text: /*
   * Copyright (C)2009-2015 D. R. Commander.  All Rights Reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * - Redistributions of source code must retain the above copyright notice,
   *   this list of conditions and the following disclaimer.
   * - Redistributions in binary form must reproduce the above copyright notice,
   *   this list of conditions and the following disclaimer in the documentation
   *   and/or other materials provided with the distribution.
   * - Neither the name of the libjpeg-turbo Project nor the names of its
   *   contributors may be used to endorse or promote products derived from this
   *   software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS",
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifndef __TURBOJPEG_H__
  #define __TURBOJPEG_H__
  
  #if defined(_WIN32) && defined(DLLDEFINE)
  #define DLLEXPORT __declspec(dllexport)
  #else
  #define DLLEXPORT
  #endif
  #define DLLCALL
  
  
  /**
   * @addtogroup TurboJPEG
   * TurboJPEG API.  This API provides an interface for generating, decoding, and
   * transforming planar YUV and JPEG images in memory.
   *
   * @anchor YUVnotes
   * YUV Image Format Notes
   * ----------------------
   * Technically, the JPEG format uses the YCbCr colorspace (which is technically
   * not a colorspace but a color transform), but per the convention of the
   * digital video community, the TurboJPEG API uses "YUV" to refer to an image
   * format consisting of Y, Cb, and Cr image planes.
   *
   * Each plane is simply a 2D array of bytes, each byte representing the value
   * of one of the components (Y, Cb, or Cr) at a particular location in the
   * image.  The width and height of each plane are determined by the image
   * width, height, and level of chrominance subsampling.   The luminance plane
   * width is the image width padded to the nearest multiple of the horizontal
   * subsampling factor (2 in the case of 4:2:0 and 4:2:2, 4 in the case of
   * 4:1:1, 1 in the case of 4:4:4 or grayscale.)  Similarly, the luminance plane
   * height is the image height padded to the nearest multiple of the vertical
   * subsampling factor (2 in the case of 4:2:0 or 4:4:0, 1 in the case of 4:4:4
   * or grayscale.)  This is irrespective of any additional padding that may be
   * specified as an argument to the various YUV functions.  The chrominance
   * plane width is equal to the luminance plane width divided by the horizontal
   * subsampling factor, and the chrominance plane height is equal to the
   * luminance plane height divided by the vertical subsampling factor.
   *
   * For example, if the source image is 35 x 35 pixels and 4:2:2 subsampling is
   * used, then the luminance plane would be 36 x 35 bytes, and each of the
   * chrominance planes would be 18 x 35 bytes.  If you specify a line padding of
   * 4 bytes on top of this, then the luminance plane would be 36 x 35 bytes, and
   * each of the chrominance planes would be 20 x 35 bytes.
   *
   * @{
   */
  
  
  /**
   * The number of chrominance subsampling options
   */
  #define TJ_NUMSAMP 6
  
  /**
   * Chrominance subsampling options.
   * When pixels are converted from RGB to YCbCr (see #TJCS_YCbCr) or from CMYK
   * to YCCK (see #TJCS_YCCK) as part of the JPEG compression process, some of
   * the Cb and Cr (chrominance) components can be discarded or averaged together
   * to produce a smaller image with little perceptible loss of image clarity
   * (the human eye is more sensitive to small changes in brightness than to
   * small changes in color.)  This is called "chrominance subsampling".
   */
  enum TJSAMP
  {
    /**
     * 4:4:4 chrominance subsampling (no chrominance subsampling).  The JPEG or
     * YUV image will contain one chrominance component for every pixel in the
     * source image.
     */
    TJSAMP_444=0,
    /**
     * 4:2:2 chrominance subsampling.  The JPEG or YUV image will contain one
     * chrominance component for every 2x1 block of pixels in the source image.
     */
    TJSAMP_422,
    /**
     * 4:2:0 chrominance subsampling.  The JPEG or YUV image will contain one
     * chrominance component for every 2x2 block of pixels in the source image.
     */
    TJSAMP_420,
    /**
     * Grayscale.  The JPEG or YUV image will contain no chrominance components.
     */
    TJSAMP_GRAY,
    /**
     * 4:4:0 chrominance subsampling.  The JPEG or YUV image will contain one
     * chrominance component for every 1x2 block of pixels in the source image.
     *
     * @note 4:4:0 subsampling is not fully accelerated in libjpeg-turbo.
     */
    TJSAMP_440,
    /**
     * 4:1:1 chrominance subsampling.  The JPEG or YUV image will contain one
     * chrominance component for every 4x1 block of pixels in the source image.
     * JPEG images compressed with 4:1:1 subsampling will be almost exactly the
     * same size as those compressed with 4:2:0 subsampling, and in the
     * aggregate, both subsampling methods produce approximately the same
     * perceptual quality.  However, 4:1:1 is better able to reproduce sharp
     * horizontal features.
     *
     * @note 4:1:1 subsampling is not fully accelerated in libjpeg-turbo.
     */
    TJSAMP_411
  };
  
  /**
   * MCU block width (in pixels) for a given level of chrominance subsampling.
   * MCU block sizes:
   * - 8x8 for no subsampling or grayscale
   * - 16x8 for 4:2:2
   * - 8x16 for 4:4:0
   * - 16x16 for 4:2:0
   * - 32x8 for 4:1:1
   */
  static const int tjMCUWidth[TJ_NUMSAMP]  = {8, 16, 16, 8, 8, 32};
  
  /**
   * MCU block height (in pixels) for a given level of chrominance subsampling.
   * MCU block sizes:
   * - 8x8 for no subsampling or grayscale
   * - 16x8 for 4:2:2
   * - 8x16 for 4:4:0
   * - 16x16 for 4:2:0
   * - 32x8 for 4:1:1
   */
  static const int tjMCUHeight[TJ_NUMSAMP] = {8, 8, 16, 8, 16, 8};
  
