't read enough |
| 62 | } |
| 63 | |
| 64 | if (memcmp(buffer, gHeader, HEADER_SIZE)) { |
| 65 | return NULL; |
| 66 | } |
| 67 | |
| 68 | return SkNEW(SkJPEGImageDecoder); |
| 69 | } |
| 70 | |
| 71 | ////////////////////////////////////////////////////////////////////////// |
| 72 | |
| 73 | #include "SkTime.h" |
| 74 | |
| 75 | class AutoTimeMillis { |
| 76 | public: |
| 77 | AutoTimeMillis(const char label[]) : fLabel(label) { |
| 78 | if (!fLabel) { |
| 79 | fLabel = ""; |
| 80 | } |
| 81 | fNow = SkTime::GetMSecs(); |
| 82 | } |
| 83 | ~AutoTimeMillis() { |
| 84 | SkDebugf("---- Time (ms): %s %d\n", fLabel, SkTime::GetMSecs() - fNow); |
| 85 | } |
| 86 | private: |
| 87 | const char* fLabel; |
| 88 | SkMSec fNow; |
| 89 | }; |
| 90 | |
| 91 | /* our source struct for directing jpeg to our stream object |
| 92 | */ |
| 93 | struct sk_source_mgr : jpeg_source_mgr { |
| 94 | sk_source_mgr(SkStream* stream, SkImageDecoder* decoder); |
| 95 | |
| 96 | SkStream* fStream; |
| 97 | const void* fMemoryBase; |
| 98 | size_t fMemoryBaseSize; |
| 99 | SkImageDecoder* fDecoder; |
| 100 | enum { |
| 101 | kBufferSize = 1024 |
| 102 | }; |
| 103 | char fBuffer[kBufferSize]; |
| 104 | }; |
| 105 | |
| 106 | /* Automatically clean up after throwing an exception */ |
| 107 | class JPEGAutoClean { |
| 108 | public: |
| 109 | JPEGAutoClean(): cinfo_ptr(NULL) {} |
| 110 | ~JPEGAutoClean() { |
| 111 | if (cinfo_ptr) { |
| 112 | jpeg_destroy_decompress(cinfo_ptr); |
| 113 | } |
| 114 | } |
| 115 | void set(jpeg_decompress_struct* info) { |
| 116 | cinfo_ptr = info; |
| 117 | } |
| 118 | private: |
| 119 | jpeg_decompress_struct* cinfo_ptr; |
| 120 | }; |
| 121 | |
| 122 | static void sk_init_source(j_decompress_ptr cinfo) { |
| 123 | sk_source_mgr* src = (sk_source_mgr*)cinfo->src; |
| 124 | src->next_input_byte = (const JOCTET*)src->fBuffer; |
| 125 | src->bytes_in_buffer = 0; |
| 126 | } |
| 127 | |
| 128 | static boolean sk_fill_input_buffer(j_decompress_ptr cinfo) { |
| 129 | sk_source_mgr* src = (sk_source_mgr*)cinfo->src; |
| 130 | if (src->fDecoder != NULL && src->fDecoder->shouldCancelDecode()) { |
| 131 | return FALSE; |
| 132 | } |
| 133 | size_t bytes = src->fStream->read(src->fBuffer, sk_source_mgr::kBufferSize); |
| 134 | // note that JPEG is happy with less than the full read, |
| 135 | // as long as the result is non-zero |
| 136 | if (bytes == 0) { |
| 137 | return FALSE; |
| 138 | } |
| 139 | |
| 140 | src->next_input_byte = (const JOCTET*)src->fBuffer; |
| 141 | src->bytes_in_buffer = bytes; |
| 142 | return TRUE; |
| 143 | } |
| 144 | |
| 145 | static void sk_skip_input_data(j_decompress_ptr cinfo, long num_bytes) { |
| 146 | SkASSERT(num_bytes > 0); |
| 147 | |
| 148 | sk_source_mgr* src = (sk_source_mgr*)cinfo->src; |
| 149 | |
| 150 | long bytesToSkip = num_bytes - src->bytes_in_buffer; |
| 151 | |
| 152 | // check if the skip amount exceeds the current buffer |
| 153 | if (bytesToSkip > 0) { |
| 154 | size_t bytes = src->fStream->skip(bytesToSkip); |
| 155 | if (bytes != (size_t)bytesToSkip) { |
| 156 | // SkDebugf("xxxxxxxxxxxxxx failure to skip request %d actual %d\n", bytesToSkip, bytes); |
| 157 | cinfo->err->error_exit((j_common_ptr)cinfo); |
| 158 | } |
| 159 | src->next_input_byte = (const JOCTET*)src->fBuffer; |
| 160 | src->bytes_in_buffer = 0; |
| 161 | } else { |
| 162 | src->next_input_byte += num_bytes; |
