gstreamer/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/video/video.h>
#include <gst/base/gstaggregator.h>

G_BEGIN_DECLS

typedef struct _GstVideoAggregator GstVideoAggregator;
typedef struct _GstVideoAggregatorClass GstVideoAggregatorClass;
typedef struct _GstVideoAggregatorPrivate GstVideoAggregatorPrivate;

/*************************
 * GstVideoAggregatorPad *
 *************************/

#define GST_TYPE_VIDEO_AGGREGATOR_PAD (gst_video_aggregator_pad_get_type())
#define GST_VIDEO_AGGREGATOR_PAD(obj) \
        (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_VIDEO_AGGREGATOR_PAD, GstVideoAggregatorPad))
#define GST_VIDEO_AGGREGATOR_PAD_CAST(obj) ((GstVideoAggregatorPad *)(obj))
#define GST_VIDEO_AGGREGATOR_PAD_CLASS(klass) \
        (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_VIDEO_AGGREGATOR_PAD, GstVideoAggregatorPadClass))
#define GST_IS_VIDEO_AGGREGATOR_PAD(obj) \
        (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_VIDEO_AGGREGATOR_PAD))
#define GST_IS_VIDEO_AGGREGATOR_PAD_CLASS(klass) \
        (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_VIDEO_AGGREGATOR_PAD))
#define GST_VIDEO_AGGREGATOR_PAD_GET_CLASS(obj) \
        (G_TYPE_INSTANCE_GET_CLASS((obj),GST_TYPE_VIDEO_AGGREGATOR_PAD,GstVideoAggregatorPadClass))

typedef struct _GstVideoAggregatorPad GstVideoAggregatorPad;
typedef struct _GstVideoAggregatorPadClass GstVideoAggregatorPadClass;
typedef struct _GstVideoAggregatorPadPrivate GstVideoAggregatorPadPrivate;

/**
 * GstVideoAggregatorPad:
 * @info: The #GstVideoInfo currently set on the pad
 */
struct _GstVideoAggregatorPad
{
  GstAggregatorPad              parent;

  /*< public >*/
  /* read-only, with OBJECT_LOCK */
  GstVideoInfo                  info;

  /* < private > */
  GstVideoAggregatorPadPrivate *priv;

  gpointer                     _gst_reserved[GST_PADDING];
};

/**
 * GstVideoAggregatorPadClass:
 * @update_conversion_info: Called when either the input or output formats
 *                          have changed.
 * @prepare_frame: Prepare the frame from the pad buffer and sets it to prepared_frame
 * @clean_frame:   clean the frame previously prepared in prepare_frame
 */
struct _GstVideoAggregatorPadClass
{
  GstAggregatorPadClass parent_class;
  void               (*update_conversion_info) (GstVideoAggregatorPad * pad);

  gboolean           (*prepare_frame)          (GstVideoAggregatorPad * pad,
                                                GstVideoAggregator    * videoaggregator,
                                                GstBuffer             * buffer,
                                                GstVideoFrame         * prepared_frame);

  void               (*clean_frame)            (GstVideoAggregatorPad * pad,
                                                GstVideoAggregator    * videoaggregator,
                                                GstVideoFrame         * prepared_frame);

  gpointer          _gst_reserved[GST_PADDING_LARGE];
};

GST_VIDEO_API
GType gst_video_aggregator_pad_get_type   (void);

GST_VIDEO_API
gboolean gst_video_aggregator_pad_has_current_buffer (GstVideoAggregatorPad *pad);

GST_VIDEO_API
GstBuffer * gst_video_aggregator_pad_get_current_buffer (GstVideoAggregatorPad *pad);

GST_VIDEO_API
GstVideoFrame * gst_video_aggregator_pad_get_prepared_frame (GstVideoAggregatorPad *pad);

GST_VIDEO_API
void gst_video_aggregator_pad_set_needs_alpha (GstVideoAggregatorPad *pad, gboolean needs_alpha);

/********************************
 * GstVideoAggregatorConvertPad *
 *******************************/

