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