/*
* Copyright (C)2009-2015, 2017, 2020-2021 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
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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*/
#ifndef __TURBOJPEG_H__
#define __TURBOJPEG_H__
#if defined(_WIN32) && defined(DLLDEFINE)
#define DLLEXPORT __declspec(dllexport)
#else
#define DLLEXPORT
#endif
#define DLLCALL
/**
* @addtogroup TurboJPEG
* TurboJPEG API. This API provides an interface for generating, decoding, and
* transforming planar YUV and JPEG images in memory.
*
* @anchor YUVnotes
* YUV Image Format Notes
* ----------------------
* Technically, the JPEG format uses the YCbCr colorspace (which is technically
* not a colorspace but a color transform), but per the convention of the
* digital video community, the TurboJPEG API uses "YUV" to refer to an image
* format consisting of Y, Cb, and Cr image planes.
*
* Each plane is simply a 2D array of bytes, each byte representing the value
* of one of the components (Y, Cb, or Cr) at a particular location in the
* image. The width and height of each plane are determined by the image
* width, height, and level of chrominance subsampling. The luminance plane
* width is the image width padded to the nearest multiple of the horizontal
* subsampling factor (2 in the case of 4:2:0 and 4:2:2, 4 in the case of
* 4:1:1, 1 in the case of 4:4:4 or grayscale.) Similarly, the luminance plane
* height is the image height padded to the nearest multiple of the vertical
* subsampling factor (2 in the case of 4:2:0 or 4:4:0, 1 in the case of 4:4:4
* or grayscale.) This is irrespective of any additional padding that may be
* specified as an argument to the various YUV functions. The chrominance
* plane width is equal to the luminance plane width divided by the horizontal
* subsampling factor, and the chrominance plane height is equal to the
* luminance plane height divided by the vertical subsampling factor.
*
* For example, if the source image is 35 x 35 pixels and 4:2:2 subsampling is
* used, then the luminance plane would be 36 x 35 bytes, and each of the
* chrominance planes would be 18 x 35 bytes. If you specify a line padding of
* 4 bytes on top of this, then the luminance plane would be 36 x 35 bytes, and
* each of the chrominance planes would be 20 x 35 bytes.
*
* @{
*/
/**
* The number of chrominance subsampling options
*/
#define TJ_NUMSAMP 6
/**
* Chrominance subsampling options.
* When pixels are converted from RGB to YCbCr (see #TJCS_YCbCr) or from CMYK
* to YCCK (see #TJCS_YCCK) as part of the JPEG compression process, some of
* the Cb and Cr (chrominance) components can be discarded or averaged together
* to produce a smaller image with little perceptible loss of image clarity
* (the human eye is more sensitive to small changes in brightness than to
* small changes in color.) This is called "chrominance subsampling".
*/
enum TJSAMP {
/**
* 4:4:4 chrominance subsampling (no chrominance subsampling). The JPEG or
* YUV image will contain one chrominance component for every pixel in the
* source image.
*/
TJSAMP_444 = 0,
/**
* 4:2:2 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 2x1 block of pixels in the source image.
*/
TJSAMP_422,
/**
* 4:2:0 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 2x2 block of pixels in the source image.
*/
TJSAMP_420,
/**
* Grayscale. The JPEG or YUV image will contain no chrominance components.
*/
TJSAMP_GRAY,
/**
* 4:4:0 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 1x2 block of pixels in the source image.
*
* @note 4:4:0 subsampling is not fully accelerated in libjpeg-turbo.
*/
TJSAMP_440,
/**
* 4:1:1 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 4x1 block of pixels in the source image.
* JPEG images compressed with 4:1:1 subsampling will be almost exactly the
* same size as those compressed with 4:2:0 subsampling, and in the
* aggregate, both subsampling methods produce approximately the same
* perceptual quality. However, 4:1:1 is better able to reproduce sharp
* horizontal features.
*
* @note 4:1:1 subsampling is not fully accelerated in libjpeg-turbo.
*/
TJSAMP_411
};
/**
* MCU block width (in pixels) for a given level of chrominance subsampling.
* MCU block sizes:
* - 8x8 for no subsampling or grayscale
* - 16x8 for 4:2:2
* - 8x16 for 4:4:0
* - 16x16 for 4:2:0
* - 32x8 for 4:1:1
*/
static const int tjMCUWidth[TJ_NUMSAMP] = { 8, 16, 16, 8, 8, 32 };
/**
* MCU block height (in pixels) for a given level of chrominance subsampling.
* MCU block sizes:
* - 8x8 for no subsampling or grayscale
* - 16x8 for 4:2:2
* - 8x16 for 4:4:0
* - 16x16 for 4:2:0
* - 32x8 for 4:1:1
*/
static const int tjMCUHeight[TJ_NUMSAMP] = { 8, 8, 16, 8, 16, 8 };
/**
* The number of pixel formats
*/
#define TJ_NUMPF 12
/**
* Pixel formats
*/
enum TJPF {
/**
* RGB pixel format. The red, green, and blue components in the image are
* stored in 3-byte pixels in the order R, G, B from lowest to highest byte
* address within each pixel.
