/* GStreamer

 *

 * volume.c: sample application to change the volume of a pipeline

 *

 * Copyright (C) <2004> Thomas Vander Stichele <thomas at apestaart dot org>

 *

 * 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., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <math.h>

#include <gst/gst.h>

#include <gtk/gtk.h>

/* global pointer for the scale widget */

GtkWidget *elapsed;

GtkWidget *scale;

#ifndef M_LN10

#define M_LN10 (log(10.0))

#endif

static void

value_changed_callback (GtkWidget * widget, GstElement * volume)

{

  gdouble value;

  gdouble level;

  value = gtk_range_get_value (GTK_RANGE (widget));

  level = exp (value / 20.0 * M_LN10);

  g_print ("Value: %f dB, level: %f\n", value, level);

  g_object_set (volume, "volume", level, NULL);

}

static void

setup_gui (GstElement * volume)

{

  GtkWidget *window;

  GtkWidget *vbox;

  GtkWidget *label, *hbox;

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

  g_signal_connect (window, "destroy", gtk_main_quit, NULL);

  vbox = gtk_vbox_new (TRUE, 0);

  gtk_container_add (GTK_CONTAINER (window), vbox);

  /* elapsed widget */

  hbox = gtk_hbox_new (TRUE, 0);

  label = gtk_label_new ("Elapsed");

  elapsed = gtk_label_new ("0.000");

  gtk_container_add (GTK_CONTAINER (hbox), label);

  gtk_container_add (GTK_CONTAINER (hbox), elapsed);

  gtk_container_add (GTK_CONTAINER (vbox), hbox);

  /* volume */

  hbox = gtk_hbox_new (TRUE, 0);

  label = gtk_label_new ("volume");

  gtk_container_add (GTK_CONTAINER (hbox), label);

  scale = gtk_hscale_new_with_range (-90.0, 10.0, 0.2);

  gtk_range_set_value (GTK_RANGE (scale), 0.0);

  gtk_widget_set_size_request (scale, 100, -1);

  gtk_container_add (GTK_CONTAINER (hbox), scale);

  gtk_container_add (GTK_CONTAINER (vbox), hbox);

  g_signal_connect (scale, "value-changed",

      G_CALLBACK (value_changed_callback), volume);

  gtk_widget_show_all (GTK_WIDGET (window));

}

static void

message_received (GstBus * bus, GstMessage * message, GstPipeline * pipeline)

{

  const GstStructure *s;

  s = gst_message_get_structure (message);

  g_print ("message from \"%s\" (%s): ",

      GST_STR_NULL (GST_ELEMENT_NAME (GST_MESSAGE_SRC (message))),

      gst_message_type_get_name (GST_MESSAGE_TYPE (message)));

  if (s) {

    gchar *sstr;

    sstr = gst_structure_to_string (s);

    g_print ("%s\n", sstr);

    g_free (sstr);

  } else {

    g_print ("no message details\n");

  }

}

static void

eos_message_received (GstBus * bus, GstMessage * message,

    GstPipeline * pipeline)

{

  message_received (bus, message, pipeline);

  gtk_main_quit ();

}

int

main (int argc, char *argv[])

{

  GstElement *pipeline = NULL;

#ifndef GST_DISABLE_PARSE

  GError *error = NULL;

#endif

  GstElement *volume;

  GstBus *bus;

#ifdef GST_DISABLE_PARSE

  g_print ("GStreamer was built without pipeline parsing capabilities.\n");

  g_print

      ("Please rebuild GStreamer with pipeline parsing capabilities activated to use this example.\n");

  return 1;

#else

  gst_init (&argc, &argv);

  gtk_init (&argc, &argv);

  pipeline = gst_parse_launchv ((const gchar **) &argv[1], &error);

  if (error) {

    g_print ("pipeline could not be constructed: %s\n", error->message);

    g_print ("Please give a complete pipeline  with a 'volume' element.\n");

    g_print ("Example: audiotestsrc ! volume ! %s\n", DEFAULT_AUDIOSINK);

    g_error_free (error);

    return 1;

  }

#endif

  volume = gst_bin_get_by_name (GST_BIN (pipeline), "volume0");

  if (volume == NULL) {

    g_print ("Please give a pipeline with a 'volume' element in it\n");

    return 1;

  }

  /* setup message handling */

  bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));

  gst_bus_add_signal_watch_full (bus, G_PRIORITY_HIGH);

  g_signal_connect (bus, "message::error", (GCallback) message_received,

      pipeline);

  g_signal_connect (bus, "message::warning", (GCallback) message_received,

      pipeline);

  g_signal_connect (bus, "message::eos", (GCallback) eos_message_received,

      pipeline);

  /* setup GUI */

  setup_gui (volume);

  /* go to main loop */

  gst_element_set_state (pipeline, GST_STATE_PLAYING);

  gtk_main ();

  gst_element_set_state (pipeline, GST_STATE_NULL);

  gst_object_unref (pipeline);

  return 0;

}