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mozjpeg/turbojpeg.h
DRC f48f73d4ec xform fuzz: Use src subsamp to calc dst buf size 
Referring to
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=60379
there are some specially-crafted malformed JPEG images that, when
transformed to grayscale, will exceed the worst-case transformed
grayscale JPEG image size.  This is similar in nature to the issue fixed
by 19f9d8f0fd, except that in this case,
the issue occurs regardless of the amount of metadata in the source
image.  Also, the tjTransform() function, the
Java_org_libjpegturbo_turbojpeg_TJTransformer_transform() JNI function,
and TJBench were behaving correctly in this case, because the TurboJPEG
API documentation specifies that the source image's subsampling type
should be used when computing the worst-case transformed JPEG image
size.  (However, only the Java API documentation specified that.  Oops.
The C API documentation now does as well.)  The documented usage
mitigates the issue, and only the transform fuzzer did not adhere to
that.  Thus, this was an issue with the fuzzer itself rather than an
issue with the library.
2023-07-06 09:10:30 -04:00

1785 lines
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/*
* Copyright (C)2009-2015, 2017, 2020-2021, 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__
#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, or 4:4:0; 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.) 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 chrominance subsampling options
*/
#define TJ_NUMSAMP 6
/**
* Chrominance subsampling options.
* When pixels are converted from RGB to YCbCr (see #TJCS_YCbCr) or from CMYK
* to YCCK (see #TJCS_YCCK) as part of the JPEG compression process, some of
* the Cb and Cr (chrominance) components can be discarded or averaged together
* to produce a smaller image with little perceptible loss of image clarity.
* (The human eye is more sensitive to small changes in brightness than to
* small changes in color.) This is called "chrominance subsampling".
*/
enum TJSAMP {
/**
* 4:4:4 chrominance subsampling (no chrominance subsampling). The JPEG or
* YUV image will contain one chrominance component for every pixel in the
* source image.
*/
TJSAMP_444 = 0,
/**
* 4:2:2 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 2x1 block of pixels in the source image.
*/
TJSAMP_422,
/**
* 4:2:0 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 2x2 block of pixels in the source image.
*/
TJSAMP_420,
/**
* Grayscale. The JPEG or YUV image will contain no chrominance components.
*/
TJSAMP_GRAY,
/**
* 4:4:0 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 1x2 block of pixels in the source image.
*
* @note 4:4:0 subsampling is not fully accelerated in libjpeg-turbo.
*/
TJSAMP_440,
/**
* 4:1:1 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 4x1 block of pixels in the source image.
* JPEG images compressed with 4:1:1 subsampling will be almost exactly the
* same size as those compressed with 4:2:0 subsampling, and in the
* aggregate, both subsampling methods produce approximately the same
* perceptual quality. However, 4:1:1 is better able to reproduce sharp
* horizontal features.
*
* @note 4:1:1 subsampling is not fully accelerated in libjpeg-turbo.
*/
TJSAMP_411
};
/**
* MCU block width (in pixels) for a given level of chrominance subsampling.
* MCU block sizes:
* - 8x8 for no subsampling or grayscale
* - 16x8 for 4:2:2
* - 8x16 for 4:4:0
* - 16x16 for 4:2:0
* - 32x8 for 4:1:1
*/
static const int tjMCUWidth[TJ_NUMSAMP] = { 8, 16, 16, 8, 8, 32 };
/**
* MCU block height (in pixels) for a given level of chrominance subsampling.
* MCU block sizes:
* - 8x8 for no subsampling or grayscale
* - 16x8 for 4:2:2
* - 8x16 for 4:4:0
* - 16x16 for 4:2:0
* - 32x8 for 4:1:1
*/
static const int tjMCUHeight[TJ_NUMSAMP] = { 8, 8, 16, 8, 16, 8 };
/**
* The number of pixel formats
*/
#define TJ_NUMPF 12
/**
* Pixel formats
*/
enum TJPF {
/**
* RGB pixel format. The red, green, and blue components in the image are
* stored in 3-byte pixels in the order R, G, B from lowest to highest byte
* address within each pixel.
*/
TJPF_RGB = 0,
/**
* BGR pixel format. The red, green, and blue components in the image are
* stored in 3-byte pixels in the order B, G, R from lowest to highest byte
* address within each pixel.
*/
TJPF_BGR,
/**
* RGBX pixel format. The red, green, and blue components in the image are
* stored in 4-byte pixels in the order R, G, B from lowest to highest byte
* address within each pixel. The X component is ignored when compressing
* and undefined when decompressing.
*/
TJPF_RGBX,
/**
* BGRX pixel format. The red, green, and blue components in the image are
* stored in 4-byte pixels in the order B, G, R from lowest to highest byte
* address within each pixel. The X component is ignored when compressing
* and undefined when decompressing.