| 163 | src->bytes_in_buffer -= num_bytes; |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | static boolean sk_resync_to_restart(j_decompress_ptr cinfo, int desired) { |
| 168 | sk_source_mgr* src = (sk_source_mgr*)cinfo->src; |
| 169 | |
| 170 | // what is the desired param for??? |
| 171 | |
| 172 | if (!src->fStream->rewind()) { |
| 173 | SkDebugf("xxxxxxxxxxxxxx failure to rewind\n"); |
| 174 | cinfo->err->error_exit((j_common_ptr)cinfo); |
| 175 | return FALSE; |
| 176 | } |
| 177 | src->next_input_byte = (const JOCTET*)src->fBuffer; |
| 178 | src->bytes_in_buffer = 0; |
| 179 | return TRUE; |
| 180 | } |
| 181 | |
| 182 | static void sk_term_source(j_decompress_ptr /*cinfo*/) {} |
| 183 | |
| 184 | /////////////////////////////////////////////////////////////////////////////// |
| 185 | |
| 186 | static void skmem_init_source(j_decompress_ptr cinfo) { |
| 187 | sk_source_mgr* src = (sk_source_mgr*)cinfo->src; |
| 188 | src->next_input_byte = (const JOCTET*)src->fMemoryBase; |
| 189 | src->bytes_in_buffer = src->fMemoryBaseSize; |
| 190 | } |
| 191 | |
| 192 | static boolean skmem_fill_input_buffer(j_decompress_ptr cinfo) { |
| 193 | SkDebugf("xxxxxxxxxxxxxx skmem_fill_input_buffer called\n"); |
| 194 | return FALSE; |
| 195 | } |
| 196 | |
| 197 | static void skmem_skip_input_data(j_decompress_ptr cinfo, long num_bytes) { |
| 198 | sk_source_mgr* src = (sk_source_mgr*)cinfo->src; |
| 199 | // SkDebugf("xxxxxxxxxxxxxx skmem_skip_input_data called %d\n", num_bytes); |
| 200 | src->next_input_byte = (const JOCTET*)((const char*)src->next_input_byte + num_bytes); |
| 201 | src->bytes_in_buffer -= num_bytes; |
| 202 | } |
| 203 | |
| 204 | static boolean skmem_resync_to_restart(j_decompress_ptr cinfo, int desired) { |
| 205 | SkDebugf("xxxxxxxxxxxxxx skmem_resync_to_restart called\n"); |
| 206 | return TRUE; |
| 207 | } |
| 208 | |
| 209 | static void skmem_term_source(j_decompress_ptr /*cinfo*/) {} |
| 210 | |
| 211 | /////////////////////////////////////////////////////////////////////////////// |
| 212 | |
| 213 | sk_source_mgr::sk_source_mgr(SkStream* stream, SkImageDecoder* decoder) : fStream(stream) { |
| 214 | fDecoder = decoder; |
| 215 | const void* baseAddr = stream->getMemoryBase(); |
| 216 | if (baseAddr && false) { |
| 217 | fMemoryBase = baseAddr; |
| 218 | fMemoryBaseSize = stream->getLength(); |
| 219 | |
| 220 | init_source = skmem_init_source; |
| 221 | fill_input_buffer = skmem_fill_input_buffer; |
| 222 | skip_input_data = skmem_skip_input_data; |
| 223 | resync_to_restart = skmem_resync_to_restart; |
| 224 | term_source = skmem_term_source; |
| 225 | } else { |
| 226 | fMemoryBase = NULL; |
| 227 | fMemoryBaseSize = 0; |
| 228 | |
| 229 | init_source = sk_init_source; |
| 230 | fill_input_buffer = sk_fill_input_buffer; |
| 231 | skip_input_data = sk_skip_input_data; |
| 232 | resync_to_restart = sk_resync_to_restart; |
| 233 | term_source = sk_term_source; |
| 234 | } |
| 235 | // SkDebugf("**************** use memorybase %p %d\n", fMemoryBase, fMemoryBaseSize); |
| 236 | } |
| 237 | |
| 238 | #include <setjmp.h> |
| 239 | |
| 240 | struct sk_error_mgr : jpeg_error_mgr { |
| 241 | jmp_buf fJmpBuf; |
| 242 | }; |
| 243 | |
| 244 | static void sk_error_exit(j_common_ptr cinfo) { |
| 245 | sk_error_mgr* error = (sk_error_mgr*)cinfo->err; |
| 246 | |
| 247 | (*error->output_message) (cinfo); |
| 248 | |
