source: BAORadio/libindi/v1.0.1/libs/webcam/ccvt_c2.c@ 692

/*  CCVT_C2: Convert an image from yuv colourspace to rgb 
    Copyright (C) 2001 Tony Hague <no.email@noemail.com>

    
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 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 General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

    For questions, remarks, patches, etc. for this program, the author can be
    reached at nemosoft@smcc.demon.nl.
*/

#include "ccvt.h"
#include "ccvt_types.h"

/* by suitable definition of PIXTYPE, can do yuv to rgb or bgr, with or
without word alignment */

/* This doesn't exactly earn a prize in a programming beauty contest. */

#define WHOLE_FUNC2RGB(type)                    \
        const unsigned char *y1, *y2, *u, *v;   \
        PIXTYPE_##type *l1, *l2;                \
        int r, g, b, cr, cg, cb, yp, j, i;      \
                                                \
        if ((width & 1) || (height & 1))        \
                return;                         \
                                                \
        l1 = (PIXTYPE_##type *)dst;             \
        l2 = l1 + width;                        \
        y1 = (unsigned char *)src;              \
        y2 = y1 + width;                        \
        u = (unsigned char *)src + width * height;              \
        v = u + (width * height) / 4;           \
        j = height / 2;                         \
        while (j--) {                           \
                i = width / 2;                  \
                while (i--) {                   \
                        /* Since U & V are valid for 4 pixels, repeat code 4    \
                           times for different Y */                             \
                        cb = ((*u-128) * 454)>>8;                               \
                        cr = ((*v-128) * 359)>>8;                               \
                        cg = ((*v-128) * 183 + (*u-128) * 88)>>8;               \
                                                \
                        yp = *(y1++);           \
                        r = yp + cr;            \
                        b = yp + cb;            \
                        g = yp - cg;            \
                        SAT(r);                 \
                        SAT(g);                 \
                        SAT(b);                 \
                        l1->b = b;              \
                        l1->g = g;              \
                        l1->r = r;              \
                        l1++;                   \
                                                \
                        yp = *(y1++);           \
                        r = yp + cr;            \
                        b = yp + cb;            \
                        g = yp - cg;            \
                        SAT(r);                 \
                        SAT(g);                 \
                        SAT(b);                 \
                        l1->b = b;              \
                        l1->g = g;              \
                        l1->r = r;              \
                        l1++;                   \
                                                \
                        yp = *(y2++);           \
                        r = yp + cr;            \
                        b = yp + cb;            \
                        g = yp - cg;            \
                        SAT(r);                 \
                        SAT(g);                 \
                        SAT(b);                 \
                        l2->b = b;              \
                        l2->g = g;              \
                        l2->r = r;              \
                        l2++;                   \
                                                \
                        yp = *(y2++);           \
                        r = yp + cr;            \
                        b = yp + cb;            \
                        g = yp - cg;            \
                        SAT(r);                 \
                        SAT(g);                 \
                        SAT(b);                 \
                        l2->b = b;              \
                        l2->g = g;              \
                        l2->r = r;              \
                        l2++;                   \
                                                \
                        u++;                    \
                        v++;                    \
                }                               \
                y1 = y2;                        \
                y2 += width;                    \
                l1 = l2;                        \
                l2 += width;                    \
        }




void ccvt_420p_bgr32(int width, int height, const void *src, void *dst)
{
        WHOLE_FUNC2RGB(bgr32)
}

void ccvt_420p_bgr24(int width, int height, const void *src, void *dst)
{
        WHOLE_FUNC2RGB(bgr24)
}

void ccvt_420p_rgb32(int width, int height, const void *src, void *dst)
{
        WHOLE_FUNC2RGB(rgb32)
}

void ccvt_420p_rgb24(int width, int height, const void *src, void *dst)
{
        WHOLE_FUNC2RGB(rgb24)
}