gstreamer/gst/geometrictransform/gstrotate.c
2021-04-11 16:16:55 +00:00

217 lines
6.4 KiB
C

/*
* GStreamer
* Copyright (C) 2010 Thiago Santos <thiago.sousa.santos@collabora.co.uk>
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/*
* Thanks to Jerry Huxtable <http://www.jhlabs.com> work on its java
* image editor and filters. The algorithms here were extracted from
* his code.
*/
/**
* SECTION:element-rotate
* @title: rotate
* @see_also: geometrictransform
*
* The rotate element transforms the image by rotating it by a specified angle.
*
* ## Example launch line
* |[
* gst-launch-1.0 -v videotestsrc ! rotate angle=0.78 ! videoconvert ! autovideosink
* ]|
*
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <gst/gst.h>
#include <math.h>
#include "geometricmath.h"
#include "gstrotate.h"
GST_DEBUG_CATEGORY_STATIC (gst_rotate_debug);
#define GST_CAT_DEFAULT gst_rotate_debug
enum
{
PROP_0,
PROP_ANGLE
};
#define DEFAULT_ANGLE 0
#define gst_rotate_parent_class parent_class
G_DEFINE_TYPE (GstRotate, gst_rotate, GST_TYPE_GEOMETRIC_TRANSFORM);
GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (rotate, "rotate", GST_RANK_NONE,
GST_TYPE_ROTATE, GST_DEBUG_CATEGORY_INIT (gst_rotate_debug, "rotate", 0,
"rotate"));
static void
gst_rotate_set_property (GObject * object, guint prop_id, const GValue * value,
GParamSpec * pspec)
{
GstRotate *rotate;
GstGeometricTransform *gt;
gdouble v;
gt = GST_GEOMETRIC_TRANSFORM_CAST (object);
rotate = GST_ROTATE_CAST (object);
GST_OBJECT_LOCK (rotate);
switch (prop_id) {
case PROP_ANGLE:
v = g_value_get_double (value);
if (v != rotate->angle) {
rotate->angle = v;
gst_geometric_transform_set_need_remap (gt);
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
GST_OBJECT_UNLOCK (rotate);
}
static void
gst_rotate_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstRotate *rotate;
rotate = GST_ROTATE_CAST (object);
switch (prop_id) {
case PROP_ANGLE:
g_value_set_double (value, rotate->angle);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
rotate_map (GstGeometricTransform * gt, gint x, gint y, gdouble * in_x,
gdouble * in_y)
{
GstRotate *rotate = GST_ROTATE_CAST (gt);
gint w, h;
gdouble cix, ciy, cox, coy; /* centers, in/out x/y */
gdouble ai, ao, ar; /* angles, in/out/rotate (radians) */
gdouble r; /* radius */
gdouble xi, yi, xo, yo; /* positions in/out x/y */
/* input and output image height and width */
w = gt->width;
h = gt->height;
/* our parameters */
ar = rotate->angle; /* angle of rotation */
/* get in and out centers */
cox = 0.5 * w;
coy = 0.5 * h;
cix = cox;
ciy = coy;
/* convert output image position to polar form */
xo = x - cox;
yo = y - coy;
ao = atan2 (yo, xo);
r = sqrt (xo * xo + yo * yo);
/* perform rotation backward to get input image rotation
* this seems wrong, but rotation from in-->out is counterclockwise */
ai = ao + ar;
/* back to rectangular for input image position */
xi = r * cos (ai);
yi = r * sin (ai);
/* restore center offset, return values to caller */
*in_x = xi + cix;
*in_y = yi + ciy;
GST_DEBUG_OBJECT (rotate, "Inversely mapped %d %d into %lf %lf",
x, y, *in_x, *in_y);
return TRUE;
}
static void
gst_rotate_class_init (GstRotateClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
GstGeometricTransformClass *gstgt_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gstgt_class = (GstGeometricTransformClass *) klass;
gst_element_class_set_static_metadata (gstelement_class,
"rotate",
"Transform/Effect/Video",
"Rotates the picture by an arbitrary angle",
"Thiago Santos<thiago.sousa.santos@collabora.co.uk>");
gobject_class->set_property = gst_rotate_set_property;
gobject_class->get_property = gst_rotate_get_property;
g_object_class_install_property (gobject_class, PROP_ANGLE,
g_param_spec_double ("angle", "angle",
"Angle by which the picture is rotated, in radians",
-G_MAXDOUBLE, G_MAXDOUBLE, DEFAULT_ANGLE,
GST_PARAM_CONTROLLABLE | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
gstgt_class->map_func = rotate_map;
}
static void
gst_rotate_init (GstRotate * filter)
{
filter->angle = DEFAULT_ANGLE;
}