This is yuvsplittoppm.c in view mode; [Download] [Up]
/* yuvsplittoppm.c - construct a portable pixmap from 3 raw files:
** - basename.Y : The Luminance chunk at the size of the Image
** - basename.U : The Chrominance chunk U at 1/4
** - basename.V : The Chrominance chunk V at 1/4
** The subsampled U and V values are made by arithmetic mean.
**
** If ccir601 is defined, the produced YUV triples have been scaled again
** to fit into the smaller range of values for this standard.
**
** by Marcel Wijkstra <wijkstra@fwi.uva.nl>
**
** Based on ppmtoyuvsplit.c
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation. This software is provided "as is" without express or
** implied warranty.
*/
#include "ppm.h"
/* x must be signed for the following to work correctly */
#define limit(x) (((x>0xffffff)?0xff0000:((x<=0xffff)?0:x&0xff0000))>>16)
int
main(argc, argv)
char **argv;
{
FILE *ifp,*vf,*uf,*yf;
pixel *pixelrow1,*pixelrow2;
register pixel *pP1,*pP2;
int rows, cols, format, row;
register int col;
pixval maxval;
char *usage="<basename> <width> <height> [-ccir601]";
long int y,u,v,y0,y1,y2,y3,u0,u1,u2,u3,v0,v1,v2,v3;
unsigned char *y1buf,*y2buf,*ubuf,*vbuf;
char ufname[256],vfname[256],yfname[256];
/* Whether to create YUV in JFIF(JPEG) or CCIR.601(MPEG) scale */
int ccir601=0;
ppm_init(&argc, argv);
if ((argc>5) || (argc<4)) pm_usage(usage);
if (argc==5)
if (!strncmp(argv[4],"-c",2))
ccir601 = 1;
else
pm_usage(usage);
strcpy(ufname,argv[1]);
strcpy(vfname,argv[1]);
strcpy(yfname,argv[1]);
strcat(ufname,".U");
strcat(vfname,".V");
strcat(yfname,".Y");
uf = fopen(ufname,"rb");
vf = fopen(vfname,"rb");
yf = fopen(yfname,"rb");
if(!(uf && vf && yf)) {
perror("error opening input files");
exit(0);
}
cols = atoi(argv[2]);
rows = atoi(argv[3]);
if (cols <= 0 || rows <= 0)
pm_usage(usage);
ppm_writeppminit(stdout, cols, rows, (pixval) 255, 0);
if(cols & 1) fprintf(stderr,
"%s: Warning: odd columns count, exceed ignored\n",
argv[0]);
if(rows & 1) fprintf(stderr,
"%s: Warning: odd rows count, exceed ignored\n",
argv[0]);
pixelrow1 = ((pixel*) pm_allocrow( cols, sizeof(pixel) ));
pixelrow2 = ((pixel*) pm_allocrow( cols, sizeof(pixel) ));
y1buf = (unsigned char *) pm_allocrow( cols, 1 );
y2buf = (unsigned char *) pm_allocrow( cols, 1 );
ubuf = (unsigned char *) pm_allocrow( cols, 1 );
vbuf = (unsigned char *) pm_allocrow( cols, 1 );
for (row = 0; row < (rows & ~1); row += 2) {
unsigned char *y1ptr,*y2ptr,*uptr,*vptr;
fread(y1buf, (cols & ~1), 1, yf);
fread(y2buf, (cols & ~1), 1, yf);
fread(ubuf, cols/2, 1, uf);
fread(vbuf, cols/2, 1, vf);
y1ptr = y1buf; y2ptr = y2buf; vptr = vbuf; uptr = ubuf;
pP1 = pixelrow1; pP2 = pixelrow2;
for (col = 0 ; col < (cols & ~1); col += 2) {
long int r0,g0,b0,r1,g1,b1,r2,g2,b2,r3,g3,b3;
y0 = (long int) *y1ptr++;
y1 = (long int) *y1ptr++;
y2 = (long int) *y2ptr++;
y3 = (long int) *y2ptr++;
u = (long int) ((*uptr++) - 128);
v = (long int) ((*vptr++) - 128);
if (ccir601) {
y0 = ((y0-16)*255)/219;
y1 = ((y1-16)*255)/219;
y2 = ((y2-16)*255)/219;
y3 = ((y3-16)*255)/219;
u = (u*255)/224 ;
v = (v*255)/224 ;
}
/* mean the chroma for subsampling */
u0=u1=u2=u3=u;
v0=v1=v2=v3=v;
/* The inverse of the JFIF RGB to YUV Matrix for $00010000 = 1.0
[Y] [65496 0 91880][R]
[U] = [65533 -22580 -46799[G]
[V] [65537 116128 -8][B]
*/
r0 = 65536 * y0 + 91880 * v0;
g0 = 65536 * y0 - 22580 * u0 - 46799 * v0;
b0 = 65536 * y0 + 116128 * u0 ;
r1 = 65536 * y1 + 91880 * v1;
g1 = 65536 * y1 - 22580 * u1 - 46799 * v1;
b1 = 65536 * y1 + 116128 * u1 ;
r2 = 65536 * y2 + 91880 * v2;
g2 = 65536 * y2 - 22580 * u2 - 46799 * v2;
b2 = 65536 * y2 + 116128 * u2 ;
r3 = 65536 * y3 + 91880 * v3;
g3 = 65536 * y3 - 22580 * u3 - 46799 * v3;
b3 = 65536 * y3 + 116128 * u3 ;
r0 = limit(r0);
r1 = limit(r1);
r2 = limit(r2);
r3 = limit(r3);
g0 = limit(g0);
g1 = limit(g1);
g2 = limit(g2);
g3 = limit(g3);
b0 = limit(b0);
b1 = limit(b1);
b2 = limit(b2);
b3 = limit(b3);
/* first pixel */
PPM_ASSIGN(*pP1, (pixval)r0, (pixval)g0, (pixval)b0);
pP1++;
/* 2nd pixval */
PPM_ASSIGN(*pP1, (pixval)r1, (pixval)g1, (pixval)b1);
pP1++;
/* 3rd pixval */
PPM_ASSIGN(*pP2, (pixval)r2, (pixval)g2, (pixval)b2);
pP2++;
/* 4th pixval */
PPM_ASSIGN(*pP2, (pixval)r3, (pixval)g3, (pixval)b3);
pP2++;
}
ppm_writeppmrow(stdout, pixelrow1, cols, (pixval) 255, 0);
ppm_writeppmrow(stdout, pixelrow2, cols, (pixval) 255, 0);
}
pm_close(stdout);
fclose(yf);
fclose(uf);
fclose(vf);
exit(0);
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.