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Created: 2023-05-18 19:08

/src/libjpeg-turbo.main/turbojpeg.h
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/*
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 * Copyright (C)2009-2015, 2017, 2020-2021, 2023 D. R. Commander.
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 *                                               All Rights Reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions are met:
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 *
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 * - Redistributions of source code must retain the above copyright notice,
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 *   this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright notice,
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 *   this list of conditions and the following disclaimer in the documentation
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 *   and/or other materials provided with the distribution.
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 * - Neither the name of the libjpeg-turbo Project nor the names of its
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 *   contributors may be used to endorse or promote products derived from this
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 *   software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS",
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 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
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 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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 * POSSIBILITY OF SUCH DAMAGE.
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 */
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#ifndef __TURBOJPEG_H__
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#define __TURBOJPEG_H__
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#if defined(_WIN32) && defined(DLLDEFINE)
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#define DLLEXPORT  __declspec(dllexport)
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#else
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#define DLLEXPORT
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#endif
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#define DLLCALL
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/**
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 * @addtogroup TurboJPEG
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 * TurboJPEG API.  This API provides an interface for generating, decoding, and
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 * transforming planar YUV and JPEG images in memory.
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 *
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 * @anchor YUVnotes
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 * YUV Image Format Notes
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 * ----------------------
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 * Technically, the JPEG format uses the YCbCr colorspace (which is technically
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 * not a colorspace but a color transform), but per the convention of the
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 * digital video community, the TurboJPEG API uses "YUV" to refer to an image
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 * format consisting of Y, Cb, and Cr image planes.
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 *
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 * Each plane is simply a 2D array of bytes, each byte representing the value
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 * of one of the components (Y, Cb, or Cr) at a particular location in the
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 * image.  The width and height of each plane are determined by the image
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 * width, height, and level of chrominance subsampling.  The luminance plane
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 * width is the image width padded to the nearest multiple of the horizontal
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 * subsampling factor (1 in the case of 4:4:4, grayscale, or 4:4:0; 2 in the
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 * case of 4:2:2 or 4:2:0; 4 in the case of 4:1:1.)  Similarly, the luminance
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 * plane height is the image height padded to the nearest multiple of the
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 * vertical subsampling factor (1 in the case of 4:4:4, 4:2:2, grayscale, or
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 * 4:1:1; 2 in the case of 4:2:0 or 4:4:0.)  This is irrespective of any
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 * additional padding that may be specified as an argument to the various YUV
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 * functions.  The chrominance plane width is equal to the luminance plane
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 * width divided by the horizontal subsampling factor, and the chrominance
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 * plane height is equal to the luminance plane height divided by the vertical
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 * subsampling factor.
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 *
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 * For example, if the source image is 35 x 35 pixels and 4:2:2 subsampling is
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 * used, then the luminance plane would be 36 x 35 bytes, and each of the
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 * chrominance planes would be 18 x 35 bytes.  If you specify a row alignment
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 * of 4 bytes on top of this, then the luminance plane would be 36 x 35 bytes,
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 * and each of the chrominance planes would be 20 x 35 bytes.
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 *
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 * @{
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 */
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/**
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 * The number of chrominance subsampling options
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 */
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401k
#define TJ_NUMSAMP  6
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85
/**
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 * Chrominance subsampling options.
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 * When pixels are converted from RGB to YCbCr (see #TJCS_YCbCr) or from CMYK
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 * to YCCK (see #TJCS_YCCK) as part of the JPEG compression process, some of
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 * the Cb and Cr (chrominance) components can be discarded or averaged together
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 * to produce a smaller image with little perceptible loss of image clarity.
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 * (The human eye is more sensitive to small changes in brightness than to
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 * small changes in color.)  This is called "chrominance subsampling".
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 */
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enum TJSAMP {
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  /**
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   * 4:4:4 chrominance subsampling (no chrominance subsampling).  The JPEG or
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   * YUV image will contain one chrominance component for every pixel in the
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   * source image.
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   */
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  TJSAMP_444 = 0,
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  /**
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   * 4:2:2 chrominance subsampling.  The JPEG or YUV image will contain one
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   * chrominance component for every 2x1 block of pixels in the source image.
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   */
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  TJSAMP_422,
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  /**
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   * 4:2:0 chrominance subsampling.  The JPEG or YUV image will contain one
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   * chrominance component for every 2x2 block of pixels in the source image.
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   */
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  TJSAMP_420,
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  /**
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   * Grayscale.  The JPEG or YUV image will contain no chrominance components.
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   */
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  TJSAMP_GRAY,
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  /**
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   * 4:4:0 chrominance subsampling.  The JPEG or YUV image will contain one
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   * chrominance component for every 1x2 block of pixels in the source image.
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   *
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   * @note 4:4:0 subsampling is not fully accelerated in libjpeg-turbo.
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   */
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  TJSAMP_440,
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  /**
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   * 4:1:1 chrominance subsampling.  The JPEG or YUV image will contain one
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   * chrominance component for every 4x1 block of pixels in the source image.
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   * JPEG images compressed with 4:1:1 subsampling will be almost exactly the
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   * same size as those compressed with 4:2:0 subsampling, and in the
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   * aggregate, both subsampling methods produce approximately the same
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   * perceptual quality.  However, 4:1:1 is better able to reproduce sharp
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   * horizontal features.
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   *
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   * @note 4:1:1 subsampling is not fully accelerated in libjpeg-turbo.
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   */
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  TJSAMP_411
134
};
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/**
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 * MCU block width (in pixels) for a given level of chrominance subsampling.
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 * MCU block sizes:
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 * - 8x8 for no subsampling or grayscale
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 * - 16x8 for 4:2:2
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 * - 8x16 for 4:4:0
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 * - 16x16 for 4:2:0
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 * - 32x8 for 4:1:1
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 */
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static const int tjMCUWidth[TJ_NUMSAMP]  = { 8, 16, 16, 8, 8, 32 };
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/**
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 * MCU block height (in pixels) for a given level of chrominance subsampling.
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 * MCU block sizes:
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 * - 8x8 for no subsampling or grayscale
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 * - 16x8 for 4:2:2
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 * - 8x16 for 4:4:0
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 * - 16x16 for 4:2:0
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 * - 32x8 for 4:1:1
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 */
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static const int tjMCUHeight[TJ_NUMSAMP] = { 8, 8, 16, 8, 16, 8 };
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158
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/**
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 * The number of pixel formats
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 */
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251k
#define TJ_NUMPF  12
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164
/**
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 * Pixel formats
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 */
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enum TJPF {
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  /**
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   * RGB pixel format.  The red, green, and blue components in the image are
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   * stored in 3-byte pixels in the order R, G, B from lowest to highest byte
171
   * address within each pixel.
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   */
173
  TJPF_RGB = 0,
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  /**
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   * BGR pixel format.  The red, green, and blue components in the image are
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   * stored in 3-byte pixels in the order B, G, R from lowest to highest byte
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   * address within each pixel.
178
   */
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  TJPF_BGR,
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  /**
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   * RGBX pixel format.  The red, green, and blue components in the image are
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   * stored in 4-byte pixels in the order R, G, B from lowest to highest byte
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   * address within each pixel.  The X component is ignored when compressing
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   * and undefined when decompressing.
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   */
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  TJPF_RGBX,
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  /**
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   * BGRX pixel format.  The red, green, and blue components in the image are
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   * stored in 4-byte pixels in the order B, G, R from lowest to highest byte
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   * address within each pixel.  The X component is ignored when compressing
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   * and undefined when decompressing.
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   */
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  TJPF_BGRX,
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  /**
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   * XBGR pixel format.  The red, green, and blue components in the image are
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   * stored in 4-byte pixels in the order R, G, B from highest to lowest byte
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   * address within each pixel.  The X component is ignored when compressing
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   * and undefined when decompressing.
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   */
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  TJPF_XBGR,
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  /**
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
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   * address within each pixel.  The X component is ignored when compressing
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   * and undefined when decompressing.
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   */
207
  TJPF_XRGB,
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  /**
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   * Grayscale pixel format.  Each 1-byte pixel represents a luminance
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   * (brightness) level from 0 to 255.
211
   */
212
  TJPF_GRAY,
213
  /**
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   * RGBA pixel format.  This is the same as @ref TJPF_RGBX, except that when
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   * decompressing, the X component is guaranteed to be 0xFF, which can be
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   * interpreted as an opaque alpha channel.
217
   */
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  TJPF_RGBA,
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  /**
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   * BGRA pixel format.  This is the same as @ref TJPF_BGRX, except that when
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   * decompressing, the X component is guaranteed to be 0xFF, which can be
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   * interpreted as an opaque alpha channel.
223
   */
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  TJPF_BGRA,
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  /**
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   * ABGR pixel format.  This is the same as @ref TJPF_XBGR, except that when
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   * decompressing, the X component is guaranteed to be 0xFF, which can be
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   * interpreted as an opaque alpha channel.
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   */
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  TJPF_ABGR,
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  /**
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   * ARGB pixel format.  This is the same as @ref TJPF_XRGB, except that when
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   * decompressing, the X component is guaranteed to be 0xFF, which can be
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   * interpreted as an opaque alpha channel.
235
   */
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  TJPF_ARGB,
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  /**
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   * CMYK pixel format.  Unlike RGB, which is an additive color model used
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   * primarily for display, CMYK (Cyan/Magenta/Yellow/Key) is a subtractive
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   * color model used primarily for printing.  In the CMYK color model, the
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   * value of each color component typically corresponds to an amount of cyan,
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   * magenta, yellow, or black ink that is applied to a white background.  In
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   * order to convert between CMYK and RGB, it is necessary to use a color
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   * management system (CMS.)  A CMS will attempt to map colors within the
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   * printer's gamut to perceptually similar colors in the display's gamut and
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   * vice versa, but the mapping is typically not 1:1 or reversible, nor can it
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   * be defined with a simple formula.  Thus, such a conversion is out of scope
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   * for a codec library.  However, the TurboJPEG API allows for compressing
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   * packed-pixel CMYK images into YCCK JPEG images (see #TJCS_YCCK) and
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   * decompressing YCCK JPEG images into packed-pixel CMYK images.
