Anonymous

/*
 * audio-example.c
 *
 * Build a pipeline with testaudiosource->alsasink
 * and sweep frequency and volume
 *
 */

#include <gst/gst.h>
#include <gst/controller/gstcontroller.h>
#include <ladspa.h>
#include <pthread.h>

gint
main (gint argc, gchar ** argv)
{
  gint res = 1;
  GstElement *src1, *sink, *src2, *src3, *conv1, *conv2, *conv3, *fm, *conv4;	
  GstElement *bin;
  GstController *ctrl;
  GstClock *clock;
  GstClockID clock_id;
  GstClockReturn wait_ret;
  GValue vol = { 0, };

  gst_init (&argc, &argv);
  gst_controller_init (&argc, &argv);

  /* build pipeline */
  bin = gst_pipeline_new ("pipeline");
  clock = gst_pipeline_get_clock (GST_PIPELINE (bin));
  src1 = gst_element_factory_make ("audiotestsrc", "gen_audio1");
  src2 = gst_element_factory_make ("audiotestsrc", "gen_audio2");
  src3 = gst_element_factory_make ("audiotestsrc", "gen_audio3");
  conv1 = gst_element_factory_make ("audioconvert", "conv1");
  conv2 = gst_element_factory_make ("audioconvert", "conv2");
  conv3 = gst_element_factory_make ("audioconvert", "conv3");
  fm = gst_element_factory_make ("ladspa-fmod-fama-oa", "fm");
  conv4 = gst_element_factory_make ("audioconvert", "conv4");
  sink = gst_element_factory_make ("alsasink", "play_audio");
  gst_bin_add_many (GST_BIN (bin), src1, src2, src3, conv1, conv2, conv3, fm, conv4, sink, NULL);
	 
  if ((!gst_element_link (src1, conv1))&&(!gst_element_link (src2, conv2))&&(!gst_element_link (src3, conv3))) {  
    GST_WARNING ("can't link elements");
    goto Error;
  }

  if ((!gst_element_link (conv1, fm))&&(!gst_element_link (conv2, fm))&&(!gst_element_link (conv3, fm))) {  
    GST_WARNING ("can't link elements");
    goto Error;
  }

  if (!gst_element_link (fm, conv4)) {
    GST_WARNING ("can't link elements");
    goto Error;
  }

  if (!gst_element_link (conv4, sink)) {
    GST_WARNING ("can't link elements");
    goto Error;
  }
  
/* square wave */
     g_object_set (G_OBJECT(src1), "wave", 1, NULL);
  

  /* add a controller to the source */
  if (!(ctrl = gst_controller_new (G_OBJECT (src1), "freq", "volume", NULL))) { 
    GST_WARNING ("can't control source element");
    goto Error;
  }

  /* set interpolation */
  gst_controller_set_interpolation_mode (ctrl, "volume", GST_INTERPOLATE_LINEAR);
  gst_controller_set_interpolation_mode (ctrl, "freq", GST_INTERPOLATE_LINEAR);
  
  /* set control values */
  g_value_init (&vol, G_TYPE_DOUBLE);
  g_value_set_double (&vol, 0.0);
  gst_controller_set (ctrl, "volume", 0 * GST_SECOND, &vol);
  g_value_set_double (&vol, 1.0);
  gst_controller_set (ctrl, "volume", 3 * GST_SECOND, &vol);
  g_value_set_double (&vol, 0.0);
  gst_controller_set (ctrl, "volume", 6 * GST_SECOND, &vol);
  g_value_set_double (&vol, 220.0);
  gst_controller_set (ctrl, "freq", 0 * GST_SECOND, &vol);
  g_value_set_double (&vol, 3520.0);
  gst_controller_set (ctrl, "freq", 3 * GST_SECOND, &vol);
  g_value_set_double (&vol, 440.0);
  gst_controller_set (ctrl, "freq", 6 * GST_SECOND, &vol);

  clock_id =
      gst_clock_new_single_shot_id (clock,
      gst_clock_get_time (clock) + (7 * GST_SECOND));

  /* run for 7 seconds */
  if (gst_element_set_state (bin, GST_STATE_PLAYING)) {
    if ((wait_ret = gst_clock_id_wait (clock_id, NULL)) != GST_CLOCK_OK) {
      GST_WARNING ("clock_id_wait returned: %d", wait_ret);
    }
    gst_element_set_state (bin, GST_STATE_NULL);
  }

  /* cleanup */
  g_object_unref (G_OBJECT (ctrl));
  gst_object_unref (G_OBJECT (clock));
  gst_object_unref (G_OBJECT (bin));
  res = 0;
Error:
  return (res);
}