1 /* 2 * Copyright (C)2009-2015 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 /** 95 * 4:4:4 chrominance subsampling (no chrominance subsampling). The JPEG or 96 * YUV image will contain one chrominance component for every pixel in the 97 * source image. 98 */ 99 TJSAMP_444=0, 100 /** 101 * 4:2:2 chrominance subsampling. The JPEG or YUV image will contain one 102 * chrominance component for every 2x1 block of pixels in the source image. 103 */ 104 TJSAMP_422, 105 /** 106 * 4:2:0 chrominance subsampling. The JPEG or YUV image will contain one 107 * chrominance component for every 2x2 block of pixels in the source image. 108 */ 109 TJSAMP_420, 110 /** 111 * Grayscale. The JPEG or YUV image will contain no chrominance components. 112 */ 113 TJSAMP_GRAY, 114 /** 115 * 4:4:0 chrominance subsampling. The JPEG or YUV image will contain one 116 * chrominance component for every 1x2 block of pixels in the source image. 117 * 118 * @note 4:4:0 subsampling is not fully accelerated in libjpeg-turbo. 119 */ 120 TJSAMP_440, 121 /** 122 * 4:1:1 chrominance subsampling. The JPEG or YUV image will contain one 123 * chrominance component for every 4x1 block of pixels in the source image. 124 * JPEG images compressed with 4:1:1 subsampling will be almost exactly the 125 * same size as those compressed with 4:2:0 subsampling, and in the 126 * aggregate, both subsampling methods produce approximately the same 127 * perceptual quality. However, 4:1:1 is better able to reproduce sharp 128 * horizontal features. 129 * 130 * @note 4:1:1 subsampling is not fully accelerated in libjpeg-turbo. 131 */ 132 TJSAMP_411 133 }; 134 135 /** 136 * MCU block width (in pixels) for a given level of chrominance subsampling. 137 * MCU block sizes: 138 * - 8x8 for no subsampling or grayscale 139 * - 16x8 for 4:2:2 140 * - 8x16 for 4:4:0 141 * - 16x16 for 4:2:0 142 * - 32x8 for 4:1:1 143 */ 144 static const int tjMCUWidth[TJ_NUMSAMP] = {8, 16, 16, 8, 8, 32}; 145 146 /** 147 * MCU block height (in pixels) for a given level of chrominance subsampling. 148 * MCU block sizes: 149 * - 8x8 for no subsampling or grayscale 150 * - 16x8 for 4:2:2 151 * - 8x16 for 4:4:0 152 * - 16x16 for 4:2:0 153 * - 32x8 for 4:1:1 154 */ 155 static const int tjMCUHeight[TJ_NUMSAMP] = {8, 8, 16, 8, 16, 8}; 156 157 158 /** 159 * The number of pixel formats 160 */ 161 #define TJ_NUMPF 12 162 163 /** 164 * Pixel formats 165 */ 166 enum TJPF 167 { 168 /** 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 */ 262 static 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 */ 270 static 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 */ 277 static const int tjBlueOffset[TJ_NUMPF] = {2, 0, 2, 0, 1, 3, 0, 2, 0, 1, 3, -1}; 278 279 /** 280 * Pixel size (in bytes) for a given pixel format. 281 */ 282 static const int tjPixelSize[TJ_NUMPF] = {3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 4, 4}; 283 284 285 /** 286 * The number of JPEG colorspaces 287 */ 288 #define TJ_NUMCS 5 289 290 /** 291 * JPEG colorspaces 292 */ 293 enum TJCS 294 { 295 /** 296 * RGB colorspace. When compressing the JPEG image, the R, G, and B 297 * components in the source image are reordered into image planes, but no 298 * colorspace conversion or subsampling is performed. RGB JPEG images can be 299 * decompressed to any of the extended RGB pixel formats or grayscale, but 300 * they cannot be decompressed to YUV images. 301 */ 302 TJCS_RGB=0, 303 /** 304 * YCbCr colorspace. YCbCr is not an absolute colorspace but rather a 305 * mathematical transformation of RGB designed solely for storage and 306 * transmission. YCbCr images must be converted to RGB before they can 307 * actually be displayed. In the YCbCr colorspace, the Y (luminance) 308 * component represents the black & white portion of the original image, and 309 * the Cb and Cr (chrominance) components represent the color portion of the 310 * original image. Originally, the analog equivalent of this transformation 311 * allowed the same signal to drive both black & white and color televisions, 312 * but JPEG images use YCbCr primarily because it allows the color data to be 313 * optionally subsampled for the purposes of reducing bandwidth or disk 314 * space. YCbCr is the most common JPEG colorspace, and YCbCr JPEG images 315 * can be compressed from and decompressed to any of the extended RGB pixel 316 * formats or grayscale, or they can be decompressed to YUV planar images. 317 */ 318 TJCS_YCbCr, 319 /** 320 * Grayscale colorspace. The JPEG image retains only the luminance data (Y 321 * component), and any color data from the source image is discarded. 322 * Grayscale JPEG images can be compressed from and decompressed to any of 323 * the extended RGB pixel formats or grayscale, or they can be decompressed 324 * to YUV planar images. 325 */ 326 TJCS_GRAY, 327 /** 328 * CMYK colorspace. When compressing the JPEG image, the C, M, Y, and K 329 * components in the source image are reordered into image planes, but no 330 * colorspace conversion or subsampling is performed. CMYK JPEG images can 331 * only be decompressed to CMYK pixels. 332 */ 333 TJCS_CMYK, 334 /** 335 * YCCK colorspace. YCCK (AKA "YCbCrK") is not an absolute colorspace but 336 * rather a mathematical transformation of CMYK designed solely for storage 337 * and transmission. It is to CMYK as YCbCr is to RGB. CMYK pixels can be 338 * reversibly transformed into YCCK, and as with YCbCr, the chrominance 339 * components in the YCCK pixels can be subsampled without incurring major 340 * perceptual loss. YCCK JPEG images can only be compressed from and 341 * decompressed to CMYK pixels. 342 */ 343 TJCS_YCCK 344 }; 345 346 347 /** 348 * The uncompressed source/destination image is stored in bottom-up (Windows, 349 * OpenGL) order, not top-down (X11) order. 350 */ 351 #define TJFLAG_BOTTOMUP 2 352 /** 353 * When decompressing an image that was compressed using chrominance 354 * subsampling, use the fastest chrominance upsampling algorithm available in 355 * the underlying codec. The default is to use smooth upsampling, which 356 * creates a smooth transition between neighboring chrominance components in 357 * order to reduce upsampling artifacts in the decompressed image. 