2 * Copyright (C)2009-2015, 2017 D. R. Commander. All Rights Reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
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.
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.
29 #ifndef __TURBOJPEG_H__
30 #define __TURBOJPEG_H__
32 #if defined(_WIN32) && defined(DLLDEFINE)
33 #define DLLEXPORT __declspec(dllexport)
41 * @addtogroup TurboJPEG
42 * TurboJPEG API. This API provides an interface for generating, decoding, and
43 * transforming planar YUV and JPEG images in memory.
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.
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.
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.
79 * The number of chrominance subsampling options
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".
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
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.
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.
111 * Grayscale. The JPEG or YUV image will contain no chrominance components.
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.
118 * @note 4:4:0 subsampling is not fully accelerated in libjpeg-turbo.
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.
130 * @note 4:1:1 subsampling is not fully accelerated in libjpeg-turbo.
136 * MCU block width (in pixels) for a given level of chrominance subsampling.
138 * - 8x8 for no subsampling or grayscale
144 static const int tjMCUWidth[TJ_NUMSAMP] = {8, 16, 16, 8, 8, 32};
147 * MCU block height (in pixels) for a given level of chrominance subsampling.
149 * - 8x8 for no subsampling or grayscale
155 static const int tjMCUHeight[TJ_NUMSAMP] = {8, 8, 16, 8, 16, 8};
159 * The number of pixel formats
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.
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.
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.
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.
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.
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.
209 * Grayscale pixel format. Each 1-byte pixel represents a luminance
210 * (brightness) level from 0 to 255.
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.
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.
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.
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.
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.
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>.
262 static const int tjRedOffset[TJ_NUMPF] = {0, 2, 0, 2, 3, 1, 0, 0, 2, 3, 1, -1};
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>.
270 static const int tjGreenOffset[TJ_NUMPF] = {1, 1, 1, 1, 2, 2, 0, 1, 1, 2, 2, -1};
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>.
277 static const int tjBlueOffset[TJ_NUMPF] = {2, 0, 2, 0, 1, 3, 0, 2, 0, 1, 3, -1};
280 * Pixel size (in bytes) for a given pixel format.
282 static const int tjPixelSize[TJ_NUMPF] = {3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 4, 4};
286 * The number of JPEG colorspaces
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.
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.
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.
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.
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.
348 * The uncompressed source/destination image is stored in bottom-up (Windows,
349 * OpenGL) order, not top-down (X11) order.
351 #define TJFLAG_BOTTOMUP 2
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.
359 #define TJFLAG_FASTUPSAMPLE 256
361 * Disable buffer (re)allocation. If passed to one of the JPEG compression or
362 * transform functions, this flag will cause those functions to generate an
363 * error if the JPEG image buffer is invalid or too small rather than
364 * attempting to allocate or reallocate that buffer. This reproduces the
365 * behavior of earlier versions of TurboJPEG.
367 #define TJFLAG_NOREALLOC 1024
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.
376 #define TJFLAG_FASTDCT 2048
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.
385 #define TJFLAG_ACCURATEDCT 4096
389 * The number of transform operations
394 * Transform operations for #tjTransform()
399 * Do not transform the position of the image pixels
403 * Flip (mirror) image horizontally. This transform is imperfect if there
404 * are any partial MCU blocks on the right edge (see #TJXOPT_PERFECT.)
408 * Flip (mirror) image vertically. This transform is imperfect if there are
409 * any partial MCU blocks on the bottom edge (see #TJXOPT_PERFECT.)
413 * Transpose image (flip/mirror along upper left to lower right axis.) This
414 * transform is always perfect.
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.)
424 * Rotate image clockwise by 90 degrees. This transform is imperfect if
425 * there are any partial MCU blocks on the bottom edge (see
430 * Rotate image 180 degrees. This transform is imperfect if there are any
431 * partial MCU blocks in the image (see #TJXOPT_PERFECT.)
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
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.
455 #define TJXOPT_PERFECT 1
457 * This option will cause #tjTransform() to discard any partial MCU blocks that
458 * cannot be transformed.
460 #define TJXOPT_TRIM 2
462 * This option will enable lossless cropping. See #tjTransform() for more
465 #define TJXOPT_CROP 4
467 * This option will discard the color data in the input image and produce
468 * a grayscale output image.
470 #define TJXOPT_GRAY 8
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
477 #define TJXOPT_NOOUTPUT 16
501 * The left boundary of the cropping region. This must be evenly divisible
502 * by the MCU block width (see #tjMCUWidth.)
