+/* GStreamer
+ * Copyright (C) <2011> Jon Nordby <jononor@gmail.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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * SECTION:element-cairooverlay
+ *
+ * cairooverlay renders an overlay using a application provided render function.
+ *
+ * The full example can be found in tests/examples/cairo/cairo_overlay.c
+ * <refsect2>
+ * <title>Example code</title>
+ * |[
+ *
+ * #include <gst/gst.h>
+ * #include <gst/video/video.h>
+ *
+ * ...
+ *
+ * typedef struct {
+ * gboolean valid;
+ * int width;
+ * int height;
+ * } CairoOverlayState;
+ *
+ * ...
+ *
+ * static void
+ * prepare_overlay (GstElement * overlay, GstCaps * caps, gpointer user_data)
+ * {
+ * CairoOverlayState *state = (CairoOverlayState *)user_data;
+ *
+ * gst_video_format_parse_caps (caps, NULL, &state->width, &state->height);
+ * state->valid = TRUE;
+ * }
+ *
+ * static void
+ * draw_overlay (GstElement * overlay, cairo_t * cr, guint64 timestamp,
+ * guint64 duration, gpointer user_data)
+ * {
+ * CairoOverlayState *s = (CairoOverlayState *)user_data;
+ * double scale;
+ *
+ * if (!s->valid)
+ * return;
+ *
+ * scale = 2*(((timestamp/(int)1e7) % 70)+30)/100.0;
+ * cairo_translate(cr, s->width/2, (s->height/2)-30);
+ * cairo_scale (cr, scale, scale);
+ *
+ * cairo_move_to (cr, 0, 0);
+ * cairo_curve_to (cr, 0,-30, -50,-30, -50,0);
+ * cairo_curve_to (cr, -50,30, 0,35, 0,60 );
+ * cairo_curve_to (cr, 0,35, 50,30, 50,0 ); *
+ * cairo_curve_to (cr, 50,-30, 0,-30, 0,0 );
+ * cairo_set_source_rgba (cr, 0.9, 0.0, 0.1, 0.7);
+ * cairo_fill (cr);
+ * }
+ *
+ * ...
+ *
+ * cairo_overlay = gst_element_factory_make ("cairooverlay", "overlay");
+ *
+ * g_signal_connect (cairo_overlay, "draw", G_CALLBACK (draw_overlay),
+ * overlay_state);
+ * g_signal_connect (cairo_overlay, "caps-changed",
+ * G_CALLBACK (prepare_overlay), overlay_state);
+ * ...
+ *
+ * ]|
+ * </refsect2>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gstcairooverlay.h"
+#include "gstcairo-marshal.h"
+
+#include <gst/video/video.h>
+
+#include <cairo.h>
+
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+#define ARGB_CAPS GST_VIDEO_CAPS_BGRx " ; " GST_VIDEO_CAPS_BGRA " ; "
+#else
+#define ARGB_CAPS GST_VIDEO_CAPS_xRGB " ; " GST_VIDEO_CAPS_ARGB " ; "
+
+#endif
+
+static GstStaticPadTemplate gst_cairo_overlay_src_template =
+GST_STATIC_PAD_TEMPLATE ("src",
+ GST_PAD_SRC,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS (ARGB_CAPS)
+ );
+
+static GstStaticPadTemplate gst_cairo_overlay_sink_template =
+GST_STATIC_PAD_TEMPLATE ("sink",
+ GST_PAD_SINK,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS (ARGB_CAPS)
+ );
+
+
+GST_BOILERPLATE (GstCairoOverlay, gst_cairo_overlay, GstVideoFilter,
+ GST_TYPE_VIDEO_FILTER);
+
+enum
+{
+ SIGNAL_DRAW,
+ SIGNAL_CAPS_CHANGED,
+ N_SIGNALS
+};
+static guint gst_cairo_overlay_signals[N_SIGNALS];
+
+static gboolean
+gst_cairo_overlay_set_caps (GstBaseTransform * btrans, GstCaps * incaps,
+ GstCaps * outcaps)
+{