358 */ 359 #define TJFLAG_FASTUPSAMPLE 256 360 /** 361 * Disable buffer (re)allocation. If passed to #tjCompress2() or 362 * #tjTransform(), this flag will cause those functions to generate an error if 363 * the JPEG image buffer is invalid or too small rather than attempting to 364 * allocate or reallocate that buffer. This reproduces the behavior of earlier 365 * versions of TurboJPEG. 366 */ 367 #define TJFLAG_NOREALLOC 1024 368 /** 369 * Use the fastest DCT/IDCT algorithm available in the underlying codec. The 370 * default if this flag is not specified is implementation-specific. For 371 * example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast 372 * algorithm by default when compressing, because this has been shown to have 373 * only a very slight effect on accuracy, but it uses the accurate algorithm 374 * when decompressing, because this has been shown to have a larger effect. 375 */ 376 #define TJFLAG_FASTDCT 2048 377 /** 378 * Use the most accurate DCT/IDCT algorithm available in the underlying codec. 379 * The default if this flag is not specified is implementation-specific. For 380 * example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast 381 * algorithm by default when compressing, because this has been shown to have 382 * only a very slight effect on accuracy, but it uses the accurate algorithm 383 * when decompressing, because this has been shown to have a larger effect. 384 */ 385 #define TJFLAG_ACCURATEDCT 4096 386 387 388 /** 389 * The number of transform operations 390 */ 391 #define TJ_NUMXOP 8 392 393 /** 394 * Transform operations for #tjTransform() 395 */ 396 enum TJXOP 397 { 398 /** 399 * Do not transform the position of the image pixels 400 */ 401 TJXOP_NONE=0, 402 /** 403 * Flip (mirror) image horizontally. This transform is imperfect if there 404 * are any partial MCU blocks on the right edge (see #TJXOPT_PERFECT.) 405 */ 406 TJXOP_HFLIP, 407 /** 408 * Flip (mirror) image vertically. This transform is imperfect if there are 409 * any partial MCU blocks on the bottom edge (see #TJXOPT_PERFECT.) 410 */ 411 TJXOP_VFLIP, 412 /** 413 * Transpose image (flip/mirror along upper left to lower right axis.) This 414 * transform is always perfect. 415 */ 416 TJXOP_TRANSPOSE, 417 /** 418 * Transverse transpose image (flip/mirror along upper right to lower left 419 * axis.) This transform is imperfect if there are any partial MCU blocks in 420 * the image (see #TJXOPT_PERFECT.) 421 */ 422 TJXOP_TRANSVERSE, 423 /** 424 * Rotate image clockwise by 90 degrees. This transform is imperfect if 425 * there are any partial MCU blocks on the bottom edge (see 426 * #TJXOPT_PERFECT.) 427 */ 428 TJXOP_ROT90, 429 /** 430 * Rotate image 180 degrees. This transform is imperfect if there are any 431 * partial MCU blocks in the image (see #TJXOPT_PERFECT.) 432 */ 433 TJXOP_ROT180, 434 /** 435 * Rotate image counter-clockwise by 90 degrees. This transform is imperfect 436 * if there are any partial MCU blocks on the right edge (see 437 * #TJXOPT_PERFECT.) 438 */ 439 TJXOP_ROT270 440 }; 441 442 443 /** 444 * This option will cause #tjTransform() to return an error if the transform is 445 * not perfect. Lossless transforms operate on MCU blocks, whose size depends 446 * on the level of chrominance subsampling used (see #tjMCUWidth 447 * and #tjMCUHeight.) If the image's width or height is not evenly divisible 448 * by the MCU block size, then there will be partial MCU blocks on the right 449 * and/or bottom edges. It is not possible to move these partial MCU blocks to 450 * the top or left of the image, so any transform that would require that is 451 * "imperfect." If this option is not specified, then any partial MCU blocks 452 * that cannot be transformed will be left in place, which will create 453 * odd-looking strips on the right or bottom edge of the image. 454 */ 455 #define TJXOPT_PERFECT 1 456 /** 457 * This option will cause #tjTransform() to discard any partial MCU blocks that 458 * cannot be transformed. 459 */ 460 #define TJXOPT_TRIM 2 461 /** 462 * This option will enable lossless cropping. See #tjTransform() for more 463 * information. 464 */ 465 #define TJXOPT_CROP 4 466 /** 467 * This option will discard the color data in the input image and produce 468 * a grayscale output image. 469 */ 470 #define TJXOPT_GRAY 8 471 /** 472 * This option will prevent #tjTransform() from outputting a JPEG image for 473 * this particular transform (this can be used in conjunction with a custom 474 * filter to capture the transformed DCT coefficients without transcoding 475 * them.) 476 */ 477 #define TJXOPT_NOOUTPUT 16 478 479 480 /** 481 * Scaling factor 482 */ 483 typedef struct 484 { 485 /** 486 * Numerator 487 */ 488 int num; 489 /** 490 * Denominator 491 */ 492 int denom; 493 } tjscalingfactor; 494 495 /** 496 * Cropping region 497 */ 498 typedef struct 499 { 500 /** 501 * The left boundary of the cropping region. This must be evenly divisible 502 * by the MCU block width (see #tjMCUWidth.) 503 */ 504 int x; 505 /** 506 * The upper boundary of the cropping region. This must be evenly divisible 507 * by the MCU block height (see #tjMCUHeight.) 508 */ 509 int y; 510 /** 511 * The width of the cropping region. Setting this to 0 is the equivalent of 512 * setting it to the width of the source JPEG image - x. 513 */ 514 int w; 515 /** 516 * The height of the cropping region. Setting this to 0 is the equivalent of 517 * setting it to the height of the source JPEG image - y. 518 */ 519 int h; 520 } tjregion; 521 522 /** 523 * Lossless transform 524 */ 525 typedef struct tjtransform 526 { 527 /** 528 * Cropping region 529 */ 530 tjregion r; 531 /** 532 * One of the @ref TJXOP "transform operations" 533 */ 534 int op; 535 /** 536 * The bitwise OR of one of more of the @ref TJXOPT_CROP "transform options" 537 */ 538 int options; 539 /** 540 * Arbitrary data that can be accessed within the body of the callback 541 * function 542 */ 543 void *data; 544 /** 545 * A callback function that can be used to modify the DCT coefficients 546 * after they are losslessly transformed but before they are transcoded to a 547 * new JPEG image. This allows for custom filters or other transformations 548 * to be applied in the frequency domain. 