506 * The upper boundary of the cropping region. This must be evenly divisible
507 * by the MCU block height (see #tjMCUHeight.)
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.
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.
525 typedef struct tjtransform
532 * One of the @ref TJXOP "transform operations"
536 * The bitwise OR of one of more of the @ref TJXOPT_CROP "transform options"
540 * Arbitrary data that can be accessed within the body of the callback
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.
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.)
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.
561 * @param planeRegion #tjregion structure containing the width and height of
562 * the component plane to which <tt>coeffs</tt> belongs
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.)
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().
572 * @param transform a pointer to a #tjtransform structure that specifies the
573 * parameters and/or cropping region for this transform
575 * @return 0 if the callback was successful, or -1 if an error occurred.
577 int (*customFilter)(short *coeffs, tjregion arrayRegion,
578 tjregion planeRegion, int componentIndex, int transformIndex,
579 struct tjtransform *transform);
583 * TurboJPEG instance handle
585 typedef void* tjhandle;
589 * Pad the given width to the nearest 32-bit boundary
591 #define TJPAD(width) (((width)+3)&(~3))
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>.
598 #define TJSCALED(dimension, scalingFactor) ((dimension * scalingFactor.num \
599 + scalingFactor.denom - 1) / scalingFactor.denom)
608 * Create a TurboJPEG compressor instance.
610 * @return a handle to the newly-created instance, or NULL if an error
611 * occurred (see #tjGetErrorStr().)
613 DLLEXPORT tjhandle DLLCALL tjInitCompress(void);
617 * Compress an RGB, grayscale, or CMYK image into a JPEG image.
619 * @param handle a handle to a TurboJPEG compressor or transformer instance
621 * @param srcBuf pointer to an image buffer containing RGB, grayscale, or
622 * CMYK pixels to be compressed
624 * @param width width (in pixels) of the source image
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>.
634 * @param height height (in pixels) of the source image
636 * @param pixelFormat pixel format of the source image (see @ref TJPF
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
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 that it won't be.)
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.
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.
663 * @param jpegSubsamp the level of chrominance subsampling to be used when
664 * generating the JPEG image (see @ref TJSAMP
665 * "Chrominance subsampling options".)
667 * @param jpegQual the image quality of the generated JPEG image (1 = worst,
670 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
673 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
675 DLLEXPORT int DLLCALL tjCompress2(tjhandle handle, const 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);
681 * Compress a YUV planar image into a JPEG image.
683 * @param handle a handle to a TurboJPEG compressor or transformer instance
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".)
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.
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.
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.
704 * @param subsamp the level of chrominance subsampling used in the source
705 * image (see @ref TJSAMP "Chrominance subsampling options".)
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
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 that it won't be.)
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.
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.
731 * @param jpegQual the image quality of the generated JPEG image (1 = worst,
734 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
737 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
739 DLLEXPORT int DLLCALL tjCompressFromYUV(tjhandle handle,
740 const unsigned char *srcBuf, int width, int pad, int height, int subsamp,
741 unsigned char **jpegBuf, unsigned long *jpegSize, int jpegQual, int flags);
745 * Compress a set of Y, U (Cb), and V (Cr) image planes into a JPEG image.
747 * @param handle a handle to a TurboJPEG compressor or transformer instance
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"
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.
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
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.
774 * @param subsamp the level of chrominance subsampling used in the source
775 * image (see @ref TJSAMP "Chrominance subsampling options".)
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
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 that it won't be.)
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.
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.
801 * @param jpegQual the image quality of the generated JPEG image (1 = worst,
804 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
807 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
809 DLLEXPORT int DLLCALL tjCompressFromYUVPlanes(tjhandle handle,
810 const unsigned char **srcPlanes, int width, const int *strides, int height,
811 int subsamp, unsigned char **jpegBuf, unsigned long *jpegSize, int jpegQual,
816 * The maximum size of the buffer (in bytes) required to hold a JPEG image with
817 * the given parameters. The number of bytes returned by this function is
818 * larger than the size of the uncompressed source image. The reason for this
819 * is that the JPEG format uses 16-bit coefficients, and it is thus possible
820 * for a very high-quality JPEG image with very high-frequency content to
821 * expand rather than compress when converted to the JPEG format. Such images
822 * represent a very rare corner case, but since there is no way to predict the
823 * size of a JPEG image prior to compression, the corner case has to be
826 * @param width width (in pixels) of the image
828 * @param height height (in pixels) of the image
830 * @param jpegSubsamp the level of chrominance subsampling to be used when
831 * generating the JPEG image (see @ref TJSAMP
832 * "Chrominance subsampling options".)