*/
TJPF_RGB = 0,
/**
* BGR pixel format. The red, green, and blue components in the image are
* stored in 3-byte pixels in the order B, G, R from lowest to highest byte
* address within each pixel.
*/
TJPF_BGR,
/**
* RGBX pixel format. The red, green, and blue components in the image are
* stored in 4-byte pixels in the order R, G, B from lowest to highest byte
* address within each pixel. The X component is ignored when compressing
* and undefined when decompressing.
*/
TJPF_RGBX,
/**
* BGRX pixel format. The red, green, and blue components in the image are
* stored in 4-byte pixels in the order B, G, R from lowest to highest byte
* address within each pixel. The X component is ignored when compressing
* and undefined when decompressing.
*/
TJPF_BGRX,
/**
* XBGR pixel format. The red, green, and blue components in the image are
* stored in 4-byte pixels in the order R, G, B from highest to lowest byte
* address within each pixel. The X component is ignored when compressing
* and undefined when decompressing.
*/
TJPF_XBGR,
/**
* XRGB pixel format. The red, green, and blue components in the image are
* stored in 4-byte pixels in the order B, G, R from highest to lowest byte
* address within each pixel. The X component is ignored when compressing
* and undefined when decompressing.
*/
TJPF_XRGB,
/**
* Grayscale pixel format. Each 1-byte pixel represents a luminance
* (brightness) level from 0 to 255.
*/
TJPF_GRAY,
/**
* RGBA pixel format. This is the same as @ref TJPF_RGBX, except that when
* decompressing, the X component is guaranteed to be 0xFF, which can be
* interpreted as an opaque alpha channel.
*/
TJPF_RGBA,
/**
* BGRA pixel format. This is the same as @ref TJPF_BGRX, except that when
* decompressing, the X component is guaranteed to be 0xFF, which can be
* interpreted as an opaque alpha channel.
*/
TJPF_BGRA,
/**
* ABGR pixel format. This is the same as @ref TJPF_XBGR, except that when
* decompressing, the X component is guaranteed to be 0xFF, which can be
* interpreted as an opaque alpha channel.
*/
TJPF_ABGR,
/**
* ARGB pixel format. This is the same as @ref TJPF_XRGB, except that when
* decompressing, the X component is guaranteed to be 0xFF, which can be
* interpreted as an opaque alpha channel.
*/
TJPF_ARGB,
/**
* CMYK pixel format. Unlike RGB, which is an additive color model used
* primarily for display, CMYK (Cyan/Magenta/Yellow/Key) is a subtractive
* color model used primarily for printing. In the CMYK color model, the
* value of each color component typically corresponds to an amount of cyan,
* magenta, yellow, or black ink that is applied to a white background. In
* order to convert between CMYK and RGB, it is necessary to use a color
* management system (CMS.) A CMS will attempt to map colors within the
* printer's gamut to perceptually similar colors in the display's gamut and
* vice versa, but the mapping is typically not 1:1 or reversible, nor can it
* be defined with a simple formula. Thus, such a conversion is out of scope
* for a codec library. However, the TurboJPEG API allows for compressing
* CMYK pixels into a YCCK JPEG image (see #TJCS_YCCK) and decompressing YCCK
* JPEG images into CMYK pixels.
*/
TJPF_CMYK,
/**
* 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 TJ_BGRX is stored in char pixel[],
* then the red component will be pixel[tjRedOffset[TJ_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 TJ_BGRX is stored in
* char pixel[], then the green component will be
* pixel[tjGreenOffset[TJ_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 TJ_BGRX is stored in char pixel[],
* then the blue component will be pixel[tjBlueOffset[TJ_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 TJ_BGRA is stored in
* char pixel[], then the alpha component will be
* pixel[tjAlphaOffset[TJ_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 any of the extended RGB pixel formats or grayscale, but
* they cannot be decompressed to YUV images.
*/
TJCS_RGB = 0,
/**
* YCbCr colorspace. YCbCr is not an absolute colorspace but rather a
* mathematical transformation of RGB designed solely for storage and
* transmission. YCbCr images must be converted to RGB before they can
* actually be displayed. In the YCbCr colorspace, the Y (luminance)
* component represents the black & white portion of the original image, and
* the Cb and Cr (chrominance) components represent the color portion of the
* original image. Originally, the analog equivalent of this transformation
* allowed the same signal to drive both black & white and color televisions,
* but JPEG images use YCbCr primarily because it allows the color data to be
* optionally subsampled for the purposes of reducing bandwidth or disk
* space. YCbCr is the most common JPEG colorspace, and YCbCr JPEG images
* can be compressed from and decompressed to any of the extended RGB pixel
* formats or grayscale, or they can be decompressed to YUV planar images.