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   */
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  TJPF_CMYK,
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  /**
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   * Unknown pixel format.  Currently this is only used by #tjLoadImage().
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   */
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  TJPF_UNKNOWN = -1
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};
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/**
260
 * Red offset (in bytes) for a given pixel format.  This specifies the number
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 * of bytes that the red component is offset from the start of the pixel.  For
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 * instance, if a pixel of format TJPF_BGRX is stored in
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 * `unsigned char pixel[]`, then the red component will be
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 *`pixel[tjRedOffset[TJPF_BGRX]]`.  This will be -1 if the pixel format does
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 * not have a red component.
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 */
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static const int tjRedOffset[TJ_NUMPF] = {
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  0, 2, 0, 2, 3, 1, -1, 0, 2, 3, 1, -1
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};
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/**
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 * Green offset (in bytes) for a given pixel format.  This specifies the number
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 * of bytes that the green component is offset from the start of the pixel.
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 * For instance, if a pixel of format TJPF_BGRX is stored in
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 * `unsigned char pixel[]`, then the green component will be
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 * `pixel[tjGreenOffset[TJPF_BGRX]]`.  This will be -1 if the pixel format does
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 * not have a green component.
277
 */
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static const int tjGreenOffset[TJ_NUMPF] = {
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  1, 1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1
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};
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/**
282
 * Blue offset (in bytes) for a given pixel format.  This specifies the number
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 * of bytes that the blue component is offset from the start of the pixel.  For
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 * instance, if a pixel of format TJPF_BGRX is stored in
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 * `unsigned char pixel[]`, then the blue component will be
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 * `pixel[tjBlueOffset[TJPF_BGRX]]`.  This will be -1 if the pixel format does
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 * not have a blue component.
288
 */
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static const int tjBlueOffset[TJ_NUMPF] = {
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  2, 0, 2, 0, 1, 3, -1, 2, 0, 1, 3, -1
291
};
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/**
293
 * Alpha offset (in bytes) for a given pixel format.  This specifies the number
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 * of bytes that the alpha component is offset from the start of the pixel.
295
 * For instance, if a pixel of format TJPF_BGRA is stored in
296
 * `unsigned char pixel[]`, then the alpha component will be
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 * `pixel[tjAlphaOffset[TJPF_BGRA]]`.  This will be -1 if the pixel format does
298
 * not have an alpha component.
299
 */
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static const int tjAlphaOffset[TJ_NUMPF] = {
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  -1, -1, -1, -1, -1, -1, -1, 3, 3, 0, 0, -1
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};
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/**
304
 * Pixel size (in bytes) for a given pixel format
305
 */
306
static const int tjPixelSize[TJ_NUMPF] = {
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  3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 4, 4
308
};
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310
311
/**
312
 * The number of JPEG colorspaces
313
 */
314
#define TJ_NUMCS  5
315
316
/**
317
 * JPEG colorspaces
318
 */
319
enum TJCS {
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  /**
321
   * RGB colorspace.  When compressing the JPEG image, the R, G, and B
322
   * components in the source image are reordered into image planes, but no
323
   * colorspace conversion or subsampling is performed.  RGB JPEG images can be
324
   * decompressed to packed-pixel images with any of the extended RGB or
325
   * grayscale pixel formats, but they cannot be decompressed to planar YUV
326
   * images.
327
   */
328
  TJCS_RGB = 0,
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  /**
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   * YCbCr colorspace.  YCbCr is not an absolute colorspace but rather a
331
   * mathematical transformation of RGB designed solely for storage and
332
   * transmission.  YCbCr images must be converted to RGB before they can
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   * actually be displayed.  In the YCbCr colorspace, the Y (luminance)
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   * component represents the black & white portion of the original image, and
335
   * the Cb and Cr (chrominance) components represent the color portion of the
336
   * original image.  Originally, the analog equivalent of this transformation
337
   * allowed the same signal to drive both black & white and color televisions,
338
   * but JPEG images use YCbCr primarily because it allows the color data to be
339
   * optionally subsampled for the purposes of reducing network or disk usage.
340
   * YCbCr is the most common JPEG colorspace, and YCbCr JPEG images can be
341
   * compressed from and decompressed to packed-pixel images with any of the
342
   * extended RGB or grayscale pixel formats.  YCbCr JPEG images can also be
343
   * compressed from and decompressed to planar YUV images.
344
   */
345
  TJCS_YCbCr,
346
  /**
347
   * Grayscale colorspace.  The JPEG image retains only the luminance data (Y
348
   * component), and any color data from the source image is discarded.
349
   * Grayscale JPEG images can be compressed from and decompressed to
350
   * packed-pixel images with any of the extended RGB or grayscale pixel
351
   * formats, or they can be compressed from and decompressed to planar YUV
352
   * images.
353
   */
354
  TJCS_GRAY,
355
  /**
356
   * CMYK colorspace.  When compressing the JPEG image, the C, M, Y, and K
357
   * components in the source image are reordered into image planes, but no
358
   * colorspace conversion or subsampling is performed.  CMYK JPEG images can
359
   * only be decompressed to packed-pixel images with the CMYK pixel format.
360
   */
361
  TJCS_CMYK,
362
  /**
363
   * YCCK colorspace.  YCCK (AKA "YCbCrK") is not an absolute colorspace but
364
   * rather a mathematical transformation of CMYK designed solely for storage
365
   * and transmission.  It is to CMYK as YCbCr is to RGB.  CMYK pixels can be
366
   * reversibly transformed into YCCK, and as with YCbCr, the chrominance
367
   * components in the YCCK pixels can be subsampled without incurring major
368
   * perceptual loss.  YCCK JPEG images can only be compressed from and
369
   * decompressed to packed-pixel images with the CMYK pixel format.
370
   */
371
  TJCS_YCCK
372
};
373
374
375
/**
376
 * Rows in the packed-pixel source/destination image are stored in bottom-up
377
 * (Windows, OpenGL) order rather than in top-down (X11) order.
378
 */
379
83.9M
#define TJFLAG_BOTTOMUP  2
380
/**
381
 * When decompressing an image that was compressed using chrominance
382
 * subsampling, use the fastest chrominance upsampling algorithm available.
383
 * The default is to use smooth upsampling, which creates a smooth transition
384
 * between neighboring chrominance components in order to reduce upsampling
385
 * artifacts in the decompressed image.
386
 */
387
147k
#define TJFLAG_FASTUPSAMPLE  256
388
/**
389
 * Disable JPEG buffer (re)allocation.  If passed to one of the JPEG
390
 * compression or transform functions, this flag will cause those functions to
391
 * generate an error if the JPEG destination buffer is invalid or too small,
392
 * rather than attempt to allocate or reallocate that buffer.
393
 */
394
0
#define TJFLAG_NOREALLOC  1024
395
/**
396
 * Use the fastest DCT/IDCT algorithm available.  The default if this flag is
397
 * not specified is implementation-specific.  For example, the implementation
398
 * of the TurboJPEG API in libjpeg-turbo uses the fast algorithm by default
399
 * when compressing, because this has been shown to have only a very slight
400
 * effect on accuracy, but it uses the accurate algorithm when decompressing,
401
 * because this has been shown to have a larger effect.
402
 */
403
147k
#define TJFLAG_FASTDCT  2048
404
/**
405
 * Use the most accurate DCT/IDCT algorithm available.  The default if this
406
 * flag is not specified is implementation-specific.  For example, the
407
 * implementation of the TurboJPEG API in libjpeg-turbo uses the fast algorithm
408
 * by default when compressing, because this has been shown to have only a very
409
 * slight effect on accuracy, but it uses the accurate algorithm when
410
 * decompressing, because this has been shown to have a larger effect.
411
 */
412
0
#define TJFLAG_ACCURATEDCT  4096
413
/**
414
 * Immediately discontinue the current compression/decompression/transform
415
 * operation if a warning (non-fatal error) occurs.  The default behavior is to
416
 * allow the operation to complete unless a fatal error is encountered.
417
 */
418
251k
#define TJFLAG_STOPONWARNING  8192
419
/**
420
 * Use progressive entropy coding in JPEG images generated by the compression
421
 * and transform functions.  Progressive entropy coding will generally improve
422
 * compression relative to baseline entropy coding (the default), but it will
423
 * reduce compression and decompression performance considerably.
424
 */
425
0
#define TJFLAG_PROGRESSIVE  16384
426
/**
427
 * Limit the number of progressive JPEG scans that the decompression and
428
 * transform functions will process.  If a progressive JPEG image contains an
429
 * unreasonably large number of scans, then this flag will cause the
430
 * decompression and transform functions to return an error.  The primary
431
 * purpose of this is to allow security-critical applications to guard against
432
 * an exploit of the progressive JPEG format described in
433
 * <a href="https://libjpeg-turbo.org/pmwiki/uploads/About/TwoIssueswiththeJPEGStandard.pdf" target="_blank">this report</a>.
434
 */
435
503k
#define TJFLAG_LIMITSCANS  32768
436
437
438
/**
439
 * The number of error codes
440
 */
441
#define TJ_NUMERR  2
442
443
/**
444
 * Error codes
445
 */
446
enum TJERR {
447
  /**
448
   * The error was non-fatal and recoverable, but the destination image may
449
   * still be corrupt.
450
   */
451
  TJERR_WARNING = 0,
452
  /**
453
   * The error was fatal and non-recoverable.
454
   */
455
  TJERR_FATAL
456
};
457
458
459
/**
460
 * The number of transform operations
461
 */
462
#define TJ_NUMXOP  8
463
464
/**
465
 * Transform operations for #tjTransform()
466
 */
467
enum TJXOP {
468
  /**
469
   * Do not transform the position of the image pixels
470
   */
471
  TJXOP_NONE = 0,
472
  /**
473
   * Flip (mirror) image horizontally.  This transform is imperfect if there
474
   * are any partial MCU blocks on the right edge (see #TJXOPT_PERFECT.)
