gstreamer/gst/camerabin2/gstdigitalzoom.c

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/*
* GStreamer
* Copyright (C) 2015 Thiago Santos <thiagoss@osg.samsung.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.
*/
/**
* SECTION:element-digitalzoom
*
* Does digital zooming by cropping and scaling an image.
*
* It is a bin that contains the internal pipeline:
* videocrop ! videoscale ! capsfilter
*
* It keeps monitoring the input caps and when it is set/updated
* the capsfilter gets set the same caps to guarantee that the same
* input resolution is provided as output.
*
* Exposes the 'zoom' property as a float to allow setting the amount
* of zoom desired. Zooming is done in the center.
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <gst/gst-i18n-plugin.h>
#include "gstdigitalzoom.h"
enum
{
PROP_0,
PROP_ZOOM
};
GST_DEBUG_CATEGORY (digital_zoom_debug);
#define GST_CAT_DEFAULT digital_zoom_debug
#define gst_digital_zoom_parent_class parent_class
G_DEFINE_TYPE (GstDigitalZoom, gst_digital_zoom, GST_TYPE_BIN);
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static void
gst_digital_zoom_update_crop (GstDigitalZoom * self, GstCaps * caps)
{
gint w2_crop = 0, h2_crop = 0;
gint left = 0;
gint right = 0;
gint top = 0;
gint bottom = 0;
gint width, height;
gfloat zoom;
GstStructure *structure;
if (caps == NULL || gst_caps_is_any (caps)) {
g_object_set (self->capsfilter, "caps", NULL, NULL);
return;
}
structure = gst_caps_get_structure (caps, 0);
gst_structure_get (structure, "width", G_TYPE_INT, &width, "height",
G_TYPE_INT, &height, NULL);
zoom = self->zoom;
if (self->videocrop) {
/* Update capsfilters to apply the zoom */
GST_INFO_OBJECT (self, "zoom: %f, orig size: %dx%d", zoom, width, height);
if (zoom != 1.0) {
w2_crop = (width - (gint) (width * 1.0 / zoom)) / 2;
h2_crop = (height - (gint) (height * 1.0 / zoom)) / 2;
left += w2_crop;
right += w2_crop;
top += h2_crop;
bottom += h2_crop;
/* force number of pixels cropped from left to be even, to avoid slow code
* path on videoscale */
left &= 0xFFFE;
}
GST_INFO_OBJECT (self,
"sw cropping: left:%d, right:%d, top:%d, bottom:%d", left, right, top,
bottom);
g_object_set (self->videocrop, "left", left, "right", right, "top",
top, "bottom", bottom, NULL);
}
}
static void
gst_digital_zoom_update_zoom (GstDigitalZoom * self)
{
GstCaps *caps = NULL;
if (!self->elements_created)
return;
g_object_get (self->capsfilter, "caps", &caps, NULL);
if (caps) {
gst_digital_zoom_update_crop (self, caps);
gst_caps_unref (caps);
}
}
static void
gst_digital_zoom_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec)
{
GstDigitalZoom *self = GST_DIGITAL_ZOOM_CAST (object);
switch (prop_id) {
case PROP_ZOOM:
self->zoom = g_value_get_float (value);
GST_DEBUG_OBJECT (self, "Setting zoom: %f", self->zoom);
gst_digital_zoom_update_zoom (self);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (self, prop_id, pspec);
break;
}
}
static void
gst_digital_zoom_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec)
{
GstDigitalZoom *self = GST_DIGITAL_ZOOM_CAST (object);
switch (prop_id) {
case PROP_ZOOM:
g_value_set_float (value, self->zoom);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (self, prop_id, pspec);
break;
}
}
static gboolean
gst_digital_zoom_sink_query (GstPad * sink, GstObject * parent,
GstQuery * query)
{
GstDigitalZoom *self = GST_DIGITAL_ZOOM_CAST (parent);
switch (GST_QUERY_TYPE (query)) {
/* for caps related queries we want to skip videocrop ! videoscale
* as the digital zoom preserves input dimensions */
case GST_QUERY_CAPS:
case GST_QUERY_ACCEPT_CAPS:
if (self->elements_created)
return gst_pad_peer_query (self->srcpad, query);
/* fall through */
default:
return gst_pad_query_default (sink, parent, query);
}
}
static gboolean
gst_digital_zoom_src_query (GstPad * sink, GstObject * parent, GstQuery * query)
{
GstDigitalZoom *self = GST_DIGITAL_ZOOM_CAST (parent);
switch (GST_QUERY_TYPE (query)) {
/* for caps related queries we want to skip videocrop ! videoscale
* as the digital zoom preserves input dimensions */
case GST_QUERY_CAPS:
case GST_QUERY_ACCEPT_CAPS:
if (self->elements_created)
return gst_pad_peer_query (self->sinkpad, query);
/* fall through */
default:
return gst_pad_query_default (sink, parent, query);
}
}
static gboolean
gst_digital_zoom_sink_event (GstPad * sink, GstObject * parent,
GstEvent * event)
{
gboolean ret;
gboolean is_caps;
GstDigitalZoom *self = GST_DIGITAL_ZOOM_CAST (parent);
GstCaps *old_caps = NULL;
GstCaps *caps = NULL;
is_caps = GST_EVENT_TYPE (event) == GST_EVENT_CAPS;
if (is_caps) {
gst_event_parse_caps (event, &caps);
g_object_get (self->capsfilter, "caps", &old_caps, NULL);
