gstreamer/ges/ges-smart-adder.c

/* -*- Mode: C; indent-tabs-mode: nil; c-basic-offset: 4; tab-width: 4 -*-  */
/*
 * gst-editing-services
 *
 * Copyright (C) 2013 Thibault Saunier <tsaunier@gnome.org>

 * gst-editing-services is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * gst-editing-services 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.";
 */
#include <gst/audio/audio.h>

#include "ges-types.h"
#include "ges-internal.h"
#include "ges-smart-adder.h"

G_DEFINE_TYPE (GESSmartAdder, ges_smart_adder, GST_TYPE_BIN);

#define GET_LOCK(obj) (&((GESSmartAdder*)(obj))->lock)
#define LOCK(obj) (g_mutex_lock (GET_LOCK(obj)))
#define UNLOCK(obj) (g_mutex_unlock (GET_LOCK(obj)))

static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("audio/x-raw")
    );

static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink_%u",
    GST_PAD_SINK,
    GST_PAD_REQUEST,
    GST_STATIC_CAPS ("audio/x-raw")
    );

#if G_BYTE_ORDER == G_LITTLE_ENDIAN
#define DEFAULT_CAPS "audio/x-raw,format=(string)S32LE;"
#else
#define DEFAULT_CAPS "audio/x-raw,format=(string)S32BE;"
#endif

typedef struct _PadInfos
{
  GESSmartAdder *self;
  GstPad *adder_pad;
  GstElement *bin;
} PadInfos;

static void
destroy_pad (PadInfos * infos)
{
  if (G_LIKELY (infos->bin)) {
    gst_element_set_state (infos->bin, GST_STATE_NULL);
    gst_element_unlink (infos->bin, infos->self->adder);
    gst_bin_remove (GST_BIN (infos->self), infos->bin);
  }

  if (infos->adder_pad) {
    gst_element_release_request_pad (infos->self->adder, infos->adder_pad);
    gst_object_unref (infos->adder_pad);
  }
  g_slice_free (PadInfos, infos);
}

/****************************************************
 *              GstElement vmetods                  *
 ****************************************************/
static GstPad *
_request_new_pad (GstElement * element, GstPadTemplate * templ,
    const gchar * name, const GstCaps * caps)
{
  GstPad *audioresample_srcpad, *audioconvert_sinkpad, *tmpghost;
  GstPad *ghost;
  GstElement *audioconvert, *audioresample;
  PadInfos *infos = g_slice_new0 (PadInfos);
  GESSmartAdder *self = GES_SMART_ADDER (element);

  infos->adder_pad = gst_element_request_pad (self->adder,
      gst_element_class_get_pad_template (GST_ELEMENT_GET_CLASS (self->adder),
          "sink_%u"), NULL, caps);

  if (infos->adder_pad == NULL) {
    GST_WARNING_OBJECT (element, "Could not get any pad from GstAdder");
    g_slice_free (PadInfos, infos);

    return NULL;
  }

  infos->self = self;

  infos->bin = gst_bin_new (NULL);
  audioconvert = gst_element_factory_make ("audioconvert", NULL);
  audioresample = gst_element_factory_make ("audioresample", NULL);

  gst_bin_add_many (GST_BIN (infos->bin), audioconvert, audioresample, NULL);
  gst_element_link_many (audioconvert, audioresample, NULL);

  audioconvert_sinkpad = gst_element_get_static_pad (audioconvert, "sink");
  tmpghost = GST_PAD (gst_ghost_pad_new (NULL, audioconvert_sinkpad));
  gst_object_unref (audioconvert_sinkpad);
  gst_pad_set_active (tmpghost, TRUE);
  gst_element_add_pad (GST_ELEMENT (infos->bin), tmpghost);

  gst_bin_add (GST_BIN (self), infos->bin);
  ghost = gst_ghost_pad_new (NULL, tmpghost);
  gst_pad_set_active (ghost, TRUE);
  if (!gst_element_add_pad (GST_ELEMENT (self), ghost))
    goto could_not_add;

  audioresample_srcpad = gst_element_get_static_pad (audioresample, "src");
  tmpghost = GST_PAD (gst_ghost_pad_new (NULL, audioresample_srcpad));
  gst_object_unref (audioresample_srcpad);
  gst_pad_set_active (tmpghost, TRUE);
  gst_element_add_pad (GST_ELEMENT (infos->bin), tmpghost);
  gst_pad_link (tmpghost, infos->adder_pad);

