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/*
* Copyright (C)2009-2015, 2017, 2020-2023 D. R. Commander.
* All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name of the libjpeg-turbo Project nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS",
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
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#ifndef __TURBOJPEG_H__
#define __TURBOJPEG_H__
#include <stddef.h>
#if defined(_WIN32) && defined(DLLDEFINE)
#define DLLEXPORT __declspec(dllexport)
#else
#define DLLEXPORT
#endif
#define DLLCALL
/**
* @addtogroup TurboJPEG
* TurboJPEG API. This API provides an interface for generating, decoding, and
* transforming planar YUV and JPEG images in memory.
*
* @anchor YUVnotes
* YUV Image Format Notes
* ----------------------
* Technically, the JPEG format uses the YCbCr colorspace (which is technically
* not a colorspace but a color transform), but per the convention of the
* digital video community, the TurboJPEG API uses "YUV" to refer to an image
* format consisting of Y, Cb, and Cr image planes.
*
* Each plane is simply a 2D array of bytes, each byte representing the value
* of one of the components (Y, Cb, or Cr) at a particular location in the
* image. The width and height of each plane are determined by the image
* width, height, and level of chrominance subsampling. The luminance plane
* width is the image width padded to the nearest multiple of the horizontal
* subsampling factor (1 in the case of 4:4:4, grayscale, 4:4:0, or 4:4:1; 2 in
* the case of 4:2:2 or 4:2:0; 4 in the case of 4:1:1.) Similarly, the
* luminance plane height is the image height padded to the nearest multiple of
* the vertical subsampling factor (1 in the case of 4:4:4, 4:2:2, grayscale,
* or 4:1:1; 2 in the case of 4:2:0 or 4:4:0; 4 in the case of 4:4:1.) This is
* irrespective of any additional padding that may be specified as an argument
* to the various YUV functions. The chrominance plane width is equal to the
* luminance plane width divided by the horizontal subsampling factor, and the
* chrominance plane height is equal to the luminance plane height divided by
* the vertical subsampling factor.
*
* For example, if the source image is 35 x 35 pixels and 4:2:2 subsampling is
* used, then the luminance plane would be 36 x 35 bytes, and each of the
* chrominance planes would be 18 x 35 bytes. If you specify a row alignment
* of 4 bytes on top of this, then the luminance plane would be 36 x 35 bytes,
* and each of the chrominance planes would be 20 x 35 bytes.
*
* @{
*/
/**
* The number of initialization options
*/
#define TJ_NUMINIT 3
/**
* Initialization options.
*/
enum TJINIT {
/**
* Initialize the TurboJPEG instance for compression.
*/
TJINIT_COMPRESS,
/**
* Initialize the TurboJPEG instance for decompression.
*/
TJINIT_DECOMPRESS,
/**
* Initialize the TurboJPEG instance for lossless transformation (both
* compression and decompression.)
*/
TJINIT_TRANSFORM
};
/**
* The number of chrominance subsampling options
*/
#define TJ_NUMSAMP 7
/**
* Chrominance subsampling options.
* When pixels are converted from RGB to YCbCr (see #TJCS_YCbCr) or from CMYK
* to YCCK (see #TJCS_YCCK) as part of the JPEG compression process, some of
* the Cb and Cr (chrominance) components can be discarded or averaged together
* to produce a smaller image with little perceptible loss of image clarity.
* (The human eye is more sensitive to small changes in brightness than to
* small changes in color.) This is called "chrominance subsampling".
*/
enum TJSAMP {
/**
* 4:4:4 chrominance subsampling (no chrominance subsampling). The JPEG or
* YUV image will contain one chrominance component for every pixel in the
* source image.
*/
TJSAMP_444,
/**
* 4:2:2 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 2x1 block of pixels in the source image.
*/
TJSAMP_422,
/**
* 4:2:0 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 2x2 block of pixels in the source image.
*/
TJSAMP_420,
/**
* Grayscale. The JPEG or YUV image will contain no chrominance components.
*/
TJSAMP_GRAY,
/**
* 4:4:0 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 1x2 block of pixels in the source image.
*
* @note 4:4:0 subsampling is not fully accelerated in libjpeg-turbo.
*/
TJSAMP_440,
/**
* 4:1:1 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 4x1 block of pixels in the source image.
* JPEG images compressed with 4:1:1 subsampling will be almost exactly the
* same size as those compressed with 4:2:0 subsampling, and in the
* aggregate, both subsampling methods produce approximately the same
* perceptual quality. However, 4:1:1 is better able to reproduce sharp
* horizontal features.
*
* @note 4:1:1 subsampling is not fully accelerated in libjpeg-turbo.
*/
TJSAMP_411,
/**
* 4:4:1 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 1x4 block of pixels in the source image.
* JPEG images compressed with 4:4:1 subsampling will be almost exactly the
* same size as those compressed with 4:2:0 subsampling, and in the
* aggregate, both subsampling methods produce approximately the same
* perceptual quality. However, 4:4:1 is better able to reproduce sharp
* vertical features.
*
* @note 4:4:1 subsampling is not fully accelerated in libjpeg-turbo.
*/
TJSAMP_441,
/**
* Unknown subsampling. The JPEG image uses an unusual type of chrominance
* subsampling. Such images can be decompressed into packed-pixel images,
* but they cannot be
* - decompressed into planar YUV images,
* - losslessly transformed if #TJXOPT_CROP is specified, or
* - partially decompressed using a cropping region.
*/
TJSAMP_UNKNOWN = -1
};
/**
* MCU block width (in pixels) for a given level of chrominance subsampling.
* MCU block sizes:
* - 8x8 for no subsampling or grayscale
* - 16x8 for 4:2:2
* - 8x16 for 4:4:0
* - 16x16 for 4:2:0
* - 32x8 for 4:1:1
* - 8x32 for 4:4:1
*/
static const int tjMCUWidth[TJ_NUMSAMP] = { 8, 16, 16, 8, 8, 32, 8 };
/**
* MCU block height (in pixels) for a given level of chrominance subsampling.
* MCU block sizes:
* - 8x8 for no subsampling or grayscale
* - 16x8 for 4:2:2
* - 8x16 for 4:4:0
* - 16x16 for 4:2:0
* - 32x8 for 4:1:1
* - 8x32 for 4:4:1
*/
static const int tjMCUHeight[TJ_NUMSAMP] = { 8, 8, 16, 8, 16, 8, 32 };
/**
* The number of pixel formats
*/
#define TJ_NUMPF 12
/**
* Pixel formats
*/
enum TJPF {
/**
* RGB pixel format. The red, green, and blue components in the image are
* stored in 3-sample pixels in the order R, G, B from lowest to highest
* memory address within each pixel.
*/
TJPF_RGB,
/**
* BGR pixel format. The red, green, and blue components in the image are
* stored in 3-sample pixels in the order B, G, R from lowest to highest
* memory address within each pixel.
*/
TJPF_BGR,
/**
* RGBX pixel format. The red, green, and blue components in the image are
* stored in 4-sample pixels in the order R, G, B from lowest to highest
* memory address within each pixel. The X component is ignored when
* compressing and undefined when decompressing.
*/
TJPF_RGBX,
/**
* BGRX pixel format. The red, green, and blue components in the image are
* stored in 4-sample pixels in the order B, G, R from lowest to highest
* memory address within each pixel. The X component is ignored when
* compressing and undefined when decompressing.
*/
TJPF_BGRX,
/**
* XBGR pixel format. The red, green, and blue components in the image are
* stored in 4-sample pixels in the order R, G, B from highest to lowest
* memory address within each pixel. The X component is ignored when
* compressing and undefined when decompressing.
*/
TJPF_XBGR,
/**
* XRGB pixel format. The red, green, and blue components in the image are
* stored in 4-sample pixels in the order B, G, R from highest to lowest
* memory address within each pixel. The X component is ignored when
* compressing and undefined when decompressing.
*/
TJPF_XRGB,
/**
* Grayscale pixel format. Each 1-sample pixel represents a luminance
* (brightness) level from 0 to the maximum sample value (255 for 8-bit
* samples, 4095 for 12-bit samples, and 65535 for 16-bit samples.)
*/
TJPF_GRAY,
/**
* RGBA pixel format. This is the same as @ref TJPF_RGBX, except that when
* decompressing, the X component is guaranteed to be equal to the maximum
* sample value, which can be interpreted as an opaque alpha channel.
*/
TJPF_RGBA,
/**
* BGRA pixel format. This is the same as @ref TJPF_BGRX, except that when
* decompressing, the X component is guaranteed to be equal to the maximum
* sample value, which can be interpreted as an opaque alpha channel.
*/
TJPF_BGRA,
/**
* ABGR pixel format. This is the same as @ref TJPF_XBGR, except that when
* decompressing, the X component is guaranteed to be equal to the maximum
* sample value, which can be interpreted as an opaque alpha channel.
*/
TJPF_ABGR,
/**
* ARGB pixel format. This is the same as @ref TJPF_XRGB, except that when
* decompressing, the X component is guaranteed to be equal to the maximum
* sample value, which can be interpreted as an opaque alpha channel.
*/
TJPF_ARGB,
/**
* CMYK pixel format. Unlike RGB, which is an additive color model used
* primarily for display, CMYK (Cyan/Magenta/Yellow/Key) is a subtractive
* color model used primarily for printing. In the CMYK color model, the
* value of each color component typically corresponds to an amount of cyan,
* magenta, yellow, or black ink that is applied to a white background. In
* order to convert between CMYK and RGB, it is necessary to use a color
* management system (CMS.) A CMS will attempt to map colors within the
* printer's gamut to perceptually similar colors in the display's gamut and
* vice versa, but the mapping is typically not 1:1 or reversible, nor can it
* be defined with a simple formula. Thus, such a conversion is out of scope
* for a codec library. However, the TurboJPEG API allows for compressing
* packed-pixel CMYK images into YCCK JPEG images (see #TJCS_YCCK) and
* decompressing YCCK JPEG images into packed-pixel CMYK images.
*/
TJPF_CMYK,
/**
* Unknown pixel format. Currently this is only used by #tj3LoadImage8(),
* #tj3LoadImage12(), and #tj3LoadImage16().
*/
TJPF_UNKNOWN = -1
};
/**
* Red offset (in samples) for a given pixel format. This specifies the number
* of samples that the red component is offset from the start of the pixel.
* For instance, if an 8-bit-per-component pixel of format TJPF_BGRX is stored
* in `unsigned char pixel[]`, then the red component will be
* `pixel[tjRedOffset[TJPF_BGRX]]`. This will be -1 if the pixel format does
* not have a red component.
