path: root/src/empathy-audio-src.c

/*
 * empathy-gst-audio-src.c - Source for EmpathyGstAudioSrc
 * Copyright (C) 2008 Collabora Ltd.
 * @author Sjoerd Simons <sjoerd.simons@collabora.co.uk>
 *
 * This library 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 2.1 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser 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
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>

#include <gst/interfaces/mixer.h>

#include <libempathy/empathy-utils.h>
#include <libempathy-gtk/empathy-call-utils.h>

#include "empathy-audio-src.h"

#include "empathy-mic-monitor.h"

#define DEBUG_FLAG EMPATHY_DEBUG_VOIP
#include <libempathy/empathy-debug.h>

G_DEFINE_TYPE(EmpathyGstAudioSrc, empathy_audio_src, GST_TYPE_BIN)

/* signal enum */
enum
{
    PEAK_LEVEL_CHANGED,
    RMS_LEVEL_CHANGED,
    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = {0};

enum {
    PROP_VOLUME = 1,
    PROP_MUTE,
    PROP_RMS_LEVEL,
    PROP_PEAK_LEVEL,
    PROP_MICROPHONE,
};

/* private structure */
struct _EmpathyGstAudioSrcPrivate
{
  gboolean dispose_has_run;
  GstElement *src;
  GstElement *level;

  EmpathyMicMonitor *mic_monitor;

  /* 0 if not known yet */
  guint source_output_idx;
  /* G_MAXUINT if not known yet */
  guint source_idx;

  gdouble peak_level;
  gdouble rms_level;

  gdouble volume;
  gboolean mute;
  /* the mixer track on src we follow and adjust */
  GstMixerTrack *track;

  GMutex lock;
  guint level_idle_id;
  guint volume_idle_id;
};

#define EMPATHY_GST_AUDIO_SRC_GET_PRIVATE(o) \
  (G_TYPE_INSTANCE_GET_PRIVATE ((o), EMPATHY_TYPE_GST_AUDIO_SRC, \
  EmpathyGstAudioSrcPrivate))

/* There is no predefined maximum channels by gstreamer, just pick 32, which is
 * the same as the pulseaudio maximum */
#define MAX_MIC_CHANNELS 32

static void
empathy_audio_set_hw_mute (EmpathyGstAudioSrc *self, gboolean mute)
{
  g_mutex_lock (&self->priv->lock);
  /* If there is no mixer available ignore the setting */
  if (self->priv->track == NULL)
    goto out;

  gst_mixer_set_mute (GST_MIXER (self->priv->src), self->priv->track, mute);

out:
  g_mutex_unlock (&self->priv->lock);
  self->priv->mute = mute;
}

static gboolean
empathy_audio_src_get_hw_mute (EmpathyGstAudioSrc *self)
{
  gboolean result = self->priv->mute;

  g_mutex_lock (&self->priv->lock);
  if (self->priv->track == NULL)
    goto out;

  result = GST_MIXER_TRACK_HAS_FLAG (self->priv->track, GST_MIXER_TRACK_MUTE);
out:
  g_mutex_unlock (&self->priv->lock);

  return result;
}

static void
empathy_audio_src_set_hw_volume (EmpathyGstAudioSrc *self,
    gdouble volume)
{
  gint volumes[MAX_MIC_CHANNELS];
  int i;

  g_mutex_lock (&self->priv->lock);
  /* If there is no mixer available ignore the setting */
  if (self->priv->track == NULL)
    goto out;

  for (i = 0; i < MAX_MIC_CHANNELS; i++)
    volumes[i] = self->priv->track->max_volume * volume;

  gst_mixer_set_volume (GST_MIXER (self->priv->src),
    self->priv->track, volumes);

out:
   g_mutex_unlock (&self->priv->lock);

  self->priv->volume = volume;
}

static gdouble
empathy_audio_src_get_hw_volume (EmpathyGstAudioSrc *self)
{
  gint volumes[MAX_MIC_CHANNELS];
  gdouble result = self->priv->volume;

  g_mutex_lock (&self->priv->lock);
  if (self->priv->track == NULL)
    goto out;

