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/* yuvtoppm.c - convert Abekas YUV bytes into a portable pixmap
**
** by Marc Boucher
** Internet: marc@PostImage.COM
**
** Based on Example Conversion Program, A60/A64 Digital Video Interface
** Manual, page 69
**
** Uses integer arithmetic rather than floating point for better performance
**
** Copyright (C) 1991 by DHD PostImage Inc.
** Copyright (C) 1987 by Abekas Video Systems Inc.
** Copyright (C) 1991 by Jef Poskanzer.
**
** 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;
pixel *pixrow;
int argn, rows, cols, row, i;
char *usage = "<width> <height> [yuvfile]";
long *yuvbuf;
ppm_init(&argc, argv);
argn = 1;
if (argn + 2 > argc)
pm_usage(usage);
cols = atoi(argv[argn++]);
rows = atoi(argv[argn++]);
if (cols <= 0 || rows <= 0)
pm_usage(usage);
if (argn < argc) {
ifp = pm_openr(argv[argn]);
++argn;
} else
ifp = stdin;
if (argn != argc)
pm_usage(usage);
if (255 > PGM_MAXMAXVAL)
pm_error(
"maxval of 255 is too large - try recompiling with a larger pixval type");
ppm_writeppminit(stdout, cols, rows, (pixval) 255, 0);
pixrow = ppm_allocrow(cols);
yuvbuf = (long *) pm_allocrow(cols, 2);
for (row = 0; row < rows; ++row) {
long tmp, y, u, v, y1, r, g, b, *yuvptr;
register pixel *pP;
register int col;
fread(yuvbuf, cols * 2, 1, ifp);
for (col = 0, pP = pixrow, yuvptr = yuvbuf; col < cols; col += 2) {
tmp = *yuvptr++;
u = (0xff & (tmp >> 24)) - 128;
y = ((0xff & (tmp >> 16)) - 16);
if (y < 0) y = 0;
v = (0xff & (tmp >> 8)) - 128;
y1 = ((0xff & tmp) - 16);
if (y1 < 0) y1 = 0;
r = 104635 * v;
g = -25690 * u + -53294 * v;
b = 132278 * u;
y*=76310; y1*=76310;
PPM_ASSIGN(*pP, limit(r+y), limit(g+y), limit(b+y));
pP++;
PPM_ASSIGN(*pP, limit(r+y1), limit(g+y1), limit(b+y1));
pP++;
}
ppm_writeppmrow(stdout, pixrow, cols, (pixval) 255, 0);
}
pm_close(ifp);
pm_close(stdout);
exit(0);
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.