g_object_set (self->capsfilter, "caps", caps, NULL);
gst_digital_zoom_update_crop (self, caps);
}
ret = gst_pad_event_default (sink, parent, event);
if (is_caps) {
if (!ret) {
gst_digital_zoom_update_crop (self, old_caps);
g_object_set (self->capsfilter, "caps", old_caps, NULL);
}
if (old_caps)
gst_caps_unref (old_caps);
}
return ret;
}
static void
gst_digital_zoom_dispose (GObject * object)
{
GstDigitalZoom *self = GST_DIGITAL_ZOOM_CAST (object);
if (self->capsfilter_sinkpad) {
gst_object_unref (self->capsfilter_sinkpad);
self->capsfilter_sinkpad = NULL;
}
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
gst_digital_zoom_init (GstDigitalZoom * self)
{
GstPadTemplate *tmpl;
tmpl = gst_static_pad_template_get (&src_template);
self->srcpad = gst_ghost_pad_new_no_target_from_template ("src", tmpl);
gst_element_add_pad (GST_ELEMENT (self), self->srcpad);
gst_object_unref (tmpl);
tmpl = gst_static_pad_template_get (&sink_template);
self->sinkpad = gst_ghost_pad_new_no_target_from_template ("sink", tmpl);
gst_element_add_pad (GST_ELEMENT (self), self->sinkpad);
gst_object_unref (tmpl);
gst_pad_set_event_function (self->sinkpad,
GST_DEBUG_FUNCPTR (gst_digital_zoom_sink_event));
gst_pad_set_query_function (self->sinkpad,
GST_DEBUG_FUNCPTR (gst_digital_zoom_sink_query));
gst_pad_set_query_function (self->srcpad,
GST_DEBUG_FUNCPTR (gst_digital_zoom_src_query));
self->zoom = 1;
}
static GstElement *
zoom_create_element (GstDigitalZoom * self, const gchar * element_name,
const gchar * name)
{
GstElement *element;
element = gst_element_factory_make (element_name, name);
if (element == NULL) {
GST_ELEMENT_ERROR (self, CORE, MISSING_PLUGIN,
(_("Missing element '%s' - check your GStreamer installation."),
element_name), (NULL));
}
return element;
}
static gboolean
gst_digital_zoom_create_elements (GstDigitalZoom * self)
{
GstPad *pad;
if (self->elements_created)
return TRUE;
self->videocrop = zoom_create_element (self, "videocrop", "zoom-videocrop");
if (self->videocrop == NULL)
return FALSE;
if (!gst_bin_add (GST_BIN_CAST (self), self->videocrop))
return FALSE;
self->videoscale =
zoom_create_element (self, "videoscale", "zoom-videoscale");
if (self->videoscale == NULL)
return FALSE;
if (!gst_bin_add (GST_BIN_CAST (self), self->videoscale))
return FALSE;
self->capsfilter =
zoom_create_element (self, "capsfilter", "zoom-capsfilter");
if (self->capsfilter == NULL)
return FALSE;
if (!gst_bin_add (GST_BIN_CAST (self), self->capsfilter))
return FALSE;
if (!gst_element_link_pads_full (self->videocrop, "src", self->videoscale,
"sink", GST_PAD_LINK_CHECK_CAPS))
return FALSE;
if (!gst_element_link_pads_full (self->videoscale, "src", self->capsfilter,
"sink", GST_PAD_LINK_CHECK_CAPS))
return FALSE;
pad = gst_element_get_static_pad (self->videocrop, "sink");
gst_ghost_pad_set_target (GST_GHOST_PAD (self->sinkpad), pad);
gst_object_unref (pad);
pad = gst_element_get_static_pad (self->capsfilter, "src");
gst_ghost_pad_set_target (GST_GHOST_PAD (self->srcpad), pad);
gst_object_unref (pad);
self->capsfilter_sinkpad =
gst_element_get_static_pad (self->capsfilter, "sink");
self->elements_created = TRUE;
return TRUE;
}
static GstStateChangeReturn
gst_digital_zoom_change_state (GstElement * element, GstStateChange trans)
{
GstDigitalZoom *self = GST_DIGITAL_ZOOM_CAST (element);
switch (trans) {
case GST_STATE_CHANGE_NULL_TO_READY:
if (!gst_digital_zoom_create_elements (self)) {
return GST_STATE_CHANGE_FAILURE;
}
break;
default:
break;
}
return GST_ELEMENT_CLASS (parent_class)->change_state (element, trans);
}
static void
gst_digital_zoom_class_init (GstDigitalZoomClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = G_OBJECT_CLASS (klass);
gstelement_class = GST_ELEMENT_CLASS (klass);
gobject_class->dispose = gst_digital_zoom_dispose;
gobject_class->set_property = gst_digital_zoom_set_property;
gobject_class->get_property = gst_digital_zoom_get_property;
/* g_object_class_install_property .... */
g_object_class_install_property (gobject_class, PROP_ZOOM,
g_param_spec_float ("zoom", "Zoom",
"Digital zoom level to be used", 1.0, G_MAXFLOAT, 1.0,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
gstelement_class->change_state = gst_digital_zoom_change_state;
GST_DEBUG_CATEGORY_INIT (digital_zoom_debug, "digitalzoom",
0, "digital zoom");
gst_element_class_add_static_pad_template (gstelement_class, &sink_template);
gst_element_class_add_static_pad_template (gstelement_class, &src_template);
gst_element_class_set_static_metadata (gstelement_class,
"Digital zoom bin", "Generic/Video",
"Digital zoom bin", "Thiago Santos <thiagoss@osg.samsung.com>");
}