gstreamer/gst-libs/gst/wayland/wayland.c

/*
 * GStreamer Wayland Library
 * Copyright (C) 2014 Collabora Ltd.
 *
 * 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.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <gst/wayland/wayland.h>
#include <gst/video/videooverlay.h>

G_DEFINE_INTERFACE (GstWaylandVideo, gst_wayland_video, GST_TYPE_VIDEO_OVERLAY);

static void
gst_wayland_video_default_init (GstWaylandVideoInterface * klass)
{
  (void) klass;
}

/**
 * gst_wayland_video_set_surface_size:
 *
 * This tells the video sink to change the size of its drawing
 * surface. The caller must call gst_wayland_video_pause_rendering
 * before calling this method and gst_wayland_video_resume_rendering
 * later, on the next redraw request.
 */
void
gst_wayland_video_set_surface_size (GstWaylandVideo * video, gint w, gint h)
{
  GstWaylandVideoInterface *iface;

  g_return_if_fail (video != NULL);
  g_return_if_fail (GST_IS_WAYLAND_VIDEO (video));

  iface = GST_WAYLAND_VIDEO_GET_INTERFACE (video);

  if (iface->set_surface_size) {
    iface->set_surface_size (video, w, h);
  }
}

/**
 * gst_wayland_video_pause_rendering:
 *
 * This tells the video sink to stop rendering on the surface,
 * dropping frames in the meanwhile. This should be called
 * before resizing a stack of subsurfaces, one of which is
 * the surface of the video sink.
 */
void
gst_wayland_video_pause_rendering (GstWaylandVideo * video)
{
  GstWaylandVideoInterface *iface;

  g_return_if_fail (video != NULL);
  g_return_if_fail (GST_IS_WAYLAND_VIDEO (video));

  iface = GST_WAYLAND_VIDEO_GET_INTERFACE (video);

  if (iface->pause_rendering) {
    iface->pause_rendering (video);
  }
}

/**
 * gst_wayland_video_resume_rendering:
 *
 * Resumes surface rendering that was previously paused
 * with gst_wayland_video_pause_rendering. This function will
 * block until there is a new wl_buffer commited on the surface
 * inside the element, either with a new frame (if the element
 * is PLAYING) or with an old frame (if the element is PAUSED).
 */
void
gst_wayland_video_resume_rendering (GstWaylandVideo * video)
{
  GstWaylandVideoInterface *iface;

  g_return_if_fail (video != NULL);
  g_return_if_fail (GST_IS_WAYLAND_VIDEO (video));

  iface = GST_WAYLAND_VIDEO_GET_INTERFACE (video);

  if (iface->resume_rendering) {
    iface->resume_rendering (video);
  }
}