Cleanly shutdown / finish encoding when interrupting the recording externally via GNOME Shell's video recording indicator button

[nekohayo]

Affected version

• io.github.seadve.Kooha 2.2.4
• Flatpak: true
• Experimental: false
• Distribution: GNOME 45 (Flatpak runtime)
• Desktop Session: gnome
• Display Server: wayland
• GTK 4.12.5
• Libadwaita 1.4.3
• GStreamer 1.22.10
• Pipewire 0.3.83

Bug summary

When interrupting recording via GNOME Shell, Kooha should still be able to finish encoding a valid file.

Steps to reproduce

1. Start recording with Kooha
2. Click GNOME Shell's orange video recording indicator button in the system menu (top-right corner), as it is faster / more convenient than fishing out Kooha's window from within the pile of windows.

Current result: Kooha outputs a broken video file in this situation.

Expected result: if possible, I would still expect Kooha to finalize the recording into a playable video file (after all, this works fine with GNOME Shell's built-in video recorder), instead of a corrupt file.

[SeaDve]

I have attempted to fix this before, but haven't spent enough time. :D It's harder than I thought; a fix in pipewire may be needed upstream.