*/
static const int tjRedOffset[TJ_NUMPF] = {
0, 2, 0, 2, 3, 1, -1, 0, 2, 3, 1, -1
};
/**
* Green offset (in samples) for a given pixel format. This specifies the
* number of samples that the green component is offset from the start of the
* pixel. For instance, if an 8-bit-per-component pixel of format TJPF_BGRX is
* stored in `unsigned char pixel[]`, then the green component will be
* `pixel[tjGreenOffset[TJPF_BGRX]]`. This will be -1 if the pixel format does
* not have a green component.
*/
static const int tjGreenOffset[TJ_NUMPF] = {
1, 1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1
};
/**
* Blue offset (in samples) for a given pixel format. This specifies the
* number of samples that the blue component is offset from the start of the
* pixel. For instance, if an 8-bit-per-component pixel of format TJPF_BGRX is
* stored in `unsigned char pixel[]`, then the blue component will be
* `pixel[tjBlueOffset[TJPF_BGRX]]`. This will be -1 if the pixel format does
* not have a blue component.
*/
static const int tjBlueOffset[TJ_NUMPF] = {
2, 0, 2, 0, 1, 3, -1, 2, 0, 1, 3, -1
};
/**
* Alpha offset (in samples) for a given pixel format. This specifies the
* number of samples that the alpha component is offset from the start of the
* pixel. For instance, if an 8-bit-per-component pixel of format TJPF_BGRA is
* stored in `unsigned char pixel[]`, then the alpha component will be
* `pixel[tjAlphaOffset[TJPF_BGRA]]`. This will be -1 if the pixel format does
* not have an alpha component.
*/
static const int tjAlphaOffset[TJ_NUMPF] = {
-1, -1, -1, -1, -1, -1, -1, 3, 3, 0, 0, -1
};
/**
* Pixel size (in samples) for a given pixel format
*/
static const int tjPixelSize[TJ_NUMPF] = {
3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 4, 4
};
/**
* The number of JPEG colorspaces
*/
#define TJ_NUMCS 5
/**
* JPEG colorspaces
*/
enum TJCS {
/**
* RGB colorspace. When compressing the JPEG image, the R, G, and B
* components in the source image are reordered into image planes, but no
* colorspace conversion or subsampling is performed. RGB JPEG images can be
* compressed from and decompressed to packed-pixel images with any of the
* extended RGB or grayscale pixel formats, but they cannot be compressed
* from or decompressed to planar YUV images.
*/
TJCS_RGB,
/**
* YCbCr colorspace. YCbCr is not an absolute colorspace but rather a
* mathematical transformation of RGB designed solely for storage and
* transmission. YCbCr images must be converted to RGB before they can
* actually be displayed. In the YCbCr colorspace, the Y (luminance)
* component represents the black & white portion of the original image, and
* the Cb and Cr (chrominance) components represent the color portion of the
* original image. Originally, the analog equivalent of this transformation
* allowed the same signal to drive both black & white and color televisions,
* but JPEG images use YCbCr primarily because it allows the color data to be
* optionally subsampled for the purposes of reducing network or disk usage.
* YCbCr is the most common JPEG colorspace, and YCbCr JPEG images can be
* compressed from and decompressed to packed-pixel images with any of the
* extended RGB or grayscale pixel formats. YCbCr JPEG images can also be
* compressed from and decompressed to planar YUV images.
*/
TJCS_YCbCr,
/**
* Grayscale colorspace. The JPEG image retains only the luminance data (Y
* component), and any color data from the source image is discarded.
* Grayscale JPEG images can be compressed from and decompressed to
* packed-pixel images with any of the extended RGB or grayscale pixel
* formats, or they can be compressed from and decompressed to planar YUV
* images.
*/
TJCS_GRAY,
/**
* CMYK colorspace. When compressing the JPEG image, the C, M, Y, and K
* components in the source image are reordered into image planes, but no
* colorspace conversion or subsampling is performed. CMYK JPEG images can
* only be compressed from and decompressed to packed-pixel images with the
* CMYK pixel format.
*/
TJCS_CMYK,
/**
* YCCK colorspace. YCCK (AKA "YCbCrK") is not an absolute colorspace but
* rather a mathematical transformation of CMYK designed solely for storage
* and transmission. It is to CMYK as YCbCr is to RGB. CMYK pixels can be
* reversibly transformed into YCCK, and as with YCbCr, the chrominance
* components in the YCCK pixels can be subsampled without incurring major
* perceptual loss. YCCK JPEG images can only be compressed from and
* decompressed to packed-pixel images with the CMYK pixel format.
*/
TJCS_YCCK
};
/**
* Parameters
*/
enum TJPARAM {
/**
* Error handling behavior
*
* **Value**
* - `0` *[default]* Allow the current compression/decompression/transform
* operation to complete unless a fatal error is encountered.
* - `1` Immediately discontinue the current
* compression/decompression/transform operation if a warning (non-fatal
* error) occurs.
*/
TJPARAM_STOPONWARNING,
/**
* Row order in packed-pixel source/destination images
*
* **Value**
* - `0` *[default]* top-down (X11) order
* - `1` bottom-up (Windows, OpenGL) order
*/
TJPARAM_BOTTOMUP,
/**
* JPEG destination buffer (re)allocation [compression, lossless
* transformation]
*
* **Value**
* - `0` *[default]* Attempt to allocate or reallocate the JPEG destination
* buffer as needed.
* - `1` Generate an error if the JPEG destination buffer is invalid or too
* small.
*/
TJPARAM_NOREALLOC,
/**
* Perceptual quality of lossy JPEG images [compression only]
*
* **Value**
* - `1`-`100` (`1` = worst quality but best compression, `100` = best
* quality but worst compression) *[no default; must be explicitly
* specified]*
*/
TJPARAM_QUALITY,
/**
* Chrominance subsampling level
*
* The JPEG or YUV image uses (decompression, decoding) or will use (lossy
* compression, encoding) the specified level of chrominance subsampling.
*
* **Value**
* - One of the @ref TJSAMP "chrominance subsampling options" *[no default;
* must be explicitly specified for lossy compression, encoding, and
* decoding]*
*/
TJPARAM_SUBSAMP,
/**
* JPEG width (in pixels) [decompression only, read-only]
*/
TJPARAM_JPEGWIDTH,
/**
* JPEG height (in pixels) [decompression only, read-only]
*/
TJPARAM_JPEGHEIGHT,
/**
* JPEG data precision (bits per sample) [decompression only, read-only]
*
* The JPEG image uses the specified number of bits per sample.
*
* **Value**
* - `8`, `12`, or `16`
*
* 12-bit data precision implies #TJPARAM_OPTIMIZE unless #TJPARAM_ARITHMETIC
* is set.
*/
TJPARAM_PRECISION,
/**
* JPEG colorspace
*
* The JPEG image uses (decompression) or will use (lossy compression) the
* specified colorspace.
*
* **Value**
* - One of the @ref TJCS "JPEG colorspaces" *[default for lossy compression:
* automatically selected based on the subsampling level and pixel format]*
*/
TJPARAM_COLORSPACE,
/**
* Chrominance upsampling algorithm [lossy decompression only]
*
* **Value**
* - `0` *[default]* Use smooth upsampling when decompressing a JPEG image
* that was compressed using chrominance subsampling. This creates a smooth
* transition between neighboring chrominance components in order to reduce
* upsampling artifacts in the decompressed image.
* - `1` Use the fastest chrominance upsampling algorithm available, which
* may combine upsampling with color conversion.
*/
TJPARAM_FASTUPSAMPLE,
/**
* DCT/IDCT algorithm [lossy compression and decompression]
*
* **Value**
* - `0` *[default]* Use the most accurate DCT/IDCT algorithm available.
* - `1` Use the fastest DCT/IDCT algorithm available.
*
* This parameter is provided mainly for backward compatibility with libjpeg,
* which historically implemented several different DCT/IDCT algorithms
* because of performance limitations with 1990s CPUs. In the libjpeg-turbo
* implementation of the TurboJPEG API:
* - The "fast" and "accurate" DCT/IDCT algorithms perform similarly on
* modern x86/x86-64 CPUs that support AVX2 instructions.
* - The "fast" algorithm is generally only about 5-15% faster than the
* "accurate" algorithm on other types of CPUs.
* - The difference in accuracy between the "fast" and "accurate" algorithms
* is the most pronounced at JPEG quality levels above 90 and tends to be
* more pronounced with decompression than with compression.
* - The "fast" algorithm degrades and is not fully accelerated for JPEG
* quality levels above 97, so it will be slower than the "accurate"
* algorithm.
*/
TJPARAM_FASTDCT,
/**
* Optimized baseline entropy coding [lossy compression only]
*
* **Value**
* - `0` *[default]* The JPEG image will use the default Huffman tables.
* - `1` Optimal Huffman tables will be computed for the JPEG image. For
* lossless transformation, this can also be specified using
* #TJXOPT_OPTIMIZE.
*
* Optimized baseline entropy coding will improve compression slightly
* (generally 5% or less), but it will reduce compression performance
* considerably.
*/
TJPARAM_OPTIMIZE,
/**
* Progressive entropy coding
*
* **Value**
* - `0` *[default for compression, lossless transformation]* The lossy JPEG
* image uses (decompression) or will use (compression, lossless
* transformation) baseline entropy coding.
* - `1` The lossy JPEG image uses (decompression) or will use (compression,
* lossless transformation) progressive entropy coding. For lossless
* transformation, this can also be specified using #TJXOPT_PROGRESSIVE.
*
* Progressive entropy coding will generally improve compression relative to
* baseline entropy coding, but it will reduce compression and decompression
* performance considerably. Can be combined with #TJPARAM_ARITHMETIC.
* Implies #TJPARAM_OPTIMIZE unless #TJPARAM_ARITHMETIC is also set.
*/
TJPARAM_PROGRESSIVE,
/**
* Progressive JPEG scan limit for lossy JPEG images [decompression, lossless
* transformation]
*
* Setting this parameter will cause the decompression and transform
* functions to return an error if the number of scans in a progressive JPEG
* image exceeds the specified limit. The primary purpose of this is to
* allow security-critical applications to guard against an exploit of the
* progressive JPEG format described in
* <a href="https://libjpeg-turbo.org/pmwiki/uploads/About/TwoIssueswiththeJPEGStandard.pdf" target="_blank">this report</a>.
*
* **Value**
* - maximum number of progressive JPEG scans that the decompression and
* transform functions will process *[default: `0` (no limit)]*
*
* @see #TJPARAM_PROGRESSIVE
*/
TJPARAM_SCANLIMIT,
/**
* Arithmetic entropy coding
*
* **Value**
* - `0` *[default for compression, lossless transformation]* The lossy JPEG
* image uses (decompression) or will use (compression, lossless
* transformation) Huffman entropy coding.
* - `1` The lossy JPEG image uses (decompression) or will use (compression,
* lossless transformation) arithmetic entropy coding. For lossless
* transformation, this can also be specified using #TJXOPT_ARITHMETIC.