*/
TJCS_YCbCr,
/**
* Grayscale colorspace. The JPEG image retains only the luminance data (Y
* component), and any color data from the source image is discarded.
* Grayscale JPEG images can be compressed from and decompressed to any of
* the extended RGB pixel formats or grayscale, or they can be decompressed
* to YUV planar images.
*/
TJCS_GRAY,
/**
* CMYK colorspace. When compressing the JPEG image, the C, M, Y, and K
* components in the source image are reordered into image planes, but no
* colorspace conversion or subsampling is performed. CMYK JPEG images can
* only be decompressed to CMYK pixels.
*/
TJCS_CMYK,
/**
* YCCK colorspace. YCCK (AKA "YCbCrK") is not an absolute colorspace but
* rather a mathematical transformation of CMYK designed solely for storage
* and transmission. It is to CMYK as YCbCr is to RGB. CMYK pixels can be
* reversibly transformed into YCCK, and as with YCbCr, the chrominance
* components in the YCCK pixels can be subsampled without incurring major
* perceptual loss. YCCK JPEG images can only be compressed from and
* decompressed to CMYK pixels.
*/
TJCS_YCCK
};
/**
* The uncompressed source/destination image is stored in bottom-up (Windows,
* OpenGL) order, not top-down (X11) order.
*/
#define TJFLAG_BOTTOMUP 2
/**
* When decompressing an image that was compressed using chrominance
* subsampling, use the fastest chrominance upsampling algorithm available in
* the underlying codec. The default is to use smooth upsampling, which
* creates a smooth transition between neighboring chrominance components in
* order to reduce upsampling artifacts in the decompressed image.
*/
#define TJFLAG_FASTUPSAMPLE 256
/**
* Disable buffer (re)allocation. If passed to one of the JPEG compression or
* transform functions, this flag will cause those functions to generate an
* error if the JPEG image buffer is invalid or too small rather than
* attempting to allocate or reallocate that buffer. This reproduces the
* behavior of earlier versions of TurboJPEG.
*/
#define TJFLAG_NOREALLOC 1024
/**
* Use the fastest DCT/IDCT algorithm available in the underlying codec. The
* default if this flag is not specified is implementation-specific. For
* example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast
* algorithm by default when compressing, because this has been shown to have
* only a very slight effect on accuracy, but it uses the accurate algorithm
* when decompressing, because this has been shown to have a larger effect.
*/
#define TJFLAG_FASTDCT 2048
/**
* Use the most accurate DCT/IDCT algorithm available in the underlying codec.
* The default if this flag is not specified is implementation-specific. For
* example, the implementation of TurboJPEG for libjpeg[-turbo] uses the fast
* algorithm by default when compressing, because this has been shown to have
* only a very slight effect on accuracy, but it uses the accurate algorithm
* when decompressing, because this has been shown to have a larger effect.
*/
#define TJFLAG_ACCURATEDCT 4096
/**
* Immediately discontinue the current compression/decompression/transform
* operation if the underlying codec throws a warning (non-fatal error). 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
* this report.
*/
#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 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 input image and produce
* a grayscale output image.
*/
#define TJXOPT_GRAY 8
/**
* This option will prevent #tjTransform() from outputting a JPEG image for
* this particular transform (this can be used in conjunction with a custom
* filter to capture the transformed DCT coefficients without transcoding
* them.)
*/
#define TJXOPT_NOOUTPUT 16
/**
* This option will enable progressive entropy coding in the output image
* generated by this particular transform. Progressive entropy coding will
* generally improve compression relative to baseline entropy coding (the
* default), but it will reduce compression and 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 output
* 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_CROP "transform options"
*/
int options;
/**
* Arbitrary data that can be accessed within the body of the callback
* function
*/
void *data;
/**
* A callback function that can be used to modify the DCT coefficients
* after they are losslessly transformed but before they are transcoded to a
* new JPEG image. This allows for custom filters or other transformations
* to be applied in the frequency domain.
*
* @param coeffs pointer to an array of transformed DCT coefficients. (NOTE:
* this pointer is not guaranteed to be valid once the callback returns, so
* applications wishing to hand off the DCT coefficients to another function
* or library should make a copy of them within the body of the callback.)
*
* @param arrayRegion #tjregion structure containing the width and height of
* the array pointed to by 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 componentIndex,
int transformIndex, struct tjtransform *transform);
} tjtransform;
/**
* TurboJPEG instance handle
*/
typedef void *tjhandle;
/**
* Pad the given width to the nearest 32-bit boundary
*/
#define TJPAD(width) (((width) + 3) & (~3))
/**
* Compute the scaled value of 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 an RGB, grayscale, or CMYK image into a JPEG image.
