将 GStreamer RTSP 视频管道嵌入到 QT GUI 中

Question

我目前正在使用 IP 摄像机，我需要将其视频源显示到 QT 应用程序中。我已经成功创建了一个 Gstreamer 管道，可以正确显示提要并具有良好的延迟。这是管道：

rtspsrc location=rtsp://192.168.144.25:8554/main.264 latency=100 ! queue ! decodebin ! videoconvert ! gtksink name=sink sync=false

我不确定在应用程序中使用哪个接收器，我正在尝试构建，所以现在我使用 gtksink，但我愿意接受其他建议。

我使用 QT Designer 构建了一个非常简单的 QT 应用程序，其中包含播放和暂停按钮以及用于视频源的小部件：

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'mainwindow.ui'
#
# Created by: PyQt5 UI code generator 5.15.10
#
# WARNING: Any manual changes made to this file will be lost when pyuic5 is
# run again.  Do not edit this file unless you know what you are doing.


from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_Form(object):
    def setupUi(self, Form):
        Form.setObjectName("Form")
        Form.resize(1057, 891)
        self.pushButton = QtWidgets.QPushButton(Form)
        self.pushButton.setGeometry(QtCore.QRect(390, 140, 89, 25))
        self.pushButton.setObjectName("pushButton")
        self.pushButton_2 = QtWidgets.QPushButton(Form)
        self.pushButton_2.setGeometry(QtCore.QRect(560, 140, 89, 25))
        self.pushButton_2.setObjectName("pushButton_2")
        self.status_label = QtWidgets.QLabel(Form)
        self.status_label.setGeometry(QtCore.QRect(470, 60, 111, 17))
        self.status_label.setObjectName("status_label")
        self.video_widget = QtWidgets.QWidget(Form)
        self.video_widget.setGeometry(QtCore.QRect(290, 240, 471, 311))
        self.video_widget.setObjectName("video_widget")

        self.retranslateUi(Form)
        QtCore.QMetaObject.connectSlotsByName(Form)

    def retranslateUi(self, Form):
        _translate = QtCore.QCoreApplication.translate
        Form.setWindowTitle(_translate("Form", "Form"))
        self.pushButton.setText(_translate("Form", "Start"))
        self.pushButton_2.setText(_translate("Form", "Stop"))
        self.status_label.setText(_translate("Form", "Pipeline Status"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    Form = QtWidgets.QWidget()
    ui = Ui_Form()
    ui.setupUi(Form)
    Form.show()
    sys.exit(app.exec_())

以及 Python 应用程序本身：

import sys
import gi
gi.require_version('Gst', '1.0')
gi.require_version('Gtk', '3.0')  # Specify the Gtk version
from gi.repository import Gst, Gtk, GLib
from PyQt5.QtGui import QWindow
from PyQt5.QtWidgets import QApplication, QMainWindow, QVBoxLayout, QWidget
from mainwindow_ui import Ui_Form
import platform

# Initialize GStreamer
Gst.init(None)
Gtk.init()


class VideoPlayer(QMainWindow, Ui_Form):
    def __init__(self):
        super(VideoPlayer, self).__init__()
        self.setupUi(self)

        self.pipeline = None
        self.video_window = None  # This will hold the window handle

        self.pushButton.clicked.connect(self.start_pipeline)
        self.pushButton_2.clicked.connect(self.stop_pipeline)

    def start_pipeline(self):
        if not self.pipeline:
            # Create a DrawingArea for gtksink
            drawing_area = Gtk.DrawingArea()
            drawing_area.set_size_request(640, 480)  # Set size if needed

            GLib.timeout_add(500, drawing_area.realize)
            #drawing_area.realize()  # Ensure the widget is realized

            # Create the pipeline with an initial gtksink
            self.pipeline = Gst.parse_launch(
                f'rtspsrc location=rtsp://192.168.144.25:8554/main.264 latency=100 ! '
                f'queue ! decodebin ! videoconvert ! gtksink name=sink sync=false'
            )
                