834 * @return the maximum size of the buffer (in bytes) required to hold the
835 * image, or -1 if the arguments are out of bounds.
837 DLLEXPORT unsigned long DLLCALL tjBufSize(int width, int height,
842 * The size of the buffer (in bytes) required to hold a YUV planar image with
843 * the given parameters.
845 * @param width width (in pixels) of the image
847 * @param pad the width of each line in each plane of the image is padded to
848 * the nearest multiple of this number of bytes (must be a power of 2.)
850 * @param height height (in pixels) of the image
852 * @param subsamp level of chrominance subsampling in the image (see
853 * @ref TJSAMP "Chrominance subsampling options".)
855 * @return the size of the buffer (in bytes) required to hold the image, or
856 * -1 if the arguments are out of bounds.
858 DLLEXPORT unsigned long DLLCALL tjBufSizeYUV2(int width, int pad, int height,
863 * The size of the buffer (in bytes) required to hold a YUV image plane with
864 * the given parameters.
866 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
868 * @param width width (in pixels) of the YUV image. NOTE: this is the width of
869 * the whole image, not the plane width.
871 * @param stride bytes per line in the image plane. Setting this to 0 is the
872 * equivalent of setting it to the plane width.
874 * @param height height (in pixels) of the YUV image. NOTE: this is the height
875 * of the whole image, not the plane height.
877 * @param subsamp level of chrominance subsampling in the image (see
878 * @ref TJSAMP "Chrominance subsampling options".)
880 * @return the size of the buffer (in bytes) required to hold the YUV image
881 * plane, or -1 if the arguments are out of bounds.
883 DLLEXPORT unsigned long DLLCALL tjPlaneSizeYUV(int componentID, int width,
884 int stride, int height, int subsamp);
888 * The plane width of a YUV image plane with the given parameters. Refer to
889 * @ref YUVnotes "YUV Image Format Notes" for a description of plane width.
891 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
893 * @param width width (in pixels) of the YUV image
895 * @param subsamp level of chrominance subsampling in the image (see
896 * @ref TJSAMP "Chrominance subsampling options".)
898 * @return the plane width of a YUV image plane with the given parameters, or
899 * -1 if the arguments are out of bounds.
901 DLLEXPORT int tjPlaneWidth(int componentID, int width, int subsamp);
905 * The plane height of a YUV image plane with the given parameters. Refer to
906 * @ref YUVnotes "YUV Image Format Notes" for a description of plane height.
908 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
910 * @param height height (in pixels) of the YUV image
912 * @param subsamp level of chrominance subsampling in the image (see
913 * @ref TJSAMP "Chrominance subsampling options".)
915 * @return the plane height of a YUV image plane with the given parameters, or
916 * -1 if the arguments are out of bounds.
918 DLLEXPORT int tjPlaneHeight(int componentID, int height, int subsamp);
922 * Encode an RGB or grayscale image into a YUV planar image. This function
923 * uses the accelerated color conversion routines in the underlying
924 * codec but does not execute any of the other steps in the JPEG compression
927 * @param handle a handle to a TurboJPEG compressor or transformer instance
929 * @param srcBuf pointer to an image buffer containing RGB or grayscale pixels
932 * @param width width (in pixels) of the source image
934 * @param pitch bytes per line in the source image. Normally, this should be
935 * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or
936 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image
937 * is padded to the nearest 32-bit boundary, as is the case for Windows
938 * bitmaps. You can also be clever and use this parameter to skip lines, etc.
939 * Setting this parameter to 0 is the equivalent of setting it to
940 * <tt>width * #tjPixelSize[pixelFormat]</tt>.
942 * @param height height (in pixels) of the source image
944 * @param pixelFormat pixel format of the source image (see @ref TJPF
947 * @param dstBuf pointer to an image buffer that will receive the YUV image.
948 * Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based
949 * on the image width, height, padding, and level of chrominance subsampling.
950 * The Y, U (Cb), and V (Cr) image planes will be stored sequentially in the
951 * buffer (refer to @ref YUVnotes "YUV Image Format Notes".)