*
* @param handle a handle to a TurboJPEG compressor or transformer instance
*
* @param srcBuf pointer to an image buffer containing RGB, grayscale, or
* CMYK pixels to be compressed
*
* @param width width (in pixels) of the source image
*
* @param pitch bytes per line in the source image. Normally, this should be
* width * #tjPixelSize[pixelFormat] if the image is unpadded, or
* #TJPAD(width * #tjPixelSize[pixelFormat]) if each line of the image
* is padded to the nearest 32-bit boundary, as is the case for Windows
* bitmaps. You can also be clever and use this parameter to skip lines, etc.
* Setting this parameter to 0 is the equivalent of setting it to
* width * #tjPixelSize[pixelFormat].
*
* @param height height (in pixels) of the source image
*
* @param pixelFormat pixel format of the source image (see @ref TJPF
* "Pixel formats".)
*
* @param jpegBuf address of a pointer to an image buffer that will receive the
* JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer
* to accommodate the size of the JPEG image. Thus, you can choose to:
* -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
* let TurboJPEG grow the buffer as needed,
* -# set *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, *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 image 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 image 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 YUV planar image into a JPEG image.
*
* @param handle a handle to a TurboJPEG compressor or transformer instance
*
* @param srcBuf pointer to an image buffer containing a YUV planar image to be
* compressed. The size of this buffer should match the value returned by
* #tjBufSizeYUV2() for the given image width, height, padding, and level of
* chrominance subsampling. The Y, U (Cb), and V (Cr) image planes should be
* stored sequentially in the source buffer (refer to @ref YUVnotes
* "YUV Image Format Notes".)
*
* @param width width (in pixels) of the source image. If the width is not an
* even multiple of the MCU block width (see #tjMCUWidth), then an intermediate
* buffer copy will be performed within TurboJPEG.
*
* @param pad the line padding used in the source image. For instance, if each
* line in each plane of the YUV image is padded to the nearest multiple of 4
* bytes, then pad should be set to 4.
*
* @param height height (in pixels) of the source image. If the height is not
* an even multiple of the MCU block height (see #tjMCUHeight), then an
* intermediate buffer copy will be performed within TurboJPEG.
*
* @param subsamp the level of chrominance subsampling used in the source
* image (see @ref TJSAMP "Chrominance subsampling options".)
*
* @param jpegBuf address of a pointer to an image buffer that will receive the
* JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to
* accommodate the size of the JPEG image. Thus, you can choose to:
* -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
* let TurboJPEG grow the buffer as needed,
* -# set *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, *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 image 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 image 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 pad, int height, int subsamp,
unsigned char **jpegBuf,
unsigned long *jpegSize, int jpegQual,
int flags);
/**
* Compress a set of Y, U (Cb), and V (Cr) image planes into a JPEG image.
*
* @param handle a handle to a TurboJPEG compressor or transformer instance
*
* @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
* (or just a Y plane, if compressing a grayscale image) that contain a YUV
* image to be compressed. These planes can be contiguous or non-contiguous in
* memory. The size of each plane should match the value returned by
* #tjPlaneSizeYUV() for the given image width, height, strides, and level of
* chrominance subsampling. Refer to @ref YUVnotes "YUV Image Format Notes"
* for more details.
*
* @param width width (in pixels) of the source image. If the width is not an
* even multiple of the MCU block width (see #tjMCUWidth), then an intermediate
* buffer copy will be performed within TurboJPEG.
*
* @param strides an array of integers, each specifying the number of bytes per
* line in the corresponding plane of the YUV source image. Setting the stride
* for any plane to 0 is the same as setting it to the plane width (see
* @ref YUVnotes "YUV Image Format Notes".) If 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 line
* padding in each plane or to create a JPEG image from a subregion of a larger
* YUV planar image.
*
* @param height height (in pixels) of the source image. If the height is not
* an even multiple of the MCU block height (see #tjMCUHeight), then an
* intermediate buffer copy will be performed within TurboJPEG.
*
* @param subsamp the level of chrominance subsampling used in the source
* image (see @ref TJSAMP "Chrominance subsampling options".)
*
* @param jpegBuf address of a pointer to an image buffer that will receive the
* JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to
* accommodate the size of the JPEG image. Thus, you can choose to:
* -# pre-allocate the JPEG buffer with an arbitrary size using #tjAlloc() and
* let TurboJPEG grow the buffer as needed,
* -# set *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, *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 image 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 image 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, and it is thus possible
* for a very high-quality JPEG image with very high-frequency content to
* expand rather than compress when converted to the JPEG format. Such images
* represent a very rare corner case, but since there is no way to predict the
* size of a JPEG image prior to compression, the corner case has to be
* handled.
*
* @param width width (in pixels) of the image
*
* @param height height (in pixels) of the image
*
* @param jpegSubsamp the level of chrominance subsampling to be used when
* generating the JPEG image (see @ref TJSAMP
* "Chrominance subsampling options".)
