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285 lines
8 KiB
C
285 lines
8 KiB
C
/* GStreamer
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*
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* sprinkle.c: sample application to dynamically mix tones with adder
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*
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* Copyright (C) <2009> Wim Taymans <wim dot taymans at gmail dot com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
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* Boston, MA 02110-1301, USA.
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*/
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/*
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* Produces a sweeping sprinkle of tones by dynamically adding and removing
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* elements to adder.
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*
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* gcc `pkg-config --cflags --libs gstreamer-1.0` sprinkle2.c -osprinkle2
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <gst/gst.h>
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static GstElement *pipeline, *adder;
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static GMainLoop *loop;
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typedef struct
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{
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GstElement *src, *fx;
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GstPad *src_srcpad;
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GstPad *fx_sinkpad, *fx_srcpad;
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GstPad *adder_sinkpad;
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gdouble freq;
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gfloat pos;
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} SourceInfo;
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/* dynamically add the source to the pipeline and link it to a new pad on
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* adder */
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static SourceInfo *
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add_source (gdouble freq, gfloat pos)
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{
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SourceInfo *info;
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info = g_new0 (SourceInfo, 1);
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info->freq = freq;
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info->pos = pos;
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/* make source with unique name */
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info->src = gst_element_factory_make ("audiotestsrc", NULL);
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info->fx = gst_element_factory_make ("audiopanorama", NULL);
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g_object_set (info->src, "freq", freq, "volume", (gdouble) 0.35, NULL);
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g_object_set (info->fx, "panorama", pos, NULL);
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/* add to the bin */
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gst_bin_add (GST_BIN (pipeline), info->src);
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gst_bin_add (GST_BIN (pipeline), info->fx);
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/* get pads from the elements */
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info->src_srcpad = gst_element_get_static_pad (info->src, "src");
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info->fx_srcpad = gst_element_get_static_pad (info->fx, "src");
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info->fx_sinkpad = gst_element_get_static_pad (info->fx, "sink");
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/* get new pad from adder, adder will now wait for data on this pad */
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info->adder_sinkpad = gst_element_get_request_pad (adder, "sink_%u");
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/* link src to fx and fx to adder */
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gst_pad_link (info->fx_srcpad, info->adder_sinkpad);
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gst_pad_link (info->src_srcpad, info->fx_sinkpad);
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/* and play the elements, change the state from sink to source */
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gst_element_set_state (info->fx, GST_STATE_PLAYING);
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gst_element_set_state (info->src, GST_STATE_PLAYING);
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g_print ("added freq %5.0f, pos %3.1f\n", info->freq, info->pos);
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return info;
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}
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/* remove the source from the pipeline after removing it from adder */
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static void
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remove_source (SourceInfo * info)
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{
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g_print ("remove freq %5.0f, pos %3.1f\n", info->freq, info->pos);
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/* lock the state so that we can put it to NULL without the parent messing
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* with our state */
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gst_element_set_locked_state (info->src, TRUE);
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gst_element_set_locked_state (info->fx, TRUE);
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/* first stop the source. Remember that this might block when in the PAUSED
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* state. Alternatively one could send EOS to the source, install an event
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* probe and schedule a state change/unlink/release from the mainthread. */
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gst_element_set_state (info->fx, GST_STATE_NULL);
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/* NOTE that the source emits EOS when shutting down but the EOS will not
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* reach the adder sinkpad because the effect is in the NULL state. We will
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* send an EOS to adder later. */
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gst_element_set_state (info->src, GST_STATE_NULL);
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/* unlink from adder */
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gst_pad_unlink (info->src_srcpad, info->fx_sinkpad);
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gst_pad_unlink (info->fx_srcpad, info->adder_sinkpad);
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gst_object_unref (info->src_srcpad);
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gst_object_unref (info->fx_srcpad);
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gst_object_unref (info->fx_sinkpad);
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/* remove from the bin */
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gst_bin_remove (GST_BIN (pipeline), info->src);
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gst_bin_remove (GST_BIN (pipeline), info->fx);
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/* send EOS to the sinkpad to make adder EOS when needed */
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gst_pad_send_event (info->adder_sinkpad, gst_event_new_eos ());
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/* give back the pad */
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gst_element_release_request_pad (adder, info->adder_sinkpad);
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gst_object_unref (info->adder_sinkpad);
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g_free (info);
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}
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/* we'll keep the state of the sources in this structure. We keep 3 sources
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* alive */
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typedef struct
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{
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guint count;
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SourceInfo *infos[3];
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} SprinkleState;
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static SprinkleState *
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create_state (void)
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{
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SprinkleState *state;
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state = g_new0 (SprinkleState, 1);