953 * @param pad the width of each line in each plane of the YUV image will be
954 * padded to the nearest multiple of this number of bytes (must be a power of
955 * 2.) To generate images suitable for X Video, <tt>pad</tt> should be set to
958 * @param subsamp the level of chrominance subsampling to be used when
959 * generating the YUV image (see @ref TJSAMP
960 * "Chrominance subsampling options".) To generate images suitable for X
961 * Video, <tt>subsamp</tt> should be set to @ref TJSAMP_420. This produces an
962 * image compatible with the I420 (AKA "YUV420P") format.
964 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
967 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
969 DLLEXPORT int DLLCALL tjEncodeYUV3(tjhandle handle,
970 const unsigned char *srcBuf, int width, int pitch, int height,
971 int pixelFormat, unsigned char *dstBuf, int pad, int subsamp, int flags);
975 * Encode an RGB or grayscale image into separate Y, U (Cb), and V (Cr) image
976 * planes. This function uses the accelerated color conversion routines in the
977 * underlying codec but does not execute any of the other steps in the JPEG
978 * compression process.
980 * @param handle a handle to a TurboJPEG compressor or transformer instance
982 * @param srcBuf pointer to an image buffer containing RGB or grayscale pixels
985 * @param width width (in pixels) of the source image
987 * @param pitch bytes per line in the source image. Normally, this should be
988 * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or
989 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image
990 * is padded to the nearest 32-bit boundary, as is the case for Windows
991 * bitmaps. You can also be clever and use this parameter to skip lines, etc.
992 * Setting this parameter to 0 is the equivalent of setting it to
993 * <tt>width * #tjPixelSize[pixelFormat]</tt>.
995 * @param height height (in pixels) of the source image
997 * @param pixelFormat pixel format of the source image (see @ref TJPF
1000 * @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
1001 * (or just a Y plane, if generating a grayscale image) that will receive the
1002 * encoded image. These planes can be contiguous or non-contiguous in memory.
1003 * Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based
1004 * on the image width, height, strides, and level of chrominance subsampling.
1005 * Refer to @ref YUVnotes "YUV Image Format Notes" for more details.
1007 * @param strides an array of integers, each specifying the number of bytes per
1008 * line in the corresponding plane of the output image. Setting the stride for
1009 * any plane to 0 is the same as setting it to the plane width (see
1010 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then
1011 * the strides for all planes will be set to their respective plane widths.
1012 * You can adjust the strides in order to add an arbitrary amount of line
1013 * padding to each plane or to encode an RGB or grayscale image into a
1014 * subregion of a larger YUV planar image.
1016 * @param subsamp the level of chrominance subsampling to be used when
1017 * generating the YUV image (see @ref TJSAMP
1018 * "Chrominance subsampling options".) To generate images suitable for X
1019 * Video, <tt>subsamp</tt> should be set to @ref TJSAMP_420. This produces an
1020 * image compatible with the I420 (AKA "YUV420P") format.
1022 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
1025 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
1027 DLLEXPORT int DLLCALL tjEncodeYUVPlanes(tjhandle handle,
1028 const unsigned char *srcBuf, int width, int pitch, int height,
1029 int pixelFormat, unsigned char **dstPlanes, int *strides, int subsamp,
1034 * Create a TurboJPEG decompressor instance.
1036 * @return a handle to the newly-created instance, or NULL if an error
1037 * occurred (see #tjGetErrorStr().)
1039 DLLEXPORT tjhandle DLLCALL tjInitDecompress(void);
1043 * Retrieve information about a JPEG image without decompressing it.
1045 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1047 * @param jpegBuf pointer to a buffer containing a JPEG image
1049 * @param jpegSize size of the JPEG image (in bytes)
1051 * @param width pointer to an integer variable that will receive the width (in
1052 * pixels) of the JPEG image
1054 * @param height pointer to an integer variable that will receive the height
1055 * (in pixels) of the JPEG image
1057 * @param jpegSubsamp pointer to an integer variable that will receive the
1058 * level of chrominance subsampling used when the JPEG image was compressed
1059 * (see @ref TJSAMP "Chrominance subsampling options".)
1061 * @param jpegColorspace pointer to an integer variable that will receive one
1062 * of the JPEG colorspace constants, indicating the colorspace of the JPEG
1063 * image (see @ref TJCS "JPEG colorspaces".)