*
* @return the maximum size of the buffer (in bytes) required to hold the
* image, or -1 if the arguments are out of bounds.
*/
DLLEXPORT unsigned long tjBufSize(int width, int height, int jpegSubsamp);
/**
* The size of the buffer (in bytes) required to hold a YUV planar image with
* the given parameters.
*
* @param width width (in pixels) of the image
*
* @param pad the width of each line in each plane of the image is padded to
* the nearest multiple of this number of bytes (must be a power of 2.)
*
* @param height height (in pixels) of the image
*
* @param subsamp level of chrominance subsampling in the image (see
* @ref TJSAMP "Chrominance subsampling options".)
*
* @return the size of the buffer (in bytes) required to hold the image, or
* -1 if the arguments are out of bounds.
*/
DLLEXPORT unsigned long tjBufSizeYUV2(int width, int pad, int height,
int subsamp);
/**
* The size of the buffer (in bytes) required to hold a YUV image plane with
* the given parameters.
*
* @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
*
* @param width width (in pixels) of the YUV image. NOTE: this is the width of
* the whole image, not the plane width.
*
* @param stride bytes per line in the image plane. Setting this to 0 is the
* equivalent of setting it to the plane width.
*
* @param height height (in pixels) of the YUV image. NOTE: this is the height
* of the whole image, not the plane height.
*
* @param subsamp level of chrominance subsampling in the image (see
* @ref TJSAMP "Chrominance subsampling options".)
*
* @return the size of the buffer (in bytes) required to hold the YUV image
* plane, or -1 if the arguments are out of bounds.
*/
DLLEXPORT unsigned long tjPlaneSizeYUV(int componentID, int width, int stride,
int height, int subsamp);
/**
* The plane width of a YUV image plane with the given parameters. Refer to
* @ref YUVnotes "YUV Image Format Notes" for a description of plane width.
*
* @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
*
* @param width width (in pixels) of the YUV image
*
* @param subsamp level of chrominance subsampling in the image (see
* @ref TJSAMP "Chrominance subsampling options".)
*
* @return the plane width of a YUV image plane with the given parameters, or
* -1 if the arguments are out of bounds.
*/
DLLEXPORT int tjPlaneWidth(int componentID, int width, int subsamp);
/**
* The plane height of a YUV image plane with the given parameters. Refer to
* @ref YUVnotes "YUV Image Format Notes" for a description of plane height.
*
* @param componentID ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
*
* @param height height (in pixels) of the YUV image
*
* @param subsamp level of chrominance subsampling in the image (see
* @ref TJSAMP "Chrominance subsampling options".)
*
* @return the plane height of a YUV image plane with the given parameters, or
* -1 if the arguments are out of bounds.
*/
DLLEXPORT int tjPlaneHeight(int componentID, int height, int subsamp);
/**
* Encode an RGB or grayscale image into a YUV planar image. This function
* uses the accelerated color conversion routines in the underlying
* codec but does not execute any of the other steps in the JPEG compression
* process.
*
* @param handle a handle to a TurboJPEG compressor or transformer instance
*
* @param srcBuf pointer to an image buffer containing RGB or grayscale pixels
* to be encoded
*
* @param width width (in pixels) of the source image
*
* @param pitch bytes per line in the source image. Normally, this should be
* width * #tjPixelSize[pixelFormat] if the image is unpadded, or
* #TJPAD(width * #tjPixelSize[pixelFormat]) if each line of the image
* is padded to the nearest 32-bit boundary, as is the case for Windows
* bitmaps. You can also be clever and use this parameter to skip lines, etc.
* Setting this parameter to 0 is the equivalent of setting it to
* width * #tjPixelSize[pixelFormat].
*
* @param height height (in pixels) of the source image
*
* @param pixelFormat pixel format of the source image (see @ref TJPF
* "Pixel formats".)
*
* @param dstBuf pointer to an image buffer that will receive the YUV image.
* Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based
* on the image width, height, padding, and level of chrominance subsampling.
* The Y, U (Cb), and V (Cr) image planes will be stored sequentially in the
* buffer (refer to @ref YUVnotes "YUV Image Format Notes".)
*
* @param pad the width of each line in each plane of the YUV image will be
* padded to the nearest multiple of this number of bytes (must be a power of
* 2.) To generate images suitable for X Video, pad 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 pad, int subsamp,
int flags);
/**
* Encode an RGB or grayscale image into separate Y, U (Cb), and V (Cr) image
* planes. This function uses the accelerated color conversion routines in the
* underlying codec but does not execute any of the other steps in the JPEG
* compression process.