*
* Arithmetic entropy coding will generally improve compression relative to
* Huffman entropy coding, but it will reduce compression and decompression
* performance considerably. Can be combined with #TJPARAM_PROGRESSIVE.
*/
TJPARAM_ARITHMETIC,
/**
* Lossless JPEG
*
* **Value**
* - `0` *[default for compression]* The JPEG image is (decompression) or
* will be (compression) lossy/DCT-based.
* - `1` The JPEG image is (decompression) or will be (compression)
* lossless/predictive.
*
* In most cases, compressing and decompressing lossless JPEG images is
* considerably slower than compressing and decompressing lossy JPEG images,
* and lossless JPEG images are much larger than lossy JPEG images. Thus,
* lossless JPEG images are typically used only for applications that require
* mathematically lossless compression. Also note that the following
* features are not available with lossless JPEG images:
* - Colorspace conversion (lossless JPEG images always use #TJCS_RGB,
* #TJCS_GRAY, or #TJCS_CMYK, depending on the pixel format of the source
* image)
* - Chrominance subsampling (lossless JPEG images always use #TJSAMP_444)
* - JPEG quality selection
* - DCT/IDCT algorithm selection
* - Progressive entropy coding
* - Arithmetic entropy coding
* - Compression from/decompression to planar YUV images
* - Decompression scaling
* - Lossless transformation
*
* @see #TJPARAM_LOSSLESSPSV, #TJPARAM_LOSSLESSPT
*/
TJPARAM_LOSSLESS,
/**
* Lossless JPEG predictor selection value (PSV)
*
* **Value**
* - `1`-`7` *[default for compression: `1`]*
*
* Lossless JPEG compression shares no algorithms with lossy JPEG
* compression. Instead, it uses differential pulse-code modulation (DPCM),
* an algorithm whereby each sample is encoded as the difference between the
* sample's value and a "predictor", which is based on the values of
* neighboring samples. If Ra is the sample immediately to the left of the
* current sample, Rb is the sample immediately above the current sample, and
* Rc is the sample diagonally to the left and above the current sample, then
* the relationship between the predictor selection value and the predictor
* is as follows:
*
* PSV | Predictor
* ----|----------
* 1 | Ra
* 2 | Rb
* 3 | Rc
* 4 | Ra + Rb – Rc
* 5 | Ra + (Rb – Rc) / 2
* 6 | Rb + (Ra – Rc) / 2
* 7 | (Ra + Rb) / 2
*
* Predictors 1-3 are 1-dimensional predictors, whereas Predictors 4-7 are
* 2-dimensional predictors. The best predictor for a particular image
* depends on the image.
*
* @see #TJPARAM_LOSSLESS
*/
TJPARAM_LOSSLESSPSV,
/**
* Lossless JPEG point transform (Pt)
*
* **Value**
* - `0` through ***precision*** *- 1*, where ***precision*** is the JPEG
* data precision in bits *[default for compression: `0`]*
*
* A point transform value of `0` is necessary in order to generate a fully
* lossless JPEG image. (A non-zero point transform value right-shifts the
* input samples by the specified number of bits, which is effectively a form
* of lossy color quantization.)
*
* @see #TJPARAM_LOSSLESS, #TJPARAM_PRECISION
*/
TJPARAM_LOSSLESSPT,
/**
* JPEG restart marker interval in MCU blocks (lossy) or samples (lossless)
* [compression only]
*
* The nature of entropy coding is such that a corrupt JPEG image cannot
* be decompressed beyond the point of corruption unless it contains restart
* markers. A restart marker stops and restarts the entropy coding algorithm
* so that, if a JPEG image is corrupted, decompression can resume at the
* next marker. Thus, adding more restart markers improves the fault
* tolerance of the JPEG image, but adding too many restart markers can
* adversely affect the compression ratio and performance.
*
* **Value**
* - the number of MCU blocks or samples between each restart marker
* *[default: `0` (no restart markers)]*
*
* Setting this parameter to a non-zero value sets #TJPARAM_RESTARTROWS to 0.
*/
TJPARAM_RESTARTBLOCKS,
/**
* JPEG restart marker interval in MCU rows (lossy) or sample rows (lossless)
* [compression only]
*
* See #TJPARAM_RESTARTBLOCKS for a description of restart markers.
*
* **Value**
* - the number of MCU rows or sample rows between each restart marker
* *[default: `0` (no restart markers)]*
*
* Setting this parameter to a non-zero value sets #TJPARAM_RESTARTBLOCKS to
* 0.
*/
TJPARAM_RESTARTROWS,
/**
* JPEG horizontal pixel density
*
* **Value**
* - The JPEG image has (decompression) or will have (compression) the
* specified horizontal pixel density *[default for compression: `1`]*.
*
* This value is stored in or read from the JPEG header. It does not affect
* the contents of the JPEG image. Note that this parameter is set by
* #tj3LoadImage8() when loading a Windows BMP file that contains pixel
* density information, and the value of this parameter is stored to a
* Windows BMP file by #tj3SaveImage8() if the value of #TJPARAM_DENSITYUNITS
* is `2`.
*
* @see TJPARAM_DENSITYUNITS
*/
TJPARAM_XDENSITY,
/**
* JPEG vertical pixel density
*
* **Value**
* - The JPEG image has (decompression) or will have (compression) the
* specified vertical pixel density *[default for compression: `1`]*.
*
* This value is stored in or read from the JPEG header. It does not affect
* the contents of the JPEG image. Note that this parameter is set by
* #tj3LoadImage8() when loading a Windows BMP file that contains pixel
* density information, and the value of this parameter is stored to a
* Windows BMP file by #tj3SaveImage8() if the value of #TJPARAM_DENSITYUNITS
* is `2`.
*
* @see TJPARAM_DENSITYUNITS
*/
TJPARAM_YDENSITY,
/**
* JPEG pixel density units
*
* **Value**
* - `0` *[default for compression]* The pixel density of the JPEG image is
* expressed (decompression) or will be expressed (compression) in unknown
* units.
* - `1` The pixel density of the JPEG image is expressed (decompression) or
* will be expressed (compression) in units of pixels/inch.
* - `2` The pixel density of the JPEG image is expressed (decompression) or
* will be expressed (compression) in units of pixels/cm.
*
* This value is stored in or read from the JPEG header. It does not affect
* the contents of the JPEG image. Note that this parameter is set by
* #tj3LoadImage8() when loading a Windows BMP file that contains pixel
* density information, and the value of this parameter is stored to a
* Windows BMP file by #tj3SaveImage8() if the value is `2`.
*
* @see TJPARAM_XDENSITY, TJPARAM_YDENSITY
*/
TJPARAM_DENSITYUNITS,
/**
* Memory limit for intermediate buffers
*
* **Value**
* - the maximum amount of memory (in megabytes) that will be allocated for
* intermediate buffers, which are used with progressive JPEG compression and
* decompression, optimized baseline entropy coding, lossless JPEG
* compression, and lossless transformation *[default: `0` (no limit)]*
*/
TJPARAM_MAXMEMORY,
/**
* Image size limit [decompression, lossless transformation, packed-pixel
* image loading]
*
* Setting this parameter will cause the decompression, transform, and image
* loading functions to return an error if the number of pixels in the source
* image exceeds the specified limit. This allows security-critical
* applications to guard against excessive memory consumption.
*
* **Value**
* - maximum number of pixels that the decompression, transform, and image
* loading functions will process *[default: `0` (no limit)]*
*/
TJPARAM_MAXPIXELS
};
/**
* The number of error codes
*/
#define TJ_NUMERR 2
/**
* Error codes
*/
enum TJERR {
/**
* The error was non-fatal and recoverable, but the destination image may
* still be corrupt.
*/
TJERR_WARNING,
/**
* The error was fatal and non-recoverable.
*/
TJERR_FATAL
};
/**
* The number of transform operations
*/
#define TJ_NUMXOP 8
/**
* Transform operations for #tj3Transform()
*/
enum TJXOP {
/**
* Do not transform the position of the image pixels
*/
TJXOP_NONE,
/**
* Flip (mirror) image horizontally. This transform is imperfect if there
* are any partial MCU blocks on the right edge (see #TJXOPT_PERFECT.)
*/
TJXOP_HFLIP,
/**
* Flip (mirror) image vertically. This transform is imperfect if there are
* any partial MCU blocks on the bottom edge (see #TJXOPT_PERFECT.)
*/
TJXOP_VFLIP,
/**
* Transpose image (flip/mirror along upper left to lower right axis.) This
* transform is always perfect.
*/
TJXOP_TRANSPOSE,
/**
* Transverse transpose image (flip/mirror along upper right to lower left
* axis.) This transform is imperfect if there are any partial MCU blocks in
* the image (see #TJXOPT_PERFECT.)
*/
TJXOP_TRANSVERSE,
/**
* Rotate image clockwise by 90 degrees. This transform is imperfect if
* there are any partial MCU blocks on the bottom edge (see
* #TJXOPT_PERFECT.)
*/
TJXOP_ROT90,
/**
* Rotate image 180 degrees. This transform is imperfect if there are any
* partial MCU blocks in the image (see #TJXOPT_PERFECT.)
*/
TJXOP_ROT180,
/**
* Rotate image counter-clockwise by 90 degrees. This transform is imperfect
* if there are any partial MCU blocks on the right edge (see
* #TJXOPT_PERFECT.)
*/
TJXOP_ROT270
};
/**
* This option will cause #tj3Transform() to return an error if the transform
* is not perfect. Lossless transforms operate on MCU blocks, whose size
* depends on the level of chrominance subsampling used (see #tjMCUWidth and
* #tjMCUHeight.) If the image's width or height is not evenly divisible by
* the MCU block size, then there will be partial MCU blocks on the right
* and/or bottom edges. It is not possible to move these partial MCU blocks to
* the top or left of the image, so any transform that would require that is
* "imperfect." If this option is not specified, then any partial MCU blocks
* that cannot be transformed will be left in place, which will create
* odd-looking strips on the right or bottom edge of the image.
*/
#define TJXOPT_PERFECT (1 << 0)
/**
* This option will cause #tj3Transform() to discard any partial MCU blocks
* that cannot be transformed.
*/
#define TJXOPT_TRIM (1 << 1)
/**
* This option will enable lossless cropping. See #tj3Transform() for more
* information.
*/
#define TJXOPT_CROP (1 << 2)
/**
* This option will discard the color data in the source image and produce a
* grayscale destination image.
*/
#define TJXOPT_GRAY (1 << 3)
/**
* This option will prevent #tj3Transform() from outputting a JPEG image for
* this particular transform. (This can be used in conjunction with a custom
* filter to capture the transformed DCT coefficients without transcoding
* them.)
