--- /dev/null
+/* GStreamer
+ *
+ * sprinkle.c: sample application to dynamically mix tones with adder
+ *
+ * Copyright (C) <2009> Wim Taymans <wim dot taymans at gmail dot com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/*
+ * Produces a sweeping sprinkle of tones by dynamically adding and removing
+ * elements to adder.
+ *
+ * gcc `pkg-config --cflags --libs gstreamer-0.10` sprinkle2.c -osprinkle2
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+
+static GstElement *pipeline, *adder;
+static GMainLoop *loop;
+
+typedef struct
+{
+ GstElement *src, *fx;
+ GstPad *src_srcpad;
+ GstPad *fx_sinkpad, *fx_srcpad;
+ GstPad *adder_sinkpad;
+ gdouble freq;
+ gfloat pos;
+} SourceInfo;
+
+/* dynamically add the source to the pipeline and link it to a new pad on
+ * adder */
+static SourceInfo *
+add_source (gdouble freq, gfloat pos)
+{
+ SourceInfo *info;
+
+ info = g_new0 (SourceInfo, 1);
+ info->freq = freq;
+ info->pos = pos;
+
+ /* make source with unique name */
+ info->src = gst_element_factory_make ("audiotestsrc", NULL);
+ info->fx = gst_element_factory_make ("audiopanorama", NULL);
+
+ g_object_set (info->src, "freq", freq, "volume", (gdouble) 0.35, NULL);
+ g_object_set (info->fx, "panorama", pos, NULL);
+
+ /* add to the bin */
+ gst_bin_add (GST_BIN (pipeline), info->src);
+ gst_bin_add (GST_BIN (pipeline), info->fx);
+
+ /* get pads from the elements */
+ info->src_srcpad = gst_element_get_static_pad (info->src, "src");
+ info->fx_srcpad = gst_element_get_static_pad (info->fx, "src");
+ info->fx_sinkpad = gst_element_get_static_pad (info->fx, "sink");
+
+ /* get new pad from adder, adder will now wait for data on this pad */
+ info->adder_sinkpad = gst_element_get_request_pad (adder, "sink%d");
+
+ /* link src to fx and fx to adder */
+ gst_pad_link (info->fx_srcpad, info->adder_sinkpad);
+ gst_pad_link (info->src_srcpad, info->fx_sinkpad);
+
+ /* and play the elements, change the state from sink to source */
+ gst_element_set_state (info->fx, GST_STATE_PLAYING);
+ gst_element_set_state (info->src, GST_STATE_PLAYING);
+
+ g_print ("added freq %5.0f, pos %3.1f\n", info->freq, info->pos);
+
+ return info;
+}
+
+/* remove the source from the pipeline after removing it from adder */
+static void
+remove_source (SourceInfo * info)
+{
+ g_print ("remove freq %5.0f, pos %3.1f\n", info->freq, info->pos);
+
+ /* lock the state so that we can put it to NULL without the parent messing
+ * with our state */
+ gst_element_set_locked_state (info->src, TRUE);
+ gst_element_set_locked_state (info->fx, TRUE);
+
+ /* first stop the source. Remember that this might block when in the PAUSED
+ * state. Alternatively one could send EOS to the source, install an event
+ * probe and schedule a state change/unlink/release from the mainthread. */
+ gst_element_set_state (info->fx, GST_STATE_NULL);
+ /* NOTE that the source emits EOS when shutting down but the EOS will not
+ * reach the adder sinkpad because the effect is in the NULL state. We will
+ * send an EOS to adder later. */
+ gst_element_set_state (info->src, GST_STATE_NULL);
+
+ /* unlink from adder */
+ gst_pad_unlink (info->src_srcpad, info->fx_sinkpad);
+ gst_pad_unlink (info->fx_srcpad, info->adder_sinkpad);
+ gst_object_unref (info->src_srcpad);
+ gst_object_unref (info->fx_srcpad);
+ gst_object_unref (info->fx_sinkpad);
+
+ /* remove from the bin */
+ gst_bin_remove (GST_BIN (pipeline), info->src);
+ gst_bin_remove (GST_BIN (pipeline), info->fx);
+
+ /* send EOS to the sinkpad to make adder EOS when needed */
+ gst_pad_send_event (info->adder_sinkpad, gst_event_new_eos ());
+
+ /* give back the pad */
+ gst_element_release_request_pad (adder, info->adder_sinkpad);
+ gst_object_unref (info->adder_sinkpad);
+
+ g_free (info);
+}
+
+/* we'll keep the state of the sources in this structure. We keep 3 sources
