static void
button_play_faster_clicked_cb (GtkButton *button,
			       gpointer   user_data)
{
	GthMediaViewerPage *self = user_data;

	self->priv->rate += 0.25;
	update_player_rate (self);
}
static void
play_faster_button_clicked_cb (GtkButton *button,
			       gpointer   user_data)
{
	GthMediaViewerPage *self = user_data;
	int                 i;

	i = get_nearest_rate (self->priv->rate);
	if (i < G_N_ELEMENTS (default_rates) - 1)
		self->priv->rate = default_rates[i + 1];
	else
		self->priv->rate = default_rates[G_N_ELEMENTS (default_rates) - 1];

	update_player_rate (self);
}
static void
play_slower_button_clicked_cb (GtkButton *button,
			       gpointer   user_data)
{
	GthMediaViewerPage *self = user_data;
	int                 i;

	i = get_nearest_rate (self->priv->rate);
	if (i > 0)
		self->priv->rate = default_rates[i - 1];
	else
		self->priv->rate = default_rates[0];

	update_player_rate (self);
}