475
   */
476
  TJXOP_HFLIP,
477
  /**
478
   * Flip (mirror) image vertically.  This transform is imperfect if there are
479
   * any partial MCU blocks on the bottom edge (see #TJXOPT_PERFECT.)
480
   */
481
  TJXOP_VFLIP,
482
  /**
483
   * Transpose image (flip/mirror along upper left to lower right axis.)  This
484
   * transform is always perfect.
485
   */
486
  TJXOP_TRANSPOSE,
487
  /**
488
   * Transverse transpose image (flip/mirror along upper right to lower left
489
   * axis.)  This transform is imperfect if there are any partial MCU blocks in
490
   * the image (see #TJXOPT_PERFECT.)
491
   */
492
  TJXOP_TRANSVERSE,
493
  /**
494
   * Rotate image clockwise by 90 degrees.  This transform is imperfect if
495
   * there are any partial MCU blocks on the bottom edge (see
496
   * #TJXOPT_PERFECT.)
497
   */
498
  TJXOP_ROT90,
499
  /**
500
   * Rotate image 180 degrees.  This transform is imperfect if there are any
501
   * partial MCU blocks in the image (see #TJXOPT_PERFECT.)
502
   */
503
  TJXOP_ROT180,
504
  /**
505
   * Rotate image counter-clockwise by 90 degrees.  This transform is imperfect
506
   * if there are any partial MCU blocks on the right edge (see
507
   * #TJXOPT_PERFECT.)
508
   */
509
  TJXOP_ROT270
510
};
511
512
513
/**
514
 * This option will cause #tjTransform() to return an error if the transform is
515
 * not perfect.  Lossless transforms operate on MCU blocks, whose size depends
516
 * on the level of chrominance subsampling used (see #tjMCUWidth and
517
 * #tjMCUHeight.)  If the image's width or height is not evenly divisible by
518
 * the MCU block size, then there will be partial MCU blocks on the right
519
 * and/or bottom edges.  It is not possible to move these partial MCU blocks to
520
 * the top or left of the image, so any transform that would require that is
521
 * "imperfect."  If this option is not specified, then any partial MCU blocks
522
 * that cannot be transformed will be left in place, which will create
523
 * odd-looking strips on the right or bottom edge of the image.
524
 */
525
0
#define TJXOPT_PERFECT  1
526
/**
527
 * This option will cause #tjTransform() to discard any partial MCU blocks that
528
 * cannot be transformed.
529
 */
530
0
#define TJXOPT_TRIM  2
531
/**
532
 * This option will enable lossless cropping.  See #tjTransform() for more
533
 * information.
534
 */
535
0
#define TJXOPT_CROP  4
536
/**
537
 * This option will discard the color data in the source image and produce a
538
 * grayscale destination image.
539
 */
540
0
#define TJXOPT_GRAY  8
541
/**
542
 * This option will prevent #tjTransform() from outputting a JPEG image for
543
 * this particular transform.  (This can be used in conjunction with a custom
544
 * filter to capture the transformed DCT coefficients without transcoding
545
 * them.)
546
 */
547
0
#define TJXOPT_NOOUTPUT  16
548
/**
549
 * This option will enable progressive entropy coding in the JPEG image
550
 * generated by this particular transform.  Progressive entropy coding will
551
 * generally improve compression relative to baseline entropy coding (the
552
 * default), but it will reduce decompression performance considerably.
553
 */
554
0
#define TJXOPT_PROGRESSIVE  32
555
/**
556
 * This option will prevent #tjTransform() from copying any extra markers
557
 * (including EXIF and ICC profile data) from the source image to the
558
 * destination image.
559
 */
560
0
#define TJXOPT_COPYNONE  64
561
562
563
/**
564
 * Scaling factor
565
 */
566
typedef struct {
567
  /**
568
   * Numerator
569
   */
570
  int num;
571
  /**
572
   * Denominator
573
   */
574
  int denom;
575
} tjscalingfactor;
576
577
/**
578
 * Cropping region
579
 */
580
typedef struct {
581
  /**
582
   * The left boundary of the cropping region.  This must be evenly divisible
583
   * by the MCU block width (see #tjMCUWidth.)
584
   */
585
  int x;
586
  /**
587
   * The upper boundary of the cropping region.  This must be evenly divisible
588
   * by the MCU block height (see #tjMCUHeight.)
589
   */
590
  int y;
591
  /**
592
   * The width of the cropping region.  Setting this to 0 is the equivalent of
593
   * setting it to the width of the source JPEG image - x.
594
   */
595
  int w;
596
  /**
597
   * The height of the cropping region.  Setting this to 0 is the equivalent of
598
   * setting it to the height of the source JPEG image - y.
599
   */
600
  int h;
601
} tjregion;
602
603
/**
604
 * Lossless transform
605
 */
606
typedef struct tjtransform {
607
  /**
608
   * Cropping region
609
   */
610
  tjregion r;
611
  /**
612
   * One of the @ref TJXOP "transform operations"
613
   */
614
  int op;
615
  /**
616
   * The bitwise OR of one of more of the @ref TJXOPT_COPYNONE
617
   * "transform options"
618
   */
619
  int options;
620
  /**
621
   * Arbitrary data that can be accessed within the body of the callback
622
   * function
623
   */
624
  void *data;
625
  /**
626
   * A callback function that can be used to modify the DCT coefficients after
627
   * they are losslessly transformed but before they are transcoded to a new
628
   * JPEG image.  This allows for custom filters or other transformations to be
629
   * applied in the frequency domain.
630
   *
631
   * @param coeffs pointer to an array of transformed DCT coefficients.  (NOTE:
632
   * this pointer is not guaranteed to be valid once the callback returns, so
633
   * applications wishing to hand off the DCT coefficients to another function
634
   * or library should make a copy of them within the body of the callback.)
635
   *
636
   * @param arrayRegion #tjregion structure containing the width and height of
637
   * the array pointed to by `coeffs` as well as its offset relative to the
638
   * component plane.  TurboJPEG implementations may choose to split each
639
   * component plane into multiple DCT coefficient arrays and call the callback
640
   * function once for each array.
641
   *
642
   * @param planeRegion #tjregion structure containing the width and height of
643
   * the component plane to which `coeffs` belongs
644
   *
645
   * @param componentID ID number of the component plane to which `coeffs`
646
   * belongs.  (Y, Cb, and Cr have, respectively, ID's of 0, 1, and 2 in
647
   * typical JPEG images.)
648
   *
649
   * @param transformID ID number of the transformed image to which `coeffs`
650
   * belongs.  This is the same as the index of the transform in the
651
   * `transforms` array that was passed to #tjTransform().
652
   *
653
   * @param transform a pointer to a #tjtransform structure that specifies the
654
   * parameters and/or cropping region for this transform
655
   *
656
   * @return 0 if the callback was successful, or -1 if an error occurred.
657
   */
658
  int (*customFilter) (short *coeffs, tjregion arrayRegion,
659
                       tjregion planeRegion, int componentIndex,
660
                       int transformIndex, struct tjtransform *transform);
661
} tjtransform;
662
663
/**
664
 * TurboJPEG instance handle
665
 */
666
typedef void *tjhandle;
667
668
669
/**
670
 * Pad the given width to the nearest multiple of 4
671
 */
672
#define TJPAD(width)  (((width) + 3) & (~3))
673
674
/**
675
 * Compute the scaled value of `dimension` using the given scaling factor.
676
 * This macro performs the integer equivalent of `ceil(dimension *
677
 * scalingFactor)`.
678
 */
679
#define TJSCALED(dimension, scalingFactor) \
680
5.03M
  (((dimension) * scalingFactor.num + scalingFactor.denom - 1) / \
681
5.03M
   scalingFactor.denom)
682
683
684
#ifdef __cplusplus
685
extern "C" {
686
#endif
687
688
689
/**
690
 * Create a TurboJPEG compressor instance.
691
 *
692
 * @return a handle to the newly-created instance, or NULL if an error occurred
693
 * (see #tjGetErrorStr2().)
694
 */
695
DLLEXPORT tjhandle tjInitCompress(void);
696
697
698
/**
699
 * Compress a packed-pixel RGB, grayscale, or CMYK image into a JPEG image.
700
 *
701
 * @param handle a handle to a TurboJPEG compressor or transformer instance
702
 *
703
 * @param srcBuf pointer to a buffer containing a packed-pixel RGB, grayscale,
704
 * or CMYK source image to be compressed
705
 *
706
 * @param width width (in pixels) of the source image
707
 *
708
 * @param pitch bytes per row in the source image.  Normally this should be
709
 * <tt>width * #tjPixelSize[pixelFormat]</tt>, if the image is unpadded, or
710
 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each row of the image
711
 * is padded to the nearest multiple of 4 bytes, as is the case for Windows
712
 * bitmaps.  You can also be clever and use this parameter to skip rows, etc.
713
 * Setting this parameter to 0 is the equivalent of setting it to
714
 * <tt>width * #tjPixelSize[pixelFormat]</tt>.
715
 *
716
 * @param height height (in pixels) of the source image
717
 *
718
 * @param pixelFormat pixel format of the source image (see @ref TJPF
719
 * "Pixel formats".)
720
 *
721
 * @param jpegBuf address of a pointer to a byte buffer that will receive the
722
 * JPEG image.  TurboJPEG has the ability to reallocate the JPEG buffer to
723
 * accommodate the size of the JPEG image.  Thus, you can choose to:
724
 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
725
 * let TurboJPEG grow the buffer as needed,
726
 * -# set `*jpegBuf` to NULL to tell TurboJPEG to allocate the buffer for you,
727
 * or
728
 * -# pre-allocate the buffer to a "worst case" size determined by calling
729
 * #tjBufSize().  This should ensure that the buffer never has to be
730
 * re-allocated.  (Setting #TJFLAG_NOREALLOC guarantees that it won't be.)
731
 * .
732
 * If you choose option 1, then `*jpegSize` should be set to the size of your
733
 * pre-allocated buffer.  In any case, unless you have set #TJFLAG_NOREALLOC,
734
 * you should always check `*jpegBuf` upon return from this function, as it may
735
 * have changed.