*/
#define TJXOPT_NOOUTPUT (1 << 4)
/**
* This option will enable progressive entropy coding in the JPEG image
* generated by this particular transform. Progressive entropy coding will
* generally improve compression relative to baseline entropy coding (the
* default), but it will reduce decompression performance considerably.
* Can be combined with #TJXOPT_ARITHMETIC. Implies #TJXOPT_OPTIMIZE unless
* #TJXOPT_ARITHMETIC is also specified.
*/
#define TJXOPT_PROGRESSIVE (1 << 5)
/**
* This option will prevent #tj3Transform() from copying any extra markers
* (including EXIF and ICC profile data) from the source image to the
* destination image.
*/
#define TJXOPT_COPYNONE (1 << 6)
/**
* This option will enable arithmetic entropy coding in the JPEG image
* generated by this particular transform. Arithmetic entropy coding will
* generally improve compression relative to Huffman entropy coding (the
* default), but it will reduce decompression performance considerably. Can be
* combined with #TJXOPT_PROGRESSIVE.
*/
#define TJXOPT_ARITHMETIC (1 << 7)
/**
* This option will enable optimized baseline entropy coding in the JPEG image
* generated by this particular transform. Optimized baseline entropy coding
* will improve compression slightly (generally 5% or less.)
*/
#define TJXOPT_OPTIMIZE (1 << 8)
/**
* Scaling factor
*/
typedef struct {
/**
* Numerator
*/
int num;
/**
* Denominator
*/
int denom;
} tjscalingfactor;
/**
* Cropping region
*/
typedef struct {
/**
* The left boundary of the cropping region. This must be evenly divisible
* by the MCU block width (see #tjMCUWidth.)
*/
int x;
/**
* The upper boundary of the cropping region. For lossless transformation,
* this must be evenly divisible by the MCU block height (see #tjMCUHeight.)
*/
int y;
/**
* The width of the cropping region. Setting this to 0 is the equivalent of
* setting it to the width of the source JPEG image - x.
*/
int w;
/**
* The height of the cropping region. Setting this to 0 is the equivalent of
* setting it to the height of the source JPEG image - y.
*/
int h;
} tjregion;
/**
* A #tjregion structure that specifies no cropping
*/
static const tjregion TJUNCROPPED = { 0, 0, 0, 0 };
/**
* Lossless transform
*/
typedef struct tjtransform {
/**
* Cropping region
*/
tjregion r;
/**
* One of the @ref TJXOP "transform operations"
*/
int op;
/**
* The bitwise OR of one of more of the @ref TJXOPT_ARITHMETIC
* "transform options"
*/
int options;
/**
* Arbitrary data that can be accessed within the body of the callback
* function
*/
void *data;
/**
* A callback function that can be used to modify the DCT coefficients after
* they are losslessly transformed but before they are transcoded to a new
* JPEG image. This allows for custom filters or other transformations to be
* applied in the frequency domain.
*
* @param coeffs pointer to an array of transformed DCT coefficients. (NOTE:
* this pointer is not guaranteed to be valid once the callback returns, so
* applications wishing to hand off the DCT coefficients to another function
* or library should make a copy of them within the body of the callback.)
*
* @param arrayRegion #tjregion structure containing the width and height of
* the array pointed to by `coeffs` as well as its offset relative to the
* component plane. TurboJPEG implementations may choose to split each
* component plane into multiple DCT coefficient arrays and call the callback
* function once for each array.
*
* @param planeRegion #tjregion structure containing the width and height of
* the component plane to which `coeffs` belongs
*
* @param componentID ID number of the component plane to which `coeffs`
* belongs. (Y, Cb, and Cr have, respectively, ID's of 0, 1, and 2 in
* typical JPEG images.)
*
* @param transformID ID number of the transformed image to which `coeffs`
* belongs. This is the same as the index of the transform in the
* `transforms` array that was passed to #tj3Transform().
*
* @param transform a pointer to a #tjtransform structure that specifies the
* parameters and/or cropping region for this transform
*
* @return 0 if the callback was successful, or -1 if an error occurred.
*/
int (*customFilter) (short *coeffs, tjregion arrayRegion,
tjregion planeRegion, int componentID, int transformID,
struct tjtransform *transform);
} tjtransform;
/**
* TurboJPEG instance handle
*/
typedef void *tjhandle;
/**
* Compute the scaled value of `dimension` using the given scaling factor.
* This macro performs the integer equivalent of `ceil(dimension *
* scalingFactor)`.
*/
#define TJSCALED(dimension, scalingFactor) \
(((dimension) * scalingFactor.num + scalingFactor.denom - 1) / \
scalingFactor.denom)
/**
* A #tjscalingfactor structure that specifies a scaling factor of 1/1 (no
* scaling)
*/
static const tjscalingfactor TJUNSCALED = { 1, 1 };
#ifdef __cplusplus
extern "C" {
#endif
/**
* Create a new TurboJPEG instance.
*
* @param initType one of the @ref TJINIT "initialization options"
*
* @return a handle to the newly-created instance, or NULL if an error occurred
* (see #tj3GetErrorStr().)
*/
DLLEXPORT tjhandle tj3Init(int initType);
/**
* Set the value of a parameter.
*
* @param handle handle to a TurboJPEG instance
*
* @param param one of the @ref TJPARAM "parameters"
*
* @param value value of the parameter (refer to @ref TJPARAM
* "parameter documentation")
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr().)
*/
DLLEXPORT int tj3Set(tjhandle handle, int param, int value);
/**
* Get the value of a parameter.
*
* @param handle handle to a TurboJPEG instance
*
* @param param one of the @ref TJPARAM "parameters"
*
* @return the value of the specified parameter, or -1 if the value is unknown.
*/
DLLEXPORT int tj3Get(tjhandle handle, int param);
/**
* Compress an 8-bit-per-sample packed-pixel RGB, grayscale, or CMYK image into
* an 8-bit-per-sample JPEG image.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* compression
*
* @param srcBuf pointer to a buffer containing a packed-pixel RGB, grayscale,
* or CMYK source image to be compressed. This buffer should normally be
* `pitch * height` samples in size. However, you can also use this parameter
* to compress from a specific region of a larger buffer.
*
* @param width width (in pixels) of the source image
*
* @param pitch samples per row in the source image. Normally this should be
* <tt>width * #tjPixelSize[pixelFormat]</tt>, if the image is unpadded.
* (Setting this parameter to 0 is the equivalent of setting it to
* <tt>width * #tjPixelSize[pixelFormat]</tt>.) However, you can also use this
* parameter to specify the row alignment/padding of the source image, to skip
* rows, or to compress from a specific region of a larger buffer.
*
* @param height height (in pixels) of the source image
*
* @param pixelFormat pixel format of the source image (see @ref TJPF
* "Pixel formats".)
*
* @param jpegBuf address of a pointer to a byte buffer that will receive the
* JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to
* accommodate the size of the JPEG image. Thus, you can choose to:
* -# pre-allocate the JPEG buffer with an arbitrary size using #tj3Alloc() and
* let TurboJPEG grow the buffer as needed,
* -# set `*jpegBuf` to NULL to tell TurboJPEG to allocate the buffer for you,
* or
* -# pre-allocate the buffer to a "worst case" size determined by calling
* #tj3JPEGBufSize(). This should ensure that the buffer never has to be
* re-allocated. (Setting #TJPARAM_NOREALLOC guarantees that it won't be.)
* .
* If you choose option 1, then `*jpegSize` should be set to the size of your
* pre-allocated buffer. In any case, unless you have set #TJPARAM_NOREALLOC,
* you should always check `*jpegBuf` upon return from this function, as it may
* have changed.
*
* @param jpegSize pointer to a size_t variable that holds the size of the JPEG
* buffer. If `*jpegBuf` points to a pre-allocated buffer, then `*jpegSize`
* should be set to the size of the buffer. Upon return, `*jpegSize` will
* contain the size of the JPEG image (in bytes.) If `*jpegBuf` points to a
* JPEG buffer that is being reused from a previous call to one of the JPEG
* compression functions, then `*jpegSize` is ignored.
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3Compress8(tjhandle handle, const unsigned char *srcBuf,
int width, int pitch, int height, int pixelFormat,
unsigned char **jpegBuf, size_t *jpegSize);
/**
* Compress a 12-bit-per-sample packed-pixel RGB, grayscale, or CMYK image into
* a 12-bit-per-sample JPEG image.
*
* \details \copydetails tj3Compress8()
*/
DLLEXPORT int tj3Compress12(tjhandle handle, const short *srcBuf, int width,
int pitch, int height, int pixelFormat,
unsigned char **jpegBuf, size_t *jpegSize);
/**
* Compress a 16-bit-per-sample packed-pixel RGB, grayscale, or CMYK image into
* a 16-bit-per-sample lossless JPEG image.
*
* \details \copydetails tj3Compress8()
*/
DLLEXPORT int tj3Compress16(tjhandle handle, const unsigned short *srcBuf,
int width, int pitch, int height, int pixelFormat,
unsigned char **jpegBuf, size_t *jpegSize);
/**
* Compress an 8-bit-per-sample unified planar YUV image into an
* 8-bit-per-sample JPEG image.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* compression
*
* @param srcBuf pointer to a buffer containing a unified planar YUV source
* image to be compressed. The size of this buffer should match the value
* returned by #tj3YUVBufSize() for the given image width, height, row
* alignment, and level of chrominance subsampling (see #TJPARAM_SUBSAMP.) The
* Y, U (Cb), and V (Cr) image planes should be stored sequentially in the
* buffer. (Refer to @ref YUVnotes "YUV Image Format Notes".)
*
* @param width width (in pixels) of the source image. If the width is not an
* even multiple of the MCU block width (see #tjMCUWidth), then an intermediate
* buffer copy will be performed.
*
* @param align row alignment (in bytes) of the source image (must be a power
* of 2.) Setting this parameter to n indicates that each row in each plane of
* the source image is padded to the nearest multiple of n bytes
* (1 = unpadded.)
*
* @param height height (in pixels) of the source image. If the height is not
* an even multiple of the MCU block height (see #tjMCUHeight), then an
* intermediate buffer copy will be performed.
*
* @param jpegBuf address of a pointer to a byte buffer that will receive the
* JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to
* accommodate the size of the JPEG image. Thus, you can choose to:
* -# pre-allocate the JPEG buffer with an arbitrary size using #tj3Alloc() and
* let TurboJPEG grow the buffer as needed,
* -# set `*jpegBuf` to NULL to tell TurboJPEG to allocate the buffer for you,
* or
* -# pre-allocate the buffer to a "worst case" size determined by calling
* #tj3JPEGBufSize(). This should ensure that the buffer never has to be
* re-allocated. (Setting #TJPARAM_NOREALLOC guarantees that it won't be.)
* .