  
  /**
   * The number of pixel formats
   */
  #define TJ_NUMPF 12
  
  /**
   * Pixel formats
   */
  enum TJPF
  {
    /**
     * RGB pixel format.  The red, green, and blue components in the image are
     * stored in 3-byte pixels in the order R, G, B from lowest to highest byte
     * address within each pixel.
     */
    TJPF_RGB=0,
    /**
     * BGR pixel format.  The red, green, and blue components in the image are
     * stored in 3-byte pixels in the order B, G, R from lowest to highest byte
     * address within each pixel.
     */
    TJPF_BGR,
    /**
     * RGBX pixel format.  The red, green, and blue components in the image are
     * stored in 4-byte pixels in the order R, G, B from lowest to highest byte
     * address within each pixel.  The X component is ignored when compressing
     * and undefined when decompressing.
     */
    TJPF_RGBX,
    /**
     * BGRX pixel format.  The red, green, and blue components in the image are
     * stored in 4-byte pixels in the order B, G, R from lowest to highest byte
     * address within each pixel.  The X component is ignored when compressing
     * and undefined when decompressing.
     */
    TJPF_BGRX,
    /**
     * XBGR pixel format.  The red, green, and blue components in the image are
     * stored in 4-byte pixels in the order R, G, B from highest to lowest byte
     * address within each pixel.  The X component is ignored when compressing
     * and undefined when decompressing.
     */
    TJPF_XBGR,
    /**
     * XRGB pixel format.  The red, green, and blue components in the image are
     * stored in 4-byte pixels in the order B, G, R from highest to lowest byte
     * address within each pixel.  The X component is ignored when compressing
     * and undefined when decompressing.
     */
    TJPF_XRGB,
    /**
     * Grayscale pixel format.  Each 1-byte pixel represents a luminance
     * (brightness) level from 0 to 255.
     */
    TJPF_GRAY,
    /**
     * RGBA pixel format.  This is the same as @ref TJPF_RGBX, except that when
     * decompressing, the X component is guaranteed to be 0xFF, which can be
     * interpreted as an opaque alpha channel.
     */
    TJPF_RGBA,
    /**
     * BGRA pixel format.  This is the same as @ref TJPF_BGRX, except that when
     * decompressing, the X component is guaranteed to be 0xFF, which can be
     * interpreted as an opaque alpha channel.
     */
    TJPF_BGRA,
    /**
     * ABGR pixel format.  This is the same as @ref TJPF_XBGR, except that when
     * decompressing, the X component is guaranteed to be 0xFF, which can be
     * interpreted as an opaque alpha channel.
     */
    TJPF_ABGR,
    /**
     * ARGB pixel format.  This is the same as @ref TJPF_XRGB, except that when
     * decompressing, the X component is guaranteed to be 0xFF, which can be
     * interpreted as an opaque alpha channel.
     */
    TJPF_ARGB,
    /**
     * CMYK pixel format.  Unlike RGB, which is an additive color model used
     * primarily for display, CMYK (Cyan/Magenta/Yellow/Key) is a subtractive
     * color model used primarily for printing.  In the CMYK color model, the
     * value of each color component typically corresponds to an amount of cyan,
     * magenta, yellow, or black ink that is applied to a white background.  In
     * order to convert between CMYK and RGB, it is necessary to use a color
     * management system (CMS.)  A CMS will attempt to map colors within the
     * printer's gamut to perceptually similar colors in the display's gamut and
     * vice versa, but the mapping is typically not 1:1 or reversible, nor can it
     * be defined with a simple formula.  Thus, such a conversion is out of scope
     * for a codec library.  However, the TurboJPEG API allows for compressing
     * CMYK pixels into a YCCK JPEG image (see #TJCS_YCCK) and decompressing YCCK
     * JPEG images into CMYK pixels.
     */
    TJPF_CMYK
  };
  
  
  /**
   * Red offset (in bytes) for a given pixel format.  This specifies the number
   * of bytes that the red component is offset from the start of the pixel.  For
   * instance, if a pixel of format TJ_BGRX is stored in <tt>char pixel[]</tt>,
   * then the red component will be <tt>pixel[tjRedOffset[TJ_BGRX]]</tt>.
   */
  static const int tjRedOffset[TJ_NUMPF] = {0, 2, 0, 2, 3, 1, 0, 0, 2, 3, 1, -1};
  /**
   * Green offset (in bytes) for a given pixel format.  This specifies the number
   * of bytes that the green component is offset from the start of the pixel.
   * For instance, if a pixel of format TJ_BGRX is stored in
   * <tt>char pixel[]</tt>, then the green component will be
   * <tt>pixel[tjGreenOffset[TJ_BGRX]]</tt>.
   */
  static const int tjGreenOffset[TJ_NUMPF] = {1, 1, 1, 1, 2, 2, 0, 1, 1, 2, 2, -1};
  /**
   * Blue offset (in bytes) for a given pixel format.  This specifies the number
   * of bytes that the Blue component is offset from the start of the pixel.  For
   * instance, if a pixel of format TJ_BGRX is stored in <tt>char pixel[]</tt>,
   * then the blue component will be <tt>pixel[tjBlueOffset[TJ_BGRX]]</tt>.
   */
  static const int tjBlueOffset[TJ_NUMPF] = {2, 0, 2, 0, 1, 3, 0, 2, 0, 1, 3, -1};
  
  /**
   * Pixel size (in bytes) for a given pixel format.
   */
  static const int tjPixelSize[TJ_NUMPF] = {3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 4, 4};
  
  
  /**
   * The number of JPEG colorspaces
   */
  #define TJ_NUMCS 5
  
  /**
   * JPEG colorspaces
   */
  enum TJCS
  {
    /**
     * RGB colorspace.  When compressing the JPEG image, the R, G, and B
     * components in the source image are reordered into image planes, but no
     * colorspace conversion or subsampling is performed.  RGB JPEG images can be
     * decompressed to any of the extended RGB pixel formats or grayscale, but
     * they cannot be decompressed to YUV images.
     */
    TJCS_RGB=0,
    /**
     * YCbCr colorspace.  YCbCr is not an absolute colorspace but rather a
     * mathematical transformation of RGB designed solely for storage and
     * transmission.  YCbCr images must be converted to RGB before they can
     * actually be displayed.  In the YCbCr colorspace, the Y (luminance)
     * component represents the black & white portion of the original image, and
     * the Cb and Cr (chrominance) components represent the color portion of the
     * original image.  Originally, the analog equivalent of this transformation
     * allowed the same signal to drive both black & white and color televisions,
     * but JPEG images use YCbCr primarily because it allows the color data to be
     * optionally subsampled for the purposes of reducing bandwidth or disk
     * space.  YCbCr is the most common JPEG colorspace, and YCbCr JPEG images
     * can be compressed from and decompressed to any of the extended RGB pixel
     * formats or grayscale, or they can be decompressed to YUV planar images.
     */
    TJCS_YCbCr,
    /**
     * Grayscale colorspace.  The JPEG image retains only the luminance data (Y
     * component), and any color data from the source image is discarded.
     * Grayscale JPEG images can be compressed from and decompressed to any of
     * the extended RGB pixel formats or grayscale, or they can be decompressed
     * to YUV planar images.
     */
    TJCS_GRAY,
    /**
     * CMYK colorspace.  When compressing the JPEG image, the C, M, Y, and K
     * components in the source image are reordered into image planes, but no
     * colorspace conversion or subsampling is performed.  CMYK JPEG images can
     * only be decompressed to CMYK pixels.
     */
    TJCS_CMYK,
    /**
     * YCCK colorspace.  YCCK (AKA "YCbCrK") is not an absolute colorspace but
     * rather a mathematical transformation of CMYK designed solely for storage
     * and transmission.  It is to CMYK as YCbCr is to RGB.  CMYK pixels can be
     * reversibly transformed into YCCK, and as with YCbCr, the chrominance
     * components in the YCCK pixels can be subsampled without incurring major
     * perceptual loss.  YCCK JPEG images can only be compressed from and
     * decompressed to CMYK pixels.
     */
    TJCS_YCCK
  };
  
  
  /**
   * The uncompressed source/destination image is stored in bottom-up (Windows,
   * OpenGL) order, not top-down (X11) order.
   */
  #define TJFLAG_BOTTOMUP        2
  /**
   * When decompressing an image that was compressed using chrominance
   * subsampling, use the fastest chrominance upsampling algorithm available in
   * the underlying codec.  The default is to use smooth upsampling, which
   * creates a smooth transition between neighboring chrominance components in
   * order to reduce upsampling artifacts in the decompressed image.
   */
  #define TJFLAG_FASTUPSAMPLE  256
  /**
   * Disable buffer (re)allocation.  If passed to #tjCompress2() or
   * #tjTransform(), this flag will cause those functions to generate an error if
   * the JPEG image buffer is invalid or too small rather than attempting to
   * allocate or reallocate that buffer.  This reproduces the behavior of earlier
   * versions of TurboJPEG.
   */
  #define TJFLAG_NOREALLOC     1024
  /**
   * Use the fastest DCT/IDCT algorithm available in the underlying codec.  The
   * default if this flag is not specified is implementation-specific.  For
   * example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast
   * algorithm by default when compressing, because this has been shown to have
   * only a very slight effect on accuracy, but it uses the accurate algorithm
   * when decompressing, because this has been shown to have a larger effect.
   */
  #define TJFLAG_FASTDCT       2048
  /**
   * Use the most accurate DCT/IDCT algorithm available in the underlying codec.
   * The default if this flag is not specified is implementation-specific.  For
   * example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast
   * algorithm by default when compressing, because this has been shown to have
   * only a very slight effect on accuracy, but it uses the accurate algorithm
   * when decompressing, because this has been shown to have a larger effect.
   */
  #define TJFLAG_ACCURATEDCT   4096
  
