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/* GStreamer
*
* Copyright (C) 2010 Wim Taymans <wim.taymans@collabora.co.uk>
*
* 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.
*/
/* An example of synchronized playback and recording.
* The trick is to wait for the playback pipeline to preroll before starting
* playback and recording.
*/
#include <string.h>
#include <gst/gst.h>
/* Define to run the asynchronous version. This requires 0.10.31 of the
* GStreamer core. The async version has the benefit that it doesn't block the
* main thread but it produces slightly less clear code. */
#define ASYNC_VERSION
static GMainLoop *loop;
static GstElement *pipeline = NULL;
static GstElement *play_bin, *play_source, *play_sink;
static GstElement *rec_bin, *rec_source, *rec_sink;
static gboolean
message_handler (GstBus * bus, GstMessage * message, gpointer user_data)
{
switch (GST_MESSAGE_TYPE (message)) {
#ifdef ASYNC_VERSION
case GST_MESSAGE_ELEMENT:{
const GstStructure *str;
str = gst_message_get_structure (message);
if (gst_structure_has_name (str, "GstBinForwarded")) {
GstMessage *orig;
/* unwrap the element message */
gst_structure_get (str, "message", GST_TYPE_MESSAGE, &orig, NULL);
g_assert (orig);
switch (GST_MESSAGE_TYPE (orig)) {
case GST_MESSAGE_ASYNC_DONE:
g_print ("ASYNC done %s\n", GST_MESSAGE_SRC_NAME (orig));
if (GST_MESSAGE_SRC (orig) == GST_OBJECT_CAST (play_bin)) {
g_print
("prerolled, starting synchronized playback and recording\n");
/* returns ASYNC because the sink linked to the live source is not
* prerolled */
if (gst_element_set_state (pipeline,
GST_STATE_PLAYING) != GST_STATE_CHANGE_ASYNC) {
g_warning ("State change failed");
}
}
break;
default:
break;
}
}
break;
}
#endif
case GST_MESSAGE_EOS:
g_print ("EOS\n");
g_main_loop_quit (loop);
break;
case GST_MESSAGE_ERROR:{
GError *err = NULL;
gst_message_parse_error (message, &err, NULL);
g_print ("error: %s\n", err->message);
g_clear_error (&err);
g_main_loop_quit (loop);
break;
}
default:
break;
}
return TRUE;
}
int
main (int argc, char *argv[])
{
GstBus *bus;
gint watch_id;
gst_init (NULL, NULL);
loop = g_main_loop_new (NULL, TRUE);
pipeline = gst_pipeline_new ("pipeline");
#ifdef ASYNC_VERSION
/* this enables messages of individual elements inside the pipeline */
g_object_set (pipeline, "message-forward", TRUE, NULL);
#endif
/* make a bin with the playback elements this is a non-live pipeline */
play_bin = gst_bin_new ("play_bin");
play_source = gst_element_factory_make ("audiotestsrc", "play_source");
play_sink = gst_element_factory_make ("autoaudiosink", "play_sink");
gst_bin_add (GST_BIN (play_bin), play_source);
gst_bin_add (GST_BIN (play_bin), play_sink);
gst_element_link (play_source, play_sink);
/* make bin with the record elements, this is a live pipeline */
rec_bin = gst_bin_new ("rec_bin");
rec_source = gst_element_factory_make ("autoaudiosrc", "rec_source");
rec_sink = gst_element_factory_make ("fakesink", "rec_sink");
gst_bin_add (GST_BIN (rec_bin), rec_source);
gst_bin_add (GST_BIN (rec_bin), rec_sink);
gst_element_link (rec_source, rec_sink);
gst_bin_add (GST_BIN (pipeline), play_bin);
gst_bin_add (GST_BIN (pipeline), rec_bin);
bus = gst_element_get_bus (pipeline);
watch_id = gst_bus_add_watch (bus, message_handler, NULL);
gst_object_unref (bus);
g_print ("going to PAUSED\n");
/* returns NO_PREROLL because we have a live element */
if (gst_element_set_state (pipeline,
GST_STATE_PAUSED) != GST_STATE_CHANGE_NO_PREROLL) {
g_warning ("Expected state change NO_PREROLL result");
}
g_print ("waiting for playback preroll\n");
#ifndef ASYNC_VERSION
/* sync wait for preroll on the playback bin and then go to PLAYING */
if (gst_element_get_state (play_bin, NULL, NULL,
GST_CLOCK_TIME_NONE) != GST_STATE_CHANGE_SUCCESS) {
g_warning ("Error while waiting for state change");
}
g_print ("prerolled, starting synchronized playback and recording\n");
/* returns ASYNC because the sink linked to the live source is not
* prerolled */
if (gst_element_set_state (pipeline,
GST_STATE_PLAYING) != GST_STATE_CHANGE_ASYNC) {
g_warning ("Expected state change NO_PREROLL result");
}
#endif
g_main_loop_run (loop);
g_source_remove (watch_id);
gst_element_set_state (pipeline, GST_STATE_NULL);
gst_object_unref (pipeline);
g_main_loop_unref (loop);
return 0;
}
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