*/
TJPF_BGRX,
/**
* XBGR pixel format. The red, green, and blue components in the image are
* stored in 4-byte pixels in the order R, G, B from highest to lowest byte
* address within each pixel. The X component is ignored when compressing
* and undefined when decompressing.
*/
TJPF_XBGR,
/**
* XRGB pixel format. The red, green, and blue components in the image are
* stored in 4-byte pixels in the order B, G, R from highest to lowest byte
* address within each pixel. The X component is ignored when compressing
* and undefined when decompressing.
*/
TJPF_XRGB,
/**
* Grayscale pixel format. Each 1-byte pixel represents a luminance
* (brightness) level from 0 to 255.
*/
TJPF_GRAY,
/**
* RGBA pixel format. This is the same as @ref TJPF_RGBX, except that when
* decompressing, the X component is guaranteed to be 0xFF, which can be
* interpreted as an opaque alpha channel.
*/
TJPF_RGBA,
/**
* BGRA pixel format. This is the same as @ref TJPF_BGRX, except that when
* decompressing, the X component is guaranteed to be 0xFF, which can be
* interpreted as an opaque alpha channel.
*/
TJPF_BGRA,
/**
* ABGR pixel format. This is the same as @ref TJPF_XBGR, except that when
* decompressing, the X component is guaranteed to be 0xFF, which can be
* interpreted as an opaque alpha channel.
*/
TJPF_ABGR,
/**
* ARGB pixel format. This is the same as @ref TJPF_XRGB, except that when
* decompressing, the X component is guaranteed to be 0xFF, which can be
* interpreted as an opaque alpha channel.
*/
TJPF_ARGB,
/**
* CMYK pixel format. Unlike RGB, which is an additive color model used
* primarily for display, CMYK (Cyan/Magenta/Yellow/Key) is a subtractive
* color model used primarily for printing. In the CMYK color model, the
* value of each color component typically corresponds to an amount of cyan,
* magenta, yellow, or black ink that is applied to a white background. In
* order to convert between CMYK and RGB, it is necessary to use a color
* management system (CMS.) A CMS will attempt to map colors within the
* printer's gamut to perceptually similar colors in the display's gamut and
* vice versa, but the mapping is typically not 1:1 or reversible, nor can it
* be defined with a simple formula. Thus, such a conversion is out of scope
* for a codec library. However, the TurboJPEG API allows for compressing
* 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 #tjLoadImage().
*/
TJPF_UNKNOWN = -1
};
/**
* Red offset (in bytes) for a given pixel format. This specifies the number
* of bytes that the red component is offset from the start of the pixel. For
* instance, if a pixel of format 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 bytes) for a given pixel format. This specifies the number
* of bytes that the green component is offset from the start of the pixel.
* For instance, if a pixel of format 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 bytes) for a given pixel format. This specifies the number
* of bytes that the blue component is offset from the start of the pixel. For
* instance, if a pixel of format 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 bytes) for a given pixel format. This specifies the number
* of bytes that the alpha component is offset from the start of the pixel.
* For instance, if a 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 bytes) for a given pixel format
*/
static const int tjPixelSize[TJ_NUMPF] = {
3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 4, 4
};
/**
* The number of JPEG colorspaces
*/
#define TJ_NUMCS 5
/**
* JPEG colorspaces
*/
enum TJCS {
/**
* RGB colorspace. When compressing the JPEG image, the R, G, and B
* components in the source image are reordered into image planes, but no
* colorspace conversion or subsampling is performed. RGB JPEG images can be
* decompressed to packed-pixel images with any of the extended RGB or
* grayscale pixel formats, but they cannot be decompressed to planar YUV
* images.
*/
TJCS_RGB = 0,
/**
* YCbCr colorspace. YCbCr is not an absolute colorspace but rather a
* mathematical transformation of RGB designed solely for storage and
* transmission. YCbCr images must be converted to RGB before they can
* actually be displayed. In the YCbCr colorspace, the Y (luminance)
* component represents the black & white portion of the original image, and
* the Cb and Cr (chrominance) components represent the color portion of the
* original image. Originally, the analog equivalent of this transformation
* allowed the same signal to drive both black & white and color televisions,
* but JPEG images use YCbCr primarily because it allows the color data to be
* optionally subsampled for the purposes of reducing 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 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
};
/**
* Rows in the packed-pixel source/destination image are stored in bottom-up
* (Windows, OpenGL) order rather than in top-down (X11) order.
*/
#define TJFLAG_BOTTOMUP 2
/**
* When decompressing an image that was compressed using chrominance
* subsampling, use the fastest chrominance upsampling algorithm available.
* The default is to use smooth upsampling, which creates a smooth transition
* between neighboring chrominance components in order to reduce upsampling
* artifacts in the decompressed image.