549 * 550 * @param coeffs pointer to an array of transformed DCT coefficients. (NOTE: 551 * this pointer is not guaranteed to be valid once the callback returns, so 552 * applications wishing to hand off the DCT coefficients to another function 553 * or library should make a copy of them within the body of the callback.) 554 * 555 * @param arrayRegion #tjregion structure containing the width and height of 556 * the array pointed to by <tt>coeffs</tt> as well as its offset relative to 557 * the component plane. TurboJPEG implementations may choose to split each 558 * component plane into multiple DCT coefficient arrays and call the callback 559 * function once for each array. 560 * 561 * @param planeRegion #tjregion structure containing the width and height of 562 * the component plane to which <tt>coeffs</tt> belongs 563 * 564 * @param componentID ID number of the component plane to which 565 * <tt>coeffs</tt> belongs (Y, Cb, and Cr have, respectively, ID's of 0, 1, 566 * and 2 in typical JPEG images.) 567 * 568 * @param transformID ID number of the transformed image to which 569 * <tt>coeffs</tt> belongs. This is the same as the index of the transform 570 * in the <tt>transforms</tt> array that was passed to #tjTransform(). 571 * 572 * @param transform a pointer to a #tjtransform structure that specifies the 573 * parameters and/or cropping region for this transform 574 * 575 * @return 0 if the callback was successful, or -1 if an error occurred. 576 */ 577 int (*customFilter)(short *coeffs, tjregion arrayRegion, 578 tjregion planeRegion, int componentIndex, int transformIndex, 579 struct tjtransform *transform); 580 } tjtransform; 581 582 /** 583 * TurboJPEG instance handle 584 */ 585 typedef void* tjhandle; 586 587 588 /** 589 * Pad the given width to the nearest 32-bit boundary 590 */ 591 #define TJPAD(width) (((width)+3)&(~3)) 592 593 /** 594 * Compute the scaled value of <tt>dimension</tt> using the given scaling 595 * factor. This macro performs the integer equivalent of <tt>ceil(dimension * 596 * scalingFactor)</tt>. 597 */ 598 #define TJSCALED(dimension, scalingFactor) ((dimension * scalingFactor.num \ 599 + scalingFactor.denom - 1) / scalingFactor.denom) 600 601 602 #ifdef __cplusplus 603 extern "C" { 604 #endif 605 606 607 /** 608 * Create a TurboJPEG compressor instance. 609 * 610 * @return a handle to the newly-created instance, or NULL if an error 611 * occurred (see #tjGetErrorStr().) 612 */ 613 DLLEXPORT tjhandle DLLCALL tjInitCompress(void); 614 615 616 /** 617 * Compress an RGB, grayscale, or CMYK image into a JPEG image. 618 * 619 * @param handle a handle to a TurboJPEG compressor or transformer instance 620 * 621 * @param srcBuf pointer to an image buffer containing RGB, grayscale, or 622 * CMYK pixels to be compressed. This buffer is not modified. 623 * 624 * @param width width (in pixels) of the source image 625 * 626 * @param pitch bytes per line in the source image. Normally, this should be 627 * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or 628 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image 629 * is padded to the nearest 32-bit boundary, as is the case for Windows 630 * bitmaps. You can also be clever and use this parameter to skip lines, etc. 631 * Setting this parameter to 0 is the equivalent of setting it to 632 * <tt>width * #tjPixelSize[pixelFormat]</tt>. 633 * 634 * @param height height (in pixels) of the source image 635 * 636 * @param pixelFormat pixel format of the source image (see @ref TJPF 637 * "Pixel formats".) 638 * 639 * @param jpegBuf address of a pointer to an image buffer that will receive the 640 * JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer 641 * to accommodate the size of the JPEG image. Thus, you can choose to: 642 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and 643 * let TurboJPEG grow the buffer as needed, 644 * -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer 645 * for you, or 646 * -# pre-allocate the buffer to a "worst case" size determined by calling 647 * #tjBufSize(). This should ensure that the buffer never has to be 648 * re-allocated (setting #TJFLAG_NOREALLOC guarantees this.) 649 * . 650 * If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your 651 * pre-allocated buffer. In any case, unless you have set #TJFLAG_NOREALLOC, 652 * you should always check <tt>*jpegBuf</tt> upon return from this function, as 653 * it may have changed. 654 * 655 * @param jpegSize pointer to an unsigned long variable that holds the size of 656 * the JPEG image buffer. If <tt>*jpegBuf</tt> points to a pre-allocated 657 * buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer. 658 * Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in 659 * bytes.) If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being 660 * reused from a previous call to one of the JPEG compression functions, then 661 * <tt>*jpegSize</tt> is ignored. 662 * 663 * @param jpegSubsamp the level of chrominance subsampling to be used when 664 * generating the JPEG image (see @ref TJSAMP 665 * "Chrominance subsampling options".) 666 * 667 * @param jpegQual the image quality of the generated JPEG image (1 = worst, 668 * 100 = best) 669 * 670 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP 671 * "flags" 672 * 673 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 674 */ 675 DLLEXPORT int DLLCALL tjCompress2(tjhandle handle, unsigned char *srcBuf, 676 int width, int pitch, int height, int pixelFormat, unsigned char **jpegBuf, 677 unsigned long *jpegSize, int jpegSubsamp, int jpegQual, int flags); 678 679 680 /** 681 * Compress a YUV planar image into a JPEG image. 