+ * alive */
+typedef struct
+{
+ guint count;
+ SourceInfo *infos[3];
+} SprinkleState;
+
+static SprinkleState *
+create_state (void)
+{
+ SprinkleState *state;
+
+ state = g_new0 (SprinkleState, 1);
+
+ return state;
+}
+
+static void
+free_state (SprinkleState * state)
+{
+ SourceInfo *info;
+ gint i;
+
+ for (i = 0; i < 3; i++) {
+ info = state->infos[i];
+ if (info)
+ remove_source (info);
+ }
+
+ g_free (state);
+}
+
+static gboolean
+do_sprinkle (SprinkleState * state)
+{
+ SourceInfo *info;
+ gint i;
+
+ /* first remove the oldest info */
+ info = state->infos[2];
+
+ if (info)
+ remove_source (info);
+
+ /* move sources */
+ for (i = 2; i > 0; i--) {
+ state->infos[i] = state->infos[i - 1];
+ }
+
+ /* add new source, stop adding sources after 10 rounds. */
+ if (state->count < 20) {
+ state->infos[0] = add_source (
+ (gdouble) ((state->count * 100) + 200),
+ ((gfloat) (state->count % 5) / 2.0 - 1.0));
+ state->count++;
+ } else {
+ state->infos[0] = NULL;
+ }
+ return TRUE;
+}
+
+static void
+message_received (GstBus * bus, GstMessage * message, GstPipeline * pipeline)
+{
+ const GstStructure *s;
+
+ s = gst_message_get_structure (message);
+ g_print ("message from \"%s\" (%s): ",
+ GST_STR_NULL (GST_ELEMENT_NAME (GST_MESSAGE_SRC (message))),
+ gst_message_type_get_name (GST_MESSAGE_TYPE (message)));
+ if (s) {
+ gchar *sstr;
+
+ sstr = gst_structure_to_string (s);
+ g_print ("%s\n", sstr);
+ g_free (sstr);
+ } else {
+ g_print ("no message details\n");
+ }
+}
+
+static void
+eos_message_received (GstBus * bus, GstMessage * message,
+ GstPipeline * pipeline)
+{
+ message_received (bus, message, pipeline);
+ g_main_loop_quit (loop);
+}
+
+int
+main (int argc, char *argv[])
+{
+ GstBus *bus;
+ GstElement *filter, *convert, *sink;
+ GstCaps *caps;
+ gboolean res;
+ SprinkleState *state;
+
+ gst_init (&argc, &argv);
+
+ loop = g_main_loop_new (NULL, TRUE);
+
+ pipeline = gst_pipeline_new ("pipeline");
+
+ /* add the fixed part to the pipeline. Remember that we need a capsfilter
+ * after adder so that multiple sources are not racing to negotiate
+ * a format */
+ adder = gst_element_factory_make ("adder", "adder");
+ filter = gst_element_factory_make ("capsfilter", "filter");
+ convert = gst_element_factory_make ("audioconvert", "convert");
+ sink = gst_element_factory_make ("autoaudiosink", "sink");
+
+ caps = gst_caps_new_simple ("audio/x-raw-int",
+ "endianness", G_TYPE_INT, G_LITTLE_ENDIAN,
+ "channels", G_TYPE_INT, 2,
+ "width", G_TYPE_INT, 16,
+ "depth", G_TYPE_INT, 16,
+ "rate", G_TYPE_INT, 44100, "signed", G_TYPE_BOOLEAN, TRUE, NULL);
+ g_object_set (filter, "caps", caps, NULL);
+ gst_caps_unref (caps);
+
+ gst_bin_add_many (GST_BIN (pipeline), adder, filter, convert, sink, NULL);
+
+ res = gst_element_link_many (adder, filter, convert, sink, NULL);
+ g_assert (res);
+
+ /* setup message handling */
+ bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
+ gst_bus_add_signal_watch_full (bus, G_PRIORITY_HIGH);
+ g_signal_connect (bus, "message::error", (GCallback) message_received,
+ pipeline);
+ g_signal_connect (bus, "message::warning", (GCallback) message_received,
+ pipeline);
+ g_signal_connect (bus, "message::eos", (GCallback) eos_message_received,
+ pipeline);
+
+ /* we set the pipeline to PLAYING, the pipeline will not yet preroll because
+ * there is no source providing data for it yet */
+ gst_element_set_state (pipeline, GST_STATE_PLAYING);
+
+ /* and add the function that modifies the pipeline every 100ms */
+ state = create_state ();
+ g_timeout_add (100, (GSourceFunc) do_sprinkle, state);
+
+ /* go to main loop */
+ g_main_loop_run (loop);
+
+ gst_element_set_state (pipeline, GST_STATE_NULL);
+
+ free_state (state);
+ gst_object_unref (bus);
+ gst_object_unref (pipeline);
+
+ return 0;
+}
projects / mafwsubrenderer / blobdiff