gstreamer/gst/aacparse/gstbaseparse.h

/* GStreamer
 * Copyright (C) 2008 Nokia Corporation. All rights reserved.
 *
 * Contact: Stefan Kost <stefan.kost@nokia.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.
 */

#ifndef __GST_BASE_PARSE_H__
#define __GST_BASE_PARSE_H__

#include <gst/gst.h>
#include <gst/base/gstadapter.h>

G_BEGIN_DECLS

#define GST_TYPE_BASE_PARSE		   (gst_base_parse_get_type())
#define GST_BASE_PARSE(obj)		   (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_BASE_PARSE,GstBaseParse))
#define GST_BASE_PARSE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_BASE_PARSE,GstBaseParseClass))
#define GST_BASE_PARSE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj),GST_TYPE_BASE_PARSE,GstBaseParseClass))
#define GST_IS_BASE_PARSE(obj)	   (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_BASE_PARSE))
#define GST_IS_BASE_PARSE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_BASE_PARSE))
#define GST_BASE_PARSE_CAST(obj)	((GstBaseParse *)(obj))

/**
 * GST_BASE_PARSE_SINK_NAME:
 *
 * the name of the templates for the sink pad
 */
#define GST_BASE_PARSE_SINK_NAME	"sink"
/**
 * GST_BASE_PARSE_SRC_NAME:
 *
 * the name of the templates for the source pad
 */
#define GST_BASE_PARSE_SRC_NAME	"src"

/**
 * GST_BASE_PARSE_SRC_PAD:
 * @obj: base parse instance
 *
 * Gives the pointer to the source #GstPad object of the element.
 *
 * Since: 0.10.x
 */
#define GST_BASE_PARSE_SRC_PAD(obj)		(GST_BASE_PARSE_CAST (obj)->srcpad)

/**
 * GST_BASE_PARSE_SINK_PAD:
 * @obj: base parse instance
 *
 * Gives the pointer to the sink #GstPad object of the element.
 *
 * Since: 0.10.x
 */
#define GST_BASE_PARSE_SINK_PAD(obj)	(GST_BASE_PARSE_CAST (obj)->sinkpad)

/**
 * GST_BASE_PARSE_FLOW_DROPPED:
 *
 * A #GstFlowReturn that can be returned from parse_frame to
 * indicate that no output buffer was generated.
 *
 * Since: 0.10.x
 */
#define GST_BASE_PARSE_FLOW_DROPPED   GST_FLOW_CUSTOM_SUCCESS

/**
 * GST_BASE_PARSE_LOCK:
 * @obj: base parse instance
 *
 * Obtain a lock to protect the parse function from concurrent access.
 *
 * Since: 0.10.x
 */
#define GST_BASE_PARSE_LOCK(obj)   g_mutex_lock (GST_BASE_PARSE_CAST (obj)->parse_lock)

/**
 * GST_BASE_PARSE_UNLOCK:
 * @obj: base parse instance
 *
 * Release the lock that protects the parse function from concurrent access.
 *
 * Since: 0.10.x
 */
#define GST_BASE_PARSE_UNLOCK(obj) g_mutex_unlock (GST_BASE_PARSE_CAST (obj)->parse_lock)

typedef struct _GstBaseParse GstBaseParse;
typedef struct _GstBaseParseClass GstBaseParseClass;
typedef struct _GstBaseParsePrivate GstBaseParsePrivate;
typedef struct _GstBaseParseClassPrivate GstBaseParseClassPrivate;

/**
 * GstBaseParse:
 * @element: the parent element.
 *
 * The opaque #GstBaseParse data structure.
 */
struct _GstBaseParse {
  GstElement	 element;
  GstAdapter   *adapter;

  /*< protected >*/
  /* source and sink pads */
  GstPad	*sinkpad;
  GstPad	*srcpad;

  /* MT-protected (with STREAM_LOCK) */
  GstSegment     segment;

  /* Newsegment event to be sent after SEEK */
  GstEvent       *pending_segment;

  /* Segment event that closes the running segment prior to SEEK */
  GstEvent       *close_segment;

  /* Caps nego done already? */
  gboolean   negotiated;

  GMutex	*parse_lock;

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

/**
 * GstBaseParseClass:
 * @start:          Optional.
 *                  Called when the element starts processing.
 *                  Allows opening external resources.
 * @stop:           Optional.
 *                  Called when the element stops processing.
 *                  Allows closing external resources.
 * @set_sink_caps:  allows the subclass to be notified of the actual caps set.
 * @check_valid_frame:  Check if the given piece of data contains a valid
 *                      frame.
 * @parse_frame:    Parse the already checked frame. Subclass need to
 *                  set the buffer timestamp, duration, caps and possibly
 *                  other necessary metadata. This is called with srcpad's
 *                  STREAM_LOCK held.
 * @convert:        Optional.
 *                  Convert between formats.
 * @find_frame:     Optional.
 *                  Finds a frame. Gets a position passed and should return
 *                  TRUE and the offset in bytes where this position is.
 *                  Will only be called in pull mode and the subclass can pull
 *                  whatever it wants from upstream. If not implemented,
 *                  the base class will implement it by calling
 *                  @check_valid_frame and @parse_frame to find the wanted
 *                  frame and build a seek table.
 * @event:          Optional.
 *                  Event handler on the sink pad. This function should return
 *                  TRUE if the event was handled and can be dropped.
 * @src_event:      Optional.
 *                  Event handler on the source pad. Should return TRUE
 *                  if the event was handled and can be dropped.
 * @is_seekable:    Optional.
 *                  Subclass can override this if it wants to control the
 *                  seekability of the stream. Otherwise the element assumes
 *                  that stream is always seekable.
 *
 * Subclasses can override any of the available virtual methods or not, as
 * needed. At minimum @check_valid_frame and @parse_frame needs to be
 * overridden.
 */
struct _GstBaseParseClass {
  GstElementClass parent_class;

  /*< public >*/
  /* virtual methods for subclasses */

  gboolean      (*start)              (GstBaseParse *parse);

  gboolean      (*stop)               (GstBaseParse *parse);

  gboolean      (*set_sink_caps)      (GstBaseParse *parse,
                                       GstCaps *caps);

  gboolean      (*check_valid_frame)  (GstBaseParse *parse,
                                       GstBuffer *buffer,
                                       guint *framesize,
                                       gint *skipsize);

  GstFlowReturn (*parse_frame)        (GstBaseParse *parse,
                                       GstBuffer *buffer);

  gboolean      (*convert)            (GstBaseParse * parse,
                                       GstFormat src_format,
                                       gint64 src_value,
                                       GstFormat dest_format,
                                       gint64 * dest_value);

  gboolean      (*find_frame)         (GstBaseParse *parse,
                                       GstFormat src_format,
                                       gint64 src_value,
                                       gint64 * dest_value);

  gboolean      (*event)              (GstBaseParse *parse,
                                       GstEvent *event);

  gboolean      (*src_event)          (GstBaseParse *parse,
                                       GstEvent *event);

  gboolean      (*is_seekable)        (GstBaseParse *parse);

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

GType           gst_base_parse_get_type         (void);


void gst_base_parse_set_duration (GstBaseParse *parse,
                                  GstFormat fmt,
                                  gint64 duration);

void gst_base_parse_set_min_frame_size (GstBaseParse *parse,
                                        guint min_size);

G_END_DECLS

#endif /* __GST_BASE_PARSE_H__ */