1065 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
1067 DLLEXPORT int DLLCALL tjDecompressHeader3(tjhandle handle,
1068 const unsigned char *jpegBuf, unsigned long jpegSize, int *width,
1069 int *height, int *jpegSubsamp, int *jpegColorspace);
1073 * Returns a list of fractional scaling factors that the JPEG decompressor in
1074 * this implementation of TurboJPEG supports.
1076 * @param numscalingfactors pointer to an integer variable that will receive
1077 * the number of elements in the list
1079 * @return a pointer to a list of fractional scaling factors, or NULL if an
1080 * error is encountered (see #tjGetErrorStr().)
1082 DLLEXPORT tjscalingfactor* DLLCALL tjGetScalingFactors(int *numscalingfactors);
1086 * Decompress a JPEG image to an RGB, grayscale, or CMYK image.
1088 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1090 * @param jpegBuf pointer to a buffer containing the JPEG image to decompress
1092 * @param jpegSize size of the JPEG image (in bytes)
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.
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.
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>.
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.
1126 * @param pixelFormat pixel format of the destination image (see @ref
1127 * TJPF "Pixel formats".)
1129 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
1132 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
1134 DLLEXPORT int DLLCALL tjDecompress2(tjhandle handle,
1135 const unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf,
1136 int width, int pitch, int height, int pixelFormat, int flags);
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.
1144 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1146 * @param jpegBuf pointer to a buffer containing the JPEG image to decompress
1148 * @param jpegSize size of the JPEG image (in bytes)
1150 * @param dstBuf pointer to an image buffer that will receive the YUV image.
1151 * Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based
1152 * on the image width, height, padding, and level of subsampling. The Y,
1153 * U (Cb), and V (Cr) image planes will be stored sequentially in the buffer
1154 * (refer to @ref YUVnotes "YUV Image Format Notes".)
1156 * @param width desired width (in pixels) of the YUV image. If this is
1157 * different than the width of the JPEG image being decompressed, then
1158 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
1159 * possible image that will fit within the desired width. If <tt>width</tt> is
1160 * set to 0, then only the height will be considered when determining the
1161 * scaled image size. If the scaled width is not an even multiple of the MCU
1162 * block width (see #tjMCUWidth), then an intermediate buffer copy will be
1163 * performed within TurboJPEG.
1165 * @param pad the width of each line in each plane of the YUV image will be
1166 * padded to the nearest multiple of this number of bytes (must be a power of
1167 * 2.) To generate images suitable for X Video, <tt>pad</tt> should be set to
1170 * @param height desired height (in pixels) of the YUV image. If this is
1171 * different than the height of the JPEG image being decompressed, then
1172 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
1173 * possible image that will fit within the desired height. If <tt>height</tt>
1174 * is set to 0, then only the width will be considered when determining the
1175 * scaled image size. If the scaled height is not an even multiple of the MCU
1176 * block height (see #tjMCUHeight), then an intermediate buffer copy will be
1177 * performed within TurboJPEG.
1179 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
1182 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
1184 DLLEXPORT int DLLCALL tjDecompressToYUV2(tjhandle handle,
1185 const unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf,
1186 int width, int pad, int height, int flags);
1190 * Decompress a JPEG image into separate Y, U (Cb), and V (Cr) image
1191 * planes. This function performs JPEG decompression but leaves out the color
1192 * conversion step, so a planar YUV image is generated instead of an RGB image.
1194 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1196 * @param jpegBuf pointer to a buffer containing the JPEG image to decompress
1198 * @param jpegSize size of the JPEG image (in bytes)
1200 * @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
1201 * (or just a Y plane, if decompressing a grayscale image) that will receive
1202 * the YUV image. These planes can be contiguous or non-contiguous in memory.
1203 * Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based
1204 * on the scaled image width, scaled image height, strides, and level of
1205 * chrominance subsampling. Refer to @ref YUVnotes "YUV Image Format Notes"
1208 * @param width desired width (in pixels) of the YUV image. If this is
1209 * different than the width of the JPEG image being decompressed, then
1210 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
1211 * possible image that will fit within the desired width. If <tt>width</tt> is
1212 * set to 0, then only the height will be considered when determining the
1213 * scaled image size. If the scaled width is not an even multiple of the MCU
1214 * block width (see #tjMCUWidth), then an intermediate buffer copy will be
1215 * performed within TurboJPEG.
1217 * @param strides an array of integers, each specifying the number of bytes per
1218 * line in the corresponding plane of the output image. Setting the stride for
1219 * any plane to 0 is the same as setting it to the scaled plane width (see
1220 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then
1221 * the strides for all planes will be set to their respective scaled plane
1222 * widths. You can adjust the strides in order to add an arbitrary amount of
1223 * line padding to each plane or to decompress the JPEG image into a subregion
1224 * of a larger YUV planar image.
