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/*
# RGB <-> YUV conversion routines
# (C) 2008 Hans de Goede <j.w.r.degoede@hhs.nl>
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# This program 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
# GNU General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#define RGB2YUV(r,g,b,y,u,v) \
(y) = (( 8453*(r) + 16594*(g) + 3223*(b) + 524288) >> 15); \
(u) = (( -4878*(r) - 9578*(g) + 14456*(b) + 4210688) >> 15); \
(v) = (( 14456*(r) - 12105*(g) - 2351*(b) + 4210688) >> 15)
#define YUV2R(y, u, v) ({ \
int r = (y) + ((((v)-128)*1436) >> 10); r > 255 ? 255 : r < 0 ? 0 : r; })
#define YUV2G(y, u, v) ({ \
int g = (y) - ((((u)-128)*352 + ((v)-128)*731) >> 10); g > 255 ? 255 : g < 0 ? 0 : g; })
#define YUV2B(y, u, v) ({ \
int b = (y) + ((((u)-128)*1814) >> 10); b > 255 ? 255 : b < 0 ? 0 : b; })
#define CLIP(color) (unsigned char)(((color)>0xFF)?0xff:(((color)<0)?0:(color)))
void v4lconvert_yuv420_to_bgr24(const unsigned char *src, unsigned char *dest,
int width, int height)
{
int i,j;
const unsigned char *ysrc = src;
const unsigned char *usrc = src + width * height;
const unsigned char *vsrc = usrc + (width * height) / 4;
for (i = 0; i < height; i++) {
for (j = 0; j < width; j += 2) {
#if 1 /* fast slightly less accurate multiplication free code */
int u1 = (((*usrc - 128) << 7) + (*usrc - 128)) >> 6;
int rg = (((*usrc - 128) << 1) + (*usrc - 128) +
((*vsrc - 128) << 2) + ((*vsrc - 128) << 1)) >> 3;
int v1 = (((*vsrc - 128) << 1) + (*vsrc - 128)) >> 1;
*dest++ = CLIP(*ysrc + u1);
*dest++ = CLIP(*ysrc - rg);
*dest++ = CLIP(*ysrc + v1);
ysrc++;
*dest++ = CLIP(*ysrc + u1);
*dest++ = CLIP(*ysrc - rg);
*dest++ = CLIP(*ysrc + v1);
#else
*dest++ = YUV2B(*ysrc, *usrc, *vsrc);
*dest++ = YUV2G(*ysrc, *usrc, *vsrc);
*dest++ = YUV2R(*ysrc, *usrc, *vsrc);
ysrc++;
*dest++ = YUV2B(*ysrc, *usrc, *vsrc);
*dest++ = YUV2G(*ysrc, *usrc, *vsrc);
*dest++ = YUV2R(*ysrc, *usrc, *vsrc);
#endif
ysrc++;
usrc++;
vsrc++;
}
/* Rewind u and v for next line */
if (i&1) {
usrc -= width / 2;
vsrc -= width / 2;
}
}
}
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