adding dynparams filter example code

Original commit message from CVS:
adding dynparams filter example code

3 files changed, 535 insertions, 4 deletions

diff --git a/examples/Makefile.am b/examples/Makefile.am
index b5ac1307..97c58aab 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -1,5 +1,3 @@
-# um, we're lacking an api? gst_element_connect_filtered()
+SUBDIRS=dynparams seeking
 
-SUBDIRS=seeking
-
-DIST_SUBDIRS=capsfilter seeking
+DIST_SUBDIRS=capsfilter dynparams seeking
diff --git a/examples/dynparams/Makefile.am b/examples/dynparams/Makefile.am
new file mode 100644
index 00000000..de0a1d9e
--- /dev/null
+++ b/examples/dynparams/Makefile.am
@@ -0,0 +1,7 @@
+examples = filter
+
+noinst_PROGRAMS = $(examples)
+
+# we have nothing but apps here, we can do this safely
+LIBS = $(GST_LIBS) $(GTK_LIBS) -lgstcontrol
+CFLAGS = $(GST_CFLAGS) $(GTK_CFLAGS)
diff --git a/examples/dynparams/filter.c b/examples/dynparams/filter.c
new file mode 100644
index 00000000..7934283a
--- /dev/null
+++ b/examples/dynparams/filter.c
@@ -0,0 +1,526 @@
+/*
+ * filter.c
+ *
+ * demo application for filters using dparams
+ * dparams get their sliders which you can play with
+ *
+ * you can also enter an input and output part of a pipeline
+ */
+
+#include <string.h>
+#include <gtk/gtk.h>
+#include <gst/gst.h>
+#include <gst/control/control.h>
+
+/* filter UI data */
+struct _filter_ui
+{
+  GtkWidget *window;		/* top-level interface window */
+
+  GtkWidget *buttons;		/* all of the control buttons */
+  GtkWidget *parse, *play, *stop; /* control buttons */
+  
+  GtkWidget *feedback;		/* here's where we'll tell you stuff */
+  GtkTextBuffer *fb_buffer;	/* feedback buffer */
+  GtkWidget *selection;		/* the place to input element stuff */
+  GtkWidget *input, *filter, *output; /* the selection widgets */
+  
+  GtkWidget *control;		/* the dynamically generated control UI */
+};
+
+typedef struct _filter_ui _filter_ui_t;
+
+/* back-end data */
+struct _filter_data
+{
+  _filter_ui_t *ui;			/* the UI data */
+  gchar *input_pipe, *output_pipe, *filter_element;
+  gchar *pipe_string;
+  GList *filter_choices;
+
+  gboolean playing;
+  GstElement *input, *output;		/* these are in and out bins */
+  GstElement *pipeline;
+  GstElement *filter;
+};
+
+typedef struct _filter_data _filter_data_t;
+
+/* internal prototypes when they can't be avoided */
+void	cb_remove_and_destroy 	(GtkWidget *widget, gpointer user_data);
+//void	cb_dynparm_value_changed (GtkWidget *widget, gpointer user_data);
+void	cb_dynparm_value_changed (GtkRange *range, GstDParam *dparam);
+
+/* GStreamer helper functions go here */
+  
+/* go through a bin, finding the one pad that is unconnected in the given
+ * direction, and return a ghost pad */
+GstPad *
+gst_bin_find_unconnected_pad (GstBin *bin, GstPadDirection direction, 
+                              gchar *name)
+{
+  GstPad *pad = NULL;
+  GList *elements = NULL;
+  GList *pads = NULL;
+  GstElement *element = NULL;
+
+  g_print ("DEBUG: find_unconnected start\n");
+  elements = (GList *) gst_bin_get_list (bin);
+  /* traverse all elements looking for unconnected pads */
+  while (elements && pad == NULL)
+  {
+    element = GST_ELEMENT (elements->data);
+    g_print ("DEBUG: looking in element %s\n", gst_element_get_name (element));
+    pads = gst_element_get_pad_list (element);
+    while (pads)
+    {
+      /* check if the direction matches */
+      if (GST_PAD_DIRECTION (GST_PAD (pads->data)) == direction)
+      {
+        if (GST_PAD_PEER (GST_PAD (pads->data)) == NULL)
+	{
+	  /* found it ! */
+	  g_print ("DEBUG: found an unconnected pad !\n");
+	  pad = GST_PAD (pads->data);
+	}
+      }
+      if (pad) break; /* found one already */
+      pads = g_list_next (pads);
+    }
+    elements = g_list_next (elements);
+  }
+
+  g_print ("DEBUG: find_unconnected stop\n");
+  if (pad == NULL) /* we didn't find it at all */
+    return NULL;
+  
+  pad = gst_ghost_pad_new (name, pad);
+  return pad;
+}
+
+void
+ui_feedback_add_text (_filter_ui_t *ui, const gchar *text)
+{
+  GtkTextIter iter;
+
+  gtk_text_buffer_get_end_iter (ui->fb_buffer, &iter);
+  gtk_text_buffer_insert (ui->fb_buffer, &iter, text, -1);
+}
+
+void
+ui_feedback_add (_filter_ui_t *ui, const gchar *format, ...)
