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 */ 92enum TJSAMP 93{ 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 */ 144static 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 */ 155static 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 */ 166enum TJPF 167{ 168 /** 169 * RGB pixel format. The red, green, and blue components in the image are 170 * stored in 3-byte pixels in the order R, G, B from lowest to highest byte 171 * address within each pixel. 172 */ 173 TJPF_RGB=0, 174 /** 175 * BGR pixel format. The red, green, and blue components in the image are 176 * stored in 3-byte pixels in the order B, G, R from lowest to highest byte 177 * address within each pixel. 178 */ 179 TJPF_BGR, 180 /** 181 * RGBX pixel format. The red, green, and blue components in the image are 182 * stored in 4-byte pixels in the order R, G, B from lowest to highest byte 183 * address within each pixel. The X component is ignored when compressing 184 * and undefined when decompressing. 185 */ 186 TJPF_RGBX, 187 /** 188 * BGRX pixel format. The red, green, and blue components in the image are 189 * stored in 4-byte pixels in the order B, G, R from lowest to highest byte 190 * address within each pixel. The X component is ignored when compressing 191 * and undefined when decompressing. 192 */ 193 TJPF_BGRX, 194 /** 195 * XBGR pixel format. The red, green, and blue components in the image are 196 * stored in 4-byte pixels in the order R, G, B from highest to lowest byte 197 * address within each pixel. The X component is ignored when compressing 198 * and undefined when decompressing. 199 */ 200 TJPF_XBGR, 201 /** 202 * XRGB pixel format. The red, green, and blue components in the image are 203 * stored in 4-byte pixels in the order B, G, R from highest to lowest byte 204 * address within each pixel. The X component is ignored when compressing 205 * and undefined when decompressing. 206 */ 207 TJPF_XRGB, 208 /** 209 * Grayscale pixel format. Each 1-byte pixel represents a luminance 210 * (brightness) level from 0 to 255. 211 */ 212 TJPF_GRAY, 213 /** 214 * RGBA pixel format. This is the same as @ref TJPF_RGBX, except that when 215 * decompressing, the X component is guaranteed to be 0xFF, which can be 216 * interpreted as an opaque alpha channel. 217 */ 218 TJPF_RGBA, 219 /** 220 * BGRA pixel format. This is the same as @ref TJPF_BGRX, except that when 221 * decompressing, the X component is guaranteed to be 0xFF, which can be 222 * interpreted as an opaque alpha channel. 223 */ 224 TJPF_BGRA, 225 /** 226 * ABGR pixel format. This is the same as @ref TJPF_XBGR, except that when 227 * decompressing, the X component is guaranteed to be 0xFF, which can be 228 * interpreted as an opaque alpha channel. 229 */ 230 TJPF_ABGR, 231 /** 232 * ARGB pixel format. This is the same as @ref TJPF_XRGB, except that when 233 * decompressing, the X component is guaranteed to be 0xFF, which can be 234 * interpreted as an opaque alpha channel. 235 */ 236 TJPF_ARGB, 237 /** 238 * CMYK pixel format. Unlike RGB, which is an additive color model used 239 * primarily for display, CMYK (Cyan/Magenta/Yellow/Key) is a subtractive 240 * color model used primarily for printing. In the CMYK color model, the 241 * value of each color component typically corresponds to an amount of cyan, 242 * magenta, yellow, or black ink that is applied to a white background. In 243 * order to convert between CMYK and RGB, it is necessary to use a color 244 * management system (CMS.) A CMS will attempt to map colors within the 245 * printer's gamut to perceptually similar colors in the display's gamut and 246 * vice versa, but the mapping is typically not 1:1 or reversible, nor can it 247 * be defined with a simple formula. Thus, such a conversion is out of scope 248 * for a codec library. However, the TurboJPEG API allows for compressing 249 * CMYK pixels into a YCCK JPEG image (see #TJCS_YCCK) and decompressing YCCK 250 * JPEG images into CMYK pixels. 251 */ 252 TJPF_CMYK 253}; 254 255 256/** 257 * Red offset (in bytes) for a given pixel format. This specifies the number 258 * of bytes that the red component is offset from the start of the pixel. For 259 * instance, if a pixel of format TJ_BGRX is stored in <tt>char pixel[]</tt>, 260 * then the red component will be <tt>pixel[tjRedOffset[TJ_BGRX]]</tt>. 261 */ 262static const int tjRedOffset[TJ_NUMPF] = {0, 2, 0, 2, 3, 1, 0, 0, 2, 3, 1, -1}; 263/** 264 * Green offset (in bytes) for a given pixel format. This specifies the number 265 * of bytes that the green component is offset from the start of the pixel. 266 * For instance, if a pixel of format TJ_BGRX is stored in 267 * <tt>char pixel[]</tt>, then the green component will be 268 * <tt>pixel[tjGreenOffset[TJ_BGRX]]</tt>. 269 */ 270static const int tjGreenOffset[TJ_NUMPF] = {1, 1, 1, 1, 2, 2, 0, 1, 1, 2, 2, -1}; 271/** 272 * Blue offset (in bytes) for a given pixel format. This specifies the number 273 * of bytes that the Blue component is offset from the start of the pixel. For 274 * instance, if a pixel of format TJ_BGRX is stored in <tt>char pixel[]</tt>, 275 * then the blue component will be <tt>pixel[tjBlueOffset[TJ_BGRX]]</tt>. 276 */ 277static const int tjBlueOffset[TJ_NUMPF] = {2, 0, 2, 0, 1, 3, 0, 2, 0, 1, 3, -1}; 278/** 279 * Pixel size (in bytes) for a given pixel format. 280 */ 281static const int tjPixelSize[TJ_NUMPF] = {3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 4, 4}; 282 283 284/** 285 * The number of JPEG colorspaces 286 */ 287#define TJ_NUMCS 5 288 289/** 290 * JPEG colorspaces 291 */ 292enum TJCS 293{ 294 /** 295 * RGB colorspace. When compressing the JPEG image, the R, G, and B 296 * components in the source image are reordered into image planes, but no 297 * colorspace conversion or subsampling is performed. RGB JPEG images can be 298 * decompressed to any of the extended RGB pixel formats or grayscale, but 299 * they cannot be decompressed to YUV images. 300 */ 301 TJCS_RGB=0, 302 /** 303 * YCbCr colorspace. YCbCr is not an absolute colorspace but rather a 304 * mathematical transformation of RGB designed solely for storage and 305 * transmission. YCbCr images must be converted to RGB before they can 306 * actually be displayed. In the YCbCr colorspace, the Y (luminance) 307 * component represents the black & white portion of the original image, and 308 * the Cb and Cr (chrominance) components represent the color portion of the 309 * original image. Originally, the analog equivalent of this transformation 310 * allowed the same signal to drive both black & white and color televisions, 311 * but JPEG images use YCbCr primarily because it allows the color data to be 312 * optionally subsampled for the purposes of reducing bandwidth or disk 313 * space. YCbCr is the most common JPEG colorspace, and YCbCr JPEG images 314 * can be compressed from and decompressed to any of the extended RGB pixel 315 * formats or grayscale, or they can be decompressed to YUV planar images. 316 */ 317 TJCS_YCbCr, 318 /** 319 * Grayscale colorspace. The JPEG image retains only the luminance data (Y 320 * component), and any color data from the source image is discarded. 