gstreamer not flushing to the filesink - gstreamer

Question

I have this gstreamer pipeline which works from the coomand line as:
gst-launch-1.0 autovideosrc ! tee name = t ! queue ! omxh264enc !
'video/x-h264, stream-format=(string)byte-stream' ! h264parse ! qtmux
! filesink name=fileSink location=test.mp4 t. ! queue ! videoscale !
video/x-raw, width=480,height=270 ! xvimagesink name=displaySink -e
Now, I am replicating this on the C++ side as follows:
GstElement * pipeline = gst_parse_launch("autovideosrc ! tee name = t ! "
"queue ! omxh264enc ! video/x-h264, "
"stream-format=(string)byte-stream ! h264parse ! "
"qtmux ! filesink name=fileSink location=test.mp4 t. "
"! queue ! videoscale ! video/x-raw, width=480,height=270 ! "
"xvimagesink name=displaySink", &error);</raw>
I connect this to a QT window and play as follows:
GstElement * displaySink = gst_bin_get_by_name (GST_BIN (pipeline), "displaySink");
qDebug() << displaySink;
// prepare the ui
QWidget window;
window.resize(480, 270);
window.show();
WId xwinid = window.winId();
gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY(displaySink), xwinid);
// run the pipeline
qDebug() << "Calling run...";
GstStateChangeReturn sret = gst_element_set_state (pipeline,
GST_STATE_PLAYING);
if (sret == GST_STATE_CHANGE_FAILURE) {
gst_element_set_state (pipeline, GST_STATE_NULL);
gst_object_unref (pipeline);
// Exit application
QTimer::singleShot(0, QApplication::activeWindow(), SLOT(quit()));
}
int ret = app.exec();
window.hide();
gst_element_set_state (pipeline, GST_STATE_NULL);
gst_object_unref (pipeline);
This starts displaying the video stream onto my Qt window and the file test.mp4 gets created and it starts to grow in size. However, when I quit the application, the file is not playable. I have a feeling this is because the last bits or some header information is not written due to me calling:
gst_element_set_state (pipeline, GST_STATE_NULL);
I am speculating that this perhaps closes the pipeline without ensuring that the file is correctly created and finalized. Is there a way to ensure that EOF or EOS is called on the pipeline before closing and ensuring that the file is written properly? This is also a speculation at the moment from my part but something else could be wrong...

Answer 1

Yes sending EOS is necessary..
So before the NULLing of pipe do:
gst_element_send_event(pipeline, gst_event_new_eos());
Edit for checking if EOS passed:
According to documentation:
The EOS event will travel down to the sink elements in the pipeline which will then post the GST_MESSAGE_EOS on the bus after they have finished playing any buffered data.
This means that to check if the EOS event successfully passed through the pipeline you could add bus watch callback with gst_bus_add_watch and check there for GST_MESSAGE_EOS.