1226 * @param height desired height (in pixels) of the YUV image. If this is
1227 * different than the height of the JPEG image being decompressed, then
1228 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
1229 * possible image that will fit within the desired height. If <tt>height</tt>
1230 * is set to 0, then only the width will be considered when determining the
1231 * scaled image size. If the scaled height is not an even multiple of the MCU
1232 * block height (see #tjMCUHeight), then an intermediate buffer copy will be
1233 * performed within TurboJPEG.
1235 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
1238 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
1240 DLLEXPORT int DLLCALL tjDecompressToYUVPlanes(tjhandle handle,
1241 const unsigned char *jpegBuf, unsigned long jpegSize,
1242 unsigned char **dstPlanes, int width, int *strides, int height, int flags);
1246 * Decode a YUV planar image into an RGB or grayscale image. This function
1247 * uses the accelerated color conversion routines in the underlying
1248 * codec but does not execute any of the other steps in the JPEG decompression
1251 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1253 * @param srcBuf pointer to an image buffer containing a YUV planar image to be
1254 * decoded. The size of this buffer should match the value returned by
1255 * #tjBufSizeYUV2() for the given image width, height, padding, and level of
1256 * chrominance subsampling. The Y, U (Cb), and V (Cr) image planes should be
1257 * stored sequentially in the source buffer (refer to @ref YUVnotes
1258 * "YUV Image Format Notes".)
1260 * @param pad Use this parameter to specify that the width of each line in each
1261 * plane of the YUV source image is padded to the nearest multiple of this
1262 * number of bytes (must be a power of 2.)
1264 * @param subsamp the level of chrominance subsampling used in the YUV source
1265 * image (see @ref TJSAMP "Chrominance subsampling options".)
1267 * @param dstBuf pointer to an image buffer that will receive the decoded
1268 * image. This buffer should normally be <tt>pitch * height</tt> bytes in
1269 * size, but the <tt>dstBuf</tt> pointer can also be used to decode into a
1270 * specific region of a larger buffer.
1272 * @param width width (in pixels) of the source and destination images
1274 * @param pitch bytes per line in the destination image. Normally, this should
1275 * be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is
1276 * unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line
1277 * of the destination image should be padded to the nearest 32-bit boundary, as
1278 * is the case for Windows bitmaps. You can also be clever and use the pitch
1279 * parameter to skip lines, etc. Setting this parameter to 0 is the equivalent
1280 * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.
1282 * @param height height (in pixels) of the source and destination images
1284 * @param pixelFormat pixel format of the destination image (see @ref TJPF
1287 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
1290 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
1292 DLLEXPORT int DLLCALL tjDecodeYUV(tjhandle handle, const unsigned char *srcBuf,
1293 int pad, int subsamp, unsigned char *dstBuf, int width, int pitch,
1294 int height, int pixelFormat, int flags);
1298 * Decode a set of Y, U (Cb), and V (Cr) image planes into an RGB or grayscale
1299 * image. This function uses the accelerated color conversion routines in the
1300 * underlying codec but does not execute any of the other steps in the JPEG
1301 * decompression process.
1303 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1305 * @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
1306 * (or just a Y plane, if decoding a grayscale image) that contain a YUV image
1307 * to be decoded. These planes can be contiguous or non-contiguous in memory.
1308 * The size of each plane should match the value returned by #tjPlaneSizeYUV()
1309 * for the given image width, height, strides, and level of chrominance
1310 * subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" for more
1313 * @param strides an array of integers, each specifying the number of bytes per
1314 * line in the corresponding plane of the YUV source image. Setting the stride
1315 * for any plane to 0 is the same as setting it to the plane width (see
1316 * @ref YUVnotes "YUV Image Format Notes".) If <tt>strides</tt> is NULL, then
1317 * the strides for all planes will be set to their respective plane widths.
1318 * You can adjust the strides in order to specify an arbitrary amount of line
1319 * padding in each plane or to decode a subregion of a larger YUV planar image.
1321 * @param subsamp the level of chrominance subsampling used in the YUV source
1322 * image (see @ref TJSAMP "Chrominance subsampling options".)
