DseWiki: MarkusRechberger/libjpeg

Veränderung (zum vorhergehenden Autor) (Änderung, Korrektur, Normalansicht)

Verändert: 1c1,133

Beschreibe hier die neue Seite.

kurzes schnell geschriebenes libjpeg Beispiel (globale variablen sind nicht sehr schön):

[[Code]
#include <stdio.h>
#include <jpeglib.h>
#include <stdlib.h>
#include <unistd.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>

unsigned short int *buffer_16bpp;
void convert_for_16(int w, int x, int y, int r, int g, int b){
buffer_16bpp[y*w+x]=((r>>3)<<11)+((g>>2)<<5)+(b>>3);
}

GC gc_background;
XImage *xim;
int width,height;
Display *display;
Window window;

void createPixmap()
{
Pixmap pixmap;
int depth;
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
int screen;
unsigned long window_mask;
XSetWindowAttributes? window_attributes;

display=XOpenDisplay?((char*)0);
depth = DefaultDepth? (display,DefaultScreen?(display));
screen = DefaultScreen?(display);

XVisualInfo? vinfo;

window_attributes.colormap=XCreateColormap?(display, DefaultRootWindow?(display), vinfo.visual, AllocNone?);

window_attributes.event_mask = 0; //StructureNotifyMask? | ExposureMask?;
// window_attributes.background_pixel=0;
window_attributes.border_pixel=0;

window_mask = CWBackPixel?; // | CWBorderPixel? | CWColormap;// | CWEventMask?;

window=XCreateWindow?(display,DefaultRootWindow?(display), 0, 0, 640,480, 0, depth,InputOutput?, 0, window_mask,&window_attributes); //CopyFromParent?,window_mask ,&window_attributes);
XMapWindow?(display,window);
XFlush(display);

pixmap = XCreatePixmap?(display, window, 640, 480, DefaultDepth?(display,0));

FILE *infile;
char filename[]="loading.jpg";
cinfo.err = jpeg_std_error(&jerr);
jpeg_create_decompress(&cinfo);
if((infile = fopen (filename,"rb")) == NULL){
fprintf(stderr,"ERROR opening file oad.jpg\n");
return;
}
jpeg_stdio_src(&cinfo,infile);
jpeg_read_header(&cinfo,FALSE);
cinfo.do_fancy_upsampling = FALSE;
cinfo.do_block_smoothing = FALSE;

jpeg_start_decompress(&cinfo);

width = cinfo.output_width;
height = cinfo.output_height;
// depth = DefaultDepth?({MP Instance}?.display,{MP Instance}?.window);
depth=16;
if (depth == 16){
// store_data = &convert_for_16;
buffer_16bpp = (unsigned short int *)malloc((width)*(height)*2);
xim = XCreateImage? (display, CopyFromParent?,depth, ZPixmap,0,(char *)buffer_16bpp,width,height,16,width*2);
}

int g;
g=0;

int row_stride;
JSAMPARRAY buffer;
row_stride = cinfo.output_width * cinfo.output_components;
buffer=(*cinfo.mem->alloc_sarray)((j_common_ptr) &cinfo, {JPOOL IMAGE}?,row_stride,1);

int bpix;

bpix = cinfo.output_components;
int a;
int i;

while(cinfo.output_scanline < cinfo.output_height){
jpeg_read_scanlines(&cinfo,buffer,1);
a=0;
for(i=0; i< bpix*cinfo.output_width; i+=bpix){
convert_for_16(width,a,g,buffer[0][i],buffer[0][i+1],buffer[0][i+2]);
a++;
}
g++;
}
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
fclose(infile);

gc_background = XCreateGC?(display,window, 0, NULL);
}

void drawPixmap()
{

XPutImage?(display,window,gc_background,xim,0,0,0,0,width,height);
XFlush(display);

}

int main(){
createPixmap();
drawPixmap();
sleep(10);
return(0);
}
]

