gstreamer/ges/ges-audio-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:gesaudiosource
 * @short_description: Base Class for audio sources
 */

#include "ges-internal.h"
#include "ges/ges-meta-container.h"
#include "ges-track-element.h"
#include "ges-audio-source.h"
#include "ges-layer.h"

G_DEFINE_ABSTRACT_TYPE (GESAudioSource, ges_audio_source, GES_TYPE_SOURCE);

struct _GESAudioSourcePrivate
{
  /*  Dummy variable */
  void *nothing;
};

static void
_sync_element_to_layer_property_float (GESTrackElement * trksrc,
    GstElement * element, const gchar * meta, const gchar * propname)
{
  GESTimelineElement *parent;
  GESLayer *layer;
  gfloat value;

  parent = ges_timeline_element_get_parent (GES_TIMELINE_ELEMENT (trksrc));
  layer = ges_clip_get_layer (GES_CLIP (parent));

  gst_object_unref (parent);

  if (layer != NULL) {

    ges_meta_container_get_float (GES_META_CONTAINER (layer), meta, &value);
    g_object_set (element, propname, value, NULL);
    GST_DEBUG_OBJECT (trksrc, "Setting %s to %f", propname, value);

  } else {

    GST_DEBUG_OBJECT (trksrc, "NOT setting the %s", propname);
  }

  gst_object_unref (layer);
}

static GstElement *
ges_audio_source_create_element (GESTrackElement * trksrc)
{
  GstElement *volume, *vbin;
  GstElement *topbin;
  GstElement *sub_element;
  GESAudioSourceClass *source_class = GES_AUDIO_SOURCE_GET_CLASS (trksrc);
  const gchar *props[] = { "volume", "mute", NULL };

  if (!source_class->create_source)
    return NULL;

  sub_element = source_class->create_source (trksrc);

  GST_DEBUG_OBJECT (trksrc, "Creating a bin sub_element ! volume");
  vbin =
      gst_parse_bin_from_description
      ("audioconvert ! audioresample ! volume name=v", TRUE, NULL);
  topbin = ges_source_create_topbin ("audiosrcbin", sub_element, vbin, NULL);
  volume = gst_bin_get_by_name (GST_BIN (vbin), "v");

  _sync_element_to_layer_property_float (trksrc, volume, GES_META_VOLUME,
      "volume");
  ges_track_element_add_children_props (trksrc, volume, NULL, NULL, props);
  gst_object_unref (volume);

  return topbin;
}

static void
ges_audio_source_class_init (GESAudioSourceClass * klass)
{
  GESTrackElementClass *track_class = GES_TRACK_ELEMENT_CLASS (klass);
  GESAudioSourceClass *audio_source_class = GES_AUDIO_SOURCE_CLASS (klass);

  g_type_class_add_private (klass, sizeof (GESAudioSourcePrivate));

  track_class->gnlobject_factorytype = "gnlsource";
  track_class->create_element = ges_audio_source_create_element;
  audio_source_class->create_source = NULL;
}

static void
ges_audio_source_init (GESAudioSource * self)
{
  self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
      GES_TYPE_AUDIO_SOURCE, GESAudioSourcePrivate);
}