/* 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 version only) */ #define TJ_YUV 512 /* If passed to tjCompress(), this causes TurboJPEG/OSS to use the accelerated color conversion routines in libjpeg-turbo 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/OSS 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/OSS. */ 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. 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 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 tjDecompressHeader2(tjhandle j, unsigned char *srcbuf, unsigned long size, int *width, int *height, int *jpegsub) [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 [OUTPUT] jpegsub = 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 *jpegsub); /* Legacy version of the above function */ DLLEXPORT int DLLCALL tjDecompressHeader(tjhandle j, unsigned char *srcbuf, unsigned long size, int *width, int *height); /* int tjDecompress2(tjhandle j, unsigned char *srcbuf, unsigned long size, unsigned char *dstbuf, int pitch, int pixelsize, int scale_num, int scale_denom, 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=ceil(JPEG image height/scale_denom). However, this pointer may also be used to decompress into a specific region of a larger buffer. [INPUT] pitch = bytes per line of the destination image. Normally, this is scaled_width*pixelsize if the bitmap 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=ceil(JPEG image width/scale_denom). 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] pixelsize = size (in bytes) of each pixel in the destination image RGBA/RGBx and BGRA/BGRx: 4, RGB and BGR: 3, Grayscale: 1 [INPUT] scale_num = numerator of scaling factor (currently must be 1) [INPUT] scale_denom = denominator of scaling factor (1, 2, 4, or 8) [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 tjDecompress2(tjhandle j, unsigned char *srcbuf, unsigned long size, unsigned char *dstbuf, int pitch, int pixelsize, int scale_num, int scale_denom, int flags); /* Legacy version of the above function */ 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