*/
#define TJFLAG_FASTUPSAMPLE 256
/**
* Disable JPEG buffer (re)allocation. If passed to one of the JPEG
* compression or transform functions, this flag will cause those functions to
* generate an error if the JPEG destination buffer is invalid or too small,
* rather than attempt to allocate or reallocate that buffer.
*/
#define TJFLAG_NOREALLOC 1024
/**
* Use the fastest DCT/IDCT algorithm available. The default if this flag is
* not specified is implementation-specific. For example, the implementation
* of the TurboJPEG API in libjpeg-turbo uses the fast algorithm by default
* when compressing, because this has been shown to have only a very slight
* effect on accuracy, but it uses the accurate algorithm when decompressing,
* because this has been shown to have a larger effect.
*/
#define TJFLAG_FASTDCT 2048
/**
* Use the most accurate DCT/IDCT algorithm available. The default if this
* flag is not specified is implementation-specific. For example, the
* implementation of the TurboJPEG API in libjpeg-turbo uses the fast algorithm
* by default when compressing, because this has been shown to have only a very
* slight effect on accuracy, but it uses the accurate algorithm when
* decompressing, because this has been shown to have a larger effect.
*/
#define TJFLAG_ACCURATEDCT 4096
/**
* Immediately discontinue the current compression/decompression/transform
* operation if a warning (non-fatal error) occurs. The default behavior is to
* allow the operation to complete unless a fatal error is encountered.
*/
#define TJFLAG_STOPONWARNING 8192
/**
* Use progressive entropy coding in JPEG images generated by the compression
* and transform functions. Progressive entropy coding will generally improve
* compression relative to baseline entropy coding (the default), but it will
* reduce compression and decompression performance considerably.
*/
#define TJFLAG_PROGRESSIVE 16384
/**
* Limit the number of progressive JPEG scans that the decompression and
* transform functions will process. If a progressive JPEG image contains an
* unreasonably large number of scans, then this flag will cause the
* decompression and transform functions to return an error. 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>.
*/
#define TJFLAG_LIMITSCANS 32768
/**
* 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 = 0,
/**
* The error was fatal and non-recoverable.
*/
TJERR_FATAL
};
/**
* The number of transform operations
*/
#define TJ_NUMXOP 8
/**
* Transform operations for #tjTransform()
*/
enum TJXOP {
/**
* Do not transform the position of the image pixels
*/
TJXOP_NONE = 0,
/**
* Flip (mirror) image horizontally. This transform is imperfect if there
* are any partial MCU blocks on the right edge (see #TJXOPT_PERFECT.)
*/
TJXOP_HFLIP,
/**
* Flip (mirror) image vertically. This transform is imperfect if there are
* any partial MCU blocks on the bottom edge (see #TJXOPT_PERFECT.)
*/
TJXOP_VFLIP,
/**
* Transpose image (flip/mirror along upper left to lower right axis.) This
* transform is always perfect.
*/
TJXOP_TRANSPOSE,
/**
* Transverse transpose image (flip/mirror along upper right to lower left
* axis.) This transform is imperfect if there are any partial MCU blocks in
* the image (see #TJXOPT_PERFECT.)
*/
TJXOP_TRANSVERSE,
/**
* Rotate image clockwise by 90 degrees. This transform is imperfect if
* there are any partial MCU blocks on the bottom edge (see
* #TJXOPT_PERFECT.)
*/
TJXOP_ROT90,
/**
* Rotate image 180 degrees. This transform is imperfect if there are any
* partial MCU blocks in the image (see #TJXOPT_PERFECT.)
*/
TJXOP_ROT180,
/**
* Rotate image counter-clockwise by 90 degrees. This transform is imperfect
* if there are any partial MCU blocks on the right edge (see
* #TJXOPT_PERFECT.)
*/
TJXOP_ROT270
};
/**
* This option will cause #tjTransform() to return an error if the transform is
* not perfect. Lossless transforms operate on MCU blocks, whose size depends
* on the level of chrominance subsampling used (see #tjMCUWidth and
* #tjMCUHeight.) If the image's width or height is not evenly divisible by
* the MCU block size, then there will be partial MCU blocks on the right
* and/or bottom edges. It is not possible to move these partial MCU blocks to
* the top or left of the image, so any transform that would require that is
* "imperfect." If this option is not specified, then any partial MCU blocks
* that cannot be transformed will be left in place, which will create
* odd-looking strips on the right or bottom edge of the image.
*/
#define TJXOPT_PERFECT 1
/**
* This option will cause #tjTransform() to discard any partial MCU blocks that
* cannot be transformed.
*/
#define TJXOPT_TRIM 2
/**
* This option will enable lossless cropping. See #tjTransform() for more
* information.
*/
#define TJXOPT_CROP 4
/**
* This option will discard the color data in the source image and produce a
* grayscale destination image.
*/
#define TJXOPT_GRAY 8
/**
* This option will prevent #tjTransform() from outputting a JPEG image for
* this particular transform. (This can be used in conjunction with a custom
* filter to capture the transformed DCT coefficients without transcoding
* them.)