  
  /**
   * The number of transform operations
   */
  #define TJ_NUMXOP 8
  
  /**
   * Transform operations for #tjTransform()
   */
  enum TJXOP
  {
    /**
     * Do not transform the position of the image pixels
     */
    TJXOP_NONE=0,
    /**
     * Flip (mirror) image horizontally.  This transform is imperfect if there
     * are any partial MCU blocks on the right edge (see #TJXOPT_PERFECT.)
     */
    TJXOP_HFLIP,
    /**
     * Flip (mirror) image vertically.  This transform is imperfect if there are
     * any partial MCU blocks on the bottom edge (see #TJXOPT_PERFECT.)
     */
    TJXOP_VFLIP,
    /**
     * Transpose image (flip/mirror along upper left to lower right axis.)  This
     * transform is always perfect.
     */
    TJXOP_TRANSPOSE,
    /**
     * Transverse transpose image (flip/mirror along upper right to lower left
     * axis.)  This transform is imperfect if there are any partial MCU blocks in
     * the image (see #TJXOPT_PERFECT.)
     */
    TJXOP_TRANSVERSE,
    /**
     * Rotate image clockwise by 90 degrees.  This transform is imperfect if
     * there are any partial MCU blocks on the bottom edge (see
     * #TJXOPT_PERFECT.)
     */
    TJXOP_ROT90,
    /**
     * Rotate image 180 degrees.  This transform is imperfect if there are any
     * partial MCU blocks in the image (see #TJXOPT_PERFECT.)
     */
    TJXOP_ROT180,
    /**
     * Rotate image counter-clockwise by 90 degrees.  This transform is imperfect
     * if there are any partial MCU blocks on the right edge (see
     * #TJXOPT_PERFECT.)
     */
    TJXOP_ROT270
  };
  
  
  /**
   * This option will cause #tjTransform() to return an error if the transform is
   * not perfect.  Lossless transforms operate on MCU blocks, whose size depends
   * on the level of chrominance subsampling used (see #tjMCUWidth
   * and #tjMCUHeight.)  If the image's width or height is not evenly divisible
   * by the MCU block size, then there will be partial MCU blocks on the right
   * and/or bottom edges.  It is not possible to move these partial MCU blocks to
   * the top or left of the image, so any transform that would require that is
   * "imperfect."  If this option is not specified, then any partial MCU blocks
   * that cannot be transformed will be left in place, which will create
   * odd-looking strips on the right or bottom edge of the image.
   */
  #define TJXOPT_PERFECT  1
  /**
   * This option will cause #tjTransform() to discard any partial MCU blocks that
   * cannot be transformed.
   */
  #define TJXOPT_TRIM     2
  /**
   * This option will enable lossless cropping.  See #tjTransform() for more
   * information.
   */
  #define TJXOPT_CROP     4
  /**
   * This option will discard the color data in the input image and produce
   * a grayscale output image.
   */
  #define TJXOPT_GRAY     8
  /**
   * This option will prevent #tjTransform() from outputting a JPEG image for
   * this particular transform (this can be used in conjunction with a custom
   * filter to capture the transformed DCT coefficients without transcoding
   * them.)
   */
  #define TJXOPT_NOOUTPUT 16
  
  
  /**
   * Scaling factor
   */
  typedef struct
  {
    /**
     * Numerator
     */
    int num;
    /**
     * Denominator
     */
    int denom;
  } tjscalingfactor;
  
  /**
   * Cropping region
   */
  typedef struct
  {
    /**
     * The left boundary of the cropping region.  This must be evenly divisible
     * by the MCU block width (see #tjMCUWidth.)
     */
    int x;
    /**
     * The upper boundary of the cropping region.  This must be evenly divisible
     * by the MCU block height (see #tjMCUHeight.)
     */
    int y;
    /**
     * The width of the cropping region. Setting this to 0 is the equivalent of
     * setting it to the width of the source JPEG image - x.
     */
    int w;
    /**
     * The height of the cropping region. Setting this to 0 is the equivalent of
     * setting it to the height of the source JPEG image - y.
     */
    int h;
  } tjregion;
  
  /**
   * Lossless transform
   */
  typedef struct tjtransform
  {
    /**
     * Cropping region
     */
    tjregion r;
    /**
     * One of the @ref TJXOP "transform operations"
     */
    int op;
    /**
     * The bitwise OR of one of more of the @ref TJXOPT_CROP "transform options"
     */
    int options;
    /**
     * Arbitrary data that can be accessed within the body of the callback
     * function
     */
    void *data;
    /**
     * A callback function that can be used to modify the DCT coefficients
     * after they are losslessly transformed but before they are transcoded to a
     * new JPEG image.  This allows for custom filters or other transformations
     * to be applied in the frequency domain.
     *
     * @param coeffs pointer to an array of transformed DCT coefficients.  (NOTE:
     * this pointer is not guaranteed to be valid once the callback returns, so
     * applications wishing to hand off the DCT coefficients to another function
     * or library should make a copy of them within the body of the callback.)
     *
     * @param arrayRegion #tjregion structure containing the width and height of
     * the array pointed to by <tt>coeffs</tt> as well as its offset relative to
     * the component plane.  TurboJPEG implementations may choose to split each
     * component plane into multiple DCT coefficient arrays and call the callback
     * function once for each array.
     *
     * @param planeRegion #tjregion structure containing the width and height of
     * the component plane to which <tt>coeffs</tt> belongs
     *
     * @param componentID ID number of the component plane to which
     * <tt>coeffs</tt> belongs (Y, Cb, and Cr have, respectively, ID's of 0, 1,
     * and 2 in typical JPEG images.)
     *
     * @param transformID ID number of the transformed image to which
     * <tt>coeffs</tt> belongs.  This is the same as the index of the transform
     * in the <tt>transforms</tt> array that was passed to #tjTransform().
     *
     * @param transform a pointer to a #tjtransform structure that specifies the
     * parameters and/or cropping region for this transform
     *
     * @return 0 if the callback was successful, or -1 if an error occurred.
     */
    int (*customFilter)(short *coeffs, tjregion arrayRegion,
      tjregion planeRegion, int componentIndex, int transformIndex,
      struct tjtransform *transform);
  } tjtransform;
  
  /**
   * TurboJPEG instance handle
   */
  typedef void* tjhandle;
  
  
  /**
   * Pad the given width to the nearest 32-bit boundary
   */
  #define TJPAD(width) (((width)+3)&(~3))
  
  /**
   * Compute the scaled value of <tt>dimension</tt> using the given scaling
   * factor.  This macro performs the integer equivalent of <tt>ceil(dimension *
   * scalingFactor)</tt>.
   */
  #define TJSCALED(dimension, scalingFactor) ((dimension * scalingFactor.num \
    + scalingFactor.denom - 1) / scalingFactor.denom)
  
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  
  /**
   * Create a TurboJPEG compressor instance.
   *
   * @return a handle to the newly-created instance, or NULL if an error
   * occurred (see #tjGetErrorStr().)
   */
  DLLEXPORT tjhandle DLLCALL tjInitCompress(void);
  
