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mozjpeg/turbojpeg.h
DRC fc881ebb21 TurboJPEG: Implement 4:4:1 chrominance subsampling 
This allows losslessly transposed or rotated 4:1:1 JPEG images to be
losslessly cropped, partially decompressed, or decompressed to planar
YUV images.

Because tj3Transform() allows multiple lossless transformations to be
chained together, all subsampling options need to have a corresponding
transposed subsampling option.  (This is why 4:4:0 was originally
implemented as well.)  Otherwise, the documentation would be technically
incorrect.  It says that images with unknown subsampling types cannot be
losslessly cropped, partially decompressed, or decompressed to planar
YUV images, but it doesn't say anything about images with known
subsampling types whose subsampling type becomes unknown if the image is
rotated or transposed.  This is one of those situations in which it is
easier to implement a feature that works around the problem than to
document the problem.

Closes #659
2023-03-10 10:46:14 -06:00

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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
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __TURBOJPEG_H__
#define __TURBOJPEG_H__
#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
};
/**
* The number of parameters
*/
#define TJ_NUMPARAM
/**
* Parameters
*/
enum TJPARAM {
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
TJPARAM_MAXPIXELS = -1,
#endif
/**
* 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.
* 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`]*
*
* @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_DENSITYUNIT
* is `2`.
*
* @see TJPARAM_DENSITYUNIT
*/
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_DENSITYUNIT
* is `2`.
*
* @see TJPARAM_DENSITYUNIT
*/
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
};
/**
* 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 componentIndex,
int transformIndex, 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. 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
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