  gst_mixer_get_volume (GST_MIXER (self->priv->src),
    self->priv->track, volumes);
  result = volumes[0]/(gdouble)self->priv->track->max_volume;

out:
  g_mutex_unlock (&self->priv->lock);

  return result;
}


gboolean
empathy_audio_src_supports_changing_mic (EmpathyGstAudioSrc *self)
{
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (self);
  GObjectClass *object_class;

  object_class = G_OBJECT_GET_CLASS (priv->src);

  return (g_object_class_find_property (object_class,
          "source-output-index") != NULL);
}

static guint
empathy_audio_src_get_mic_index (EmpathyGstAudioSrc *self)
{
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (self);
  guint audio_src_idx = PA_INVALID_INDEX;

  if (empathy_audio_src_supports_changing_mic (self))
    g_object_get (priv->src,
      "source-output-index", &audio_src_idx,
      NULL);

  return audio_src_idx;
}

static void
empathy_audio_src_microphone_changed_cb (EmpathyMicMonitor *monitor,
    guint source_output_idx,
    guint source_idx,
    gpointer user_data)
{
  EmpathyGstAudioSrc *self = user_data;
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (self);
  guint audio_src_idx;

  audio_src_idx = empathy_audio_src_get_mic_index (self);

  if (source_output_idx == PA_INVALID_INDEX
      || source_output_idx != audio_src_idx)
    return;

  if (priv->source_idx == source_idx)
    return;

  priv->source_idx = source_idx;
  g_object_notify (G_OBJECT (self), "microphone");
}

static void
empathy_audio_src_get_current_mic_cb (GObject *source_object,
    GAsyncResult *result,
    gpointer user_data)
{
  EmpathyMicMonitor *monitor = EMPATHY_MIC_MONITOR (source_object);
  EmpathyGstAudioSrc *self = user_data;
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (self);
  guint source_idx;
  GError *error = NULL;

  source_idx = empathy_mic_monitor_get_current_mic_finish (monitor, result, &error);

  if (error != NULL)
    {
      DEBUG ("Failed to get current mic: %s", error->message);
      g_clear_error (&error);
      return;
    }

  if (priv->source_idx == source_idx)
    return;

  priv->source_idx = source_idx;
  g_object_notify (G_OBJECT (self), "microphone");
}

static void
empathy_audio_src_source_output_index_notify (GObject *object,
    GParamSpec *pspec,
    EmpathyGstAudioSrc *self)
{
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (self);
  guint source_output_idx;

  source_output_idx = empathy_audio_src_get_mic_index (self);

  if (source_output_idx == PA_INVALID_INDEX)
    return;

  if (priv->source_output_idx == source_output_idx)
    return;

  /* It's actually changed. */
  priv->source_output_idx = source_output_idx;

  empathy_mic_monitor_get_current_mic_async (priv->mic_monitor,
      source_output_idx, empathy_audio_src_get_current_mic_cb, self);
}

static GstMixerTrack *
empathy_audio_src_get_track (GstElement *src)
{
  const GList *t;
  GstMixerTrack *track = NULL;

  if (!gst_element_implements_interface (src, GST_TYPE_MIXER))
    {
      g_warning ("No mixer interface implementation, can't control volume");
      return NULL;
    }

  for (t = gst_mixer_list_tracks (GST_MIXER (src));
      t != NULL; t = g_list_next (t))
    {
      GstMixerTrack *tr = t->data;
      if (!tp_strdiff (tr->label, "Master"))
        {
          track = tr;
          break;
        }
    }

  if (track == NULL)
    {
      g_warning ("No suitable track found");
    }
  else if (track->num_channels > MAX_MIC_CHANNELS)
    {
      g_warning ("Microphones with more then %d channels not supported ",
        MAX_MIC_CHANNELS);
      track = NULL;
    }

  return track;
}

static GstElement *
create_src (void)
{
  GstElement *src;
  const gchar *description;

  description = g_getenv ("EMPATHY_AUDIO_SRC");

  if (description != NULL)
    {
      GError *error = NULL;

      src = gst_parse_bin_from_description (description, TRUE, &error);
      if (src == NULL)
        {
          DEBUG ("Failed to create bin %s: %s", description, error->message);
          g_error_free (error);
        }

      return src;
    }

  /* Use pulsesrc as default */
  src = gst_element_factory_make ("pulsesrc", NULL);
  if (src == NULL)
    return NULL;

  empathy_call_set_stream_properties (src, TRUE);