*
* @param handle a handle to a TurboJPEG compressor or transformer instance
*
* @param srcBuf pointer to an image buffer containing RGB or grayscale pixels
* to be encoded
*
* @param width width (in pixels) of the source image
*
* @param pitch bytes per line in the source image. Normally, this should be
* width * #tjPixelSize[pixelFormat] if the image is unpadded, or
* #TJPAD(width * #tjPixelSize[pixelFormat]) if each line of the image
* is padded to the nearest 32-bit boundary, as is the case for Windows
* bitmaps. You can also be clever and use this parameter to skip lines, etc.
* Setting this parameter to 0 is the equivalent of setting it to
* width * #tjPixelSize[pixelFormat].
*
* @param height height (in pixels) of the source image
*
* @param pixelFormat pixel format of the source image (see @ref TJPF
* "Pixel formats".)
*
* @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
* (or just a Y plane, if generating a grayscale image) that will receive the
* encoded image. These planes can be contiguous or non-contiguous in memory.
* Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based
* on the image width, height, strides, and level of chrominance subsampling.
* Refer to @ref YUVnotes "YUV Image Format Notes" for more details.
*
* @param strides an array of integers, each specifying the number of bytes per
* line in the corresponding plane of the output image. Setting the stride for
* any plane to 0 is the same as setting it to the plane width (see
* @ref YUVnotes "YUV Image Format Notes".) If 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 line
* padding to each plane or to encode an RGB or grayscale image into a
* subregion of a larger YUV planar image.
*
* @param subsamp the level of chrominance subsampling to be used when
* generating the YUV image (see @ref TJSAMP
* "Chrominance subsampling options".) To generate images suitable for X
* Video, 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.
*
* @param handle a handle to a TurboJPEG decompressor or transformer instance
*
* @param jpegBuf pointer to a buffer containing a JPEG image
*
* @param jpegSize size of the JPEG image (in bytes)
*
* @param width pointer to an integer variable that will receive the width (in
* pixels) of the JPEG image
*
* @param height pointer to an integer variable that will receive the height
* (in pixels) of the JPEG image
*
* @param jpegSubsamp pointer to an integer variable that will receive the
* level of chrominance subsampling used when the JPEG image was compressed
* (see @ref TJSAMP "Chrominance subsampling options".)
*
* @param jpegColorspace pointer to an integer variable that will receive one
* of the JPEG colorspace constants, indicating the colorspace of the JPEG
* image (see @ref TJCS "JPEG colorspaces".)
*
* @return 0 if successful, or -1 if an error occurred (see #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 in
* this implementation of TurboJPEG supports.
*
* @param numscalingfactors pointer to an integer variable that will receive
* the number of elements in the list
*
* @return a pointer to a list of fractional scaling factors, or NULL if an
* error is encountered (see #tjGetErrorStr2().)
*/
DLLEXPORT tjscalingfactor *tjGetScalingFactors(int *numscalingfactors);
/**
* Decompress a JPEG image to an RGB, grayscale, or CMYK image.
*
* @param handle a handle to a TurboJPEG decompressor or transformer instance
*
* @param jpegBuf pointer to a buffer containing the JPEG image to decompress
*
* @param jpegSize size of the JPEG image (in bytes)
*
* @param dstBuf pointer to an image buffer that will receive the decompressed
* image. This buffer should normally be 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 line in the destination image. Normally, this is
* scaledWidth * #tjPixelSize[pixelFormat] if the decompressed image
* is unpadded, else #TJPAD(scaledWidth * #tjPixelSize[pixelFormat])
* if each line of the decompressed image is padded to the nearest 32-bit
* boundary, 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 lines, etc. Setting this
* parameter to 0 is the equivalent of setting it to
* scaledWidth * #tjPixelSize[pixelFormat].
*
* @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 to a YUV planar image. This function performs JPEG
* decompression but leaves out the color conversion step, so a planar YUV
* image is generated instead of an RGB image.
*
* @param handle a handle to a TurboJPEG decompressor or transformer instance
*
* @param jpegBuf pointer to a buffer containing the JPEG image to decompress
*
* @param jpegSize size of the JPEG image (in bytes)
*
* @param dstBuf pointer to an image buffer that will receive the YUV image.
* Use #tjBufSizeYUV2() to determine the appropriate size for this buffer based
* on the image width, height, padding, and level of subsampling. The Y,
* U (Cb), and V (Cr) image planes will be stored sequentially in the buffer
* (refer to @ref YUVnotes "YUV Image Format Notes".)
*
* @param width desired width (in pixels) of the YUV image. If this is
* different than the width of the JPEG image being decompressed, then
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
* possible image that will fit within the desired width. If 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 within TurboJPEG.
*
* @param pad the width of each line in each plane of the YUV image will be
* padded to the nearest multiple of this number of bytes (must be a power of
* 2.) To generate images suitable for X Video, pad 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 within TurboJPEG.
*
* @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 pad, int height, int flags);
/**
* Decompress a JPEG image into separate Y, U (Cb), and V (Cr) image
* planes. This function performs JPEG decompression but leaves out the color
* conversion step, so a planar YUV image is generated instead of an RGB image.
*
* @param handle a handle to a TurboJPEG decompressor or transformer instance
*
* @param jpegBuf pointer to a buffer containing the JPEG image to decompress
*
* @param jpegSize size of the JPEG image (in bytes)
*
* @param dstPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
* (or just a Y plane, if decompressing a grayscale image) that will receive
* the YUV image. These planes can be contiguous or non-contiguous in memory.
* Use #tjPlaneSizeYUV() to determine the appropriate size for each plane based
* on the scaled image width, scaled image height, strides, and level of
* chrominance subsampling. Refer to @ref YUVnotes "YUV Image Format Notes"
* for more details.
*
* @param width desired width (in pixels) of the YUV image. If this is
* different than the width of the JPEG image being decompressed, then
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
* possible image that will fit within the desired width. If 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 within TurboJPEG.
*
* @param strides an array of integers, each specifying the number of bytes per
* line in the corresponding plane of the output image. Setting the stride for
* any plane to 0 is the same as setting it to the scaled plane width (see
* @ref YUVnotes "YUV Image Format Notes".) If 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
* line padding to each plane or to decompress the JPEG image into a subregion
* of a larger YUV planar image.
*
* @param height desired height (in pixels) of the YUV image. If this is
* different than the height of the JPEG image being decompressed, then
* TurboJPEG will use scaling in the JPEG decompressor to generate the largest
* possible image that will fit within the desired height. If 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 within TurboJPEG.
*
* @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 YUV planar image into an RGB or grayscale image. This function
* uses the accelerated color conversion routines in the underlying
* codec but does not execute any of the other steps in the JPEG decompression
* process.
*
* @param handle a handle to a TurboJPEG decompressor or transformer instance
*
* @param srcBuf pointer to an image buffer containing a YUV planar image to be
* decoded. The size of this buffer should match the value returned by
* #tjBufSizeYUV2() for the given image width, height, padding, and level of
* chrominance subsampling. The Y, U (Cb), and V (Cr) image planes should be
* stored sequentially in the source buffer (refer to @ref YUVnotes
* "YUV Image Format Notes".)
*
* @param pad Use this parameter to specify that the width of each line in each
* plane of the YUV source image is padded to the nearest multiple of this
* number of bytes (must be a power of 2.)
*
* @param subsamp the level of chrominance subsampling used in the YUV source
* image (see @ref TJSAMP "Chrominance subsampling options".)
*
* @param dstBuf pointer to an image buffer that will receive the decoded
* image. This buffer should normally be 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 line in the destination image. Normally, this should
* be width * #tjPixelSize[pixelFormat] if the destination image is
* unpadded, or #TJPAD(width * #tjPixelSize[pixelFormat]) if each line
* of the destination image should be padded to the nearest 32-bit boundary, as
* is the case for Windows bitmaps. You can also be clever and use the pitch
* parameter to skip lines, etc. Setting this parameter to 0 is the equivalent
* of setting it to width * #tjPixelSize[pixelFormat].
*
* @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 pad, int subsamp, unsigned char *dstBuf,
int width, int pitch, int height, int pixelFormat,
int flags);
/**
* Decode a set of Y, U (Cb), and V (Cr) image planes into an RGB or grayscale
* image. This function uses the accelerated color conversion routines in the
* underlying codec but does not execute any of the other steps in the JPEG
* decompression process.
*
* @param handle a handle to a TurboJPEG decompressor or transformer instance
*
* @param srcPlanes an array of pointers to Y, U (Cb), and V (Cr) image planes
* (or just a Y plane, if decoding a grayscale image) that contain a YUV image
* to be decoded. These planes can be contiguous or non-contiguous in memory.
* The size of each plane should match the value returned by #tjPlaneSizeYUV()
* for the given image width, height, strides, and level of chrominance
* subsampling. Refer to @ref YUVnotes "YUV Image Format Notes" for more
* details.
*
* @param strides an array of integers, each specifying the number of bytes per
* line in the corresponding plane of the YUV source image. Setting the stride
* for any plane to 0 is the same as setting it to the plane width (see
* @ref YUVnotes "YUV Image Format Notes".) If 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 line
* padding in each plane or to decode a subregion of a larger YUV planar image.
*
* @param subsamp the level of chrominance subsampling used in the YUV source
* image (see @ref TJSAMP "Chrominance subsampling options".)
*
* @param dstBuf pointer to an image buffer that will receive the decoded
* image. This buffer should normally be 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 line in the destination image. Normally, this should
* be width * #tjPixelSize[pixelFormat] if the destination image is
* unpadded, or #TJPAD(width * #tjPixelSize[pixelFormat]) if each line
* of the destination image should be padded to the nearest 32-bit boundary, as
* is the case for Windows bitmaps. You can also be clever and use the pitch
* parameter to skip lines, etc. Setting this parameter to 0 is the equivalent
* of setting it to width * #tjPixelSize[pixelFormat].