736
 *
737
 * @param jpegSize pointer to an unsigned long variable that holds the size of
738
 * the JPEG buffer.  If `*jpegBuf` points to a pre-allocated buffer, then
739
 * `*jpegSize` should be set to the size of the buffer.  Upon return,
740
 * `*jpegSize` will contain the size of the JPEG image (in bytes.)  If
741
 * `*jpegBuf` points to a JPEG buffer that is being reused from a previous call
742
 * to one of the JPEG compression functions, then `*jpegSize` is ignored.
743
 *
744
 * @param jpegSubsamp the level of chrominance subsampling to be used when
745
 * generating the JPEG image (see @ref TJSAMP
746
 * "Chrominance subsampling options".)
747
 *
748
 * @param jpegQual the image quality of the generated JPEG image (1 = worst,
749
 * 100 = best)
750
 *
751
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
752
 * "flags"
753
 *
754
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
755
 * and #tjGetErrorCode().)
756
 */
757
DLLEXPORT int tjCompress2(tjhandle handle, const unsigned char *srcBuf,
758
                          int width, int pitch, int height, int pixelFormat,
759
                          unsigned char **jpegBuf, unsigned long *jpegSize,
760
                          int jpegSubsamp, int jpegQual, int flags);
761
762
763
/**
764
 * Compress a unified planar YUV image into a JPEG image.
765
 *
766
 * @param handle a handle to a TurboJPEG compressor or transformer instance
767
 *
768
 * @param srcBuf pointer to a buffer containing a unified planar YUV source
769
 * image to be compressed.  The size of this buffer should match the value
770
 * returned by #tjBufSizeYUV2() for the given image width, height, row
771
 * alignment, and level of chrominance subsampling.  The Y, U (Cb), and V (Cr)
772
 * image planes should be stored sequentially in the buffer.  (Refer to
773
 * @ref YUVnotes "YUV Image Format Notes".)
774
 *
775
 * @param width width (in pixels) of the source image.  If the width is not an
776
 * even multiple of the MCU block width (see #tjMCUWidth), then an intermediate
777
 * buffer copy will be performed.
778
 *
779
 * @param align row alignment (in bytes) of the source image (must be a power
780
 * of 2.)  Setting this parameter to n indicates that each row in each plane of
781
 * the source image is padded to the nearest multiple of n bytes
782
 * (1 = unpadded.)
783
 *
784
 * @param height height (in pixels) of the source image.  If the height is not
785
 * an even multiple of the MCU block height (see #tjMCUHeight), then an
786
 * intermediate buffer copy will be performed.
787
 *
788
 * @param subsamp the level of chrominance subsampling used in the source image
789
 * (see @ref TJSAMP "Chrominance subsampling options".)
790
 *
791
 * @param jpegBuf address of a pointer to a byte buffer that will receive the
792
 * JPEG image.  TurboJPEG has the ability to reallocate the JPEG buffer to
793
 * accommodate the size of the JPEG image.  Thus, you can choose to:
794
 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
795
 * let TurboJPEG grow the buffer as needed,
796
 * -# set `*jpegBuf` to NULL to tell TurboJPEG to allocate the buffer for you,
797
 * or
798
 * -# pre-allocate the buffer to a "worst case" size determined by calling
799
 * #tjBufSize().  This should ensure that the buffer never has to be
800
 * re-allocated.  (Setting #TJFLAG_NOREALLOC guarantees that it won't be.)
801
 * .
802
 * If you choose option 1, then `*jpegSize` should be set to the size of your
803
 * pre-allocated buffer.  In any case, unless you have set #TJFLAG_NOREALLOC,
804
 * you should always check `*jpegBuf` upon return from this function, as it may
805
 * have changed.
806
 *
807
 * @param jpegSize pointer to an unsigned long variable that holds the size of
808
 * the JPEG buffer.  If `*jpegBuf` points to a pre-allocated buffer, then
809
 * `*jpegSize` should be set to the size of the buffer.  Upon return,
810
 * `*jpegSize` will contain the size of the JPEG image (in bytes.)  If
811
 * `*jpegBuf` points to a JPEG buffer that is being reused from a previous call
812
 * to one of the JPEG compression functions, then `*jpegSize` is ignored.
813
 *
814
 * @param jpegQual the image quality of the generated JPEG image (1 = worst,
815
 * 100 = best)
816
 *
817
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
818
 * "flags"
819
 *
820
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
821
 * and #tjGetErrorCode().)
822
 */
823
DLLEXPORT int tjCompressFromYUV(tjhandle handle, const unsigned char *srcBuf,
824
                                int width, int align, int height, int subsamp,
825
                                unsigned char **jpegBuf,
826
                                unsigned long *jpegSize, int jpegQual,
827
                                int flags);
828
829
830
/**
831
 * Compress a set of Y, U (Cb), and V (Cr) image planes into a JPEG image.
832
 *
833
 * @param handle a handle to a TurboJPEG compressor or transformer instance
834
 *
835
 * @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
836
 * (or just a Y plane, if compressing a grayscale image) that contain a YUV
837
 * source image to be compressed.  These planes can be contiguous or
838
 * non-contiguous in memory.  The size of each plane should match the value
839
 * returned by #tjPlaneSizeYUV() for the given image width, height, strides,
840
 * and level of chrominance subsampling.  Refer to @ref YUVnotes
841
 * "YUV Image Format Notes" for more details.
842
 *
843
 * @param width width (in pixels) of the source image.  If the width is not an
844
 * even multiple of the MCU block width (see #tjMCUWidth), then an intermediate
845
 * buffer copy will be performed.
846
 *
847
 * @param strides an array of integers, each specifying the number of bytes per
848
 * row in the corresponding plane of the YUV source image.  Setting the stride
849
 * for any plane to 0 is the same as setting it to the plane width (see
850
 * @ref YUVnotes "YUV Image Format Notes".)  If `strides` is NULL, then the
851
 * strides for all planes will be set to their respective plane widths.  You
852
 * can adjust the strides in order to specify an arbitrary amount of row
853
 * padding in each plane or to create a JPEG image from a subregion of a larger
854
 * planar YUV image.
855
 *
856
 * @param height height (in pixels) of the source image.  If the height is not
857
 * an even multiple of the MCU block height (see #tjMCUHeight), then an
858
 * intermediate buffer copy will be performed.
859
 *
860
 * @param subsamp the level of chrominance subsampling used in the source image
861
 * (see @ref TJSAMP "Chrominance subsampling options".)
862
 *
863
 * @param jpegBuf address of a pointer to a byte buffer that will receive the
864
 * JPEG image.  TurboJPEG has the ability to reallocate the JPEG buffer to
865
 * accommodate the size of the JPEG image.  Thus, you can choose to:
866
 * -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
867
 * let TurboJPEG grow the buffer as needed,
868
 * -# set `*jpegBuf` to NULL to tell TurboJPEG to allocate the buffer for you,
869
 * or
870
 * -# pre-allocate the buffer to a "worst case" size determined by calling
871
 * #tjBufSize().  This should ensure that the buffer never has to be
872
 * re-allocated.  (Setting #TJFLAG_NOREALLOC guarantees that it won't be.)
873
 * .
874
 * If you choose option 1, then `*jpegSize` should be set to the size of your
875
 * pre-allocated buffer.  In any case, unless you have set #TJFLAG_NOREALLOC,
876
 * you should always check `*jpegBuf` upon return from this function, as it may
877
 * have changed.
878
 *
879
 * @param jpegSize pointer to an unsigned long variable that holds the size of
880
 * the JPEG buffer.  If `*jpegBuf` points to a pre-allocated buffer, then
881
 * `*jpegSize` should be set to the size of the buffer.  Upon return,
882
 * `*jpegSize` will contain the size of the JPEG image (in bytes.)  If
883
 * `*jpegBuf` points to a JPEG buffer that is being reused from a previous call
884
 * to one of the JPEG compression functions, then `*jpegSize` is ignored.
885
 *
886
 * @param jpegQual the image quality of the generated JPEG image (1 = worst,
887
 * 100 = best)
888
 *
889
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
890
 * "flags"
891
 *
892
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
893
 * and #tjGetErrorCode().)
894
 */
895
DLLEXPORT int tjCompressFromYUVPlanes(tjhandle handle,
896
                                      const unsigned char **srcPlanes,
897
                                      int width, const int *strides,
898
                                      int height, int subsamp,
899
                                      unsigned char **jpegBuf,
900
                                      unsigned long *jpegSize, int jpegQual,
901
                                      int flags);
902
903
904
/**
905
 * The maximum size of the buffer (in bytes) required to hold a JPEG image with
906
 * the given parameters.  The number of bytes returned by this function is
907
 * larger than the size of the uncompressed source image.  The reason for this
908
 * is that the JPEG format uses 16-bit coefficients, so it is possible for a
909
 * very high-quality source image with very high-frequency content to expand
910
 * rather than compress when converted to the JPEG format.  Such images
911
 * represent very rare corner cases, but since there is no way to predict the
912
 * size of a JPEG image prior to compression, the corner cases have to be
913
 * handled.
914
 *
915
 * @param width width (in pixels) of the image
916
 *
917
 * @param height height (in pixels) of the image
918
 *
919
 * @param jpegSubsamp the level of chrominance subsampling to be used when
920
 * generating the JPEG image (see @ref TJSAMP
921
 * "Chrominance subsampling options".)
922
 *
923
 * @return the maximum size of the buffer (in bytes) required to hold the
924
 * image, or -1 if the arguments are out of bounds.
925
 */
926
DLLEXPORT unsigned long tjBufSize(int width, int height, int jpegSubsamp);
927
928
929
/**
930
 * The size of the buffer (in bytes) required to hold a unified planar YUV
931
 * image with the given parameters.
932
 *
933
 * @param width width (in pixels) of the image
934
 *
935
 * @param align row alignment (in bytes) of the image (must be a power of 2.)
936
 * Setting this parameter to n specifies that each row in each plane of the
937
 * image will be padded to the nearest multiple of n bytes (1 = unpadded.)