  /* Set latency (buffering on the PulseAudio side) of 20ms */
  g_object_set (src, "buffer-time", (gint64) 20000, NULL);

  return src;
}

static void
empathy_audio_src_init (EmpathyGstAudioSrc *obj)
{
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (obj);
  GstPad *ghost, *src;
  GstElement *capsfilter;
  GstCaps *caps;

  obj->priv = priv;
  priv->peak_level = -G_MAXDOUBLE;
  g_mutex_init (&priv->lock);

  priv->volume = 1.0;

  priv->src = create_src ();
  if (priv->src == NULL)
    return;

  gst_bin_add (GST_BIN (obj), priv->src);

  /* Explicitly state what format we want from pulsesrc. This pushes resampling
   * and format conversion as early as possible, lowering the amount of data
   * transferred and thus improving performance. When moving to GStreamer
   * 0.11/1.0, this should change so that we actually request what the encoder
   * wants downstream. */
  caps = gst_caps_new_simple ("audio/x-raw-int",
      "channels", G_TYPE_INT, 1,
      "width", G_TYPE_INT, 16,
      "depth", G_TYPE_INT, 16,
      "rate", G_TYPE_INT, 32000,
      NULL);
  capsfilter = gst_element_factory_make ("capsfilter", NULL);
  g_object_set (G_OBJECT (capsfilter), "caps", caps, NULL);
  gst_bin_add (GST_BIN (obj), capsfilter);
  gst_element_link (priv->src, capsfilter);

  priv->level = gst_element_factory_make ("level", NULL);
  gst_bin_add (GST_BIN (obj), priv->level);
  gst_element_link (capsfilter, priv->level);

  src = gst_element_get_static_pad (priv->level, "src");

  ghost = gst_ghost_pad_new ("src", src);
  gst_element_add_pad (GST_ELEMENT (obj), ghost);

  gst_object_unref (G_OBJECT (src));

  /* Listen to changes to GstPulseSrc:source-output-index so we know when
   * it's no longer PA_INVALID_INDEX (starting for the first time) or if it
   * changes (READY->NULL->READY...) */
  g_signal_connect (priv->src, "notify::source-output-index",
      G_CALLBACK (empathy_audio_src_source_output_index_notify),
      obj);

  priv->mic_monitor = empathy_mic_monitor_new ();
  g_signal_connect (priv->mic_monitor, "microphone-changed",
      G_CALLBACK (empathy_audio_src_microphone_changed_cb), obj);

  priv->source_idx = PA_INVALID_INDEX;
}

static void empathy_audio_src_dispose (GObject *object);
static void empathy_audio_src_finalize (GObject *object);
static void empathy_audio_src_handle_message (GstBin *bin,
  GstMessage *message);

static gboolean empathy_audio_src_levels_updated (gpointer user_data);

static void
empathy_audio_src_set_property (GObject *object,
  guint property_id, const GValue *value, GParamSpec *pspec)
{
  switch (property_id)
    {
      case PROP_VOLUME:
        empathy_audio_src_set_hw_volume (EMPATHY_GST_AUDIO_SRC (object),
          g_value_get_double (value));
        break;
      case PROP_MUTE:
        empathy_audio_set_hw_mute (EMPATHY_GST_AUDIO_SRC (object),
          g_value_get_boolean (value));
        break;
      default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
    }
}

static void
empathy_audio_src_get_property (GObject *object,
  guint property_id, GValue *value, GParamSpec *pspec)
{
  EmpathyGstAudioSrc *self = EMPATHY_GST_AUDIO_SRC (object);
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (self);

  switch (property_id)
    {
      case PROP_VOLUME:
        g_value_set_double (value, priv->volume);
        break;
      case PROP_MUTE:
        g_value_set_boolean (value, priv->mute);
        break;
      case PROP_PEAK_LEVEL:
        g_mutex_lock (&priv->lock);
        g_value_set_double (value, priv->peak_level);
        g_mutex_unlock (&priv->lock);
        break;
      case PROP_RMS_LEVEL:
        g_mutex_lock (&priv->lock);
        g_value_set_double (value, priv->rms_level);
        g_mutex_unlock (&priv->lock);
        break;
      case PROP_MICROPHONE:
        g_value_set_uint (value, priv->source_idx);
        break;
      default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
    }
}