1324 * @param dstBuf pointer to an image buffer that will receive the decoded
1325 * image. This buffer should normally be <tt>pitch * height</tt> bytes in
1326 * size, but the <tt>dstBuf</tt> pointer can also be used to decode into a
1327 * specific region of a larger buffer.
1329 * @param width width (in pixels) of the source and destination images
1331 * @param pitch bytes per line in the destination image. Normally, this should
1332 * be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is
1333 * unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line
1334 * of the destination image should be padded to the nearest 32-bit boundary, as
1335 * is the case for Windows bitmaps. You can also be clever and use the pitch
1336 * parameter to skip lines, etc. Setting this parameter to 0 is the equivalent
1337 * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.
1339 * @param height height (in pixels) of the source and destination images
1341 * @param pixelFormat pixel format of the destination image (see @ref TJPF
1344 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
1347 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
1349 DLLEXPORT int DLLCALL tjDecodeYUVPlanes(tjhandle handle,
1350 const unsigned char **srcPlanes, const int *strides, int subsamp,
1351 unsigned char *dstBuf, int width, int pitch, int height, int pixelFormat,
1356 * Create a new TurboJPEG transformer instance.
1358 * @return a handle to the newly-created instance, or NULL if an error
1359 * occurred (see #tjGetErrorStr().)
1361 DLLEXPORT tjhandle DLLCALL tjInitTransform(void);
1365 * Losslessly transform a JPEG image into another JPEG image. Lossless
1366 * transforms work by moving the raw DCT coefficients from one JPEG image
1367 * structure to another without altering the values of the coefficients. While
1368 * this is typically faster than decompressing the image, transforming it, and
1369 * re-compressing it, lossless transforms are not free. Each lossless
1370 * transform requires reading and performing Huffman decoding on all of the
1371 * coefficients in the source image, regardless of the size of the destination
1372 * image. Thus, this function provides a means of generating multiple
1373 * transformed images from the same source or applying multiple
1374 * transformations simultaneously, in order to eliminate the need to read the
1375 * source coefficients multiple times.
1377 * @param handle a handle to a TurboJPEG transformer instance
1379 * @param jpegBuf pointer to a buffer containing the JPEG source image to
1382 * @param jpegSize size of the JPEG source image (in bytes)
1384 * @param n the number of transformed JPEG images to generate
1386 * @param dstBufs pointer to an array of n image buffers. <tt>dstBufs[i]</tt>
1387 * will receive a JPEG image that has been transformed using the parameters in
1388 * <tt>transforms[i]</tt>. TurboJPEG has the ability to reallocate the JPEG
1389 * buffer to accommodate the size of the JPEG image. Thus, you can choose to:
1390 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
1391 * let TurboJPEG grow the buffer as needed,
1392 * -# set <tt>dstBufs[i]</tt> to NULL to tell TurboJPEG to allocate the buffer
1394 * -# pre-allocate the buffer to a "worst case" size determined by calling
1395 * #tjBufSize() with the transformed or cropped width and height. Under normal
1396 * circumstances, this should ensure that the buffer never has to be
1397 * re-allocated (setting #TJFLAG_NOREALLOC guarantees that it won't be.) Note,
1398 * however, that there are some rare cases (such as transforming images with a
1399 * large amount of embedded EXIF or ICC profile data) in which the output image
1400 * will be larger than the worst-case size, and #TJFLAG_NOREALLOC cannot be
1401 * used in those cases.
1403 * If you choose option 1, <tt>dstSizes[i]</tt> should be set to the size of
1404 * your pre-allocated buffer. In any case, unless you have set
1405 * #TJFLAG_NOREALLOC, you should always check <tt>dstBufs[i]</tt> upon return
1406 * from this function, as it may have changed.
1408 * @param dstSizes pointer to an array of n unsigned long variables that will
1409 * receive the actual sizes (in bytes) of each transformed JPEG image. If
1410 * <tt>dstBufs[i]</tt> points to a pre-allocated buffer, then
1411 * <tt>dstSizes[i]</tt> should be set to the size of the buffer. Upon return,
1412 * <tt>dstSizes[i]</tt> will contain the size of the JPEG image (in bytes.)
1414 * @param transforms pointer to an array of n #tjtransform structures, each of
1415 * which specifies the transform parameters and/or cropping region for the
1416 * corresponding transformed output image.
