gstreamer/gst/geometrictransform/gstperspective.c

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/*
* GStreamer
* Copyright (C) 2010 Thiago Santos <thiago.sousa.santos@collabora.co.uk>
* Copyright (C) 2013 Antonio Ospite <ospite@studenti.unina.it>
*
* 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.
*/
/*
* Perspective matrix multiplication taken from:
* http://docs.oracle.com/cd/E17802_01/products/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/PerspectiveTransform.html
*/
/**
* SECTION:element-perspective
* @title: perspective
* @see_also: geometrictransform
*
* The perspective element applies a 2D perspective transform.
*
* ## Example launch line
* |[
* gst-launch-1.0 -v videotestsrc ! perspective ! videoconvert ! autovideosink
* ]|
*
*/
/* FIXME: suppress warnings for deprecated API such as GValueArray
* with newer GLib versions (>= 2.31.0)
*
* It is just not possible to switch to GArray yet because the python API in
* 1.2.0 still passes iterable properties as GValueArray */
#define GLIB_DISABLE_DEPRECATION_WARNINGS
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <gst/gst.h>
#include "gstperspective.h"
GST_DEBUG_CATEGORY_STATIC (gst_perspective_debug);
#define GST_CAT_DEFAULT gst_perspective_debug
enum
{
PROP_0,
PROP_MATRIX
};
#define gst_perspective_parent_class parent_class
G_DEFINE_TYPE (GstPerspective, gst_perspective, GST_TYPE_GEOMETRIC_TRANSFORM);
GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (perspective, "perspective",
GST_RANK_NONE, GST_TYPE_PERSPECTIVE,
GST_DEBUG_CATEGORY_INIT (gst_perspective_debug, "perspective", 0,
"perspective"));
static GValueArray *
get_array_from_matrix (GstPerspective * self)
{
GValue v = { 0, };
GValueArray *va;
int i;
va = g_value_array_new (1);
for (i = 0; i < 9; i++) {
g_value_init (&v, G_TYPE_DOUBLE);
g_value_set_double (&v, self->matrix[i]);
g_value_array_append (va, &v);
g_value_unset (&v);
}
return va;
}
static gboolean
set_matrix_from_array (GstPerspective * self, GValueArray * va)
{
guint i;
if (!va) {
GST_WARNING ("Invalid parameter");
return FALSE;
}
if (va->n_values != 9) {
GST_WARNING ("Invalid number of elements: %d", va->n_values);
return FALSE;
}
for (i = 0; i < va->n_values; i++) {
GValue *v = g_value_array_get_nth (va, i);
self->matrix[i] = g_value_get_double (v);
}
return TRUE;
}
static void
gst_perspective_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstPerspective *perspective;
GstGeometricTransform *gt;
gboolean matrix_ok;
gt = GST_GEOMETRIC_TRANSFORM_CAST (object);
perspective = GST_PERSPECTIVE_CAST (object);
GST_OBJECT_LOCK (perspective);
switch (prop_id) {
case PROP_MATRIX:
matrix_ok =
set_matrix_from_array (perspective, g_value_get_boxed (value));
if (matrix_ok) {
gst_geometric_transform_set_need_remap (gt);
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
GST_OBJECT_UNLOCK (perspective);
}
static void
gst_perspective_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstPerspective *perspective;
perspective = GST_PERSPECTIVE_CAST (object);
switch (prop_id) {
case PROP_MATRIX:
g_value_set_boxed (value, get_array_from_matrix (perspective));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
perspective_map (GstGeometricTransform * gt, gint x, gint y, gdouble * in_x,
gdouble * in_y)
{
GstPerspective *perspective = GST_PERSPECTIVE_CAST (gt);
gdouble *m;
gdouble xp, yp, w, xi, yi;
m = perspective->matrix;
/* Matrix multiplication */
xp = (m[0] * x + m[1] * y + m[2]);
yp = (m[3] * x + m[4] * y + m[5]);
w = (m[6] * x + m[7] * y + m[8]);
/* Perspective division */
xi = xp / w;
yi = yp / w;
/* return values to caller */
*in_x = xi;
*in_y = yi;
GST_DEBUG_OBJECT (perspective, "Inversely mapped %d %d into %lf %lf",
x, y, *in_x, *in_y);
return TRUE;
}
static void
gst_perspective_class_init (GstPerspectiveClass * 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,
"perspective",
"Transform/Effect/Video",
"Apply a 2D perspective transform",
"Antonio Ospite <ospite@studenti.unina.it>");
gobject_class->set_property = gst_perspective_set_property;
gobject_class->get_property = gst_perspective_get_property;
g_object_class_install_property (gobject_class, PROP_MATRIX,
g_param_spec_value_array ("matrix",
"Matrix",
"Matrix of dimension 3x3 to use in the 2D transform, passed as an array of 9 elements in row-major order",
g_param_spec_double ("Element",
"Transformation matrix element",
"Element of the transformation matrix",
-G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS),
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
gstgt_class->map_func = perspective_map;
}
static void
gst_perspective_init (GstPerspective * filter)
{
/* set the Identity matrix as default */
filter->matrix[0] = 1;
filter->matrix[1] = 0;
filter->matrix[2] = 0;
filter->matrix[3] = 0;
filter->matrix[4] = 1;
filter->matrix[5] = 0;
filter->matrix[6] = 0;
filter->matrix[7] = 0;
filter->matrix[8] = 1;
}