  
  /**
   * Compress an RGB, grayscale, or CMYK image into a JPEG image.
   *
   * @param handle a handle to a TurboJPEG compressor or transformer instance
   *
   * @param srcBuf pointer to an image buffer containing RGB, grayscale, or
   * CMYK pixels to be compressed
   *
   * @param width width (in pixels) of the source image
   *
   * @param pitch bytes per line in the source image.  Normally, this should be
   * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or
   * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image
   * is padded to the nearest 32-bit boundary, as is the case for Windows
   * bitmaps.  You can also be clever and use this parameter to skip lines, etc.
   * Setting this parameter to 0 is the equivalent of setting it to
   * <tt>width * #tjPixelSize[pixelFormat]</tt>.
   *
   * @param height height (in pixels) of the source image
   *
   * @param pixelFormat pixel format of the source image (see @ref TJPF
   * "Pixel formats".)
   *
   * @param jpegBuf address of a pointer to an image buffer that will receive the
   * JPEG image.  TurboJPEG has the ability to reallocate the JPEG buffer
   * to accommodate the size of the JPEG image.  Thus, you can choose to:
   * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
   * let TurboJPEG grow the buffer as needed,
   * -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer
   * for you, or
   * -# pre-allocate the buffer to a "worst case" size determined by calling
   * #tjBufSize().  This should ensure that the buffer never has to be
   * re-allocated (setting #TJFLAG_NOREALLOC guarantees this.)
   * .
   * If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your
   * pre-allocated buffer.  In any case, unless you have set #TJFLAG_NOREALLOC,
   * you should always check <tt>*jpegBuf</tt> upon return from this function, as
   * it may have changed.
   *
   * @param jpegSize pointer to an unsigned long variable that holds the size of
   * the JPEG image buffer.  If <tt>*jpegBuf</tt> points to a pre-allocated
   * buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer.
   * Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in
   * bytes.)  If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being
   * reused from a previous call to one of the JPEG compression functions, then
   * <tt>*jpegSize</tt> is ignored.
   *
   * @param jpegSubsamp the level of chrominance subsampling to be used when
   * generating the JPEG image (see @ref TJSAMP
   * "Chrominance subsampling options".)
   *
   * @param jpegQual the image quality of the generated JPEG image (1 = worst,
   * 100 = best)
   *
   * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
   * "flags"
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
  */
  DLLEXPORT int DLLCALL tjCompress2(tjhandle handle, const unsigned char *srcBuf,
    int width, int pitch, int height, int pixelFormat, unsigned char **jpegBuf,
    unsigned long *jpegSize, int jpegSubsamp, int jpegQual, int flags);
  
  
  /**
   * Compress a YUV planar image into a JPEG image.
   *
   * @param handle a handle to a TurboJPEG compressor or transformer instance
   *
   * @param srcBuf pointer to an image buffer containing a YUV planar image to be
   * compressed.  The size of this buffer should match the value returned by
   * #tjBufSizeYUV2() for the given image width, height, padding, and level of
   * chrominance subsampling.  The Y, U (Cb), and V (Cr) image planes should be
   * stored sequentially in the source buffer (refer to @ref YUVnotes
   * "YUV Image Format Notes".)
   *
   * @param width width (in pixels) of the source image.  If the width is not an
   * even multiple of the MCU block width (see #tjMCUWidth), then an intermediate
   * buffer copy will be performed within TurboJPEG.
   *
   * @param pad the line padding used in the source image.  For instance, if each
   * line in each plane of the YUV image is padded to the nearest multiple of 4
   * bytes, then <tt>pad</tt> should be set to 4.
   *
   * @param height height (in pixels) of the source image.  If the height is not
   * an even multiple of the MCU block height (see #tjMCUHeight), then an
   * intermediate buffer copy will be performed within TurboJPEG.
   *
   * @param subsamp the level of chrominance subsampling used in the source
   * image (see @ref TJSAMP "Chrominance subsampling options".)
   *
   * @param jpegBuf address of a pointer to an image buffer that will receive the
   * JPEG image.  TurboJPEG has the ability to reallocate the JPEG buffer to
   * accommodate the size of the JPEG image.  Thus, you can choose to:
   * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
   * let TurboJPEG grow the buffer as needed,
   * -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer
   * for you, or
   * -# pre-allocate the buffer to a "worst case" size determined by calling
   * #tjBufSize().  This should ensure that the buffer never has to be
   * re-allocated (setting #TJFLAG_NOREALLOC guarantees this.)
   * .
   * If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your
   * pre-allocated buffer.  In any case, unless you have set #TJFLAG_NOREALLOC,
   * you should always check <tt>*jpegBuf</tt> upon return from this function, as
   * it may have changed.
   *
   * @param jpegSize pointer to an unsigned long variable that holds the size of
   * the JPEG image buffer.  If <tt>*jpegBuf</tt> points to a pre-allocated
   * buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer.
   * Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in
   * bytes.)  If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being
   * reused from a previous call to one of the JPEG compression functions, then
   * <tt>*jpegSize</tt> is ignored.
   *
   * @param jpegQual the image quality of the generated JPEG image (1 = worst,
   * 100 = best)
   *
   * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
   * "flags"
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
  */
  DLLEXPORT int DLLCALL tjCompressFromYUV(tjhandle handle,
    const unsigned char *srcBuf, int width, int pad, int height, int subsamp,
    unsigned char **jpegBuf, unsigned long *jpegSize, int jpegQual, int flags);
  
  
  /**
   * Compress a set of Y, U (Cb), and V (Cr) image planes into a JPEG image.
   *
   * @param handle a handle to a TurboJPEG compressor or transformer instance
   *
   * @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
   * (or just a Y plane, if compressing a grayscale image) that contain a YUV
   * image to be compressed.  These planes can be contiguous or non-contiguous in
   * memory.  The size of each plane should match the value returned by
   * #tjPlaneSizeYUV() for the given image width, height, strides, and level of
   * chrominance subsampling.  Refer to @ref YUVnotes "YUV Image Format Notes"
   * for more details.
   *
   * @param width width (in pixels) of the source image.  If the width is not an
   * even multiple of the MCU block width (see #tjMCUWidth), then an intermediate
   * buffer copy will be performed within TurboJPEG.
   *
   * @param strides an array of integers, each specifying the number of bytes per
   * line in the corresponding plane of the YUV source image.  Setting the stride
   * for any plane to 0 is the same as setting it to the plane width (see
   * @ref YUVnotes "YUV Image Format Notes".)  If <tt>strides</tt> is NULL, then
   * the strides for all planes will be set to their respective plane widths.
   * You can adjust the strides in order to specify an arbitrary amount of line
   * padding in each plane or to create a JPEG image from a subregion of a larger
   * YUV planar image.
   *
   * @param height height (in pixels) of the source image.  If the height is not
   * an even multiple of the MCU block height (see #tjMCUHeight), then an
   * intermediate buffer copy will be performed within TurboJPEG.
   *
   * @param subsamp the level of chrominance subsampling used in the source
   * image (see @ref TJSAMP "Chrominance subsampling options".)
   *
   * @param jpegBuf address of a pointer to an image buffer that will receive the
   * JPEG image.  TurboJPEG has the ability to reallocate the JPEG buffer to
   * accommodate the size of the JPEG image.  Thus, you can choose to:
   * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
   * let TurboJPEG grow the buffer as needed,
   * -# set <tt>*jpegBuf</tt> to NULL to tell TurboJPEG to allocate the buffer
   * for you, or
   * -# pre-allocate the buffer to a "worst case" size determined by calling
   * #tjBufSize().  This should ensure that the buffer never has to be
   * re-allocated (setting #TJFLAG_NOREALLOC guarantees this.)
   * .
   * If you choose option 1, <tt>*jpegSize</tt> should be set to the size of your
   * pre-allocated buffer.  In any case, unless you have set #TJFLAG_NOREALLOC,
   * you should always check <tt>*jpegBuf</tt> upon return from this function, as
   * it may have changed.
   *
   * @param jpegSize pointer to an unsigned long variable that holds the size of
   * the JPEG image buffer.  If <tt>*jpegBuf</tt> points to a pre-allocated
   * buffer, then <tt>*jpegSize</tt> should be set to the size of the buffer.
   * Upon return, <tt>*jpegSize</tt> will contain the size of the JPEG image (in
   * bytes.)  If <tt>*jpegBuf</tt> points to a JPEG image buffer that is being
   * reused from a previous call to one of the JPEG compression functions, then
   * <tt>*jpegSize</tt> is ignored.
   *
   * @param jpegQual the image quality of the generated JPEG image (1 = worst,
   * 100 = best)
   *
   * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
   * "flags"
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
  */
  DLLEXPORT int DLLCALL tjCompressFromYUVPlanes(tjhandle handle,
    const unsigned char **srcPlanes, int width, const int *strides, int height,
    int subsamp, unsigned char **jpegBuf, unsigned long *jpegSize, int jpegQual,
    int flags);
  