321 * Grayscale JPEG images can be compressed from and decompressed to any of 322 * the extended RGB pixel formats or grayscale, or they can be decompressed 323 * to YUV planar images. 324 */ 325 TJCS_GRAY, 326 /** 327 * CMYK colorspace. When compressing the JPEG image, the C, M, Y, and K 328 * components in the source image are reordered into image planes, but no 329 * colorspace conversion or subsampling is performed. CMYK JPEG images can 330 * only be decompressed to CMYK pixels. 331 */ 332 TJCS_CMYK, 333 /** 334 * YCCK colorspace. YCCK (AKA "YCbCrK") is not an absolute colorspace but 335 * rather a mathematical transformation of CMYK designed solely for storage 336 * and transmission. It is to CMYK as YCbCr is to RGB. CMYK pixels can be 337 * reversibly transformed into YCCK, and as with YCbCr, the chrominance 338 * components in the YCCK pixels can be subsampled without incurring major 339 * perceptual loss. YCCK JPEG images can only be compressed from and 340 * decompressed to CMYK pixels. 341 */ 342 TJCS_YCCK 343}; 344 345 346/** 347 * The uncompressed source/destination image is stored in bottom-up (Windows, 348 * OpenGL) order, not top-down (X11) order. 349 */ 350#define TJFLAG_BOTTOMUP 2 351/** 352 * When decompressing an image that was compressed using chrominance 353 * subsampling, use the fastest chrominance upsampling algorithm available in 354 * the underlying codec. The default is to use smooth upsampling, which 355 * creates a smooth transition between neighboring chrominance components in 356 * order to reduce upsampling artifacts in the decompressed image. 357 */ 358#define TJFLAG_FASTUPSAMPLE 256 359/** 360 * Disable buffer (re)allocation. If passed to one of the JPEG compression or 361 * transform functions, this flag will cause those functions to generate an 362 * error if the JPEG image buffer is invalid or too small rather than 363 * attempting to allocate or reallocate that buffer. This reproduces the 364 * behavior of earlier versions of TurboJPEG. 365 */ 366#define TJFLAG_NOREALLOC 1024 367/** 368 * Use the fastest DCT/IDCT algorithm available in the underlying codec. The 369 * default if this flag is not specified is implementation-specific. For 370 * example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast 371 * algorithm by default when compressing, because this has been shown to have 372 * only a very slight effect on accuracy, but it uses the accurate algorithm 373 * when decompressing, because this has been shown to have a larger effect. 374 */ 375#define TJFLAG_FASTDCT 2048 376/** 377 * Use the most accurate DCT/IDCT algorithm available in the underlying codec. 378 * The default if this flag is not specified is implementation-specific. For 379 * example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast 380 * algorithm by default when compressing, because this has been shown to have 381 * only a very slight effect on accuracy, but it uses the accurate algorithm 382 * when decompressing, because this has been shown to have a larger effect. 383 */ 384#define TJFLAG_ACCURATEDCT 4096 385 386 387/** 388 * The number of transform operations 389 */ 390#define TJ_NUMXOP 8 391 392/** 393 * Transform operations for #tjTransform() 394 */ 395enum TJXOP 396{ 397 /** 398 * Do not transform the position of the image pixels 399 */ 400 TJXOP_NONE=0, 401 /** 402 * Flip (mirror) image horizontally. This transform is imperfect if there 403 * are any partial MCU blocks on the right edge (see #TJXOPT_PERFECT.) 404 */ 405 TJXOP_HFLIP, 406 /** 407 * Flip (mirror) image vertically. This transform is imperfect if there are 408 * any partial MCU blocks on the bottom edge (see #TJXOPT_PERFECT.) 409 */ 410 TJXOP_VFLIP, 411 /** 412 * Transpose image (flip/mirror along upper left to lower right axis.) This 413 * transform is always perfect. 414 */ 415 TJXOP_TRANSPOSE, 416 /** 417 * Transverse transpose image (flip/mirror along upper right to lower left 418 * axis.) This transform is imperfect if there are any partial MCU blocks in 419 * the image (see #TJXOPT_PERFECT.) 420 */ 421 TJXOP_TRANSVERSE, 422 /** 423 * Rotate image clockwise by 90 degrees. This transform is imperfect if 424 * there are any partial MCU blocks on the bottom edge (see 425 * #TJXOPT_PERFECT.) 426 */ 427 TJXOP_ROT90, 428 /** 429 * Rotate image 180 degrees. This transform is imperfect if there are any 430 * partial MCU blocks in the image (see #TJXOPT_PERFECT.) 431 */ 432 TJXOP_ROT180, 433 /** 434 * Rotate image counter-clockwise by 90 degrees. This transform is imperfect 435 * if there are any partial MCU blocks on the right edge (see 436 * #TJXOPT_PERFECT.) 437 */ 438 TJXOP_ROT270 439}; 440 441 442/** 443 * This option will cause #tjTransform() to return an error if the transform is 444 * not perfect. Lossless transforms operate on MCU blocks, whose size depends 445 * on the level of chrominance subsampling used (see #tjMCUWidth 446 * and #tjMCUHeight.) If the image's width or height is not evenly divisible 447 * by the MCU block size, then there will be partial MCU blocks on the right 448 * and/or bottom edges. It is not possible to move these partial MCU blocks to 449 * the top or left of the image, so any transform that would require that is 450 * "imperfect." If this option is not specified, then any partial MCU blocks 451 * that cannot be transformed will be left in place, which will create 452 * odd-looking strips on the right or bottom edge of the image. 453 */ 454#define TJXOPT_PERFECT 1 455/** 456 * This option will cause #tjTransform() to discard any partial MCU blocks that 457 * cannot be transformed. 458 */ 459#define TJXOPT_TRIM 2 460/** 461 * This option will enable lossless cropping. See #tjTransform() for more 462 * information. 463 */ 464#define TJXOPT_CROP 4 465/** 466 * This option will discard the color data in the input image and produce 467 * a grayscale output image. 468 */ 469#define TJXOPT_GRAY 8 470/** 471 * This option will prevent #tjTransform() from outputting a JPEG image for 472 * this particular transform (this can be used in conjunction with a custom 473 * filter to capture the transformed DCT coefficients without transcoding 474 * them.) 475 */ 476#define TJXOPT_NOOUTPUT 16 477 478 479/** 480 * Scaling factor 481 */ 482typedef struct 483{ 484 /** 485 * Numerator 486 */ 487 int num; 488 /** 489 * Denominator 490 */ 491 int denom; 492} tjscalingfactor; 493 494/** 495 * Cropping region 496 */ 497typedef struct 498{ 499 /** 500 * The left boundary of the cropping region. This must be evenly divisible 501 * by the MCU block width (see #tjMCUWidth.) 502 */ 503 int x; 504 /** 505 * The upper boundary of the cropping region. This must be evenly divisible 506 * by the MCU block height (see #tjMCUHeight.) 507 */ 508 int y; 509 /** 510 * The width of the cropping region. Setting this to 0 is the equivalent of 511 * setting it to the width of the source JPEG image - x. 512 */ 513 int w; 514 /** 515 * The height of the cropping region. Setting this to 0 is the equivalent of 516 * setting it to the height of the source JPEG image - y. 517 */ 518 int h; 519} tjregion; 520 521/** 522 * Lossless transform 523 */ 524typedef struct tjtransform 525{ 526 /** 527 * Cropping region 528 */ 529 tjregion r; 530 /** 531 * One of the @ref TJXOP "transform operations" 532 */ 533 int op; 534 /** 535 * The bitwise OR of one of more of the @ref TJXOPT_CROP "transform options" 536 */ 537 int options; 538 /** 539 * Arbitrary data that can be accessed within the body of the callback 540 * function 541 */ 542 void *data; 543 /** 544 * A callback function that can be used to modify the DCT coefficients 545 * after they are losslessly transformed but before they are transcoded to a 546 * new JPEG image. This allows for custom filters or other transformations 547 * to be applied in the frequency domain. 548 * 549 * @param coeffs pointer to an array of transformed DCT coefficients. (NOTE: 550 * this pointer is not guaranteed to be valid once the callback returns, so 551 * applications wishing to hand off the DCT coefficients to another function 552 * or library should make a copy of them within the body of the callback.) 553 * 554 * @param arrayRegion #tjregion structure containing the width and height of 555 * the array pointed to by <tt>coeffs</tt> as well as its offset relative to 556 * the component plane. TurboJPEG implementations may choose to split each 557 * component plane into multiple DCT coefficient arrays and call the callback 558 * function once for each array. 559 * 560 * @param planeRegion #tjregion structure containing the width and height of 561 * the component plane to which <tt>coeffs</tt> belongs 562 * 563 * @param componentID ID number of the component plane to which 564 * <tt>coeffs</tt> belongs (Y, Cb, and Cr have, respectively, ID's of 0, 1, 565 * and 2 in typical JPEG images.) 566 * 567 * @param transformID ID number of the transformed image to which 568 * <tt>coeffs</tt> belongs. This is the same as the index of the transform 569 * in the <tt>transforms</tt> array that was passed to #tjTransform(). 570 * 571 * @param transform a pointer to a #tjtransform structure that specifies the 572 * parameters and/or cropping region for this transform 573 * 574 * @return 0 if the callback was successful, or -1 if an error occurred. 575 */ 576 int (*customFilter)(short *coeffs, tjregion arrayRegion, 577 tjregion planeRegion, int componentIndex, int transformIndex, 578 struct tjtransform *transform); 579} tjtransform; 580 581/** 582 * TurboJPEG instance handle 583 */ 584typedef void* tjhandle; 585 586 587/** 588 * Pad the given width to the nearest 32-bit boundary 589 */ 590#define TJPAD(width) (((width)+3)&(~3)) 591 592/** 593 * Compute the scaled value of <tt>dimension</tt> using the given scaling 594 * factor. This macro performs the integer equivalent of <tt>ceil(dimension * 595 * scalingFactor)</tt>. 596 */ 597#define TJSCALED(dimension, scalingFactor) ((dimension * scalingFactor.num \ 598 + scalingFactor.denom - 1) / scalingFactor.denom) 599 600 601#ifdef __cplusplus 602extern "C" { 603#endif 604 605 606/** 607 * Create a TurboJPEG compressor instance. 608 * 609 * @return a handle to the newly-created instance, or NULL if an error 610 * occurred (see #tjGetErrorStr().) 611 */ 612DLLEXPORT tjhandle DLLCALL tjInitCompress(void); 613 614 615/** 616 * Compress an RGB, grayscale, or CMYK image into a JPEG image. 617 * 618 * @param handle a handle to a TurboJPEG compressor or transformer instance 619 * 620 * @param srcBuf pointer to an image buffer containing RGB, grayscale, or 621 * CMYK pixels to be compressed 622 * 623 * @param width width (in pixels) of the source image 624 * 625 * @param pitch bytes per line in the source image. Normally, this should be 626 * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or 627 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image 628 * is padded to the nearest 32-bit boundary, as is the case for Windows 629 * bitmaps. You can also be clever and use this parameter to skip lines, etc. 630 * Setting this parameter to 0 is the equivalent of setting it to 631 * <tt>width * #tjPixelSize[pixelFormat]</tt>. 632 * 633 * @param height height (in pixels) of the source image 634 * 635 * @param pixelFormat pixel format of the source image (see @ref TJPF 636 * "Pixel formats".) 637 * 638 * @param jpegBuf address of a pointer to an image buffer that will receive the 639 * JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer 640 * to accommodate the size of the JPEG image. Thus, you can choose to: 641 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and 642 * let TurboJPEG grow the buffer as needed, 643 * -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer 644 * for you, or 645 * -# pre-allocate the buffer to a "worst case" size determined by calling 646 * #tjBufSize(). This should ensure that the buffer never has to be 647 * re-allocated (setting #TJFLAG_NOREALLOC guarantees that it won't be.) 648 * . 649 * If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your 650 * pre-allocated buffer. In any case, unless you have set #TJFLAG_NOREALLOC, 651 * you should always check <tt>*jpegBuf</tt> upon return from this function, as 652 * it may have changed. 653 * 654 * @param jpegSize pointer to an unsigned long variable that holds the size of 655 * the JPEG image buffer. If <tt>*jpegBuf</tt> points to a pre-allocated 656 * buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer. 657 * Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in 658 * bytes.) If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being 659 * reused from a previous call to one of the JPEG compression functions, then 660 * <tt>*jpegSize</tt> is ignored. 661 * 662 * @param jpegSubsamp the level of chrominance subsampling to be used when 663 * generating the JPEG image (see @ref TJSAMP 664 * "Chrominance subsampling options".) 665 * 666 * @param jpegQual the image quality of the generated JPEG image (1 = worst, 667 * 100 = best) 668 * 669 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 670 * "flags" 671 * 672 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 673*/ 674DLLEXPORT int DLLCALL tjCompress2(tjhandle handle, const unsigned char *srcBuf, 675 int width, int pitch, int height, int pixelFormat, unsigned char **jpegBuf, 676 unsigned long *jpegSize, int jpegSubsamp, int jpegQual, int flags); 677 678 679/** 680 * Compress a YUV planar image into a JPEG image. 681 * 682 * @param handle a handle to a TurboJPEG compressor or transformer instance 683 * 684 * @param srcBuf pointer to an image buffer containing a YUV planar image to be 685 * compressed. The size of this buffer should match the value returned by 686 * #tjBufSizeYUV2() for the given image width, height, padding, and level of 687 * chrominance subsampling. The Y, U (Cb), and V (Cr) image planes should be 688 * stored sequentially in the source buffer (refer to @ref YUVnotes 689 * "YUV Image Format Notes".) 690 * 691 * @param width width (in pixels) of the source image. If the width is not an 692 * even multiple of the MCU block width (see #tjMCUWidth), then an intermediate 693 * buffer copy will be performed within TurboJPEG. 694 * 695 * @param pad the line padding used in the source image. For instance, if each 696 * line in each plane of the YUV image is padded to the nearest multiple of 4 697 * bytes, then <tt>pad</tt> should be set to 4. 698 * 699 * @param height height (in pixels) of the source image. If the height is not 700 * an even multiple of the MCU block height (see #tjMCUHeight), then an 701 * intermediate buffer copy will be performed within TurboJPEG. 