938
 *
939
 * @param height height (in pixels) of the image
940
 *
941
 * @param subsamp level of chrominance subsampling in the image (see
942
 * @ref TJSAMP "Chrominance subsampling options".)
943
 *
944
 * @return the size of the buffer (in bytes) required to hold the image, or -1
945
 * if the arguments are out of bounds.
946
 */
947
DLLEXPORT unsigned long tjBufSizeYUV2(int width, int align, int height,
948
                                      int subsamp);
949
950
951
/**
952
 * The size of the buffer (in bytes) required to hold a YUV image plane with
953
 * the given parameters.
954
 *
955
 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
956
 *
957
 * @param width width (in pixels) of the YUV image.  NOTE: this is the width of
958
 * the whole image, not the plane width.
959
 *
960
 * @param stride bytes per row in the image plane.  Setting this to 0 is the
961
 * equivalent of setting it to the plane width.
962
 *
963
 * @param height height (in pixels) of the YUV image.  NOTE: this is the height
964
 * of the whole image, not the plane height.
965
 *
966
 * @param subsamp level of chrominance subsampling in the image (see
967
 * @ref TJSAMP "Chrominance subsampling options".)
968
 *
969
 * @return the size of the buffer (in bytes) required to hold the YUV image
970
 * plane, or -1 if the arguments are out of bounds.
971
 */
972
DLLEXPORT unsigned long tjPlaneSizeYUV(int componentID, int width, int stride,
973
                                       int height, int subsamp);
974
975
976
/**
977
 * The plane width of a YUV image plane with the given parameters.  Refer to
978
 * @ref YUVnotes "YUV Image Format Notes" for a description of plane width.
979
 *
980
 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
981
 *
982
 * @param width width (in pixels) of the YUV image
983
 *
984
 * @param subsamp level of chrominance subsampling in the image (see
985
 * @ref TJSAMP "Chrominance subsampling options".)
986
 *
987
 * @return the plane width of a YUV image plane with the given parameters, or
988
 * -1 if the arguments are out of bounds.
989
 */
990
DLLEXPORT int tjPlaneWidth(int componentID, int width, int subsamp);
991
992
993
/**
994
 * The plane height of a YUV image plane with the given parameters.  Refer to
995
 * @ref YUVnotes "YUV Image Format Notes" for a description of plane height.
996
 *
997
 * @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
998
 *
999
 * @param height height (in pixels) of the YUV image
1000
 *
1001
 * @param subsamp level of chrominance subsampling in the image (see
1002
 * @ref TJSAMP "Chrominance subsampling options".)
1003
 *
1004
 * @return the plane height of a YUV image plane with the given parameters, or
1005
 * -1 if the arguments are out of bounds.
1006
 */
1007
DLLEXPORT int tjPlaneHeight(int componentID, int height, int subsamp);
1008
1009
1010
/**
1011
 * Encode a packed-pixel RGB or grayscale image into a unified planar YUV
1012
 * image.  This function performs color conversion (which is accelerated in the
1013
 * libjpeg-turbo implementation) but does not execute any of the other steps in
1014
 * the JPEG compression process.
1015
 *
1016
 * @param handle a handle to a TurboJPEG compressor or transformer instance
1017
 *
1018
 * @param srcBuf pointer to a buffer containing a packed-pixel RGB or grayscale
1019
 * source image to be encoded
1020
 *
1021
 * @param width width (in pixels) of the source image
1022
 *
1023
 * @param pitch bytes per row in the source image.  Normally this should be
1024
 * <tt>width * #tjPixelSize[pixelFormat]</tt>, if the image is unpadded, or
1025
 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each row of the image
1026
 * is padded to the nearest multiple of 4 bytes, as is the case for Windows
1027
 * bitmaps.  You can also be clever and use this parameter to skip rows, etc.
1028
 * Setting this parameter to 0 is the equivalent of setting it to
1029
 * <tt>width * #tjPixelSize[pixelFormat]</tt>.
1030
 *
1031
 * @param height height (in pixels) of the source image
1032
 *
1033
 * @param pixelFormat pixel format of the source image (see @ref TJPF
1034
 * "Pixel formats".)
1035
 *
1036
 * @param dstBuf pointer to a buffer that will receive the unified planar YUV
1037
 * image.  Use #tjBufSizeYUV2() to determine the appropriate size for this
1038
 * buffer based on the image width, height, row alignment, and level of
1039
 * chrominance subsampling.  The Y, U (Cb), and V (Cr) image planes will be
1040
 * stored sequentially in the buffer.  (Refer to @ref YUVnotes
1041
 * "YUV Image Format Notes".)
1042
 *
1043
 * @param align row alignment (in bytes) of the YUV image (must be a power of
1044
 * 2.)  Setting this parameter to n will cause each row in each plane of the
1045
 * YUV image to be padded to the nearest multiple of n bytes (1 = unpadded.)
1046
 * To generate images suitable for X Video, `align` should be set to 4.
1047
 *
1048
 * @param subsamp the level of chrominance subsampling to be used when
1049
 * generating the YUV image (see @ref TJSAMP
1050
 * "Chrominance subsampling options".)  To generate images suitable for X
1051
 * Video, `subsamp` should be set to @ref TJSAMP_420.  This produces an image
1052
 * compatible with the I420 (AKA "YUV420P") format.
1053
 *
1054
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
1055
 * "flags"
1056
 *
1057
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
1058
 * and #tjGetErrorCode().)
1059
 */
1060
DLLEXPORT int tjEncodeYUV3(tjhandle handle, const unsigned char *srcBuf,
1061
                           int width, int pitch, int height, int pixelFormat,
1062
                           unsigned char *dstBuf, int align, int subsamp,
1063
                           int flags);
1064
1065
1066
/**
1067
 * Encode a packed-pixel RGB or grayscale image into separate Y, U (Cb), and
1068
 * V (Cr) image planes.  This function performs color conversion (which is
1069
 * accelerated in the libjpeg-turbo implementation) but does not execute any of
1070
 * the other steps in the JPEG compression process.
1071
 *
1072
 * @param handle a handle to a TurboJPEG compressor or transformer instance
1073
 *
1074
 * @param srcBuf pointer to a buffer containing a packed-pixel RGB or grayscale
1075
 * source image to be encoded
1076
 *
1077
 * @param width width (in pixels) of the source image
1078
 *
1079
 * @param pitch bytes per row in the source image.  Normally this should be
1080
 * <tt>width * #tjPixelSize[pixelFormat]</tt>, if the image is unpadded, or
1081
 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each row of the image
1082
 * is padded to the nearest multiple of 4 bytes, as is the case for Windows
1083
 * bitmaps.  You can also be clever and use this parameter to skip rows, etc.
1084
 * Setting this parameter to 0 is the equivalent of setting it to
1085
 * <tt>width * #tjPixelSize[pixelFormat]</tt>.
1086
 *
1087
 * @param height height (in pixels) of the source image
1088
 *
1089
 * @param pixelFormat pixel format of the source image (see @ref TJPF
1090
 * "Pixel formats".)
1091
 *
1092
 * @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
1093
 * (or just a Y plane, if generating a grayscale image) that will receive the
1094
 * encoded image.  These planes can be contiguous or non-contiguous in memory.
1095
 * Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based
1096
 * on the image width, height, strides, and level of chrominance subsampling.
1097
 * Refer to @ref YUVnotes "YUV Image Format Notes" for more details.
1098
 *
1099
 * @param strides an array of integers, each specifying the number of bytes per
1100
 * row in the corresponding plane of the YUV image.  Setting the stride for any
1101
 * plane to 0 is the same as setting it to the plane width (see @ref YUVnotes
1102
 * "YUV Image Format Notes".)  If `strides` is NULL, then the strides for all
1103
 * planes will be set to their respective plane widths.  You can adjust the
1104
 * strides in order to add an arbitrary amount of row padding to each plane or
1105
 * to encode an RGB or grayscale image into a subregion of a larger planar YUV
1106
 * image.
1107
 *
1108
 * @param subsamp the level of chrominance subsampling to be used when
1109
 * generating the YUV image (see @ref TJSAMP
1110
 * "Chrominance subsampling options".)  To generate images suitable for X
1111
 * Video, `subsamp` should be set to @ref TJSAMP_420.  This produces an image
1112
 * compatible with the I420 (AKA "YUV420P") format.
1113
 *
1114
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
1115
 * "flags"
1116
 *
1117
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
1118
 * and #tjGetErrorCode().)
1119
 */
1120
DLLEXPORT int tjEncodeYUVPlanes(tjhandle handle, const unsigned char *srcBuf,
1121
                                int width, int pitch, int height,
1122
                                int pixelFormat, unsigned char **dstPlanes,
1123
                                int *strides, int subsamp, int flags);
1124
1125
1126
/**
1127
 * Create a TurboJPEG decompressor instance.
1128
 *
1129
 * @return a handle to the newly-created instance, or NULL if an error occurred
1130
 * (see #tjGetErrorStr2().)
1131
 */
1132
DLLEXPORT tjhandle tjInitDecompress(void);
1133
1134
1135
/**
1136
 * Retrieve information about a JPEG image without decompressing it, or prime
1137
 * the decompressor with quantization and Huffman tables.
1138
 *
1139
 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1140
 *
1141
 * @param jpegBuf pointer to a byte buffer containing a JPEG image or an
1142
 * "abbreviated table specification" (AKA "tables-only") datastream.  Passing a
1143
 * tables-only datastream to this function primes the decompressor with
1144
 * quantization and Huffman tables that can be used when decompressing
1145
 * subsequent "abbreviated image" datastreams.  This is useful, for instance,
1146
 * when decompressing video streams in which all frames share the same
1147
 * quantization and Huffman tables.
1148
 *
1149
 * @param jpegSize size of the JPEG image or tables-only datastream (in bytes)
1150
 *
1151
 * @param width pointer to an integer variable that will receive the width (in
1152
 * pixels) of the JPEG image.  If `jpegBuf` points to a tables-only datastream,
1153
 * then `width` is ignored.
1154
 *
1155
 * @param height pointer to an integer variable that will receive the height
1156
 * (in pixels) of the JPEG image.  If `jpegBuf` points to a tables-only
1157
 * datastream, then `height` is ignored.