| 249 | /* Let the memory manager delete any temp files before we die */ |
| 250 | jpeg_destroy(cinfo); |
| 251 | |
| 252 | longjmp(error->fJmpBuf, -1); |
| 253 | } |
| 254 | |
| 255 | /////////////////////////////////////////////////////////////////////////////// |
| 256 | |
| 257 | static bool skip_src_rows(jpeg_decompress_struct* cinfo, void* buffer, |
| 258 | int count) { |
| 259 | for (int i = 0; i < count; i++) { |
| 260 | JSAMPLE* rowptr = (JSAMPLE*)buffer; |
| 261 | int row_count = jpeg_read_scanlines(cinfo, &rowptr, 1); |
| 262 | if (row_count != 1) { |
| 263 | return false; |
| 264 | } |
| 265 | } |
| 266 | return true; |
| 267 | } |
| 268 | |
| 269 | // This guy exists just to aid in debugging, as it allows debuggers to just |
| 270 | // set a break-point in one place to see all error exists. |
| 271 | static bool return_false(const jpeg_decompress_struct& cinfo, |
| 272 | const SkBitmap& bm, const char msg[]) { |
| 273 | #if 0 |
| 274 | SkDebugf("libjpeg error %d <%s> from %s [%d %d]", cinfo.err->msg_code, |
| 275 | cinfo.err->jpeg_message_table[cinfo.err->msg_code], msg, |
| 276 | bm.width(), bm.height()); |
| 277 | #endif |
| 278 | return false; // must always return false |
| 279 | } |
| 280 | |
| 281 | bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, |
| 282 | SkBitmap::Config prefConfig, Mode mode) { |
| 283 | #ifdef TIME_DECODE |
| 284 | AutoTimeMillis atm("JPEG Decode"); |
| 285 | #endif |
| 286 | |
| 287 | SkAutoMalloc srcStorage; |
| 288 | JPEGAutoClean autoClean; |
| 289 | |
| 290 | jpeg_decompress_struct cinfo; |
| 291 | sk_error_mgr sk_err; |
| 292 | sk_source_mgr sk_stream(stream, this); |
| 293 | |
| 294 | cinfo.err = jpeg_std_error(&sk_err); |
| 295 | sk_err.error_exit = sk_error_exit; |
| 296 | |
| 297 | // All objects need to be instantiated before this setjmp call so that |
| 298 | // they will be cleaned up properly if an error occurs. |
| 299 | if (setjmp(sk_err.fJmpBuf)) { |
| 300 | return return_false(cinfo, *bm, "setjmp"); |
| 301 | } |
| 302 | |
| 303 | jpeg_create_decompress(&cinfo); |
| 304 | autoClean.set(&cinfo); |
| 305 | |
| 306 | //jpeg_stdio_src(&cinfo, file); |
| 307 | cinfo.src = &sk_stream; |
| 308 | |
| 309 | int status = jpeg_read_header(&cinfo, true); |
| 310 | if (status != JPEG_HEADER_OK) { |
| 311 | return return_false(cinfo, *bm, "read_header"); |
| 312 | } |
| 313 | |
| 314 | /* Try to fulfill the requested sampleSize. Since jpeg can do it (when it |
| 315 | can) much faster that we, just use their num/denom api to approximate |
| 316 | the size. |
| 317 | */ |
| 318 | int sampleSize = this->getSampleSize(); |
| 319 | |
| 320 | cinfo.dct_method = JDCT_IFAST; |
| 321 | cinfo.scale_num = 1; |
| 322 | cinfo.scale_denom = sampleSize; |
| 323 | |
| 324 | /* this gives about 30% performance improvement. In theory it may |
| 325 | reduce the visual quality, in practice I'm not seeing a difference |
| 326 | */ |
| 327 | cinfo.do_fancy_upsampling = 0; |
| 328 | |
| 329 | /* this gives another few percents */ |
| 330 | cinfo.do_block_smoothing = 0; |
| 331 | |
| 332 | /* default format is RGB */ |
| 333 | cinfo.out_color_space = JCS_RGB; |
| 334 | |
| 335 | SkBitmap::Config config = prefConfig; |
| 336 | // if no user preference, see what the device recommends |
| 337 | if (config == SkBitmap::kNo_Config) |
| 338 | config = SkImageDecoder::GetDeviceConfig(); |
| 339 | |