* If you choose option 1, then `*jpegSize` should be set to the size of your
* pre-allocated buffer. In any case, unless you have set #TJPARAM_NOREALLOC,
* you should always check `*jpegBuf` upon return from this function, as it may
* have changed.
*
* @param jpegSize pointer to a size_t variable that holds the size of the JPEG
* buffer. If `*jpegBuf` points to a pre-allocated buffer, then `*jpegSize`
* should be set to the size of the buffer. Upon return, `*jpegSize` will
* contain the size of the JPEG image (in bytes.) If `*jpegBuf` points to a
* JPEG buffer that is being reused from a previous call to one of the JPEG
* compression functions, then `*jpegSize` is ignored.
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3CompressFromYUV8(tjhandle handle,
const unsigned char *srcBuf, int width,
int align, int height,
unsigned char **jpegBuf, size_t *jpegSize);
/**
* Compress a set of 8-bit-per-sample Y, U (Cb), and V (Cr) image planes into
* an 8-bit-per-sample JPEG image.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* compression
*
* @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
* (or just a Y plane, if compressing a grayscale image) that contain a YUV
* source image to be compressed. These planes can be contiguous or
* non-contiguous in memory. The size of each plane should match the value
* returned by #tj3YUVPlaneSize() for the given image width, height, strides,
* and level of chrominance subsampling (see #TJPARAM_SUBSAMP.) Refer to
* @ref YUVnotes "YUV Image Format Notes" for more details.
*
* @param width width (in pixels) of the source image. If the width is not an
* even multiple of the MCU block width (see #tjMCUWidth), then an intermediate
* buffer copy will be performed.
*
* @param strides an array of integers, each specifying the number of bytes per
* row in the corresponding plane of the YUV source image. Setting the stride
* for any plane to 0 is the same as setting it to the plane width (see
* @ref YUVnotes "YUV Image Format Notes".) If `strides` is NULL, then the
* strides for all planes will be set to their respective plane widths. You
* can adjust the strides in order to specify an arbitrary amount of row
* padding in each plane or to create a JPEG image from a subregion of a larger
* planar YUV image.
*
* @param height height (in pixels) of the source image. If the height is not
* an even multiple of the MCU block height (see #tjMCUHeight), then an
* intermediate buffer copy will be performed.
*
* @param jpegBuf address of a pointer to a byte buffer that will receive the
* JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to
* accommodate the size of the JPEG image. Thus, you can choose to:
* -# pre-allocate the JPEG buffer with an arbitrary size using #tj3Alloc() and
* let TurboJPEG grow the buffer as needed,
* -# set `*jpegBuf` to NULL to tell TurboJPEG to allocate the buffer for you,
* or
* -# pre-allocate the buffer to a "worst case" size determined by calling
* #tj3JPEGBufSize(). This should ensure that the buffer never has to be
* re-allocated. (Setting #TJPARAM_NOREALLOC guarantees that it won't be.)
* .
* If you choose option 1, then `*jpegSize` should be set to the size of your
* pre-allocated buffer. In any case, unless you have set #TJPARAM_NOREALLOC,
* you should always check `*jpegBuf` upon return from this function, as it may
* have changed.
*
* @param jpegSize pointer to a size_t variable that holds the size of the JPEG
* buffer. If `*jpegBuf` points to a pre-allocated buffer, then `*jpegSize`
* should be set to the size of the buffer. Upon return, `*jpegSize` will
* contain the size of the JPEG image (in bytes.) If `*jpegBuf` points to a
* JPEG buffer that is being reused from a previous call to one of the JPEG
* compression functions, then `*jpegSize` is ignored.
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3CompressFromYUVPlanes8(tjhandle handle,
const unsigned char * const *srcPlanes,
int width, const int *strides,
int height, unsigned char **jpegBuf,
size_t *jpegSize);
/**
* The maximum size of the buffer (in bytes) required to hold a JPEG image with
* the given parameters. The number of bytes returned by this function is
* larger than the size of the uncompressed source image. The reason for this
* is that the JPEG format uses 16-bit coefficients, so it is possible for a
* very high-quality source image with very high-frequency content to expand
* rather than compress when converted to the JPEG format. Such images
* represent very rare corner cases, but since there is no way to predict the
* size of a JPEG image prior to compression, the corner cases have to be
* handled.
*
* @param width width (in pixels) of the image
*
* @param height height (in pixels) of the image
*
* @param jpegSubsamp the level of chrominance subsampling to be used when
* generating the JPEG image (see @ref TJSAMP
* "Chrominance subsampling options".) #TJSAMP_UNKNOWN is treated like
* #TJSAMP_444, since a buffer large enough to hold a JPEG image with no
* subsampling should also be large enough to hold a JPEG image with an
* arbitrary level of subsampling. Note that lossless JPEG images always
* use #TJSAMP_444.
*
* @return the maximum size of the buffer (in bytes) required to hold the
* image, or 0 if the arguments are out of bounds.
*/
DLLEXPORT size_t tj3JPEGBufSize(int width, int height, int jpegSubsamp);
/**
* The size of the buffer (in bytes) required to hold a unified planar YUV
* image with the given parameters.
*
* @param width width (in pixels) of the image
*
* @param align row alignment (in bytes) of the image (must be a power of 2.)
* Setting this parameter to n specifies that each row in each plane of the
* image will be padded to the nearest multiple of n bytes (1 = unpadded.)
*
* @param height height (in pixels) of the image
*
* @param subsamp level of chrominance subsampling in the image (see
* @ref TJSAMP "Chrominance subsampling options".)
*
* @return the size of the buffer (in bytes) required to hold the image, or 0
* if the arguments are out of bounds.
*/
DLLEXPORT size_t tj3YUVBufSize(int width, int align, int height, int subsamp);
/**
* The size of the buffer (in bytes) required to hold a YUV image plane with
* the given parameters.
*
* @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
*
* @param width width (in pixels) of the YUV image. NOTE: this is the width of
* the whole image, not the plane width.
*
* @param stride bytes per row in the image plane. Setting this to 0 is the
* equivalent of setting it to the plane width.
*
* @param height height (in pixels) of the YUV image. NOTE: this is the height
* of the whole image, not the plane height.
*
* @param subsamp level of chrominance subsampling in the image (see
* @ref TJSAMP "Chrominance subsampling options".)
*
* @return the size of the buffer (in bytes) required to hold the YUV image
* plane, or 0 if the arguments are out of bounds.
*/
DLLEXPORT size_t tj3YUVPlaneSize(int componentID, int width, int stride,
int height, int subsamp);
/**
* The plane width of a YUV image plane with the given parameters. Refer to
* @ref YUVnotes "YUV Image Format Notes" for a description of plane width.
*
* @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
*
* @param width width (in pixels) of the YUV image
*
* @param subsamp level of chrominance subsampling in the image (see
* @ref TJSAMP "Chrominance subsampling options".)
*
* @return the plane width of a YUV image plane with the given parameters, or 0
* if the arguments are out of bounds.
*/
DLLEXPORT int tj3YUVPlaneWidth(int componentID, int width, int subsamp);
/**
* The plane height of a YUV image plane with the given parameters. Refer to
* @ref YUVnotes "YUV Image Format Notes" for a description of plane height.
*
* @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
*
* @param height height (in pixels) of the YUV image
*
* @param subsamp level of chrominance subsampling in the image (see
* @ref TJSAMP "Chrominance subsampling options".)
*
* @return the plane height of a YUV image plane with the given parameters, or
* 0 if the arguments are out of bounds.
*/
DLLEXPORT int tj3YUVPlaneHeight(int componentID, int height, int subsamp);
/**
* Encode an 8-bit-per-sample packed-pixel RGB or grayscale image into an
* 8-bit-per-sample unified planar YUV image. This function performs color
* conversion (which is accelerated in the libjpeg-turbo implementation) but
* does not execute any of the other steps in the JPEG compression process.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* compression
*
* @param srcBuf pointer to a buffer containing a packed-pixel RGB or grayscale
* source image to be encoded. This buffer should normally be `pitch * height`
* bytes in size. However, you can also use this parameter to encode from a
* specific region of a larger buffer.
*
* @param width width (in pixels) of the source image
*
* @param pitch bytes per row in the source image. Normally this should be
* <tt>width * #tjPixelSize[pixelFormat]</tt>, if the image is unpadded.
* (Setting this parameter to 0 is the equivalent of setting it to
* <tt>width * #tjPixelSize[pixelFormat]</tt>.) However, you can also use this
* parameter to specify the row alignment/padding of the source image, to skip
* rows, or to encode from a specific region of a larger packed-pixel image.
*
* @param height height (in pixels) of the source image
*
* @param pixelFormat pixel format of the source image (see @ref TJPF
* "Pixel formats".)
*
* @param dstBuf pointer to a buffer that will receive the unified planar YUV
* image. Use #tj3YUVBufSize() to determine the appropriate size for this
* buffer based on the image width, height, row alignment, and level of
* chrominance subsampling (see #TJPARAM_SUBSAMP.) The Y, U (Cb), and V (Cr)
* image planes will be stored sequentially in the buffer. (Refer to
* @ref YUVnotes "YUV Image Format Notes".)
*
* @param align row alignment (in bytes) of the YUV image (must be a power of
* 2.) Setting this parameter to n will cause each row in each plane of the
* YUV image to be padded to the nearest multiple of n bytes (1 = unpadded.)
* To generate images suitable for X Video, `align` should be set to 4.
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3EncodeYUV8(tjhandle handle, const unsigned char *srcBuf,
int width, int pitch, int height, int pixelFormat,
unsigned char *dstBuf, int align);
/**
* Encode an 8-bit-per-sample packed-pixel RGB or grayscale image into separate
* 8-bit-per-sample Y, U (Cb), and V (Cr) image planes. This function performs
* color conversion (which is accelerated in the libjpeg-turbo implementation)
* but does not execute any of the other steps in the JPEG compression process.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* compression
*
* @param srcBuf pointer to a buffer containing a packed-pixel RGB or grayscale
* source image to be encoded. This buffer should normally be `pitch * height`
* bytes in size. However, you can also use this parameter to encode from a
* specific region of a larger buffer.
*
*
* @param width width (in pixels) of the source image
*
* @param pitch bytes per row in the source image. Normally this should be
* <tt>width * #tjPixelSize[pixelFormat]</tt>, if the image is unpadded.
* (Setting this parameter to 0 is the equivalent of setting it to
* <tt>width * #tjPixelSize[pixelFormat]</tt>.) However, you can also use this
* parameter to specify the row alignment/padding of the source image, to skip
* rows, or to encode from a specific region of a larger packed-pixel image.
*
* @param height height (in pixels) of the source image
*
* @param pixelFormat pixel format of the source image (see @ref TJPF
* "Pixel formats".)
*
* @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
* (or just a Y plane, if generating a grayscale image) that will receive the
* encoded image. These planes can be contiguous or non-contiguous in memory.