1158
 *
1159
 * @param jpegSubsamp pointer to an integer variable that will receive the
1160
 * level of chrominance subsampling used when the JPEG image was compressed
1161
 * (see @ref TJSAMP "Chrominance subsampling options".)  If `jpegBuf` points to
1162
 * a tables-only datastream, then `jpegSubsamp` is ignored.
1163
 *
1164
 * @param jpegColorspace pointer to an integer variable that will receive one
1165
 * of the JPEG colorspace constants, indicating the colorspace of the JPEG
1166
 * image (see @ref TJCS "JPEG colorspaces".)  If `jpegBuf` points to a
1167
 * tables-only datastream, then `jpegColorspace` is ignored.
1168
 *
1169
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
1170
 * and #tjGetErrorCode().)
1171
 */
1172
DLLEXPORT int tjDecompressHeader3(tjhandle handle,
1173
                                  const unsigned char *jpegBuf,
1174
                                  unsigned long jpegSize, int *width,
1175
                                  int *height, int *jpegSubsamp,
1176
                                  int *jpegColorspace);
1177
1178
1179
/**
1180
 * Returns a list of fractional scaling factors that the JPEG decompressor
1181
 * supports.
1182
 *
1183
 * @param numScalingFactors pointer to an integer variable that will receive
1184
 * the number of elements in the list
1185
 *
1186
 * @return a pointer to a list of fractional scaling factors, or NULL if an
1187
 * error is encountered (see #tjGetErrorStr2().)
1188
 */
1189
DLLEXPORT tjscalingfactor *tjGetScalingFactors(int *numScalingFactors);
1190
1191
1192
/**
1193
 * Decompress a JPEG image into a packed-pixel RGB, grayscale, or CMYK image.
1194
 *
1195
 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1196
 *
1197
 * @param jpegBuf pointer to a byte buffer containing the JPEG image to
1198
 * decompress
1199
 *
1200
 * @param jpegSize size of the JPEG image (in bytes)
1201
 *
1202
 * @param dstBuf pointer to a buffer that will receive the packed-pixel
1203
 * decompressed image.  This buffer should normally be `pitch * scaledHeight`
1204
 * bytes in size, where `scaledHeight` can be determined by calling #TJSCALED()
1205
 * with the JPEG image height and one of the scaling factors returned by
1206
 * #tjGetScalingFactors().  The `dstBuf` pointer may also be used to decompress
1207
 * into a specific region of a larger buffer.
1208
 *
1209
 * @param width desired width (in pixels) of the destination image.  If this is
1210
 * different than the width of the JPEG image being decompressed, then
1211
 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
1212
 * possible image that will fit within the desired width.  If `width` is set to
1213
 * 0, then only the height will be considered when determining the scaled image
1214
 * size.
1215
 *
1216
 * @param pitch bytes per row in the destination image.  Normally this should
1217
 * be set to <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt>, if the
1218
 * destination image should be unpadded, or
1219
 * <tt>#TJPAD(scaledWidth * #tjPixelSize[pixelFormat])</tt> if each row of the
1220
 * destination image should be padded to the nearest multiple of 4 bytes, as is
1221
 * the case for Windows bitmaps.  (NOTE: `scaledWidth` can be determined by
1222
 * calling #TJSCALED() with the JPEG image width and one of the scaling factors
1223
 * returned by #tjGetScalingFactors().)  You can also be clever and use the
1224
 * pitch parameter to skip rows, etc.  Setting this parameter to 0 is the
1225
 * equivalent of setting it to
1226
 * <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt>.
1227
 *
1228
 * @param height desired height (in pixels) of the destination image.  If this
1229
 * is different than the height of the JPEG image being decompressed, then
1230
 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
1231
 * possible image that will fit within the desired height.  If `height` is set
1232
 * to 0, then only the width will be considered when determining the scaled
1233
 * image size.
1234
 *
1235
 * @param pixelFormat pixel format of the destination image (see @ref
1236
 * TJPF "Pixel formats".)
1237
 *
1238
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
1239
 * "flags"
1240
 *
1241
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
1242
 * and #tjGetErrorCode().)
1243
 */
1244
DLLEXPORT int tjDecompress2(tjhandle handle, const unsigned char *jpegBuf,
1245
                            unsigned long jpegSize, unsigned char *dstBuf,
1246
                            int width, int pitch, int height, int pixelFormat,
1247
                            int flags);
1248
1249
1250
/**
1251
 * Decompress a JPEG image into a unified planar YUV image.  This function
1252
 * performs JPEG decompression but leaves out the color conversion step, so a
1253
 * planar YUV image is generated instead of a packed-pixel image.
1254
 *
1255
 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1256
 *
1257
 * @param jpegBuf pointer to a byte buffer containing the JPEG image to
1258
 * decompress
1259
 *
1260
 * @param jpegSize size of the JPEG image (in bytes)
1261
 *
1262
 * @param dstBuf pointer to a buffer that will receive the unified planar YUV
1263
 * decompressed image.  Use #tjBufSizeYUV2() to determine the appropriate size
1264
 * for this buffer based on the scaled image width, scaled image height, row
1265
 * alignment, and level of chrominance subsampling.  The Y, U (Cb), and V (Cr)
1266
 * image planes will be stored sequentially in the buffer.  (Refer to
1267
 * @ref YUVnotes "YUV Image Format Notes".)
1268
 *
1269
 * @param width desired width (in pixels) of the YUV image.  If this is
1270
 * different than the width of the JPEG image being decompressed, then
1271
 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
1272
 * possible image that will fit within the desired width.  If `width` is set to
1273
 * 0, then only the height will be considered when determining the scaled image
1274
 * size.  If the scaled width is not an even multiple of the MCU block width
1275
 * (see #tjMCUWidth), then an intermediate buffer copy will be performed.
1276
 *
1277
 * @param align row alignment (in bytes) of the YUV image (must be a power of
1278
 * 2.)  Setting this parameter to n will cause each row in each plane of the
1279
 * YUV image to be padded to the nearest multiple of n bytes (1 = unpadded.)
1280
 * To generate images suitable for X Video, `align` should be set to 4.
1281
 *
1282
 * @param height desired height (in pixels) of the YUV image.  If this is
1283
 * different than the height of the JPEG image being decompressed, then
1284
 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
1285
 * possible image that will fit within the desired height.  If `height` is set
1286
 * to 0, then only the width will be considered when determining the scaled
1287
 * image size.  If the scaled height is not an even multiple of the MCU block
1288
 * height (see #tjMCUHeight), then an intermediate buffer copy will be
1289
 * performed.
1290
 *
1291
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
1292
 * "flags"
1293
 *
1294
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
1295
 * and #tjGetErrorCode().)
1296
 */
1297
DLLEXPORT int tjDecompressToYUV2(tjhandle handle, const unsigned char *jpegBuf,
1298
                                 unsigned long jpegSize, unsigned char *dstBuf,
1299
                                 int width, int align, int height, int flags);
1300
1301
1302
/**
1303
 * Decompress a JPEG image into separate Y, U (Cb), and V (Cr) image
1304
 * planes.  This function performs JPEG decompression but leaves out the color
1305
 * conversion step, so a planar YUV image is generated instead of a
1306
 * packed-pixel image.
1307
 *
1308
 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1309
 *
1310
 * @param jpegBuf pointer to a byte buffer containing the JPEG image to
1311
 * decompress
1312
 *
1313
 * @param jpegSize size of the JPEG image (in bytes)
1314
 *
1315
 * @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
1316
 * (or just a Y plane, if decompressing a grayscale image) that will receive
1317
 * the decompressed image.  These planes can be contiguous or non-contiguous in
1318
 * memory.  Use #tjPlaneSizeYUV() to determine the appropriate size for each
1319
 * plane based on the scaled image width, scaled image height, strides, and
1320
 * level of chrominance subsampling.  Refer to @ref YUVnotes
1321
 * "YUV Image Format Notes" for more details.
1322
 *
1323
 * @param width desired width (in pixels) of the YUV image.  If this is
1324
 * different than the width of the JPEG image being decompressed, then
1325
 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
1326
 * possible image that will fit within the desired width.  If `width` is set to
1327
 * 0, then only the height will be considered when determining the scaled image
1328
 * size.  If the scaled width is not an even multiple of the MCU block width
1329
 * (see #tjMCUWidth), then an intermediate buffer copy will be performed.
1330
 *
1331
 * @param strides an array of integers, each specifying the number of bytes per
1332
 * row in the corresponding plane of the YUV image.  Setting the stride for any
1333
 * plane to 0 is the same as setting it to the scaled plane width (see
1334
 * @ref YUVnotes "YUV Image Format Notes".)  If `strides` is NULL, then the
1335
 * strides for all planes will be set to their respective scaled plane widths.
1336
 * You can adjust the strides in order to add an arbitrary amount of row
1337
 * padding to each plane or to decompress the JPEG image into a subregion of a
1338
 * larger planar YUV image.
1339
 *
1340
 * @param height desired height (in pixels) of the YUV image.  If this is
1341
 * different than the height of the JPEG image being decompressed, then
1342
 * TurboJPEG will use scaling in the JPEG decompressor to generate the largest
1343
 * possible image that will fit within the desired height.  If `height` is set
1344
 * to 0, then only the width will be considered when determining the scaled
1345
 * image size.  If the scaled height is not an even multiple of the MCU block
1346
 * height (see #tjMCUHeight), then an intermediate buffer copy will be
1347
 * performed.
1348
 *
1349
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
1350
 * "flags"
1351
 *
1352
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
1353
 * and #tjGetErrorCode().)
1354
 */
1355
DLLEXPORT int tjDecompressToYUVPlanes(tjhandle handle,
1356
                                      const unsigned char *jpegBuf,
1357
                                      unsigned long jpegSize,
1358
                                      unsigned char **dstPlanes, int width,
1359
                                      int *strides, int height, int flags);
1360
1361
1362
/**
1363
 * Decode a unified planar YUV image into a packed-pixel RGB or grayscale
1364
 * image.  This function performs color conversion (which is accelerated in the
1365
 * libjpeg-turbo implementation) but does not execute any of the other steps in
1366
 * the JPEG decompression process.