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return state;
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}
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static void
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free_state (SprinkleState * state)
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{
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SourceInfo *info;
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gint i;
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for (i = 0; i < 3; i++) {
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info = state->infos[i];
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if (info)
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remove_source (info);
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}
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g_free (state);
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}
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static gboolean
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do_sprinkle (SprinkleState * state)
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{
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SourceInfo *info;
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gint i;
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/* first remove the oldest info */
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info = state->infos[2];
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if (info)
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remove_source (info);
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/* move sources */
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for (i = 2; i > 0; i--) {
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state->infos[i] = state->infos[i - 1];
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}
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/* add new source, stop adding sources after 10 rounds. */
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if (state->count < 20) {
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state->infos[0] = add_source (
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(gdouble) ((state->count * 100) + 200),
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((gfloat) (state->count % 5) / 2.0 - 1.0));
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state->count++;
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} else {
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state->infos[0] = NULL;
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}
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return TRUE;
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}
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static void
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message_received (GstBus * bus, GstMessage * message, GstPipeline * pipeline)
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{
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const GstStructure *s;
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s = gst_message_get_structure (message);
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g_print ("message from \"%s\" (%s): ",
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GST_STR_NULL (GST_ELEMENT_NAME (GST_MESSAGE_SRC (message))),
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gst_message_type_get_name (GST_MESSAGE_TYPE (message)));
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if (s) {
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gchar *sstr;
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sstr = gst_structure_to_string (s);
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g_print ("%s\n", sstr);
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g_free (sstr);
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} else {
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g_print ("no message details\n");
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}
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}
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static void
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eos_message_received (GstBus * bus, GstMessage * message,
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GstPipeline * pipeline)
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{
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message_received (bus, message, pipeline);
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g_main_loop_quit (loop);
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}
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int
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main (int argc, char *argv[])
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{
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GstBus *bus;
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GstElement *filter, *convert, *sink;
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GstCaps *caps;
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gboolean res;
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SprinkleState *state;
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gst_init (&argc, &argv);
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loop = g_main_loop_new (NULL, TRUE);
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pipeline = gst_pipeline_new ("pipeline");
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/* add the fixed part to the pipeline. Remember that we need a capsfilter
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* after adder so that multiple sources are not racing to negotiate
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* a format */
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adder = gst_element_factory_make ("adder", "adder");
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filter = gst_element_factory_make ("capsfilter", "filter");
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convert = gst_element_factory_make ("audioconvert", "convert");
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sink = gst_element_factory_make ("autoaudiosink", "sink");
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caps = gst_caps_new_simple ("audio/x-raw",
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"format", G_TYPE_STRING, "S16LE",
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"channels", G_TYPE_INT, 2, "rate", G_TYPE_INT, 44100, NULL);
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g_object_set (filter, "caps", caps, NULL);
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gst_caps_unref (caps);
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gst_bin_add_many (GST_BIN (pipeline), adder, filter, convert, sink, NULL);
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res = gst_element_link_many (adder, filter, convert, sink, NULL);
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g_assert (res);
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/* setup message handling */
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bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
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gst_bus_add_signal_watch_full (bus, G_PRIORITY_HIGH);
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g_signal_connect (bus, "message::error", (GCallback) message_received,
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pipeline);
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g_signal_connect (bus, "message::warning", (GCallback) message_received,
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pipeline);
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g_signal_connect (bus, "message::eos", (GCallback) eos_message_received,
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pipeline);
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/* we set the pipeline to PLAYING, the pipeline will not yet preroll because
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* there is no source providing data for it yet */
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gst_element_set_state (pipeline, GST_STATE_PLAYING);
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/* and add the function that modifies the pipeline every 100ms */
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state = create_state ();
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g_timeout_add (100, (GSourceFunc) do_sprinkle, state);
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/* go to main loop */
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g_main_loop_run (loop);
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gst_element_set_state (pipeline, GST_STATE_NULL);
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free_state (state);
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gst_object_unref (bus);
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gst_object_unref (pipeline);
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return 0;
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}
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