1 /* 2 * Copyright (C)2009-2015, 2017, 2020-2021 D. R. Commander. 3 * All Rights Reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * - Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * - Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * - Neither the name of the libjpeg-turbo Project nor the names of its 14 * contributors may be used to endorse or promote products derived from this 15 * software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS", 18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE 21 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #ifndef __TURBOJPEG_H__ 31 #define __TURBOJPEG_H__ 32 33 #if defined(_WIN32) && defined(DLLDEFINE) 34 #define DLLEXPORT __declspec(dllexport) 35 #else 36 #define DLLEXPORT 37 #endif 38 #define DLLCALL 39 40 41 /** 42 * @addtogroup TurboJPEG 43 * TurboJPEG API. This API provides an interface for generating, decoding, and 44 * transforming planar YUV and JPEG images in memory. 45 * 46 * @anchor YUVnotes 47 * YUV Image Format Notes 48 * ---------------------- 49 * Technically, the JPEG format uses the YCbCr colorspace (which is technically 50 * not a colorspace but a color transform), but per the convention of the 51 * digital video community, the TurboJPEG API uses "YUV" to refer to an image 52 * format consisting of Y, Cb, and Cr image planes. 53 * 54 * Each plane is simply a 2D array of bytes, each byte representing the value 55 * of one of the components (Y, Cb, or Cr) at a particular location in the 56 * image. The width and height of each plane are determined by the image 57 * width, height, and level of chrominance subsampling. The luminance plane 58 * width is the image width padded to the nearest multiple of the horizontal 59 * subsampling factor (2 in the case of 4:2:0 and 4:2:2, 4 in the case of 60 * 4:1:1, 1 in the case of 4:4:4 or grayscale.) Similarly, the luminance plane 61 * height is the image height padded to the nearest multiple of the vertical 62 * subsampling factor (2 in the case of 4:2:0 or 4:4:0, 1 in the case of 4:4:4 63 * or grayscale.) This is irrespective of any additional padding that may be 64 * specified as an argument to the various YUV functions. The chrominance 65 * plane width is equal to the luminance plane width divided by the horizontal 66 * subsampling factor, and the chrominance plane height is equal to the 67 * luminance plane height divided by the vertical subsampling factor. 68 * 69 * For example, if the source image is 35 x 35 pixels and 4:2:2 subsampling is 70 * used, then the luminance plane would be 36 x 35 bytes, and each of the 71 * chrominance planes would be 18 x 35 bytes. If you specify a line padding of 72 * 4 bytes on top of this, then the luminance plane would be 36 x 35 bytes, and 73 * each of the chrominance planes would be 20 x 35 bytes. 74 * 75 * @{ 76 */ 77 78 79 /** 80 * The number of chrominance subsampling options 81 */ 82 #define TJ_NUMSAMP 6 83 84 /** 85 * Chrominance subsampling options. 86 * When pixels are converted from RGB to YCbCr (see #TJCS_YCbCr) or from CMYK 87 * to YCCK (see #TJCS_YCCK) as part of the JPEG compression process, some of 88 * the Cb and Cr (chrominance) components can be discarded or averaged together 89 * to produce a smaller image with little perceptible loss of image clarity 90 * (the human eye is more sensitive to small changes in brightness than to 91 * small changes in color.) This is called "chrominance subsampling". 92 */ 93 enum TJSAMP { 94 /** 95 * 4:4:4 chrominance subsampling (no chrominance subsampling). The JPEG or 96 * YUV image will contain one chrominance component for every pixel in the 97 * source image. 98 */ 99 TJSAMP_444 = 0, 100 /** 101 * 4:2:2 chrominance subsampling. The JPEG or YUV image will contain one 102 * chrominance component for every 2x1 block of pixels in the source image. 103 */ 104 TJSAMP_422, 105 /** 106 * 4:2:0 chrominance subsampling. The JPEG or YUV image will contain one 107 * chrominance component for every 2x2 block of pixels in the source image. 108 */ 109 TJSAMP_420, 110 /** 111 * Grayscale. The JPEG or YUV image will contain no chrominance components. 112 */ 113 TJSAMP_GRAY, 114 /** 115 * 4:4:0 chrominance subsampling. The JPEG or YUV image will contain one 116 * chrominance component for every 1x2 block of pixels in the source image. 117 * 118 * @note 4:4:0 subsampling is not fully accelerated in libjpeg-turbo. 119 */ 120 TJSAMP_440, 121 /** 122 * 4:1:1 chrominance subsampling. The JPEG or YUV image will contain one 123 * chrominance component for every 4x1 block of pixels in the source image. 124 * JPEG images compressed with 4:1:1 subsampling will be almost exactly the 125 * same size as those compressed with 4:2:0 subsampling, and in the 126 * aggregate, both subsampling methods produce approximately the same 127 * perceptual quality. However, 4:1:1 is better able to reproduce sharp 128 * horizontal features. 129 * 130 * @note 4:1:1 subsampling is not fully accelerated in libjpeg-turbo. 131 */ 132 TJSAMP_411 133 }; 134 135 /** 136 * MCU block width (in pixels) for a given level of chrominance subsampling. 137 * MCU block sizes: 138 * - 8x8 for no subsampling or grayscale 139 * - 16x8 for 4:2:2 140 * - 8x16 for 4:4:0 141 * - 16x16 for 4:2:0 142 * - 32x8 for 4:1:1 143 */ 144 static const int tjMCUWidth[TJ_NUMSAMP] = { 8, 16, 16, 8, 8, 32 }; 145 146 /** 147 * MCU block height (in pixels) for a given level of chrominance subsampling. 148 * MCU block sizes: 149 * - 8x8 for no subsampling or grayscale 150 * - 16x8 for 4:2:2 151 * - 8x16 for 4:4:0 152 * - 16x16 for 4:2:0 153 * - 32x8 for 4:1:1 154 */ 155 static const int tjMCUHeight[TJ_NUMSAMP] = { 8, 8, 16, 8, 16, 8 }; 156 157 158 /** 159 * The number of pixel formats 160 */ 161 #define TJ_NUMPF 12 162 163 /** 164 * Pixel formats 165 */ 166 enum TJPF { 167 /** 168 * RGB pixel format. The red, green, and blue components in the image are 169 * stored in 3-byte pixels in the order R, G, B from lowest to highest byte 170 * address within each pixel. 171 */ 172 TJPF_RGB = 0, 173 /** 174 * BGR pixel format. The red, green, and blue components in the image are 175 * stored in 3-byte pixels in the order B, G, R from lowest to highest byte 176 * address within each pixel. 177 */ 178 TJPF_BGR, 179 /** 180 * RGBX pixel format. The red, green, and blue components in the image are 181 * stored in 4-byte pixels in the order R, G, B from lowest to highest byte 182 * address within each pixel. The X component is ignored when compressing 183 * and undefined when decompressing. 184 */ 185 TJPF_RGBX, 186 /** 187 * BGRX pixel format. The red, green, and blue components in the image are 188 * stored in 4-byte pixels in the order B, G, R from lowest to highest byte 189 * address within each pixel. The X component is ignored when compressing 190 * and undefined when decompressing. 191 */ 192 TJPF_BGRX, 193 /** 194 * XBGR pixel format. The red, green, and blue components in the image are 195 * stored in 4-byte pixels in the order R, G, B from highest to lowest byte 196 * address within each pixel. The X component is ignored when compressing 197 * and undefined when decompressing. 198 */ 199 TJPF_XBGR, 200 /** 201 * XRGB pixel format. The red, green, and blue components in the image are 202 * stored in 4-byte pixels in the order B, G, R from highest to lowest byte 203 * address within each pixel. The X component is ignored when compressing 204 * and undefined when decompressing. 205 */ 206 TJPF_XRGB, 207 /** 208 * Grayscale pixel format. Each 1-byte pixel represents a luminance 209 * (brightness) level from 0 to 255. 210 */ 211 TJPF_GRAY, 212 /** 213 * RGBA pixel format. This is the same as @ref TJPF_RGBX, except that when 214 * decompressing, the X component is guaranteed to be 0xFF, which can be 215 * interpreted as an opaque alpha channel. 216 */ 217 TJPF_RGBA, 218 /** 219 * BGRA pixel format. This is the same as @ref TJPF_BGRX, except that when 220 * decompressing, the X component is guaranteed to be 0xFF, which can be 221 * interpreted as an opaque alpha channel. 222 */ 223 TJPF_BGRA, 224 /** 225 * ABGR pixel format. This is the same as @ref TJPF_XBGR, except that when 226 * decompressing, the X component is guaranteed to be 0xFF, which can be 227 * interpreted as an opaque alpha channel. 228 */ 229 TJPF_ABGR, 230 /** 231 * ARGB pixel format. This is the same as @ref TJPF_XRGB, except that when 232 * decompressing, the X component is guaranteed to be 0xFF, which can be 233 * interpreted as an opaque alpha channel. 234 */ 235 TJPF_ARGB, 236 /** 237 * CMYK pixel format. Unlike RGB, which is an additive color model used 238 * primarily for display, CMYK (Cyan/Magenta/Yellow/Key) is a subtractive 239 * color model used primarily for printing. In the CMYK color model, the 240 * value of each color component typically corresponds to an amount of cyan, 241 * magenta, yellow, or black ink that is applied to a white background. In 242 * order to convert between CMYK and RGB, it is necessary to use a color 243 * management system (CMS.) A CMS will attempt to map colors within the 244 * printer's gamut to perceptually similar colors in the display's gamut and 245 * vice versa, but the mapping is typically not 1:1 or reversible, nor can it 246 * be defined with a simple formula. Thus, such a conversion is out of scope 247 * for a codec library. However, the TurboJPEG API allows for compressing 248 * CMYK pixels into a YCCK JPEG image (see #TJCS_YCCK) and decompressing YCCK 249 * JPEG images into CMYK pixels. 