             # Get the gtksink element 
            sink = self.pipeline.get_by_name("sink")

            # Connect to the 'realize' signal of the embedded widget
            widget = sink.get_property("widget")
            widget.connect("realize", self.on_widget_realized)


            # Start the pipeline
            self.pipeline.set_state(Gst.State.PLAYING)

            self.status_label.setText("Pipeline Running")

    def on_widget_realized(self, widget):
        self.video_window = widget.get_window().get_xid()
        
        # Find the placeholder widget
        video_placeholder = self.findChild(QWidget, "video_widget")  

        # Create a QWindow from the window ID
        video_window = QWindow.fromWinId(self.video_window)

        # Create the window container and embed the QWindow
        container = QWidget.createWindowContainer(video_window, parent=video_placeholder)

        # Add the container to the video placeholder's layout
        layout = QVBoxLayout(video_placeholder)
        layout.addWidget(container)

    def stop_pipeline(self):
        if self.pipeline:
            # Stop the pipeline
            self.pipeline.set_state(Gst.State.NULL)
            self.pipeline = None

            self.status_label.setText("Pipeline Stopped")


if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = VideoPlayer()
    window.show()
    sys.exit(app.exec_())

现在它确实可以显示了，但我有多个问题。首先，当我启动应用程序时，Gstreamer 总是打开自己的 GTK 显示窗口，而且它似乎也链接到嵌入式窗口，因为如果我关闭它，它也会关闭嵌入式窗口。如果我尝试停止源并使用按钮再次启动它，它将在其自己的弹出窗口中重新启动，如前所述，而不是在 QT UI 窗口中。

我愿意接受任何解决方案，我想要的是一个 QR 应用程序，它可以显示我的视频源，没有任何弹出窗口，并且可以毫无问题地停止和重新启动。另外，我需要同时获得多个视频源，所有视频均来自相似的源（相同的相机型号）。

Answer 1

我正在分享用于在 Qt 接口内渲染管道的解决方案，其中包括将窗口句柄传递给接收器元素（在本例中为实现 GstVideoOverlay 接口的任何元素，例如 glimagesink、xvimagesink 等）

#!/usr/bin/env python3
import sys
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton

import gi
gi.require_version('Gst', '1.0')
gi.require_version('GstVideo', '1.0')
from gi.repository import GObject, Gst, GstVideo

class GUI(QWidget):
    def __init__(self):
        super().__init__()
        self.pipeline_widget = QWidget(self)
        self.pipeline_widget.resize(500,500)
        self.push_button = QPushButton(self)
        self.push_button.setText(">||")
        self.push_button.pressed.connect(self.play_pause)
        self.playing = True
    
    def closeEvent(self, a0) -> None:
        global pipeline
        pipeline.set_state(Gst.State.NULL)
        super().closeEvent(a0)
        sys.exit()

    def play_pause(self):
        global pipeline
        if self.playing:
            pipeline.set_state(Gst.State.PAUSED)
        else:
            pipeline.set_state(Gst.State.PLAYING)

        self.playing = not self.playing


def main(args):
    global pipeline
    _ = QApplication(args)
    w = GUI()

    GObject.threads_init()
    Gst.init(None)

    pipeline_str = f'videotestsrc ! glimagesink name=sink'

    pipeline = Gst.parse_launch(pipeline_str)
    if not pipeline:
        sys.stderr.write('could not create pipeline\n')
        sys.exit(1)

    sink = pipeline.get_by_name('sink')

    win = w.pipeline_widget.winId() # retrieve the window handle
    sink.set_window_handle(win) # pass the handle to the sink

    loop = GObject.MainLoop()
    pipeline.set_state(Gst.State.PLAYING)
    w.show()
    try:
        loop.run()
    except KeyboardInterrupt:
        pass
    except Exception as e:
        print(e)

    # cleanup
    pipeline.set_state(Gst.State.NULL)
    sys.exit()

if __name__ == '__main__':
    main(sys.argv)

这会产生一个如下所示的窗口