Pyqt5 and Gstreamer, how to setup layout and draw over the video.

spiderdab

Hi, I'm quite new to qt, but not to code. I need to play a Gstreamer pipeline in a window, with some buttons around and the possibility to draw and write text on the video (an ip camera stream).

what I have working is just playing the video inside a window, but since the video is linked to the window by a WindowId, I cannot put it inside a layout to show other gui widgets.
Any suggestion on how to solve that?

my code:

import sys
import gi
gi.require_version('Gst', '1.0')
gi.require_version('GstVideo', '1.0')
from gi.repository import GObject, Gst, GstVideo
from PyQt5.QtWidgets import *

Gst.init(sys.argv)


class MainWindow(QMainWindow):
    def __init__(self, parent = None):
        super(MainWindow, self).__init__(parent)

        self.pipeline = Gst.parse_launch(
            'videotestsrc name=source ! videoconvert name = convert ! xvimagesink name=sink')  # xvimagesink, ximagesink
        self.source = self.pipeline.get_by_name("source")
        self.videoconvert = self.pipeline.get_by_name("convert")
        self.sink = self.pipeline.get_by_name("sink")

        self.display = QWidget()

        self.setGeometry(100, 100, 640, 480)
        self.setWindowTitle("Prova_gst_qt5")

        self.windowId = self.winId()

    def setup_pipeline(self):

        self.state = Gst.State.NULL
        self.source.set_property('pattern', 0)

        if not self.pipeline or not self.source or not self.videoconvert or not self.sink:
            print("ERROR: Not all elements could be created")
            sys.exit(1)

        # instruct the bus to emit signals for each received message
        # and connect to the interesting signals
        bus = self.pipeline.get_bus()

        bus.add_signal_watch()
        bus.enable_sync_message_emission()
        bus.connect('sync-message::element', self.on_sync_message)

    def on_sync_message(self, bus, msg):
        if msg.get_structure().get_name() == 'prepare-window-handle':
            msg.src.set_window_handle(self.windowId)

    def start_pipeline(self):
        self.pipeline.set_state(Gst.State.PLAYING)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = MainWindow()
    window.setup_pipeline()
    window.start_pipeline()
    window.show()
    sys.exit(app.exec_())

SGaist

Hi and welcome to devnet,

If you are using a recent enough version of Qt, you might be able to simplify your code using a custom pipeline like describe here.

yossiovcharik

I've tested the example ad it seems to be working fine.

Do you, by any chance have similar example for QtQuick (QML) form?

Unsolved Pyqt5 and Gstreamer, how to setup layout and draw over the video.