682 * 683 * @param handle a handle to a TurboJPEG compressor or transformer instance 684 * 685 * @param srcBuf pointer to an image buffer containing a YUV planar image to be 686 * compressed. The size of this buffer should match the value returned by 687 * #tjBufSizeYUV2() for the given image width, height, padding, and level of 688 * chrominance subsampling. The Y, U (Cb), and V (Cr) image planes should be 689 * stored sequentially in the source buffer (refer to @ref YUVnotes 690 * "YUV Image Format Notes".) This buffer is not modified. 691 * 692 * @param width width (in pixels) of the source image. If the width is not an 693 * even multiple of the MCU block width (see #tjMCUWidth), then an intermediate 694 * buffer copy will be performed within TurboJPEG. 695 * 696 * @param pad the line padding used in the source image. For instance, if each 697 * line in each plane of the YUV image is padded to the nearest multiple of 4 698 * bytes, then <tt>pad</tt> should be set to 4. 699 * 700 * @param height height (in pixels) of the source image. If the height is not 701 * an even multiple of the MCU block height (see #tjMCUHeight), then an 702 * intermediate buffer copy will be performed within TurboJPEG. 703 * 704 * @param subsamp the level of chrominance subsampling used in the source 705 * image (see @ref TJSAMP "Chrominance subsampling options".) 706 * 707 * @param jpegBuf address of a pointer to an image buffer that will receive the 708 * JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to 709 * accommodate the size of the JPEG image. Thus, you can choose to: 710 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and 711 * let TurboJPEG grow the buffer as needed, 712 * -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer 713 * for you, or 714 * -# pre-allocate the buffer to a "worst case" size determined by calling 715 * #tjBufSize(). This should ensure that the buffer never has to be 716 * re-allocated (setting #TJFLAG_NOREALLOC guarantees this.) 717 * . 718 * If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your 719 * pre-allocated buffer. In any case, unless you have set #TJFLAG_NOREALLOC, 720 * you should always check <tt>*jpegBuf</tt> upon return from this function, as 721 * it may have changed. 722 * 723 * @param jpegSize pointer to an unsigned long variable that holds the size of 724 * the JPEG image buffer. If <tt>*jpegBuf</tt> points to a pre-allocated 725 * buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer. 726 * Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in 727 * bytes.) If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being 728 * reused from a previous call to one of the JPEG compression functions, then 729 * <tt>*jpegSize</tt> is ignored. 730 * 731 * @param jpegQual the image quality of the generated JPEG image (1 = worst, 732 * 100 = best) 733 * 734 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP 735 * "flags" 736 * 737 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 738 */ 739 DLLEXPORT int DLLCALL tjCompressFromYUV(tjhandle handle, unsigned char *srcBuf, 740 int width, int pad, int height, int subsamp, unsigned char **jpegBuf, 741 unsigned long *jpegSize, int jpegQual, int flags); 742 743 744 /** 745 * Compress a set of Y, U (Cb), and V (Cr) image planes into a JPEG image. 746 * 747 * @param handle a handle to a TurboJPEG compressor or transformer instance 748 * 749 * @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes 750 * (or just a Y plane, if compressing a grayscale image) that contain a YUV 751 * image to be compressed. These planes can be contiguous or non-contiguous in 752 * memory. The size of each plane should match the value returned by 753 * #tjPlaneSizeYUV() for the given image width, height, strides, and level of 754 * chrominance subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" 755 * for more details. These image planes are not modified. 756 * 757 * @param width width (in pixels) of the source image. If the width is not an 758 * even multiple of the MCU block width (see #tjMCUWidth), then an intermediate 759 * buffer copy will be performed within TurboJPEG. 760 * 761 * @param strides an array of integers, each specifying the number of bytes per 762 * line in the corresponding plane of the YUV source image. Setting the stride 763 * for any plane to 0 is the same as setting it to the plane width (see 764 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then 765 * the strides for all planes will be set to their respective plane widths. 766 * You can adjust the strides in order to specify an arbitrary amount of line 767 * padding in each plane or to create a JPEG image from a subregion of a larger 768 * YUV planar image. 769 * 770 * @param height height (in pixels) of the source image. If the height is not 771 * an even multiple of the MCU block height (see #tjMCUHeight), then an 772 * intermediate buffer copy will be performed within TurboJPEG. 773 * 774 * @param subsamp the level of chrominance subsampling used in the source 775 * image (see @ref TJSAMP "Chrominance subsampling options".) 776 * 777 * @param jpegBuf address of a pointer to an image buffer that will receive the 778 * JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to 779 * accommodate the size of the JPEG image. Thus, you can choose to: 780 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and 781 * let TurboJPEG grow the buffer as needed, 782 * -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer 783 * for you, or 784 * -# pre-allocate the buffer to a "worst case" size determined by calling 785 * #tjBufSize(). This should ensure that the buffer never has to be 786 * re-allocated (setting #TJFLAG_NOREALLOC guarantees this.) 787 * . 788 * If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your 789 * pre-allocated buffer. In any case, unless you have set #TJFLAG_NOREALLOC, 790 * you should always check <tt>*jpegBuf</tt> upon return from this function, as 791 * it may have changed. 792 * 793 * @param jpegSize pointer to an unsigned long variable that holds the size of 794 * the JPEG image buffer. If <tt>*jpegBuf</tt> points to a pre-allocated 795 * buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer. 796 * Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in 797 * bytes.) If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being 798 * reused from a previous call to one of the JPEG compression functions, then 799 * <tt>*jpegSize</tt> is ignored. 