gstreamer/examples/seeking/cdplayer.c

#include <stdlib.h>
#include <glib.h>
#include <gtk/gtk.h>
#include <gst/gst.h>
#include <string.h>

static GList *seekable_elements = NULL;

static GstElement *pipeline;
static GtkAdjustment *adjustment;
static gboolean stats = FALSE;
static guint64 duration;

static guint update_id;

#define UPDATE_INTERVAL 500

static GstElement *
make_cdaudio_pipeline (void)
{
  GstElement *cdaudio;

  cdaudio = gst_element_factory_make ("cdaudio", "cdaudio");
  g_assert (cdaudio != NULL);

  seekable_elements = g_list_prepend (seekable_elements, cdaudio);

  return cdaudio;
}

static gchar *
format_value (GtkScale * scale, gdouble value)
{
  gint64 real;
  gint64 seconds;
  gint64 subseconds;

  real = value * duration / 100;
  seconds = (gint64) real / GST_SECOND;
  subseconds = (gint64) real / (GST_SECOND / 100);

  return g_strdup_printf ("%02" G_GINT64_FORMAT ":%02" G_GINT64_FORMAT ":%02"
      G_GINT64_FORMAT, seconds / 60, seconds % 60, subseconds % 100);
}

typedef struct
{
  const gchar *name;
  const GstFormat format;
}
seek_format;

static seek_format seek_formats[] = {
  {"tim", GST_FORMAT_TIME},
  {"byt", GST_FORMAT_BYTES},
  {"buf", GST_FORMAT_BUFFERS},
  {"def", GST_FORMAT_DEFAULT},
  {NULL, 0},
};


G_GNUC_UNUSED static void
query_durations ()
{
  GList *walk = seekable_elements;

  while (walk) {
    GstElement *element = GST_ELEMENT (walk->data);
    gint i = 0;

    g_print ("durations %8.8s: ", GST_ELEMENT_NAME (element));
    while (seek_formats[i].name) {
      gboolean res;
      gint64 value;
      GstFormat format;

      format = seek_formats[i].format;
      res = gst_element_query (element, GST_QUERY_TOTAL, &format, &value);
      if (res) {
        g_print ("%s %13" G_GINT64_FORMAT " | ", seek_formats[i].name, value);
      } else {
        g_print ("%s %13.13s | ", seek_formats[i].name, "*NA*");
      }
      i++;
    }
    g_print (" %s\n", GST_ELEMENT_NAME (element));
    walk = g_list_next (walk);
  }
}

G_GNUC_UNUSED static void
query_positions ()
{
  GList *walk = seekable_elements;

  while (walk) {
    GstElement *element = GST_ELEMENT (walk->data);
    gint i = 0;

    g_print ("positions %8.8s: ", GST_ELEMENT_NAME (element));
    while (seek_formats[i].name) {
      gboolean res;
      gint64 value;
      GstFormat format;

      format = seek_formats[i].format;
      res = gst_element_query (element, GST_QUERY_POSITION, &format, &value);
      if (res) {
        g_print ("%s %13" G_GINT64_FORMAT " | ", seek_formats[i].name, value);
      } else {
        g_print ("%s %13.13s | ", seek_formats[i].name, "*NA*");
      }
      i++;
    }
    g_print (" %s\n", GST_ELEMENT_NAME (element));
    walk = g_list_next (walk);
  }
}

static gboolean
update_scale (gpointer data)
{
  GstClock *clock;
  guint64 position = 0;
  GstFormat format = GST_FORMAT_TIME;

  duration = 0;
  clock = gst_pipeline_get_clock (GST_PIPELINE (pipeline));

  if (seekable_elements) {
    GstElement *element = GST_ELEMENT (seekable_elements->data);

    gst_element_query (element, GST_QUERY_TOTAL, &format, &duration);
    gst_element_query (element, GST_QUERY_POSITION, &format, &position);
  }

  if (stats) {
    if (clock)
      g_print ("clock:                  %13" G_GUINT64_FORMAT "  (%s)\n",
          position, gst_object_get_name (GST_OBJECT (clock)));
    query_durations ();
    query_positions ();
  }
  if (duration > 0) {
    gtk_adjustment_set_value (adjustment, position * 100.0 / duration);
  }

  return TRUE;
}

static gboolean
start_seek (GtkWidget * widget, GdkEventButton * event, gpointer user_data)
{
  gst_element_set_state (pipeline, GST_STATE_PAUSED);
  gtk_timeout_remove (update_id);

  return FALSE;
}

static gboolean
stop_seek (GtkWidget * widget, GdkEventButton * event, gpointer user_data)
{
  gint64 real = gtk_range_get_value (GTK_RANGE (widget)) * duration / 100;
  gboolean res;
  GstEvent *s_event;
  GList *walk = seekable_elements;

  while (walk) {
    GstElement *seekable = GST_ELEMENT (walk->data);

