зеркало из https://github.com/mozilla/mozjpeg.git
318 строки
13 KiB
C
318 строки
13 KiB
C
/* Copyright (C)2004 Landmark Graphics Corporation
|
|
* Copyright (C)2005, 2006 Sun Microsystems, Inc.
|
|
* Copyright (C)2009-2011 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 and libjpeg-turbo versions only) */
|
|
#define TJ_YUV 512
|
|
/* If passed to tjCompress(), this causes TurboJPEG to use the accelerated
|
|
color conversion routines in the underlying codec to produce a planar
|
|
YUV image that is suitable for X Video. Specifically, if the chrominance
|
|
components are subsampled along the horizontal dimension, then the width
|
|
of the luminance plane is padded to 2 in the output image (same goes for
|
|
the height of the luminance plane, if the chrominance components are
|
|
subsampled along the vertical dimension.) Also, each line of each plane
|
|
in the output image is padded to 4 bytes. Although this will work with
|
|
any subsampling option, it is really only useful in combination with
|
|
TJ_420, which produces an image compatible with the I420 (AKA "YUV420P")
|
|
format.
|
|
|
|
If passed to tjDecompress(), this tells TurboJPEG to perform JPEG
|
|
decompression but to leave out the color conversion step, so a planar YUV
|
|
image is generated instead of an RGB image. The padding of the planes in
|
|
this image is the same as in the above case. Note that, if the width or
|
|
height of the output image is not a multiple of 8 (or a multiple of 16
|
|
along any dimension in which chrominance subsampling is used), then an
|
|
intermediate buffer copy will be performed within TurboJPEG.
|
|
*/
|
|
|
|
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 RGB or
|
|
grayscale pixels to be compressed
|
|
[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. Setting this parameter to 0 is the equivalent of setting it to
|
|
width*pixelsize.
|
|
[INPUT] height = height (in pixels) of the source image
|
|
[INPUT] pixelsize = size (in bytes) of each pixel in the source image
|
|
RGBX/BGRX/XRGB/XBGR: 4, RGB/BGR: 3, Grayscale: 1
|
|
[INPUT] dstbuf = pointer to user-allocated image buffer which will receive
|
|
the JPEG image. Use the TJBUFSIZE(width, height) function 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);
|
|
|
|
|
|
/*
|
|
unsigned long TJBUFSIZE(int width, int height)
|
|
|
|
Convenience function which returns the maximum size of the buffer required to
|
|
hold a JPEG image with the given width and height
|
|
|
|
RETURNS: -1 if arguments are out of bounds
|
|
*/
|
|
DLLEXPORT unsigned long DLLCALL TJBUFSIZE(int width, int height);
|
|
|
|
|
|
/*
|
|
unsigned long TJBUFSIZEYUV(int width, int height, int subsamp)
|
|
|
|
Convenience function which returns the size of the buffer required to
|
|
hold a YUV planar image with the given width, height, and level of
|
|
chrominance subsampling
|
|
|
|
RETURNS: -1 if arguments are out of bounds
|
|
*/
|
|
DLLEXPORT unsigned long DLLCALL TJBUFSIZEYUV(int width, int height,
|
|
int subsamp);
|
|
|
|
|
|
/*
|
|
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 tjDecompressHeader2(tjhandle j,
|
|
unsigned char *srcbuf, unsigned long size,
|
|
int *width, int *height, int *jpegsubsamp)
|
|
|
|
[INPUT] j = instance handle previously returned from a call to
|
|
tjInitDecompress()
|
|
[INPUT] srcbuf = pointer to a user-allocated buffer containing a JPEG image
|
|
[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
|
|
[OUTPUT] jpegsubsamp = type of chrominance subsampling used when compressing
|
|
the JPEG image
|
|
|
|
RETURNS: 0 on success, -1 on error
|
|
*/
|
|
DLLEXPORT int DLLCALL tjDecompressHeader2(tjhandle j,
|
|
unsigned char *srcbuf, unsigned long size,
|
|
int *width, int *height, int *jpegsubsamp);
|
|
|
|
/*
|
|
Legacy version of the above function
|
|
*/
|
|
DLLEXPORT int DLLCALL tjDecompressHeader(tjhandle j,
|
|
unsigned char *srcbuf, unsigned long size,
|
|
int *width, int *height);
|
|
|
|
|
|
/*
|
|
int tjScaledSize(int input_width, int input_height,
|
|
int *output_width, int *output_height)
|
|
|
|
[INPUT] input_width = width (in pixels) of the JPEG image
|
|
[INPUT] input_height = height (in pixels) of the JPEG image
|
|
[INPUT/OUTPUT] output_width, output_height = Before calling this function,
|
|
*output_width and *output_height should be set to the desired dimensions
|
|
of the output image. Upon returning from this function, they will be set
|
|
to the dimensions of the largest scaled down image that TurboJPEG can
|
|
produce without exceeding the desired dimensions. If either *output_width
|
|
or *output_height is set to 0, then the corresponding dimension will not
|
|
be considered when determining the scaled image size.
|
|
|
|
RETURNS: 0 on success, -1 if arguments are out of bounds
|
|
*/
|
|
DLLEXPORT int DLLCALL tjScaledSize(int input_width, int input_height,
|
|
int *output_width, int *output_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*scaled_height
|
|
bytes in size, where scaled_height is determined by calling
|
|
tjScaledSize() with the height of the desired output image. This pointer
|
|
may also be used to decompress into a specific region of a
|
|
larger buffer.
|
|
[INPUT] width = desired width (in pixels) of the destination image. If this
|
|
is smaller 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.
|
|
[INPUT] pitch = bytes per line of the destination image. Normally, this is
|
|
scaled_width*pixelsize if the bitmap image is unpadded, else
|
|
TJPAD(scaled_width*pixelsize) if each line of the bitmap is padded to the
|
|
nearest 32-bit boundary, such as is the case for Windows bitmaps.
|
|
(NOTE: scaled_width can be determined by calling tjScaledSize().) 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 scaled_width*pixelsize.
|
|
[INPUT] height = desired height (in pixels) of the destination image. If
|
|
this is smaller 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.
|
|
[INPUT] pixelsize = size (in bytes) of each pixel in the destination image
|
|
RGBX/BGRX/XRGB/XBGR: 4, RGB/BGR: 3, Grayscale: 1
|
|
[INPUT] flags = the bitwise OR of one or more of the flags described in the
|
|
"Flags" section above.
|
|
|
|
NOTE: The width, pitch, height, and pixelsize parameters are ignored if
|
|
decompressing to a YUV planar image.
|
|
|
|
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
|