  LOCK (self);
  g_hash_table_insert (self->pads_infos, ghost, infos);
  UNLOCK (self);

  GST_DEBUG_OBJECT (self, "Returning new pad %" GST_PTR_FORMAT, ghost);
  return ghost;

could_not_add:
  {
    GST_ERROR_OBJECT (self, "could not add pad");
    destroy_pad (infos);
    return NULL;
  }
}

static void
_release_pad (GstElement * element, GstPad * pad)
{
  GST_DEBUG_OBJECT (element, "Releasing pad %" GST_PTR_FORMAT, pad);

  LOCK (element);
  g_hash_table_remove (GES_SMART_ADDER (element)->pads_infos, pad);
  UNLOCK (element);
}

/****************************************************
 *              GObject vmethods                    *
 ****************************************************/
static void
ges_smart_adder_dispose (GObject * object)
{
  GESSmartAdder *self = GES_SMART_ADDER (object);

  if (self->pads_infos) {
    g_hash_table_unref (self->pads_infos);
    self->pads_infos = NULL;
  }

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

static void
ges_smart_adder_finalize (GObject * object)
{
  GESSmartAdder *self = GES_SMART_ADDER (object);

  g_mutex_clear (&self->lock);

  G_OBJECT_CLASS (ges_smart_adder_parent_class)->finalize (object);
}

static void
ges_smart_adder_class_init (GESSmartAdderClass * klass)
{
/*   GstBinClass *parent_class = GST_BIN_CLASS (klass);
 */
  GObjectClass *object_class = G_OBJECT_CLASS (klass);
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  /* FIXME Make sure the AdderClass doesn get destroy before ourself */
  gst_element_class_add_static_pad_template (element_class, &src_template);
  gst_element_class_add_static_pad_template (element_class, &sink_template);
  gst_element_class_set_static_metadata (element_class, "GES Smart adder",
      "Generic/Audio",
      "Use adder making use of GES informations",
      "Thibault Saunier <thibault.saunier@collabora.com>");

  element_class->request_new_pad = GST_DEBUG_FUNCPTR (_request_new_pad);
  element_class->release_pad = GST_DEBUG_FUNCPTR (_release_pad);

  object_class->dispose = ges_smart_adder_dispose;
  object_class->finalize = ges_smart_adder_finalize;
}

static void
ges_smart_adder_init (GESSmartAdder * self)
{
  GstPad *pad;

  g_mutex_init (&self->lock);

  self->adder = gst_element_factory_make ("audiomixer", "smart-adder-adder");
  gst_bin_add (GST_BIN (self), self->adder);

  pad = gst_element_get_static_pad (self->adder, "src");
  self->srcpad = gst_ghost_pad_new ("src", pad);
  gst_pad_set_active (self->srcpad, TRUE);
  gst_object_unref (pad);

  gst_element_add_pad (GST_ELEMENT (self), self->srcpad);

  self->pads_infos = g_hash_table_new_full (g_direct_hash, g_direct_equal,
      NULL, (GDestroyNotify) destroy_pad);
}

static void
restriction_caps_cb (GESTrack * track,
    GParamSpec * arg G_GNUC_UNUSED, GESSmartAdder * self)
{
  GstCaps *caps;

  g_object_get (track, "restriction-caps", &caps, NULL);

  if (!caps)
    caps = gst_caps_from_string (DEFAULT_CAPS);

  GST_DEBUG_OBJECT (self, "Setting adder caps to %" GST_PTR_FORMAT, caps);
  g_object_set (self->adder, "caps", caps, NULL);
  gst_caps_unref (caps);
}

GstElement *
ges_smart_adder_new (GESTrack * track)
{
  GESSmartAdder *self;

  self = g_object_new (GES_TYPE_SMART_ADDER, NULL);

  self->track = track;

  if (track) {
    restriction_caps_cb (track, NULL, self);

    g_signal_connect (track, "notify::restriction-caps",
        G_CALLBACK (restriction_caps_cb), self);
  }

  /* FIXME Make adder smart and let it properly negotiate caps! */

  return GST_ELEMENT (self);
}