| /* 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 TEMPLATE_CAPS GST_VIDEO_CAPS_BGRx " ; " GST_VIDEO_CAPS_BGRA " ; " |
| #else |
| #define TEMPLATE_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 (TEMPLATE_CAPS) |
| ); |
| |
| static GstStaticPadTemplate gst_cairo_overlay_sink_template = |
| GST_STATIC_PAD_TEMPLATE ("sink", |
| GST_PAD_SINK, |
| GST_PAD_ALWAYS, |
| GST_STATIC_CAPS (TEMPLATE_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); |
| gboolean ret; |
| |
| ret = |
| gst_video_format_parse_caps (incaps, &overlay->format, &overlay->width, |
| &overlay->height); |
| if (G_UNLIKELY (!ret)) |
| return FALSE; |
| |
| g_signal_emit (overlay, gst_cairo_overlay_signals[SIGNAL_CAPS_CHANGED], 0, |
| incaps, NULL); |
| |
| return ret; |
| } |
| |
| 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->format == GST_VIDEO_FORMAT_ARGB |
| || overlay->format == GST_VIDEO_FORMAT_BGRA) ? |
| CAIRO_FORMAT_ARGB32 : CAIRO_FORMAT_RGB24; |
| |
| surface = |
| cairo_image_surface_create_for_data (GST_BUFFER_DATA (buf), format, |
| overlay->width, overlay->height, overlay->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_static_metadata (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 #GstCaps 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) |
| { |
| } |