250 */ 251 TJPF_CMYK, 252 /** 253 * Unknown pixel format. Currently this is only used by #tjLoadImage(). 254 */ 255 TJPF_UNKNOWN = -1 256 }; 257 258 /** 259 * Red offset (in bytes) for a given pixel format. This specifies the number 260 * of bytes that the red component is offset from the start of the pixel. For 261 * instance, if a pixel of format TJ_BGRX is stored in <tt>char pixel[]</tt>, 262 * then the red component will be <tt>pixel[tjRedOffset[TJ_BGRX]]</tt>. This 263 * will be -1 if the pixel format does not have a red component. 264 */ 265 static const int tjRedOffset[TJ_NUMPF] = { 266 0, 2, 0, 2, 3, 1, -1, 0, 2, 3, 1, -1 267 }; 268 /** 269 * Green offset (in bytes) for a given pixel format. This specifies the number 270 * of bytes that the green component is offset from the start of the pixel. 271 * For instance, if a pixel of format TJ_BGRX is stored in 272 * <tt>char pixel[]</tt>, then the green component will be 273 * <tt>pixel[tjGreenOffset[TJ_BGRX]]</tt>. This will be -1 if the pixel format 274 * does not have a green component. 275 */ 276 static const int tjGreenOffset[TJ_NUMPF] = { 277 1, 1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1 278 }; 279 /** 280 * Blue offset (in bytes) for a given pixel format. This specifies the number 281 * of bytes that the Blue component is offset from the start of the pixel. For 282 * instance, if a pixel of format TJ_BGRX is stored in <tt>char pixel[]</tt>, 283 * then the blue component will be <tt>pixel[tjBlueOffset[TJ_BGRX]]</tt>. This 284 * will be -1 if the pixel format does not have a blue component. 285 */ 286 static const int tjBlueOffset[TJ_NUMPF] = { 287 2, 0, 2, 0, 1, 3, -1, 2, 0, 1, 3, -1 288 }; 289 /** 290 * Alpha offset (in bytes) for a given pixel format. This specifies the number 291 * of bytes that the Alpha component is offset from the start of the pixel. 292 * For instance, if a pixel of format TJ_BGRA is stored in 293 * <tt>char pixel[]</tt>, then the alpha component will be 294 * <tt>pixel[tjAlphaOffset[TJ_BGRA]]</tt>. This will be -1 if the pixel format 295 * does not have an alpha component. 296 */ 297 static const int tjAlphaOffset[TJ_NUMPF] = { 298 -1, -1, -1, -1, -1, -1, -1, 3, 3, 0, 0, -1 299 }; 300 /** 301 * Pixel size (in bytes) for a given pixel format 302 */ 303 static const int tjPixelSize[TJ_NUMPF] = { 304 3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 4, 4 305 }; 306 307 308 /** 309 * The number of JPEG colorspaces 310 */ 311 #define TJ_NUMCS 5 312 313 /** 314 * JPEG colorspaces 315 */ 316 enum TJCS { 317 /** 318 * RGB colorspace. When compressing the JPEG image, the R, G, and B 319 * components in the source image are reordered into image planes, but no 320 * colorspace conversion or subsampling is performed. RGB JPEG images can be 321 * decompressed to any of the extended RGB pixel formats or grayscale, but 322 * they cannot be decompressed to YUV images. 323 */ 324 TJCS_RGB = 0, 325 /** 326 * YCbCr colorspace. YCbCr is not an absolute colorspace but rather a 327 * mathematical transformation of RGB designed solely for storage and 328 * transmission. YCbCr images must be converted to RGB before they can 329 * actually be displayed. In the YCbCr colorspace, the Y (luminance) 330 * component represents the black & white portion of the original image, and 331 * the Cb and Cr (chrominance) components represent the color portion of the 332 * original image. Originally, the analog equivalent of this transformation 333 * allowed the same signal to drive both black & white and color televisions, 334 * but JPEG images use YCbCr primarily because it allows the color data to be 335 * optionally subsampled for the purposes of reducing bandwidth or disk 336 * space. YCbCr is the most common JPEG colorspace, and YCbCr JPEG images 337 * can be compressed from and decompressed to any of the extended RGB pixel 338 * formats or grayscale, or they can be decompressed to YUV planar images. 339 */ 340 TJCS_YCbCr, 341 /** 342 * Grayscale colorspace. The JPEG image retains only the luminance data (Y 343 * component), and any color data from the source image is discarded. 344 * Grayscale JPEG images can be compressed from and decompressed to any of 345 * the extended RGB pixel formats or grayscale, or they can be decompressed 346 * to YUV planar images. 347 */ 348 TJCS_GRAY, 349 /** 350 * CMYK colorspace. When compressing the JPEG image, the C, M, Y, and K 351 * components in the source image are reordered into image planes, but no 352 * colorspace conversion or subsampling is performed. CMYK JPEG images can 353 * only be decompressed to CMYK pixels. 354 */ 355 TJCS_CMYK, 356 /** 357 * YCCK colorspace. YCCK (AKA "YCbCrK") is not an absolute colorspace but 358 * rather a mathematical transformation of CMYK designed solely for storage 359 * and transmission. It is to CMYK as YCbCr is to RGB. CMYK pixels can be 360 * reversibly transformed into YCCK, and as with YCbCr, the chrominance 361 * components in the YCCK pixels can be subsampled without incurring major 362 * perceptual loss. YCCK JPEG images can only be compressed from and 363 * decompressed to CMYK pixels. 364 */ 365 TJCS_YCCK 366 }; 367 368 369 /** 370 * The uncompressed source/destination image is stored in bottom-up (Windows, 371 * OpenGL) order, not top-down (X11) order. 372 */ 373 #define TJFLAG_BOTTOMUP 2 374 /** 375 * When decompressing an image that was compressed using chrominance 376 * subsampling, use the fastest chrominance upsampling algorithm available in 377 * the underlying codec. The default is to use smooth upsampling, which 378 * creates a smooth transition between neighboring chrominance components in 379 * order to reduce upsampling artifacts in the decompressed image. 380 */ 381 #define TJFLAG_FASTUPSAMPLE 256 382 /** 383 * Disable buffer (re)allocation. If passed to one of the JPEG compression or 384 * transform functions, this flag will cause those functions to generate an 385 * error if the JPEG image buffer is invalid or too small rather than 386 * attempting to allocate or reallocate that buffer. This reproduces the 387 * behavior of earlier versions of TurboJPEG. 388 */ 389 #define TJFLAG_NOREALLOC 1024 390 /** 391 * Use the fastest DCT/IDCT algorithm available in the underlying codec. The 392 * default if this flag is not specified is implementation-specific. For 393 * example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast 394 * algorithm by default when compressing, because this has been shown to have 395 * only a very slight effect on accuracy, but it uses the accurate algorithm 396 * when decompressing, because this has been shown to have a larger effect. 397 */ 398 #define TJFLAG_FASTDCT 2048 399 /** 400 * Use the most accurate DCT/IDCT algorithm available in the underlying codec. 401 * The default if this flag is not specified is implementation-specific. For 402 * example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast 403 * algorithm by default when compressing, because this has been shown to have 404 * only a very slight effect on accuracy, but it uses the accurate algorithm 405 * when decompressing, because this has been shown to have a larger effect. 406 */ 407 #define TJFLAG_ACCURATEDCT 4096 408 /** 409 * Immediately discontinue the current compression/decompression/transform 410 * operation if the underlying codec throws a warning (non-fatal error). The 411 * default behavior is to allow the operation to complete unless a fatal error 412 * is encountered. 413 */ 414 #define TJFLAG_STOPONWARNING 8192 415 /** 416 * Use progressive entropy coding in JPEG images generated by the compression 417 * and transform functions. Progressive entropy coding will generally improve 418 * compression relative to baseline entropy coding (the default), but it will 419 * reduce compression and decompression performance considerably. 420 */ 421 #define TJFLAG_PROGRESSIVE 16384 422 /** 423 * Limit the number of progressive JPEG scans that the decompression and 424 * transform functions will process. If a progressive JPEG image contains an 425 * unreasonably large number of scans, then this flag will cause the 426 * decompression and transform functions to return an error. The primary 427 * purpose of this is to allow security-critical applications to guard against 428 * an exploit of the progressive JPEG format described in 429 * <a href="https://libjpeg-turbo.org/pmwiki/uploads/About/TwoIssueswiththeJPEGStandard.pdf" target="_blank">this report</a>. 430 */ 431 #define TJFLAG_LIMITSCANS 32768 432 433 434 /** 435 * The number of error codes 436 */ 437 #define TJ_NUMERR 2 438 439 /** 440 * Error codes 441 */ 442 enum TJERR { 443 /** 444 * The error was non-fatal and recoverable, but the image may still be 445 * corrupt. 446 */ 447 TJERR_WARNING = 0, 448 /** 449 * The error was fatal and non-recoverable. 450 */ 451 TJERR_FATAL 452 }; 453 454 455 /** 456 * The number of transform operations 457 */ 458 #define TJ_NUMXOP 8 459 460 /** 461 * Transform operations for #tjTransform() 462 */ 463 enum TJXOP { 464 /** 465 * Do not transform the position of the image pixels 466 */ 467 TJXOP_NONE = 0, 468 /** 469 * Flip (mirror) image horizontally. This transform is imperfect if there 470 * are any partial MCU blocks on the right edge (see #TJXOPT_PERFECT.) 