+ GstCairoOverlay *overlay = GST_CAIRO_OVERLAY (btrans);
+ GstStructure *s = gst_caps_get_structure (incaps, 0);
+
+ if (!gst_structure_get_int (s, "bpp", &(overlay->bpp))) {
+ return FALSE;
+ }
+
+ g_signal_emit (overlay, gst_cairo_overlay_signals[SIGNAL_CAPS_CHANGED], 0,
+ incaps, NULL);
+
+ return G_LIKELY (gst_video_format_parse_caps (incaps,
+ &overlay->caps_format, &overlay->caps_width, &overlay->caps_height));
+}
+
+static GstFlowReturn
+gst_cairo_overlay_transform_ip (GstBaseTransform * btrans, GstBuffer * buf)
+{
+
+ GstCairoOverlay *overlay = GST_CAIRO_OVERLAY (btrans);
+ cairo_surface_t *surface;
+ cairo_t *cr;
+ cairo_format_t format;
+
+ format = (overlay->bpp == 32) ? CAIRO_FORMAT_ARGB32 : CAIRO_FORMAT_RGB24;
+
+ surface =
+ cairo_image_surface_create_for_data (GST_BUFFER_DATA (buf), format,
+ 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;
+ }
+
+ g_signal_emit (overlay, gst_cairo_overlay_signals[SIGNAL_DRAW], 0,
+ cr, GST_BUFFER_TIMESTAMP (buf), GST_BUFFER_DURATION (buf), NULL);
+
+ cairo_destroy (cr);
+ cairo_surface_destroy (surface);
+ return GST_FLOW_OK;
+}
+
+static void
+gst_cairo_overlay_base_init (gpointer g_class)
+{
+ GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+ gst_element_class_set_details_simple (element_class, "Cairo overlay",
+ "Filter/Editor/Video",
+ "Render overlay on a video stream using Cairo",
+ "Jon Nordby <jononor@gmail.com>");
+
+ gst_element_class_add_pad_template (element_class,
+ gst_static_pad_template_get (&gst_cairo_overlay_sink_template));
+ gst_element_class_add_pad_template (element_class,
+ gst_static_pad_template_get (&gst_cairo_overlay_src_template));
+}
+
+static void
+gst_cairo_overlay_class_init (GstCairoOverlayClass * klass)
+{
+ GstBaseTransformClass *trans_class;
+
+ trans_class = (GstBaseTransformClass *) klass;
+
+ trans_class->set_caps = gst_cairo_overlay_set_caps;
+ trans_class->transform_ip = gst_cairo_overlay_transform_ip;
+
+ /**
+ * GstCairoOverlay::draw:
+ * @overlay: Overlay element emitting the signal.
+ * @cr: Cairo context to draw to.
+ * @timestamp: Timestamp (see GstClockTime) of the current buffer.
+ * @duration: Duration (see GstClockTime) of the current buffer.
+ *
+ * This signal is emitted when the overlay should be drawn.
+ */
+ gst_cairo_overlay_signals[SIGNAL_DRAW] =
+ g_signal_new ("draw",
+ G_TYPE_FROM_CLASS (klass),
+ 0,
+ 0,
+ NULL,
+ NULL,
+ gst_cairo_marshal_VOID__BOXED_UINT64_UINT64,
+ G_TYPE_NONE, 3, CAIRO_GOBJECT_TYPE_CONTEXT, G_TYPE_UINT64, G_TYPE_UINT64);
+
+ /**
+ * GstCairoOverlay::caps-changed:
+ * @overlay: Overlay element emitting the signal.
+ * @caps: The caps of the element.
+ *
+ * This signal is emitted when the caps of the element has changed.
+ */
+ gst_cairo_overlay_signals[SIGNAL_CAPS_CHANGED] =
+ g_signal_new ("caps-changed",
+ G_TYPE_FROM_CLASS (klass),
+ 0,
+ 0,
+ NULL, NULL, gst_cairo_marshal_VOID__BOXED, G_TYPE_NONE, 1, GST_TYPE_CAPS);
+}
+
+static void
+gst_cairo_overlay_init (GstCairoOverlay * overlay, GstCairoOverlayClass * klass)
+{
+}