1367
 *
1368
 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1369
 *
1370
 * @param srcBuf pointer to a buffer containing a unified planar YUV source
1371
 * image to be decoded.  The size of this buffer should match the value
1372
 * returned by #tjBufSizeYUV2() for the given image width, height, row
1373
 * alignment, and level of chrominance subsampling.  The Y, U (Cb), and V (Cr)
1374
 * image planes should be stored sequentially in the source buffer.  (Refer to
1375
 * @ref YUVnotes "YUV Image Format Notes".)
1376
 *
1377
 * @param align row alignment (in bytes) of the YUV source image (must be a
1378
 * power of 2.)  Setting this parameter to n indicates that each row in each
1379
 * plane of the YUV source image is padded to the nearest multiple of n bytes
1380
 * (1 = unpadded.)
1381
 *
1382
 * @param subsamp the level of chrominance subsampling used in the YUV source
1383
 * image (see @ref TJSAMP "Chrominance subsampling options".)
1384
 *
1385
 * @param dstBuf pointer to a buffer that will receive the packed-pixel decoded
1386
 * image.  This buffer should normally be `pitch * height` bytes in size, but
1387
 * the `dstBuf` pointer can also be used to decode into a specific region of a
1388
 * larger buffer.
1389
 *
1390
 * @param width width (in pixels) of the source and destination images
1391
 *
1392
 * @param pitch bytes per row in the destination image.  Normally this should
1393
 * be set to <tt>width * #tjPixelSize[pixelFormat]</tt>, if the destination
1394
 * image should be unpadded, or
1395
 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each row of the
1396
 * destination image should be padded to the nearest multiple of 4 bytes, as is
1397
 * the case for Windows bitmaps.  You can also be clever and use the pitch
1398
 * parameter to skip rows, etc.  Setting this parameter to 0 is the equivalent
1399
 * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.
1400
 *
1401
 * @param height height (in pixels) of the source and destination images
1402
 *
1403
 * @param pixelFormat pixel format of the destination image (see @ref TJPF
1404
 * "Pixel formats".)
1405
 *
1406
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
1407
 * "flags"
1408
 *
1409
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
1410
 * and #tjGetErrorCode().)
1411
 */
1412
DLLEXPORT int tjDecodeYUV(tjhandle handle, const unsigned char *srcBuf,
1413
                          int align, int subsamp, unsigned char *dstBuf,
1414
                          int width, int pitch, int height, int pixelFormat,
1415
                          int flags);
1416
1417
1418
/**
1419
 * Decode a set of Y, U (Cb), and V (Cr) image planes into a packed-pixel RGB
1420
 * or grayscale image.  This function performs color conversion (which is
1421
 * accelerated in the libjpeg-turbo implementation) but does not execute any of
1422
 * the other steps in the JPEG decompression process.
1423
 *
1424
 * @param handle a handle to a TurboJPEG decompressor or transformer instance
1425
 *
1426
 * @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
1427
 * (or just a Y plane, if decoding a grayscale image) that contain a YUV image
1428
 * to be decoded.  These planes can be contiguous or non-contiguous in memory.
1429
 * The size of each plane should match the value returned by #tjPlaneSizeYUV()
1430
 * for the given image width, height, strides, and level of chrominance
1431
 * subsampling.  Refer to @ref YUVnotes "YUV Image Format Notes" for more
1432
 * details.
1433
 *
1434
 * @param strides an array of integers, each specifying the number of bytes per
1435
 * row in the corresponding plane of the YUV source image.  Setting the stride
1436
 * for any plane to 0 is the same as setting it to the plane width (see
1437
 * @ref YUVnotes "YUV Image Format Notes".)  If `strides` is NULL, then the
1438
 * strides for all planes will be set to their respective plane widths.  You
1439
 * can adjust the strides in order to specify an arbitrary amount of row
1440
 * padding in each plane or to decode a subregion of a larger planar YUV image.
1441
 *
1442
 * @param subsamp the level of chrominance subsampling used in the YUV source
1443
 * image (see @ref TJSAMP "Chrominance subsampling options".)
1444
 *
1445
 * @param dstBuf pointer to a buffer that will receive the packed-pixel decoded
1446
 * image.  This buffer should normally be `pitch * height` bytes in size, but
1447
 * the `dstBuf` pointer can also be used to decode into a specific region of a
1448
 * larger buffer.
1449
 *
1450
 * @param width width (in pixels) of the source and destination images
1451
 *
1452
 * @param pitch bytes per row in the destination image.  Normally this should
1453
 * be set to <tt>width * #tjPixelSize[pixelFormat]</tt>, if the destination
1454
 * image should be unpadded, or
1455
 * <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each row of the
1456
 * destination image should be padded to the nearest multiple of 4 bytes, as is
1457
 * the case for Windows bitmaps.  You can also be clever and use the pitch
1458
 * parameter to skip rows, etc.  Setting this parameter to 0 is the equivalent
1459
 * of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.
1460
 *
1461
 * @param height height (in pixels) of the source and destination images
1462
 *
1463
 * @param pixelFormat pixel format of the destination image (see @ref TJPF
1464
 * "Pixel formats".)
1465
 *
1466
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
1467
 * "flags"
1468
 *
1469
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
1470
 * and #tjGetErrorCode().)
1471
 */
1472
DLLEXPORT int tjDecodeYUVPlanes(tjhandle handle,
1473
                                const unsigned char **srcPlanes,
1474
                                const int *strides, int subsamp,
1475
                                unsigned char *dstBuf, int width, int pitch,
1476
                                int height, int pixelFormat, int flags);
1477
1478
1479
/**
1480
 * Create a new TurboJPEG transformer instance.
1481
 *
1482
 * @return a handle to the newly-created instance, or NULL if an error
1483
 * occurred (see #tjGetErrorStr2().)
1484
 */
1485
DLLEXPORT tjhandle tjInitTransform(void);
1486
1487
1488
/**
1489
 * Losslessly transform a JPEG image into another JPEG image.  Lossless
1490
 * transforms work by moving the raw DCT coefficients from one JPEG image
1491
 * structure to another without altering the values of the coefficients.  While
1492
 * this is typically faster than decompressing the image, transforming it, and
1493
 * re-compressing it, lossless transforms are not free.  Each lossless
1494
 * transform requires reading and performing Huffman decoding on all of the
1495
 * coefficients in the source image, regardless of the size of the destination
1496
 * image.  Thus, this function provides a means of generating multiple
1497
 * transformed images from the same source or applying multiple transformations
1498
 * simultaneously, in order to eliminate the need to read the source
1499
 * coefficients multiple times.
1500
 *
1501
 * @param handle a handle to a TurboJPEG transformer instance
1502
 *
1503
 * @param jpegBuf pointer to a byte buffer containing the JPEG source image to
1504
 * transform
1505
 *
1506
 * @param jpegSize size of the JPEG source image (in bytes)
1507
 *
1508
 * @param n the number of transformed JPEG images to generate
1509
 *
1510
 * @param dstBufs pointer to an array of n byte buffers.  `dstBufs[i]` will
1511
 * receive a JPEG image that has been transformed using the parameters in
1512
 * `transforms[i]`.  TurboJPEG has the ability to reallocate the JPEG
1513
 * destination buffer to accommodate the size of the transformed JPEG image.
1514
 * Thus, you can choose to:
1515
 * -# pre-allocate the JPEG destination buffer with an arbitrary size using
1516
 * #tjAlloc() and let TurboJPEG grow the buffer as needed,
1517
 * -# set `dstBufs[i]` to NULL to tell TurboJPEG to allocate the buffer for
1518
 * you, or
1519
 * -# pre-allocate the buffer to a "worst case" size determined by calling
1520
 * #tjBufSize() with the transformed or cropped width and height.  Under normal
1521
 * circumstances, this should ensure that the buffer never has to be
1522
 * re-allocated.  (Setting #TJFLAG_NOREALLOC guarantees that it won't be.)
1523
 * Note, however, that there are some rare cases (such as transforming images
1524
 * with a large amount of embedded EXIF or ICC profile data) in which the
1525
 * transformed JPEG image will be larger than the worst-case size, and
1526
 * #TJFLAG_NOREALLOC cannot be used in those cases.
1527
 * .
1528
 * If you choose option 1, then `dstSizes[i]` should be set to the size of your
1529
 * pre-allocated buffer.  In any case, unless you have set #TJFLAG_NOREALLOC,
1530
 * you should always check `dstBufs[i]` upon return from this function, as it
1531
 * may have changed.
1532
 *
1533
 * @param dstSizes pointer to an array of n unsigned long variables that will
1534
 * receive the actual sizes (in bytes) of each transformed JPEG image.  If
1535
 * `dstBufs[i]` points to a pre-allocated buffer, then `dstSizes[i]` should be
1536
 * set to the size of the buffer.  Upon return, `dstSizes[i]` will contain the
1537
 * size of the transformed JPEG image (in bytes.)
1538
 *
1539
 * @param transforms pointer to an array of n #tjtransform structures, each of
1540
 * which specifies the transform parameters and/or cropping region for the
1541
 * corresponding transformed JPEG image.
1542
 *
1543
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
1544
 * "flags"
1545
 *
1546
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
1547
 * and #tjGetErrorCode().)
1548
 */
1549
DLLEXPORT int tjTransform(tjhandle handle, const unsigned char *jpegBuf,
1550
                          unsigned long jpegSize, int n,
1551
                          unsigned char **dstBufs, unsigned long *dstSizes,
1552
                          tjtransform *transforms, int flags);
1553
1554
1555
/**
1556
 * Destroy a TurboJPEG compressor, decompressor, or transformer instance.
1557
 *
1558
 * @param handle a handle to a TurboJPEG compressor, decompressor or
1559
 * transformer instance
1560
 *
1561
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2().)