#define GST_TYPE_VIDEO_AGGREGATOR_CONVERT_PAD            (gst_video_aggregator_convert_pad_get_type())
#define GST_VIDEO_AGGREGATOR_CONVERT_PAD(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_VIDEO_AGGREGATOR_CONVERT_PAD, GstVideoAggregatorConvertPad))
#define GST_VIDEO_AGGREGATOR_CONVERT_PAD_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_VIDEO_AGGREGATOR_CONVERT_PAD, GstVideoAggregatorConvertPadClass))
#define GST_VIDEO_AGGREGATOR_CONVERT_PAD_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),GST_TYPE_VIDEO_AGGREGATOR_CONVERT_PAD, GstVideoAggregatorConvertPadClass))
#define GST_IS_VIDEO_AGGREGATOR_CONVERT_PAD(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_VIDEO_AGGREGATOR_CONVERT_PAD))
#define GST_IS_VIDEO_AGGREGATOR_CONVERT_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_VIDEO_AGGREGATOR_CONVERT_PAD))

typedef struct _GstVideoAggregatorConvertPad GstVideoAggregatorConvertPad;
typedef struct _GstVideoAggregatorConvertPadClass GstVideoAggregatorConvertPadClass;
typedef struct _GstVideoAggregatorConvertPadPrivate GstVideoAggregatorConvertPadPrivate;

/**
 * GstVideoAggregatorConvertPad:
 *
 * An implementation of GstPad that can be used with #GstVideoAggregator.
 *
 * See #GstVideoAggregator for more details.
 */
struct _GstVideoAggregatorConvertPad
{
  /*< private >*/
  GstVideoAggregatorPad                  parent;

  GstVideoAggregatorConvertPadPrivate   *priv;

  gpointer _gst_reserved[GST_PADDING];
};

/**
 * GstVideoAggregatorConvertPadClass:
 *
 */
struct _GstVideoAggregatorConvertPadClass
{
  GstVideoAggregatorPadClass   parent_class;

  void (*create_conversion_info) (GstVideoAggregatorConvertPad *pad, GstVideoAggregator *agg, GstVideoInfo *conversion_info);

  /*< private >*/
  gpointer      _gst_reserved[GST_PADDING];
};

GST_VIDEO_API
GType gst_video_aggregator_convert_pad_get_type           (void);

GST_VIDEO_API
void gst_video_aggregator_convert_pad_update_conversion_info (GstVideoAggregatorConvertPad * pad);

/**********************
 * GstVideoAggregator *
 *********************/

#define GST_TYPE_VIDEO_AGGREGATOR (gst_video_aggregator_get_type())
#define GST_VIDEO_AGGREGATOR(obj) \
        (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_VIDEO_AGGREGATOR, GstVideoAggregator))
#define GST_VIDEO_AGGREGATOR_CAST(obj) ((GstVideoAggregator *)(obj))
#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))

/**
 * 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_LARGE];
};

/**
 * GstVideoAggregatorClass:
 * @update_caps:              Optional.
 *                            Lets subclasses update the #GstCaps representing
 *                            the src pad caps before usage.  Return %NULL to indicate failure.
 * @aggregate_frames:         Lets subclasses aggregate frames that are ready. Subclasses
 *                            should iterate the GstElement.sinkpads and use the already
 *                            mapped #GstVideoFrame from gst_video_aggregator_pad_get_prepared_frame()
 *                            or directly use the #GstBuffer from gst_video_aggregator_pad_get_current_buffer()
 *                            if it needs to map the buffer in a special way. The result of the
 *                            aggregation should land in @outbuffer.
 * @create_output_buffer:     Optional.
 *                            Lets subclasses provide a #GstBuffer to be used as @outbuffer of
 *                            the #aggregate_frames vmethod.
 * @find_best_format:         Optional.
 *                            Lets subclasses decide of the best common format to use.
 **/
struct _GstVideoAggregatorClass
{
  /*< private >*/
  GstAggregatorClass parent_class;

  /*< public >*/
  GstCaps *          (*update_caps)               (GstVideoAggregator *  videoaggregator,
                                                   GstCaps            *  caps);
  GstFlowReturn      (*aggregate_frames)          (GstVideoAggregator *  videoaggregator,
                                                   GstBuffer          *  outbuffer);
  GstFlowReturn      (*create_output_buffer)      (GstVideoAggregator *  videoaggregator,
                                                   GstBuffer          ** outbuffer);
  void               (*find_best_format)          (GstVideoAggregator *  vagg,
                                                   GstCaps            *  downstream_caps,
                                                   GstVideoInfo       *  best_info,
                                                   gboolean           *  at_least_one_alpha);

  /* < private > */
  gpointer            _gst_reserved[GST_PADDING_LARGE];
};

GST_VIDEO_API
GType gst_video_aggregator_get_type       (void);

G_END_DECLS
#endif /* __GST_VIDEO_AGGREGATOR_H__ */