I'm building an app for Avalonia which plays videos and shows images on a raspberry pi. I'm able to show text such as the date/time on the bottom of an image, but not on a libvlc control (for now). I see open issues on that, so came up with a hack that might work if I can add a 'logo' to the bottom. My idea is I'd write an image, then load that image in as a logo using 'add option'.
Libvlc allows addoption to be used to add 'command line options'. It's not supported but is my only option to try. I can see that on the command line what I want to do works. When I try it my code looks like:

public void PlayVideo(string path)
    {
        if (view.MediaPlayer != null)
        {
            
            using var media = new Media(libVLC, new System.Uri(path));
            view.IsVisible = true;
            view.MediaPlayer.SetAudioOutput("Built-in Audio Digital Stereo");
            mediaPlayer.Fullscreen = true;
            mediaPlayer.EnableHardwareDecoding = true;                
            media.AddOption("--logo-file=c:\\testfooter.png");
            view.MediaPlayer.Play(media);

        }
    }

that doesn't seem to work. I see some syntax with ":" instead of "--" but I'm not clear on why. Anyone know if my syntax for addoption is right, or are currently doing this?