*/
#define TJXOPT_NOOUTPUT 16
/**
* 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.
*/
#define TJXOPT_PROGRESSIVE 32
/**
* This option will prevent #tjTransform() from copying any extra markers
* (including EXIF and ICC profile data) from the source image to the
* destination image.
*/
#define TJXOPT_COPYNONE 64
/**
* Scaling factor
*/
typedef struct {
/**
* Numerator
*/
int num;
/**
* Denominator
*/
int denom;
} tjscalingfactor;
/**
* Cropping region
*/
typedef struct {
/**
* The left boundary of the cropping region. This must be evenly divisible
* by the MCU block width (see #tjMCUWidth.)
*/
int x;
/**
* The upper boundary of the cropping region. This must be evenly divisible
* by the MCU block height (see #tjMCUHeight.)
*/
int y;
/**
* The width of the cropping region. Setting this to 0 is the equivalent of
* setting it to the width of the source JPEG image - x.
*/
int w;
/**
* The height of the cropping region. Setting this to 0 is the equivalent of
* setting it to the height of the source JPEG image - y.
*/
int h;
} tjregion;
/**
* Lossless transform
*/
typedef struct tjtransform {
/**
* Cropping region
*/
tjregion r;
/**
* One of the @ref TJXOP "transform operations"
*/
int op;
/**
* The bitwise OR of one of more of the @ref TJXOPT_COPYNONE
* "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 #tjTransform().
*
* @param transform a pointer to a #tjtransform structure that specifies the
* parameters and/or cropping region for this transform
*
* @return 0 if the callback was successful, or -1 if an error occurred.
*/
int (*customFilter) (short *coeffs, tjregion arrayRegion,
tjregion planeRegion, int componentID, int transformID,
struct tjtransform *transform);
} tjtransform;
/**
* TurboJPEG instance handle
*/
typedef void *tjhandle;
/**
* Pad the given width to the nearest multiple of 4
*/
#define TJPAD(width) (((width) + 3) & (~3))
/**
* 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)
#ifdef __cplusplus
extern "C" {
#endif
/**
* Create a TurboJPEG compressor instance.
*
* @return a handle to the newly-created instance, or NULL if an error occurred
* (see #tjGetErrorStr2().)
*/
DLLEXPORT tjhandle tjInitCompress(void);
/**
* Compress a packed-pixel RGB, grayscale, or CMYK image into a JPEG image.
*
* @param handle a handle to a TurboJPEG compressor or transformer instance
*
* @param srcBuf pointer to a buffer containing a packed-pixel RGB, grayscale,
* or CMYK source image to be compressed
*
* @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, or
* <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each row of the image
* is padded to the nearest multiple of 4 bytes, as is the case for Windows
* bitmaps. You can also be clever and use this parameter to skip rows, etc.
* Setting this parameter to 0 is the equivalent of setting it to
* <tt>width * #tjPixelSize[pixelFormat]</tt>.
*
* @param height height (in pixels) of the source image
*
* @param pixelFormat pixel format of the source image (see @ref TJPF
* "Pixel formats".)
*
* @param jpegBuf address of a pointer to 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 #tjAlloc() 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
* #tjBufSize(). This should ensure that the buffer never has to be
* re-allocated. (Setting #TJFLAG_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 #TJFLAG_NOREALLOC,
* you should always check `*jpegBuf` upon return from this function, as it may
* have changed.
*
* @param jpegSize pointer to an unsigned long variable that holds the size of
* the JPEG 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.
*
* @param jpegSubsamp the level of chrominance subsampling to be used when
* generating the JPEG image (see @ref TJSAMP
* "Chrominance subsampling options".)
*
* @param jpegQual the image quality of the generated JPEG image (1 = worst,
* 100 = best)
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
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);
/**
* Compress a unified planar YUV image into a JPEG image.
*
* @param handle a handle to a TurboJPEG compressor or transformer instance
*
* @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 #tjBufSizeYUV2() for the given image width, height, row
* alignment, and level of chrominance subsampling. 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 subsamp the level of chrominance subsampling used in the source image
* (see @ref TJSAMP "Chrominance subsampling options".)
*
* @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 #tjAlloc() 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
* #tjBufSize(). This should ensure that the buffer never has to be
* re-allocated. (Setting #TJFLAG_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 #TJFLAG_NOREALLOC,
* you should always check `*jpegBuf` upon return from this function, as it may
* have changed.
*
* @param jpegSize pointer to an unsigned long variable that holds the size of
* the JPEG 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.
*
* @param jpegQual the image quality of the generated JPEG image (1 = worst,
* 100 = best)
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
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);
/**
* Compress a set of Y, U (Cb), and V (Cr) image planes into a JPEG image.