| 340 | // only these make sense for jpegs |
| 341 | if (config != SkBitmap::kARGB_8888_Config && |
| 342 | config != SkBitmap::kARGB_4444_Config && |
| 343 | config != SkBitmap::kRGB_565_Config) { |
| 344 | config = SkBitmap::kARGB_8888_Config; |
| 345 | } |
| 346 | |
| 347 | #ifdef ANDROID_RGB |
| 348 | cinfo.dither_mode = JDITHER_NONE; |
| 349 | if (config == SkBitmap::kARGB_8888_Config) { |
| 350 | cinfo.out_color_space = JCS_RGBA_8888; |
| 351 | } else if (config == SkBitmap::kRGB_565_Config) { |
| 352 | if (sampleSize == 1) { |
| 353 | // SkScaledBitmapSampler can't handle RGB_565 yet, |
| 354 | // so don't even try. |
| 355 | cinfo.out_color_space = JCS_RGB_565; |
| 356 | if (this->getDitherImage()) { |
| 357 | cinfo.dither_mode = JDITHER_ORDERED; |
| 358 | } |
| 359 | } |
| 360 | } |
| 361 | #endif |
| 362 | |
| 363 | /* image_width and image_height are the original dimensions, available |
| 364 | after jpeg_read_header(). To see the scaled dimensions, we have to call |
| 365 | jpeg_start_decompress(), and then read output_width and output_height. |
| 366 | */ |
| 367 | if (!jpeg_start_decompress(&cinfo)) { |
| 368 | return return_false(cinfo, *bm, "start_decompress"); |
| 369 | } |
| 370 | |
| 371 | /* If we need to better match the request, we might examine the image and |
| 372 | output dimensions, and determine if the downsampling jpeg provided is |
| 373 | not sufficient. If so, we can recompute a modified sampleSize value to |
| 374 | make up the difference. |
| 375 | |
| 376 | To skip this additional scaling, just set sampleSize = 1; below. |
| 377 | */ |
| 378 | sampleSize = sampleSize * cinfo.output_width / cinfo.image_width; |
| 379 | |
| 380 | |
| 381 | // should we allow the Chooser (if present) to pick a config for us??? |
| 382 | if (!this->chooseFromOneChoice(config, cinfo.output_width, |
| 383 | cinfo.output_height)) { |
| 384 | return return_false(cinfo, *bm, "chooseFromOneChoice"); |
| 385 | } |
| 386 | |
| 387 | #ifdef ANDROID_RGB |
| 388 | /* short-circuit the SkScaledBitmapSampler when possible, as this gives |
| 389 | a significant performance boost. |
| 390 | */ |
| 391 | if (sampleSize == 1 && |
| 392 | ((config == SkBitmap::kARGB_8888_Config && |
| 393 | cinfo.out_color_space == JCS_RGBA_8888) || |
| 394 | (config == SkBitmap::kRGB_565_Config && |
| 395 | cinfo.out_color_space == JCS_RGB_565))) |
| 396 | { |
| 397 | bm->setConfig(config, cinfo.output_width, cinfo.output_height); |
| 398 | bm->setIsOpaque(true); |
| 399 | if (SkImageDecoder::kDecodeBounds_Mode == mode) { |
| 400 | return true; |
| 401 | } |
| 402 | if (!this->allocPixelRef(bm, NULL)) { |
| 403 | return return_false(cinfo, *bm, "allocPixelRef"); |
| 404 | } |
| 405 | SkAutoLockPixels alp(*bm); |
| 406 | JSAMPLE* rowptr = (JSAMPLE*)bm->getPixels(); |
| 407 | INT32 const bpr = bm->rowBytes(); |
| 408 | |
| 409 | while (cinfo.output_scanline < cinfo.output_height) { |
| 410 | int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1); |
| 411 | // if row_count == 0, then we didn't get a scanline, so abort. |
| 412 | // if we supported partial images, we might return true in this case |
| 413 | if (0 == row_count) { |
| 414 | return return_false(cinfo, *bm, "read_scanlines"); |
| 415 | } |
| 416 | if (this->shouldCancelDecode()) { |
| 417 | return return_false(cinfo, *bm, "shouldCancelDecode"); |
| 418 | } |
| 419 | rowptr += bpr; |
| 420 | } |