    g_print ("seek to %" G_GINT64_FORMAT " on element %s\n", real,
        GST_ELEMENT_NAME (seekable));
    s_event =
        gst_event_new_seek (GST_FORMAT_TIME | GST_SEEK_METHOD_SET |
        GST_SEEK_FLAG_FLUSH, real);

    res = gst_element_send_event (seekable, s_event);

    walk = g_list_next (walk);
  }

  gst_element_set_state (pipeline, GST_STATE_PLAYING);
  update_id =
      gtk_timeout_add (UPDATE_INTERVAL, (GtkFunction) update_scale, pipeline);

  return FALSE;
}

static void
play_cb (GtkButton * button, gpointer data)
{
  GstState state;

  gst_element_get_state (pipeline, &state, NULL, NULL);
  if (state != GST_STATE_PLAYING) {
    gst_element_set_state (pipeline, GST_STATE_PLAYING);
    update_id =
        gtk_timeout_add (UPDATE_INTERVAL, (GtkFunction) update_scale, pipeline);
  }
}

static void
pause_cb (GtkButton * button, gpointer data)
{
  GstState state;

  gst_element_get_state (pipeline, &state, NULL, NULL);
  if (state != GST_STATE_PAUSED) {
    gst_element_set_state (pipeline, GST_STATE_PAUSED);
    gtk_timeout_remove (update_id);
  }
}

static void
stop_cb (GtkButton * button, gpointer data)
{
  GstState state;

  gst_element_get_state (pipeline, &state, NULL, NULL);
  if (state != GST_STATE_READY) {
    gst_element_set_state (pipeline, GST_STATE_READY);
    gtk_timeout_remove (update_id);
  }
}

int
main (int argc, char **argv)
{
  GtkWidget *window, *hbox, *vbox,
      *play_button, *pause_button, *stop_button, *hscale;
  struct poptOption options[] = {
    {"stats", 's', POPT_ARG_NONE | POPT_ARGFLAG_STRIP, &stats, 0,
        "Show element stats", NULL},
    POPT_TABLEEND
  };

  gst_init_with_popt_table (&argc, &argv, options);
  gtk_init (&argc, &argv);

  pipeline = make_cdaudio_pipeline ();

  g_signal_connect (pipeline, "deep_notify",
      G_CALLBACK (gst_object_default_deep_notify), NULL);

  /* initialize gui elements ... */
  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  hbox = gtk_hbox_new (FALSE, 0);
  vbox = gtk_vbox_new (FALSE, 0);
  play_button = gtk_button_new_with_label ("play");
  pause_button = gtk_button_new_with_label ("pause");
  stop_button = gtk_button_new_with_label ("stop");

  adjustment =
      GTK_ADJUSTMENT (gtk_adjustment_new (0.0, 0.00, 100.0, 0.1, 1.0, 1.0));
  hscale = gtk_hscale_new (adjustment);
  gtk_scale_set_digits (GTK_SCALE (hscale), 2);
  gtk_range_set_update_policy (GTK_RANGE (hscale), GTK_UPDATE_CONTINUOUS);

  gtk_signal_connect (GTK_OBJECT (hscale),
      "button_press_event", G_CALLBACK (start_seek), pipeline);
  gtk_signal_connect (GTK_OBJECT (hscale),
      "button_release_event", G_CALLBACK (stop_seek), pipeline);
  gtk_signal_connect (GTK_OBJECT (hscale),
      "format_value", G_CALLBACK (format_value), pipeline);

  /* do the packing stuff ... */
  gtk_window_set_default_size (GTK_WINDOW (window), 96, 96);
  gtk_container_add (GTK_CONTAINER (window), vbox);
  gtk_container_add (GTK_CONTAINER (vbox), hbox);
  gtk_box_pack_start (GTK_BOX (hbox), play_button, FALSE, FALSE, 2);
  gtk_box_pack_start (GTK_BOX (hbox), pause_button, FALSE, FALSE, 2);
  gtk_box_pack_start (GTK_BOX (hbox), stop_button, FALSE, FALSE, 2);
  gtk_box_pack_start (GTK_BOX (vbox), hscale, TRUE, TRUE, 2);

  /* connect things ... */
  g_signal_connect (G_OBJECT (play_button), "clicked", G_CALLBACK (play_cb),
      pipeline);
  g_signal_connect (G_OBJECT (pause_button), "clicked", G_CALLBACK (pause_cb),
      pipeline);
  g_signal_connect (G_OBJECT (stop_button), "clicked", G_CALLBACK (stop_cb),
      pipeline);
  g_signal_connect (G_OBJECT (window), "delete_event", gtk_main_quit, NULL);

  /* show the gui. */
  gtk_widget_show_all (window);

  gtk_main ();

  gst_element_set_state (pipeline, GST_STATE_NULL);

  return 0;
}