+{
+  va_list args;
+  gchar *buffer = NULL;
+
+  va_start (args, format);
+  buffer = g_strdup_vprintf (format, args);
+  va_end (args);
+  ui_feedback_add_text (ui, buffer);
+  g_free (buffer);
+}
+
+void
+ui_feedback_clear (_filter_ui_t *ui)
+{
+  gtk_text_buffer_set_text (ui->fb_buffer, "", 0);
+}
+
+/* create the control widget using the element's dynparams 
+ * control is a vbox which we need to empty first */
+void
+ui_control_create (GstElement *element, GtkWidget *control, _filter_ui_t *ui)
+{
+  GtkWidget *hbox = NULL;
+  GtkWidget *widget = NULL;
+  GstDParamManager *dpman = NULL;
+  GstDParam *dparam = NULL;
+  GParamSpec **specs = NULL;
+  int i = 0;
+  
+  g_assert (GTK_IS_VBOX (control));
+
+  /* empty control vbox */
+  g_print ("DEBUG: emptying control widget\n");
+  gtk_container_foreach (GTK_CONTAINER (control), cb_remove_and_destroy, 
+                         (gpointer) control);
+
+  g_print ("DEBUG: adding label to control widget\n");
+  widget = gtk_label_new ("Dynamic Parameters");
+  gtk_container_add (GTK_CONTAINER (control), widget);
+  gtk_widget_show (widget);
+  
+  if ((dpman = gst_dpman_get_manager (element)))
+  {
+    ui_feedback_add (ui, "Found Dynamic Parameters on filter element.\n");
+    specs = gst_dpman_list_dparam_specs (dpman);
+    for (i = 0; specs[i] != NULL; ++i)
+    {
+      hbox = gtk_hbox_new (FALSE, 0);
+      widget = gtk_label_new (g_param_spec_get_name (specs[i]));
+      gtk_container_add (GTK_CONTAINER (hbox), widget);
+      gtk_widget_show (widget);
+      switch (G_PARAM_SPEC_VALUE_TYPE (specs[i])) 
+      {
+        case G_TYPE_INT64:
+	  widget = gtk_hscale_new_with_range (
+	     (gdouble) (((GParamSpecInt64*)specs[i])->minimum),
+	     (gdouble) (((GParamSpecInt64*)specs[i])->maximum),
+	     1.0);
+	  gtk_range_set_value (GTK_RANGE (widget),
+	      (gdouble) ((GParamSpecInt64*)specs[i])->default_value);
+          break;
+
+	case G_TYPE_INT:
+	  widget = gtk_hscale_new_with_range (
+	     (gdouble) (((GParamSpecInt*)specs[i])->minimum),
+	     (gdouble) (((GParamSpecInt*)specs[i])->maximum),
+	     1.0);
+	  gtk_range_set_value (GTK_RANGE (widget),
+	      (gdouble) ((GParamSpecInt*)specs[i])->default_value);
+          break;
+        case G_TYPE_FLOAT:
+	  widget = gtk_hscale_new_with_range (
+	     (gdouble) (((GParamSpecFloat*)specs[i])->minimum),
+	     (gdouble) (((GParamSpecFloat*)specs[i])->maximum),
+	     0.00001);
+	  gtk_range_set_value (GTK_RANGE (widget),
+	      (gdouble) ((GParamSpecFloat*)specs[i])->default_value);
+	  break;
+      }
+      /* create the dparam object */
+      dparam = gst_dpsmooth_new (G_PARAM_SPEC_VALUE_TYPE (specs[i]));
+      g_object_set (G_OBJECT (dparam), "update_period", 2000000LL, NULL);
+      g_assert (gst_dpman_attach_dparam (dpman, 
+	                                 (gchar *) g_param_spec_get_name (specs[i]), 
+					 dparam));
+      gst_dpman_set_mode(dpman, "asynchronous");
+      g_signal_connect (widget, "value-changed",
+	                G_CALLBACK (cb_dynparm_value_changed), dparam);
+			
+      gtk_container_add (GTK_CONTAINER (hbox), widget);
+      gtk_widget_show (widget);      
+    }
+    gtk_container_add (GTK_CONTAINER (control), hbox);
+    gtk_widget_show (hbox);
+  }
+}
+
+/* all the pretty callbacks gather here please */
+void
+cb_remove_and_destroy (GtkWidget *widget, gpointer user_data)
+{
+  GtkContainer *container = GTK_CONTAINER (user_data);