1418 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
1421 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
1423 DLLEXPORT int DLLCALL tjTransform(tjhandle handle,
1424 const unsigned char *jpegBuf, unsigned long jpegSize, int n,
1425 unsigned char **dstBufs, unsigned long *dstSizes, tjtransform *transforms,
1430 * Destroy a TurboJPEG compressor, decompressor, or transformer instance.
1432 * @param handle a handle to a TurboJPEG compressor, decompressor or
1433 * transformer instance
1435 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
1437 DLLEXPORT int DLLCALL tjDestroy(tjhandle handle);
1441 * Allocate an image buffer for use with TurboJPEG. You should always use
1442 * this function to allocate the JPEG destination buffer(s) for the compression
1443 * and transform functions unless you are disabling automatic buffer
1444 * (re)allocation (by setting #TJFLAG_NOREALLOC.)
1446 * @param bytes the number of bytes to allocate
1448 * @return a pointer to a newly-allocated buffer with the specified number of
1453 DLLEXPORT unsigned char* DLLCALL tjAlloc(int bytes);
1457 * Free an image buffer previously allocated by TurboJPEG. You should always
1458 * use this function to free JPEG destination buffer(s) that were automatically
1459 * (re)allocated by the compression and transform functions or that were
1460 * manually allocated using #tjAlloc().
1462 * @param buffer address of the buffer to free
1466 DLLEXPORT void DLLCALL tjFree(unsigned char *buffer);
1470 * Returns a descriptive error message explaining why the last command failed.
1472 * @return a descriptive error message explaining why the last command failed.
1474 DLLEXPORT char* DLLCALL tjGetErrorStr(void);
1477 /* Deprecated functions and macros */
1478 #define TJFLAG_FORCEMMX 8
1479 #define TJFLAG_FORCESSE 16
1480 #define TJFLAG_FORCESSE2 32
1481 #define TJFLAG_FORCESSE3 128
1484 /* Backward compatibility functions and macros (nothing to see here) */
1485 #define NUMSUBOPT TJ_NUMSAMP
1486 #define TJ_444 TJSAMP_444
1487 #define TJ_422 TJSAMP_422
1488 #define TJ_420 TJSAMP_420
1489 #define TJ_411 TJSAMP_420
1490 #define TJ_GRAYSCALE TJSAMP_GRAY
1493 #define TJ_BOTTOMUP TJFLAG_BOTTOMUP
1494 #define TJ_FORCEMMX TJFLAG_FORCEMMX
1495 #define TJ_FORCESSE TJFLAG_FORCESSE
1496 #define TJ_FORCESSE2 TJFLAG_FORCESSE2
1497 #define TJ_ALPHAFIRST 64
1498 #define TJ_FORCESSE3 TJFLAG_FORCESSE3
1499 #define TJ_FASTUPSAMPLE TJFLAG_FASTUPSAMPLE
1502 DLLEXPORT unsigned long DLLCALL TJBUFSIZE(int width, int height);
1504 DLLEXPORT unsigned long DLLCALL TJBUFSIZEYUV(int width, int height,
1507 DLLEXPORT unsigned long DLLCALL tjBufSizeYUV(int width, int height,
1510 DLLEXPORT int DLLCALL tjCompress(tjhandle handle, unsigned char *srcBuf,
1511 int width, int pitch, int height, int pixelSize, unsigned char *dstBuf,
1512 unsigned long *compressedSize, int jpegSubsamp, int jpegQual, int flags);
1514 DLLEXPORT int DLLCALL tjEncodeYUV(tjhandle handle,
1515 unsigned char *srcBuf, int width, int pitch, int height, int pixelSize,
1516 unsigned char *dstBuf, int subsamp, int flags);
1518 DLLEXPORT int DLLCALL tjEncodeYUV2(tjhandle handle,
1519 unsigned char *srcBuf, int width, int pitch, int height, int pixelFormat,
1520 unsigned char *dstBuf, int subsamp, int flags);
1522 DLLEXPORT int DLLCALL tjDecompressHeader(tjhandle handle,
1523 unsigned char *jpegBuf, unsigned long jpegSize, int *width, int *height);
1525 DLLEXPORT int DLLCALL tjDecompressHeader2(tjhandle handle,
1526 unsigned char *jpegBuf, unsigned long jpegSize, int *width, int *height,
1529 DLLEXPORT int DLLCALL tjDecompress(tjhandle handle,
1530 unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf,
1531 int width, int pitch, int height, int pixelSize, int flags);
1533 DLLEXPORT int DLLCALL tjDecompressToYUV(tjhandle handle,
1534 unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf,