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/* Copyright (C)2004 Landmark Graphics Corporation
* Copyright (C)2005, 2006 Sun Microsystems, Inc.
* Copyright (C)2009 D. R. Commander
*
* This library is free software and may be redistributed and/or modified under
* the terms of the wxWindows Library License, Version 3.1 or (at your option)
* any later version. The full license is in the LICENSE.txt file included
* with this distribution.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* wxWindows Library License for more details.
*/
#if (defined(_MSC_VER) || defined(__CYGWIN__) || defined(__MINGW32__)) && defined(_WIN32) && defined(DLLDEFINE)
#define DLLEXPORT __declspec(dllexport)
#else
#define DLLEXPORT
#endif
#define DLLCALL
/* Subsampling */
#define NUMSUBOPT 4
enum {TJ_444=0, TJ_422, TJ_420, TJ_GRAYSCALE};
#define TJ_411 TJ_420 /* for backward compatibility with VirtualGL <= 2.1.x,
TurboVNC <= 0.6, and TurboJPEG/IPP */
/* Flags */
#define TJ_BGR 1
/* The components of each pixel in the source/destination bitmap are stored
in B,G,R order, not R,G,B */
#define TJ_BOTTOMUP 2
/* The source/destination bitmap is stored in bottom-up (Windows, OpenGL)
order, not top-down (X11) order */
#define TJ_FORCEMMX 8
/* Turn off CPU auto-detection and force TurboJPEG to use MMX code
(IPP and 32-bit libjpeg-turbo versions only) */
#define TJ_FORCESSE 16
/* Turn off CPU auto-detection and force TurboJPEG to use SSE code
(32-bit IPP and 32-bit libjpeg-turbo versions only) */
#define TJ_FORCESSE2 32
/* Turn off CPU auto-detection and force TurboJPEG to use SSE2 code
(32-bit IPP and 32-bit libjpeg-turbo versions only) */
#define TJ_ALPHAFIRST 64
/* If the source/destination bitmap is 32 bpp, assume that each pixel is
ARGB/XRGB (or ABGR/XBGR if TJ_BGR is also specified) */
#define TJ_FORCESSE3 128
/* Turn off CPU auto-detection and force TurboJPEG to use SSE3 code
(64-bit IPP version only) */
#define TJ_FASTUPSAMPLE 256
/* Use fast, inaccurate 4:2:2 and 4:2:0 YUV upsampling routines
(libjpeg version only) */
typedef void* tjhandle;
#define TJPAD(p) (((p)+3)&(~3))
#ifndef max
#define max(a,b) ((a)>(b)?(a):(b))
#endif
#ifdef __cplusplus
extern "C" {
#endif
/* API follows */
/*
tjhandle tjInitCompress(void)
Creates a new JPEG compressor instance, allocates memory for the structures,
and returns a handle to the instance. Most applications will only
need to call this once at the beginning of the program or once for each
concurrent thread. Don't try to create a new instance every time you
compress an image, because this will cause performance to suffer.
RETURNS: NULL on error
*/
DLLEXPORT tjhandle DLLCALL tjInitCompress(void);
/*
int tjCompress(tjhandle j,
unsigned char *srcbuf, int width, int pitch, int height, int pixelsize,
unsigned char *dstbuf, unsigned long *size,
int jpegsubsamp, int jpegqual, int flags)
[INPUT] j = instance handle previously returned from a call to
tjInitCompress()
[INPUT] srcbuf = pointer to user-allocated image buffer containing pixels in
RGB(A) or BGR(A) form
[INPUT] width = width (in pixels) of the source image
[INPUT] pitch = bytes per line of the source image (width*pixelsize if the
bitmap is unpadded, else TJPAD(width*pixelsize) if each line of the bitmap
is padded to the nearest 32-bit boundary, such as is the case for Windows
bitmaps. You can also be clever and use this parameter to skip lines, etc.,
as long as the pitch is greater than 0.)
[INPUT] height = height (in pixels) of the source image
[INPUT] pixelsize = size (in bytes) of each pixel in the source image
RGBA and BGRA: 4, RGB and BGR: 3, Grayscale: 1
[INPUT] dstbuf = pointer to user-allocated image buffer which will receive
the JPEG image. Use the macro TJBUFSIZE(width, height) to determine
the appropriate size for this buffer based on the image width and height.
[OUTPUT] size = pointer to unsigned long which receives the size (in bytes)
of the compressed image
[INPUT] jpegsubsamp = Specifies either 4:2:0, 4:2:2, or 4:4:4 subsampling.
When the image is converted from the RGB to YCbCr colorspace as part of the
JPEG compression process, every other Cb and Cr (chrominance) pixel can be
discarded to produce a smaller image with little perceptible loss of
image clarity (the human eye is more sensitive to small changes in
brightness than small changes in color.)
TJ_420: 4:2:0 subsampling. Discards every other Cb, Cr pixel in both
horizontal and vertical directions.
TJ_422: 4:2:2 subsampling. Discards every other Cb, Cr pixel only in
the horizontal direction.
TJ_444: no subsampling.
TJ_GRAYSCALE: Generate grayscale JPEG image
[INPUT] jpegqual = JPEG quality (an integer between 0 and 100 inclusive.)
[INPUT] flags = the bitwise OR of one or more of the flags described in the
"Flags" section above.
RETURNS: 0 on success, -1 on error
*/
DLLEXPORT int DLLCALL tjCompress(tjhandle j,
unsigned char *srcbuf, int width, int pitch, int height, int pixelsize,
unsigned char *dstbuf, unsigned long *size,
int jpegsubsamp, int jpegqual, int flags);
DLLEXPORT unsigned long DLLCALL TJBUFSIZE(int width, int height);
/*
tjhandle tjInitDecompress(void)
Creates a new JPEG decompressor instance, allocates memory for the
structures, and returns a handle to the instance. Most applications will
only need to call this once at the beginning of the program or once for each
concurrent thread. Don't try to create a new instance every time you
decompress an image, because this will cause performance to suffer.
RETURNS: NULL on error
*/
DLLEXPORT tjhandle DLLCALL tjInitDecompress(void);
/*
int tjDecompressHeader(tjhandle j,
unsigned char *srcbuf, unsigned long size,
int *width, int *height)
[INPUT] j = instance handle previously returned from a call to
tjInitDecompress()
[INPUT] srcbuf = pointer to a user-allocated buffer containing the JPEG image
to decompress
[INPUT] size = size of the JPEG image buffer (in bytes)
[OUTPUT] width = width (in pixels) of the JPEG image
[OUTPUT] height = height (in pixels) of the JPEG image
RETURNS: 0 on success, -1 on error
*/
DLLEXPORT int DLLCALL tjDecompressHeader(tjhandle j,
unsigned char *srcbuf, unsigned long size,
int *width, int *height);
/*
int tjDecompress(tjhandle j,
unsigned char *srcbuf, unsigned long size,
unsigned char *dstbuf, int width, int pitch, int height, int pixelsize,
int flags)
[INPUT] j = instance handle previously returned from a call to
tjInitDecompress()
[INPUT] srcbuf = pointer to a user-allocated buffer containing the JPEG image
to decompress
[INPUT] size = size of the JPEG image buffer (in bytes)
[INPUT] dstbuf = pointer to user-allocated image buffer which will receive
the bitmap image. This buffer should normally be pitch*height
bytes in size, although this pointer may also be used to decompress into
a specific region of a larger buffer.
[INPUT] width = width (in pixels) of the destination image
[INPUT] pitch = bytes per line of the destination image (width*pixelsize if the
bitmap is unpadded, else TJPAD(width*pixelsize) if each line of the bitmap
is padded to the nearest 32-bit boundary, such as is the case for Windows
bitmaps. You can also be clever and use this parameter to skip lines, etc.,
as long as the pitch is greater than 0.)
[INPUT] height = height (in pixels) of the destination image
[INPUT] pixelsize = size (in bytes) of each pixel in the destination image
RGBA/RGBx and BGRA/BGRx: 4, RGB and BGR: 3, Grayscale: 1
[INPUT] flags = the bitwise OR of one or more of the flags described in the
"Flags" section above.
RETURNS: 0 on success, -1 on error
*/
DLLEXPORT int DLLCALL tjDecompress(tjhandle j,
unsigned char *srcbuf, unsigned long size,
unsigned char *dstbuf, int width, int pitch, int height, int pixelsize,
int flags);
/*
int tjDestroy(tjhandle h)
Frees structures associated with a compression or decompression instance
[INPUT] h = instance handle (returned from a previous call to
tjInitCompress() or tjInitDecompress()
RETURNS: 0 on success, -1 on error
*/
DLLEXPORT int DLLCALL tjDestroy(tjhandle h);
/*
char *tjGetErrorStr(void)
Returns a descriptive error message explaining why the last command failed
*/
DLLEXPORT char* DLLCALL tjGetErrorStr(void);
#ifdef __cplusplus
}
#endif
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