+
+  g_print ("DEBUG: trying to remove widget from a container.\n");
+  gtk_container_remove (container, widget);
+  gtk_widget_destroy (widget);
+}
+
+/* when the scale associated with a dparam changes, respond */
+void
+cb_dynparm_value_changed (GtkRange *range, GstDParam *dparam)
+{
+  /*
+  GstDParam *dparam = GST_DPARAM (user_data);
+  GtkHScale *adj = GTK_HSCALE (widget);
+  */
+  gdouble value = 0.0;
+  g_assert (GST_IS_DPARAM (dparam));
+  g_assert (GTK_IS_RANGE (range));
+
+  value = gtk_range_get_value (range);
+
+  g_print ("DEBUG: setting value to %f\n", value); 
+
+  switch (G_PARAM_SPEC_VALUE_TYPE (GST_DPARAM_PARAM_SPEC (dparam))) 
+  {
+    case G_TYPE_INT64:
+      g_object_set (G_OBJECT (dparam), "value_int64",
+	  (gint64) value, NULL);
+      break;
+
+    case G_TYPE_INT:
+      g_object_set (G_OBJECT (dparam), "value_int",
+	  (gint) value, NULL);
+      break;
+
+    case G_TYPE_FLOAT:
+      g_object_set (G_OBJECT (dparam), "value_float",
+	  (gfloat) value, NULL);
+      break;
+  }
+}
+
+	  
+void
+cb_entry_activate (GtkEntry *entry, gpointer user_data)
+{
+  g_print ("DEBUG: oi ! you activated an entry !\n");
+  g_print ("DEBUG: pipeline: %s\n", gtk_entry_get_text (entry));
+}
+
+void
+cb_play_clicked (GtkButton *button, gpointer *user_data)
+{
+  _filter_data_t *fd = (_filter_data_t *) user_data;
+
+  if (GST_STATE (fd->pipeline) == GST_STATE_PLAYING)
+  {
+    ui_feedback_add (fd->ui, "Pipeline is already playing !\n");
+    return;
+  }
+  gst_element_set_state (fd->pipeline, GST_STATE_PLAYING);
+}
+
+void
+cb_stop_clicked (GtkButton *button, gpointer *user_data)
+{
+  _filter_data_t *fd = (_filter_data_t *) user_data;
+
+  if (GST_STATE (fd->pipeline) != GST_STATE_PLAYING)
+  {
+    ui_feedback_add (fd->ui, "Pipeline is not playing !\n");
+    return;
+  }
+  gst_element_set_state (fd->pipeline, GST_STATE_NULL);
+}
+
+void
+cb_parse_clicked (GtkButton *button, gpointer *user_data)
+{
+  _filter_data_t *fd = (_filter_data_t *) user_data;
+  GtkCombo *filter = GTK_COMBO (fd->ui->filter);
+  GError *error = NULL;
+  GstPad *src_pad, *sink_pad;
+  
+  g_print ("DEBUG: you pressed parse.\n");
+  ui_feedback_clear (fd->ui);
+  ui_feedback_add (fd->ui, "Parsing pipeline ...\n");
+  if (fd->input_pipe) g_free (fd->input_pipe);
+  if (fd->output_pipe) g_free (fd->output_pipe);
+  if (fd->filter_element) g_free (fd->filter_element);
+  fd->input_pipe = g_strdup (gtk_entry_get_text (GTK_ENTRY (fd->ui->input)));
+  fd->output_pipe = g_strdup (gtk_entry_get_text (GTK_ENTRY (fd->ui->output)));
+  /* gtkcombo.h says I can access the entry field directly */
+  fd->filter_element = g_strdup (gtk_entry_get_text (GTK_ENTRY (filter->entry)));
+  g_print ("Input pipeline :\t%s (%d)\n", fd->input_pipe, strlen (fd->input_pipe));
+  g_print ("Filter element :\t%s (%d)\n", fd->filter_element, strlen (fd->filter_element));
+  g_print ("Output pipeline :\t%s (%d)\n", fd->output_pipe, strlen (fd->output_pipe));
+
+  /* try to create in and out bins */
+  if (strlen (fd->input_pipe) == 0)
+  {
+    ui_feedback_add (fd->ui, "Error : try setting an input pipe.\n");
+    return;
+  }
+  if (fd->input) gst_bin_destroy (GST_BIN (fd->input));
+  fd->input = GST_ELEMENT (gst_parse_launch (fd->input_pipe, &error, "bin"));
+  if (error)
+  {
+    ui_feedback_add (fd->ui, "Error : parsing input pipeline : %s\n", 
+	             error->message);
