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videomixer: Fix I420 blending to actually do something

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For this we a) implement the checkers filling and b)
actually blend the src/dest by using the src alpha value
from the pad.
This commit is contained in:
Sebastian Dröge 2009-05-28 13:35:52 +02:00
parent ad1f79fd81
commit 699b696db8
1 changed files with 33 additions and 10 deletions
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43
gst/videomixer/blend_i420.c
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@ -185,13 +185,18 @@
inline static void
gst_i420_do_blend (guint8 * src, guint8 * dest,
gint src_stride, gint dest_stride, gint src_width, gint src_height)
gint src_stride, gint dest_stride, gint src_width, gint src_height,
gint dest_width, gdouble src_alpha)
{
int i;
int i, j;
for (i = 0; i < src_height; i++) {
memcpy (dest, src, src_width);
src += src_stride;
dest += dest_stride;
for (j = 0; j < src_width; j++) {
*dest = src_alpha * (*dest) + (1. - src_alpha) * (*src);
dest++;
src++;
}
src += src_stride - src_width;
dest += dest_stride - dest_width;
}
}
@ -246,7 +251,8 @@ gst_videomixer_blend_i420_i420 (guint8 * src, gint xpos, gint ypos,
gst_i420_do_blend (b_src + xoffset + yoffset * VIDEO_Y_ROWSTRIDE (src_width),
b_dest + xpos + ypos * VIDEO_Y_ROWSTRIDE (dest_width),
VIDEO_Y_ROWSTRIDE (src_width),
VIDEO_Y_ROWSTRIDE (dest_width), b_src_width, b_src_height);
VIDEO_Y_ROWSTRIDE (dest_width), b_src_width, b_src_height,
dest_width, src_alpha);
b_src = src + VIDEO_U_OFFSET (src_width, src_height);
b_dest = dest + VIDEO_U_OFFSET (dest_width, dest_height);
@ -255,7 +261,8 @@ gst_videomixer_blend_i420_i420 (guint8 * src, gint xpos, gint ypos,
yoffset / 2 * VIDEO_U_ROWSTRIDE (src_width),
b_dest + xpos / 2 + ypos / 2 * VIDEO_U_ROWSTRIDE (dest_width),
VIDEO_U_ROWSTRIDE (src_width), VIDEO_U_ROWSTRIDE (dest_width),
b_src_width / 2, GST_ROUND_UP_2 (b_src_height) / 2);
b_src_width / 2, GST_ROUND_UP_2 (b_src_height) / 2, dest_width / 2,
src_alpha);
b_src = src + VIDEO_V_OFFSET (src_width, src_height);
b_dest = dest + VIDEO_V_OFFSET (dest_width, dest_height);
@ -264,7 +271,8 @@ gst_videomixer_blend_i420_i420 (guint8 * src, gint xpos, gint ypos,
yoffset / 2 * VIDEO_V_ROWSTRIDE (src_width),
b_dest + xpos / 2 + ypos / 2 * VIDEO_V_ROWSTRIDE (dest_width),
VIDEO_V_ROWSTRIDE (src_width), VIDEO_V_ROWSTRIDE (dest_width),
b_src_width / 2, GST_ROUND_UP_2 (b_src_height) / 2);
b_src_width / 2, GST_ROUND_UP_2 (b_src_height) / 2, dest_width / 2,
src_alpha);
}
#undef BLEND_MODE
@ -273,8 +281,23 @@ gst_videomixer_blend_i420_i420 (guint8 * src, gint xpos, gint ypos,
void
gst_videomixer_fill_i420_checker (guint8 * dest, gint width, gint height)
{
//TODO: implementation of this method in i420mixer.c was for AYUV, which has 32bpp ans is packed
//I420 has 12 bpp and is planar
int size;
gint i, j;
static int tab[] = { 80, 160, 80, 160 };
guint8 *p = dest;
for (i = 0; i < height; i++) {
for (j = 0; j < width; j++) {
*p++ = tab[((i & 0x8) >> 3) + ((j & 0x8) >> 3)];
}
p += VIDEO_Y_ROWSTRIDE (width) - width;
}
size = (VIDEO_U_ROWSTRIDE (width) * height) / 2;
memset (dest + VIDEO_U_OFFSET (width, height), 0x80, size);
size = (VIDEO_V_ROWSTRIDE (width) * height) / 2;
memset (dest + VIDEO_V_OFFSET (width, height), 0x80, size);
}
void