gstreamer/gst/geometrictransform/gstsquare.c
Filippo Argiolas 5c4915d917 geometrictransform: new filter "square"
Ports gleffects "square" filter to geometrictransform.
Maps a region around the center into a zoomed square and smoothly get
back to normal zoom. With faces it makes a funny "cube-face" effect.

https://bugzilla.gnome.org/show_bug.cgi?id=625722
2010-08-02 20:14:23 +02:00

132 lines
4.3 KiB
C

/*
* GStreamer
* Copyright (C) 2010 Filippo Argiolas <filippo.argiolas@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Alternatively, the contents of this file may be used under the
* GNU Lesser General Public License Version 2.1 (the "LGPL"), in
* which case the following provisions apply instead of the ones
* mentioned above:
*
* 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.
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <gst/gst.h>
#include <math.h>
#include "gstsquare.h"
GST_DEBUG_CATEGORY_STATIC (gst_square_debug);
#define GST_CAT_DEFAULT gst_square_debug
GST_BOILERPLATE (GstSquare, gst_square, GstGeometricTransform,
GST_TYPE_GEOMETRIC_TRANSFORM);
/* GObject vmethod implementations */
static void
gst_square_base_init (gpointer gclass)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (gclass);
gst_element_class_set_details_simple (element_class,
"square",
"Transform/Effect/Video",
"Distort center part of the image into a square",
"Filippo Argiolas <filippo.argiolas@gmail.com");
}
static gboolean
square_map (GstGeometricTransform * gt, gint x, gint y, gdouble * in_x,
gdouble * in_y)
{
GstSquare *square = GST_SQUARE_CAST (gt);
gdouble norm_x;
gdouble norm_y;
gdouble width = gt->width;
gdouble height = gt->height;
/* normalize in ((-1.0, -1.0), (1.0, 1.0) */
norm_x = 2.0 * x / width - 1.0;
norm_y = 2.0 * y / height - 1.0;
/* transform */
/* zoom at the center, smoothstep around half quadrant and get back to normal */
norm_x *= 0.5 * (1.0 + smoothstep (0.375, 0.625, ABS (norm_x)));
norm_y *= 0.5 * (1.0 + smoothstep (0.375, 0.625, ABS (norm_y)));
/* unnormalize */
*in_x = 0.5 * (norm_x + 1.0) * width;
*in_y = 0.5 * (norm_y + 1.0) * height;
GST_DEBUG_OBJECT (square, "Inversely mapped %d %d into %lf %lf",
x, y, *in_x, *in_y);
return TRUE;
}
static void
gst_square_class_init (GstSquareClass * klass)
{
GObjectClass *gobject_class;
GstGeometricTransformClass *gstgt_class;
gobject_class = (GObjectClass *) klass;
gstgt_class = (GstGeometricTransformClass *) klass;
parent_class = g_type_class_peek_parent (klass);
gstgt_class->map_func = square_map;
}
static void
gst_square_init (GstSquare * filter, GstSquareClass * gclass)
{
GstGeometricTransform *gt = GST_GEOMETRIC_TRANSFORM (filter);
gt->off_edge_pixels = GST_GT_OFF_EDGES_PIXELS_CLAMP;
}
gboolean
gst_square_plugin_init (GstPlugin * plugin)
{
GST_DEBUG_CATEGORY_INIT (gst_square_debug, "square", 0, "square");
return gst_element_register (plugin, "square", GST_RANK_NONE,
GST_TYPE_SQUARE);
}