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