source: python/trunk/Modules/yuvconvert.c

#include "yuv.h"

void
yuv_sv411_to_cl422dc(int invert, void *data, void *yuv, int width, int height)
{
    struct yuv411 *in = data;
    struct yuv422 *out_even = yuv;
    struct yuv422 *out_odd = out_even + width / 2;
    int i, j;                   /* counters */

    for (i = height / 2; i--; ) {
        for (j = width / 4; j--; ) {
            YUV422_Y0(*out_even) = YUV411_Y00(*in);
            YUV422_U0(*out_even) = YUV411_U00(*in);
            YUV422_V0(*out_even) = YUV411_V00(*in);
            YUV422_Y1(*out_even) = YUV411_Y01(*in);
            out_even++;
            YUV422_Y0(*out_even) = YUV411_Y02(*in);
            YUV422_U0(*out_even) = YUV411_U02(*in);
            YUV422_V0(*out_even) = YUV411_V02(*in);
            YUV422_Y1(*out_even) = YUV411_Y03(*in);
            out_even++;
            YUV422_Y0(*out_odd) = YUV411_Y10(*in);
            YUV422_U0(*out_odd) = YUV411_U10(*in);
            YUV422_V0(*out_odd) = YUV411_V10(*in);
            YUV422_Y1(*out_odd) = YUV411_Y11(*in);
            out_odd++;
            YUV422_Y0(*out_odd) = YUV411_Y12(*in);
            YUV422_U0(*out_odd) = YUV411_U12(*in);
            YUV422_V0(*out_odd) = YUV411_V12(*in);
            YUV422_Y1(*out_odd) = YUV411_Y13(*in);
            out_odd++;
            in++;
        }
        out_even += width / 2;
        out_odd += width / 2;
    }
}

void
yuv_sv411_to_cl422dc_quartersize(int invert, void *data, void *yuv,
                                 int width, int height)
{
    int w4 = width / 4;         /* quarter of width is used often */
    struct yuv411 *in_even = data;
    struct yuv411 *in_odd = in_even + w4;
    struct yuv422 *out_even = yuv;
    struct yuv422 *out_odd = out_even + w4;
    int i, j;                   /* counters */
    int u, v;                   /* U and V values */

    for (i = height / 4; i--; ) {
        for (j = w4; j--; ) {
            u = YUV411_U00(*in_even);
            v = YUV411_V00(*in_even);

            YUV422_Y0(*out_even) = YUV411_Y00(*in_even);
            YUV422_U0(*out_even) = u;
            YUV422_V0(*out_even) = v;
            YUV422_Y1(*out_even) = YUV411_Y02(*in_even);

            YUV422_Y0(*out_odd) = YUV411_Y10(*in_odd);
            YUV422_U0(*out_odd) = u;
            YUV422_V0(*out_odd) = v;
            YUV422_Y1(*out_odd) = YUV411_Y12(*in_odd);

            in_even++;
            in_odd++;
            out_even++;
            out_odd++;
        }
        in_even += w4;
        in_odd += w4;
        out_even += w4;
        out_odd += w4;
    }
}

void
yuv_sv411_to_cl422dc_sixteenthsize(int invert, void *data, void *yuv,
                                   int width, int height)
{
    int w4_3 = 3 * width / 4; /* three quarters of width is used often */
    int w8 = width / 8;         /* and so is one eighth */
    struct yuv411 *in_even = data;
    struct yuv411 *in_odd = in_even + width / 2;
    struct yuv422 *out_even = yuv;
    struct yuv422 *out_odd = out_even + w8;
    int i, j;                   /* counters */
    int u, v;                   /* U and V values */

    for (i = height / 8; i--; ) {
        for (j = w8; j--; ) {
            u = YUV411_U00(in_even[0]);
            v = YUV411_V00(in_even[0]);

            YUV422_Y0(*out_even) = YUV411_Y00(in_even[0]);
            YUV422_U0(*out_even) = u;
            YUV422_V0(*out_even) = v;
            YUV422_Y1(*out_even) = YUV411_Y00(in_even[1]);

            YUV422_Y0(*out_odd) = YUV411_Y00(in_odd[0]);
            YUV422_U0(*out_odd) = u;
            YUV422_V0(*out_odd) = v;
            YUV422_Y1(*out_odd) = YUV411_Y00(in_even[1]);

            in_even += 2;
            in_odd += 2;
            out_even++;
            out_odd++;
        }
        in_even += w4_3;
        in_odd += w4_3;
        out_even += w8;
        out_odd += w8;
    }
}