gstreamer/ext/rsvg/gstrsvgoverlay.c
Olivier Aubert c86b12ac95 rsvgoverlay: scalable and relative svg overlay with cairo
Add a cairo+librsvg based overlay element to the rsvg plugin.
2010-11-22 17:08:06 +02:00

394 lines
12 KiB
C

/* GStreamer
* Copyright (C) 2010 Olivier Aubert <olivier.aubert@liris.cnrs.fr>
*
* 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.
*/
/**
* SECTION:element-rsvgoverlay
*
* This elements overlays SVG graphics over the video. SVG data can
* either be specified through properties, or fed through the
* data-sink pad.
*
* Note: setting the x or y parameter to a non-zero value will implicitly disable the fit-to-frame behaviour.
*
* <refsect2>
*
* <title>Example launch lines</title>
* |[
* gst-launch -v videotestsrc ! ffmpegcolorspace ! rsvgoverlay location=foo.svg ! ffmpegcolorspace ! autovideosink
* ]| specifies the SVG location through the filename property.
* |[
* gst-launch -v videotestsrc ! ffmpegcolorspace ! rsvgoverlay name=overlay ! ffmpegcolorspace ! autovideosink filesrc location=foo.svg ! image/svg ! overlay.data_sink
* ]| does the same by feeding data through the data_sink pad. You can also specify the SVG data itself as parameter:
* |[
* gst-launch -v videotestsrc ! ffmpegcolorspace ! rsvgoverlay data='<svg viewBox="0 0 800 600"><image x="80%" y="80%" width="10%" height="10%" xlink:href="foo.jpg" /></svg>' ! ffmpegcolorspace ! autovideosink
* ]|
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "gstrsvgoverlay.h"
#include <string.h>
#include <gst/video/video.h>
#include <librsvg/rsvg.h>
#include <librsvg/rsvg-cairo.h>
enum
{
PROP_0,
PROP_DATA,
PROP_FILENAME,
PROP_FIT_TO_FRAME,
PROP_X,
PROP_Y,
};
#define GST_RSVG_LOCK(overlay) G_STMT_START { \
GST_LOG_OBJECT (overlay, "Locking rsvgoverlay from thread %p", g_thread_self ()); \
g_static_mutex_lock (&overlay->rsvg_lock); \
GST_LOG_OBJECT (overlay, "Locked rsvgoverlay from thread %p", g_thread_self ()); \
} G_STMT_END
#define GST_RSVG_UNLOCK(overlay) G_STMT_START { \
GST_LOG_OBJECT (overlay, "Unlocking rsvgoverlay from thread %p", g_thread_self ()); \
g_static_mutex_unlock (&overlay->rsvg_lock); \
} G_STMT_END
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
#define GST_RSVG_VIDEO_CAPS GST_VIDEO_CAPS_BGRA
#else
#define GST_RSVG_VIDEO_CAPS GST_VIDEO_CAPS_ARGB
#endif
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS (GST_RSVG_VIDEO_CAPS)
);
static GstStaticPadTemplate video_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS (GST_RSVG_VIDEO_CAPS)
);
static GstStaticPadTemplate data_sink_template =
GST_STATIC_PAD_TEMPLATE ("data_sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("image/svg+xml; image/svg; text/plain"));
GST_BOILERPLATE (GstRsvgOverlay, gst_rsvg_overlay, GstVideoFilter,
GST_TYPE_VIDEO_FILTER);
static void
gst_rsvg_overlay_set_svg_data (GstRsvgOverlay * overlay, const gchar * data,
gboolean consider_as_filename)
{
GstBaseTransform *btrans = GST_BASE_TRANSFORM (overlay);
gsize size;
GError *error = NULL;
if (overlay->handle) {
g_object_unref (overlay->handle);
overlay->handle = NULL;
gst_base_transform_set_passthrough (btrans, TRUE);
}
/* data may be NULL */
if (data) {
size = strlen (data);
if (size) {
/* Read data either from string or from file */
if (consider_as_filename)
overlay->handle = rsvg_handle_new_from_file (data, &error);
else
overlay->handle =