  
  /**
   * The maximum size of the buffer (in bytes) required to hold a JPEG image with
   * the given parameters.  The number of bytes returned by this function is
   * larger than the size of the uncompressed source image.  The reason for this
   * is that the JPEG format uses 16-bit coefficients, and it is thus possible
   * for a very high-quality JPEG image with very high-frequency content to
   * expand rather than compress when converted to the JPEG format.  Such images
   * represent a very rare corner case, but since there is no way to predict the
   * size of a JPEG image prior to compression, the corner case has to be
   * handled.
   *
   * @param width width (in pixels) of the image
   *
   * @param height height (in pixels) of the image
   *
   * @param jpegSubsamp the level of chrominance subsampling to be used when
   * generating the JPEG image (see @ref TJSAMP
   * "Chrominance subsampling options".)
   *
   * @return the maximum size of the buffer (in bytes) required to hold the
   * image, or -1 if the arguments are out of bounds.
   */
  DLLEXPORT unsigned long DLLCALL tjBufSize(int width, int height,
    int jpegSubsamp);
  
  
  /**
   * The size of the buffer (in bytes) required to hold a YUV planar image with
   * the given parameters.
   *
   * @param width width (in pixels) of the image
   *
   * @param pad the width of each line in each plane of the image is padded to
   * the nearest multiple of this number of bytes (must be a power of 2.)
   *
   * @param height height (in pixels) of the image
   *
   * @param subsamp level of chrominance subsampling in the image (see
   * @ref TJSAMP "Chrominance subsampling options".)
   *
   * @return the size of the buffer (in bytes) required to hold the image, or
   * -1 if the arguments are out of bounds.
   */
  DLLEXPORT unsigned long DLLCALL tjBufSizeYUV2(int width, int pad, int height,
    int subsamp);
  
  
  /**
   * The size of the buffer (in bytes) required to hold a YUV image plane with
   * the given parameters.
   *
   * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
   *
   * @param width width (in pixels) of the YUV image.  NOTE: this is the width of
   * the whole image, not the plane width.
   *
   * @param stride bytes per line in the image plane.  Setting this to 0 is the
   * equivalent of setting it to the plane width.
   *
   * @param height height (in pixels) of the YUV image.  NOTE: this is the height
   * of the whole image, not the plane height.
   *
   * @param subsamp level of chrominance subsampling in the image (see
   * @ref TJSAMP "Chrominance subsampling options".)
   *
   * @return the size of the buffer (in bytes) required to hold the YUV image
   * plane, or -1 if the arguments are out of bounds.
   */
  DLLEXPORT unsigned long DLLCALL tjPlaneSizeYUV(int componentID, int width,
    int stride, int height, int subsamp);
  
  
  /**
   * The plane width of a YUV image plane with the given parameters.  Refer to
   * @ref YUVnotes "YUV Image Format Notes" for a description of plane width.
   *
   * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
   *
   * @param width width (in pixels) of the YUV image
   *
   * @param subsamp level of chrominance subsampling in the image (see
   * @ref TJSAMP "Chrominance subsampling options".)
   *
   * @return the plane width of a YUV image plane with the given parameters, or
   * -1 if the arguments are out of bounds.
   */
  DLLEXPORT int tjPlaneWidth(int componentID, int width, int subsamp);
  
  
  /**
   * The plane height of a YUV image plane with the given parameters.  Refer to
   * @ref YUVnotes "YUV Image Format Notes" for a description of plane height.
   *
   * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
   *
   * @param height height (in pixels) of the YUV image
   *
   * @param subsamp level of chrominance subsampling in the image (see
   * @ref TJSAMP "Chrominance subsampling options".)
   *
   * @return the plane height of a YUV image plane with the given parameters, or
   * -1 if the arguments are out of bounds.
   */
  DLLEXPORT int tjPlaneHeight(int componentID, int height, int subsamp);
  
  
  /**
   * Encode an RGB or grayscale image into a YUV planar image.  This function
   * uses the accelerated color conversion routines in the underlying
   * codec but does not execute any of the other steps in the JPEG compression
   * process.
   *
   * @param handle a handle to a TurboJPEG compressor or transformer instance
   *
   * @param srcBuf pointer to an image buffer containing RGB or grayscale pixels
   * to be encoded
   *
   * @param width width (in pixels) of the source image
   *
   * @param pitch bytes per line in the source image.  Normally, this should be
   * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or
   * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image
   * is padded to the nearest 32-bit boundary, as is the case for Windows
   * bitmaps.  You can also be clever and use this parameter to skip lines, etc.
   * Setting this parameter to 0 is the equivalent of setting it to
   * <tt>width * #tjPixelSize[pixelFormat]</tt>.
   *
   * @param height height (in pixels) of the source image
   *
   * @param pixelFormat pixel format of the source image (see @ref TJPF
   * "Pixel formats".)
   *
   * @param dstBuf pointer to an image buffer that will receive the YUV image.
   * Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based
   * on the image width, height, padding, and level of chrominance subsampling.
   * The Y, U (Cb), and V (Cr) image planes will be stored sequentially in the
   * buffer (refer to @ref YUVnotes "YUV Image Format Notes".)
   *
   * @param pad the width of each line in each plane of the YUV image will be
   * padded to the nearest multiple of this number of bytes (must be a power of
   * 2.)  To generate images suitable for X Video, <tt>pad</tt> should be set to
   * 4.
   *
   * @param subsamp the level of chrominance subsampling to be used when
   * generating the YUV image (see @ref TJSAMP
   * "Chrominance subsampling options".)  To generate images suitable for X
   * Video, <tt>subsamp</tt> should be set to @ref TJSAMP_420.  This produces an
   * image compatible with the I420 (AKA "YUV420P") format.
   *
   * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
   * "flags"
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
  */
  DLLEXPORT int DLLCALL tjEncodeYUV3(tjhandle handle,
    const unsigned char *srcBuf, int width, int pitch, int height,
    int pixelFormat, unsigned char *dstBuf, int pad, int subsamp, int flags);
  