702 * 703 * @param subsamp the level of chrominance subsampling used in the source 704 * image (see @ref TJSAMP "Chrominance subsampling options".) 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 to 708 * 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 jpegQual the image quality of the generated JPEG image (1 = worst, 731 * 100 = best) 732 * 733 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 734 * "flags" 735 * 736 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 737*/ 738DLLEXPORT int DLLCALL tjCompressFromYUV(tjhandle handle, 739 const unsigned char *srcBuf, int width, int pad, int height, int subsamp, 740 unsigned char **jpegBuf, unsigned long *jpegSize, int jpegQual, int flags); 741 742 743/** 744 * Compress a set of Y, U (Cb), and V (Cr) image planes into a JPEG image. 745 * 746 * @param handle a handle to a TurboJPEG compressor or transformer instance 747 * 748 * @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes 749 * (or just a Y plane, if compressing a grayscale image) that contain a YUV 750 * image to be compressed. These planes can be contiguous or non-contiguous in 751 * memory. The size of each plane should match the value returned by 752 * #tjPlaneSizeYUV() for the given image width, height, strides, and level of 753 * chrominance subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" 754 * for more details. 755 * 756 * @param width width (in pixels) of the source image. If the width is not an 757 * even multiple of the MCU block width (see #tjMCUWidth), then an intermediate 758 * buffer copy will be performed within TurboJPEG. 759 * 760 * @param strides an array of integers, each specifying the number of bytes per 761 * line in the corresponding plane of the YUV source image. Setting the stride 762 * for any plane to 0 is the same as setting it to the plane width (see 763 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then 764 * the strides for all planes will be set to their respective plane widths. 765 * You can adjust the strides in order to specify an arbitrary amount of line 766 * padding in each plane or to create a JPEG image from a subregion of a larger 767 * YUV planar image. 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 #tjGetErrorStr().) 807*/ 808DLLEXPORT int DLLCALL tjCompressFromYUVPlanes(tjhandle handle, 809 const unsigned char **srcPlanes, int width, const int *strides, int height, 810 int subsamp, unsigned char **jpegBuf, unsigned long *jpegSize, int jpegQual, 811 int flags); 812 813 814/** 815 * The maximum size of the buffer (in bytes) required to hold a JPEG image with 816 * the given parameters. The number of bytes returned by this function is 817 * larger than the size of the uncompressed source image. The reason for this 818 * is that the JPEG format uses 16-bit coefficients, and it is thus possible 819 * for a very high-quality JPEG image with very high-frequency content to 820 * expand rather than compress when converted to the JPEG format. Such images 821 * represent a very rare corner case, but since there is no way to predict the 822 * size of a JPEG image prior to compression, the corner case has to be 823 * handled. 824 * 825 * @param width width (in pixels) of the image 826 * 827 * @param height height (in pixels) of the image 828 * 829 * @param jpegSubsamp the level of chrominance subsampling to be used when 830 * generating the JPEG image (see @ref TJSAMP 831 * "Chrominance subsampling options".) 832 * 833 * @return the maximum size of the buffer (in bytes) required to hold the 834 * image, or -1 if the arguments are out of bounds. 835 */ 836DLLEXPORT unsigned long DLLCALL tjBufSize(int width, int height, 837 int jpegSubsamp); 838 839 840/** 841 * The size of the buffer (in bytes) required to hold a YUV planar image with 842 * the given parameters. 843 * 844 * @param width width (in pixels) of the image 845 * 846 * @param pad the width of each line in each plane of the image is padded to 847 * the nearest multiple of this number of bytes (must be a power of 2.) 848 * 849 * @param height height (in pixels) of the image 850 * 851 * @param subsamp level of chrominance subsampling in the image (see 852 * @ref TJSAMP "Chrominance subsampling options".) 853 * 854 * @return the size of the buffer (in bytes) required to hold the image, or 855 * -1 if the arguments are out of bounds. 856 */ 857DLLEXPORT unsigned long DLLCALL tjBufSizeYUV2(int width, int pad, int height, 858 int subsamp); 859 860 861/** 862 * The size of the buffer (in bytes) required to hold a YUV image plane with 863 * the given parameters. 864 * 865 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr) 866 * 867 * @param width width (in pixels) of the YUV image. NOTE: this is the width of 868 * the whole image, not the plane width. 869 * 870 * @param stride bytes per line in the image plane. Setting this to 0 is the 871 * equivalent of setting it to the plane width. 872 * 873 * @param height height (in pixels) of the YUV image. NOTE: this is the height 874 * of the whole image, not the plane height. 875 * 876 * @param subsamp level of chrominance subsampling in the image (see 877 * @ref TJSAMP "Chrominance subsampling options".) 878 * 879 * @return the size of the buffer (in bytes) required to hold the YUV image 880 * plane, or -1 if the arguments are out of bounds. 881 */ 882DLLEXPORT unsigned long DLLCALL tjPlaneSizeYUV(int componentID, int width, 883 int stride, int height, int subsamp); 884 885 886/** 887 * The plane width of a YUV image plane with the given parameters. Refer to 888 * @ref YUVnotes "YUV Image Format Notes" for a description of plane width. 889 * 890 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr) 891 * 892 * @param width width (in pixels) of the YUV image 893 * 894 * @param subsamp level of chrominance subsampling in the image (see 895 * @ref TJSAMP "Chrominance subsampling options".) 896 * 897 * @return the plane width of a YUV image plane with the given parameters, or 898 * -1 if the arguments are out of bounds. 899 */ 900DLLEXPORT int tjPlaneWidth(int componentID, int width, int subsamp); 901 902 903/** 904 * The plane height of a YUV image plane with the given parameters. Refer to 905 * @ref YUVnotes "YUV Image Format Notes" for a description of plane height. 906 * 907 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr) 908 * 909 * @param height height (in pixels) of the YUV image 910 * 911 * @param subsamp level of chrominance subsampling in the image (see 912 * @ref TJSAMP "Chrominance subsampling options".) 913 * 914 * @return the plane height of a YUV image plane with the given parameters, or 915 * -1 if the arguments are out of bounds. 916 */ 917DLLEXPORT int tjPlaneHeight(int componentID, int height, int subsamp); 918 919 920/** 921 * Encode an RGB or grayscale image into a YUV planar image. This function 922 * uses the accelerated color conversion routines in the underlying 923 * codec but does not execute any of the other steps in the JPEG compression 924 * process. 925 * 926 * @param handle a handle to a TurboJPEG compressor or transformer instance 927 * 928 * @param srcBuf pointer to an image buffer containing RGB or grayscale pixels 929 * to be encoded 930 * 931 * @param width width (in pixels) of the source image 932 * 933 * @param pitch bytes per line in the source image. Normally, this should be 934 * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or 935 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image 936 * is padded to the nearest 32-bit boundary, as is the case for Windows 937 * bitmaps. You can also be clever and use this parameter to skip lines, etc. 938 * Setting this parameter to 0 is the equivalent of setting it to 939 * <tt>width * #tjPixelSize[pixelFormat]</tt>. 940 * 941 * @param height height (in pixels) of the source image 942 * 943 * @param pixelFormat pixel format of the source image (see @ref TJPF 944 * "Pixel formats".) 945 * 946 * @param dstBuf pointer to an image buffer that will receive the YUV image. 947 * Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based 948 * on the image width, height, padding, and level of chrominance subsampling. 949 * The Y, U (Cb), and V (Cr) image planes will be stored sequentially in the 950 * buffer (refer to @ref YUVnotes "YUV Image Format Notes".) 951 * 952 * @param pad the width of each line in each plane of the YUV image will be 953 * padded to the nearest multiple of this number of bytes (must be a power of 954 * 2.) To generate images suitable for X Video, <tt>pad</tt> should be set to 955 * 4. 956 * 957 * @param subsamp the level of chrominance subsampling to be used when 958 * generating the YUV image (see @ref TJSAMP 959 * "Chrominance subsampling options".) To generate images suitable for X 960 * Video, <tt>subsamp</tt> should be set to @ref TJSAMP_420. This produces an 961 * image compatible with the I420 (AKA "YUV420P") format. 962 * 963 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 964 * "flags" 965 * 966 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 967*/ 968DLLEXPORT int DLLCALL tjEncodeYUV3(tjhandle handle, 969 const unsigned char *srcBuf, int width, int pitch, int height, 970 int pixelFormat, unsigned char *dstBuf, int pad, int subsamp, int flags); 971 972 973/** 974 * Encode an RGB or grayscale image into separate Y, U (Cb), and V (Cr) image 975 * planes. This function uses the accelerated color conversion routines in the 976 * underlying codec but does not execute any of the other steps in the JPEG 977 * compression process. 978 * 979 * @param handle a handle to a TurboJPEG compressor or transformer instance 980 * 981 * @param srcBuf pointer to an image buffer containing RGB or grayscale pixels 982 * to be encoded 983 * 984 * @param width width (in pixels) of the source image 985 * 986 * @param pitch bytes per line in the source image. Normally, this should be 987 * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or 988 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image 989 * is padded to the nearest 32-bit boundary, as is the case for Windows 990 * bitmaps. You can also be clever and use this parameter to skip lines, etc. 991 * Setting this parameter to 0 is the equivalent of setting it to 992 * <tt>width * #tjPixelSize[pixelFormat]</tt>. 993 * 994 * @param height height (in pixels) of the source image 995 * 996 * @param pixelFormat pixel format of the source image (see @ref TJPF 997 * "Pixel formats".) 998 * 999 * @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes 1000 * (or just a Y plane, if generating a grayscale image) that will receive the 1001 * encoded image. These planes can be contiguous or non-contiguous in memory. 1002 * Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based 1003 * on the image width, height, strides, and level of chrominance subsampling. 1004 * Refer to @ref YUVnotes "YUV Image Format Notes" for more details. 1005 * 1006 * @param strides an array of integers, each specifying the number of bytes per 1007 * line in the corresponding plane of the output image. Setting the stride for 1008 * any plane to 0 is the same as setting it to the plane width (see 1009 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then 1010 * the strides for all planes will be set to their respective plane widths. 1011 * You can adjust the strides in order to add an arbitrary amount of line 1012 * padding to each plane or to encode an RGB or grayscale image into a 1013 * subregion of a larger YUV planar image. 1014 * 1015 * @param subsamp the level of chrominance subsampling to be used when 1016 * generating the YUV image (see @ref TJSAMP 1017 * "Chrominance subsampling options".) To generate images suitable for X 1018 * Video, <tt>subsamp</tt> should be set to @ref TJSAMP_420. This produces an 1019 * image compatible with the I420 (AKA "YUV420P") format. 1020 * 1021 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1022 * "flags" 1023 * 1024 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1025*/ 1026DLLEXPORT int DLLCALL tjEncodeYUVPlanes(tjhandle handle, 1027 const unsigned char *srcBuf, int width, int pitch, int height, 1028 int pixelFormat, unsigned char **dstPlanes, int *strides, int subsamp, 1029 int flags); 1030 1031 1032/** 1033 * Create a TurboJPEG decompressor instance. 1034 * 1035 * @return a handle to the newly-created instance, or NULL if an error 1036 * occurred (see #tjGetErrorStr().) 1037*/ 1038DLLEXPORT tjhandle DLLCALL tjInitDecompress(void); 1039 1040 1041/** 1042 * Retrieve information about a JPEG image without decompressing it. 1043 * 1044 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1045 * 1046 * @param jpegBuf pointer to a buffer containing a JPEG image 1047 * 1048 * @param jpegSize size of the JPEG image (in bytes) 1049 * 1050 * @param width pointer to an integer variable that will receive the width (in 1051 * pixels) of the JPEG image 1052 * 1053 * @param height pointer to an integer variable that will receive the height 1054 * (in pixels) of the JPEG image 1055 * 1056 * @param jpegSubsamp pointer to an integer variable that will receive the 1057 * level of chrominance subsampling used when the JPEG image was compressed 1058 * (see @ref TJSAMP "Chrominance subsampling options".) 1059 * 1060 * @param jpegColorspace pointer to an integer variable that will receive one 1061 * of the JPEG colorspace constants, indicating the colorspace of the JPEG 1062 * image (see @ref TJCS "JPEG colorspaces".) 1063 * 1064 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1065*/ 1066DLLEXPORT int DLLCALL tjDecompressHeader3(tjhandle handle, 1067 const unsigned char *jpegBuf, unsigned long jpegSize, int *width, 1068 int *height, int *jpegSubsamp, int *jpegColorspace); 1069 1070 1071/** 1072 * Returns a list of fractional scaling factors that the JPEG decompressor in 1073 * this implementation of TurboJPEG supports. 1074 * 1075 * @param numscalingfactors pointer to an integer variable that will receive 1076 * the number of elements in the list 1077 * 1078 * @return a pointer to a list of fractional scaling factors, or NULL if an 1079 * error is encountered (see #tjGetErrorStr().) 1080*/ 1081DLLEXPORT tjscalingfactor* DLLCALL tjGetScalingFactors(int *numscalingfactors); 1082 1083 1084/** 1085 * Decompress a JPEG image to an RGB, grayscale, or CMYK image. 