windows/thisismy-github-pyplayer/reference/launch.ps1

<#
    launch.ps1 - Starts the PyPlayer GUI and prints its numeric PID.

    PyPlayer is a native PyQt5 (Qt5) desktop app that bundles its own VLC and
    FFmpeg. Its runtime hook resolves bundled libvlc/ffmpeg relative to the exe's
    own folder, so we just set the working directory to the install folder and
    launch pyplayer.exe.

    Output contract: the FIRST line written to stdout is the numeric PID.
    A trailing blank line is emitted AFTER the PID so that when this script is
    captured with  $out = & powershell -File launch.ps1  the result is an ARRAY
    of lines (Object[]) rather than a single String. That makes the harness's
    $out[0] resolve to the PID line ("5148") instead of the first character of a
    scalar string ('5' -> [int] 53). Nothing is printed before the PID.
#>

$ErrorActionPreference = 'Stop'

$InstallDir = (Join-Path (Split-Path $PSScriptRoot -Parent) 'install')
$ExePath    = Join-Path $InstallDir 'pyplayer.exe'

# Start the GUI from within its install folder so bundled DLLs/plugins resolve.
$proc = Start-Process -FilePath $ExePath -WorkingDirectory $InstallDir -PassThru
Write-Output $proc.Id
Write-Output ''