*
* @param handle a handle to a TurboJPEG compressor or transformer instance
*
* @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
* (or just a Y plane, if compressing a grayscale image) that contain a YUV
* 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 #tjPlaneSizeYUV() for the given image width, height, strides,
* and level of chrominance subsampling. Refer to @ref YUVnotes
* "YUV Image Format Notes" for more details.
*
* @param width width (in pixels) of the source image. If the width is not an
* even multiple of the MCU block width (see #tjMCUWidth), then an intermediate
* buffer copy will be performed.
*
* @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 subsamp the level of chrominance subsampling used in the source image
* (see @ref TJSAMP "Chrominance subsampling options".)
*
* @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 #tjAlloc() 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
* #tjBufSize(). This should ensure that the buffer never has to be
* re-allocated. (Setting #TJFLAG_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 #TJFLAG_NOREALLOC,
* you should always check `*jpegBuf` upon return from this function, as it may
* have changed.
*
* @param jpegSize pointer to an unsigned long variable that holds the size of
* the JPEG 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.
*
* @param jpegQual the image quality of the generated JPEG image (1 = worst,
* 100 = best)
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
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);
/**
* 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".)
*
* @return the maximum size of the buffer (in bytes) required to hold the
* image, or -1 if the arguments are out of bounds.
*/
DLLEXPORT unsigned long tjBufSize(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 -1
* if the arguments are out of bounds.
*/
DLLEXPORT unsigned long tjBufSizeYUV2(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 -1 if the arguments are out of bounds.
*/
DLLEXPORT unsigned long tjPlaneSizeYUV(int componentID, int width, int stride,
int height, int subsamp);
/**
* The plane width of a YUV image plane with the given parameters. Refer to
* @ref YUVnotes "YUV Image Format Notes" for a description of plane width.
*
* @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
*
* @param width width (in pixels) of the YUV image
*
* @param subsamp level of chrominance subsampling in the image (see
* @ref TJSAMP "Chrominance subsampling options".)
*
* @return the plane width of a YUV image plane with the given parameters, or
* -1 if the arguments are out of bounds.
*/
DLLEXPORT int tjPlaneWidth(int componentID, int width, int subsamp);
/**
* The plane height of a YUV image plane with the given parameters. Refer to
* @ref YUVnotes "YUV Image Format Notes" for a description of plane height.
*
* @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
*
* @param height height (in pixels) of the YUV image
*
* @param subsamp level of chrominance subsampling in the image (see
* @ref TJSAMP "Chrominance subsampling options".)
*
* @return the plane height of a YUV image plane with the given parameters, or
* -1 if the arguments are out of bounds.
*/
DLLEXPORT int tjPlaneHeight(int componentID, int height, int subsamp);
/**
* Encode a packed-pixel RGB or grayscale image into a 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 a handle to a TurboJPEG compressor or transformer instance
*
* @param srcBuf pointer to a buffer containing a packed-pixel RGB or grayscale
* source image to be encoded
*
* @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, or
* <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each row of the image
* is padded to the nearest multiple of 4 bytes, as is the case for Windows
* bitmaps. You can also be clever and use this parameter to skip rows, etc.
* Setting this parameter to 0 is the equivalent of setting it to
* <tt>width * #tjPixelSize[pixelFormat]</tt>.
*
* @param height height (in pixels) of the source image
*
* @param pixelFormat pixel format of the source image (see @ref TJPF
* "Pixel formats".)
*
* @param dstBuf pointer to a buffer that will receive the unified planar YUV
* image. Use #tjBufSizeYUV2() to determine the appropriate size for this
* buffer based on the image width, height, row alignment, and level of
* chrominance subsampling. The Y, U (Cb), and V (Cr) image planes will be
* stored sequentially in the buffer. (Refer to @ref YUVnotes
* "YUV Image Format Notes".)
*
* @param 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.
*
* @param subsamp the level of chrominance subsampling to be used when
* generating the YUV image (see @ref TJSAMP
* "Chrominance subsampling options".) To generate images suitable for X
* Video, `subsamp` should be set to @ref TJSAMP_420. This produces an image
* compatible with the I420 (AKA "YUV420P") format.
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
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);
/**
* Encode a packed-pixel RGB or grayscale image into separate 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 a handle to a TurboJPEG compressor or transformer instance
*
* @param srcBuf pointer to a buffer containing a packed-pixel RGB or grayscale
* source image to be encoded
*
* @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, or
* <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each row of the image
* is padded to the nearest multiple of 4 bytes, as is the case for Windows
* bitmaps. You can also be clever and use this parameter to skip rows, etc.
* Setting this parameter to 0 is the equivalent of setting it to
* <tt>width * #tjPixelSize[pixelFormat]</tt>.
*
* @param height height (in pixels) of the source image
*
* @param pixelFormat pixel format of the source image (see @ref TJPF
* "Pixel formats".)
*
* @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
* (or just a Y plane, if generating a grayscale image) that will receive the
* encoded image. These planes can be contiguous or non-contiguous in memory.
* Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based
* on the image width, height, strides, and level of chrominance subsampling.
* Refer to @ref YUVnotes "YUV Image Format Notes" for more details.
*
* @param strides an array of integers, each specifying the number of bytes per
* 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.
*
* @param subsamp the level of chrominance subsampling to be used when
* generating the YUV image (see @ref TJSAMP
* "Chrominance subsampling options".) To generate images suitable for X
* Video, `subsamp` should be set to @ref TJSAMP_420. This produces an image
* compatible with the I420 (AKA "YUV420P") format.
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
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);
/**
* Create a TurboJPEG decompressor instance.
*
* @return a handle to the newly-created instance, or NULL if an error occurred
* (see #tjGetErrorStr2().)
*/
DLLEXPORT tjhandle tjInitDecompress(void);
/**
* Retrieve information about a JPEG image without decompressing it, or prime
* the decompressor with quantization and Huffman tables.
*
* @param handle a handle to a TurboJPEG decompressor or transformer instance
*
* @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)
*
* @param width pointer to an integer variable that will receive the width (in
* pixels) of the JPEG image. If `jpegBuf` points to a tables-only datastream,
* then `width` is ignored.
*
* @param height pointer to an integer variable that will receive the height
* (in pixels) of the JPEG image. If `jpegBuf` points to a tables-only
* datastream, then `height` is ignored.
*
* @param jpegSubsamp pointer to an integer variable that will receive the
* level of chrominance subsampling used when the JPEG image was compressed
* (see @ref TJSAMP "Chrominance subsampling options".) If `jpegBuf` points to
* a tables-only datastream, then `jpegSubsamp` is ignored.
*
* @param jpegColorspace pointer to an integer variable that will receive one
* of the JPEG colorspace constants, indicating the colorspace of the JPEG
* image (see @ref TJCS "JPEG colorspaces".) If `jpegBuf` points to a
* tables-only datastream, then `jpegColorspace` is ignored.
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
DLLEXPORT int tjDecompressHeader3(tjhandle handle,
const unsigned char *jpegBuf,
unsigned long jpegSize, int *width,
int *height, int *jpegSubsamp,
int *jpegColorspace);
/**
* Returns a list of fractional scaling factors that the JPEG decompressor
* 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 #tjGetErrorStr2().)
*/
DLLEXPORT tjscalingfactor *tjGetScalingFactors(int *numScalingFactors);
/**
* Decompress a JPEG image into a packed-pixel RGB, grayscale, or CMYK image.
*
* @param handle a handle to a TurboJPEG decompressor or transformer instance
*
* @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 * scaledHeight`
* bytes in size, where `scaledHeight` can be determined by calling #TJSCALED()
* with the JPEG image height and one of the scaling factors returned by
* #tjGetScalingFactors(). The `dstBuf` pointer may also be used to decompress
* into a specific region of a larger buffer.
*
* @param width desired width (in pixels) of the destination image. If this is
* different than the width of the JPEG image being decompressed, then
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
* possible image that will fit within the desired width. If `width` is set to
* 0, then only the height will be considered when determining the scaled image
* size.
*
* @param pitch bytes per row in the destination image. Normally this should
* be set to <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt>, if the
* destination image should be unpadded, or
* <tt>#TJPAD(scaledWidth * #tjPixelSize[pixelFormat])</tt> if each row of the
* destination image should be padded to the nearest multiple of 4 bytes, as is
* the case for Windows bitmaps. (NOTE: `scaledWidth` can be determined by
* calling #TJSCALED() with the JPEG image width and one of the scaling factors
* returned by #tjGetScalingFactors().) You can also be clever and use the
* pitch parameter to skip rows, etc. Setting this parameter to 0 is the
* equivalent of setting it to
* <tt>scaledWidth * #tjPixelSize[pixelFormat]</tt>.
*
* @param height desired height (in pixels) of the destination image. If this
* is different than the height of the JPEG image being decompressed, then
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
* possible image that will fit within the desired height. If `height` is set
* to 0, then only the width will be considered when determining the scaled
* image size.
*
* @param pixelFormat pixel format of the destination image (see @ref
* TJPF "Pixel formats".)
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
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);
/**
* Decompress a JPEG image into a 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.
*
* @param handle a handle to a TurboJPEG decompressor or transformer instance
*
* @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 #tjBufSizeYUV2() to determine the appropriate size
* for this buffer based on the scaled image width, scaled image height, row
* alignment, and level of chrominance subsampling. The Y, U (Cb), and V (Cr)
* image planes will be stored sequentially in the buffer. (Refer to
* @ref YUVnotes "YUV Image Format Notes".)