800 * 801 * @param jpegQual the image quality of the generated JPEG image (1 = worst, 802 * 100 = best) 803 * 804 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP 805 * "flags" 806 * 807 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 808 */ 809 DLLEXPORT int DLLCALL tjCompressFromYUVPlanes(tjhandle handle, 810 unsigned char **srcPlanes, int width, int *strides, int height, int subsamp, 811 unsigned char **jpegBuf, unsigned long *jpegSize, int jpegQual, 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 */ 836 DLLEXPORT 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 */ 857 DLLEXPORT 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 */ 882 DLLEXPORT 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 */ 900 DLLEXPORT 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 */ 917 DLLEXPORT 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. This buffer is not modified. 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_BOTTOMUP 964 * "flags" 965 * 966 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 967 */ 968 DLLEXPORT int DLLCALL tjEncodeYUV3(tjhandle handle, 969 unsigned char *srcBuf, int width, int pitch, int height, int pixelFormat, 970 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. This buffer is not modified. 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_BOTTOMUP 1022 * "flags" 1023 * 1024 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1025 */ 1026 DLLEXPORT int DLLCALL tjEncodeYUVPlanes(tjhandle handle, 1027 unsigned char *srcBuf, int width, int pitch, int height, int pixelFormat, 1028 unsigned char **dstPlanes, int *strides, int subsamp, int flags); 1029 1030 1031 /** 1032 * Create a TurboJPEG decompressor instance. 1033 * 1034 * @return a handle to the newly-created instance, or NULL if an error 1035 * occurred (see #tjGetErrorStr().) 1036 */ 1037 DLLEXPORT tjhandle DLLCALL tjInitDecompress(void); 1038 1039 1040 /** 1041 * Retrieve information about a JPEG image without decompressing it. 1042 * 1043 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1044 * 1045 * @param jpegBuf pointer to a buffer containing a JPEG image. This buffer is 1046 * not modified. 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 */ 1066 DLLEXPORT int DLLCALL tjDecompressHeader3(tjhandle handle, 1067 unsigned char *jpegBuf, unsigned long jpegSize, int *width, int *height, 1068 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 */ 1081 DLLEXPORT 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 * This buffer is not modified. 1091 * 1092 * @param jpegSize size of the JPEG image (in bytes) 1093 * 1094 * @param dstBuf pointer to an image buffer that will receive the decompressed 1095 * image. This buffer should normally be <tt>pitch * scaledHeight</tt> bytes 1096 * in size, where <tt>scaledHeight</tt> can be determined by calling 1097 * #TJSCALED() with the JPEG image height and one of the scaling factors 1098 * returned by #tjGetScalingFactors(). The <tt>dstBuf</tt> pointer may also be 1099 * used to decompress into a specific region of a larger buffer. 1100 * 1101 * @param width desired width (in pixels) of the destination image. If this is 1102 * different than the width of the JPEG image being decompressed, then 1103 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1104 * possible image that will fit within the desired width. If <tt>width</tt> is 1105 * set to 0, then only the height will be considered when determining the 1106 * scaled image size. 1107 * 1108 * @param pitch bytes per line in the destination image. Normally, this is 1109 * <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt> if the decompressed image 1110 * is unpadded, else <tt>#TJPAD(scaledWidth * #tjPixelSize[pixelFormat])</tt> 1111 * if each line of the decompressed image is padded to the nearest 32-bit 1112 * boundary, as is the case for Windows bitmaps. (NOTE: <tt>scaledWidth</tt> 1113 * can be determined by calling #TJSCALED() with the JPEG image width and one 1114 * of the scaling factors returned by #tjGetScalingFactors().) You can also be 1115 * clever and use the pitch parameter to skip lines, etc. Setting this 1116 * parameter to 0 is the equivalent of setting it to 1117 * <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt>. 1118 * 1119 * @param height desired height (in pixels) of the destination image. If this 1120 * is different than the height of the JPEG image being decompressed, then 1121 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1122 * possible image that will fit within the desired height. If <tt>height</tt> 1123 * is set to 0, then only the width will be considered when determining the 1124 * scaled image size. 1125 * 1126 * @param pixelFormat pixel format of the destination image (see @ref 1127 * TJPF "Pixel formats".) 1128 * 1129 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP 1130 * "flags" 1131 * 1132 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1133 */ 1134 DLLEXPORT int DLLCALL tjDecompress2(tjhandle handle, 1135 unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf, 1136 int width, int pitch, int height, int pixelFormat, int flags); 1137 1138 1139 /** 1140 * Decompress a JPEG image to a YUV planar image. This function performs JPEG 1141 * decompression but leaves out the color conversion step, so a planar YUV 1142 * image is generated instead of an RGB image. 1143 * 1144 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1145 * 1146 * @param jpegBuf pointer to a buffer containing the JPEG image to decompress. 1147 * This buffer is not modified. 1148 * 1149 * @param jpegSize size of the JPEG image (in bytes) 1150 * 1151 * @param dstBuf pointer to an image buffer that will receive the YUV image. 1152 * Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based 1153 * on the image width, height, padding, and level of subsampling. The Y, 1154 * U (Cb), and V (Cr) image planes will be stored sequentially in the buffer 1155 * (refer to @ref YUVnotes "YUV Image Format Notes".) 