* Use #tj3YUVPlaneSize() to determine the appropriate size for each plane
* based on the image width, height, strides, and level of chrominance
* subsampling (see #TJPARAM_SUBSAMP.) Refer to @ref YUVnotes
* "YUV Image Format Notes" for more details.
*
* @param strides an array of integers, each specifying the number of bytes per
* row in the corresponding plane of the YUV image. Setting the stride for any
* plane to 0 is the same as setting it to the plane width (see @ref YUVnotes
* "YUV Image Format Notes".) If `strides` is NULL, then the strides for all
* planes will be set to their respective plane widths. You can adjust the
* strides in order to add an arbitrary amount of row padding to each plane or
* to encode an RGB or grayscale image into a subregion of a larger planar YUV
* image.
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3EncodeYUVPlanes8(tjhandle handle, const unsigned char *srcBuf,
int width, int pitch, int height,
int pixelFormat, unsigned char **dstPlanes,
int *strides);
/**
* Retrieve information about a JPEG image without decompressing it, or prime
* the decompressor with quantization and Huffman tables. If a JPEG image is
* passed to this function, then the @ref TJPARAM "parameters" that describe
* the JPEG image will be set when the function returns.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* decompression
*
* @param jpegBuf pointer to a byte buffer containing a JPEG image or an
* "abbreviated table specification" (AKA "tables-only") datastream. Passing a
* tables-only datastream to this function primes the decompressor with
* quantization and Huffman tables that can be used when decompressing
* subsequent "abbreviated image" datastreams. This is useful, for instance,
* when decompressing video streams in which all frames share the same
* quantization and Huffman tables.
*
* @param jpegSize size of the JPEG image or tables-only datastream (in bytes)
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3DecompressHeader(tjhandle handle,
const unsigned char *jpegBuf,
size_t jpegSize);
/**
* Returns a list of fractional scaling factors that the JPEG decompressor
* supports.
*
* @param numScalingFactors pointer to an integer variable that will receive
* the number of elements in the list
*
* @return a pointer to a list of fractional scaling factors, or NULL if an
* error is encountered (see #tj3GetErrorStr().)
*/
DLLEXPORT tjscalingfactor *tj3GetScalingFactors(int *numScalingFactors);
/**
* Set the scaling factor for subsequent lossy decompression operations.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* decompression
*
* @param scalingFactor #tjscalingfactor structure that specifies a fractional
* scaling factor that the decompressor supports (see #tj3GetScalingFactors()),
* or <tt>#TJUNSCALED</tt> for no scaling. Decompression scaling is a function
* of the IDCT algorithm, so scaling factors are generally limited to multiples
* of 1/8. If the entire JPEG image will be decompressed, then the width and
* height of the scaled destination image can be determined by calling
* #TJSCALED() with the JPEG width and height (see #TJPARAM_JPEGWIDTH and
* #TJPARAM_JPEGHEIGHT) and the specified scaling factor. When decompressing
* into a planar YUV image, an intermediate buffer copy will be performed if
* the width or height of the scaled destination image is not an even multiple
* of the MCU block size (see #tjMCUWidth and #tjMCUHeight.) Note that
* decompression scaling is not available (and the specified scaling factor is
* ignored) when decompressing lossless JPEG images (see #TJPARAM_LOSSLESS),
* since the IDCT algorithm is not used with those images. Note also that
* #TJPARAM_FASTDCT is ignored when decompression scaling is enabled.
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr().)
*/
DLLEXPORT int tj3SetScalingFactor(tjhandle handle,
tjscalingfactor scalingFactor);
/**
* Set the cropping region for partially decompressing a lossy JPEG image into
* a packed-pixel image
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* decompression
*
* @param croppingRegion #tjregion structure that specifies a subregion of the
* JPEG image to decompress, or <tt>#TJUNCROPPED</tt> for no cropping. The
* left boundary of the cropping region must be evenly divisible by the scaled
* MCU block width (<tt>#TJSCALED(#tjMCUWidth[subsamp], scalingFactor)</tt>,
* where `subsamp` is the level of chrominance subsampling in the JPEG image
* (see #TJPARAM_SUBSAMP) and `scalingFactor` is the decompression scaling
* factor (see #tj3SetScalingFactor().) The cropping region should be
* specified relative to the scaled image dimensions. Unless `croppingRegion`
* is <tt>#TJUNCROPPED</tt>, the JPEG header must be read (see
* #tj3DecompressHeader()) prior to calling this function.
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr().)
*/
DLLEXPORT int tj3SetCroppingRegion(tjhandle handle, tjregion croppingRegion);
/**
* Decompress an 8-bit-per-sample JPEG image into an 8-bit-per-sample
* packed-pixel RGB, grayscale, or CMYK image. The @ref TJPARAM "parameters"
* that describe the JPEG image will be set when this function returns.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* decompression
*
* @param jpegBuf pointer to a byte buffer containing the JPEG image to
* decompress
*
* @param jpegSize size of the JPEG image (in bytes)
*
* @param dstBuf pointer to a buffer that will receive the packed-pixel
* decompressed image. This buffer should normally be
* `pitch * destinationHeight` samples in size. However, you can also use this
* parameter to decompress into a specific region of a larger buffer. NOTE:
* If the JPEG image is lossy, then `destinationHeight` is either the scaled
* JPEG height (see #TJSCALED(), #TJPARAM_JPEGHEIGHT, and
* #tj3SetScalingFactor()) or the height of the cropping region (see
* #tj3SetCroppingRegion().) If the JPEG image is lossless, then
* `destinationHeight` is the JPEG height.
*
* @param pitch samples per row in the destination image. Normally this should
* be set to <tt>destinationWidth * #tjPixelSize[pixelFormat]</tt>, if the
* destination image should be unpadded. (Setting this parameter to 0 is the
* equivalent of setting it to
* <tt>destinationWidth * #tjPixelSize[pixelFormat]</tt>.) However, you can
* also use this parameter to specify the row alignment/padding of the
* destination image, to skip rows, or to decompress into a specific region of
* a larger buffer. NOTE: If the JPEG image is lossy, then `destinationWidth`
* is either the scaled JPEG width (see #TJSCALED(), #TJPARAM_JPEGWIDTH, and
* #tj3SetScalingFactor()) or the width of the cropping region (see
* #tj3SetCroppingRegion().) If the JPEG image is lossless, then
* `destinationWidth` is the JPEG width.
*
* @param pixelFormat pixel format of the destination image (see @ref
* TJPF "Pixel formats".)
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3Decompress8(tjhandle handle, const unsigned char *jpegBuf,
size_t jpegSize, unsigned char *dstBuf, int pitch,
int pixelFormat);
/**
* Decompress a 12-bit-per-sample JPEG image into a 12-bit-per-sample
* packed-pixel RGB, grayscale, or CMYK image.
*
* \details \copydetails tj3Decompress8()
*/
DLLEXPORT int tj3Decompress12(tjhandle handle, const unsigned char *jpegBuf,
size_t jpegSize, short *dstBuf, int pitch,
int pixelFormat);
/**
* Decompress a 16-bit-per-sample lossless JPEG image into a 16-bit-per-sample
* packed-pixel RGB, grayscale, or CMYK image.
*
* \details \copydetails tj3Decompress8()
*/
DLLEXPORT int tj3Decompress16(tjhandle handle, const unsigned char *jpegBuf,
size_t jpegSize, unsigned short *dstBuf,
int pitch, int pixelFormat);
/**
* Decompress an 8-bit-per-sample JPEG image into an 8-bit-per-sample unified
* planar YUV image. This function performs JPEG decompression but leaves out
* the color conversion step, so a planar YUV image is generated instead of a
* packed-pixel image. The @ref TJPARAM "parameters" that describe the JPEG
* image will be set when this function returns.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* decompression
*
* @param jpegBuf pointer to a byte buffer containing the JPEG image to
* decompress
*
* @param jpegSize size of the JPEG image (in bytes)
*
* @param dstBuf pointer to a buffer that will receive the unified planar YUV
* decompressed image. Use #tj3YUVBufSize() to determine the appropriate size
* for this buffer based on the scaled JPEG width and height (see #TJSCALED(),
* #TJPARAM_JPEGWIDTH, #TJPARAM_JPEGHEIGHT, and #tj3SetScalingFactor()), row
* alignment, and level of chrominance subsampling (see #TJPARAM_SUBSAMP.) The
* Y, U (Cb), and V (Cr) image planes will be stored sequentially in the
* buffer. (Refer to @ref YUVnotes "YUV Image Format Notes".)
*
* @param align row alignment (in bytes) of the YUV image (must be a power of
* 2.) Setting this parameter to n will cause each row in each plane of the
* YUV image to be padded to the nearest multiple of n bytes (1 = unpadded.)
* To generate images suitable for X Video, `align` should be set to 4.
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3DecompressToYUV8(tjhandle handle,
const unsigned char *jpegBuf,
size_t jpegSize,
unsigned char *dstBuf, int align);
/**
* Decompress an 8-bit-per-sample JPEG image into separate 8-bit-per-sample Y,
* U (Cb), and V (Cr) image planes. This function performs JPEG decompression
* but leaves out the color conversion step, so a planar YUV image is generated
* instead of a packed-pixel image. The @ref TJPARAM "parameters" that
* describe the JPEG image will be set when this function returns.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* decompression
*
* @param jpegBuf pointer to a byte buffer containing the JPEG image to
* decompress
*
* @param jpegSize size of the JPEG image (in bytes)
*
* @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
* (or just a Y plane, if decompressing a grayscale image) that will receive
* the decompressed image. These planes can be contiguous or non-contiguous in
* memory. Use #tj3YUVPlaneSize() to determine the appropriate size for each
* plane based on the scaled JPEG width and height (see #TJSCALED(),
* #TJPARAM_JPEGWIDTH, #TJPARAM_JPEGHEIGHT, and #tj3SetScalingFactor()),
* strides, and level of chrominance subsampling (see #TJPARAM_SUBSAMP.) Refer
* to @ref YUVnotes "YUV Image Format Notes" for more details.
*
* @param strides an array of integers, each specifying the number of bytes per
* row in the corresponding plane of the YUV image. Setting the stride for any
* plane to 0 is the same as setting it to the scaled plane width (see
* @ref YUVnotes "YUV Image Format Notes".) If `strides` is NULL, then the
* strides for all planes will be set to their respective scaled plane widths.
* You can adjust the strides in order to add an arbitrary amount of row
* padding to each plane or to decompress the JPEG image into a subregion of a
* larger planar YUV image.