  
  /**
   * Encode an RGB or grayscale image into separate Y, U (Cb), and V (Cr) image
   * planes.  This function uses the accelerated color conversion routines in the
   * underlying codec but does not execute any of the other steps in the JPEG
   * compression process.
   *
   * @param handle a handle to a TurboJPEG compressor or transformer instance
   *
   * @param srcBuf pointer to an image buffer containing RGB or grayscale pixels
   * to be encoded
   *
   * @param width width (in pixels) of the source image
   *
   * @param pitch bytes per line in the source image.  Normally, this should be
   * <tt>width * #tjPixelSize[pixelFormat]</tt> if the image is unpadded, or
   * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line of the image
   * is padded to the nearest 32-bit boundary, as is the case for Windows
   * bitmaps.  You can also be clever and use this parameter to skip lines, etc.
   * Setting this parameter to 0 is the equivalent of setting it to
   * <tt>width * #tjPixelSize[pixelFormat]</tt>.
   *
   * @param height height (in pixels) of the source image
   *
   * @param pixelFormat pixel format of the source image (see @ref TJPF
   * "Pixel formats".)
   *
   * @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
   * (or just a Y plane, if generating a grayscale image) that will receive the
   * encoded image.  These planes can be contiguous or non-contiguous in memory.
   * Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based
   * on the image width, height, strides, and level of chrominance subsampling.
   * Refer to @ref YUVnotes "YUV Image Format Notes" for more details.
   *
   * @param strides an array of integers, each specifying the number of bytes per
   * line in the corresponding plane of the output image.  Setting the stride for
   * any plane to 0 is the same as setting it to the plane width (see
   * @ref YUVnotes "YUV Image Format Notes".)  If <tt>strides</tt> is NULL, then
   * the strides for all planes will be set to their respective plane widths.
   * You can adjust the strides in order to add an arbitrary amount of line
   * padding to each plane or to encode an RGB or grayscale image into a
   * subregion of a larger YUV planar image.
   *
   * @param subsamp the level of chrominance subsampling to be used when
   * generating the YUV image (see @ref TJSAMP
   * "Chrominance subsampling options".)  To generate images suitable for X
   * Video, <tt>subsamp</tt> should be set to @ref TJSAMP_420.  This produces an
   * image compatible with the I420 (AKA "YUV420P") format.
   *
   * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
   * "flags"
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
  */
  DLLEXPORT int DLLCALL tjEncodeYUVPlanes(tjhandle handle,
    const unsigned char *srcBuf, int width, int pitch, int height,
    int pixelFormat, unsigned char **dstPlanes, int *strides, int subsamp,
    int flags);
  
  
  /**
   * Create a TurboJPEG decompressor instance.
   *
   * @return a handle to the newly-created instance, or NULL if an error
   * occurred (see #tjGetErrorStr().)
  */
  DLLEXPORT tjhandle DLLCALL tjInitDecompress(void);
  
  
  /**
   * Retrieve information about a JPEG image without decompressing it.
   *
   * @param handle a handle to a TurboJPEG decompressor or transformer instance
   *
   * @param jpegBuf pointer to a buffer containing a JPEG image
   *
   * @param jpegSize size of the JPEG image (in bytes)
   *
   * @param width pointer to an integer variable that will receive the width (in
   * pixels) of the JPEG image
   *
   * @param height pointer to an integer variable that will receive the height
   * (in pixels) of the JPEG image
   *
   * @param jpegSubsamp pointer to an integer variable that will receive the
   * level of chrominance subsampling used when the JPEG image was compressed
   * (see @ref TJSAMP "Chrominance subsampling options".)
   *
   * @param jpegColorspace pointer to an integer variable that will receive one
   * of the JPEG colorspace constants, indicating the colorspace of the JPEG
   * image (see @ref TJCS "JPEG colorspaces".)
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
  */
  DLLEXPORT int DLLCALL tjDecompressHeader3(tjhandle handle,
    const unsigned char *jpegBuf, unsigned long jpegSize, int *width,
    int *height, int *jpegSubsamp, int *jpegColorspace);
  
  
  /**
   * Returns a list of fractional scaling factors that the JPEG decompressor in
   * this implementation of TurboJPEG supports.
   *
   * @param numscalingfactors pointer to an integer variable that will receive
   * the number of elements in the list
   *
   * @return a pointer to a list of fractional scaling factors, or NULL if an
   * error is encountered (see #tjGetErrorStr().)
  */
  DLLEXPORT tjscalingfactor* DLLCALL tjGetScalingFactors(int *numscalingfactors);
  
  
  /**
   * Decompress a JPEG image to an RGB, grayscale, or CMYK image.
   *
   * @param handle a handle to a TurboJPEG decompressor or transformer instance
   *
   * @param jpegBuf pointer to a buffer containing the JPEG image to decompress
   *
   * @param jpegSize size of the JPEG image (in bytes)
   *
   * @param dstBuf pointer to an image buffer that will receive the decompressed
   * image.  This buffer should normally be <tt>pitch * scaledHeight</tt> bytes
   * in size, where <tt>scaledHeight</tt> can be determined by calling
   * #TJSCALED() with the JPEG image height and one of the scaling factors
   * returned by #tjGetScalingFactors().  The <tt>dstBuf</tt> pointer may also be
   * used to decompress into a specific region of a larger buffer.
   *
   * @param width desired width (in pixels) of the destination image.  If this is
   * different than the width of the JPEG image being decompressed, then
   * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
   * possible image that will fit within the desired width.  If <tt>width</tt> is
   * set to 0, then only the height will be considered when determining the
   * scaled image size.
   *
   * @param pitch bytes per line in the destination image.  Normally, this is
   * <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt> if the decompressed image
   * is unpadded, else <tt>#TJPAD(scaledWidth * #tjPixelSize[pixelFormat])</tt>
   * if each line of the decompressed image is padded to the nearest 32-bit
   * boundary, as is the case for Windows bitmaps.  (NOTE: <tt>scaledWidth</tt>
   * can be determined by calling #TJSCALED() with the JPEG image width and one
   * of the scaling factors returned by #tjGetScalingFactors().)  You can also be
   * clever and use the pitch parameter to skip lines, etc.  Setting this
   * parameter to 0 is the equivalent of setting it to
   * <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt>.
   *
   * @param height desired height (in pixels) of the destination image.  If this
   * is different than the height of the JPEG image being decompressed, then
   * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
   * possible image that will fit within the desired height.  If <tt>height</tt>
   * is set to 0, then only the width will be considered when determining the
   * scaled image size.
   *
   * @param pixelFormat pixel format of the destination image (see @ref
   * TJPF "Pixel formats".)
   *
   * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
   * "flags"
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
   */
  DLLEXPORT int DLLCALL tjDecompress2(tjhandle handle,
    const unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf,
    int width, int pitch, int height, int pixelFormat, int flags);
  
  
  /**
   * Decompress a JPEG image to a YUV planar image.  This function performs JPEG
   * decompression but leaves out the color conversion step, so a planar YUV
   * image is generated instead of an RGB image.
   *
   * @param handle a handle to a TurboJPEG decompressor or transformer instance
   *
   * @param jpegBuf pointer to a buffer containing the JPEG image to decompress
   *
   * @param jpegSize size of the JPEG image (in bytes)
   *
   * @param dstBuf pointer to an image buffer that will receive the YUV image.
   * Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based
   * on the image width, height, padding, and level of subsampling.  The Y,
   * U (Cb), and V (Cr) image planes will be stored sequentially in the buffer
   * (refer to @ref YUVnotes "YUV Image Format Notes".)
   *
   * @param width desired width (in pixels) of the YUV image.  If this is
   * different than the width of the JPEG image being decompressed, then
   * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
   * possible image that will fit within the desired width.  If <tt>width</tt> is
   * set to 0, then only the height will be considered when determining the
   * scaled image size.  If the scaled width is not an even multiple of the MCU
   * block width (see #tjMCUWidth), then an intermediate buffer copy will be
   * performed within TurboJPEG.
   *
   * @param pad the width of each line in each plane of the YUV image will be
   * padded to the nearest multiple of this number of bytes (must be a power of
   * 2.)  To generate images suitable for X Video, <tt>pad</tt> should be set to
   * 4.
   *
   * @param height desired height (in pixels) of the YUV image.  If this is
   * different than the height of the JPEG image being decompressed, then
   * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
   * possible image that will fit within the desired height.  If <tt>height</tt>
   * is set to 0, then only the width will be considered when determining the
   * scaled image size.  If the scaled height is not an even multiple of the MCU
   * block height (see #tjMCUHeight), then an intermediate buffer copy will be
   * performed within TurboJPEG.
   *
   * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
   * "flags"
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
   */
  DLLEXPORT int DLLCALL tjDecompressToYUV2(tjhandle handle,
    const unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf,
    int width, int pad, int height, int flags);
  
