gstreamer/gst/videomixer/blend_bgra.c

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/*
* Copyright (C) 2009 Alex Ugarte <augarte@vicomtech.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <gst/gst.h>
#define BLEND_NORMAL(B1,G1,R1,B2,G2,R2,B,G,R,alpha) \
B = ((B1*(255-alpha))+(B2*alpha))>>8; \
G = ((G1*(255-alpha))+(G2*alpha))>>8; \
R = ((R1*(255-alpha))+(R2*alpha))>>8;
#define BLEND_MODE BLEND_NORMAL
void
gst_videomixer_blend_bgra_bgra (guint8 * src, gint xpos, gint ypos,
gint src_width, gint src_height, gdouble src_alpha,
guint8 * dest, gint dest_width, gint dest_height)
{
gint alpha, b_alpha;
gint i, j;
gint src_stride, dest_stride;
gint src_add, dest_add;
gint B, G, R;
src_stride = src_width * 4;
dest_stride = dest_width * 4;
b_alpha = (gint) (src_alpha * 255);
/* adjust src pointers for negative sizes */
if (xpos < 0) {
src += -xpos * 4;
src_width -= -xpos;
xpos = 0;
}
if (ypos < 0) {
src += -ypos * src_stride;
src_height -= -ypos;
ypos = 0;
}
/* adjust width/height if the src is bigger than dest */
if (xpos + src_width > dest_width) {
src_width = dest_width - xpos;
}
if (ypos + src_height > dest_height) {
src_height = dest_height - ypos;
}
src_add = src_stride - (4 * src_width);
dest_add = dest_stride - (4 * src_width);
dest = dest + 4 * xpos + (ypos * dest_stride);
/* we convert a square of 2x2 samples to generate 4 Luma and 2 chroma samples */
for (i = 0; i < src_height; i++) {
for (j = 0; j < src_width; j++) {
alpha = (src[3] * b_alpha) >> 8;
BLEND_MODE (dest[0], dest[1], dest[2], src[0], src[1], src[2],
B, G, R, alpha);
dest[0] = B;
dest[1] = G;
dest[2] = R;
dest[3] = 0xff;
src += 4;
dest += 4;
}
src += src_add;
dest += dest_add;
}
}
#undef BLEND_MODE
/* fill a buffer with a checkerboard pattern */
void
gst_videomixer_fill_bgra_checker (guint8 * dest, gint width, gint height)
{
gint i, j;
static int tab[] = { 80, 160, 80, 160 };
for (i = 0; i < height; i++) {
for (j = 0; j < width; j++) {
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*dest++ = tab[((i & 0x8) >> 3) + ((j & 0x8) >> 3)]; /* blue */
*dest++ = tab[((i & 0x8) >> 3) + ((j & 0x8) >> 3)]; /* green */
*dest++ = tab[((i & 0x8) >> 3) + ((j & 0x8) >> 3)]; /* red */
*dest++ = 0xFF; /* alpha */
}
}
}
void
gst_videomixer_fill_bgra_color (guint8 * dest, gint width, gint height,
gint colY, gint colU, gint colV)
{
gint red, green, blue;
gint i, j;
red = CLAMP (1.164 * (colY - 16) + 1.596 * (colV - 128), 0, 255);
green =
CLAMP (1.164 * (colY - 16) - 0.813 * (colV - 128) - 0.391 * (colU - 128),
0, 255);
blue = CLAMP (1.164 * (colY - 16) + 2.018 * (colU - 128), 0, 255);
for (i = 0; i < height; i++) {
for (j = 0; j < width; j++) {
*dest++ = blue;
*dest++ = green;
*dest++ = red;
*dest++ = 0xff;
}
}
}
size_t
gst_videomixer_calculate_frame_size_bgra (gint width, gint height)
{
return GST_ROUND_UP_4 (width) * height * 4;
}