| 421 | jpeg_finish_decompress(&cinfo); |
| 422 | return true; |
| 423 | } |
| 424 | #endif |
| 425 | |
| 426 | // check for supported formats |
| 427 | SkScaledBitmapSampler::SrcConfig sc; |
| 428 | if (3 == cinfo.out_color_components && JCS_RGB == cinfo.out_color_space) { |
| 429 | sc = SkScaledBitmapSampler::kRGB; |
| 430 | #ifdef ANDROID_RGB |
| 431 | } else if (JCS_RGBA_8888 == cinfo.out_color_space) { |
| 432 | sc = SkScaledBitmapSampler::kRGBX; |
| 433 | //} else if (JCS_RGB_565 == cinfo.out_color_space) { |
| 434 | // sc = SkScaledBitmapSampler::kRGB_565; |
| 435 | #endif |
| 436 | } else if (1 == cinfo.out_color_components && |
| 437 | JCS_GRAYSCALE == cinfo.out_color_space) { |
| 438 | sc = SkScaledBitmapSampler::kGray; |
| 439 | } else { |
| 440 | return return_false(cinfo, *bm, "jpeg colorspace"); |
| 441 | } |
| 442 | |
| 443 | SkScaledBitmapSampler sampler(cinfo.output_width, cinfo.output_height, |
| 444 | sampleSize); |
| 445 | |
| 446 | bm->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight()); |
| 447 | // jpegs are always opauqe (i.e. have no per-pixel alpha) |
| 448 | bm->setIsOpaque(true); |
| 449 | |
| 450 | if (SkImageDecoder::kDecodeBounds_Mode == mode) { |
| 451 | return true; |
| 452 | } |
| 453 | if (!this->allocPixelRef(bm, NULL)) { |
| 454 | return return_false(cinfo, *bm, "allocPixelRef"); |
| 455 | } |
| 456 | |
| 457 | SkAutoLockPixels alp(*bm); |
| 458 | if (!sampler.begin(bm, sc, this->getDitherImage())) { |
| 459 | return return_false(cinfo, *bm, "sampler.begin"); |
| 460 | } |
| 461 | |
| 462 | uint8_t* srcRow = (uint8_t*)srcStorage.alloc(cinfo.output_width * 4); |
| 463 | |
| 464 | // Possibly skip initial rows [sampler.srcY0] |
| 465 | if (!skip_src_rows(&cinfo, srcRow, sampler.srcY0())) { |
| 466 | return return_false(cinfo, *bm, "skip rows"); |
| 467 | } |
| 468 | |
| 469 | // now loop through scanlines until y == bm->height() - 1 |
| 470 | for (int y = 0;; y++) { |
| 471 | JSAMPLE* rowptr = (JSAMPLE*)srcRow; |
| 472 | int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1); |
| 473 | if (0 == row_count) { |
| 474 | return return_false(cinfo, *bm, "read_scanlines"); |
| 475 | } |
| 476 | if (this->shouldCancelDecode()) { |
| 477 | return return_false(cinfo, *bm, "shouldCancelDecode"); |
| 478 | } |
| 479 | |
| 480 | sampler.next(srcRow); |
| 481 | if (bm->height() - 1 == y) { |
| 482 | // we're done |
| 483 | break; |
| 484 | } |
| 485 | |
| 486 | if (!skip_src_rows(&cinfo, srcRow, sampler.srcDY() - 1)) { |
| 487 | return return_false(cinfo, *bm, "skip rows"); |
| 488 | } |
| 489 | } |
| 490 | |
| 491 | // we formally skip the rest, so we don't get a complaint from libjpeg |
| 492 | if (!skip_src_rows(&cinfo, srcRow, |
| 493 | cinfo.output_height - cinfo.output_scanline)) { |
| 494 | return return_false(cinfo, *bm, "skip rows"); |
| 495 | } |
| 496 | jpeg_finish_decompress(&cinfo); |
| 497 | |
| 498 | // SkDebugf("------------------- bm2 size %d [%d %d] %d\n", bm->getSize(), bm->width(), bm->height(), bm->config()); |
| 499 | return true; |
| 500 | } |
| 501 | |
| 502 | /////////////////////////////////////////////////////////////////////////////// |
| 503 | |
| 504 | #ifdef SK_SUPPORT_IMAGE_ENCODE |
| 505 | |
| 506 | #include "SkColorPriv.h" |
| 507 | |
| 508 | // taken from jcolor.c in libjpeg |
| 509 | #if 0 // 16bit - precise but slow |
| 510 | #define CYR 19595 // 0.299 |