  
  /**
   * Decompress a JPEG image into separate Y, U (Cb), and V (Cr) image
   * planes.  This function performs JPEG decompression but leaves out the color
   * conversion step, so a planar YUV image is generated instead of an RGB image.
   *
   * @param handle a handle to a TurboJPEG decompressor or transformer instance
   *
   * @param jpegBuf pointer to a buffer containing the JPEG image to decompress
   *
   * @param jpegSize size of the JPEG image (in bytes)
   *
   * @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
   * (or just a Y plane, if decompressing a grayscale image) that will receive
   * the YUV image.  These planes can be contiguous or non-contiguous in memory.
   * Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based
   * on the scaled image width, scaled image height, strides, and level of
   * chrominance subsampling.  Refer to @ref YUVnotes "YUV Image Format Notes"
   * for more details.
   *
   * @param width desired width (in pixels) of the YUV image.  If this is
   * different than the width of the JPEG image being decompressed, then
   * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
   * possible image that will fit within the desired width.  If <tt>width</tt> is
   * set to 0, then only the height will be considered when determining the
   * scaled image size.  If the scaled width is not an even multiple of the MCU
   * block width (see #tjMCUWidth), then an intermediate buffer copy will be
   * performed within TurboJPEG.
   *
   * @param strides an array of integers, each specifying the number of bytes per
   * line in the corresponding plane of the output image.  Setting the stride for
   * any plane to 0 is the same as setting it to the scaled plane width (see
   * @ref YUVnotes "YUV Image Format Notes".)  If <tt>strides</tt> is NULL, then
   * the strides for all planes will be set to their respective scaled plane
   * widths.  You can adjust the strides in order to add an arbitrary amount of
   * line padding to each plane or to decompress the JPEG image into a subregion
   * of a larger YUV planar image.
   *
   * @param height desired height (in pixels) of the YUV image.  If this is
   * different than the height of the JPEG image being decompressed, then
   * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
   * possible image that will fit within the desired height.  If <tt>height</tt>
   * is set to 0, then only the width will be considered when determining the
   * scaled image size.  If the scaled height is not an even multiple of the MCU
   * block height (see #tjMCUHeight), then an intermediate buffer copy will be
   * performed within TurboJPEG.
   *
   * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
   * "flags"
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
   */
  DLLEXPORT int DLLCALL tjDecompressToYUVPlanes(tjhandle handle,
    const unsigned char *jpegBuf, unsigned long jpegSize,
    unsigned char **dstPlanes, int width, int *strides, int height, int flags);
  
  
  /**
   * Decode a YUV planar image into an RGB or grayscale image.  This function
   * uses the accelerated color conversion routines in the underlying
   * codec but does not execute any of the other steps in the JPEG decompression
   * process.
   *
   * @param handle a handle to a TurboJPEG decompressor or transformer instance
   *
   * @param srcBuf pointer to an image buffer containing a YUV planar image to be
   * decoded.  The size of this buffer should match the value returned by
   * #tjBufSizeYUV2() for the given image width, height, padding, and level of
   * chrominance subsampling.  The Y, U (Cb), and V (Cr) image planes should be
   * stored sequentially in the source buffer (refer to @ref YUVnotes
   * "YUV Image Format Notes".)
   *
   * @param pad Use this parameter to specify that the width of each line in each
   * plane of the YUV source image is padded to the nearest multiple of this
   * number of bytes (must be a power of 2.)
   *
   * @param subsamp the level of chrominance subsampling used in the YUV source
   * image (see @ref TJSAMP "Chrominance subsampling options".)
   *
   * @param dstBuf pointer to an image buffer that will receive the decoded
   * image.  This buffer should normally be <tt>pitch * height</tt> bytes in
   * size, but the <tt>dstBuf</tt> pointer can also be used to decode into a
   * specific region of a larger buffer.
   *
   * @param width width (in pixels) of the source and destination images
   *
   * @param pitch bytes per line in the destination image.  Normally, this should
   * be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is
   * unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line
   * of the destination image should be padded to the nearest 32-bit boundary, as
   * is the case for Windows bitmaps.  You can also be clever and use the pitch
   * parameter to skip lines, etc.  Setting this parameter to 0 is the equivalent
   * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.
   *
   * @param height height (in pixels) of the source and destination images
   *
   * @param pixelFormat pixel format of the destination image (see @ref TJPF
   * "Pixel formats".)
   *
   * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
   * "flags"
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
   */
  DLLEXPORT int DLLCALL tjDecodeYUV(tjhandle handle, const unsigned char *srcBuf,
    int pad, int subsamp, unsigned char *dstBuf, int width, int pitch,
    int height, int pixelFormat, int flags);
  
  
  /**
   * Decode a set of Y, U (Cb), and V (Cr) image planes into an RGB or grayscale
   * image.  This function uses the accelerated color conversion routines in the
   * underlying codec but does not execute any of the other steps in the JPEG
   * decompression process.
   *
   * @param handle a handle to a TurboJPEG decompressor or transformer instance
   *
   * @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
   * (or just a Y plane, if decoding a grayscale image) that contain a YUV image
   * to be decoded.  These planes can be contiguous or non-contiguous in memory.
   * The size of each plane should match the value returned by #tjPlaneSizeYUV()
   * for the given image width, height, strides, and level of chrominance
   * subsampling.  Refer to @ref YUVnotes "YUV Image Format Notes" for more
   * details.
   *
   * @param strides an array of integers, each specifying the number of bytes per
   * line in the corresponding plane of the YUV source image.  Setting the stride
   * for any plane to 0 is the same as setting it to the plane width (see
   * @ref YUVnotes "YUV Image Format Notes".)  If <tt>strides</tt> is NULL, then
   * the strides for all planes will be set to their respective plane widths.
   * You can adjust the strides in order to specify an arbitrary amount of line
   * padding in each plane or to decode a subregion of a larger YUV planar image.
   *
   * @param subsamp the level of chrominance subsampling used in the YUV source
   * image (see @ref TJSAMP "Chrominance subsampling options".)
   *
   * @param dstBuf pointer to an image buffer that will receive the decoded
   * image.  This buffer should normally be <tt>pitch * height</tt> bytes in
   * size, but the <tt>dstBuf</tt> pointer can also be used to decode into a
   * specific region of a larger buffer.
   *
   * @param width width (in pixels) of the source and destination images
   *
   * @param pitch bytes per line in the destination image.  Normally, this should
   * be <tt>width * #tjPixelSize[pixelFormat]</tt> if the destination image is
   * unpadded, or <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each line
   * of the destination image should be padded to the nearest 32-bit boundary, as
   * is the case for Windows bitmaps.  You can also be clever and use the pitch
   * parameter to skip lines, etc.  Setting this parameter to 0 is the equivalent
   * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.
   *
   * @param height height (in pixels) of the source and destination images
   *
   * @param pixelFormat pixel format of the destination image (see @ref TJPF
   * "Pixel formats".)
   *
   * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
   * "flags"
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
   */
  DLLEXPORT int DLLCALL tjDecodeYUVPlanes(tjhandle handle,
    const unsigned char **srcPlanes, const int *strides, int subsamp,
    unsigned char *dstBuf, int width, int pitch, int height, int pixelFormat,
    int flags);
  
