gstreamer/ges/ges-source.c

/* GStreamer Editing Services
 * Copyright (C) 2009 Edward Hervey <edward.hervey@collabora.co.uk>
 *               2009 Nokia Corporation
 *
 * 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.
 */

/**
 * SECTION:gessource
 * @title: GESSource
 * @short_description: Base Class for single-media sources
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "ges-internal.h"
#include "ges/ges-meta-container.h"
#include "ges-track-element.h"
#include "ges-source.h"
#include "ges-layer.h"
#include "gstframepositioner.h"
struct _GESSourcePrivate
{
  GstElement *topbin;
  GstElement *first_converter;
  GstElement *last_converter;
  GstPad *ghostpad;

};

G_DEFINE_TYPE_WITH_PRIVATE (GESSource, ges_source, GES_TYPE_TRACK_ELEMENT);

/******************************
 *   Internal helper methods  *
 ******************************/
static GstElement *
link_elements (GstElement * bin, GPtrArray * elements)
{
  GstElement *element, *prev = NULL, *first = NULL;
  gint i;

  for (i = 0; i < elements->len; i++) {
    element = elements->pdata[i];
    gst_bin_add (GST_BIN (bin), element);
    if (prev) {
      if (!gst_element_link_pads_full (prev, "src", element, "sink",
              GST_PAD_LINK_CHECK_NOTHING)) {
        if (!gst_element_link (prev, element)) {
          g_error ("Could not link %s and %s", GST_OBJECT_NAME (prev),
              GST_OBJECT_NAME (element));
        }
      }
    }
    prev = element;
    if (first == NULL)
      first = element;
  }

  return prev;
}

static void
_set_ghost_pad_target (GESSource * self, GstPad * srcpad, GstElement * element)
{
  GESSourcePrivate *priv = self->priv;
  gboolean use_converter = FALSE;
  GstPadLinkReturn link_return;

  if (priv->first_converter) {
    GstPad *pad = gst_element_get_static_pad (priv->first_converter, "sink");
    use_converter = gst_pad_can_link (srcpad, pad);
    gst_object_unref (pad);
  }

  if (use_converter) {
    GstPad *converter_src, *sinkpad;

    converter_src = gst_element_get_static_pad (priv->last_converter, "src");
    if (!gst_ghost_pad_set_target (GST_GHOST_PAD (priv->ghostpad),
            converter_src)) {
      GST_ERROR_OBJECT (self, "Could not set ghost target");
    }

    sinkpad = gst_element_get_static_pad (priv->first_converter, "sink");
    link_return = gst_pad_link (srcpad, sinkpad);
#ifndef GST_DISABLE_GST_DEBUG
    if (link_return != GST_PAD_LINK_OK) {
      GstCaps *srccaps = NULL;
      GstCaps *sinkcaps = NULL;

      srccaps = gst_pad_query_caps (srcpad, NULL);
      sinkcaps = gst_pad_query_caps (sinkpad, NULL);

      GST_ERROR_OBJECT (element, "Could not link source with "
          "conversion bin: %s (srcpad caps %" GST_PTR_FORMAT
          " sinkpad caps: %" GST_PTR_FORMAT ")",
          gst_pad_link_get_name (link_return), srccaps, sinkcaps);
      gst_caps_unref (srccaps);
      gst_caps_unref (sinkcaps);
    }
#endif

    gst_object_unref (converter_src);
    gst_object_unref (sinkpad);
  } else {
    if (!gst_ghost_pad_set_target (GST_GHOST_PAD (priv->ghostpad), srcpad))
      GST_ERROR_OBJECT (self, "Could not set ghost target");
  }

  gst_element_no_more_pads (element);
}

/* @elements: (transfer-full) */
GstElement *
ges_source_create_topbin (GESSource * source, const gchar * bin_name,
    GstElement * sub_element, GPtrArray * elements)
{
  GstElement *last;
  GstElement *bin;
  GstPad *sub_srcpad;
  GESSourcePrivate *priv = source->priv;

  bin = gst_bin_new (bin_name);
  if (!gst_bin_add (GST_BIN (bin), sub_element)) {
    GST_ERROR_OBJECT (source, "Could not add sub element: %" GST_PTR_FORMAT,
        sub_element);
    gst_object_unref (bin);
    return NULL;
  }

  priv->ghostpad = gst_object_ref (gst_ghost_pad_new_no_target ("src",
          GST_PAD_SRC));
  gst_pad_set_active (priv->ghostpad, TRUE);
  gst_element_add_pad (bin, priv->ghostpad);
  priv->topbin = gst_object_ref (bin);
  last = link_elements (bin, elements);
  if (last) {
    priv->first_converter = gst_object_ref (elements->pdata[0]);
    priv->last_converter = gst_object_ref (last);
  }

  sub_srcpad = gst_element_get_static_pad (sub_element, "src");
  if (sub_srcpad) {
    _set_ghost_pad_target (source, sub_srcpad, sub_element);
    gst_object_unref (sub_srcpad);
  } else {
    GST_INFO_OBJECT (source, "Waiting for pad added");
    g_signal_connect_swapped (sub_element, "pad-added",
        G_CALLBACK (_set_ghost_pad_target), source);
  }
  g_ptr_array_free (elements, TRUE);

  return bin;
}


static void
ges_source_dispose (GObject * object)
{
  GESSourcePrivate *priv = GES_SOURCE (object)->priv;

  gst_clear_object (&priv->first_converter);
  gst_clear_object (&priv->last_converter);
  gst_clear_object (&priv->topbin);
  gst_clear_object (&priv->ghostpad);

  G_OBJECT_CLASS (ges_source_parent_class)->dispose (object);
}

static void
ges_source_class_init (GESSourceClass * klass)
{
  GESTrackElementClass *track_class = GES_TRACK_ELEMENT_CLASS (klass);
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  track_class->nleobject_factorytype = "nlesource";
  track_class->create_element = NULL;
  object_class->dispose = ges_source_dispose;

  GES_TRACK_ELEMENT_CLASS_DEFAULT_HAS_INTERNAL_SOURCE (klass) = TRUE;
}

static void
ges_source_init (GESSource * self)
{
  self->priv = ges_source_get_instance_private (self);
}