471 */ 472 TJXOP_HFLIP, 473 /** 474 * Flip (mirror) image vertically. This transform is imperfect if there are 475 * any partial MCU blocks on the bottom edge (see #TJXOPT_PERFECT.) 476 */ 477 TJXOP_VFLIP, 478 /** 479 * Transpose image (flip/mirror along upper left to lower right axis.) This 480 * transform is always perfect. 481 */ 482 TJXOP_TRANSPOSE, 483 /** 484 * Transverse transpose image (flip/mirror along upper right to lower left 485 * axis.) This transform is imperfect if there are any partial MCU blocks in 486 * the image (see #TJXOPT_PERFECT.) 487 */ 488 TJXOP_TRANSVERSE, 489 /** 490 * Rotate image clockwise by 90 degrees. This transform is imperfect if 491 * there are any partial MCU blocks on the bottom edge (see 492 * #TJXOPT_PERFECT.) 493 */ 494 TJXOP_ROT90, 495 /** 496 * Rotate image 180 degrees. This transform is imperfect if there are any 497 * partial MCU blocks in the image (see #TJXOPT_PERFECT.) 498 */ 499 TJXOP_ROT180, 500 /** 501 * Rotate image counter-clockwise by 90 degrees. This transform is imperfect 502 * if there are any partial MCU blocks on the right edge (see 503 * #TJXOPT_PERFECT.) 504 */ 505 TJXOP_ROT270 506 }; 507 508 509 /** 510 * This option will cause #tjTransform() to return an error if the transform is 511 * not perfect. Lossless transforms operate on MCU blocks, whose size depends 512 * on the level of chrominance subsampling used (see #tjMCUWidth 513 * and #tjMCUHeight.) If the image's width or height is not evenly divisible 514 * by the MCU block size, then there will be partial MCU blocks on the right 515 * and/or bottom edges. It is not possible to move these partial MCU blocks to 516 * the top or left of the image, so any transform that would require that is 517 * "imperfect." If this option is not specified, then any partial MCU blocks 518 * that cannot be transformed will be left in place, which will create 519 * odd-looking strips on the right or bottom edge of the image. 520 */ 521 #define TJXOPT_PERFECT 1 522 /** 523 * This option will cause #tjTransform() to discard any partial MCU blocks that 524 * cannot be transformed. 525 */ 526 #define TJXOPT_TRIM 2 527 /** 528 * This option will enable lossless cropping. See #tjTransform() for more 529 * information. 530 */ 531 #define TJXOPT_CROP 4 532 /** 533 * This option will discard the color data in the input image and produce 534 * a grayscale output image. 535 */ 536 #define TJXOPT_GRAY 8 537 /** 538 * This option will prevent #tjTransform() from outputting a JPEG image for 539 * this particular transform (this can be used in conjunction with a custom 540 * filter to capture the transformed DCT coefficients without transcoding 541 * them.) 542 */ 543 #define TJXOPT_NOOUTPUT 16 544 /** 545 * This option will enable progressive entropy coding in the output image 546 * generated by this particular transform. Progressive entropy coding will 547 * generally improve compression relative to baseline entropy coding (the 548 * default), but it will reduce compression and decompression performance 549 * considerably. 550 */ 551 #define TJXOPT_PROGRESSIVE 32 552 /** 553 * This option will prevent #tjTransform() from copying any extra markers 554 * (including EXIF and ICC profile data) from the source image to the output 555 * image. 556 */ 557 #define TJXOPT_COPYNONE 64 558 559 560 /** 561 * Scaling factor 562 */ 563 typedef struct { 564 /** 565 * Numerator 566 */ 567 int num; 568 /** 569 * Denominator 570 */ 571 int denom; 572 } tjscalingfactor; 573 574 /** 575 * Cropping region 576 */ 577 typedef struct { 578 /** 579 * The left boundary of the cropping region. This must be evenly divisible 580 * by the MCU block width (see #tjMCUWidth.) 581 */ 582 int x; 583 /** 584 * The upper boundary of the cropping region. This must be evenly divisible 585 * by the MCU block height (see #tjMCUHeight.) 586 */ 587 int y; 588 /** 589 * The width of the cropping region. Setting this to 0 is the equivalent of 590 * setting it to the width of the source JPEG image - x. 591 */ 592 int w; 593 /** 594 * The height of the cropping region. Setting this to 0 is the equivalent of 595 * setting it to the height of the source JPEG image - y. 596 */ 597 int h; 598 } tjregion; 599 600 /** 601 * Lossless transform 602 */ 603 typedef struct tjtransform { 604 /** 605 * Cropping region 606 */ 607 tjregion r; 608 /** 609 * One of the @ref TJXOP "transform operations" 610 */ 611 int op; 612 /** 613 * The bitwise OR of one of more of the @ref TJXOPT_CROP "transform options" 614 */ 615 int options; 616 /** 617 * Arbitrary data that can be accessed within the body of the callback 618 * function 619 */ 620 void *data; 621 /** 622 * A callback function that can be used to modify the DCT coefficients 623 * after they are losslessly transformed but before they are transcoded to a 624 * new JPEG image. This allows for custom filters or other transformations 625 * to be applied in the frequency domain. 626 * 627 * @param coeffs pointer to an array of transformed DCT coefficients. (NOTE: 628 * this pointer is not guaranteed to be valid once the callback returns, so 629 * applications wishing to hand off the DCT coefficients to another function 630 * or library should make a copy of them within the body of the callback.) 631 * 632 * @param arrayRegion #tjregion structure containing the width and height of 633 * the array pointed to by <tt>coeffs</tt> as well as its offset relative to 634 * the component plane. TurboJPEG implementations may choose to split each 635 * component plane into multiple DCT coefficient arrays and call the callback 636 * function once for each array. 637 * 638 * @param planeRegion #tjregion structure containing the width and height of 639 * the component plane to which <tt>coeffs</tt> belongs 640 * 641 * @param componentID ID number of the component plane to which 642 * <tt>coeffs</tt> belongs (Y, Cb, and Cr have, respectively, ID's of 0, 1, 643 * and 2 in typical JPEG images.) 644 * 645 * @param transformID ID number of the transformed image to which 646 * <tt>coeffs</tt> belongs. This is the same as the index of the transform 647 * in the <tt>transforms</tt> array that was passed to #tjTransform(). 648 * 649 * @param transform a pointer to a #tjtransform structure that specifies the 650 * parameters and/or cropping region for this transform 651 * 652 * @return 0 if the callback was successful, or -1 if an error occurred. 653 */ 654 int (*customFilter) (short *coeffs, tjregion arrayRegion, 655 tjregion planeRegion, int componentIndex, 656 int transformIndex, struct tjtransform *transform); 657 } tjtransform; 658 659 /** 660 * TurboJPEG instance handle 661 */ 662 typedef void *tjhandle; 663 664 665 /** 666 * Pad the given width to the nearest 32-bit boundary 667 */ 668 #define TJPAD(width) (((width) + 3) & (~3)) 669 670 /** 671 * Compute the scaled value of <tt>dimension</tt> using the given scaling 672 * factor. This macro performs the integer equivalent of <tt>ceil(dimension * 673 * scalingFactor)</tt>. 674 */ 675 #define TJSCALED(dimension, scalingFactor) \ 676 ((dimension * scalingFactor.num + scalingFactor.denom - 1) / \ 677 scalingFactor.denom) 678 679 680 #ifdef __cplusplus 681 extern "C" { 682 #endif 683 684 685 /** 686 * Create a TurboJPEG compressor instance. 687 * 688 * @return a handle to the newly-created instance, or NULL if an error 689 * occurred (see #tjGetErrorStr2().) 690 */ 691 DLLEXPORT tjhandle tjInitCompress(void); 692 693 694 /** 695 * Compress an RGB, grayscale, or CMYK image into a JPEG image. 696 * 697 * @param handle a handle to a TurboJPEG compressor or transformer instance 698 * 699 * @param srcBuf pointer to an image buffer containing RGB, grayscale, or 700 * CMYK pixels to be compressed 701 * 702 * @param width width (in pixels) of the source image 703 * 704 * @param pitch bytes per line in the source image. Normally, this should be 705 * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or 706 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image 707 * is padded to the nearest 32-bit boundary, as is the case for Windows 708 * bitmaps. You can also be clever and use this parameter to skip lines, etc. 709 * Setting this parameter to 0 is the equivalent of setting it to 710 * <tt>width * #tjPixelSize[pixelFormat]</tt>. 711 * 712 * @param height height (in pixels) of the source image 713 * 714 * @param pixelFormat pixel format of the source image (see @ref TJPF 715 * "Pixel formats".) 716 * 717 * @param jpegBuf address of a pointer to an image buffer that will receive the 718 * JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer 719 * to accommodate the size of the JPEG image. Thus, you can choose to: 720 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and 721 * let TurboJPEG grow the buffer as needed, 722 * -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer 723 * for you, or 724 * -# pre-allocate the buffer to a "worst case" size determined by calling 725 * #tjBufSize(). This should ensure that the buffer never has to be 726 * re-allocated (setting #TJFLAG_NOREALLOC guarantees that it won't be.) 727 * . 728 * If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your 729 * pre-allocated buffer. In any case, unless you have set #TJFLAG_NOREALLOC, 730 * you should always check <tt>*jpegBuf</tt> upon return from this function, as 731 * it may have changed. 