  
  /**
   * Create a new TurboJPEG transformer instance.
   *
   * @return a handle to the newly-created instance, or NULL if an error
   * occurred (see #tjGetErrorStr().)
   */
  DLLEXPORT tjhandle DLLCALL tjInitTransform(void);
  
  
  /**
   * Losslessly transform a JPEG image into another JPEG image.  Lossless
   * transforms work by moving the raw DCT coefficients from one JPEG image
   * structure to another without altering the values of the coefficients.  While
   * this is typically faster than decompressing the image, transforming it, and
   * re-compressing it, lossless transforms are not free.  Each lossless
   * transform requires reading and performing Huffman decoding on all of the
   * coefficients in the source image, regardless of the size of the destination
   * image.  Thus, this function provides a means of generating multiple
   * transformed images from the same source or  applying multiple
   * transformations simultaneously, in order to eliminate the need to read the
   * source coefficients multiple times.
   *
   * @param handle a handle to a TurboJPEG transformer instance
   *
   * @param jpegBuf pointer to a buffer containing the JPEG source image to
   * transform
   *
   * @param jpegSize size of the JPEG source image (in bytes)
   *
   * @param n the number of transformed JPEG images to generate
   *
   * @param dstBufs pointer to an array of n image buffers.  <tt>dstBufs[i]</tt>
   * will receive a JPEG image that has been transformed using the parameters in
   * <tt>transforms[i]</tt>.  TurboJPEG has the ability to reallocate the JPEG
   * buffer to accommodate the size of the JPEG image.  Thus, you can choose to:
   * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
   * let TurboJPEG grow the buffer as needed,
   * -# set <tt>dstBufs[i]</tt> to NULL to tell TurboJPEG to allocate the buffer
   * for you, or
   * -# pre-allocate the buffer to a "worst case" size determined by calling
   * #tjBufSize() with the transformed or cropped width and height.  This should
   * ensure that the buffer never has to be re-allocated (setting
   * #TJFLAG_NOREALLOC guarantees this.)
   * .
   * If you choose option 1, <tt>dstSizes[i]</tt> should be set to the size of
   * your pre-allocated buffer.  In any case, unless you have set
   * #TJFLAG_NOREALLOC, you should always check <tt>dstBufs[i]</tt> upon return
   * from this function, as it may have changed.
   *
   * @param dstSizes pointer to an array of n unsigned long variables that will
   * receive the actual sizes (in bytes) of each transformed JPEG image.  If
   * <tt>dstBufs[i]</tt> points to a pre-allocated buffer, then
   * <tt>dstSizes[i]</tt> should be set to the size of the buffer.  Upon return,
   * <tt>dstSizes[i]</tt> will contain the size of the JPEG image (in bytes.)
   *
   * @param transforms pointer to an array of n #tjtransform structures, each of
   * which specifies the transform parameters and/or cropping region for the
   * corresponding transformed output image.
   *
   * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
   * "flags"
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
   */
  DLLEXPORT int DLLCALL tjTransform(tjhandle handle,
    const unsigned char *jpegBuf, unsigned long jpegSize, int n,
    unsigned char **dstBufs, unsigned long *dstSizes, tjtransform *transforms,
    int flags);
  
  
  /**
   * Destroy a TurboJPEG compressor, decompressor, or transformer instance.
   *
   * @param handle a handle to a TurboJPEG compressor, decompressor or
   * transformer instance
   *
   * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr().)
   */
  DLLEXPORT int DLLCALL tjDestroy(tjhandle handle);
  
  
  /**
   * Allocate an image buffer for use with TurboJPEG.  You should always use
   * this function to allocate the JPEG destination buffer(s) for #tjCompress2()
   * and #tjTransform() unless you are disabling automatic buffer
   * (re)allocation (by setting #TJFLAG_NOREALLOC.)
   *
   * @param bytes the number of bytes to allocate
   *
   * @return a pointer to a newly-allocated buffer with the specified number of
   * bytes.
   *
   * @sa tjFree()
   */
  DLLEXPORT unsigned char* DLLCALL tjAlloc(int bytes);
  
  
  /**
   * Free an image buffer previously allocated by TurboJPEG.  You should always
   * use this function to free JPEG destination buffer(s) that were automatically
   * (re)allocated by #tjCompress2() or #tjTransform() or that were manually
   * allocated using #tjAlloc().
   *
   * @param buffer address of the buffer to free
   *
   * @sa tjAlloc()
   */
  DLLEXPORT void DLLCALL tjFree(unsigned char *buffer);
  
  
  /**
   * Returns a descriptive error message explaining why the last command failed.
   *
   * @return a descriptive error message explaining why the last command failed.
   */
  DLLEXPORT char* DLLCALL tjGetErrorStr(void);
  
  
  /* Deprecated functions and macros */
  #define TJFLAG_FORCEMMX        8
  #define TJFLAG_FORCESSE       16
  #define TJFLAG_FORCESSE2      32
  #define TJFLAG_FORCESSE3     128
  
  
  /* Backward compatibility functions and macros (nothing to see here) */
  #define NUMSUBOPT TJ_NUMSAMP
  #define TJ_444 TJSAMP_444
  #define TJ_422 TJSAMP_422
  #define TJ_420 TJSAMP_420
  #define TJ_411 TJSAMP_420
  #define TJ_GRAYSCALE TJSAMP_GRAY
  
  #define TJ_BGR 1
  #define TJ_BOTTOMUP TJFLAG_BOTTOMUP
  #define TJ_FORCEMMX TJFLAG_FORCEMMX
  #define TJ_FORCESSE TJFLAG_FORCESSE
  #define TJ_FORCESSE2 TJFLAG_FORCESSE2
  #define TJ_ALPHAFIRST 64
  #define TJ_FORCESSE3 TJFLAG_FORCESSE3
  #define TJ_FASTUPSAMPLE TJFLAG_FASTUPSAMPLE
  #define TJ_YUV 512
  
  DLLEXPORT unsigned long DLLCALL TJBUFSIZE(int width, int height);
  
  DLLEXPORT unsigned long DLLCALL TJBUFSIZEYUV(int width, int height,
    int jpegSubsamp);
  
  DLLEXPORT unsigned long DLLCALL tjBufSizeYUV(int width, int height,
    int subsamp);
  
  DLLEXPORT int DLLCALL tjCompress(tjhandle handle, unsigned char *srcBuf,
    int width, int pitch, int height, int pixelSize, unsigned char *dstBuf,
    unsigned long *compressedSize, int jpegSubsamp, int jpegQual, int flags);
  
  DLLEXPORT int DLLCALL tjEncodeYUV(tjhandle handle,
    unsigned char *srcBuf, int width, int pitch, int height, int pixelSize,
    unsigned char *dstBuf, int subsamp, int flags);
  
  DLLEXPORT int DLLCALL tjEncodeYUV2(tjhandle handle,
    unsigned char *srcBuf, int width, int pitch, int height, int pixelFormat,
    unsigned char *dstBuf, int subsamp, int flags);
  
  DLLEXPORT int DLLCALL tjDecompressHeader(tjhandle handle,
    unsigned char *jpegBuf, unsigned long jpegSize, int *width, int *height);
  
  DLLEXPORT int DLLCALL tjDecompressHeader2(tjhandle handle,
    unsigned char *jpegBuf, unsigned long jpegSize, int *width, int *height,
    int *jpegSubsamp);
  
  DLLEXPORT int DLLCALL tjDecompress(tjhandle handle,
    unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf,
    int width, int pitch, int height, int pixelSize, int flags);
  
  DLLEXPORT int DLLCALL tjDecompressToYUV(tjhandle handle,
    unsigned char *jpegBuf, unsigned long jpegSize, unsigned char *dstBuf,
    int flags);
  
  
  /**
   * @}
   */
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif
  