/* * audio-example.c * * Builds a pipeline with [ audiotestsource ! autoaudiosink ] and sweeps * frequency and volume. * * Needs gst-plugins-base + gst-plugins-good installed. */ #include #include #include gint main (gint argc, gchar ** argv) { gint res = 1; GstElement *src, *sink; GstElement *bin; GstControlSource *cs1, *cs2; GstTimedValueControlSource *tvcs; GstClock *clock; GstClockID clock_id; GstClockReturn wait_ret; gst_init (&argc, &argv); /* build pipeline */ bin = gst_pipeline_new ("pipeline"); clock = gst_pipeline_get_clock (GST_PIPELINE (bin)); src = gst_element_factory_make ("audiotestsrc", NULL); if (!src) { GST_WARNING ("need audiotestsrc from gst-plugins-base"); goto Error; } sink = gst_element_factory_make ("autoaudiosink", NULL); if (!sink) { GST_WARNING ("need autoaudiosink from gst-plugins-good"); 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; } /* setup control sources */ cs1 = gst_interpolation_control_source_new (); cs2 = gst_interpolation_control_source_new (); gst_object_add_control_binding (GST_OBJECT_CAST (src), gst_direct_control_binding_new (GST_OBJECT_CAST (src), "volume", cs1)); gst_object_add_control_binding (GST_OBJECT_CAST (src), gst_direct_control_binding_new (GST_OBJECT_CAST (src), "freq", cs2)); /* set interpolation mode */ g_object_set (cs1, "mode", GST_INTERPOLATION_MODE_LINEAR, NULL); g_object_set (cs2, "mode", GST_INTERPOLATION_MODE_LINEAR, NULL); /* set control values */ tvcs = (GstTimedValueControlSource *) cs1; gst_timed_value_control_source_set (tvcs, 0 * GST_SECOND, 0.0); gst_timed_value_control_source_set (tvcs, 5 * GST_SECOND, 1.0); gst_object_unref (cs1); tvcs = (GstTimedValueControlSource *) cs2; gst_timed_value_control_source_set (tvcs, 0 * GST_SECOND, 220.0 / 20000.0); gst_timed_value_control_source_set (tvcs, 3 * GST_SECOND, 3520.0 / 20000.0); gst_timed_value_control_source_set (tvcs, 6 * GST_SECOND, 440.0 / 20000.0); gst_object_unref (cs2); /* run for 7 seconds */ clock_id = gst_clock_new_single_shot_id (clock, gst_clock_get_time (clock) + (7 * GST_SECOND)); 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 */ gst_clock_id_unref (clock_id); gst_object_unref (clock); gst_object_unref (bin); res = 0; Error: return (res); }