732 * 733 * @param jpegSize pointer to an unsigned long variable that holds the size of 734 * the JPEG image buffer. If <tt>*jpegBuf</tt> points to a pre-allocated 735 * buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer. 736 * Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in 737 * bytes.) If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being 738 * reused from a previous call to one of the JPEG compression functions, then 739 * <tt>*jpegSize</tt> is ignored. 740 * 741 * @param jpegSubsamp the level of chrominance subsampling to be used when 742 * generating the JPEG image (see @ref TJSAMP 743 * "Chrominance subsampling options".) 744 * 745 * @param jpegQual the image quality of the generated JPEG image (1 = worst, 746 * 100 = best) 747 * 748 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 749 * "flags" 750 * 751 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 752 * and #tjGetErrorCode().) 753 */ 754 DLLEXPORT int tjCompress2(tjhandle handle, const unsigned char *srcBuf, 755 int width, int pitch, int height, int pixelFormat, 756 unsigned char **jpegBuf, unsigned long *jpegSize, 757 int jpegSubsamp, int jpegQual, int flags); 758 759 760 /** 761 * Compress a YUV planar image into a JPEG image. 762 * 763 * @param handle a handle to a TurboJPEG compressor or transformer instance 764 * 765 * @param srcBuf pointer to an image buffer containing a YUV planar image to be 766 * compressed. The size of this buffer should match the value returned by 767 * #tjBufSizeYUV2() for the given image width, height, padding, and level of 768 * chrominance subsampling. The Y, U (Cb), and V (Cr) image planes should be 769 * stored sequentially in the source buffer (refer to @ref YUVnotes 770 * "YUV Image Format Notes".) 771 * 772 * @param width width (in pixels) of the source image. If the width is not an 773 * even multiple of the MCU block width (see #tjMCUWidth), then an intermediate 774 * buffer copy will be performed within TurboJPEG. 775 * 776 * @param pad the line padding used in the source image. For instance, if each 777 * line in each plane of the YUV image is padded to the nearest multiple of 4 778 * bytes, then <tt>pad</tt> should be set to 4. 779 * 780 * @param height height (in pixels) of the source image. If the height is not 781 * an even multiple of the MCU block height (see #tjMCUHeight), then an 782 * intermediate buffer copy will be performed within TurboJPEG. 783 * 784 * @param subsamp the level of chrominance subsampling used in the source 785 * image (see @ref TJSAMP "Chrominance subsampling options".) 786 * 787 * @param jpegBuf address of a pointer to an image buffer that will receive the 788 * JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to 789 * accommodate the size of the JPEG image. Thus, you can choose to: 790 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and 791 * let TurboJPEG grow the buffer as needed, 792 * -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer 793 * for you, or 794 * -# pre-allocate the buffer to a "worst case" size determined by calling 795 * #tjBufSize(). This should ensure that the buffer never has to be 796 * re-allocated (setting #TJFLAG_NOREALLOC guarantees that it won't be.) 797 * . 798 * If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your 799 * pre-allocated buffer. In any case, unless you have set #TJFLAG_NOREALLOC, 800 * you should always check <tt>*jpegBuf</tt> upon return from this function, as 801 * it may have changed. 802 * 803 * @param jpegSize pointer to an unsigned long variable that holds the size of 804 * the JPEG image buffer. If <tt>*jpegBuf</tt> points to a pre-allocated 805 * buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer. 806 * Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in 807 * bytes.) If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being 808 * reused from a previous call to one of the JPEG compression functions, then 809 * <tt>*jpegSize</tt> is ignored. 810 * 811 * @param jpegQual the image quality of the generated JPEG image (1 = worst, 812 * 100 = best) 813 * 814 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 815 * "flags" 816 * 817 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 818 * and #tjGetErrorCode().) 819 */ 820 DLLEXPORT int tjCompressFromYUV(tjhandle handle, const unsigned char *srcBuf, 821 int width, int pad, int height, int subsamp, 822 unsigned char **jpegBuf, 823 unsigned long *jpegSize, int jpegQual, 824 int flags); 825 826 827 /** 828 * Compress a set of Y, U (Cb), and V (Cr) image planes into a JPEG image. 829 * 830 * @param handle a handle to a TurboJPEG compressor or transformer instance 831 * 832 * @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes 833 * (or just a Y plane, if compressing a grayscale image) that contain a YUV 834 * image to be compressed. These planes can be contiguous or non-contiguous in 835 * memory. The size of each plane should match the value returned by 836 * #tjPlaneSizeYUV() for the given image width, height, strides, and level of 837 * chrominance subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" 838 * for more details. 839 * 840 * @param width width (in pixels) of the source image. If the width is not an 841 * even multiple of the MCU block width (see #tjMCUWidth), then an intermediate 842 * buffer copy will be performed within TurboJPEG. 843 * 844 * @param strides an array of integers, each specifying the number of bytes per 845 * line in the corresponding plane of the YUV source image. Setting the stride 846 * for any plane to 0 is the same as setting it to the plane width (see 847 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then 848 * the strides for all planes will be set to their respective plane widths. 849 * You can adjust the strides in order to specify an arbitrary amount of line 850 * padding in each plane or to create a JPEG image from a subregion of a larger 851 * YUV planar image. 852 * 853 * @param height height (in pixels) of the source image. If the height is not 854 * an even multiple of the MCU block height (see #tjMCUHeight), then an 855 * intermediate buffer copy will be performed within TurboJPEG. 856 * 857 * @param subsamp the level of chrominance subsampling used in the source 858 * image (see @ref TJSAMP "Chrominance subsampling options".) 859 * 860 * @param jpegBuf address of a pointer to an image buffer that will receive the 861 * JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to 862 * accommodate the size of the JPEG image. Thus, you can choose to: 863 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and 864 * let TurboJPEG grow the buffer as needed, 865 * -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer 866 * for you, or 867 * -# pre-allocate the buffer to a "worst case" size determined by calling 868 * #tjBufSize(). This should ensure that the buffer never has to be 869 * re-allocated (setting #TJFLAG_NOREALLOC guarantees that it won't be.) 870 * . 871 * If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your 872 * pre-allocated buffer. In any case, unless you have set #TJFLAG_NOREALLOC, 873 * you should always check <tt>*jpegBuf</tt> upon return from this function, as 874 * it may have changed. 875 * 876 * @param jpegSize pointer to an unsigned long variable that holds the size of 877 * the JPEG image buffer. If <tt>*jpegBuf</tt> points to a pre-allocated 878 * buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer. 879 * Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in 880 * bytes.) If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being 881 * reused from a previous call to one of the JPEG compression functions, then 882 * <tt>*jpegSize</tt> is ignored. 883 * 884 * @param jpegQual the image quality of the generated JPEG image (1 = worst, 885 * 100 = best) 886 * 887 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 888 * "flags" 889 * 890 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 891 * and #tjGetErrorCode().) 892 */ 893 DLLEXPORT int tjCompressFromYUVPlanes(tjhandle handle, 894 const unsigned char **srcPlanes, 895 int width, const int *strides, 896 int height, int subsamp, 897 unsigned char **jpegBuf, 898 unsigned long *jpegSize, int jpegQual, 899 int flags); 900 901 902 /** 903 * The maximum size of the buffer (in bytes) required to hold a JPEG image with 904 * the given parameters. The number of bytes returned by this function is 905 * larger than the size of the uncompressed source image. The reason for this 906 * is that the JPEG format uses 16-bit coefficients, and it is thus possible 907 * for a very high-quality JPEG image with very high-frequency content to 908 * expand rather than compress when converted to the JPEG format. Such images 909 * represent a very rare corner case, but since there is no way to predict the 910 * size of a JPEG image prior to compression, the corner case has to be 911 * handled. 912 * 913 * @param width width (in pixels) of the image 914 * 915 * @param height height (in pixels) of the image 916 * 917 * @param jpegSubsamp the level of chrominance subsampling to be used when 918 * generating the JPEG image (see @ref TJSAMP 919 * "Chrominance subsampling options".) 920 * 921 * @return the maximum size of the buffer (in bytes) required to hold the 922 * image, or -1 if the arguments are out of bounds. 923 */ 924 DLLEXPORT unsigned long tjBufSize(int width, int height, int jpegSubsamp); 925 926 927 /** 928 * The size of the buffer (in bytes) required to hold a YUV planar image with 929 * the given parameters. 