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3DecompressToYUVPlanes8(tjhandle handle,
const unsigned char *jpegBuf,
size_t jpegSize,
unsigned char **dstPlanes,
int *strides);
/**
* Decode an 8-bit-per-sample unified planar YUV image into an 8-bit-per-sample
* packed-pixel RGB or grayscale image. This function performs color
* conversion (which is accelerated in the libjpeg-turbo implementation) but
* does not execute any of the other steps in the JPEG decompression process.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* decompression
*
* @param srcBuf pointer to a buffer containing a unified planar YUV source
* image to be decoded. The size of this buffer should match the value
* returned by #tj3YUVBufSize() for the given image width, height, row
* alignment, and level of chrominance subsampling (see #TJPARAM_SUBSAMP.) The
* Y, U (Cb), and V (Cr) image planes should be stored sequentially in the
* source buffer. (Refer to @ref YUVnotes "YUV Image Format Notes".)
*
* @param align row alignment (in bytes) of the YUV source image (must be a
* power of 2.) Setting this parameter to n indicates that each row in each
* plane of the YUV source image is padded to the nearest multiple of n bytes
* (1 = unpadded.)
*
* @param dstBuf pointer to a buffer that will receive the packed-pixel decoded
* image. This buffer should normally be `pitch * height` bytes in size.
* However, you can also use this parameter to decode into a specific region of
* a larger buffer.
*
* @param width width (in pixels) of the source and destination images
*
* @param pitch bytes per row in the destination image. Normally this should
* be set to <tt>width * #tjPixelSize[pixelFormat]</tt>, if the destination
* image should be unpadded. (Setting this parameter to 0 is the equivalent of
* setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.) However, you can
* also use this parameter to specify the row alignment/padding of the
* destination image, to skip rows, or to decode into a specific region of a
* larger buffer.
*
* @param height height (in pixels) of the source and destination images
*
* @param pixelFormat pixel format of the destination image (see @ref TJPF
* "Pixel formats".)
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3DecodeYUV8(tjhandle handle, const unsigned char *srcBuf,
int align, unsigned char *dstBuf, int width,
int pitch, int height, int pixelFormat);
/**
* Decode a set of 8-bit-per-sample Y, U (Cb), and V (Cr) image planes into an
* 8-bit-per-sample packed-pixel RGB or grayscale image. This function
* performs color conversion (which is accelerated in the libjpeg-turbo
* implementation) but does not execute any of the other steps in the JPEG
* decompression process.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* decompression
*
* @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
* (or just a Y plane, if decoding a grayscale image) that contain a YUV image
* to be decoded. These planes can be contiguous or non-contiguous in memory.
* The size of each plane should match the value returned by #tj3YUVPlaneSize()
* for the given image width, height, strides, and level of chrominance
* subsampling (see #TJPARAM_SUBSAMP.) Refer to @ref YUVnotes
* "YUV Image Format Notes" for more details.
*
* @param strides an array of integers, each specifying the number of bytes per
* row in the corresponding plane of the YUV source image. Setting the stride
* for any plane to 0 is the same as setting it to the plane width (see
* @ref YUVnotes "YUV Image Format Notes".) If `strides` is NULL, then the
* strides for all planes will be set to their respective plane widths. You
* can adjust the strides in order to specify an arbitrary amount of row
* padding in each plane or to decode a subregion of a larger planar YUV image.
*
* @param dstBuf pointer to a buffer that will receive the packed-pixel decoded
* image. This buffer should normally be `pitch * height` bytes in size.
* However, you can also use this parameter to decode into a specific region of
* a larger buffer.
*
* @param width width (in pixels) of the source and destination images
*
* @param pitch bytes per row in the destination image. Normally this should
* be set to <tt>width * #tjPixelSize[pixelFormat]</tt>, if the destination
* image should be unpadded. (Setting this parameter to 0 is the equivalent of
* setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.) However, you can
* also use this parameter to specify the row alignment/padding of the
* destination image, to skip rows, or to decode into a specific region of a
* larger buffer.
*
* @param height height (in pixels) of the source and destination images
*
* @param pixelFormat pixel format of the destination image (see @ref TJPF
* "Pixel formats".)
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3DecodeYUVPlanes8(tjhandle handle,
const unsigned char * const *srcPlanes,
const int *strides, unsigned char *dstBuf,
int width, int pitch, int height,
int pixelFormat);
/**
* Losslessly transform a JPEG image into another JPEG image. Lossless
* transforms work by moving the raw DCT coefficients from one JPEG image
* structure to another without altering the values of the coefficients. While
* this is typically faster than decompressing the image, transforming it, and
* re-compressing it, lossless transforms are not free. Each lossless
* transform requires reading and performing entropy decoding on all of the
* coefficients in the source image, regardless of the size of the destination
* image. Thus, this function provides a means of generating multiple
* transformed images from the same source or applying multiple transformations
* simultaneously, in order to eliminate the need to read the source
* coefficients multiple times.
*
* @param handle handle to a TurboJPEG instance that has been initialized for
* lossless transformation
*
* @param jpegBuf pointer to a byte buffer containing the JPEG source image to
* transform
*
* @param jpegSize size of the JPEG source image (in bytes)
*
* @param n the number of transformed JPEG images to generate
*
* @param dstBufs pointer to an array of n byte buffers. `dstBufs[i]` will
* receive a JPEG image that has been transformed using the parameters in
* `transforms[i]`. TurboJPEG has the ability to reallocate the JPEG
* destination buffer to accommodate the size of the transformed JPEG image.
* Thus, you can choose to:
* -# pre-allocate the JPEG destination buffer with an arbitrary size using
* #tj3Alloc() and let TurboJPEG grow the buffer as needed,
* -# set `dstBufs[i]` to NULL to tell TurboJPEG to allocate the buffer for
* you, or
* -# pre-allocate the buffer to a "worst case" size determined by calling
* #tj3JPEGBufSize() with the transformed or cropped width and height and the
* level of subsampling used in the source image. Under normal circumstances,
* this should ensure that the buffer never has to be re-allocated. (Setting
* #TJPARAM_NOREALLOC guarantees that it won't be.) Note, however, that there
* are some rare cases (such as transforming images with a large amount of
* embedded EXIF or ICC profile data) in which the transformed JPEG image will
* be larger than the worst-case size, and #TJPARAM_NOREALLOC cannot be used in
* those cases.
* .
* If you choose option 1, then `dstSizes[i]` should be set to the size of your
* pre-allocated buffer. In any case, unless you have set #TJPARAM_NOREALLOC,
* you should always check `dstBufs[i]` upon return from this function, as it
* may have changed.
*
* @param dstSizes pointer to an array of n size_t variables that will receive
* the actual sizes (in bytes) of each transformed JPEG image. If `dstBufs[i]`
* points to a pre-allocated buffer, then `dstSizes[i]` should be set to the
* size of the buffer. Upon return, `dstSizes[i]` will contain the size of the
* transformed JPEG image (in bytes.)
*
* @param transforms pointer to an array of n #tjtransform structures, each of
* which specifies the transform parameters and/or cropping region for the
* corresponding transformed JPEG image.
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr()
* and #tj3GetErrorCode().)
*/
DLLEXPORT int tj3Transform(tjhandle handle, const unsigned char *jpegBuf,
size_t jpegSize, int n, unsigned char **dstBufs,
size_t *dstSizes, const tjtransform *transforms);
/**
* Destroy a TurboJPEG instance.
*
* @param handle handle to a TurboJPEG instance. If the handle is NULL, then
* this function has no effect.
*/
DLLEXPORT void tj3Destroy(tjhandle handle);
/**
* Allocate a byte buffer for use with TurboJPEG. You should always use this
* function to allocate the JPEG destination buffer(s) for the compression and
* transform functions unless you are disabling automatic buffer (re)allocation
* (by setting #TJPARAM_NOREALLOC.)
*
* @param bytes the number of bytes to allocate
*
* @return a pointer to a newly-allocated buffer with the specified number of
* bytes.
*
* @see tj3Free()
*/
DLLEXPORT void *tj3Alloc(size_t bytes);
/**
* Load an 8-bit-per-sample packed-pixel image from disk into memory.
*
* @param handle handle to a TurboJPEG instance
*
* @param filename name of a file containing a packed-pixel image in Windows
* BMP or PBMPLUS (PPM/PGM) format. Windows BMP files require 8-bit-per-sample
* data precision. If the data precision of the PBMPLUS file does not match
* the target data precision, then upconverting or downconverting will be
* performed.
*
* @param width pointer to an integer variable that will receive the width (in
* pixels) of the packed-pixel image
*
* @param align row alignment (in samples) of the packed-pixel buffer to be
* returned (must be a power of 2.) Setting this parameter to n will cause all
* rows in the buffer to be padded to the nearest multiple of n samples
* (1 = unpadded.)
*
* @param height pointer to an integer variable that will receive the height
* (in pixels) of the packed-pixel image
*
* @param pixelFormat pointer to an integer variable that specifies or will
* receive the pixel format of the packed-pixel buffer. The behavior of this
* function will vary depending on the value of `*pixelFormat` passed to the
* function:
* - @ref TJPF_UNKNOWN : The packed-pixel buffer returned by this function will
* use the most optimal pixel format for the file type, and `*pixelFormat` will
* contain the ID of that pixel format upon successful return from this
* function.
* - @ref TJPF_GRAY : Only PGM files and 8-bit-per-pixel BMP files with a
* grayscale colormap can be loaded.
* - @ref TJPF_CMYK : The RGB or grayscale pixels stored in the file will be
* converted using a quick & dirty algorithm that is suitable only for testing
* purposes. (Proper conversion between CMYK and other formats requires a
* color management system.)
* - Other @ref TJPF "pixel formats" : The packed-pixel buffer will use the
* specified pixel format, and pixel format conversion will be performed if
* necessary.
*
* @return a pointer to a newly-allocated buffer containing the packed-pixel
* image, converted to the chosen pixel format and with the chosen row
* alignment, or NULL if an error occurred (see #tj3GetErrorStr().) This
* buffer should be freed using #tj3Free().
*/
DLLEXPORT unsigned char *tj3LoadImage8(tjhandle handle, const char *filename,
int *width, int align, int *height,
int *pixelFormat);
/**
* Load a 12-bit-per-sample packed-pixel image from disk into memory.
*
* \details \copydetails tj3LoadImage8()
*/
DLLEXPORT short *tj3LoadImage12(tjhandle handle, const char *filename,
int *width, int align, int *height,
int *pixelFormat);
/**
* Load a 16-bit-per-sample packed-pixel image from disk into memory.
*
* \details \copydetails tj3LoadImage8()
*/
DLLEXPORT unsigned short *tj3LoadImage16(tjhandle handle, const char *filename,
int *width, int align, int *height,
int *pixelFormat);
/**
* Save an 8-bit-per-sample packed-pixel image from memory to disk.
*
* @param handle handle to a TurboJPEG instance
*
* @param filename name of a file to which to save the packed-pixel image. The
* image will be stored in Windows BMP or PBMPLUS (PPM/PGM) format, depending
* on the file extension. Windows BMP files require 8-bit-per-sample data
* precision.