1562
 */
1563
DLLEXPORT int tjDestroy(tjhandle handle);
1564
1565
1566
/**
1567
 * Allocate a byte buffer for use with TurboJPEG.  You should always use this
1568
 * function to allocate the JPEG destination buffer(s) for the compression and
1569
 * transform functions unless you are disabling automatic buffer (re)allocation
1570
 * (by setting #TJFLAG_NOREALLOC.)
1571
 *
1572
 * @param bytes the number of bytes to allocate
1573
 *
1574
 * @return a pointer to a newly-allocated buffer with the specified number of
1575
 * bytes.
1576
 *
1577
 * @sa tjFree()
1578
 */
1579
DLLEXPORT unsigned char *tjAlloc(int bytes);
1580
1581
1582
/**
1583
 * Load a packed-pixel image from disk into memory.
1584
 *
1585
 * @param filename name of a file containing a packed-pixel image in Windows
1586
 * BMP or PBMPLUS (PPM/PGM) format
1587
 *
1588
 * @param width pointer to an integer variable that will receive the width (in
1589
 * pixels) of the packed-pixel image
1590
 *
1591
 * @param align row alignment of the packed-pixel buffer to be returned (must
1592
 * be a power of 2.)  Setting this parameter to n will cause all rows in the
1593
 * buffer to be padded to the nearest multiple of n bytes (1 = unpadded.)
1594
 *
1595
 * @param height pointer to an integer variable that will receive the height
1596
 * (in pixels) of the packed-pixel image
1597
 *
1598
 * @param pixelFormat pointer to an integer variable that specifies or will
1599
 * receive the pixel format of the packed-pixel buffer.  The behavior of
1600
 * #tjLoadImage() will vary depending on the value of `*pixelFormat` passed to
1601
 * the function:
1602
 * - @ref TJPF_UNKNOWN : The packed-pixel buffer returned by this function will
1603
 * use the most optimal pixel format for the file type, and `*pixelFormat` will
1604
 * contain the ID of that pixel format upon successful return from this
1605
 * function.
1606
 * - @ref TJPF_GRAY : Only PGM files and 8-bit-per-pixel BMP files with a
1607
 * grayscale colormap can be loaded.
1608
 * - @ref TJPF_CMYK : The RGB or grayscale pixels stored in the file will be
1609
 * converted using a quick & dirty algorithm that is suitable only for testing
1610
 * purposes.  (Proper conversion between CMYK and other formats requires a
1611
 * color management system.)
1612
 * - Other @ref TJPF "pixel formats" : The packed-pixel buffer will use the
1613
 * specified pixel format, and pixel format conversion will be performed if
1614
 * necessary.
1615
 *
1616
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
1617
 * "flags".
1618
 *
1619
 * @return a pointer to a newly-allocated buffer containing the packed-pixel
1620
 * image, converted to the chosen pixel format and with the chosen row
1621
 * alignment, or NULL if an error occurred (see #tjGetErrorStr2().)  This
1622
 * buffer should be freed using #tjFree().
1623
 */
1624
DLLEXPORT unsigned char *tjLoadImage(const char *filename, int *width,
1625
                                     int align, int *height, int *pixelFormat,
1626
                                     int flags);
1627
1628
1629
/**
1630
 * Save a packed-pixel image from memory to disk.
1631
 *
1632
 * @param filename name of a file to which to save the packed-pixel image.  The
1633
 * image will be stored in Windows BMP or PBMPLUS (PPM/PGM) format, depending
1634
 * on the file extension.
1635
 *
1636
 * @param buffer pointer to a buffer containing a packed-pixel RGB, grayscale,
1637
 * or CMYK image to be saved
1638
 *
1639
 * @param width width (in pixels) of the packed-pixel image
1640
 *
1641
 * @param pitch bytes per row in the packed-pixel image.  Setting this
1642
 * parameter to 0 is the equivalent of setting it to
1643
 * <tt>width * #tjPixelSize[pixelFormat]</tt>.
1644
 *
1645
 * @param height height (in pixels) of the packed-pixel image
1646
 *
1647
 * @param pixelFormat pixel format of the packed-pixel image (see @ref TJPF
1648
 * "Pixel formats".)  If this parameter is set to @ref TJPF_GRAY, then the
1649
 * image will be stored in PGM or 8-bit-per-pixel (indexed color) BMP format.
1650
 * Otherwise, the image will be stored in PPM or 24-bit-per-pixel BMP format.
1651
 * If this parameter is set to @ref TJPF_CMYK, then the CMYK pixels will be
1652
 * converted to RGB using a quick & dirty algorithm that is suitable only for
1653
 * testing purposes.  (Proper conversion between CMYK and other formats
1654
 * requires a color management system.)
1655
 *
1656
 * @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
1657
 * "flags".
1658
 *
1659
 * @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2().)
1660
 */
1661
DLLEXPORT int tjSaveImage(const char *filename, unsigned char *buffer,
1662
                          int width, int pitch, int height, int pixelFormat,
1663
                          int flags);
1664
1665
1666
/**
1667
 * Free a byte buffer previously allocated by TurboJPEG.  You should always use
1668
 * this function to free JPEG destination buffer(s) that were automatically
1669
 * (re)allocated by the compression and transform functions or that were
1670
 * manually allocated using #tjAlloc().
1671
 *
1672
 * @param buffer address of the buffer to free.  If the address is NULL, then
1673
 * this function has no effect.
1674
 *
1675
 * @sa tjAlloc()
1676
 */
1677
DLLEXPORT void tjFree(unsigned char *buffer);
1678
1679
1680
/**
1681
 * Returns a descriptive error message explaining why the last command failed.
1682
 *
1683
 * @param handle a handle to a TurboJPEG compressor, decompressor, or
1684
 * transformer instance, or NULL if the error was generated by a global
1685
 * function (but note that retrieving the error message for a global function
1686
 * is thread-safe only on platforms that support thread-local storage.)
1687
 *
1688
 * @return a descriptive error message explaining why the last command failed.
1689
 */
1690
DLLEXPORT char *tjGetErrorStr2(tjhandle handle);
1691
1692
1693
/**
1694
 * Returns a code indicating the severity of the last error.  See
1695
 * @ref TJERR "Error codes".
1696
 *
1697
 * @param handle a handle to a TurboJPEG compressor, decompressor or
1698
 * transformer instance
1699
 *
1700
 * @return a code indicating the severity of the last error.  See
1701
 * @ref TJERR "Error codes".
1702
 */
1703
DLLEXPORT int tjGetErrorCode(tjhandle handle);
1704
1705
1706
/* Backward compatibility functions and macros (nothing to see here) */
1707
1708
/* TurboJPEG 1.0+ */
1709
1710
#define NUMSUBOPT  TJ_NUMSAMP
1711
#define TJ_444  TJSAMP_444
1712
#define TJ_422  TJSAMP_422
1713
#define TJ_420  TJSAMP_420
1714
#define TJ_411  TJSAMP_420
1715
#define TJ_GRAYSCALE  TJSAMP_GRAY
1716
1717
0
#define TJ_BGR  1
1718
#define TJ_BOTTOMUP  TJFLAG_BOTTOMUP
1719
#define TJ_FORCEMMX  TJFLAG_FORCEMMX
1720
#define TJ_FORCESSE  TJFLAG_FORCESSE
1721
#define TJ_FORCESSE2  TJFLAG_FORCESSE2
1722
0
#define TJ_ALPHAFIRST  64
1723
#define TJ_FORCESSE3  TJFLAG_FORCESSE3
1724
#define TJ_FASTUPSAMPLE  TJFLAG_FASTUPSAMPLE
1725
1726
DLLEXPORT unsigned long TJBUFSIZE(int width, int height);
1727
1728
DLLEXPORT int tjCompress(tjhandle handle, unsigned char *srcBuf, int width,
1729
                         int pitch, int height, int pixelSize,
1730
                         unsigned char *dstBuf, unsigned long *compressedSize,
1731
                         int jpegSubsamp, int jpegQual, int flags);
1732
1733
DLLEXPORT int tjDecompress(tjhandle handle, unsigned char *jpegBuf,
1734
                           unsigned long jpegSize, unsigned char *dstBuf,
1735
                           int width, int pitch, int height, int pixelSize,
1736
                           int flags);
1737
1738
DLLEXPORT int tjDecompressHeader(tjhandle handle, unsigned char *jpegBuf,
1739
                                 unsigned long jpegSize, int *width,
1740
                                 int *height);
1741
1742
DLLEXPORT char *tjGetErrorStr(void);
1743
1744
/* TurboJPEG 1.1+ */
1745
1746
0
#define TJ_YUV  512
1747
1748
DLLEXPORT unsigned long TJBUFSIZEYUV(int width, int height, int jpegSubsamp);
1749
1750
DLLEXPORT int tjDecompressHeader2(tjhandle handle, unsigned char *jpegBuf,
1751
                                  unsigned long jpegSize, int *width,
1752
                                  int *height, int *jpegSubsamp);
1753
1754
DLLEXPORT int tjDecompressToYUV(tjhandle handle, unsigned char *jpegBuf,
1755
                                unsigned long jpegSize, unsigned char *dstBuf,
1756
                                int flags);
1757
1758
DLLEXPORT int tjEncodeYUV(tjhandle handle, unsigned char *srcBuf, int width,
1759
                          int pitch, int height, int pixelSize,
1760
                          unsigned char *dstBuf, int subsamp, int flags);
1761
1762
/* TurboJPEG 1.2+ */
1763
1764
251k
#define TJFLAG_FORCEMMX  8
1765
251k
#define TJFLAG_FORCESSE  16
1766
251k
#define TJFLAG_FORCESSE2  32
1767
#define TJFLAG_FORCESSE3  128
1768
1769
DLLEXPORT unsigned long tjBufSizeYUV(int width, int height, int subsamp);
1770
1771
DLLEXPORT int tjEncodeYUV2(tjhandle handle, unsigned char *srcBuf, int width,
1772
                           int pitch, int height, int pixelFormat,
1773
                           unsigned char *dstBuf, int subsamp, int flags);
1774
1775
/**
1776
 * @}
1777
 */
1778
1779
#ifdef __cplusplus
1780
}
1781
#endif
1782
1783
#endif