*
* @param width desired width (in pixels) of the YUV image. If this is
* different than the width of the JPEG image being decompressed, then
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
* possible image that will fit within the desired width. If `width` is set to
* 0, then only the height will be considered when determining the scaled image
* size. If the scaled width is not an even multiple of the MCU block width
* (see #tjMCUWidth), then an intermediate buffer copy will be performed.
*
* @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.
*
* @param height desired height (in pixels) of the YUV image. If this is
* different than the height of the JPEG image being decompressed, then
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
* possible image that will fit within the desired height. If `height` is set
* to 0, then only the width will be considered when determining the scaled
* image size. If the scaled height is not an even multiple of the MCU block
* height (see #tjMCUHeight), then an intermediate buffer copy will be
* performed.
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
DLLEXPORT int tjDecompressToYUV2(tjhandle handle, const unsigned char *jpegBuf,
unsigned long jpegSize, unsigned char *dstBuf,
int width, int align, int height, int flags);
/**
* Decompress a JPEG image into separate Y, U (Cb), and V (Cr) image
* planes. This function performs JPEG decompression but leaves out the color
* conversion step, so a planar YUV image is generated instead of a
* packed-pixel image.
*
* @param handle a handle to a TurboJPEG decompressor or transformer instance
*
* @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 #tjPlaneSizeYUV() to determine the appropriate size for each
* plane based on the scaled image width, scaled image height, strides, and
* level of chrominance subsampling. Refer to @ref YUVnotes
* "YUV Image Format Notes" for more details.
*
* @param width desired width (in pixels) of the YUV image. If this is
* different than the width of the JPEG image being decompressed, then
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
* possible image that will fit within the desired width. If `width` is set to
* 0, then only the height will be considered when determining the scaled image
* size. If the scaled width is not an even multiple of the MCU block width
* (see #tjMCUWidth), then an intermediate buffer copy will be performed.
*
* @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.
*
* @param height desired height (in pixels) of the YUV image. If this is
* different than the height of the JPEG image being decompressed, then
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
* possible image that will fit within the desired height. If `height` is set
* to 0, then only the width will be considered when determining the scaled
* image size. If the scaled height is not an even multiple of the MCU block
* height (see #tjMCUHeight), then an intermediate buffer copy will be
* performed.
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
DLLEXPORT int tjDecompressToYUVPlanes(tjhandle handle,
const unsigned char *jpegBuf,
unsigned long jpegSize,
unsigned char **dstPlanes, int width,
int *strides, int height, int flags);
/**
* Decode a unified planar YUV image into a 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 a handle to a TurboJPEG decompressor or transformer instance
*
* @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 #tjBufSizeYUV2() for the given image width, height, row
* alignment, and level of chrominance subsampling. The Y, U (Cb), and V (Cr)
* image planes should be stored sequentially in the source buffer. (Refer to
* @ref YUVnotes "YUV Image Format Notes".)
*
* @param 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 subsamp the level of chrominance subsampling used in the YUV source
* image (see @ref TJSAMP "Chrominance subsampling options".)
*
* @param dstBuf pointer to a buffer that will receive the packed-pixel decoded
* image. This buffer should normally be `pitch * height` bytes in size, but
* the `dstBuf` pointer can also be used to decode into a specific region of a
* larger buffer.
*
* @param width width (in pixels) of the source and destination images
*
* @param pitch bytes per row in the destination image. Normally this should
* be set to <tt>width * #tjPixelSize[pixelFormat]</tt>, if the destination
* image should be unpadded, or
* <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each row of the
* destination image should be padded to the nearest multiple of 4 bytes, as is
* the case for Windows bitmaps. You can also be clever and use the pitch
* parameter to skip rows, etc. Setting this parameter to 0 is the equivalent
* of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.
*
* @param height height (in pixels) of the source and destination images
*
* @param pixelFormat pixel format of the destination image (see @ref TJPF
* "Pixel formats".)
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
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);
/**
* Decode a set of Y, U (Cb), and V (Cr) image planes into a 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 a handle to a TurboJPEG decompressor or transformer instance
*
* @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
* (or just a Y plane, if decoding a grayscale image) that contain a YUV image
* to be decoded. These planes can be contiguous or non-contiguous in memory.
* The size of each plane should match the value returned by #tjPlaneSizeYUV()
* for the given image width, height, strides, and level of chrominance
* subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" for more
* details.
*
* @param strides an array of integers, each specifying the number of bytes per
* 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 subsamp the level of chrominance subsampling used in the YUV source
* image (see @ref TJSAMP "Chrominance subsampling options".)
*
* @param dstBuf pointer to a buffer that will receive the packed-pixel decoded
* image. This buffer should normally be `pitch * height` bytes in size, but
* the `dstBuf` pointer can also be used to decode into a specific region of a
* larger buffer.