1086 * 1087 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1088 * 1089 * @param jpegBuf pointer to a buffer containing the JPEG image to decompress 1090 * 1091 * @param jpegSize size of the JPEG image (in bytes) 1092 * 1093 * @param dstBuf pointer to an image buffer that will receive the decompressed 1094 * image. This buffer should normally be <tt>pitch * scaledHeight</tt> bytes 1095 * in size, where <tt>scaledHeight</tt> can be determined by calling 1096 * #TJSCALED() with the JPEG image height and one of the scaling factors 1097 * returned by #tjGetScalingFactors(). The <tt>dstBuf</tt> pointer may also be 1098 * used to decompress into a specific region of a larger buffer. 1099 * 1100 * @param width desired width (in pixels) of the destination image. If this is 1101 * different than the width of the JPEG image being decompressed, then 1102 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1103 * possible image that will fit within the desired width. If <tt>width</tt> is 1104 * set to 0, then only the height will be considered when determining the 1105 * scaled image size. 1106 * 1107 * @param pitch bytes per line in the destination image. Normally, this is 1108 * <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt> if the decompressed image 1109 * is unpadded, else <tt>#TJPAD(scaledWidth * #tjPixelSize[pixelFormat])</tt> 1110 * if each line of the decompressed image is padded to the nearest 32-bit 1111 * boundary, as is the case for Windows bitmaps. (NOTE: <tt>scaledWidth</tt> 1112 * can be determined by calling #TJSCALED() with the JPEG image width and one 1113 * of the scaling factors returned by #tjGetScalingFactors().) You can also be 1114 * clever and use the pitch parameter to skip lines, etc. Setting this 1115 * parameter to 0 is the equivalent of setting it to 1116 * <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt>. 1117 * 1118 * @param height desired height (in pixels) of the destination image. If this 1119 * is different than the height of the JPEG image being decompressed, then 1120 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1121 * possible image that will fit within the desired height. If <tt>height</tt> 1122 * is set to 0, then only the width will be considered when determining the 1123 * scaled image size. 1124 * 1125 * @param pixelFormat pixel format of the destination image (see @ref 1126 * TJPF "Pixel formats".) 1127 * 1128 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1129 * "flags" 1130 * 1131 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1132 */ 1133DLLEXPORT int DLLCALL tjDecompress2(tjhandle handle, 1134 const unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf, 1135 int width, int pitch, int height, int pixelFormat, int flags); 1136 1137 1138/** 1139 * Decompress a JPEG image to a YUV planar image. This function performs JPEG 1140 * decompression but leaves out the color conversion step, so a planar YUV 1141 * image is generated instead of an RGB image. 1142 * 1143 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1144 * 1145 * @param jpegBuf pointer to a buffer containing the JPEG image to decompress 1146 * 1147 * @param jpegSize size of the JPEG image (in bytes) 1148 * 1149 * @param dstBuf pointer to an image buffer that will receive the YUV image. 1150 * Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based 1151 * on the image width, height, padding, and level of subsampling. The Y, 1152 * U (Cb), and V (Cr) image planes will be stored sequentially in the buffer 1153 * (refer to @ref YUVnotes "YUV Image Format Notes".) 1154 * 1155 * @param width desired width (in pixels) of the YUV image. If this is 1156 * different than the width of the JPEG image being decompressed, then 1157 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1158 * possible image that will fit within the desired width. If <tt>width</tt> is 1159 * set to 0, then only the height will be considered when determining the 1160 * scaled image size. If the scaled width is not an even multiple of the MCU 1161 * block width (see #tjMCUWidth), then an intermediate buffer copy will be 1162 * performed within TurboJPEG. 1163 * 1164 * @param pad the width of each line in each plane of the YUV image will be 1165 * padded to the nearest multiple of this number of bytes (must be a power of 1166 * 2.) To generate images suitable for X Video, <tt>pad</tt> should be set to 1167 * 4. 1168 * 1169 * @param height desired height (in pixels) of the YUV image. If this is 1170 * different than the height of the JPEG image being decompressed, then 1171 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1172 * possible image that will fit within the desired height. If <tt>height</tt> 1173 * is set to 0, then only the width will be considered when determining the 1174 * scaled image size. If the scaled height is not an even multiple of the MCU 1175 * block height (see #tjMCUHeight), then an intermediate buffer copy will be 1176 * performed within TurboJPEG. 1177 * 1178 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1179 * "flags" 1180 * 1181 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1182 */ 1183DLLEXPORT int DLLCALL tjDecompressToYUV2(tjhandle handle, 1184 const unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf, 1185 int width, int pad, int height, int flags); 1186 1187 1188/** 1189 * Decompress a JPEG image into separate Y, U (Cb), and V (Cr) image 1190 * planes. This function performs JPEG decompression but leaves out the color 1191 * conversion step, so a planar YUV image is generated instead of an RGB image. 1192 * 1193 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1194 * 1195 * @param jpegBuf pointer to a buffer containing the JPEG image to decompress 1196 * 1197 * @param jpegSize size of the JPEG image (in bytes) 1198 * 1199 * @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes 1200 * (or just a Y plane, if decompressing a grayscale image) that will receive 1201 * the YUV image. These planes can be contiguous or non-contiguous in memory. 1202 * Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based 1203 * on the scaled image width, scaled image height, strides, and level of 1204 * chrominance subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" 1205 * for more details. 1206 * 1207 * @param width desired width (in pixels) of the YUV image. If this is 1208 * different than the width of the JPEG image being decompressed, then 1209 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1210 * possible image that will fit within the desired width. If <tt>width</tt> is 1211 * set to 0, then only the height will be considered when determining the 1212 * scaled image size. If the scaled width is not an even multiple of the MCU 1213 * block width (see #tjMCUWidth), then an intermediate buffer copy will be 1214 * performed within TurboJPEG. 1215 * 1216 * @param strides an array of integers, each specifying the number of bytes per 1217 * line in the corresponding plane of the output image. Setting the stride for 1218 * any plane to 0 is the same as setting it to the scaled plane width (see 1219 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then 1220 * the strides for all planes will be set to their respective scaled plane 1221 * widths. You can adjust the strides in order to add an arbitrary amount of 1222 * line padding to each plane or to decompress the JPEG image into a subregion 1223 * of a larger YUV planar image. 