videoaggregator: Create a new GstVideoAggregator baseclass

This base class has been added to a newly created libgstbadvideo library

Co-Authored by: Thibault Saunier <tsaunier@gnome.org>

https://bugzilla.gnome.org/show_bug.cgi?id=731918

gst-libs/gst/video/gstvideoaggregator.h

+/* Generic video aggregator plugin
+ * Copyright (C) 2008 Wim Taymans <wim@fluendo.com>
+ * Copyright (C) 2010 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * 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.
+ */
+ 
+#ifndef __GST_VIDEO_AGGREGATOR_H__
+#define __GST_VIDEO_AGGREGATOR_H__
+
+#include <gst/gst.h>
+#include <gst/video/video.h>
+#include <gst/base/gstaggregator.h>
+
+#include "gstvideoaggregatorpad.h"
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_VIDEO_AGGREGATOR (gst_videoaggregator_get_type())
+#define GST_VIDEO_AGGREGATOR(obj) \
+        (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_VIDEO_AGGREGATOR, GstVideoAggregator))
+#define GST_VIDEO_AGGREGATOR_CLASS(klass) \
+        (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_VIDEO_AGGREGATOR, GstVideoAggregatorClass))
+#define GST_IS_VIDEO_AGGREGATOR(obj) \
+        (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_VIDEO_AGGREGATOR))
+#define GST_IS_VIDEO_AGGREGATOR_CLASS(klass) \
+        (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_VIDEO_AGGREGATOR))
+#define GST_VIDEO_AGGREGATOR_GET_CLASS(obj) \
+        (G_TYPE_INSTANCE_GET_CLASS((obj),GST_TYPE_VIDEO_AGGREGATOR,GstVideoAggregatorClass))
+
+typedef struct _GstVideoAggregator GstVideoAggregator;
+typedef struct _GstVideoAggregatorClass GstVideoAggregatorClass;
+typedef struct _GstVideoAggregatorPrivate GstVideoAggregatorPrivate;
+
+/**
+ * GstVideoAggregator:
+ * @info: The #GstVideoInfo representing the currently set
+ * srcpad caps.
+ */
+struct _GstVideoAggregator
+{
+  GstAggregator aggregator;
+
+  /*< public >*/
+  /* Output caps */
+  GstVideoInfo info;
+
+  /* < private > */
+  GstVideoAggregatorPrivate *priv;
+  gpointer          _gst_reserved[GST_PADDING];
+};
+
+/**
+ * GstVideoAggregatorClass:
+ * @disable_frame_conversion: Optional.
+ *                            Allows subclasses to disable the frame colorspace
+ *                            conversion feature
+ * @update_info:              Optional.
+ *                            Lets subclasses update the src #GstVideoInfo representing
+ *                            the src pad caps before usage.
+ * @aggregate_frames:         Lets subclasses aggregate frames that are ready. Subclasses
+ *                            should iterate the GstElement.sinkpads and use the already
+ *                            mapped #GstVideoFrame from GstVideoAggregatorPad.aggregated_frame
+ *                            or directly use the #GstBuffer from GstVideoAggregatorPad.buffer
+ *                            if it needs to map the buffer in a special way. The result of the
+ *                            aggregation should land in @outbuffer.
+ * @get_output_buffer:        Optional.
+ *                            Lets subclasses provide a #GstBuffer to be used as @outbuffer of
+ *                            the #aggregate_frames vmethod.
+ * @negotiated_caps:          Optional.
+ *                            Notifies subclasses what caps format has been negotiated
+ **/
+struct _GstVideoAggregatorClass
+{
+  /*< private >*/
+  GstAggregatorClass parent_class;
+
+  /*< public >*/
+  gboolean           disable_frame_conversion;
+
+  gboolean           (*update_info)               (GstVideoAggregator *  videoaggregator,
+                                                   GstVideoInfo       *  info);
+  GstFlowReturn      (*aggregate_frames)          (GstVideoAggregator *  videoaggregator,
+                                                   GstBuffer          *  outbuffer);
+  GstFlowReturn      (*get_output_buffer)         (GstVideoAggregator *  videoaggregator,
+                                                   GstBuffer          ** outbuffer);
+  gboolean           (*negotiated_caps)           (GstVideoAggregator *  videoaggregator,
+                                                   GstCaps            *  caps);
+  /* < private > */
+  gpointer            _gst_reserved[GST_PADDING];
+};
+
+GType gst_videoaggregator_get_type       (void);
+
+G_END_DECLS
+#endif /* __GST_VIDEO_AGGREGATOR_H__ */