gstreamer/gst/compositor/blend.h
Thibault Saunier 806ff70590 compositor: Add support for crossfade blending
Crossfading is a bit more complex than just having two pads with the
right keyframes as the blending is not exactly the same.

The difference is in the way we compute the alpha channel, in the case
of crossfading, we have to compute an additive operation between
the destination and the source (factored by the alpha property of both
the input pad alpha property and the crossfading ratio) basically so
that the crossfade result of 2 opaque frames is also fully opaque at any
time in the crossfading process, avoid bleeding through the layer
blending.

Some rationnal can be found in https://phabricator.freedesktop.org/T7773.

https://bugzilla.gnome.org/show_bug.cgi?id=784827
2017-08-03 12:59:43 -04:00

123 lines
5.8 KiB
C

/*
* Copyright (C) 2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
*
* 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 __BLEND_H__
#define __BLEND_H__
#include <gst/gst.h>
#include <gst/video/video.h>
/**
* GstCompositorBlendMode:
* @COMPOSITOR_BLEND_MODE_NORMAL: Normal blending
* @COMPOSITOR_BLEND_MODE_ADDITIVE: Alphas are simply added,
*
* The different modes compositor can use for blending.
*/
typedef enum
{
COMPOSITOR_BLEND_MODE_NORMAL,
COMPOSITOR_BLEND_MODE_ADDITIVE,
} GstCompositorBlendMode;
typedef void (*BlendFunction) (GstVideoFrame *srcframe, gint xpos, gint ypos, gdouble src_alpha, GstVideoFrame * destframe,
GstCompositorBlendMode mode);
typedef void (*FillCheckerFunction) (GstVideoFrame * frame);
typedef void (*FillColorFunction) (GstVideoFrame * frame, gint c1, gint c2, gint c3);
extern BlendFunction gst_compositor_blend_argb;
extern BlendFunction gst_compositor_blend_bgra;
#define gst_compositor_blend_ayuv gst_compositor_blend_argb
#define gst_compositor_blend_abgr gst_compositor_blend_argb
#define gst_compositor_blend_rgba gst_compositor_blend_bgra
#define gst_compositor_blend_ayuv_addition gst_compositor_blend_argb_addition
#define gst_compositor_blend_abgr_addition gst_compositor_blend_argb_addition
#define gst_compositor_blend_rgba_addition gst_compositor_blend_bgra_addition
extern BlendFunction gst_compositor_overlay_argb;
extern BlendFunction gst_compositor_overlay_bgra;
#define gst_compositor_overlay_ayuv gst_compositor_overlay_argb
#define gst_compositor_overlay_abgr gst_compositor_overlay_argb
#define gst_compositor_overlay_abgr gst_compositor_overlay_argb
#define gst_compositor_overlay_rgba gst_compositor_overlay_bgra
extern BlendFunction gst_compositor_blend_i420;
#define gst_compositor_blend_yv12 gst_compositor_blend_i420
extern BlendFunction gst_compositor_blend_nv12;
extern BlendFunction gst_compositor_blend_nv21;
extern BlendFunction gst_compositor_blend_y41b;
extern BlendFunction gst_compositor_blend_y42b;
extern BlendFunction gst_compositor_blend_y444;
extern BlendFunction gst_compositor_blend_rgb;
#define gst_compositor_blend_bgr gst_compositor_blend_rgb
extern BlendFunction gst_compositor_blend_rgbx;
#define gst_compositor_blend_bgrx gst_compositor_blend_rgbx
#define gst_compositor_blend_xrgb gst_compositor_blend_rgbx
#define gst_compositor_blend_xbgr gst_compositor_blend_rgbx
extern BlendFunction gst_compositor_blend_yuy2;
#define gst_compositor_blend_uyvy gst_compositor_blend_yuy2;
#define gst_compositor_blend_yvyu gst_compositor_blend_yuy2;
extern FillCheckerFunction gst_compositor_fill_checker_argb;
#define gst_compositor_fill_checker_abgr gst_compositor_fill_checker_argb
extern FillCheckerFunction gst_compositor_fill_checker_bgra;
#define gst_compositor_fill_checker_rgba gst_compositor_fill_checker_bgra
extern FillCheckerFunction gst_compositor_fill_checker_ayuv;
extern FillCheckerFunction gst_compositor_fill_checker_i420;
#define gst_compositor_fill_checker_yv12 gst_compositor_fill_checker_i420
extern FillCheckerFunction gst_compositor_fill_checker_nv12;
extern FillCheckerFunction gst_compositor_fill_checker_nv21;
extern FillCheckerFunction gst_compositor_fill_checker_y41b;
extern FillCheckerFunction gst_compositor_fill_checker_y42b;
extern FillCheckerFunction gst_compositor_fill_checker_y444;
extern FillCheckerFunction gst_compositor_fill_checker_rgb;
#define gst_compositor_fill_checker_bgr gst_compositor_fill_checker_rgb
extern FillCheckerFunction gst_compositor_fill_checker_rgbx;
#define gst_compositor_fill_checker_bgrx gst_compositor_fill_checker_rgbx
#define gst_compositor_fill_checker_xrgb gst_compositor_fill_checker_rgbx
#define gst_compositor_fill_checker_xbgr gst_compositor_fill_checker_rgbx
extern FillCheckerFunction gst_compositor_fill_checker_yuy2;
#define gst_compositor_fill_checker_yvyu gst_compositor_fill_checker_yuy2;
extern FillCheckerFunction gst_compositor_fill_checker_uyvy;
extern FillColorFunction gst_compositor_fill_color_argb;
extern FillColorFunction gst_compositor_fill_color_abgr;
extern FillColorFunction gst_compositor_fill_color_bgra;
extern FillColorFunction gst_compositor_fill_color_rgba;
extern FillColorFunction gst_compositor_fill_color_ayuv;
extern FillColorFunction gst_compositor_fill_color_i420;
extern FillColorFunction gst_compositor_fill_color_yv12;
extern FillColorFunction gst_compositor_fill_color_nv12;
#define gst_compositor_fill_color_nv21 gst_compositor_fill_color_nv12;
extern FillColorFunction gst_compositor_fill_color_y41b;
extern FillColorFunction gst_compositor_fill_color_y42b;
extern FillColorFunction gst_compositor_fill_color_y444;
extern FillColorFunction gst_compositor_fill_color_rgb;
extern FillColorFunction gst_compositor_fill_color_bgr;
extern FillColorFunction gst_compositor_fill_color_xrgb;
extern FillColorFunction gst_compositor_fill_color_xbgr;
extern FillColorFunction gst_compositor_fill_color_rgbx;
extern FillColorFunction gst_compositor_fill_color_bgrx;
extern FillColorFunction gst_compositor_fill_color_yuy2;
extern FillColorFunction gst_compositor_fill_color_yvyu;
extern FillColorFunction gst_compositor_fill_color_uyvy;
void gst_compositor_init_blend (void);
#endif /* __BLEND_H__ */