How to destroy Gst pipeline? - c++

Question

I'm building a pipeline in Gstreamer. I would like to destroy gst pipeline when the webrtc connection is gone. In this current situation, when webrtc connection is established again, I receive old sdp and offers from other pipelines.
Before the pipeline these commands run for the websocket.
QWebSocket *pSocket = websocketServer->nextPendingConnection();
m_client = pSocket;
m_client->sendTextMessage(QStringLiteral("Initiating WEBRTC handshake"));
QObject::connect(pSocket, &QWebSocket::textMessageReceived, this, &c_module_videostream::processTextMessage);
QObject::connect(pSocket, &QWebSocket::binaryMessageReceived, this, &c_module_videostream::processBinaryMessage);
QObject::connect(pSocket, &QWebSocket::disconnected, this, &c_module_videostream::socketDisconnected);
QObject::connect(this, &c_module_videostream::s_JSONReadyToSend, this, &c_module_videostream::sendJSONTextMessage);
QObject::connect(this, &c_module_videostream::s_needImageData, this, &c_module_videostream::startImageDataStream);
QObject::connect(this, &c_module_videostream::s_enoughImageData, this, &c_module_videostream::stopImageDataStream);
Pipeline is created with this command.
pipeline_description = pipeline_description + "appsrc name=CaliCam ! " + "video/x-raw, format=BGR, width=" + width + ", height=" + height + ", framerate=" + fps + "/1 ! " + "videoconvert !"
//"queue max-size-buffers=10 ! "
+ "x264enc bitrate=1000 speed-preset=ultrafast tune=zerolatency key-int-max=10 ! " + "video/x-h264,profile=constrained-baseline !" + "h264parse ! " + "rtph264pay config-interval=-1 name=payloader ! " + "application/x-rtp, media=video, encoding-name=H264, payload=96 !" + "webrtcbin name=webrtcbin_send";
pipeline = gst_parse_launch(pipeline_description.c_str(), &error);
After that here is the start command of the pipeline.
// Start the Pipeline
RCLCPP_INFO_STREAM(nh->get_logger(), MODULE_NAME << "Starting Pipeline");
GstState cur_state;
int returnvalue;
do
{
RCLCPP_INFO_STREAM(nh->get_logger(), MODULE_NAME << "Starting...");
returnvalue = gst_element_set_state(GST_ELEMENT(pipeline), GST_STATE_PLAYING);
usleep(2000000);
gst_element_get_state(GST_ELEMENT(pipeline), &cur_state, NULL, GST_CLOCK_TIME_NONE);
RCLCPP_INFO_STREAM(nh->get_logger(), MODULE_NAME << "Pipeline status " << cur_state << "/" << returnvalue << "/" << (int)GST_STATE_PLAYING);
} while (cur_state != GST_STATE_PLAYING);
// Pipeline is open, Subscribe to Image transport
image_transport_Subscriber = nh->create_subscription<sensor_msgs::msg::Image>("calicam_front/left/image_rect", 1, std::bind(&c_module_videostream::imageCb, this, std::placeholders::_1));
RCLCPP_INFO_STREAM(nh->get_logger(), MODULE_NAME << "subs::" << this->image_transport_Subscriber);
RCLCPP_INFO_STREAM(nh->get_logger(), MODULE_NAME << "Starting Pipeline DONE");
pushImages = true;
I tried to clear the pipeline with these functions but it still remains.
gst_element_set_state(this->pipeline, GST_STATE_NULL);
gst_object_unref(GST_OBJECT(this->pipeline));
gst_object_unref(GST_OBJECT(this->webrtcbin));
gst_object_unref(GST_OBJECT(this->appsrc));