*
* @param buffer pointer to a buffer containing a packed-pixel RGB, grayscale,
* or CMYK image to be saved
*
* @param width width (in pixels) of the packed-pixel image
*
* @param pitch samples per row in the packed-pixel image. Setting this
* parameter to 0 is the equivalent of setting it to
* <tt>width * #tjPixelSize[pixelFormat]</tt>.
*
* @param height height (in pixels) of the packed-pixel image
*
* @param pixelFormat pixel format of the packed-pixel image (see @ref TJPF
* "Pixel formats".) If this parameter is set to @ref TJPF_GRAY, then the
* image will be stored in PGM or 8-bit-per-pixel (indexed color) BMP format.
* Otherwise, the image will be stored in PPM or 24-bit-per-pixel BMP format.
* If this parameter is set to @ref TJPF_CMYK, then the CMYK pixels will be
* converted to RGB using a quick & dirty algorithm that is suitable only for
* testing purposes. (Proper conversion between CMYK and other formats
* requires a color management system.)
*
* @return 0 if successful, or -1 if an error occurred (see #tj3GetErrorStr().)
*/
DLLEXPORT int tj3SaveImage8(tjhandle handle, const char *filename,
const unsigned char *buffer, int width, int pitch,
int height, int pixelFormat);
/**
* Save a 12-bit-per-sample packed-pixel image from memory to disk.
*
* \details \copydetails tj3SaveImage8()
*/
DLLEXPORT int tj3SaveImage12(tjhandle handle, const char *filename,
const short *buffer, int width, int pitch,
int height, int pixelFormat);
/**
* Save a 16-bit-per-sample packed-pixel image from memory to disk.
*
* \details \copydetails tj3SaveImage8()
*/
DLLEXPORT int tj3SaveImage16(tjhandle handle, const char *filename,
const unsigned short *buffer, int width,
int pitch, int height, int pixelFormat);
/**
* Free a byte buffer previously allocated by TurboJPEG. You should always use
* this function to free JPEG destination buffer(s) that were automatically
* (re)allocated by the compression and transform functions or that were
* manually allocated using #tj3Alloc().
*
* @param buffer address of the buffer to free. If the address is NULL, then
* this function has no effect.
*
* @see tj3Alloc()
*/
DLLEXPORT void tj3Free(void *buffer);
/**
* Returns a descriptive error message explaining why the last command failed.
*
* @param handle handle to a TurboJPEG instance, or NULL if the error was
* generated by a global function (but note that retrieving the error message
* for a global function is thread-safe only on platforms that support
* thread-local storage.)
*
* @return a descriptive error message explaining why the last command failed.
*/
DLLEXPORT char *tj3GetErrorStr(tjhandle handle);
/**
* Returns a code indicating the severity of the last error. See
* @ref TJERR "Error codes".
*
* @param handle handle to a TurboJPEG instance
*
* @return a code indicating the severity of the last error. See
* @ref TJERR "Error codes".
*/
DLLEXPORT int tj3GetErrorCode(tjhandle handle);
/* Backward compatibility functions and macros (nothing to see here) */
/* TurboJPEG 1.0+ */
#define NUMSUBOPT TJ_NUMSAMP
#define TJ_444 TJSAMP_444
#define TJ_422 TJSAMP_422
#define TJ_420 TJSAMP_420
#define TJ_411 TJSAMP_420
#define TJ_GRAYSCALE TJSAMP_GRAY
#define TJ_BGR 1
#define TJ_BOTTOMUP TJFLAG_BOTTOMUP
#define TJ_FORCEMMX TJFLAG_FORCEMMX
#define TJ_FORCESSE TJFLAG_FORCESSE
#define TJ_FORCESSE2 TJFLAG_FORCESSE2
#define TJ_ALPHAFIRST 64
#define TJ_FORCESSE3 TJFLAG_FORCESSE3
#define TJ_FASTUPSAMPLE TJFLAG_FASTUPSAMPLE
#define TJPAD(width) (((width) + 3) & (~3))
DLLEXPORT unsigned long TJBUFSIZE(int width, int height);
DLLEXPORT int tjCompress(tjhandle handle, unsigned char *srcBuf, int width,
int pitch, int height, int pixelSize,
unsigned char *dstBuf, unsigned long *compressedSize,
int jpegSubsamp, int jpegQual, int flags);
DLLEXPORT int tjDecompress(tjhandle handle, unsigned char *jpegBuf,
unsigned long jpegSize, unsigned char *dstBuf,
int width, int pitch, int height, int pixelSize,
int flags);
DLLEXPORT int tjDecompressHeader(tjhandle handle, unsigned char *jpegBuf,
unsigned long jpegSize, int *width,
int *height);
DLLEXPORT int tjDestroy(tjhandle handle);
DLLEXPORT char *tjGetErrorStr(void);
DLLEXPORT tjhandle tjInitCompress(void);
DLLEXPORT tjhandle tjInitDecompress(void);
/* TurboJPEG 1.1+ */
#define TJ_YUV 512
DLLEXPORT unsigned long TJBUFSIZEYUV(int width, int height, int jpegSubsamp);
DLLEXPORT int tjDecompressHeader2(tjhandle handle, unsigned char *jpegBuf,
unsigned long jpegSize, int *width,
int *height, int *jpegSubsamp);
DLLEXPORT int tjDecompressToYUV(tjhandle handle, unsigned char *jpegBuf,
unsigned long jpegSize, unsigned char *dstBuf,
int flags);
DLLEXPORT int tjEncodeYUV(tjhandle handle, unsigned char *srcBuf, int width,
int pitch, int height, int pixelSize,
unsigned char *dstBuf, int subsamp, int flags);
/* TurboJPEG 1.2+ */
#define TJFLAG_BOTTOMUP 2
#define TJFLAG_FORCEMMX 8
#define TJFLAG_FORCESSE 16
#define TJFLAG_FORCESSE2 32
#define TJFLAG_FORCESSE3 128
#define TJFLAG_FASTUPSAMPLE 256
#define TJFLAG_NOREALLOC 1024
DLLEXPORT unsigned char *tjAlloc(int bytes);
DLLEXPORT unsigned long tjBufSize(int width, int height, int jpegSubsamp);
DLLEXPORT unsigned long tjBufSizeYUV(int width, int height, int subsamp);
DLLEXPORT int tjCompress2(tjhandle handle, const unsigned char *srcBuf,
int width, int pitch, int height, int pixelFormat,
unsigned char **jpegBuf, unsigned long *jpegSize,
int jpegSubsamp, int jpegQual, int flags);
DLLEXPORT int tjDecompress2(tjhandle handle, const unsigned char *jpegBuf,
unsigned long jpegSize, unsigned char *dstBuf,
int width, int pitch, int height, int pixelFormat,
int flags);
DLLEXPORT int tjEncodeYUV2(tjhandle handle, unsigned char *srcBuf, int width,
int pitch, int height, int pixelFormat,
unsigned char *dstBuf, int subsamp, int flags);
DLLEXPORT void tjFree(unsigned char *buffer);
DLLEXPORT tjscalingfactor *tjGetScalingFactors(int *numscalingfactors);
DLLEXPORT tjhandle tjInitTransform(void);
DLLEXPORT int tjTransform(tjhandle handle, const unsigned char *jpegBuf,
unsigned long jpegSize, int n,
unsigned char **dstBufs, unsigned long *dstSizes,
tjtransform *transforms, int flags);
/* TurboJPEG 1.2.1+ */
#define TJFLAG_FASTDCT 2048
#define TJFLAG_ACCURATEDCT 4096
/* TurboJPEG 1.4+ */
DLLEXPORT unsigned long tjBufSizeYUV2(int width, int align, int height,
int subsamp);
DLLEXPORT int tjCompressFromYUV(tjhandle handle, const unsigned char *srcBuf,
int width, int align, int height, int subsamp,
unsigned char **jpegBuf,
unsigned long *jpegSize, int jpegQual,
int flags);
DLLEXPORT int tjCompressFromYUVPlanes(tjhandle handle,
const unsigned char **srcPlanes,
int width, const int *strides,
int height, int subsamp,
unsigned char **jpegBuf,
unsigned long *jpegSize, int jpegQual,
int flags);
DLLEXPORT int tjDecodeYUV(tjhandle handle, const unsigned char *srcBuf,
int align, int subsamp, unsigned char *dstBuf,
int width, int pitch, int height, int pixelFormat,
int flags);
DLLEXPORT int tjDecodeYUVPlanes(tjhandle handle,
const unsigned char **srcPlanes,
const int *strides, int subsamp,
unsigned char *dstBuf, int width, int pitch,
int height, int pixelFormat, int flags);
DLLEXPORT int tjDecompressHeader3(tjhandle handle,
const unsigned char *jpegBuf,
unsigned long jpegSize, int *width,
int *height, int *jpegSubsamp,
int *jpegColorspace);
DLLEXPORT int tjDecompressToYUV2(tjhandle handle, const unsigned char *jpegBuf,
unsigned long jpegSize, unsigned char *dstBuf,
int width, int align, int height, int flags);
DLLEXPORT int tjDecompressToYUVPlanes(tjhandle handle,
const unsigned char *jpegBuf,
unsigned long jpegSize,
unsigned char **dstPlanes, int width,
int *strides, int height, int flags);
DLLEXPORT int tjEncodeYUV3(tjhandle handle, const unsigned char *srcBuf,
int width, int pitch, int height, int pixelFormat,
unsigned char *dstBuf, int align, int subsamp,
int flags);
DLLEXPORT int tjEncodeYUVPlanes(tjhandle handle, const unsigned char *srcBuf,
int width, int pitch, int height,
int pixelFormat, unsigned char **dstPlanes,
int *strides, int subsamp, int flags);
DLLEXPORT int tjPlaneHeight(int componentID, int height, int subsamp);
DLLEXPORT unsigned long tjPlaneSizeYUV(int componentID, int width, int stride,
int height, int subsamp);
DLLEXPORT int tjPlaneWidth(int componentID, int width, int subsamp);
/* TurboJPEG 2.0+ */
#define TJFLAG_STOPONWARNING 8192
#define TJFLAG_PROGRESSIVE 16384
DLLEXPORT int tjGetErrorCode(tjhandle handle);
DLLEXPORT char *tjGetErrorStr2(tjhandle handle);
DLLEXPORT unsigned char *tjLoadImage(const char *filename, int *width,
int align, int *height, int *pixelFormat,
int flags);
DLLEXPORT int tjSaveImage(const char *filename, unsigned char *buffer,
int width, int pitch, int height, int pixelFormat,
int flags);
/* TurboJPEG 2.1+ */
#define TJFLAG_LIMITSCANS 32768
/**
* @}
*/
#ifdef __cplusplus
}
#endif
#endif