gstreamer/ext/cairo/gstcairooverlay.h
Sebastian Dröge 9844bdbf7a cairooverlay: Add property for drawing on a transparent surface and then blending
This allows us to use the GstVideoOverlayComposition API and correctly
handle pre-multiplied alpha, while also only doing the alpha conversion
once instead of twice for the whole frame.

At a later point we can attach the meta to the buffer instead of
blending ourselves if downstream supports that.

https://bugzilla.gnome.org/show_bug.cgi?id=797091
2018-10-03 23:20:10 +03:00

59 lines
1.9 KiB
C

/* GStreamer
* Copyright (C) <2011> Jon Nordby <jononor@gmail.com>
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GST_CAIRO_OVERLAY_H__
#define __GST_CAIRO_OVERLAY_H__
#include <gst/gst.h>
#include <gst/video/video.h>
#include <gst/video/gstvideofilter.h>
#include <cairo.h>
#include <cairo-gobject.h>
G_BEGIN_DECLS
#define GST_TYPE_CAIRO_OVERLAY \
(gst_cairo_overlay_get_type())
#define GST_CAIRO_OVERLAY(obj) \
(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_CAIRO_OVERLAY,GstCairoOverlay))
#define GST_CAIRO_OVERLAY_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_CAIRO_OVERLAY,GstCairoOverlayClass))
#define GST_IS_CAIRO_OVERLAY(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_CAIRO_OVERLAY))
#define GST_IS_CAIRO_OVERLAY_CLASS(klass) \
(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_CAIRO_OVERLAY))
typedef struct _GstCairoOverlay GstCairoOverlay;
typedef struct _GstCairoOverlayClass GstCairoOverlayClass;
struct _GstCairoOverlay {
GstVideoFilter video_filter;
gboolean draw_on_transparent_surface;
};
struct _GstCairoOverlayClass {
GstVideoFilterClass video_filter_class;
};
GType gst_cairo_overlay_get_type (void);
G_END_DECLS
#endif /* __GST_CAIRO_OVERLAY_H__ */