static void
empathy_audio_src_class_init (EmpathyGstAudioSrcClass
  *empathy_audio_src_class)
{
  GObjectClass *object_class = G_OBJECT_CLASS (empathy_audio_src_class);
  GstBinClass *gstbin_class = GST_BIN_CLASS (empathy_audio_src_class);
  GParamSpec *param_spec;

  g_type_class_add_private (empathy_audio_src_class,
    sizeof (EmpathyGstAudioSrcPrivate));

  object_class->dispose = empathy_audio_src_dispose;
  object_class->finalize = empathy_audio_src_finalize;

  object_class->set_property = empathy_audio_src_set_property;
  object_class->get_property = empathy_audio_src_get_property;

  gstbin_class->handle_message =
    GST_DEBUG_FUNCPTR (empathy_audio_src_handle_message);

  param_spec = g_param_spec_double ("volume", "Volume", "volume contol",
    0.0, 5.0, 1.0,
    G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
  g_object_class_install_property (object_class, PROP_VOLUME, param_spec);

  param_spec = g_param_spec_boolean ("mute", "Mute", "mute contol",
    FALSE,
    G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
  g_object_class_install_property (object_class, PROP_MUTE, param_spec);

  param_spec = g_param_spec_double ("peak-level", "peak level", "peak level",
    -G_MAXDOUBLE, G_MAXDOUBLE, 0,
    G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
  g_object_class_install_property (object_class, PROP_PEAK_LEVEL, param_spec);

  param_spec = g_param_spec_uint ("microphone", "microphone", "microphone",
    0, G_MAXUINT, G_MAXUINT,
    G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
  g_object_class_install_property (object_class, PROP_MICROPHONE, param_spec);

  signals[PEAK_LEVEL_CHANGED] = g_signal_new ("peak-level-changed",
    G_TYPE_FROM_CLASS (empathy_audio_src_class),
    G_SIGNAL_RUN_LAST,
    0,
    NULL, NULL,
    g_cclosure_marshal_generic,
    G_TYPE_NONE, 1, G_TYPE_DOUBLE);

  param_spec = g_param_spec_double ("rms-level", "RMS level", "RMS level",
    -G_MAXDOUBLE, G_MAXDOUBLE, 0,
    G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
  g_object_class_install_property (object_class, PROP_RMS_LEVEL, param_spec);

  signals[RMS_LEVEL_CHANGED] = g_signal_new ("rms-level-changed",
    G_TYPE_FROM_CLASS (empathy_audio_src_class),
    G_SIGNAL_RUN_LAST,
    0,
    NULL, NULL,
    g_cclosure_marshal_generic,
    G_TYPE_NONE, 1, G_TYPE_DOUBLE);
}

void
empathy_audio_src_dispose (GObject *object)
{
  EmpathyGstAudioSrc *self = EMPATHY_GST_AUDIO_SRC (object);
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (self);

  if (priv->dispose_has_run)
    return;

  priv->dispose_has_run = TRUE;

  if (priv->level_idle_id != 0)
    g_source_remove (priv->level_idle_id);
  priv->level_idle_id = 0;

  if (priv->volume_idle_id != 0)
    g_source_remove (priv->volume_idle_id);
  priv->volume_idle_id = 0;

  tp_clear_object (&priv->mic_monitor);

  /* release any references held by the object here */

  if (G_OBJECT_CLASS (empathy_audio_src_parent_class)->dispose)
    G_OBJECT_CLASS (empathy_audio_src_parent_class)->dispose (object);
}

void
empathy_audio_src_finalize (GObject *object)
{
  EmpathyGstAudioSrc *self = EMPATHY_GST_AUDIO_SRC (object);
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (self);

  /* free any data held directly by the object here */
  g_mutex_clear (&priv->lock);