1224 * 1225 * @param height desired height (in pixels) of the YUV image. If this is 1226 * different than the height of the JPEG image being decompressed, then 1227 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1228 * possible image that will fit within the desired height. If <tt>height</tt> 1229 * is set to 0, then only the width will be considered when determining the 1230 * scaled image size. If the scaled height is not an even multiple of the MCU 1231 * block height (see #tjMCUHeight), then an intermediate buffer copy will be 1232 * performed within TurboJPEG. 1233 * 1234 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1235 * "flags" 1236 * 1237 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1238 */ 1239DLLEXPORT int DLLCALL tjDecompressToYUVPlanes(tjhandle handle, 1240 const unsigned char *jpegBuf, unsigned long jpegSize, 1241 unsigned char **dstPlanes, int width, int *strides, int height, int flags); 1242 1243 1244/** 1245 * Decode a YUV planar image into an RGB or grayscale image. This function 1246 * uses the accelerated color conversion routines in the underlying 1247 * codec but does not execute any of the other steps in the JPEG decompression 1248 * process. 1249 * 1250 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1251 * 1252 * @param srcBuf pointer to an image buffer containing a YUV planar image to be 1253 * decoded. The size of this buffer should match the value returned by 1254 * #tjBufSizeYUV2() for the given image width, height, padding, and level of 1255 * chrominance subsampling. The Y, U (Cb), and V (Cr) image planes should be 1256 * stored sequentially in the source buffer (refer to @ref YUVnotes 1257 * "YUV Image Format Notes".) 1258 * 1259 * @param pad Use this parameter to specify that the width of each line in each 1260 * plane of the YUV source image is padded to the nearest multiple of this 1261 * number of bytes (must be a power of 2.) 1262 * 1263 * @param subsamp the level of chrominance subsampling used in the YUV source 1264 * image (see @ref TJSAMP "Chrominance subsampling options".) 1265 * 1266 * @param dstBuf pointer to an image buffer that will receive the decoded 1267 * image. This buffer should normally be <tt>pitch * height</tt> bytes in 1268 * size, but the <tt>dstBuf</tt> pointer can also be used to decode into a 1269 * specific region of a larger buffer. 1270 * 1271 * @param width width (in pixels) of the source and destination images 1272 * 1273 * @param pitch bytes per line in the destination image. Normally, this should 1274 * be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is 1275 * unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line 1276 * of the destination image should be padded to the nearest 32-bit boundary, as 1277 * is the case for Windows bitmaps. You can also be clever and use the pitch 1278 * parameter to skip lines, etc. Setting this parameter to 0 is the equivalent 1279 * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>. 1280 * 1281 * @param height height (in pixels) of the source and destination images 1282 * 1283 * @param pixelFormat pixel format of the destination image (see @ref TJPF 1284 * "Pixel formats".) 1285 * 1286 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1287 * "flags" 1288 * 1289 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1290 */ 1291DLLEXPORT int DLLCALL tjDecodeYUV(tjhandle handle, const unsigned char *srcBuf, 1292 int pad, int subsamp, unsigned char *dstBuf, int width, int pitch, 1293 int height, int pixelFormat, int flags); 1294 1295 1296/** 1297 * Decode a set of Y, U (Cb), and V (Cr) image planes into an RGB or grayscale 1298 * image. This function uses the accelerated color conversion routines in the 1299 * underlying codec but does not execute any of the other steps in the JPEG 1300 * decompression process. 1301 * 1302 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1303 * 1304 * @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes 1305 * (or just a Y plane, if decoding a grayscale image) that contain a YUV image 1306 * to be decoded. These planes can be contiguous or non-contiguous in memory. 1307 * The size of each plane should match the value returned by #tjPlaneSizeYUV() 1308 * for the given image width, height, strides, and level of chrominance 1309 * subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" for more 1310 * details. 1311 * 1312 * @param strides an array of integers, each specifying the number of bytes per 1313 * line in the corresponding plane of the YUV source image. Setting the stride 1314 * for any plane to 0 is the same as setting it to the 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 plane widths. 1317 * You can adjust the strides in order to specify an arbitrary amount of line 1318 * padding in each plane or to decode a subregion of a larger YUV planar image. 1319 * 1320 * @param subsamp the level of chrominance subsampling used in the YUV source 1321 * image (see @ref TJSAMP "Chrominance subsampling options".) 1322 * 1323 * @param dstBuf pointer to an image buffer that will receive the decoded 1324 * image. This buffer should normally be <tt>pitch * height</tt> bytes in 1325 * size, but the <tt>dstBuf</tt> pointer can also be used to decode into a 1326 * specific region of a larger buffer. 1327 * 1328 * @param width width (in pixels) of the source and destination images 1329 * 1330 * @param pitch bytes per line in the destination image. Normally, this should 1331 * be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is 1332 * unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line 1333 * of the destination image should be padded to the nearest 32-bit boundary, as 1334 * is the case for Windows bitmaps. You can also be clever and use the pitch 1335 * parameter to skip lines, etc. Setting this parameter to 0 is the equivalent 1336 * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>. 1337 * 1338 * @param height height (in pixels) of the source and destination images 1339 * 1340 * @param pixelFormat pixel format of the destination image (see @ref TJPF 1341 * "Pixel formats".) 1342 * 1343 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1344 * "flags" 1345 * 1346 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1347 */ 1348DLLEXPORT int DLLCALL tjDecodeYUVPlanes(tjhandle handle, 1349 const unsigned char **srcPlanes, const int *strides, int subsamp, 1350 unsigned char *dstBuf, int width, int pitch, int height, int pixelFormat, 1351 int flags); 1352 1353 1354/** 1355 * Create a new TurboJPEG transformer instance. 1356 * 1357 * @return a handle to the newly-created instance, or NULL if an error 1358 * occurred (see #tjGetErrorStr().) 