video: add GstVideoSinkClass::show_frame()

Add ::show_frame() vfunc which maps to basesink's ::preroll and ::render
vfuncs and add some gtk-doc chunks.

API: GstVideoSinkClass::show_frame()

gst-libs/gst/video/gstvideosink.c

@@ -1,7 +1,6 @@
-/*
+/*  GStreamer video sink base class
- *  GStreamer Video sink.
- *
  *  Copyright (C) <2003> Julien Moutte <julien@moutte.net>
+ *  Copyright (C) <2009> Tim-Philipp Müller <tim centricular net>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -44,7 +43,12 @@
 GST_DEBUG_CATEGORY_STATIC (video_sink_debug);
 #define GST_CAT_DEFAULT video_sink_debug
 
-static GstElementClass *parent_class = NULL;
+static GstBaseSinkClass *parent_class = NULL;
+
+static GstFlowReturn gst_video_sink_show_preroll_frame (GstBaseSink * bsink,
+    GstBuffer * buf);
+static GstFlowReturn gst_video_sink_show_frame (GstBaseSink * bsink,
+    GstBuffer * buf);
 
 /**
  * gst_video_sink_center_rect:
@@ -112,7 +116,13 @@ gst_video_sink_init (GstVideoSink * videosink)
 static void
 gst_video_sink_class_init (GstVideoSinkClass * klass)
 {
+  GstBaseSinkClass *basesink_class = (GstBaseSinkClass *) klass;
+
   parent_class = g_type_class_peek_parent (klass);
+
+  basesink_class->render = GST_DEBUG_FUNCPTR (gst_video_sink_show_frame);
+  basesink_class->preroll =
+      GST_DEBUG_FUNCPTR (gst_video_sink_show_preroll_frame);
 }
 
 static void
@@ -121,6 +131,46 @@ gst_video_sink_base_init (gpointer g_class)
   GST_DEBUG_CATEGORY_INIT (video_sink_debug, "videosink", 0, "GstVideoSink");
 }
 
+static GstFlowReturn
+gst_video_sink_show_preroll_frame (GstBaseSink * bsink, GstBuffer * buf)
+{
+  GstVideoSinkClass *klass;
+
+  klass = GST_VIDEO_SINK_GET_CLASS (bsink);
+
+  if (klass->show_frame == NULL) {
+    if (parent_class->preroll != NULL)
+      return parent_class->preroll (bsink, buf);
+    else
+      return GST_FLOW_OK;
+  }
+
+  GST_LOG_OBJECT (bsink, "rendering frame, ts=%" GST_TIME_FORMAT,
+      GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)));
+
+  return klass->show_frame (GST_VIDEO_SINK_CAST (bsink), buf);
+}
+
+static GstFlowReturn
+gst_video_sink_show_frame (GstBaseSink * bsink, GstBuffer * buf)
+{
+  GstVideoSinkClass *klass;
+
+  klass = GST_VIDEO_SINK_GET_CLASS (bsink);
+
+  if (klass->show_frame == NULL) {
+    if (parent_class->render != NULL)
+      return parent_class->render (bsink, buf);
+    else
+      return GST_FLOW_OK;
+  }
+
+  GST_LOG_OBJECT (bsink, "rendering frame, ts=%" GST_TIME_FORMAT,
+      GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)));
+
+  return klass->show_frame (GST_VIDEO_SINK_CAST (bsink), buf);
+}
+
 /* Public methods */
 
 GType

gst-libs/gst/video/gstvideosink.h

@@ -1,7 +1,6 @@
-/*
+/*  GStreamer video sink base class
- *  GStreamer Video sink.
- *
  *  Copyright (C) <2003> Julien Moutte <julien@moutte.net>
+ *  Copyright (C) <2009> Tim-Philipp Müller <tim centricular net>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -19,6 +18,8 @@
  * Boston, MA 02111-1307, USA.
  */
 
+/* FIXME 0.11: turn this into a proper base class */
+
 #ifndef __GST_VIDEO_SINK_H__
 #define __GST_VIDEO_SINK_H__
 
@@ -80,18 +81,40 @@ struct _GstVideoRectangle {
   gint h;
 };
 
+/**
+ * GstVideoSink:
+ * @element: the parent object structure (which is GstBaseSink)
+ * @height: video height (derived class needs to set this)
+ * @width: video width (derived class needs to set this)
+ *
+ * The video sink instance structure. Derived video sinks should set the
+ * @height and @width members.
+ */
 struct _GstVideoSink {
-  GstBaseSink element;
+  GstBaseSink element;    /* FIXME 0.11: this should not be called 'element' */
   
   gint width, height;
   
+  /*< private >*/
   gpointer _gst_reserved[GST_PADDING];
 };
 
+/**
+ * GstVideoSinkClass:
+ * @parent_class: the parent class structure
+ * @show_frame: render a video frame. Maps to #GstBaseSink::render and
+ *     #GstBaseSink::preroll vfuncs. Since: 0.10.25
+ *
+ * The video sink class structure. Derived classes should override the
+ * @show_frame virtual function.
+ */
 struct _GstVideoSinkClass {
   GstBaseSinkClass parent_class;
 
-  gpointer _gst_reserved[GST_PADDING];
+  GstFlowReturn  (*show_frame) (GstVideoSink *video_sink, GstBuffer *buf);
+
+  /*< private >*/
+  gpointer _gst_reserved[GST_PADDING - 1];
 };
 
 GType gst_video_sink_get_type (void);