Suggestion: Adding PyQt6 dependency comment in Readme

[ZbindenJoel]

Hi,

Thank you very much for the library and absolutely glorious piece of art that is VLC!
I spent the last days scripting around with a video project on a Raspberry Pi 5 running the standard Raspberry OS and an anaconda environment.
While playing sound was straightforward, I was very much struggling with getting a video player. In most tutorials found online, the player window spawns automatically when starting playback, which was however not the case for me, all without any apparent error message in the logs...

After exploring the examples, I decided to adapt your PyQt example and updating it to PyQt6 in the process. After installing PyQt6 in the environment however, the player suddenly started spawning automatically when starting playback, which brings me to the suggestion in the title.

Would it be possible to add PyQt6 either as a dependency of the package itself, or add a comment in the "Installing the module" section of the Readme file?

I fell on this solution by accident after quite some time searching online and do believe that such a comment would have significant time saving potential for new users.

Cheers and thanks a lot for the consideration!

[oaubert]

I do not quite understand the request. There are currently 2 qt examples, qtvlc.py which uses PyQt4 and pyqt5vlc.py which uses PyQt5. Feel free to propose an updated pyqt6vlc.py, it can be added to the examples.

[ZbindenJoel]

Hi again and thanks for taking the time!
I will try to clarify my request.

I was trying to trigger a simple video on sensor input of the Raspberry Pi5. Building my very own GUI for this seemed overly convoluted, so I followed the first code block in your Documentation:

import vlc

player = vlc.MediaPlayer('file:///tmp/foo.avi')
player.play()
player.get_instance() # returns the corresponding instance

If I understood correctly, these lines are supposed to open a window with a player and start the video. This however did not happen in my case. While sound of my file was playing, there was no window showing the video track, and most notably no error message in the logs pointing to a problem with the player.
After many hours of debugging, I then decided to build my own GUI from scratch...

Surprisingly, after installing PyQt6 in the environment (pip install PyQt6, nothing more), the above lines from the Documentation started spawning the video player, without me having added any additional code (which is also, why I am not suggesting adding a new example).

Since I fell on this solution rather by chance and wasted quite some hours before finding it I would like to help others in my position finding it faster.
All this is why I suggested adding a warning block in the Installing the module section of your documentation. Your section could then read something like this:

You can install the module through PyPI:

pip install python-vlc

(This part is new)

[!WARNING]
If you have trouble spawning your video player, install also PyQt, e.g:

pip install PyQt6

[mrJean1]

There is something magical happening with PyQt6 or Raspberry Pi5 or libvlc on the latter. Therefore, 3 questions ...

1. What does Python's platform.system() return on Raspberry Pi5?

2. Which vlc.py example did your GUI import in the code above on Raspberry Pi5?

3. How did your GUI code make the platform-specific window connection on Rasperry Pi5?

Because, on all platforms (Windows, Linux, macOS, etc.) audio will usually/always play, but video does not. To get the latter, python-vlc must connect libvlc to the window in a platform-specific fashion. Here's a copy of that code from the pyqt5vlc.py example ...

        # The media player has to be 'connected' to the QFrame (otherwise the
        # video would be displayed in it's own window). This is platform
        # specific, so we must give the ID of the QFrame (or similar object) to
        # vlc. Different platforms have different functions for this
        if platform.system() == "Linux": # for Linux using the X Server
            self.mediaplayer.set_xwindow(int(self.videoframe.winId()))
        elif platform.system() == "Windows": # for Windows
            self.mediaplayer.set_hwnd(int(self.videoframe.winId()))
        elif platform.system() == "Darwin": # for MacOS
            self.mediaplayer.set_nsobject(int(self.videoframe.winId())

There is similar code in all the other python-vlc/examples.

[ZbindenJoel]

I prepared an MWE, it seems that the magic thing is the import of the QApllication here. If I get rid of it, the player won't show...

To answer the questions:

1. platform.system() says 'Linux'
2. I think that's exactly the point of my request...I did not write any GUI code (other than the lingering import I kind of "forgot" to delete).
3. I didn't, which however seems to be kind of normal at least on Windows considering the tutorials out there like the one from gfg, which seem to just spawn a player without requiring specific GUI code. Since this didn't work for me, I started with the window connection code in your examples and started building my GUI starting out from the repo's examples and directly porting this to PyQt6. For some reason however, the import is all I need to have a player spawning...

from PyQt6.QtWidgets import QApplication  # <- I think this is the source of the magic

import vlc
import time

instance = vlc.Instance()
player = instance.media_list_player_new()

video_path = "path/to/video.mp4"
media = instance.media_new(video_path)
player.set_media_list(vlc.MediaList([media]))
player.play_item(media)

while True:
    try:
        time.sleep(1)
    except KeyboardInterrupt:
        print("Quitting")
        break

[mrJean1]

Indeed, the magic is in PyQt6 and/or VLC and/or Linux on Raspberry Pi5. One of those must connect VLC to a QtFrame as in this line ...

if platform.system() == "Linux": # for Linux using the X Server
            self.mediaplayer.set_xwindow(int(self.videoframe.winId()))

FWIW, running the MWE example on macOS with Python 3.13.7, PyQt6-6.10.0 and python-vlc 3.0.21203 only plays audio, no video ... as expected.

Lastly, the python-vlc/examples/pyqt5vlc.py example does not work with PyQt6 for several reasons, all related to PyQt6 vs -5 differences. It would be most helpful to create an other example called pyqt6vlc.py and show/explain there the "QtApplication magic".

[oaubert]

Yes, there are many pyqt6-python-vlc on various forums, but no one took the time to propose a good one for inclusion in the examples. Please provide a nice pyqt6 example, so that we can integrate it.

As for the "magical" behavior, my guess after looking quickly through the pyqt6 source code is that it defines some video output module that becomes available, and VLC uses. You should be able to see this by using instance = vlc.Instance("--verbose 3") and looking for messages with main video output and main vout display, and compare between both versions.

[mrJean1]

I tried 5** pyqt6-python-vlc's (on macOS only) and this one is most functional, both the PyQt6 and PySide6 versions.

Perhaps, check with the owner for permission to use both in python-vlc/examples.
__
**) PyQt6 CodeLegacy and CodeLoop. PySide6 player

***) All suffer from one issue, not adjusting the window to the aspect ratio of the media.