930 * 931 * @param width width (in pixels) of the image 932 * 933 * @param pad the width of each line in each plane of the image is padded to 934 * the nearest multiple of this number of bytes (must be a power of 2.) 935 * 936 * @param height height (in pixels) of the image 937 * 938 * @param subsamp level of chrominance subsampling in the image (see 939 * @ref TJSAMP "Chrominance subsampling options".) 940 * 941 * @return the size of the buffer (in bytes) required to hold the image, or 942 * -1 if the arguments are out of bounds. 943 */ 944 DLLEXPORT unsigned long tjBufSizeYUV2(int width, int pad, int height, 945 int subsamp); 946 947 948 /** 949 * The size of the buffer (in bytes) required to hold a YUV image plane with 950 * the given parameters. 951 * 952 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr) 953 * 954 * @param width width (in pixels) of the YUV image. NOTE: this is the width of 955 * the whole image, not the plane width. 956 * 957 * @param stride bytes per line in the image plane. Setting this to 0 is the 958 * equivalent of setting it to the plane width. 959 * 960 * @param height height (in pixels) of the YUV image. NOTE: this is the height 961 * of the whole image, not the plane height. 962 * 963 * @param subsamp level of chrominance subsampling in the image (see 964 * @ref TJSAMP "Chrominance subsampling options".) 965 * 966 * @return the size of the buffer (in bytes) required to hold the YUV image 967 * plane, or -1 if the arguments are out of bounds. 968 */ 969 DLLEXPORT unsigned long tjPlaneSizeYUV(int componentID, int width, int stride, 970 int height, int subsamp); 971 972 973 /** 974 * The plane width of a YUV image plane with the given parameters. Refer to 975 * @ref YUVnotes "YUV Image Format Notes" for a description of plane width. 976 * 977 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr) 978 * 979 * @param width width (in pixels) of the YUV image 980 * 981 * @param subsamp level of chrominance subsampling in the image (see 982 * @ref TJSAMP "Chrominance subsampling options".) 983 * 984 * @return the plane width of a YUV image plane with the given parameters, or 985 * -1 if the arguments are out of bounds. 986 */ 987 DLLEXPORT int tjPlaneWidth(int componentID, int width, int subsamp); 988 989 990 /** 991 * The plane height of a YUV image plane with the given parameters. Refer to 992 * @ref YUVnotes "YUV Image Format Notes" for a description of plane height. 993 * 994 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr) 995 * 996 * @param height height (in pixels) of the YUV image 997 * 998 * @param subsamp level of chrominance subsampling in the image (see 999 * @ref TJSAMP "Chrominance subsampling options".) 1000 * 1001 * @return the plane height of a YUV image plane with the given parameters, or 1002 * -1 if the arguments are out of bounds. 1003 */ 1004 DLLEXPORT int tjPlaneHeight(int componentID, int height, int subsamp); 1005 1006 1007 /** 1008 * Encode an RGB or grayscale image into a YUV planar image. This function 1009 * uses the accelerated color conversion routines in the underlying 1010 * codec but does not execute any of the other steps in the JPEG compression 1011 * process. 1012 * 1013 * @param handle a handle to a TurboJPEG compressor or transformer instance 1014 * 1015 * @param srcBuf pointer to an image buffer containing RGB or grayscale pixels 1016 * to be encoded 1017 * 1018 * @param width width (in pixels) of the source image 1019 * 1020 * @param pitch bytes per line in the source image. Normally, this should be 1021 * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or 1022 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image 1023 * is padded to the nearest 32-bit boundary, as is the case for Windows 1024 * bitmaps. You can also be clever and use this parameter to skip lines, etc. 1025 * Setting this parameter to 0 is the equivalent of setting it to 1026 * <tt>width * #tjPixelSize[pixelFormat]</tt>. 1027 * 1028 * @param height height (in pixels) of the source image 1029 * 1030 * @param pixelFormat pixel format of the source image (see @ref TJPF 1031 * "Pixel formats".) 1032 * 1033 * @param dstBuf pointer to an image buffer that will receive the YUV image. 1034 * Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based 1035 * on the image width, height, padding, and level of chrominance subsampling. 1036 * The Y, U (Cb), and V (Cr) image planes will be stored sequentially in the 1037 * buffer (refer to @ref YUVnotes "YUV Image Format Notes".) 1038 * 1039 * @param pad the width of each line in each plane of the YUV image will be 1040 * padded to the nearest multiple of this number of bytes (must be a power of 1041 * 2.) To generate images suitable for X Video, <tt>pad</tt> should be set to 1042 * 4. 1043 * 1044 * @param subsamp the level of chrominance subsampling to be used when 1045 * generating the YUV image (see @ref TJSAMP 1046 * "Chrominance subsampling options".) To generate images suitable for X 1047 * Video, <tt>subsamp</tt> should be set to @ref TJSAMP_420. This produces an 1048 * image compatible with the I420 (AKA "YUV420P") format. 1049 * 1050 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1051 * "flags" 1052 * 1053 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 1054 * and #tjGetErrorCode().) 1055 */ 1056 DLLEXPORT int tjEncodeYUV3(tjhandle handle, const unsigned char *srcBuf, 1057 int width, int pitch, int height, int pixelFormat, 1058 unsigned char *dstBuf, int pad, int subsamp, 1059 int flags); 1060 1061 1062 /** 1063 * Encode an RGB or grayscale image into separate Y, U (Cb), and V (Cr) image 1064 * planes. This function uses the accelerated color conversion routines in the 1065 * underlying codec but does not execute any of the other steps in the JPEG 1066 * compression process. 1067 * 1068 * @param handle a handle to a TurboJPEG compressor or transformer instance 1069 * 1070 * @param srcBuf pointer to an image buffer containing RGB or grayscale pixels 1071 * to be encoded 1072 * 1073 * @param width width (in pixels) of the source image 1074 * 1075 * @param pitch bytes per line in the source image. Normally, this should be 1076 * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or 1077 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image 1078 * is padded to the nearest 32-bit boundary, as is the case for Windows 1079 * bitmaps. You can also be clever and use this parameter to skip lines, etc. 1080 * Setting this parameter to 0 is the equivalent of setting it to 1081 * <tt>width * #tjPixelSize[pixelFormat]</tt>. 1082 * 1083 * @param height height (in pixels) of the source image 1084 * 1085 * @param pixelFormat pixel format of the source image (see @ref TJPF 1086 * "Pixel formats".) 1087 * 1088 * @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes 1089 * (or just a Y plane, if generating a grayscale image) that will receive the 1090 * encoded image. These planes can be contiguous or non-contiguous in memory. 1091 * Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based 1092 * on the image width, height, strides, and level of chrominance subsampling. 1093 * Refer to @ref YUVnotes "YUV Image Format Notes" for more details. 1094 * 1095 * @param strides an array of integers, each specifying the number of bytes per 1096 * line in the corresponding plane of the output image. Setting the stride for 1097 * any plane to 0 is the same as setting it to the plane width (see 1098 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then 1099 * the strides for all planes will be set to their respective plane widths. 1100 * You can adjust the strides in order to add an arbitrary amount of line 1101 * padding to each plane or to encode an RGB or grayscale image into a 1102 * subregion of a larger YUV planar image. 1103 * 1104 * @param subsamp the level of chrominance subsampling to be used when 1105 * generating the YUV image (see @ref TJSAMP 1106 * "Chrominance subsampling options".) To generate images suitable for X 1107 * Video, <tt>subsamp</tt> should be set to @ref TJSAMP_420. This produces an 1108 * image compatible with the I420 (AKA "YUV420P") format. 1109 * 1110 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1111 * "flags" 1112 * 1113 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 1114 * and #tjGetErrorCode().) 1115 */ 1116 DLLEXPORT int tjEncodeYUVPlanes(tjhandle handle, const unsigned char *srcBuf, 1117 int width, int pitch, int height, 1118 int pixelFormat, unsigned char **dstPlanes, 1119 int *strides, int subsamp, int flags); 1120 1121 1122 /** 1123 * Create a TurboJPEG decompressor instance. 1124 * 1125 * @return a handle to the newly-created instance, or NULL if an error 1126 * occurred (see #tjGetErrorStr2().) 1127 */ 1128 DLLEXPORT tjhandle tjInitDecompress(void); 1129 1130 1131 /** 1132 * Retrieve information about a JPEG image without decompressing it. 1133 * 1134 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1135 * 1136 * @param jpegBuf pointer to a buffer containing a JPEG image 1137 * 1138 * @param jpegSize size of the JPEG image (in bytes) 1139 * 1140 * @param width pointer to an integer variable that will receive the width (in 1141 * pixels) of the JPEG image 1142 * 1143 * @param height pointer to an integer variable that will receive the height 1144 * (in pixels) of the JPEG image 1145 * 1146 * @param jpegSubsamp pointer to an integer variable that will receive the 1147 * level of chrominance subsampling used when the JPEG image was compressed 1148 * (see @ref TJSAMP "Chrominance subsampling options".) 1149 * 1150 * @param jpegColorspace pointer to an integer variable that will receive one 1151 * of the JPEG colorspace constants, indicating the colorspace of the JPEG 1152 * image (see @ref TJCS "JPEG colorspaces".) 1153 * 1154 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 1155 * and #tjGetErrorCode().) 1156 */ 1157 DLLEXPORT int tjDecompressHeader3(tjhandle handle, 1158 const unsigned char *jpegBuf, 1159 unsigned long jpegSize, int *width, 1160 int *height, int *jpegSubsamp, 1161 int *jpegColorspace); 1162 1163 1164 /** 1165 * Returns a list of fractional scaling factors that the JPEG decompressor in 1166 * this implementation of TurboJPEG supports. 1167 * 1168 * @param numscalingfactors pointer to an integer variable that will receive 1169 * the number of elements in the list 1170 * 1171 * @return a pointer to a list of fractional scaling factors, or NULL if an 1172 * error is encountered (see #tjGetErrorStr2().) 1173 */ 1174 DLLEXPORT tjscalingfactor *tjGetScalingFactors(int *numscalingfactors); 1175 1176 1177 /** 1178 * Decompress a JPEG image to an RGB, grayscale, or CMYK image. 1179 * 1180 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1181 * 1182 * @param jpegBuf pointer to a buffer containing the JPEG image to decompress 1183 * 1184 * @param jpegSize size of the JPEG image (in bytes) 1185 * 1186 * @param dstBuf pointer to an image buffer that will receive the decompressed 1187 * image. This buffer should normally be <tt>pitch * scaledHeight</tt> bytes 1188 * in size, where <tt>scaledHeight</tt> can be determined by calling 1189 * #TJSCALED() with the JPEG image height and one of the scaling factors 1190 * returned by #tjGetScalingFactors(). The <tt>dstBuf</tt> pointer may also be 1191 * used to decompress into a specific region of a larger buffer. 1192 * 1193 * @param width desired width (in pixels) of the destination image. If this is 1194 * different than the width of the JPEG image being decompressed, then 1195 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1196 * possible image that will fit within the desired width. If <tt>width</tt> is 1197 * set to 0, then only the height will be considered when determining the 1198 * scaled image size. 1199 * 1200 * @param pitch bytes per line in the destination image. Normally, this is 1201 * <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt> if the decompressed image 1202 * is unpadded, else <tt>#TJPAD(scaledWidth * #tjPixelSize[pixelFormat])</tt> 1203 * if each line of the decompressed image is padded to the nearest 32-bit 1204 * boundary, as is the case for Windows bitmaps. (NOTE: <tt>scaledWidth</tt> 1205 * can be determined by calling #TJSCALED() with the JPEG image width and one 1206 * of the scaling factors returned by #tjGetScalingFactors().) You can also be 1207 * clever and use the pitch parameter to skip lines, etc. Setting this 1208 * parameter to 0 is the equivalent of setting it to 1209 * <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt>. 1210 * 1211 * @param height desired height (in pixels) of the destination image. If this 1212 * is different than the height of the JPEG image being decompressed, then 1213 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1214 * possible image that will fit within the desired height. If <tt>height</tt> 1215 * is set to 0, then only the width will be considered when determining the 1216 * scaled image size. 1217 * 1218 * @param pixelFormat pixel format of the destination image (see @ref 1219 * TJPF "Pixel formats".) 1220 * 1221 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1222 * "flags" 1223 * 1224 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 1225 * and #tjGetErrorCode().) 1226 */ 1227 DLLEXPORT int tjDecompress2(tjhandle handle, const unsigned char *jpegBuf, 1228 unsigned long jpegSize, unsigned char *dstBuf, 1229 int width, int pitch, int height, int pixelFormat, 1230 int flags); 1231 1232 1233 /** 1234 * Decompress a JPEG image to a YUV planar image. This function performs JPEG 1235 * decompression but leaves out the color conversion step, so a planar YUV 1236 * image is generated instead of an RGB image. 1237 * 1238 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1239 * 1240 * @param jpegBuf pointer to a buffer containing the JPEG image to decompress 1241 * 1242 * @param jpegSize size of the JPEG image (in bytes) 1243 * 1244 * @param dstBuf pointer to an image buffer that will receive the YUV image. 1245 * Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based 1246 * on the image width, height, padding, and level of subsampling. The Y, 1247 * U (Cb), and V (Cr) image planes will be stored sequentially in the buffer 1248 * (refer to @ref YUVnotes "YUV Image Format Notes".) 1249 * 1250 * @param width desired width (in pixels) of the YUV image. If this is 1251 * different than the width of the JPEG image being decompressed, then 1252 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1253 * possible image that will fit within the desired width. If <tt>width</tt> is 1254 * set to 0, then only the height will be considered when determining the 1255 * scaled image size. If the scaled width is not an even multiple of the MCU 1256 * block width (see #tjMCUWidth), then an intermediate buffer copy will be 1257 * performed within TurboJPEG. 1258 * 1259 * @param pad the width of each line in each plane of the YUV image will be 1260 * padded to the nearest multiple of this number of bytes (must be a power of 1261 * 2.) To generate images suitable for X Video, <tt>pad</tt> should be set to 1262 * 4. 1263 * 1264 * @param height desired height (in pixels) of the YUV image. If this is 1265 * different than the height of the JPEG image being decompressed, then 1266 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1267 * possible image that will fit within the desired height. If <tt>height</tt> 1268 * is set to 0, then only the width will be considered when determining the 1269 * scaled image size. If the scaled height is not an even multiple of the MCU 1270 * block height (see #tjMCUHeight), then an intermediate buffer copy will be 1271 * performed within TurboJPEG. 1272 * 1273 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1274 * "flags" 1275 * 1276 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 1277 * and #tjGetErrorCode().) 1278 */ 1279 DLLEXPORT int tjDecompressToYUV2(tjhandle handle, const unsigned char *jpegBuf, 1280 unsigned long jpegSize, unsigned char *dstBuf, 1281 int width, int pad, int height, int flags); 1282 1283 1284 /** 1285 * Decompress a JPEG image into separate Y, U (Cb), and V (Cr) image 1286 * planes. This function performs JPEG decompression but leaves out the color 1287 * conversion step, so a planar YUV image is generated instead of an RGB image. 1288 * 1289 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1290 * 1291 * @param jpegBuf pointer to a buffer containing the JPEG image to decompress 1292 * 1293 * @param jpegSize size of the JPEG image (in bytes) 1294 * 1295 * @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes 1296 * (or just a Y plane, if decompressing a grayscale image) that will receive 1297 * the YUV image. These planes can be contiguous or non-contiguous in memory. 1298 * Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based 1299 * on the scaled image width, scaled image height, strides, and level of 1300 * chrominance subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" 1301 * for more details. 1302 * 1303 * @param width desired width (in pixels) of the YUV image. If this is 1304 * different than the width of the JPEG image being decompressed, then 1305 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1306 * possible image that will fit within the desired width. If <tt>width</tt> is 1307 * set to 0, then only the height will be considered when determining the 1308 * scaled image size. If the scaled width is not an even multiple of the MCU 1309 * block width (see #tjMCUWidth), then an intermediate buffer copy will be 1310 * performed within TurboJPEG. 1311 * 1312 * @param strides an array of integers, each specifying the number of bytes per 1313 * line in the corresponding plane of the output image. Setting the stride for 1314 * any plane to 0 is the same as setting it to the scaled plane width (see 1315 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then 1316 * the strides for all planes will be set to their respective scaled plane 1317 * widths. You can adjust the strides in order to add an arbitrary amount of 1318 * line padding to each plane or to decompress the JPEG image into a subregion 1319 * of a larger YUV planar image. 1320 * 1321 * @param height desired height (in pixels) of the YUV image. If this is 1322 * different than the height of the JPEG image being decompressed, then 1323 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1324 * possible image that will fit within the desired height. If <tt>height</tt> 1325 * is set to 0, then only the width will be considered when determining the 1326 * scaled image size. If the scaled height is not an even multiple of the MCU 1327 * block height (see #tjMCUHeight), then an intermediate buffer copy will be 1328 * performed within TurboJPEG. 1329 * 1330 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1331 * "flags" 1332 * 1333 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 1334 * and #tjGetErrorCode().) 1335 */ 1336 DLLEXPORT int tjDecompressToYUVPlanes(tjhandle handle, 1337 const unsigned char *jpegBuf, 1338 unsigned long jpegSize, 1339 unsigned char **dstPlanes, int width, 1340 int *strides, int height, int flags); 1341 1342 1343 /** 1344 * Decode a YUV planar image into an RGB or grayscale image. This function 1345 * uses the accelerated color conversion routines in the underlying 1346 * codec but does not execute any of the other steps in the JPEG decompression 1347 * process. 1348 * 1349 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1350 * 1351 * @param srcBuf pointer to an image buffer containing a YUV planar image to be 1352 * decoded. The size of this buffer should match the value returned by 1353 * #tjBufSizeYUV2() for the given image width, height, padding, and level of 1354 * chrominance subsampling. The Y, U (Cb), and V (Cr) image planes should be 1355 * stored sequentially in the source buffer (refer to @ref YUVnotes 1356 * "YUV Image Format Notes".) 1357 * 1358 * @param pad Use this parameter to specify that the width of each line in each 1359 * plane of the YUV source image is padded to the nearest multiple of this 1360 * number of bytes (must be a power of 2.) 1361 * 1362 * @param subsamp the level of chrominance subsampling used in the YUV source 1363 * image (see @ref TJSAMP "Chrominance subsampling options".) 1364 * 1365 * @param dstBuf pointer to an image buffer that will receive the decoded 1366 * image. This buffer should normally be <tt>pitch * height</tt> bytes in 1367 * size, but the <tt>dstBuf</tt> pointer can also be used to decode into a 1368 * specific region of a larger buffer. 1369 * 1370 * @param width width (in pixels) of the source and destination images 1371 * 1372 * @param pitch bytes per line in the destination image. Normally, this should 1373 * be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is 1374 * unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line 1375 * of the destination image should be padded to the nearest 32-bit boundary, as 1376 * is the case for Windows bitmaps. You can also be clever and use the pitch 1377 * parameter to skip lines, etc. Setting this parameter to 0 is the equivalent 1378 * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>. 1379 * 1380 * @param height height (in pixels) of the source and destination images 1381 * 1382 * @param pixelFormat pixel format of the destination image (see @ref TJPF 1383 * "Pixel formats".) 1384 * 1385 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1386 * "flags" 1387 * 1388 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 1389 * and #tjGetErrorCode().) 1390 */ 1391 DLLEXPORT int tjDecodeYUV(tjhandle handle, const unsigned char *srcBuf, 1392 int pad, int subsamp, unsigned char *dstBuf, 1393 int width, int pitch, int height, int pixelFormat, 1394 int flags); 1395 1396 1397 /** 1398 * Decode a set of Y, U (Cb), and V (Cr) image planes into an RGB or grayscale 1399 * image. This function uses the accelerated color conversion routines in the 1400 * underlying codec but does not execute any of the other steps in the JPEG 1401 * decompression process. 1402 * 1403 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1404 * 1405 * @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes 1406 * (or just a Y plane, if decoding a grayscale image) that contain a YUV image 1407 * to be decoded. These planes can be contiguous or non-contiguous in memory. 1408 * The size of each plane should match the value returned by #tjPlaneSizeYUV() 1409 * for the given image width, height, strides, and level of chrominance 1410 * subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" for more 1411 * details. 1412 * 1413 * @param strides an array of integers, each specifying the number of bytes per 1414 * line in the corresponding plane of the YUV source image. Setting the stride 1415 * for any plane to 0 is the same as setting it to the plane width (see 1416 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then 1417 * the strides for all planes will be set to their respective plane widths. 1418 * You can adjust the strides in order to specify an arbitrary amount of line 1419 * padding in each plane or to decode a subregion of a larger YUV planar image. 1420 * 1421 * @param subsamp the level of chrominance subsampling used in the YUV source 1422 * image (see @ref TJSAMP "Chrominance subsampling options".) 1423 * 1424 * @param dstBuf pointer to an image buffer that will receive the decoded 1425 * image. This buffer should normally be <tt>pitch * height</tt> bytes in 1426 * size, but the <tt>dstBuf</tt> pointer can also be used to decode into a 1427 * specific region of a larger buffer. 1428 * 1429 * @param width width (in pixels) of the source and destination images 1430 * 1431 * @param pitch bytes per line in the destination image. Normally, this should 1432 * be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is 1433 * unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line 1434 * of the destination image should be padded to the nearest 32-bit boundary, as 1435 * is the case for Windows bitmaps. You can also be clever and use the pitch 1436 * parameter to skip lines, etc. Setting this parameter to 0 is the equivalent 1437 * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>. 1438 * 1439 * @param height height (in pixels) of the source and destination images 1440 * 1441 * @param pixelFormat pixel format of the destination image (see @ref TJPF 1442 * "Pixel formats".) 1443 * 1444 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1445 * "flags" 1446 * 1447 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 1448 * and #tjGetErrorCode().) 1449 */ 1450 DLLEXPORT int tjDecodeYUVPlanes(tjhandle handle, 1451 const unsigned char **srcPlanes, 1452 const int *strides, int subsamp, 1453 unsigned char *dstBuf, int width, int pitch, 1454 int height, int pixelFormat, int flags); 1455 1456 1457 /** 1458 * Create a new TurboJPEG transformer instance. 1459 * 1460 * @return a handle to the newly-created instance, or NULL if an error 1461 * occurred (see #tjGetErrorStr2().) 1462 */ 1463 DLLEXPORT tjhandle tjInitTransform(void); 1464 1465 1466 /** 1467 * Losslessly transform a JPEG image into another JPEG image. Lossless 1468 * transforms work by moving the raw DCT coefficients from one JPEG image 1469 * structure to another without altering the values of the coefficients. While 1470 * this is typically faster than decompressing the image, transforming it, and 1471 * re-compressing it, lossless transforms are not free. Each lossless 1472 * transform requires reading and performing Huffman decoding on all of the 1473 * coefficients in the source image, regardless of the size of the destination 1474 * image. Thus, this function provides a means of generating multiple 1475 * transformed images from the same source or applying multiple 1476 * transformations simultaneously, in order to eliminate the need to read the 1477 * source coefficients multiple times. 1478 * 1479 * @param handle a handle to a TurboJPEG transformer instance 1480 * 1481 * @param jpegBuf pointer to a buffer containing the JPEG source image to 1482 * transform 1483 * 1484 * @param jpegSize size of the JPEG source image (in bytes) 1485 * 1486 * @param n the number of transformed JPEG images to generate 1487 * 1488 * @param dstBufs pointer to an array of n image buffers. <tt>dstBufs[i]</tt> 1489 * will receive a JPEG image that has been transformed using the parameters in 1490 * <tt>transforms[i]</tt>. TurboJPEG has the ability to reallocate the JPEG 1491 * buffer to accommodate the size of the JPEG image. Thus, you can choose to: 1492 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and 1493 * let TurboJPEG grow the buffer as needed, 1494 * -# set <tt>dstBufs[i]</tt> to NULL to tell TurboJPEG to allocate the buffer 1495 * for you, or 1496 * -# pre-allocate the buffer to a "worst case" size determined by calling 1497 * #tjBufSize() with the transformed or cropped width and height. Under normal 1498 * circumstances, this should ensure that the buffer never has to be 1499 * re-allocated (setting #TJFLAG_NOREALLOC guarantees that it won't be.) Note, 1500 * however, that there are some rare cases (such as transforming images with a 1501 * large amount of embedded EXIF or ICC profile data) in which the output image 1502 * will be larger than the worst-case size, and #TJFLAG_NOREALLOC cannot be 1503 * used in those cases. 1504 * . 1505 * If you choose option 1, <tt>dstSizes[i]</tt> should be set to the size of 1506 * your pre-allocated buffer. In any case, unless you have set 1507 * #TJFLAG_NOREALLOC, you should always check <tt>dstBufs[i]</tt> upon return 1508 * from this function, as it may have changed. 1509 * 1510 * @param dstSizes pointer to an array of n unsigned long variables that will 1511 * receive the actual sizes (in bytes) of each transformed JPEG image. If 1512 * <tt>dstBufs[i]</tt> points to a pre-allocated buffer, then 1513 * <tt>dstSizes[i]</tt> should be set to the size of the buffer. Upon return, 1514 * <tt>dstSizes[i]</tt> will contain the size of the JPEG image (in bytes.) 