gstreamer/gst/sine/demo-dparams.c

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <gtk/gtk.h>
#include <gst/gst.h>
#include <gst/control/control.h>

#define ZERO(mem) memset(&mem, 0, sizeof(mem))

static gint quit_live(GtkWidget *window, GdkEventAny *e, gpointer data) {
  gtk_main_quit();
  return FALSE;
}

static void dynparm_log_value_changed(GtkAdjustment *adj,GstDParam *dparam) {
  gfloat value;
  g_return_if_fail(dparam != NULL);
  g_return_if_fail(GST_IS_DPARAM (dparam));

  value = exp(adj->value);
  
  g_print("setting value to %f\n", value);  
  g_object_set(G_OBJECT(dparam), "value_float", value, NULL);
}

static void dynparm_value_changed(GtkAdjustment *adj,GstDParam *dparam) {
  g_return_if_fail(dparam != NULL);
  g_return_if_fail(GST_IS_DPARAM (dparam));

  g_print("setting value to %f\n", adj->value);  
  g_object_set(G_OBJECT(dparam), "value_float", (gfloat)adj->value, NULL);

}


int main(int argc,char *argv[]) {
  GtkWidget *window;
  GtkWidget *hbox;
  GtkAdjustment *volume_adj;
  GtkAdjustment *freq_adj;
  GtkWidget *volume_slider;
  GtkWidget *freq_slider;

  GstElement *thread, *sinesrc, *volfilter, *osssink;
  GstDParamManager *dpman;
  GstDParam *volume;
  GstDParam *freq;
  GParamSpecFloat *spec;

  gtk_init(&argc,&argv);
  gst_init(&argc,&argv);
  gst_control_init(&argc,&argv);

  /***** construct the pipeline *****/
  
  g_print("creating elements\n");
  thread = gst_thread_new("live-example");
  sinesrc = gst_element_factory_make("sinesrc","sine-source");
  osssink = gst_element_factory_make("osssink","sound-sink");
  volfilter = gst_element_factory_make("volume","volume-filter");
  gst_bin_add_many(GST_BIN(thread), sinesrc, volfilter, osssink, NULL);
  gst_element_link_many(sinesrc, volfilter, osssink, NULL);
  /* this breaks with current alsa oss compat lib */
  g_object_set(G_OBJECT(osssink),"fragment",0x00180008,NULL);
  g_object_set(G_OBJECT(osssink),"sync",FALSE,NULL);

  g_object_set(G_OBJECT(sinesrc),"samplesperbuffer",1024,NULL);
  
  /***** set up the GUI *****/
  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  gtk_window_set_default_size(GTK_WINDOW(window), 80, 400);
  g_signal_connect(window,"delete_event",GTK_SIGNAL_FUNC(quit_live),NULL);
  hbox = gtk_hbox_new(TRUE,0);
  gtk_container_add(GTK_CONTAINER(window),hbox);

  /***** set up the dparams *****/

  freq = gst_dpsmooth_new(G_TYPE_FLOAT);
  
  g_object_set(G_OBJECT(freq), "update_period", 2000000LL, NULL);
  
  /* this defines the maximum slope that this *
  * param can change.  This says that in 50ms *
  * the value can change by a maximum of one semitone *
  * (the log of one semitone is 0.693) */
  g_object_set(G_OBJECT(freq), "slope_delta_float", 0.693F, NULL);
  g_object_set(G_OBJECT(freq), "slope_time", 50000000LL, NULL);
  
  dpman = gst_dpman_get_manager (sinesrc);
  g_assert(gst_dpman_attach_dparam (dpman, "freq", freq));
  gst_dpman_set_mode(dpman, "asynchronous");
  
  spec = (GParamSpecFloat*)gst_dpman_get_param_spec (dpman, "freq");
  freq_adj = (GtkAdjustment*)gtk_adjustment_new((gfloat)log(spec->default_value), 
                                                (gfloat)log(spec->minimum),
                                                (gfloat)log(spec->maximum), 0.1, 0.01, 0.01);


  freq_slider = gtk_vscale_new(freq_adj);
  gtk_scale_set_digits(GTK_SCALE(freq_slider), 2);
  gtk_box_pack_start(GTK_BOX(hbox),freq_slider,TRUE,TRUE,0);

  volume = gst_dpsmooth_new(G_TYPE_FLOAT);
  
  g_object_set(G_OBJECT(volume), "update_period", 2000000LL, NULL);
  
  /* this defines the maximum slope that this *
  * param can change.  This says that in 50ms *
  * the value can change from 0.0 to 1.0 */
  g_object_set(G_OBJECT(volume), "slope_delta_float", 0.1F, NULL);
  g_object_set(G_OBJECT(volume), "slope_time", 50000000LL, NULL); 
  
  dpman = gst_dpman_get_manager (volfilter);
  g_assert(gst_dpman_attach_dparam (dpman, "volume", volume));
  gst_dpman_set_mode(dpman, "asynchronous");
  
  g_object_set(G_OBJECT(volfilter), "mute", FALSE, NULL);

  spec = (GParamSpecFloat*)gst_dpman_get_param_spec (dpman, "volume");
  volume_adj = (GtkAdjustment*)gtk_adjustment_new(spec->default_value, 0.0, 1.2, 0.1, 0.01, 0.01);
  volume_slider = gtk_vscale_new(volume_adj);
  gtk_scale_set_digits(GTK_SCALE(volume_slider), 2);
  gtk_box_pack_start(GTK_BOX(hbox),volume_slider,TRUE,TRUE,0);
  
  /***** set up the handlers and such *****/
  /*gtk_signal_connect(volume_adj,"value-changed",GTK_SIGNAL_FUNC(volume_changed),sinesrc); */
  g_signal_connect(volume_adj,"value-changed",
					 GTK_SIGNAL_FUNC(dynparm_value_changed),
					 volume);

  g_signal_connect(freq_adj,"value-changed",
					 GTK_SIGNAL_FUNC(dynparm_log_value_changed),
					 freq);
  gtk_adjustment_value_changed(volume_adj);
  gtk_adjustment_value_changed(freq_adj);
  
  g_print("starting pipeline\n");
 
  /***** start everything up *****/
  gst_element_set_state(thread,GST_STATE_PLAYING);


  gtk_widget_show_all(window);
  gtk_main();
  
  return 0;
}