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/* GStreamer
*
* addstream.c: sample application to dynamically add streams to a running
* pipeline
*
* Copyright (C) <2007> 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
static GstElement *pipeline;
static GstClock *theclock;
static GMainLoop *loop;
static GstElement *bin1, *bin2, *bin3, *bin4, *bin5;
/* start a bin with the given description */
static GstElement *
create_stream (const gchar * descr)
{
GstElement *bin;
GError *error = NULL;
bin = gst_parse_launch (descr, &error);
if (error) {
g_print ("pipeline could not be constructed: %s\n", error->message);
g_error_free (error);
return NULL;
}
/* add the bin to the pipeline now, this will set the current base_time of the
* pipeline on the new bin. */
gst_bin_add (GST_BIN_CAST (pipeline), bin);
return bin;
}
static gboolean
pause_play_stream (GstElement * bin, gint seconds)
{
gboolean punch_in;
GstStateChangeReturn ret;
GstClockTime now, base_time, running_time;
/* get current running time, we need this value to continue playback of
* non-live pipelines. */
now = gst_clock_get_time (theclock);
base_time = gst_element_get_base_time (bin);
running_time = now - base_time;
/* set the new bin to PAUSED, the parent bin will notice (because of the ASYNC
* message and will perform latency calculations again when going to PLAYING
* later. */
ret = gst_element_set_state (bin, GST_STATE_PAUSED);
switch (ret) {
case GST_STATE_CHANGE_NO_PREROLL:
/* live source, timestamps are running_time of the pipeline clock. */
punch_in = FALSE;
break;
case GST_STATE_CHANGE_SUCCESS:
/* success, no async state changes, same as async, timestamps start
* from 0 */
case GST_STATE_CHANGE_ASYNC:
/* no live source, bin will preroll. We have to punch it in because in
* this situation timestamps start from 0. */
punch_in = TRUE;
break;
default:
case GST_STATE_CHANGE_FAILURE:
return FALSE;
}
if (seconds)
g_usleep (seconds * G_USEC_PER_SEC);
if (punch_in) {
/* new bin has to be aligned with previous running_time. We do this by taking
* the current absolute clock time and calculating the base time that would
* give the previous running_time. We set this base_time on the bin before
* setting it to PLAYING. */
now = gst_clock_get_time (theclock);
base_time = now - running_time;
gst_element_set_base_time (bin, base_time);
}
/* now set the pipeline to PLAYING */
gst_element_set_state (bin, GST_STATE_PLAYING);
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);
}
static gboolean
perform_step (gpointer pstep)
{
gint step = GPOINTER_TO_INT (pstep);
switch (step) {
case 0:
/* live stream locks on to running_time, pipeline configures latency. */
g_print ("creating bin1\n");
bin1 =
create_stream
("( v4l2src ! ffmpegcolorspace ! timeoverlay ! queue ! xvimagesink name=v4llive )");
pause_play_stream (bin1, 0);
g_timeout_add (1000, (GSourceFunc) perform_step, GINT_TO_POINTER (1));
break;
case 1:
/* live stream locks on to running_time, pipeline reconfigures latency
* together with the previously added bin so that they run synchronized. */
g_print ("creating bin2\n");
bin2 = create_stream ("( alsasrc ! queue ! alsasink name=alsalive )");
pause_play_stream (bin2, 0);
g_timeout_add (1000, (GSourceFunc) perform_step, GINT_TO_POINTER (2));
break;
case 2:
/* non-live stream, need base_time to align with current running live sources. */
g_print ("creating bin3\n");
bin3 = create_stream ("( audiotestsrc ! alsasink name=atnonlive )");
pause_play_stream (bin3, 0);
g_timeout_add (1000, (GSourceFunc) perform_step, GINT_TO_POINTER (3));
break;
case 3:
g_print ("creating bin4\n");
bin4 =
create_stream
("( videotestsrc ! timeoverlay ! ffmpegcolorspace ! ximagesink name=vtnonlive )");
pause_play_stream (bin4, 0);
g_timeout_add (1000, (GSourceFunc) perform_step, GINT_TO_POINTER (4));
break;
case 4:
/* live stream locks on to running_time */
g_print ("creating bin5\n");
bin5 =
create_stream
("( videotestsrc is-live=1 ! timeoverlay ! ffmpegcolorspace ! ximagesink name=vtlive )");
pause_play_stream (bin5, 0);
g_timeout_add (1000, (GSourceFunc) perform_step, GINT_TO_POINTER (5));
break;
case 5:
/* pause the fist live stream for 2 seconds */
g_print ("PAUSE bin1 for 2 seconds\n");
pause_play_stream (bin1, 2);
/* pause the non-live stream for 2 seconds */
g_print ("PAUSE bin4 for 2 seconds\n");
pause_play_stream (bin4, 2);
/* pause the pseudo live stream for 2 seconds */
g_print ("PAUSE bin5 for 2 seconds\n");
pause_play_stream (bin5, 2);
g_print ("Waiting 5 seconds\n");
g_timeout_add (5000, (GSourceFunc) perform_step, GINT_TO_POINTER (6));
break;
case 6:
g_print ("quiting\n");
g_main_loop_quit (loop);
break;
default:
break;
}
return FALSE;
}
int
main (int argc, char *argv[])
{
GstBus *bus;
gst_init (&argc, &argv);
loop = g_main_loop_new (NULL, TRUE);
pipeline = gst_pipeline_new ("pipeline");
/* 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, this will distribute a default clock and
* start running. no preroll is needed */
gst_element_set_state (pipeline, GST_STATE_PLAYING);
/* get the clock now. Since we never set the pipeline to PAUSED again, the
* clock will not change, even when we add new clock providers later. */
theclock = gst_element_get_clock (pipeline);
/* start our actions while we are in the mainloop so that we can catch errors
* and other messages. */
g_idle_add ((GSourceFunc) perform_step, GINT_TO_POINTER (0));
/* go to main loop */
g_main_loop_run (loop);
gst_element_set_state (pipeline, GST_STATE_NULL);
gst_object_unref (bus);
gst_object_unref (pipeline);
gst_object_unref (theclock);
return 0;
}
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