+    g_error_free (error);
+    return;
+  }
+  
+  if (strlen (fd->output_pipe) == 0)
+  {
+    ui_feedback_add (fd->ui, "Error : try setting an output pipe.\n");
+    return;
+  }
+  if (fd->output) gst_bin_destroy (GST_BIN (fd->output));
+  fd->output = GST_ELEMENT (gst_parse_launch (fd->output_pipe, &error, "bin"));
+  if (error)
+  {
+    ui_feedback_add (fd->ui, "Error : parsing output pipeline : %s\n", 
+	             error->message);
+    g_error_free (error);
+    return;
+  }
+
+  /* try to create filter */
+  if (fd->filter) gst_element_destroy (GST_BIN (fd->filter));
+  fd->filter = gst_element_factory_make (fd->filter_element, "filter");
+  if (fd->filter == NULL)
+  {
+    ui_feedback_add (fd->ui, "Error : could not create element %s\n",
+	             fd->filter_element);
+    return;
+  }
+
+  /* set up dynparam controls for filter */
+  ui_control_create (fd->filter, fd->ui->control, fd->ui);
+
+  /* create toplevel bin */
+  fd->pipeline = gst_thread_new ("toplevel");
+
+  /* add the players to it */
+  gst_bin_add_many (GST_BIN (fd->pipeline), 
+                    fd->input, fd->filter, 
+		    fd->output, NULL);
+
+  /* connect filter to input and output bin */
+  src_pad = gst_bin_find_unconnected_pad (GST_BIN (fd->input), GST_PAD_SRC, 
+                                          "source");
+  if (src_pad == NULL)
+  {
+    ui_feedback_add (fd->ui, 
+	             "Error : could not find an unconnected source pad !\n");
+    return;
+  }
+  sink_pad = gst_bin_find_unconnected_pad (GST_BIN (fd->output), GST_PAD_SINK, 
+                                          "sink");
+  if (sink_pad == NULL)
+  {
+    ui_feedback_add (fd->ui, 
+	             "Error : could not find an unconnected sink pad !\n");
+    return;
+  }
+  gst_element_add_pad (fd->input, src_pad);
+  gst_element_add_pad (fd->output, sink_pad);
+
+  gst_element_connect_many (fd->input, fd->filter, fd->output, NULL);
+  
+  if (fd->pipe_string) g_free (fd->pipe_string);
+  fd->pipe_string = g_strdup_printf ("%s ! %s ! %s", fd->input_pipe,
+                                     fd->filter_element, fd->output_pipe);
+  g_print ("Pipeline : %s\n", fd->pipe_string);
+  ui_feedback_add (fd->ui, "Complete parsed pipeline: %s\n", fd->pipe_string);
+
+
+}
+
+/* find out the list of choices for GStreamer filters */
+GList *
+get_filter_choices (void)
+{
+  GList *choices = NULL;
+
+  choices = g_list_append (choices, "volume");
+  choices = g_list_append (choices, "ladspa_lpf");
+  choices = g_list_append (choices, "ladspa_hpf");
+  
+  return choices;
+}
+
+void
+init_data (_filter_data_t *fd)
+{
+  fd->input_pipe = NULL;
+  fd->output_pipe = NULL;
+  fd->filter_element = NULL;
+  fd->pipe_string = NULL;
+  fd->filter_choices = get_filter_choices ();
+
+  /* GStreamer stuff */
+  fd->input = NULL;
+  fd->output = NULL;
+  fd->filter = NULL;
+  fd->pipeline = NULL;
+  fd->playing = FALSE;
+}
+
+void
+create_ui (_filter_ui_t *fui, _filter_data_t *fd)
+{
+  GtkWidget *widget;		/* temporary widget */
+  GtkWidget *vbox;		/* temporary vbox */
+    
+  g_print ("DEBUG: creating top-level window\n");
+  fui->window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+  widget = gtk_vbox_new (FALSE, 0);
+  gtk_container_add (GTK_CONTAINER (fui->window), widget);
+  gtk_window_set_title (GTK_WINDOW (fui->window), "Gee, I can set titles too");
+
+  /* top level window division */