1515 * 1516 * @param transforms pointer to an array of n #tjtransform structures, each of 1517 * which specifies the transform parameters and/or cropping region for the 1518 * corresponding transformed output image. 1519 * 1520 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1521 * "flags" 1522 * 1523 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2() 1524 * and #tjGetErrorCode().) 1525 */ 1526 DLLEXPORT int tjTransform(tjhandle handle, const unsigned char *jpegBuf, 1527 unsigned long jpegSize, int n, 1528 unsigned char **dstBufs, unsigned long *dstSizes, 1529 tjtransform *transforms, int flags); 1530 1531 1532 /** 1533 * Destroy a TurboJPEG compressor, decompressor, or transformer instance. 1534 * 1535 * @param handle a handle to a TurboJPEG compressor, decompressor or 1536 * transformer instance 1537 * 1538 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2().) 1539 */ 1540 DLLEXPORT int tjDestroy(tjhandle handle); 1541 1542 1543 /** 1544 * Allocate an image buffer for use with TurboJPEG. You should always use 1545 * this function to allocate the JPEG destination buffer(s) for the compression 1546 * and transform functions unless you are disabling automatic buffer 1547 * (re)allocation (by setting #TJFLAG_NOREALLOC.) 1548 * 1549 * @param bytes the number of bytes to allocate 1550 * 1551 * @return a pointer to a newly-allocated buffer with the specified number of 1552 * bytes. 1553 * 1554 * @sa tjFree() 1555 */ 1556 DLLEXPORT unsigned char *tjAlloc(int bytes); 1557 1558 1559 /** 1560 * Load an uncompressed image from disk into memory. 1561 * 1562 * @param filename name of a file containing an uncompressed image in Windows 1563 * BMP or PBMPLUS (PPM/PGM) format 1564 * 1565 * @param width pointer to an integer variable that will receive the width (in 1566 * pixels) of the uncompressed image 1567 * 1568 * @param align row alignment of the image buffer to be returned (must be a 1569 * power of 2.) For instance, setting this parameter to 4 will cause all rows 1570 * in the image buffer to be padded to the nearest 32-bit boundary, and setting 1571 * this parameter to 1 will cause all rows in the image buffer to be unpadded. 1572 * 1573 * @param height pointer to an integer variable that will receive the height 1574 * (in pixels) of the uncompressed image 1575 * 1576 * @param pixelFormat pointer to an integer variable that specifies or will 1577 * receive the pixel format of the uncompressed image buffer. The behavior of 1578 * #tjLoadImage() will vary depending on the value of <tt>*pixelFormat</tt> 1579 * passed to the function: 1580 * - @ref TJPF_UNKNOWN : The uncompressed image buffer returned by the function 1581 * will use the most optimal pixel format for the file type, and 1582 * <tt>*pixelFormat</tt> will contain the ID of this pixel format upon 1583 * successful return from the function. 1584 * - @ref TJPF_GRAY : Only PGM files and 8-bit BMP files with a grayscale 1585 * colormap can be loaded. 1586 * - @ref TJPF_CMYK : The RGB or grayscale pixels stored in the file will be 1587 * converted using a quick & dirty algorithm that is suitable only for testing 1588 * purposes (proper conversion between CMYK and other formats requires a color 1589 * management system.) 1590 * - Other @ref TJPF "pixel formats" : The uncompressed image buffer will use 1591 * the specified pixel format, and pixel format conversion will be performed if 1592 * necessary. 1593 * 1594 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP 1595 * "flags". 1596 * 1597 * @return a pointer to a newly-allocated buffer containing the uncompressed 1598 * image, converted to the chosen pixel format and with the chosen row 1599 * alignment, or NULL if an error occurred (see #tjGetErrorStr2().) This 1600 * buffer should be freed using #tjFree(). 1601 */ 1602 DLLEXPORT unsigned char *tjLoadImage(const char *filename, int *width, 1603 int align, int *height, int *pixelFormat, 1604 int flags); 1605 1606 1607 /** 1608 * Save an uncompressed image from memory to disk. 1609 * 1610 * @param filename name of a file to which to save the uncompressed image. 1611 * The image will be stored in Windows BMP or PBMPLUS (PPM/PGM) format, 1612 * depending on the file extension. 1613 * 1614 * @param buffer pointer to an image buffer containing RGB, grayscale, or 1615 * CMYK pixels to be saved 1616 * 1617 * @param width width (in pixels) of the uncompressed image 1618 * 1619 * @param pitch bytes per line in the image buffer. Setting this parameter to 1620 * 0 is the equivalent of setting it to 1621 * <tt>width * #tjPixelSize[pixelFormat]</tt>. 1622 * 1623 * @param height height (in pixels) of the uncompressed image 1624 * 1625 * @param pixelFormat pixel format of the image buffer (see @ref TJPF 1626 * "Pixel formats".) If this parameter is set to @ref TJPF_GRAY, then the 1627 * image will be stored in PGM or 8-bit (indexed color) BMP format. Otherwise, 1628 * the image will be stored in PPM or 24-bit BMP format. If this parameter 1629 * is set to @ref TJPF_CMYK, then the CMYK pixels will be converted to RGB 1630 * using a quick & dirty algorithm that is suitable only for testing (proper 1631 * conversion between CMYK and other formats requires a color management 1632 * system.) 1633 * 1634 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP 1635 * "flags". 1636 * 1637 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2().) 1638 */ 1639 DLLEXPORT int tjSaveImage(const char *filename, unsigned char *buffer, 1640 int width, int pitch, int height, int pixelFormat, 1641 int flags); 1642 1643 1644 /** 1645 * Free an image buffer previously allocated by TurboJPEG. You should always 1646 * use this function to free JPEG destination buffer(s) that were automatically 1647 * (re)allocated by the compression and transform functions or that were 1648 * manually allocated using #tjAlloc(). 1649 * 1650 * @param buffer address of the buffer to free. If the address is NULL, then 1651 * this function has no effect. 1652 * 1653 * @sa tjAlloc() 1654 */ 1655 DLLEXPORT void tjFree(unsigned char *buffer); 1656 1657 1658 /** 1659 * Returns a descriptive error message explaining why the last command failed. 1660 * 1661 * @param handle a handle to a TurboJPEG compressor, decompressor, or 1662 * transformer instance, or NULL if the error was generated by a global 1663 * function (but note that retrieving the error message for a global function 1664 * is thread-safe only on platforms that support thread-local storage.) 1665 * 1666 * @return a descriptive error message explaining why the last command failed. 1667 */ 1668 DLLEXPORT char *tjGetErrorStr2(tjhandle handle); 1669 1670 1671 /** 1672 * Returns a code indicating the severity of the last error. See 1673 * @ref TJERR "Error codes". 1674 * 1675 * @param handle a handle to a TurboJPEG compressor, decompressor or 1676 * transformer instance 1677 * 1678 * @return a code indicating the severity of the last error. See 1679 * @ref TJERR "Error codes". 1680 */ 1681 DLLEXPORT int tjGetErrorCode(tjhandle handle); 1682 1683 1684 /* Deprecated functions and macros */ 1685 #define TJFLAG_FORCEMMX 8 1686 #define TJFLAG_FORCESSE 16 1687 #define TJFLAG_FORCESSE2 32 1688 #define TJFLAG_FORCESSE3 128 1689 1690 1691 /* Backward compatibility functions and macros (nothing to see here) */ 1692 #define NUMSUBOPT TJ_NUMSAMP 1693 #define TJ_444 TJSAMP_444 1694 #define TJ_422 TJSAMP_422 1695 #define TJ_420 TJSAMP_420 1696 #define TJ_411 TJSAMP_420 1697 #define TJ_GRAYSCALE TJSAMP_GRAY 1698 1699 #define TJ_BGR 1 1700 #define TJ_BOTTOMUP TJFLAG_BOTTOMUP 1701 #define TJ_FORCEMMX TJFLAG_FORCEMMX 1702 #define TJ_FORCESSE TJFLAG_FORCESSE 1703 #define TJ_FORCESSE2 TJFLAG_FORCESSE2 1704 #define TJ_ALPHAFIRST 64 1705 #define TJ_FORCESSE3 TJFLAG_FORCESSE3 1706 #define TJ_FASTUPSAMPLE TJFLAG_FASTUPSAMPLE 1707 #define TJ_YUV 512 1708 1709 DLLEXPORT unsigned long TJBUFSIZE(int width, int height); 1710 1711 DLLEXPORT unsigned long TJBUFSIZEYUV(int width, int height, int jpegSubsamp); 1712 1713 DLLEXPORT unsigned long tjBufSizeYUV(int width, int height, int subsamp); 1714 1715 DLLEXPORT int tjCompress(tjhandle handle, unsigned char *srcBuf, int width, 1716 int pitch, int height, int pixelSize, 1717 unsigned char *dstBuf, unsigned long *compressedSize, 1718 int jpegSubsamp, int jpegQual, int flags); 1719 1720 DLLEXPORT int tjEncodeYUV(tjhandle handle, unsigned char *srcBuf, int width, 1721 int pitch, int height, int pixelSize, 1722 unsigned char *dstBuf, int subsamp, int flags); 1723 1724 DLLEXPORT int tjEncodeYUV2(tjhandle handle, unsigned char *srcBuf, int width, 1725 int pitch, int height, int pixelFormat, 1726 unsigned char *dstBuf, int subsamp, int flags); 1727 1728 DLLEXPORT int tjDecompressHeader(tjhandle handle, unsigned char *jpegBuf, 1729 unsigned long jpegSize, int *width, 1730 int *height); 1731 1732 DLLEXPORT int tjDecompressHeader2(tjhandle handle, unsigned char *jpegBuf, 1733 unsigned long jpegSize, int *width, 1734 int *height, int *jpegSubsamp); 1735 1736 DLLEXPORT int tjDecompress(tjhandle handle, unsigned char *jpegBuf, 1737 unsigned long jpegSize, unsigned char *dstBuf, 1738 int width, int pitch, int height, int pixelSize, 1739 int flags); 1740 1741 DLLEXPORT int tjDecompressToYUV(tjhandle handle, unsigned char *jpegBuf, 1742 unsigned long jpegSize, unsigned char *dstBuf, 1743 int flags); 1744 1745 DLLEXPORT char *tjGetErrorStr(void); 1746 1747 1748 /** 1749 * @} 1750 */ 1751 1752 #ifdef __cplusplus 1753 } 1754 #endif 1755 1756 #endif 1757