| 511 | #define CYG 38470 // 0.587 |
| 512 | #define CYB 7471 // 0.114 |
| 513 | |
| 514 | #define CUR -11059 // -0.16874 |
| 515 | #define CUG -21709 // -0.33126 |
| 516 | #define CUB 32768 // 0.5 |
| 517 | |
| 518 | #define CVR 32768 // 0.5 |
| 519 | #define CVG -27439 // -0.41869 |
| 520 | #define CVB -5329 // -0.08131 |
| 521 | |
| 522 | #define CSHIFT 16 |
| 523 | #else // 8bit - fast, slightly less precise |
| 524 | #define CYR 77 // 0.299 |
| 525 | #define CYG 150 // 0.587 |
| 526 | #define CYB 29 // 0.114 |
| 527 | |
| 528 | #define CUR -43 // -0.16874 |
| 529 | #define CUG -85 // -0.33126 |
| 530 | #define CUB 128 // 0.5 |
| 531 | |
| 532 | #define CVR 128 // 0.5 |
| 533 | #define CVG -107 // -0.41869 |
| 534 | #define CVB -21 // -0.08131 |
| 535 | |
| 536 | #define CSHIFT 8 |
| 537 | #endif |
| 538 | |
| 539 | static void rgb2yuv_32(uint8_t dst[], SkPMColor c) { |
| 540 | int r = SkGetPackedR32(c); |
| 541 | int g = SkGetPackedG32(c); |
| 542 | int b = SkGetPackedB32(c); |
| 543 | |
| 544 | int y = ( CYR*r + CYG*g + CYB*b ) >> CSHIFT; |
| 545 | int u = ( CUR*r + CUG*g + CUB*b ) >> CSHIFT; |
| 546 | int v = ( CVR*r + CVG*g + CVB*b ) >> CSHIFT; |
| 547 | |
| 548 | dst[0] = SkToU8(y); |
| 549 | dst[1] = SkToU8(u + 128); |
| 550 | dst[2] = SkToU8(v + 128); |
| 551 | } |
| 552 | |
| 553 | static void rgb2yuv_4444(uint8_t dst[], U16CPU c) { |
| 554 | int r = SkGetPackedR4444(c); |
| 555 | int g = SkGetPackedG4444(c); |
| 556 | int b = SkGetPackedB4444(c); |
| 557 | |
| 558 | int y = ( CYR*r + CYG*g + CYB*b ) >> (CSHIFT - 4); |
| 559 | int u = ( CUR*r + CUG*g + CUB*b ) >> (CSHIFT - 4); |
| 560 | int v = ( CVR*r + CVG*g + CVB*b ) >> (CSHIFT - 4); |
| 561 | |
| 562 | dst[0] = SkToU8(y); |
| 563 | dst[1] = SkToU8(u + 128); |
| 564 | dst[2] = SkToU8(v + 128); |
| 565 | } |
| 566 | |
| 567 | static void rgb2yuv_16(uint8_t dst[], U16CPU c) { |
| 568 | int r = SkGetPackedR16(c); |
| 569 | int g = SkGetPackedG16(c); |
| 570 | int b = SkGetPackedB16(c); |
| 571 | |
| 572 | int y = ( 2*CYR*r + CYG*g + 2*CYB*b ) >> (CSHIFT - 2); |
| 573 | int u = ( 2*CUR*r + CUG*g + 2*CUB*b ) >> (CSHIFT - 2); |
| 574 | int v = ( 2*CVR*r + CVG*g + 2*CVB*b ) >> (CSHIFT - 2); |
| 575 | |
| 576 | dst[0] = SkToU8(y); |
| 577 | dst[1] = SkToU8(u + 128); |
| 578 | dst[2] = SkToU8(v + 128); |
| 579 | } |
| 580 | |
| 581 | /////////////////////////////////////////////////////////////////////////////// |
| 582 | |
| 583 | typedef void (*WriteScanline)(uint8_t* SK_RESTRICT dst, |
| 584 | const void* SK_RESTRICT src, int width, |
| 585 | const SkPMColor* SK_RESTRICT ctable); |
| 586 | |
| 587 | static void Write_32_YUV(uint8_t* SK_RESTRICT dst, |
| 588 | const void* SK_RESTRICT srcRow, int width, |
| 589 | const SkPMColor*) { |
| 590 | const uint32_t* SK_RESTRICT src = (const uint32_t*)srcRow; |
| 591 | while (--width >= 0) { |
| 592 | #ifdef WE_CONVERT_TO_YUV |
| 593 | rgb2yuv_32(dst, *src++); |
| 594 | #else |
| 595 | uint32_t c = *src++; |
| 596 | dst[0] = SkGetPackedR32(c); |
| 597 | dst[1] = SkGetPackedG32(c); |
| 598 | dst[2] = SkGetPackedB32(c); |
| 599 | #endif |
| 600 | dst += 3; |
| 601 | } |
| 602 | } |
| 603 | |
| 604 | static void Write_4444_YUV(uint8_t* SK_RESTRICT dst, |
| 605 | const void* SK_RESTRICT srcRow, int width, |
| 606 | const SkPMColor*) { |
| 607 | const SkPMColor16* SK_RESTRICT src = (const SkPMColor16*)srcRow; |
| 608 | while (--width >= 0) { |