1359 */ 1360DLLEXPORT tjhandle DLLCALL tjInitTransform(void); 1361 1362 1363/** 1364 * Losslessly transform a JPEG image into another JPEG image. Lossless 1365 * transforms work by moving the raw DCT coefficients from one JPEG image 1366 * structure to another without altering the values of the coefficients. While 1367 * this is typically faster than decompressing the image, transforming it, and 1368 * re-compressing it, lossless transforms are not free. Each lossless 1369 * transform requires reading and performing Huffman decoding on all of the 1370 * coefficients in the source image, regardless of the size of the destination 1371 * image. Thus, this function provides a means of generating multiple 1372 * transformed images from the same source or applying multiple 1373 * transformations simultaneously, in order to eliminate the need to read the 1374 * source coefficients multiple times. 1375 * 1376 * @param handle a handle to a TurboJPEG transformer instance 1377 * 1378 * @param jpegBuf pointer to a buffer containing the JPEG source image to 1379 * transform 1380 * 1381 * @param jpegSize size of the JPEG source image (in bytes) 1382 * 1383 * @param n the number of transformed JPEG images to generate 1384 * 1385 * @param dstBufs pointer to an array of n image buffers. <tt>dstBufs[i]</tt> 1386 * will receive a JPEG image that has been transformed using the parameters in 1387 * <tt>transforms[i]</tt>. TurboJPEG has the ability to reallocate the JPEG 1388 * buffer to accommodate the size of the JPEG image. Thus, you can choose to: 1389 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and 1390 * let TurboJPEG grow the buffer as needed, 1391 * -# set <tt>dstBufs[i]</tt> to NULL to tell TurboJPEG to allocate the buffer 1392 * for you, or 1393 * -# pre-allocate the buffer to a "worst case" size determined by calling 1394 * #tjBufSize() with the transformed or cropped width and height. Under normal 1395 * circumstances, this should ensure that the buffer never has to be 1396 * re-allocated (setting #TJFLAG_NOREALLOC guarantees that it won't be.) Note, 1397 * however, that there are some rare cases (such as transforming images with a 1398 * large amount of embedded EXIF or ICC profile data) in which the output image 1399 * will be larger than the worst-case size, and #TJFLAG_NOREALLOC cannot be 1400 * used in those cases. 1401 * . 1402 * If you choose option 1, <tt>dstSizes[i]</tt> should be set to the size of 1403 * your pre-allocated buffer. In any case, unless you have set 1404 * #TJFLAG_NOREALLOC, you should always check <tt>dstBufs[i]</tt> upon return 1405 * from this function, as it may have changed. 1406 * 1407 * @param dstSizes pointer to an array of n unsigned long variables that will 1408 * receive the actual sizes (in bytes) of each transformed JPEG image. If 1409 * <tt>dstBufs[i]</tt> points to a pre-allocated buffer, then 1410 * <tt>dstSizes[i]</tt> should be set to the size of the buffer. Upon return, 1411 * <tt>dstSizes[i]</tt> will contain the size of the JPEG image (in bytes.) 1412 * 1413 * @param transforms pointer to an array of n #tjtransform structures, each of 1414 * which specifies the transform parameters and/or cropping region for the 1415 * corresponding transformed output image. 1416 * 1417 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT 1418 * "flags" 1419 * 1420 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1421 */ 1422DLLEXPORT int DLLCALL tjTransform(tjhandle handle, 1423 const unsigned char *jpegBuf, unsigned long jpegSize, int n, 1424 unsigned char **dstBufs, unsigned long *dstSizes, tjtransform *transforms, 1425 int flags); 1426 1427 1428/** 1429 * Destroy a TurboJPEG compressor, decompressor, or transformer instance. 1430 * 1431 * @param handle a handle to a TurboJPEG compressor, decompressor or 1432 * transformer instance 1433 * 1434 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1435 */ 1436DLLEXPORT int DLLCALL tjDestroy(tjhandle handle); 1437 1438 1439/** 1440 * Allocate an image buffer for use with TurboJPEG. You should always use 1441 * this function to allocate the JPEG destination buffer(s) for the compression 1442 * and transform functions unless you are disabling automatic buffer 1443 * (re)allocation (by setting #TJFLAG_NOREALLOC.) 1444 * 1445 * @param bytes the number of bytes to allocate 1446 * 1447 * @return a pointer to a newly-allocated buffer with the specified number of 1448 * bytes. 1449 * 1450 * @sa tjFree() 1451 */ 1452DLLEXPORT unsigned char* DLLCALL tjAlloc(int bytes); 1453 1454 1455/** 1456 * Free an image buffer previously allocated by TurboJPEG. You should always 1457 * use this function to free JPEG destination buffer(s) that were automatically 1458 * (re)allocated by the compression and transform functions or that were 1459 * manually allocated using #tjAlloc(). 1460 * 1461 * @param buffer address of the buffer to free 1462 * 1463 * @sa tjAlloc() 1464 */ 1465DLLEXPORT void DLLCALL tjFree(unsigned char *buffer); 1466 1467 1468/** 1469 * Returns a descriptive error message explaining why the last command failed. 1470 * 1471 * @return a descriptive error message explaining why the last command failed. 1472 */ 1473DLLEXPORT char* DLLCALL tjGetErrorStr(void); 1474 1475 1476/* Deprecated functions and macros */ 1477#define TJFLAG_FORCEMMX 8 1478#define TJFLAG_FORCESSE 16 1479#define TJFLAG_FORCESSE2 32 1480#define TJFLAG_FORCESSE3 128 1481 1482 1483/* Backward compatibility functions and macros (nothing to see here) */ 1484#define NUMSUBOPT TJ_NUMSAMP 1485#define TJ_444 TJSAMP_444 1486#define TJ_422 TJSAMP_422 1487#define TJ_420 TJSAMP_420 1488#define TJ_411 TJSAMP_420 1489#define TJ_GRAYSCALE TJSAMP_GRAY 1490 1491#define TJ_BGR 1 1492#define TJ_BOTTOMUP TJFLAG_BOTTOMUP 1493#define TJ_FORCEMMX TJFLAG_FORCEMMX 1494#define TJ_FORCESSE TJFLAG_FORCESSE 1495#define TJ_FORCESSE2 TJFLAG_FORCESSE2 1496#define TJ_ALPHAFIRST 64 1497#define TJ_FORCESSE3 TJFLAG_FORCESSE3 1498#define TJ_FASTUPSAMPLE TJFLAG_FASTUPSAMPLE 1499#define TJ_YUV 512 1500 1501DLLEXPORT unsigned long DLLCALL TJBUFSIZE(int width, int height); 1502 1503DLLEXPORT unsigned long DLLCALL TJBUFSIZEYUV(int width, int height, 1504 int jpegSubsamp); 1505 1506DLLEXPORT unsigned long DLLCALL tjBufSizeYUV(int width, int height, 1507 int subsamp); 1508 1509DLLEXPORT int DLLCALL tjCompress(tjhandle handle, unsigned char *srcBuf, 1510 int width, int pitch, int height, int pixelSize, unsigned char *dstBuf, 1511 unsigned long *compressedSize, int jpegSubsamp, int jpegQual, int flags); 1512 1513DLLEXPORT int DLLCALL tjEncodeYUV(tjhandle handle, 1514 unsigned char *srcBuf, int width, int pitch, int height, int pixelSize, 1515 unsigned char *dstBuf, int subsamp, int flags); 1516 1517DLLEXPORT int DLLCALL tjEncodeYUV2(tjhandle handle, 1518 unsigned char *srcBuf, int width, int pitch, int height, int pixelFormat, 1519 unsigned char *dstBuf, int subsamp, int flags); 1520 1521DLLEXPORT int DLLCALL tjDecompressHeader(tjhandle handle, 1522 unsigned char *jpegBuf, unsigned long jpegSize, int *width, int *height); 1523 1524DLLEXPORT int DLLCALL tjDecompressHeader2(tjhandle handle, 1525 unsigned char *jpegBuf, unsigned long jpegSize, int *width, int *height, 1526 int *jpegSubsamp); 1527 1528DLLEXPORT int DLLCALL tjDecompress(tjhandle handle, 1529 unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf, 1530 int width, int pitch, int height, int pixelSize, int flags); 1531 1532DLLEXPORT int DLLCALL tjDecompressToYUV(tjhandle handle, 1533 unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf, 1534 int flags); 1535 1536 1537/** 1538 * @} 1539 */ 1540 1541#ifdef __cplusplus 1542} 1543#endif 1544 1545#endif 1546