Makefile
[[Code]
GCC=gcc
LIBS=-ljpeg -lm -lX11
FLAGS=-L/usr/X11R6?/lib
WALL=-Wall
all:
$(GCC) main.c $(LIBS) $(FLAGS) $(WALL) -o main
]

kurzes schnell geschriebenes libjpeg Beispiel (globale variablen sind nicht sehr schön):

#include <stdio.h> #include <jpeglib.h> #include <stdlib.h> #include <unistd.h> #include <X11/Xlib.h> #include <X11/Xutil.h> unsigned short int *buffer_16bpp; void convert_for_16(int w, int x, int y, int r, int g, int b){ buffer_16bpp[y*w+x]=((r>>3)<<11)+((g>>2)<<5)+(b>>3); } GC gc_background; XImage *xim; int width,height; Display *display; Window window; void createPixmap() { Pixmap pixmap; int depth; struct jpeg_decompress_struct cinfo; struct jpeg_error_mgr jerr; int screen; unsigned long window_mask; XSetWindowAttributes window_attributes; display=XOpenDisplay((char*)0); depth = DefaultDepth (display,DefaultScreen(display)); screen = DefaultScreen(display); XVisualInfo vinfo; window_attributes.colormap=XCreateColormap(display, DefaultRootWindow(display), vinfo.visual, AllocNone); window_attributes.event_mask = 0; //StructureNotifyMask | ExposureMask; // window_attributes.background_pixel=0; window_attributes.border_pixel=0; window_mask = CWBackPixel; // | CWBorderPixel | CWColormap;// | CWEventMask; window=XCreateWindow(display,DefaultRootWindow(display), 0, 0, 640,480, 0, depth,InputOutput, 0, window_mask,&window_attributes); //CopyFromParent,window_mask ,&window_attributes); XMapWindow(display,window); XFlush(display); pixmap = XCreatePixmap(display, window, 640, 480, DefaultDepth(display,0)); FILE *infile; char filename[]="loading.jpg"; cinfo.err = jpeg_std_error(&jerr); jpeg_create_decompress(&cinfo); if((infile = fopen (filename,"rb")) == NULL){ fprintf(stderr,"ERROR opening file oad.jpg\n"); return; } jpeg_stdio_src(&cinfo,infile); jpeg_read_header(&cinfo,FALSE); cinfo.do_fancy_upsampling = FALSE; cinfo.do_block_smoothing = FALSE; jpeg_start_decompress(&cinfo); width = cinfo.output_width; height = cinfo.output_height; // depth = DefaultDepth(MP_Instance.display,MP_Instance.window); depth=16; if (depth == 16){ // store_data = &convert_for_16; buffer_16bpp = (unsigned short int *)malloc((width)*(height)*2); xim = XCreateImage (display, CopyFromParent,depth, ZPixmap,0,(char *)buffer_16bpp,width,height,16,width*2); } int g; g=0; int row_stride; JSAMPARRAY buffer; row_stride = cinfo.output_width * cinfo.output_components; buffer=(*cinfo.mem->alloc_sarray)((j_common_ptr) &cinfo, JPOOL_IMAGE,row_stride,1); int bpix; bpix = cinfo.output_components; int a; int i; while(cinfo.output_scanline < cinfo.output_height){ jpeg_read_scanlines(&cinfo,buffer,1); a=0; for(i=0; i< bpix*cinfo.output_width; i+=bpix){ convert_for_16(width,a,g,buffer[0][i],buffer[0][i+1],buffer[0][i+2]); a++; } g++; } jpeg_finish_decompress(&cinfo); jpeg_destroy_decompress(&cinfo); fclose(infile); gc_background = XCreateGC(display,window, 0, NULL); } void drawPixmap() { XPutImage(display,window,gc_background,xim,0,0,0,0,width,height); XFlush(display); } int main(){ createPixmap(); drawPixmap(); sleep(10); return(0); }

Makefile
GCC=gcc LIBS=-ljpeg -lm -lX11 FLAGS=-L/usr/X11R6/lib WALL=-Wall all: $(GCC) main.c $(LIBS) $(FLAGS) $(WALL) -o main