*
* @param width width (in pixels) of the source and destination images
*
* @param pitch bytes per row in the destination image. Normally this should
* be set to <tt>width * #tjPixelSize[pixelFormat]</tt>, if the destination
* image should be unpadded, or
* <tt>#TJPAD(width * #tjPixelSize[pixelFormat])</tt> if each row of the
* destination image should be padded to the nearest multiple of 4 bytes, as is
* the case for Windows bitmaps. You can also be clever and use the pitch
* parameter to skip rows, etc. Setting this parameter to 0 is the equivalent
* of setting it to <tt>width * #tjPixelSize[pixelFormat]</tt>.
*
* @param height height (in pixels) of the source and destination images
*
* @param pixelFormat pixel format of the destination image (see @ref TJPF
* "Pixel formats".)
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
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);
/**
* Create a new TurboJPEG transformer instance.
*
* @return a handle to the newly-created instance, or NULL if an error
* occurred (see #tjGetErrorStr2().)
*/
DLLEXPORT tjhandle tjInitTransform(void);
/**
* Losslessly transform a JPEG image into another JPEG image. Lossless
* transforms work by moving the raw DCT coefficients from one JPEG image
* structure to another without altering the values of the coefficients. While
* this is typically faster than decompressing the image, transforming it, and
* re-compressing it, lossless transforms are not free. Each lossless
* transform requires reading and performing Huffman decoding on all of the
* coefficients in the source image, regardless of the size of the destination
* image. Thus, this function provides a means of generating multiple
* transformed images from the same source or applying multiple transformations
* simultaneously, in order to eliminate the need to read the source
* coefficients multiple times.
*
* @param handle a handle to a TurboJPEG transformer instance
*
* @param jpegBuf pointer to a 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
* #tjAlloc() 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
* #tjBufSize() 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
* #TJFLAG_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 #TJFLAG_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 #TJFLAG_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 unsigned long 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.
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2()
* and #tjGetErrorCode().)
*/
DLLEXPORT int tjTransform(tjhandle handle, const unsigned char *jpegBuf,
unsigned long jpegSize, int n,
unsigned char **dstBufs, unsigned long *dstSizes,
tjtransform *transforms, int flags);
/**
* Destroy a TurboJPEG compressor, decompressor, or transformer instance.
*
* @param handle a handle to a TurboJPEG compressor, decompressor or
* transformer instance
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2().)
*/
DLLEXPORT int tjDestroy(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 #TJFLAG_NOREALLOC.)
*
* @param bytes the number of bytes to allocate
*
* @return a pointer to a newly-allocated buffer with the specified number of
* bytes.
*
* @sa tjFree()
*/
DLLEXPORT unsigned char *tjAlloc(int bytes);
/**
* Load a packed-pixel image from disk into memory.
*
* @param filename name of a file containing a packed-pixel image in Windows
* BMP or PBMPLUS (PPM/PGM) format
*
* @param width pointer to an integer variable that will receive the width (in
* pixels) of the packed-pixel image
*
* @param align row alignment 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 bytes (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
* #tjLoadImage() 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.
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
* "flags".
*
* @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 #tjGetErrorStr2().) This
* buffer should be freed using #tjFree().
*/
DLLEXPORT unsigned char *tjLoadImage(const char *filename, int *width,
int align, int *height, int *pixelFormat,
int flags);
/**
* Save a packed-pixel image from memory to disk.
*
* @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.
*
* @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 bytes 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.)
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_BOTTOMUP
* "flags".
*
* @return 0 if successful, or -1 if an error occurred (see #tjGetErrorStr2().)
*/
DLLEXPORT int tjSaveImage(const char *filename, unsigned char *buffer,
int width, int pitch, int height, int pixelFormat,
int flags);
/**
* 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 #tjAlloc().
*
* @param buffer address of the buffer to free. If the address is NULL, then
* this function has no effect.
*
* @sa tjAlloc()
*/
DLLEXPORT void tjFree(unsigned char *buffer);
/**
* Returns a descriptive error message explaining why the last command failed.
*
* @param handle a handle to a TurboJPEG compressor, decompressor, or
* transformer 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 *tjGetErrorStr2(tjhandle handle);
/**
* Returns a code indicating the severity of the last error. See
* @ref TJERR "Error codes".
*
* @param handle a handle to a TurboJPEG compressor, decompressor or
* transformer instance
*
* @return a code indicating the severity of the last error. See
* @ref TJERR "Error codes".
*/
DLLEXPORT int tjGetErrorCode(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
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 char *tjGetErrorStr(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_FORCEMMX 8
#define TJFLAG_FORCESSE 16
#define TJFLAG_FORCESSE2 32
#define TJFLAG_FORCESSE3 128
DLLEXPORT unsigned long tjBufSizeYUV(int width, int height, int subsamp);
DLLEXPORT int tjEncodeYUV2(tjhandle handle, unsigned char *srcBuf, int width,
int pitch, int height, int pixelFormat,
unsigned char *dstBuf, int subsamp, int flags);
/**
* @}
*/
#ifdef __cplusplus
}
#endif
#endif
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