1156 * 1157 * @param width desired width (in pixels) of the YUV image. If this is 1158 * different than the width of the JPEG image being decompressed, then 1159 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1160 * possible image that will fit within the desired width. If <tt>width</tt> is 1161 * set to 0, then only the height will be considered when determining the 1162 * scaled image size. If the scaled width is not an even multiple of the MCU 1163 * block width (see #tjMCUWidth), then an intermediate buffer copy will be 1164 * performed within TurboJPEG. 1165 * 1166 * @param pad the width of each line in each plane of the YUV image will be 1167 * padded to the nearest multiple of this number of bytes (must be a power of 1168 * 2.) To generate images suitable for X Video, <tt>pad</tt> should be set to 1169 * 4. 1170 * 1171 * @param height desired height (in pixels) of the YUV image. If this is 1172 * different than the height of the JPEG image being decompressed, then 1173 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1174 * possible image that will fit within the desired height. If <tt>height</tt> 1175 * is set to 0, then only the width will be considered when determining the 1176 * scaled image size. If the scaled height is not an even multiple of the MCU 1177 * block height (see #tjMCUHeight), then an intermediate buffer copy will be 1178 * performed within TurboJPEG. 1179 * 1180 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP 1181 * "flags" 1182 * 1183 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1184 */ 1185 DLLEXPORT int DLLCALL tjDecompressToYUV2(tjhandle handle, 1186 unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf, 1187 int width, int pad, int height, int flags); 1188 1189 1190 /** 1191 * Decompress a JPEG image into separate Y, U (Cb), and V (Cr) image 1192 * planes. This function performs JPEG decompression but leaves out the color 1193 * conversion step, so a planar YUV image is generated instead of an RGB image. 1194 * 1195 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1196 * 1197 * @param jpegBuf pointer to a buffer containing the JPEG image to decompress. 1198 * This buffer is not modified. 1199 * 1200 * @param jpegSize size of the JPEG image (in bytes) 1201 * 1202 * @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes 1203 * (or just a Y plane, if decompressing a grayscale image) that will receive 1204 * the YUV image. These planes can be contiguous or non-contiguous in memory. 1205 * Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based 1206 * on the scaled image width, scaled image height, strides, and level of 1207 * chrominance subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" 1208 * for more details. 1209 * 1210 * @param width desired width (in pixels) of the YUV image. If this is 1211 * different than the width of the JPEG image being decompressed, then 1212 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1213 * possible image that will fit within the desired width. If <tt>width</tt> is 1214 * set to 0, then only the height will be considered when determining the 1215 * scaled image size. If the scaled width is not an even multiple of the MCU 1216 * block width (see #tjMCUWidth), then an intermediate buffer copy will be 1217 * performed within TurboJPEG. 1218 * 1219 * @param strides an array of integers, each specifying the number of bytes per 1220 * line in the corresponding plane of the output image. Setting the stride for 1221 * any plane to 0 is the same as setting it to the scaled plane width (see 1222 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then 1223 * the strides for all planes will be set to their respective scaled plane 1224 * widths. You can adjust the strides in order to add an arbitrary amount of 1225 * line padding to each plane or to decompress the JPEG image into a subregion 1226 * of a larger YUV planar image. 1227 * 1228 * @param height desired height (in pixels) of the YUV image. If this is 1229 * different than the height of the JPEG image being decompressed, then 1230 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest 1231 * possible image that will fit within the desired height. If <tt>height</tt> 1232 * is set to 0, then only the width will be considered when determining the 1233 * scaled image size. If the scaled height is not an even multiple of the MCU 1234 * block height (see #tjMCUHeight), then an intermediate buffer copy will be 1235 * performed within TurboJPEG. 1236 * 1237 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP 1238 * "flags" 1239 * 1240 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1241 */ 1242 DLLEXPORT int DLLCALL tjDecompressToYUVPlanes(tjhandle handle, 1243 unsigned char *jpegBuf, unsigned long jpegSize, unsigned char **dstPlanes, 1244 int width, int *strides, int height, int flags); 1245 1246 1247 /** 1248 * Decode a YUV planar image into an RGB or grayscale image. This function 1249 * uses the accelerated color conversion routines in the underlying 1250 * codec but does not execute any of the other steps in the JPEG decompression 1251 * process. 1252 * 1253 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1254 * 1255 * @param srcBuf pointer to an image buffer containing a YUV planar image to be 1256 * decoded. The size of this buffer should match the value returned by 1257 * #tjBufSizeYUV2() for the given image width, height, padding, and level of 1258 * chrominance subsampling. The Y, U (Cb), and V (Cr) image planes should be 1259 * stored sequentially in the source buffer (refer to @ref YUVnotes 1260 * "YUV Image Format Notes".) This buffer is not modified. 1261 * 1262 * @param pad Use this parameter to specify that the width of each line in each 1263 * plane of the YUV source image is padded to the nearest multiple of this 1264 * number of bytes (must be a power of 2.) 1265 * 1266 * @param subsamp the level of chrominance subsampling used in the YUV source 1267 * image (see @ref TJSAMP "Chrominance subsampling options".) 