rsvg_handle_new_from_data ((guint8 *) data, size, &error);
if (error) {
GST_ERROR_OBJECT (overlay, "Cannot read SVG data: %s\n%s",
error->message, data);
g_error_free (error);
} else {
/* Get SVG dimension. */
RsvgDimensionData svg_dimension;
rsvg_handle_get_dimensions (overlay->handle, &svg_dimension);
overlay->width = svg_dimension.width;
overlay->height = svg_dimension.height;
gst_base_transform_set_passthrough (btrans, FALSE);
}
}
}
}
static void
gst_rsvg_overlay_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstRsvgOverlay *overlay = GST_RSVG_OVERLAY (object);
GST_RSVG_LOCK (overlay);
switch (prop_id) {
case PROP_DATA:
{
gst_rsvg_overlay_set_svg_data (overlay, g_value_get_string (value),
FALSE);
break;
}
case PROP_FILENAME:
{
gst_rsvg_overlay_set_svg_data (overlay, g_value_get_string (value), TRUE);
break;
}
case PROP_FIT_TO_FRAME:
{
overlay->fit_to_frame = g_value_get_boolean (value);
break;
}
case PROP_X:
{
overlay->x_offset = g_value_get_int (value);
break;
}
case PROP_Y:
{
overlay->y_offset = g_value_get_int (value);
break;
}
default:
{
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
GST_RSVG_UNLOCK (overlay);
}
static void
gst_rsvg_overlay_get_property (GObject * object, guint prop_id, GValue * value,
GParamSpec * pspec)
{
GstRsvgOverlay *overlay = GST_RSVG_OVERLAY (object);
switch (prop_id) {
case PROP_X:
g_value_set_uint (value, overlay->x_offset);
break;
case PROP_Y:
g_value_set_uint (value, overlay->y_offset);
break;
case PROP_FIT_TO_FRAME:
g_value_set_boolean (value, overlay->fit_to_frame);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static GstFlowReturn
gst_rsvg_overlay_data_sink_chain (GstPad * pad, GstBuffer * buffer)
{
GstRsvgOverlay *overlay = GST_RSVG_OVERLAY (GST_PAD_PARENT (pad));
gst_adapter_push (overlay->adapter, buffer);
return GST_FLOW_OK;
}
static gboolean
gst_rsvg_overlay_data_sink_event (GstPad * pad, GstEvent * event)
{
GstRsvgOverlay *overlay = GST_RSVG_OVERLAY (GST_PAD_PARENT (pad));
GST_LOG_OBJECT (pad, "Got %s event", GST_EVENT_TYPE_NAME (event));
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_EOS:{
guint data_size;
GST_RSVG_LOCK (overlay);
/* FIXME: rsvgdec looks for </svg> in data to determine the end
of SVG code. Should we really do the same here? IOW, could
data be sent and _pushed() before the EOS gets processed? */
data_size = gst_adapter_available (overlay->adapter);
if (data_size) {
gst_rsvg_overlay_set_svg_data (overlay,
(const gchar *) gst_adapter_take (overlay->adapter, data_size),
FALSE);
gst_adapter_clear (overlay->adapter);
}
GST_RSVG_UNLOCK (overlay);
}
case GST_EVENT_FLUSH_START:
gst_adapter_clear (overlay->adapter);
break;
default:
break;
}
/* Dropping all events here */
gst_event_unref (event);
return TRUE;
}
static gboolean
gst_rsvg_overlay_set_caps (GstBaseTransform * btrans, GstCaps * incaps,
GstCaps * outcaps)
{
GstRsvgOverlay *overlay = GST_RSVG_OVERLAY (btrans);
return G_LIKELY (gst_video_format_parse_caps (incaps,
&overlay->caps_format, &overlay->caps_width, &overlay->caps_height));
}
static GstFlowReturn
gst_rsvg_overlay_transform_ip (GstBaseTransform * btrans, GstBuffer * buf)
{
GstRsvgOverlay *overlay = GST_RSVG_OVERLAY (btrans);
cairo_surface_t *surface;
cairo_t *cr;
GST_RSVG_LOCK (overlay);
if (!overlay->handle) {
GST_RSVG_UNLOCK (overlay);
return GST_FLOW_OK;
}
surface =
