/* GStreamer

 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>

 *               2000,2005 Wim Taymans <wim@fluendo.com>

 *

 * gstpushsrc.c:

 *

 * 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.

 */

/**

 * SECTION:gstpushsrc

 * @short_description: Base class for push based source elements

 * @see_also: #GstBaseSrc

 *

 * This class is mostly useful for elements that cannot do

 * random access, or at least very slowly. The source usually

 * prefers to push out a fixed size buffer.

 *

 * Subclasses usually operate in a format that is different from the

 * default GST_FORMAT_BYTES format of #GstBaseSrc.

 *

 * Classes extending this base class will usually be scheduled

 * in a push based mode. If the peer accepts to operate without

 * offsets and within the limits of the allowed block size, this

 * class can operate in getrange based mode automatically. To make

 * this possible, the subclass should override the ::check_get_range

 * method.

 *

 * The subclass should extend the methods from the baseclass in

 * addition to the ::create method.

 *

 * Seeking, flushing, scheduling and sync is all handled by this

 * base class.

 *

 * Last reviewed on 2006-07-04 (0.10.9)

 */

#ifdef HAVE_CONFIG_H

#  include "config.h"

#endif

#include <stdlib.h>

#include <string.h>

#include "gstpushsrc.h"

#include "gsttypefindhelper.h"

#include <gst/gstmarshal.h>

GST_DEBUG_CATEGORY_STATIC (gst_push_src_debug);

#define GST_CAT_DEFAULT gst_push_src_debug

#define _do_init(type) \

    GST_DEBUG_CATEGORY_INIT (gst_push_src_debug, "pushsrc", 0, \

        "pushsrc element");

GST_BOILERPLATE_FULL (GstPushSrc, gst_push_src, GstBaseSrc, GST_TYPE_BASE_SRC,

    _do_init);

static gboolean gst_push_src_check_get_range (GstBaseSrc * src);

static GstFlowReturn gst_push_src_create (GstBaseSrc * bsrc, guint64 offset,

    guint length, GstBuffer ** ret);

static void

gst_push_src_base_init (gpointer g_class)

{

  /* nop */

}

static void

gst_push_src_class_init (GstPushSrcClass * klass)

{

  GstBaseSrcClass *gstbasesrc_class = (GstBaseSrcClass *) klass;

  gstbasesrc_class->create = GST_DEBUG_FUNCPTR (gst_push_src_create);

  gstbasesrc_class->check_get_range =

      GST_DEBUG_FUNCPTR (gst_push_src_check_get_range);

}

static void

gst_push_src_init (GstPushSrc * pushsrc, GstPushSrcClass * klass)

{

  /* nop */

}

static gboolean

gst_push_src_check_get_range (GstBaseSrc * src)

{

  /* a pushsrc can by default never operate in pull mode override

   * if you want something different. */

  return FALSE;

}

static GstFlowReturn

gst_push_src_create (GstBaseSrc * bsrc, guint64 offset, guint length,

    GstBuffer ** ret)

{

  GstFlowReturn fret;

  GstPushSrc *src;

  GstPushSrcClass *pclass;

  src = GST_PUSH_SRC (bsrc);

  pclass = GST_PUSH_SRC_GET_CLASS (src);

  if (pclass->create)

    fret = pclass->create (src, ret);

  else

    fret = GST_FLOW_ERROR;

  return fret;

}