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https://gitlab.freedesktop.org/gstreamer/gstreamer.git
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79 lines
2.3 KiB
C
79 lines
2.3 KiB
C
/*
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* audio-example.c
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*
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* Build a pipeline with testaudiosource->alsasink
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* and sweep frequency and volume
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*
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*/
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#include <gst/gst.h>
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#include <gst/controller/gst-controller.h>
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gint
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main (gint argc, gchar ** argv)
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{
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gint res = 1;
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GstElement *src, *sink;
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GstElement *bin;
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GstController *ctrl;
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GstClock *clock;
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GstClockID clock_id;
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GstClockReturn wait_ret;
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GValue vol = { 0, };
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gst_init (&argc, &argv);
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gst_controller_init (&argc, &argv);
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// build pipeline
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bin = gst_pipeline_new ("pipeline");
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clock = gst_pipeline_get_clock (GST_PIPELINE (bin));
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/* TODO make this "testaudiosrc", when its ready */
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src = gst_element_factory_make ("sinesrc", "gen_audio");
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sink = gst_element_factory_make ("alsasink", "play_audio");
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gst_bin_add_many (GST_BIN (bin), src, sink, NULL);
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if (!gst_element_link (src, sink)) {
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GST_WARNING ("can't link elements");
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goto Error;
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}
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// add a controller to the source
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if (!(ctrl = gst_controller_new (G_OBJECT (src), "freq", "volume", NULL))) {
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GST_WARNING ("can't control source element");
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goto Error;
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}
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// set interpolation
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gst_controller_set_interpolation_mode (ctrl, "volume",
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GST_INTERPOLATE_LINEAR);
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gst_controller_set_interpolation_mode (ctrl, "freq", GST_INTERPOLATE_LINEAR);
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// set control values
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g_value_init (&vol, G_TYPE_DOUBLE);
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g_value_set_double (&vol, 0.0);
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gst_controller_set (ctrl, "volume", 0 * GST_SECOND, &vol);
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g_value_set_double (&vol, 1.0);
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gst_controller_set (ctrl, "volume", 5 * GST_SECOND, &vol);
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g_value_set_double (&vol, 440.0);
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gst_controller_set (ctrl, "freq", 0 * GST_SECOND, &vol);
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g_value_set_double (&vol, 3520.0);
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gst_controller_set (ctrl, "freq", 3 * GST_SECOND, &vol);
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g_value_set_double (&vol, 880.0);
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gst_controller_set (ctrl, "freq", 6 * GST_SECOND, &vol);
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clock_id =
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gst_clock_new_single_shot_id (clock,
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gst_clock_get_time (clock) + (7 * GST_SECOND));
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// run for 7 seconds
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if (gst_element_set_state (bin, GST_STATE_PLAYING)) {
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if ((wait_ret = gst_clock_id_wait (clock_id, NULL)) != GST_CLOCK_OK) {
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GST_WARNING ("clock_id_wait returned: %d", wait_ret);
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}
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gst_element_set_state (bin, GST_STATE_NULL);
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}
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// cleanup
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g_object_unref (G_OBJECT (ctrl));
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g_object_unref (G_OBJECT (clock));
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g_object_unref (G_OBJECT (bin));
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res = 0;
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Error:
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return (res);
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}
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