QMediaPlayer crashes in response to drop event

jboyce

I'm trying to play a video with QMediaPlayer in response to a drag and drop event, and I find that it works or doesn't work depending on where the player is instantiated. Am I doing something obviously wrong here?

Details: Qt 6.4.2, Python 3.11.2, Apple M2 Pro, macOS 13.2.1

(Background: My app allows (a variable number of) videos to be loaded simultaneously when the user drops videos, and I want each to have its own QMediaPlayer. Hence the need to instantiate the player in response to a drop event.)

Here is a minimal example highlighting the issue. This works fine when EARLY = True, and gives a segfault when EARLY = False.

#!/usr/bin/env python3
# encoding: utf-8

import os
import sys
from PySide6.QtWidgets import QApplication
from PySide6.QtCore import QUrl, qVersion
from PySide6.QtWidgets import QMainWindow
from PySide6.QtMultimedia import QMediaPlayer
from PySide6.QtMultimediaWidgets import QVideoWidget

# Drag and drop a video file into the window to play it
# e.g., http://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4

EARLY = True   # segfault when `False`

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.resize(800, 600)
        self.setWindowTitle('Qt6 Video Player')
        self.setAcceptDrops(True)

        if EARLY:
            self.player = QMediaPlayer()

    def dragEnterEvent(self, e):
        if e.mimeData().hasUrls():
            e.acceptProposedAction()

    def dropEvent(self, e):
        paths = [os.path.abspath(url.toLocalFile())
                 for url in e.mimeData().urls()]

        if not EARLY:
            self.player = QMediaPlayer()

        videoWidget = QVideoWidget()
        self.setCentralWidget(videoWidget)

        self.player.errorOccurred.connect(self.mediaErrorOccured)
        self.player.setVideoOutput(videoWidget)
        self.player.setSource(QUrl.fromLocalFile(paths[0]))
        self.player.play()

    def mediaErrorOccured(self, error, message):
        print('error:', error, message)


if __name__ == '__main__':
    print(f'Qt version {qVersion()}')
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    app.exec()

SGaist

Hi and welcome to devnet,

How did you install PySide6 ?

jboyce

@SGaist I used pip as follows:

mkdir env
python3 -m venv env
source env/bin/activate
pip install PySide6

Also I've observed the same crashing behavior on macOS Intel, and Linux (Mint 21.1).

SGaist

@jboyce in that case, you should check the bug report system to see if there's something there and if not, please open a new ticket providing your example.