1268 * 1269 * @param dstBuf pointer to an image buffer that will receive the decoded 1270 * image. This buffer should normally be <tt>pitch * height</tt> bytes in 1271 * size, but the <tt>dstBuf</tt> pointer can also be used to decode into a 1272 * specific region of a larger buffer. 1273 * 1274 * @param width width (in pixels) of the source and destination images 1275 * 1276 * @param pitch bytes per line in the destination image. Normally, this should 1277 * be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is 1278 * unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line 1279 * of the destination image should be padded to the nearest 32-bit boundary, as 1280 * is the case for Windows bitmaps. You can also be clever and use the pitch 1281 * parameter to skip lines, etc. Setting this parameter to 0 is the equivalent 1282 * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>. 1283 * 1284 * @param height height (in pixels) of the source and destination images 1285 * 1286 * @param pixelFormat pixel format of the destination image (see @ref TJPF 1287 * "Pixel formats".) 1288 * 1289 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP 1290 * "flags" 1291 * 1292 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1293 */ 1294 DLLEXPORT int DLLCALL tjDecodeYUV(tjhandle handle, unsigned char *srcBuf, 1295 int pad, int subsamp, unsigned char *dstBuf, int width, int pitch, 1296 int height, int pixelFormat, int flags); 1297 1298 1299 /** 1300 * Decode a set of Y, U (Cb), and V (Cr) image planes into an RGB or grayscale 1301 * image. This function uses the accelerated color conversion routines in the 1302 * underlying codec but does not execute any of the other steps in the JPEG 1303 * decompression process. 1304 * 1305 * @param handle a handle to a TurboJPEG decompressor or transformer instance 1306 * 1307 * @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes 1308 * (or just a Y plane, if decoding a grayscale image) that contain a YUV image 1309 * to be decoded. These planes can be contiguous or non-contiguous in memory. 1310 * The size of each plane should match the value returned by #tjPlaneSizeYUV() 1311 * for the given image width, height, strides, and level of chrominance 1312 * subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" for more 1313 * details. These image planes are not modified. 1314 * 1315 * @param strides an array of integers, each specifying the number of bytes per 1316 * line in the corresponding plane of the YUV source image. Setting the stride 1317 * for any plane to 0 is the same as setting it to the plane width (see 1318 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then 1319 * the strides for all planes will be set to their respective plane widths. 1320 * You can adjust the strides in order to specify an arbitrary amount of line 1321 * padding in each plane or to decode a subregion of a larger YUV planar image. 1322 * 1323 * @param subsamp the level of chrominance subsampling used in the YUV source 1324 * image (see @ref TJSAMP "Chrominance subsampling options".) 1325 * 1326 * @param dstBuf pointer to an image buffer that will receive the decoded 1327 * image. This buffer should normally be <tt>pitch * height</tt> bytes in 1328 * size, but the <tt>dstBuf</tt> pointer can also be used to decode into a 1329 * specific region of a larger buffer. 1330 * 1331 * @param width width (in pixels) of the source and destination images 1332 * 1333 * @param pitch bytes per line in the destination image. Normally, this should 1334 * be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is 1335 * unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line 1336 * of the destination image should be padded to the nearest 32-bit boundary, as 1337 * is the case for Windows bitmaps. You can also be clever and use the pitch 1338 * parameter to skip lines, etc. Setting this parameter to 0 is the equivalent 1339 * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>. 1340 * 1341 * @param height height (in pixels) of the source and destination images 1342 * 1343 * @param pixelFormat pixel format of the destination image (see @ref TJPF 1344 * "Pixel formats".) 1345 * 1346 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP 1347 * "flags" 1348 * 1349 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1350 */ 1351 DLLEXPORT int DLLCALL tjDecodeYUVPlanes(tjhandle handle, 1352 unsigned char **srcPlanes, int *strides, int subsamp, unsigned char *dstBuf, 1353 int width, int pitch, int height, int pixelFormat, int flags); 1354 1355 1356 /** 1357 * Create a new TurboJPEG transformer instance. 1358 * 1359 * @return a handle to the newly-created instance, or NULL if an error 1360 * occurred (see #tjGetErrorStr().) 1361 */ 1362 DLLEXPORT tjhandle DLLCALL tjInitTransform(void); 1363 1364 1365 /** 1366 * Losslessly transform a JPEG image into another JPEG image. Lossless 1367 * transforms work by moving the raw DCT coefficients from one JPEG image 1368 * structure to another without altering the values of the coefficients. While 1369 * this is typically faster than decompressing the image, transforming it, and 1370 * re-compressing it, lossless transforms are not free. Each lossless 1371 * transform requires reading and performing Huffman decoding on all of the 1372 * coefficients in the source image, regardless of the size of the destination 1373 * image. Thus, this function provides a means of generating multiple 1374 * transformed images from the same source or applying multiple 1375 * transformations simultaneously, in order to eliminate the need to read the 1376 * source coefficients multiple times. 1377 * 1378 * @param handle a handle to a TurboJPEG transformer instance 1379 * 1380 * @param jpegBuf pointer to a buffer containing the JPEG source image to 1381 * transform. This buffer is not modified. 