*
* @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 buffer containing the JPEG source image to
* transform
*
* @param jpegSize size of the JPEG source image (in bytes)
*
* @param n the number of transformed JPEG images to generate
*
* @param dstBufs pointer to an array of n image buffers. 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
* 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 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. 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 output image
* will be larger than the worst-case size, and #TJFLAG_NOREALLOC cannot be
* used in those cases.
* .
* If you choose option 1, 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 JPEG image (in bytes.)
*
* @param transforms pointer to an array of n #tjtransform structures, each of
* which specifies the transform parameters and/or cropping region for the
* corresponding transformed output image.
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_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 an image 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 an uncompressed image from disk into memory.
*
* @param filename name of a file containing an uncompressed 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 uncompressed image
*
* @param align row alignment of the image buffer to be returned (must be a
* power of 2.) For instance, setting this parameter to 4 will cause all rows
* in the image buffer to be padded to the nearest 32-bit boundary, and setting
* this parameter to 1 will cause all rows in the image buffer to be unpadded.
*
* @param height pointer to an integer variable that will receive the height
* (in pixels) of the uncompressed image
*
* @param pixelFormat pointer to an integer variable that specifies or will
* receive the pixel format of the uncompressed image buffer. The behavior of
* #tjLoadImage() will vary depending on the value of *pixelFormat
* passed to the function:
* - @ref TJPF_UNKNOWN : The uncompressed image buffer returned by the function
* will use the most optimal pixel format for the file type, and
* *pixelFormat will contain the ID of this pixel format upon
* successful return from the function.
* - @ref TJPF_GRAY : Only PGM files and 8-bit 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 uncompressed image 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 uncompressed
* 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 an uncompressed image from memory to disk.
*
* @param filename name of a file to which to save the uncompressed image.
* The image will be stored in Windows BMP or PBMPLUS (PPM/PGM) format,
* depending on the file extension.
*
* @param buffer pointer to an image buffer containing RGB, grayscale, or
* CMYK pixels to be saved
*
* @param width width (in pixels) of the uncompressed image
*
* @param pitch bytes per line in the image buffer. Setting this parameter to
* 0 is the equivalent of setting it to
* width * #tjPixelSize[pixelFormat].
*
* @param height height (in pixels) of the uncompressed image
*
* @param pixelFormat pixel format of the image buffer (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 (indexed color) BMP format. Otherwise,
* the image will be stored in PPM or 24-bit 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 (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 an image buffer previously allocated by TurboJPEG. You should always
* use this function to free JPEG destination buffer(s) that were automatically
* (re)allocated by 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);
/* Deprecated functions and macros */
#define TJFLAG_FORCEMMX 8
#define TJFLAG_FORCESSE 16
#define TJFLAG_FORCESSE2 32
#define TJFLAG_FORCESSE3 128
/* Backward compatibility functions and macros (nothing to see here) */
#define NUMSUBOPT TJ_NUMSAMP
#define TJ_444 TJSAMP_444
#define TJ_422 TJSAMP_422
#define TJ_420 TJSAMP_420
#define TJ_411 TJSAMP_420
#define TJ_GRAYSCALE TJSAMP_GRAY
#define TJ_BGR 1
#define TJ_BOTTOMUP TJFLAG_BOTTOMUP
#define TJ_FORCEMMX TJFLAG_FORCEMMX
#define TJ_FORCESSE TJFLAG_FORCESSE
#define TJ_FORCESSE2 TJFLAG_FORCESSE2
#define TJ_ALPHAFIRST 64
#define TJ_FORCESSE3 TJFLAG_FORCESSE3
#define TJ_FASTUPSAMPLE TJFLAG_FASTUPSAMPLE
#define TJ_YUV 512
DLLEXPORT unsigned long TJBUFSIZE(int width, int height);
DLLEXPORT unsigned long TJBUFSIZEYUV(int width, int height, int jpegSubsamp);
DLLEXPORT unsigned long tjBufSizeYUV(int width, int height, int subsamp);
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 tjEncodeYUV(tjhandle handle, unsigned char *srcBuf, int width,
int pitch, int height, int pixelSize,
unsigned char *dstBuf, int subsamp, 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 int tjDecompressHeader(tjhandle handle, unsigned char *jpegBuf,
unsigned long jpegSize, int *width,
int *height);
DLLEXPORT int tjDecompressHeader2(tjhandle handle, unsigned char *jpegBuf,
unsigned long jpegSize, int *width,
int *height, int *jpegSubsamp);
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 tjDecompressToYUV(tjhandle handle, unsigned char *jpegBuf,
unsigned long jpegSize, unsigned char *dstBuf,
int flags);
DLLEXPORT char *tjGetErrorStr(void);
/**
* @}
*/
#ifdef __cplusplus
}
#endif
#endif