cairo_image_surface_create_for_data (GST_BUFFER_DATA (buf),
CAIRO_FORMAT_ARGB32, overlay->caps_width, overlay->caps_height,
overlay->caps_width * 4);
if (G_UNLIKELY (!surface))
return GST_FLOW_ERROR;
cr = cairo_create (surface);
if (G_UNLIKELY (!cr)) {
cairo_surface_destroy (surface);
return GST_FLOW_ERROR;
}
/* If x or y offset is specified, do not fit-to-frame. */
if (overlay->x_offset || overlay->y_offset)
cairo_translate (cr, (double) overlay->x_offset,
(double) overlay->y_offset);
else if (overlay->fit_to_frame && overlay->width && overlay->height)
cairo_scale (cr, (float) overlay->caps_width / overlay->width,
(float) overlay->caps_height / overlay->height);
rsvg_handle_render_cairo (overlay->handle, cr);
GST_RSVG_UNLOCK (overlay);
cairo_destroy (cr);
cairo_surface_destroy (surface);
return GST_FLOW_OK;
}
static gboolean
gst_rsvg_overlay_stop (GstBaseTransform * btrans)
{
GstRsvgOverlay *overlay = GST_RSVG_OVERLAY (btrans);
if (overlay->handle) {
g_object_unref (overlay->handle);
g_object_unref (overlay->adapter);
overlay->handle = NULL;
}
return TRUE;
}
static void
gst_rsvg_overlay_base_init (gpointer klass)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&src_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&video_sink_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&data_sink_template));
gst_element_class_set_details_simple (element_class, "RSVG overlay",
"Filter/Editor/Video",
"Overlays SVG graphics over a video stream",
"Olivier Aubert <olivier.aubert@liris.cnrs.fr>");
}
static void
gst_rsvg_overlay_class_init (GstRsvgOverlayClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
GstBaseTransformClass *basetransform_class = GST_BASE_TRANSFORM_CLASS (klass);
gobject_class->set_property = gst_rsvg_overlay_set_property;
gobject_class->get_property = gst_rsvg_overlay_get_property;
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_DATA,
g_param_spec_string ("data", "data", "SVG data.", "",
G_PARAM_WRITABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_FILENAME,
g_param_spec_string ("location", "location", "SVG file location.", "",
G_PARAM_WRITABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_FIT_TO_FRAME,
g_param_spec_boolean ("fit-to-frame", "fit to frame",
"Fit the SVG to fill the whole frame.", TRUE,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_X,
g_param_spec_int ("x", "x offset",
"Specify an x offset.", 0, G_MAXINT, 0,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_Y,
g_param_spec_int ("y", "y offset",
"Specify a y offset.", 0, G_MAXINT, 0,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
basetransform_class->set_caps = gst_rsvg_overlay_set_caps;
basetransform_class->transform_ip = gst_rsvg_overlay_transform_ip;
basetransform_class->stop = gst_rsvg_overlay_stop;
basetransform_class->passthrough_on_same_caps = FALSE;
}
static void
gst_rsvg_overlay_init (GstRsvgOverlay * overlay, GstRsvgOverlayClass * klass)
{
overlay->fit_to_frame = 1;
overlay->adapter = gst_adapter_new ();
/* data sink */
overlay->data_sinkpad =
gst_pad_new_from_static_template (&data_sink_template, "data_sink");
gst_pad_set_chain_function (overlay->data_sinkpad,
GST_DEBUG_FUNCPTR (gst_rsvg_overlay_data_sink_chain));
gst_pad_set_event_function (overlay->data_sinkpad,
GST_DEBUG_FUNCPTR (gst_rsvg_overlay_data_sink_event));
gst_element_add_pad (GST_ELEMENT (overlay), overlay->data_sinkpad);
}