1382 * 1383 * @param jpegSize size of the JPEG source image (in bytes) 1384 * 1385 * @param n the number of transformed JPEG images to generate 1386 * 1387 * @param dstBufs pointer to an array of n image buffers. <tt>dstBufs[i]</tt> 1388 * will receive a JPEG image that has been transformed using the parameters in 1389 * <tt>transforms[i]</tt>. TurboJPEG has the ability to reallocate the JPEG 1390 * buffer to accommodate the size of the JPEG image. Thus, you can choose to: 1391 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and 1392 * let TurboJPEG grow the buffer as needed, 1393 * -# set <tt>dstBufs[i]</tt> to NULL to tell TurboJPEG to allocate the buffer 1394 * for you, or 1395 * -# pre-allocate the buffer to a "worst case" size determined by calling 1396 * #tjBufSize() with the transformed or cropped width and height. This should 1397 * ensure that the buffer never has to be re-allocated (setting 1398 * #TJFLAG_NOREALLOC guarantees this.) 1399 * . 1400 * If you choose option 1, <tt>dstSizes[i]</tt> should be set to the size of 1401 * your pre-allocated buffer. In any case, unless you have set 1402 * #TJFLAG_NOREALLOC, you should always check <tt>dstBufs[i]</tt> upon return 1403 * from this function, as it may have changed. 1404 * 1405 * @param dstSizes pointer to an array of n unsigned long variables that will 1406 * receive the actual sizes (in bytes) of each transformed JPEG image. If 1407 * <tt>dstBufs[i]</tt> points to a pre-allocated buffer, then 1408 * <tt>dstSizes[i]</tt> should be set to the size of the buffer. Upon return, 1409 * <tt>dstSizes[i]</tt> will contain the size of the JPEG image (in bytes.) 1410 * 1411 * @param transforms pointer to an array of n #tjtransform structures, each of 1412 * which specifies the transform parameters and/or cropping region for the 1413 * corresponding transformed output image. 1414 * 1415 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP 1416 * "flags" 1417 * 1418 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1419 */ 1420 DLLEXPORT int DLLCALL tjTransform(tjhandle handle, unsigned char *jpegBuf, 1421 unsigned long jpegSize, int n, unsigned char **dstBufs, 1422 unsigned long *dstSizes, tjtransform *transforms, int flags); 1423 1424 1425 /** 1426 * Destroy a TurboJPEG compressor, decompressor, or transformer instance. 1427 * 1428 * @param handle a handle to a TurboJPEG compressor, decompressor or 1429 * transformer instance 1430 * 1431 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().) 1432 */ 1433 DLLEXPORT int DLLCALL tjDestroy(tjhandle handle); 1434 1435 1436 /** 1437 * Allocate an image buffer for use with TurboJPEG. You should always use 1438 * this function to allocate the JPEG destination buffer(s) for #tjCompress2() 1439 * and #tjTransform() unless you are disabling automatic buffer 1440 * (re)allocation (by setting #TJFLAG_NOREALLOC.) 1441 * 1442 * @param bytes the number of bytes to allocate 1443 * 1444 * @return a pointer to a newly-allocated buffer with the specified number of 1445 * bytes. 1446 * 1447 * @sa tjFree() 1448 */ 1449 DLLEXPORT unsigned char* DLLCALL tjAlloc(int bytes); 1450 1451 1452 /** 1453 * Free an image buffer previously allocated by TurboJPEG. You should always 1454 * use this function to free JPEG destination buffer(s) that were automatically 1455 * (re)allocated by #tjCompress2() or #tjTransform() or that were manually 1456 * allocated using #tjAlloc(). 1457 * 1458 * @param buffer address of the buffer to free 1459 * 1460 * @sa tjAlloc() 1461 */ 1462 DLLEXPORT void DLLCALL tjFree(unsigned char *buffer); 1463 1464 1465 /** 1466 * Returns a descriptive error message explaining why the last command failed. 1467 * 1468 * @return a descriptive error message explaining why the last command failed. 1469 */ 1470 DLLEXPORT char* DLLCALL tjGetErrorStr(void); 1471 1472 1473 /* Deprecated functions and macros */ 1474 #define TJFLAG_FORCEMMX 8 1475 #define TJFLAG_FORCESSE 16 1476 #define TJFLAG_FORCESSE2 32 1477 #define TJFLAG_FORCESSE3 128 1478 1479 1480 /* Backward compatibility functions and macros (nothing to see here) */ 1481 #define NUMSUBOPT TJ_NUMSAMP 1482 #define TJ_444 TJSAMP_444 1483 #define TJ_422 TJSAMP_422 1484 #define TJ_420 TJSAMP_420 1485 #define TJ_411 TJSAMP_420 1486 #define TJ_GRAYSCALE TJSAMP_GRAY 1487 1488 #define TJ_BGR 1 1489 #define TJ_BOTTOMUP TJFLAG_BOTTOMUP 1490 #define TJ_FORCEMMX TJFLAG_FORCEMMX 1491 #define TJ_FORCESSE TJFLAG_FORCESSE 1492 #define TJ_FORCESSE2 TJFLAG_FORCESSE2 1493 #define TJ_ALPHAFIRST 64 1494 #define TJ_FORCESSE3 TJFLAG_FORCESSE3 1495 #define TJ_FASTUPSAMPLE TJFLAG_FASTUPSAMPLE 1496 #define TJ_YUV 512 1497 1498 DLLEXPORT unsigned long DLLCALL TJBUFSIZE(int width, int height); 1499 1500 DLLEXPORT unsigned long DLLCALL TJBUFSIZEYUV(int width, int height, 1501 int jpegSubsamp); 1502 1503 DLLEXPORT unsigned long DLLCALL tjBufSizeYUV(int width, int height, 1504 int subsamp); 1505 1506 DLLEXPORT int DLLCALL tjCompress(tjhandle handle, unsigned char *srcBuf, 1507 int width, int pitch, int height, int pixelSize, unsigned char *dstBuf, 1508 unsigned long *compressedSize, int jpegSubsamp, int jpegQual, int flags); 1509 1510 DLLEXPORT int DLLCALL tjEncodeYUV(tjhandle handle, 1511 unsigned char *srcBuf, int width, int pitch, int height, int pixelSize, 1512 unsigned char *dstBuf, int subsamp, int flags); 1513 1514 DLLEXPORT int DLLCALL tjEncodeYUV2(tjhandle handle, 1515 unsigned char *srcBuf, int width, int pitch, int height, int pixelFormat, 1516 unsigned char *dstBuf, int subsamp, int flags); 1517 1518 DLLEXPORT int DLLCALL tjDecompressHeader(tjhandle handle, 1519 unsigned char *jpegBuf, unsigned long jpegSize, int *width, int *height); 1520 1521 DLLEXPORT int DLLCALL tjDecompressHeader2(tjhandle handle, 1522 unsigned char *jpegBuf, unsigned long jpegSize, int *width, int *height, 1523 int *jpegSubsamp); 1524 1525 DLLEXPORT int DLLCALL tjDecompress(tjhandle handle, 1526 unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf, 1527 int width, int pitch, int height, int pixelSize, int flags); 1528 1529 DLLEXPORT int DLLCALL tjDecompressToYUV(tjhandle handle, 1530 unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf, 1531 int flags); 1532 1533 1534 /** 1535 * @} 1536 */ 1537 1538 #ifdef __cplusplus 1539 } 1540 #endif 1541 1542 #endif 1543