+  g_print ("DEBUG: creating top-level window contents\n");
+  fui->buttons = gtk_hbox_new (FALSE, 0);
+  gtk_container_add (GTK_CONTAINER (widget), fui->buttons);
+  fui->feedback = gtk_text_view_new ();
+  gtk_container_add (GTK_CONTAINER (widget), fui->feedback);
+  fui->selection = gtk_hbox_new (FALSE, 0);
+  gtk_container_add (GTK_CONTAINER (widget), fui->selection);
+  fui->control = gtk_vbox_new (TRUE, 5);
+  gtk_container_add (GTK_CONTAINER (widget), fui->control);
+
+  /* button widget */
+  fui->parse = gtk_button_new_with_label ("Parse");
+  gtk_container_add (GTK_CONTAINER (fui->buttons), fui->parse);
+  g_signal_connect (G_OBJECT (fui->parse), "clicked",
+                    G_CALLBACK (cb_parse_clicked), fd);
+  fui->play = gtk_button_new_with_label ("Play");
+  gtk_container_add (GTK_CONTAINER (fui->buttons), fui->play);
+  g_signal_connect (G_OBJECT (fui->play), "clicked",
+                    G_CALLBACK (cb_play_clicked), fd);
+  fui->stop = gtk_button_new_with_label ("Stop");
+  gtk_container_add (GTK_CONTAINER (fui->buttons), fui->stop);
+  g_signal_connect (G_OBJECT (fui->stop), "clicked",
+                    G_CALLBACK (cb_stop_clicked), fd);
+
+  /* feedback widget */
+  fui->fb_buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (fui->feedback));
+  gtk_text_buffer_set_text (fui->fb_buffer, 
+      "Hello, and welcome to the GStreamer filter demo app !\n"\
+      "I'll be your feedback window for today.\n", -1);
+  
+  /* selection widget */
+  vbox = gtk_vbox_new (FALSE, 0);
+  widget = gtk_label_new ("Input Pipe");
+  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  fui->input = gtk_entry_new ();
+  gtk_entry_set_text (GTK_ENTRY (fui->input), "sinesrc");
+  gtk_container_add (GTK_CONTAINER (vbox), fui->input);
+  gtk_container_add (GTK_CONTAINER (fui->selection), vbox);
+  g_signal_connect (G_OBJECT (fui->input), "activate", 
+                    G_CALLBACK (cb_entry_activate), NULL);
+
+  vbox = gtk_vbox_new (FALSE, 0);
+  widget = gtk_label_new ("Filter");
+  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  fui->filter = gtk_combo_new ();
+  gtk_combo_set_popdown_strings (GTK_COMBO (fui->filter), fd->filter_choices);
+  gtk_container_add (GTK_CONTAINER (vbox), fui->filter);
+  gtk_container_add (GTK_CONTAINER (fui->selection), vbox);
+
+  vbox = gtk_vbox_new (FALSE, 0);
+  widget = gtk_label_new ("Output Pipe");
+  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  fui->output = gtk_entry_new ();
+  gtk_entry_set_text (GTK_ENTRY (fui->output), "osssink"); /* fixme: gconf default ? */
+  gtk_container_add (GTK_CONTAINER (vbox), fui->output);
+  gtk_container_add (GTK_CONTAINER (fui->selection), vbox);
+  g_signal_connect (G_OBJECT (fui->output), "activate", 
+                    G_CALLBACK (cb_entry_activate), NULL);
+
+  /* control widget is dynamically generated */
+  /*
+  g_print ("DEBUG: labeling control area.\n");
+  widget = gtk_label_new ("This is the big control area.");
+  gtk_container_add (GTK_CONTAINER (fui->control), widget);
+  */
+}
+
+
+int
+main (int argc, char *argv[])
+{
+  _filter_data_t filter_data;
+  _filter_ui_t filter_ui;
+  
+  
+  gtk_init (&argc, &argv);
+  gst_init (&argc, &argv);
+  gst_control_init (&argc, &argv);
+
+  init_data (&filter_data);
+  filter_data.ui = &filter_ui;
+
+  create_ui (&filter_ui, &filter_data);
+  gtk_widget_show_all (filter_ui.window);
+
+  gtk_main ();
+  
+  return 0;
+}
+