| /* |
| * audio-example.c |
| * |
| * Builds a pipeline with audiotestsource->alsasink and sweeps frequency and |
| * volume. |
| * |
| * Needs gst-plugin-base installed. |
| */ |
| |
| #include <gst/gst.h> |
| #include <gst/controller/gstcontroller.h> |
| #include <gst/controller/gstinterpolationcontrolsource.h> |
| |
| gint |
| main (gint argc, gchar ** argv) |
| { |
| gint res = 1; |
| GstElement *src, *sink; |
| GstElement *bin; |
| GstController *ctrl; |
| GstInterpolationControlSource *csource1, *csource2; |
| 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)); |
| src = gst_element_factory_make ("audiotestsrc", "gen_audio"); |
| if (!src) { |
| GST_WARNING ("need audiotestsrc from gst-plugins-base"); |
| goto Error; |
| } |
| sink = gst_element_factory_make ("autoaudiosink", "play_audio"); |
| if (!sink) { |
| GST_WARNING ("need autoaudiosink from gst-plugins-base"); |
| goto Error; |
| } |
| |
| gst_bin_add_many (GST_BIN (bin), src, sink, NULL); |
| if (!gst_element_link (src, sink)) { |
| GST_WARNING ("can't link elements"); |
| goto Error; |
| } |
| |
| /* square wave |
| g_object_set (G_OBJECT(src), "wave", 1, NULL); |
| */ |
| |
| /* add a controller to the source */ |
| if (!(ctrl = gst_controller_new (G_OBJECT (src), "freq", "volume", NULL))) { |
| GST_WARNING ("can't control source element"); |
| goto Error; |
| } |
| |
| csource1 = gst_interpolation_control_source_new (); |
| csource2 = gst_interpolation_control_source_new (); |
| |
| gst_controller_set_control_source (ctrl, "volume", |
| GST_CONTROL_SOURCE (csource1)); |
| gst_controller_set_control_source (ctrl, "freq", |
| GST_CONTROL_SOURCE (csource2)); |
| |
| /* Set interpolation mode */ |
| |
| gst_interpolation_control_source_set_interpolation_mode (csource1, |
| GST_INTERPOLATE_LINEAR); |
| gst_interpolation_control_source_set_interpolation_mode (csource2, |
| GST_INTERPOLATE_LINEAR); |
| |
| /* set control values */ |
| g_value_init (&vol, G_TYPE_DOUBLE); |
| g_value_set_double (&vol, 0.0); |
| gst_interpolation_control_source_set (csource1, 0 * GST_SECOND, &vol); |
| g_value_set_double (&vol, 1.0); |
| gst_interpolation_control_source_set (csource1, 5 * GST_SECOND, &vol); |
| |
| g_object_unref (csource1); |
| |
| g_value_set_double (&vol, 220.0); |
| gst_interpolation_control_source_set (csource2, 0 * GST_SECOND, &vol); |
| g_value_set_double (&vol, 3520.0); |
| gst_interpolation_control_source_set (csource2, 3 * GST_SECOND, &vol); |
| g_value_set_double (&vol, 440.0); |
| gst_interpolation_control_source_set (csource2, 6 * GST_SECOND, &vol); |
| |
| g_object_unref (csource2); |
| |
| 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_clock_id_unref (clock_id); |
| gst_object_unref (G_OBJECT (clock)); |
| gst_object_unref (G_OBJECT (bin)); |
| res = 0; |
| Error: |
| return (res); |
| } |