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

static gboolean
empathy_audio_src_levels_updated (gpointer user_data)
{
  EmpathyGstAudioSrc *self = EMPATHY_GST_AUDIO_SRC (user_data);
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (self);

  g_mutex_lock (&priv->lock);

  g_signal_emit (self, signals[PEAK_LEVEL_CHANGED], 0, priv->peak_level);
  g_signal_emit (self, signals[RMS_LEVEL_CHANGED], 0, priv->rms_level);
  priv->level_idle_id = 0;

  g_mutex_unlock (&priv->lock);

  return FALSE;
}

static gboolean
empathy_audio_src_volume_changed (gpointer user_data)
{
  EmpathyGstAudioSrc *self = EMPATHY_GST_AUDIO_SRC (user_data);
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (self);
  gdouble volume;
  gboolean mute;

  g_mutex_lock (&priv->lock);
  priv->volume_idle_id = 0;
  g_mutex_unlock (&priv->lock);

  volume = empathy_audio_src_get_hw_volume (self);

  if (volume != priv->volume)
    {
      priv->volume = volume;
      g_object_notify (G_OBJECT (self), "volume");
    }

  mute = empathy_audio_src_get_hw_mute (self);
  if (mute != priv->mute)
    {
      priv->mute = mute;
      g_object_notify (G_OBJECT (self), "mute");
    }

  return FALSE;
}

static void
empathy_audio_src_handle_message (GstBin *bin, GstMessage *message)
{
  EmpathyGstAudioSrc *self = EMPATHY_GST_AUDIO_SRC (bin);
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (self);

  if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_ELEMENT &&
      GST_MESSAGE_SRC (message) == GST_OBJECT (priv->level))
    {
      const GstStructure *s;
      const gchar *name;
      const GValue *list;
      guint i, len;
      gdouble peak = -G_MAXDOUBLE;
      gdouble rms = -G_MAXDOUBLE;

      s = gst_message_get_structure (message);
      name = gst_structure_get_name (s);

      if (g_strcmp0 ("level", name) != 0)
        goto out;

      list = gst_structure_get_value (s, "peak");
      len = gst_value_list_get_size (list);

      for (i =0 ; i < len; i++)
        {
          const GValue *value;
          gdouble db;

          value = gst_value_list_get_value (list, i);
          db = g_value_get_double (value);
          peak = MAX (db, peak);
        }

      list = gst_structure_get_value (s, "rms");
      len = gst_value_list_get_size (list);

      for (i =0 ; i < len; i++)
        {
          const GValue *value;
          gdouble db;

          value = gst_value_list_get_value (list, i);
          db = g_value_get_double (value);
          rms = MAX (db, rms);
        }

      g_mutex_lock (&priv->lock);

      priv->peak_level = peak;
      priv->rms_level = rms;
      if (priv->level_idle_id == 0)
        priv->level_idle_id = g_idle_add (
          empathy_audio_src_levels_updated, self);

      g_mutex_unlock (&priv->lock);
    }
  else if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_ELEMENT &&
        GST_MESSAGE_SRC (message) == GST_OBJECT (priv->src))
    {
      GstMixerTrack *track = NULL;

      /* Listen for mute or volume changes on the src element */
      if (gst_mixer_message_get_type (message) ==
          GST_MIXER_MESSAGE_VOLUME_CHANGED)
        gst_mixer_message_parse_volume_changed (message, &track,
            NULL, NULL);

      if (gst_mixer_message_get_type (message) ==
          GST_MIXER_MESSAGE_MUTE_TOGGLED)
        gst_mixer_message_parse_mute_toggled (message, &track, NULL);

      g_mutex_lock (&priv->lock);

      if (track != NULL && track == priv->track && priv->volume_idle_id == 0)
        priv->volume_idle_id = g_idle_add (
            empathy_audio_src_volume_changed, self);

      g_mutex_unlock (&priv->lock);
    }
  else if  (GST_MESSAGE_TYPE (message) == GST_MESSAGE_STATE_CHANGED &&
      GST_MESSAGE_SRC (message) == GST_OBJECT (priv->src))
    {
      GstState old, new;

      gst_message_parse_state_changed (message, &old, &new, NULL);