| 609 | #ifdef WE_CONVERT_TO_YUV |
| 610 | rgb2yuv_4444(dst, *src++); |
| 611 | #else |
| 612 | SkPMColor16 c = *src++; |
| 613 | dst[0] = SkPacked4444ToR32(c); |
| 614 | dst[1] = SkPacked4444ToG32(c); |
| 615 | dst[2] = SkPacked4444ToB32(c); |
| 616 | #endif |
| 617 | dst += 3; |
| 618 | } |
| 619 | } |
| 620 | |
| 621 | static void Write_16_YUV(uint8_t* SK_RESTRICT dst, |
| 622 | const void* SK_RESTRICT srcRow, int width, |
| 623 | const SkPMColor*) { |
| 624 | const uint16_t* SK_RESTRICT src = (const uint16_t*)srcRow; |
| 625 | while (--width >= 0) { |
| 626 | #ifdef WE_CONVERT_TO_YUV |
| 627 | rgb2yuv_16(dst, *src++); |
| 628 | #else |
| 629 | uint16_t c = *src++; |
| 630 | dst[0] = SkPacked16ToR32(c); |
| 631 | dst[1] = SkPacked16ToG32(c); |
| 632 | dst[2] = SkPacked16ToB32(c); |
| 633 | #endif |
| 634 | dst += 3; |
| 635 | } |
| 636 | } |
| 637 | |
| 638 | static void Write_Index_YUV(uint8_t* SK_RESTRICT dst, |
| 639 | const void* SK_RESTRICT srcRow, int width, |
| 640 | const SkPMColor* SK_RESTRICT ctable) { |
| 641 | const uint8_t* SK_RESTRICT src = (const uint8_t*)srcRow; |
| 642 | while (--width >= 0) { |
| 643 | #ifdef WE_CONVERT_TO_YUV |
| 644 | rgb2yuv_32(dst, ctable[*src++]); |
| 645 | #else |
| 646 | uint32_t c = ctable[*src++]; |
| 647 | dst[0] = SkGetPackedR32(c); |
| 648 | dst[1] = SkGetPackedG32(c); |
| 649 | dst[2] = SkGetPackedB32(c); |
| 650 | #endif |
| 651 | dst += 3; |
| 652 | } |
| 653 | } |
| 654 | |
| 655 | static WriteScanline ChooseWriter(const SkBitmap& bm) { |
| 656 | switch (bm.config()) { |
| 657 | case SkBitmap::kARGB_8888_Config: |
| 658 | return Write_32_YUV; |
| 659 | case SkBitmap::kRGB_565_Config: |
| 660 | return Write_16_YUV; |
| 661 | case SkBitmap::kARGB_4444_Config: |
| 662 | return Write_4444_YUV; |
| 663 | case SkBitmap::kIndex8_Config: |
| 664 | return Write_Index_YUV; |
| 665 | default: |
| 666 | return NULL; |
| 667 | } |
| 668 | } |
| 669 | |
| 670 | struct sk_destination_mgr : jpeg_destination_mgr { |
| 671 | sk_destination_mgr(SkWStream* stream); |
| 672 | |
| 673 | SkWStream* fStream; |
| 674 | |
| 675 | enum { |
| 676 | kBufferSize = 1024 |
| 677 | }; |
| 678 | uint8_t fBuffer[kBufferSize]; |
| 679 | }; |
| 680 | |
| 681 | static void sk_init_destination(j_compress_ptr cinfo) { |
| 682 | sk_destination_mgr* dest = (sk_destination_mgr*)cinfo->dest; |
| 683 | |
| 684 | dest->next_output_byte = dest->fBuffer; |
| 685 | dest->free_in_buffer = sk_destination_mgr::kBufferSize; |
| 686 | } |
| 687 | |
| 688 | static boolean sk_empty_output_buffer(j_compress_ptr cinfo) { |
| 689 | sk_destination_mgr* dest = (sk_destination_mgr*)cinfo->dest; |
| 690 | |
| 691 | // if (!dest->fStream->write(dest->fBuffer, sk_destination_mgr::kBufferSize - dest->free_in_buffer)) |
| 692 | if (!dest->fStream->write(dest->fBuffer, sk_destination_mgr::kBufferSize)) { |
| 693 | ERREXIT(cinfo, JERR_FILE_WRITE); |
| 694 | return false; |
| 695 | } |
| 696 | |
| 697 | dest->next_output_byte = dest->fBuffer; |
| 698 | dest->free_in_buffer = sk_destination_mgr::kBufferSize; |
| 699 | return TRUE; |
| 700 | } |
| 701 | |
| 702 | static void sk_term_destination (j_compress_ptr cinfo) { |
| 703 | sk_destination_mgr* dest = (sk_destination_mgr*)cinfo->dest; |
| 704 | |
| 705 | size_t size = sk_destination_mgr::kBufferSize - dest->free_in_buffer; |
| 706 | if (size > 0) { |
| 707 | if (!dest->fStream->write(dest->fBuffer, size)) { |
