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videomixer: Blend BGRA ourselves instead of using Cairo

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This commit is contained in:
Sebastian Dröge 2009-05-28 13:04:51 +02:00
parent 82abbeaf4f
commit f66906e891
2 changed files with 58 additions and 25 deletions
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4
gst/videomixer/Makefile.am
View file

@ -1,8 +1,8 @@
plugin_LTLIBRARIES = libgstvideomixer.la
libgstvideomixer_la_SOURCES = videomixer.c blend_ayuv.c blend_bgra.c blend_i420.c
libgstvideomixer_la_CFLAGS = $(GST_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CONTROLLER_CFLAGS) $(GST_PLUGINS_BASE_CFLAGS) $(CAIRO_CFLAGS)
libgstvideomixer_la_LIBADD = $(GST_LIBS) $(GST_BASE_LIBS) $(GST_CONTROLLER_LIBS) $(CAIRO_LIBS)
libgstvideomixer_la_CFLAGS = $(GST_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CONTROLLER_CFLAGS) $(GST_PLUGINS_BASE_CFLAGS)
libgstvideomixer_la_LIBADD = $(GST_LIBS) $(GST_BASE_LIBS) $(GST_CONTROLLER_LIBS)
libgstvideomixer_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
libgstvideomixer_la_LIBTOOLFLAGS = --tag=disable-static

79
gst/videomixer/blend_bgra.c
View file

@ -19,41 +19,74 @@
#include <gst/gst.h>
#include <cairo.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)
{
cairo_surface_t *srcSurface = 0;
cairo_surface_t *destSurface = 0;
cairo_t *cairo = 0;
gint alpha, b_alpha;
gint i, j;
gint src_stride, dest_stride;
gint src_add, dest_add;
gint B, G, R;
srcSurface =
cairo_image_surface_create_for_data (src, CAIRO_FORMAT_ARGB32, src_width,
src_height, src_width * 4);
g_assert (srcSurface);
destSurface =
cairo_image_surface_create_for_data (dest, CAIRO_FORMAT_ARGB32,
dest_width, dest_height, dest_width * 4);
g_assert (destSurface);
cairo = cairo_create (destSurface);
g_assert (cairo);
src_stride = src_width * 4;
dest_stride = dest_width * 4;
//copy source buffer in destiation
cairo_translate (cairo, xpos, ypos);
cairo_set_source_surface (cairo, srcSurface, 0, 0);
cairo_paint (cairo);
b_alpha = (gint) (src_alpha * 255);
cairo_surface_finish (srcSurface);
cairo_surface_finish (destSurface);
cairo_surface_destroy (srcSurface);
cairo_surface_destroy (destSurface);
cairo_destroy (cairo);
/* 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[1], dest[2], dest[3], src[1], src[2], src[3],
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)