      /* GstMixer is only available in state >= READY, so only start
       * controlling the source element when going to ready state and stop
       * doing so when going below ready. Furthermore once we have mixer read
       * the current volume level from it and remove the settings done by
       * Empathy. We want to pick up the level pulseaudio saved */
      if (old == GST_STATE_NULL && new == GST_STATE_READY)
        {
          g_mutex_lock (&priv->lock);
          priv->track = empathy_audio_src_get_track (priv->src);
          if (priv->track != NULL)
            priv->volume_idle_id = g_idle_add (
              empathy_audio_src_volume_changed, self);
          g_mutex_unlock (&priv->lock);
        }
      else if (old == GST_STATE_READY && new == GST_STATE_NULL)
        {
          g_mutex_lock (&priv->lock);
          priv->track = NULL;
          g_mutex_unlock (&priv->lock);
        }
    }

out:
   GST_BIN_CLASS (empathy_audio_src_parent_class)->handle_message (bin,
    message);
}

GstElement *
empathy_audio_src_new (void)
{
  static gboolean registered = FALSE;

  if (!registered) {
    if (!gst_element_register (NULL, "empathyaudiosrc",
            GST_RANK_NONE, EMPATHY_TYPE_GST_AUDIO_SRC))
      return NULL;
    registered = TRUE;
  }
  return gst_element_factory_make ("empathyaudiosrc", NULL);
}

void
empathy_audio_src_set_echo_cancel (EmpathyGstAudioSrc *src,
  gboolean enable)
{
  DEBUG ("Src echo cancellation setting: %s", enable ? "on" : "off");
  empathy_call_set_stream_properties (src->priv->src, enable);
}

void
empathy_audio_src_set_volume (EmpathyGstAudioSrc *src, gdouble volume)
{
  g_object_set (src, "volume", volume, NULL);
}

gdouble
empathy_audio_src_get_volume (EmpathyGstAudioSrc *src)
{
  return src->priv->volume;
}

guint
empathy_audio_src_get_microphone (EmpathyGstAudioSrc *src)
{
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (src);

  return priv->source_idx;
}

static void
empathy_audio_src_change_microphone_cb (GObject *source_object,
    GAsyncResult *result,
    gpointer user_data)
{
  EmpathyMicMonitor *monitor = EMPATHY_MIC_MONITOR (source_object);
  GSimpleAsyncResult *simple = user_data;
  GError *error = NULL;

  if (!empathy_mic_monitor_change_microphone_finish (monitor,
          result, &error))
    {
      g_simple_async_result_take_error (simple, error);
    }

  g_simple_async_result_complete (simple);
  g_object_unref (simple);
}

void
empathy_audio_src_change_microphone_async (EmpathyGstAudioSrc *src,
    guint microphone,
    GAsyncReadyCallback callback,
    gpointer user_data)
{
  EmpathyGstAudioSrcPrivate *priv = EMPATHY_GST_AUDIO_SRC_GET_PRIVATE (src);
  guint source_output_idx;
  GSimpleAsyncResult *simple;

  simple = g_simple_async_result_new (G_OBJECT (src), callback, user_data,
      empathy_audio_src_change_microphone_async);

  if (!empathy_audio_src_supports_changing_mic (src))
    {
      g_simple_async_result_set_error (simple, G_IO_ERROR, G_IO_ERROR_FAILED,
          "pulsesrc is not new enough to support changing microphone");
      g_simple_async_result_complete_in_idle (simple);
      g_object_unref (simple);
      return;
    }

  source_output_idx = empathy_audio_src_get_mic_index (src);

  if (source_output_idx == PA_INVALID_INDEX)
    {
      g_simple_async_result_set_error (simple, G_IO_ERROR, G_IO_ERROR_FAILED,
          "pulsesrc is not yet PLAYING");
      g_simple_async_result_complete_in_idle (simple);
      g_object_unref (simple);
      return;
    }

  empathy_mic_monitor_change_microphone_async (priv->mic_monitor,
      source_output_idx, microphone, empathy_audio_src_change_microphone_cb,
      simple);
}

gboolean
empathy_audio_src_change_microphone_finish (EmpathyGstAudioSrc *src,
    GAsyncResult *result,
    GError **error)
{
  empathy_implement_finish_void (src,
      empathy_audio_src_change_microphone_async);
}