| 708 | ERREXIT(cinfo, JERR_FILE_WRITE); |
| 709 | return; |
| 710 | } |
| 711 | } |
| 712 | dest->fStream->flush(); |
| 713 | } |
| 714 | |
| 715 | sk_destination_mgr::sk_destination_mgr(SkWStream* stream) |
| 716 | : fStream(stream) { |
| 717 | this->init_destination = sk_init_destination; |
| 718 | this->empty_output_buffer = sk_empty_output_buffer; |
| 719 | this->term_destination = sk_term_destination; |
| 720 | } |
| 721 | |
| 722 | class SkJPEGImageEncoder : public SkImageEncoder { |
| 723 | protected: |
| 724 | virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality) { |
| 725 | #ifdef TIME_ENCODE |
| 726 | AutoTimeMillis atm("JPEG Encode"); |
| 727 | #endif |
| 728 | |
| 729 | const WriteScanline writer = ChooseWriter(bm); |
| 730 | if (NULL == writer) { |
| 731 | return false; |
| 732 | } |
| 733 | |
| 734 | SkAutoLockPixels alp(bm); |
| 735 | if (NULL == bm.getPixels()) { |
| 736 | return false; |
| 737 | } |
| 738 | |
| 739 | jpeg_compress_struct cinfo; |
| 740 | sk_error_mgr sk_err; |
| 741 | sk_destination_mgr sk_wstream(stream); |
| 742 | |
| 743 | // allocate these before set call setjmp |
| 744 | SkAutoMalloc oneRow; |
| 745 | SkAutoLockColors ctLocker; |
| 746 | |
| 747 | cinfo.err = jpeg_std_error(&sk_err); |
| 748 | sk_err.error_exit = sk_error_exit; |
| 749 | if (setjmp(sk_err.fJmpBuf)) { |
| 750 | return false; |
| 751 | } |
| 752 | jpeg_create_compress(&cinfo); |
| 753 | |
| 754 | cinfo.dest = &sk_wstream; |
| 755 | cinfo.image_width = bm.width(); |
| 756 | cinfo.image_height = bm.height(); |
| 757 | cinfo.input_components = 3; |
| 758 | #ifdef WE_CONVERT_TO_YUV |
| 759 | cinfo.in_color_space = JCS_YCbCr; |
| 760 | #else |
| 761 | cinfo.in_color_space = JCS_RGB; |
| 762 | #endif |
| 763 | cinfo.input_gamma = 1; |
| 764 | |
| 765 | jpeg_set_defaults(&cinfo); |
| 766 | jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */); |
| 767 | cinfo.dct_method = JDCT_IFAST; |
| 768 | |
| 769 | jpeg_start_compress(&cinfo, TRUE); |
| 770 | |
| 771 | const int width = bm.width(); |
| 772 | uint8_t* oneRowP = (uint8_t*)oneRow.alloc(width * 3); |
| 773 | |
| 774 | const SkPMColor* colors = ctLocker.lockColors(bm); |
| 775 | const void* srcRow = bm.getPixels(); |
| 776 | |
| 777 | while (cinfo.next_scanline < cinfo.image_height) { |
| 778 | JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */ |
| 779 | |
| 780 | writer(oneRowP, srcRow, width, colors); |
| 781 | row_pointer[0] = oneRowP; |
| 782 | (void) jpeg_write_scanlines(&cinfo, row_pointer, 1); |
| 783 | srcRow = (const void*)((const char*)srcRow + bm.rowBytes()); |
| 784 | } |
| 785 | |
| 786 | jpeg_finish_compress(&cinfo); |
| 787 | jpeg_destroy_compress(&cinfo); |
| 788 | |
| 789 | return true; |
| 790 | } |
| 791 | }; |
| 792 | |
| 793 | SkImageEncoder* SkImageEncoder_JPEG_Factory(); |
| 794 | SkImageEncoder* SkImageEncoder_JPEG_Factory() { |
| 795 | return SkNEW(SkJPEGImageEncoder); |
| 796 | } |
| 797 | |
| 798 | #endif /* SK_SUPPORT_IMAGE_ENCODE */ |
| 799 | |
| 800 | ////////////////////////////////////////////////////////////////////////// |
| 801 | ////////////////////////////////////////////////////////////////////////// |
| 802 | |
| 803 | #ifdef SK_DEBUG |
| 804 | |
| 805 | void SkImageDecoder::UnitTest() { |
| 806 | SkBitmap bm; |
| 807 | |
| 808 | (void)SkImageDecoder::DecodeFile("logo.jpg", &bm); |
| 809 | } |
| 810 | |
| 811 | #endif |